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  • IPEN-DOC 29895

    AMAMURA, THAIS; COURROL, DANIELLA; BARBOSA, ANGELA; SILVA JÚNIOR, ILDEFONSO; SILVA, TIAGO da; MIDON, LEONARDO; HEINEMANN, MARCOS B.; CHAMBI, ROSA C. ; MORGANTI, LIGIA ; ISAAC, LOURDES. Proteolytic activity of secreted proteases from pathogenic leptospires and effects on phagocytosis by murine macrophages. Immunobiology, v. 228, n. 5, p. 45, 2023. DOI: 10.1016/j.imbio.2023.152562

    Abstract: Leptospirosis is a zoonosis caused by spirochete bacteria that belong to the genus Leptospira. This disease represents a serious public health problem, especially in developing countries with tropical and subtropical temperatures. Pathogenic leptospires escape from the Complement System, a property that permits them to survive in vitro when in contact with normal human serum (NHS). In a previous study carried out by our group, it was observed that culture supernatants from different pathogenic species of leptospires (SPL) contain proteases that cleave many Complement proteins, including the central molecule C3 and its fragments C3b and iC3b. Our hypothesis is that these proteases, could decrease the phagocytic clearance of leptospires. Using flow cytometry, we observed decreased amounts of CR3 and CR4 in murine peritoneal macrophages treated with SPL for 24 h. By confocal microscopy, we observed reduction in TLR2, CD11b and CD206 levels when these cells were treated with SPL and recombinant thermolysin for 24 h. Furthermore, opsonins such as C3b/iC3b deposited on the surface of pathogenic leptospires were observed to be completely degraded in the presence of SPL or recombinant thermolysin. Finally, we decided to investigate the phagocytosis of pathogenic leptospires by macrophages in the presence of these proteases. We observed an increase of phagocytosis of leptospires opsonized with normal mouse serum even when macrophages were treated with the proteases. However, when opsonized bacteria were also incubated with SPL, recombinant thermolysin and recombinant leptolysin., there was a decline in leptospires phagocytosis. This suggests that the proteolytic activity can affect phagocytosis by peritoneal macrophages mainly through the degradation of opsonins deposited in the membrane of leptospires. These observations lead us to suggest that proteases secreted by pathogenic leptospires could degrade opsonins present in normal serum or deposited in the bacterial membrane as well as cleave or inhibit macrophage surface molecules. Therefore, these proteases could interfere with the recognition and internalization by murine macrophages, favoring the spread of leptospires in the host.

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  • IPEN-DOC 29894

    COURROL, DANIELLA; SILVA, CRISTIANE F. da; CHAMBI, ROSA C.; MORGANTI, LIGIA ; ISAAC, LOURDES; PORTARO, FERNANDA; SILVA, RODRIGO R. da; BARBOSA, ANGELA. Leptospira interrogans leptolysin displays proteolytic activity against complement proteins. Immunobiology, v. 228, n. 5, p. 85, 2023. DOI: 10.1016/j.imbio.2023.152651

    Abstract: Pathogenic Leptospira species are extremely efficient in disseminating in the host, a fact attributed to their ability to escape complement system activation, and to degrade extracellular matrix and other components of the human plasma. Recently, our group evaluated the proteolytic activity of secreted proteins by leptospires, and exoproteome analyzes of these bacteria allowed the identification of some proteases, including the metalloprotease pappalysin-1 domain protein, which we named leptolysin. In this work we produced and functionally characterized leptolysin from L. interrogans to expand our knowledge on this metalloprotease from Leptospira in the processes of invasion and immune evasion. According to in silico analyzes this protease belongs to the category of short pappalysins, also found in other bacteria. Leptolysin is present in all Leptospira species but is more conserved among pathogenic species of the P1 subclade. A preliminary biochemical characterization of its proteolytic activity was performed using FRET (Free Resonance Energy Transfer) peptides. The enzyme exhibited maximum activity at pH 8.0 and 37 C, was active in the presence of different salts and was strongly inhibited by EDTA and 1,10-phenanthroline. It showed a marked preference for arginine residues in the P1 position. The proteolytic activity of recombinant leptolysin on host molecules was also evaluated in vitro and in vivo. The metalloprotease was active against extracellular matrix proteins (proteoglycans and fibronectin), coagulation cascade molecules (fibrinogen and thrombin) and effector proteins of the human complement system (C2 to C9). A leptolysin knockout strain (Dlic13434) was produced and characterized. This strain showed lower survival in normal human serum (SHN) compared to the wild-type strain. However, in a model of epicutaneous infection in hamsters, no attenuation of virulence was observed with the knockout strain, although the bacterial load in the kidneys of these animals was lower than that observed in animals inoculated with the wild-type strain. Finally, data with sera from leptospirosis patients suggest that leptolysin is produced during natural infections by pathogenic leptospires. The characterization of toxins, their targets and mechanisms of action can help in the development of strategies to combat leptospirosis.

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  • IPEN-DOC 29954

    PAIVA, MARCIA M.D.P. ; POZZO, LORENA . Financing the line of care in the first biochemical relapse of prostate cancer after [68Ga] PSMA PET- CT. International Journal of Technology Assessment in Health Care, v. 38, n. S1, p. S57-S57, 2023. DOI: 10.1017/S0266462322001891

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  • IPEN-DOC 29811

    PANOSSIAN, ZEHBOUR; COSTA, ISOLDA ; ROSSI, JESUALDO L. . ICC INTERCORR WCO 2021: A Virtual Edition. Materials Research, v. 25, suppl. 1, 2022. DOI: 10.1590/1980-5373-MR-2023-E002

    Abstract: Brazil, once again, organized one of the world’s most significant corrosion events, the ICC - INTERNATIONAL CORROSION CONGRESS. In 1978, the 7th edition of the congress was held by ABRACO, in Rio de Janeiro, under the direction of our Dr. Aldo Cordeiro Dutra, chairman of the Executive Committee. To intertwine two events, the 21st ICC was held together with the traditional INTERCORR, the most representative corrosion and corrosion prevention event held in Brazil, organized by ABRACO, in its 8th edition, which included the workshop “Corrosion and Green Energy”, an event of the World Corrosion Organization (WCO). Thus, the ICC INTERCORR WCO 2021 was arranged with this strong partnership.The institutions responsible for organizing the ICC INTERCORR WCO 2021 were: the Brazilian Corrosion Association (ABRACO), the International Corrosion Council (ICC), and the World Corrosion Organization (WCO). To overcome a new post-pandemic Covid-19 reality, the event occurred virtually from July 20th to 23rd, 2021.The ICC INTERCORR WCO 2021 has become a reference for developing the industrial sector, being an excellent forum for presenting new technologies, disseminating knowledge, prospecting for brands, business opportunities and expanding relationships. Its main objective was to encourage the exchange of knowledge between researchers, technicians, professionals, and companies, whether nationally or globally.The ICC INTERCORR WCO 2021 program included the presentation of 6 plenary conferences, 19 lectures, and more than 220 technical articles by renowned specialists from different countries such as Germany, India, Egypt, USA, Portugal, Australia, Italy, Sweden, Spain, Brazil, among others.Today´s moment highlights the importance of promoting such an event in the country, aiming to find solutions to contribute to the recovery that the industrial sector needs. Maintaining the integrity of assets and minimizing operating and maintenance costs are highly relevant concerns in our daily lives, directly impacting the productive sector.Therefore, on behalf of the Executive Committee, we would like to thank all participants and members of the local organizing committee and the scientific committee. We also sincerely thank the support team for collaborating before, during and after this highly successful event.

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  • IPEN-DOC 29703

    GOMES, ANDERSON S.L.; SOUZA, EUNEZIO T. de; ZEZELL, DENISE M. . Latin America Optics and Photonics 2022: introduction to the feature issue. Applied Optics, v. 62, n. 8, p. 1-2, 2023. DOI: 10.1364/AO.489414

    Abstract: The 2022 Latin America Optics and Photonics Conference (LAOP 2022), the major international conference sponsored byOptica in Latin America, returned to Recife, Pernambuco, Brazil, after its first edition in 2010.Held every two years since (except for 2020), LAOP has the explicit objective to promote Latin American excellence in optics and photonics research and support the regional community. In the 6th edition in 2022, it featured a comprehensive technical program with recognized experts in fields critical to Latin America, highly multidisciplinary, with themes frombiophotonics to2Dmaterials. The 191 attendees of LAOP2022 listened to five plenary speakers, 28 keynotes, 24 invited talks, and 128 presentations, including oral and posters

    Palavras-Chave: optical activity; photon emission; lasers; fiber optics; meetings

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  • IPEN-DOC 29727

    BRANDAO, ULISSES ; SPINACE, ESTEVAM V. ; SEKO, MURILO H.; FERREIRA, WILLIAM de P.. Projeto e construção de um sistema de aquecimento por micro-ondas de baixo custo para avaliação de susceptores. Anais do Workshop de Micro-ondas, v. 1, n. 6, p. 1-4, 2022. DOI: 10.5281/zenodo.7857092

    Abstract: Este trabalho consistiu no projeto e construção de um forno de micro-ondas de 2,45 GHz, destinado à avaliação de susceptores a serem utilizados como catalisadores, em temperaturas de 400 a 1.100 ºC. Sua construção baseou-se em simulações feitas em computador, seguida de testes e modificações para sua funcionalização.

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  • IPEN-DOC 29677

    MORALES, J.M.G.; TORTAMANO-NETO, P.; TODESCAN, F.F.; ANDRADE JUNIOR, J.C.S. de; MAROTTI, J.; ZEZELL, D.M. . Resonance frequency analysis of dental implants after laser therapy. Clinical Oral Implants Research, v. 21, n. 10, p. 1045-1045, 2010. DOI: 10.1111/j.1600-0501.2010.01994.x

    Abstract: Background: The importance of primary stability in implant placement for long-term success is well known in the literature. The resonance frequency analysis technique has extensively been used in experimental and clinical research for the last 10 years, for assessing primary stability. The benefits of low-level laser therapy in bone tissue are already consolidated in the literature, however, little is known about its benefits on improvement of stability of dental implants. Aim: The aim of this randomdouble blind clinical study was to investigate whether stability of titanium implants can be enhanced by low-level laser therapy during the osseointegration process when measured by means of resonance frequency analysis. Methods: Thirty implants (n¼30) were placed in the posterior region of partially edentulous mandible of eight adult patients, after following several inclusion criteria and were distributed bilaterally in agreement with the prosthetic requirement. The implants on the experimental side were randomly submitted to low-level laser therapy (830 nm, 86mW, 92.1 J/cm2, 2.57 J, 3 s/ point, at 20 points), and on the control side the laser irradiation was only simulated. The first irradiation was performed in the immediate postoperative period, and it was repeated every 48 h in the first 14 days. The initial implant stability quotient of the implants was measured by means of resonance frequency analyzer (Osstells). New implant stability quotient measurements were made after 10 days, 3, 6, 9 and 12 weeks. ANOVA for repeated measurements and Bonferroni test were used to assess statistically significant differences. Results: The initial implant stability quotient values ranged from 65 to 84, with a mean of 76. The irradiated side showed significant drop in stability from the 10th day until the sixth week only (P¼0.028), and presenting a gradual increase from the sixth to the 12th week. In the control side, the mean implant stability quotient increased up to the third week, decreased in the sixth week, and then began to grow again. The highest stability values were observed in the 10th day in the irradiated group, and the lowest in the sixth week in both groups. No statistical differences were detected among the ISQ means in the two groups for each of the six times observation. Conclusions and clinical implications: No evidence was found of any effect of low-level laser therapy on implants’ stability when measured by resonance frequency analysis. Because high primary stability and good bone quality are of major relevancy for a rigid bone–implant interface, additional low-level laser therapy under these conditions may have little impact macroscopically. Further researches under different bone conditions are necessary for a better understanding of the occurrences at bone/implant interface.

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  • IPEN-DOC 29676

    ANA, P.A. ; TABCHOURY, C.P.M.; CURY, J.A.; ZEZELL, D.M. . Effect of Er,Cr:YSGG laser and fluoride application on enamel demineralization. Caries Research, v. 41, n. 4, p. 325-326, 2007. DOI: 10.1159/000103637

    Abstract: This study evaluated the influence of sub-ablative Er,Cr:YSGG laser and topical fluoride application on incipient caries development in vitro. One hundred and sixty human enamel slabs were ramdomly divided into eight equal groups: (1) untreated (control); (2–4) irradiated with Er,Cr:YSGG laser at 0.25, 0.50 and 0.75 W, respectively; (5) treated with acidulated phosphate fluoride (APF; 1.23% F) for 4 min; (6–8) pre-irradiated with Er,Cr:YSGG laser at 0.25, 0.50 and 0.75 W, respectively and subjected to APF application. All groups were submitted to pH-cycling simulating a cariogenic challenge, and after 10 cycles mineral loss ( Δ Z) was measured in enamel. Calcium, inorganic phosphorus (P i ) and fluoride concentrations were also measured in the demineralizing and remineralizing pH-cycling solutions. Data were analyzed by ANOVA ( α = 0.05). No differences in Δ Z were found between laser irradiation at 0.25 W, 0.50 W and controls, while after laser irradiation at 0.75 W (Group 4) and application of APF (Group 5) there was a significant decrease in Δ Z. Laser irradiation at 0.50 and 0.75 W prior to APF application there was a significantly lower Δ Z than in other groups. A significant increase in Ca and P i concentrations was observed in demineralizing solutions compared to the initial concentrations, but no significant changes in Ca and P i concentrations were detected between any groups. A significant decrease in fluoride concentration was observed in pH-cycling solutions of control and 0.25 W laser groups, while the association of laser at 0.50 and 0.75 W with fluoride promoted an increase of fluoride content in remineralizing solutions. In conclusion, Er,Cr:YSGG laser irradiation at 0.50 and 0.75 W, associated with fluoride, seems to be a good alternative for reducing enamel demineralization.

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  • IPEN-DOC 29675

    ESTEVES-OLIVEIRA, M.; ZEZELL, D.M. ; VELLOSO, W.F.; MEISTER, J.; FRANZEN, R.; LAMPERT, F.; EDUARDO, C.P.; APEL, C.. Low fluence CO2 laser (10.6 μm) parameters for caries prevention. Caries Research, v. 41, n. 4, p. 325-325, 2007. DOI: 10.1159/000103637

    Abstract: Although CO 2 laser irradiation can decrease enamel demineralization, thermal damage to the surface is a common side effect. The occurrence of fissures and cracks may compromise in vivo application. Therefore, the aim of the present study was to find CO 2 laser (10.6 μm) parameters resulting in maximum caries- preventive effect with the lowest thermal damage. Five low fluences of 0.12, 0.29, 0.39, 0.50 and 0.60 J/cm 2 combined with high repetition rates of 500, 154, 167, 182, 187 Hz, respectively and 10 μs pulse duration were chosen for the experiments. 78 bovine enamel cubes were divided into 5 laser groups and one control. After treatment the samples were submitted to an 8-day pH-cycling regime. Demineralization was assessed by lesion depth measurements with a polarized-light microscope. The temperature rise at the enamel surface and the propagation into deeper layers were calculated using a finite element model. Surface morphology was evaluated by SEM. All laser groups resulted in statistically significant lower lesion depths than the control group (ANOVA; p < 0.05). Morphologically, the two lowest fluences resulted in no surface changes. The calculated temperature rise at 1.5 mm depth was less than 5 ° C in all groups. In the present in vitro study irradiation with 0.12 J/cm 2 , 500 Hz and 2500 pulses of CO 2 laser increased enamel caries resistance without causing undesirable surface damage or excessive temperature rise.

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  • IPEN-DOC 29665

    WETTER, NIKLAUS ; FREJLICH, JAIME. Editorial. Selected Papers from RIAO/OPTILAS 2007 (Campinas, São Paulo, Brazil, 21-26 October 2007). Journal of Optics A: Pure and Applied Optics, v. 10, n. 10, p. 1-1, 2008. DOI: 10.1088/1464-4258/10/10/100201

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  • IPEN-DOC 29658

    AMANCIO, CARLOS T.; JAKUTIS NETO, JONAS ; WETTER, NIKLAUS U. ; BONFIM JÚNIOR, FRANCISCO A. ; KASSAB, LUCIANA R.P.. Estudo do mecanismo de conversão ascendente no visível em vidros de telureto codopados com Er3+ e Yb3+. Boletim Técnico da Faculdade de Tecnologia de São Paulo, v. 23, 2007.

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  • IPEN-DOC 29657

    ASSUMPCAO, THIAGO A.A. de; JAKUTIS NETO, JONAS ; WETTER, NIKLAUS U. ; KASSAB, LUCIANA R.P.. Emissão de luz azul em amostras de germanato dopadas com Tm:Yb e Tm:Yb:Nd. Boletim Técnico da Faculdade de Tecnologia de São Paulo, v. 21, 2006.

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  • IPEN-DOC 29656

    LIMA, B.L.S. de; COURROL, L.C.; KASSAB, L.R.P.; DEL CACHO, V.D.; GOMES, L. ; WETTER, N.U. . Estudo de processos de conversão ascendente em vidros dopados com Nd3+. Boletim Técnico da Faculdade de Tecnologia de São Paulo, v. 15, p. 51-51, 2003.

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  • IPEN-DOC 29655

    DEL CACHO, VANESSA D.; KASSAB, LUCIANA R.P.; COURROL, LILIA C.; WETTER, NIKLAUS U. . Propriedades espectroscópicas de vidros de fluorborato de chumbo dopados com Nd3+ para uso em laser de estado sólido. Boletim Técnico da Faculdade de Tecnologia de São Paulo, v. 13, p. 27-27, 2002.

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  • IPEN-DOC 29503

    MONTEIRO, LUCILENA R. ; OLIVEIRA, MERCIA L.; MENEZES, MARIO O. ; POZZO, LORENA . Exploratory analysis of a Brazilian real-world open database applied to prostate cancer. International Journal of Technology Assessment in Health Care, v. 38, S1, p. S97-S98, 2022. DOI: 10.1017/S0266462322002835

    Abstract: Introduction. Prostate cancer was the second most frequent cancer and the fifth leading cause of cancer death among men in 2020. The incidence rates vary substantially in countries with different Human Development Indexes (HDI), while the mortality rates decrease with improved access to the health system, availability of therapies and earlier detection. Worldwide, population-based cancer registries are important tools for planning and managing health systems. The Fundação Oncocentro de São Paulo (FOSP) is responsible to collect, clean and publicize data from cancer treatment institutions. This study aimed to describe retrospectively the demographic and clinical profile of prostate cancer (PC) in Brazil using this database. It is not an incidence study as data is representative only from specific institutions. Methods. This was a retrospective observational study of the years 2000 to 2020 from analysis of the publicly available FOSP database (http://www.fosp.saude.sp.gov.br). The records were extracted, merged, and cleaned using a fully documented and validated data process. Only patients included on the register with a primary PC diagnosis were considered. Results. From January 2010 to June 2020, there were 943,660 patients diagnosed with C61 in FOSP database for the considered time period. The majority of the FOSP database records are from patients who live and/or were born in SP (91.8 and 58.4%, respectively) orMG(2.8 and 10.5%, respectively). The mean age of PC at baseline was 69 years. Considering the stage of the disease, the mean ages are 55, 70, 67, 66 and 61, for stages 0, 1, 2, 3 and 4, respectively. This cohort was also analyzed in relation to treatments received, and status at the end of treatment (51.3% are disease-free, 18.4% are alive with cancer, and 30.3% are dead). Conclusions. FOSP population-based cancer registries are a powerful tool to obtain information for planning, and improving the management of healthcare services especially for São Paulo.

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  • IPEN-DOC 29501

    ARAUJO, JOAO V. ; MILAGRE, MARIANA X. ; GABBARDO, ALINE D. ; KLUMPP, RAFAEL E. ; COSTA, ISOLDA . The effect of tartaric-sulfuric acid (TSA) anodizing on the corrosion resistance of the AA7475-T761. ECS Meeting Abstracts, v. MA2022-02, 2022. DOI: 10.1149/MA2022-02142475mtgabs

    Abstract: The microstructure of the high strength aluminum alloy, AA7475–T761, in the as-received condition was characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy, and statistical analyses of grain size and micrometer precipitates distribution and density were performed. An anodic aluminum oxide (AAO) film was potentiostatically grown on the alloy in tartaric sulfuric acid (TSA). The anodizing behavior of the alloy and the mechanisms of localized corrosion initiation and propagation in bare (not anodized) and anodized conditions were discussed. The alloy corrosion behavior was investigated in sodium chloride solutions using electrochemical techniques (cyclic potentiodynamic polarization) and the morphology and extent of corrosion propagation was investigated through optical microscopy, optical profilometry and scanning electron microscopy analyses. It was observed that the two alloy surface conditions (bare and anodized) play different roles in the propagation of the localized corrosion process. The bare alloy presented lower localized corrosion potentials and the propagation of the localized corrosion was shallower, but more heavily distributed, than in the anodized condition. However, the alloy in the anodized condition presented lower repassivation potentials due to the deeper pits formed. In addition, the variability of pitting potentials for the anodized condition was high, due to the heterogenous structure of the AAO film formed, and dependent on the time and drying storage conditions previous to electrochemical characterizations. The electrochemical results were correlated with the microstructural characteristics of the oxide surface film of the alloy in both conditions, bare (not anodized) and anodized.

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  • IPEN-DOC 29208

    FONTES-OLIVEIRA, Y.R. ; CARAMEL-JUVINO, A. ; AVELINO, S.G. ; ZEZELL, D.M. . Protocolos de associação de flúor e laser de alta potência (Nd:YAG) na prevenção da cárie: revisão de literatura. Brazilian Oral Research, v. 36, suppl 1, p. 346-346, 2022.

    Abstract: Avaliar os protocolos publicados para prevenção da cárie utilizando associação de flúor e laser Nd:YAG. Foram utilizadas seis bases de dados: Web-of-Science, PubMed, ResearchGate, Google Acadêmico, LILACS e Scielo. Dos 115 artigos inicialmente coletados, foram excluídas as duplicatas, artigos com dentes bovinos, artigos sem flúor gel ou que abordavam erosão. Foram selecionados 12 artigos. Sobre os efeitos do tratamento, os artigos relataram que a irradiação laser promove fusão e re-solidificação da superfície, tornando-a mais ácido-resistente. Quando associado a fluoretos, este laser aumenta a superfície de contato para a ação do flúor, potencializando os seus efeitos. Analisando os parâmetros utilizados na irradiação, a maior parte (50%) usou 0,6W de potência e 84,9 J/cm² de fluência, seguido pelos valores menores 0,5W e 70,7 J/cm² (16,6%). Estes parâmetros foram considerados seguros em estudos que avaliam a possibilidade de dano térmico à polpa. Dentre os estudos que compararam os efeitos da aplicação de flúor prévia ou posteriormente à irradiação laser, apenas 8,3% relataram que o tratamento sinérgico com laser de Nd:YAG e flúor não foi mais eficaz do que o flúor isolado. Já 33,3% apresentaram melhores efeitos com a aplicação de flúor depois do laser e 8,3% obtiveram melhores resultados com aplicação antes do laser. 8,3% concluíram que o resultado independe da ordem. O protocolo de 0,6W de potência e 84,9 J/cm² de fluência, com aplicação de flúor posterior a irradiação laser, apresentou resultados satisfatórios na prevenção da cárie para a maioria dos estudos.

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  • IPEN-DOC 29207

    VARDASCA, I.S. ; REGIS, M.A. ; ZEZELL, D.M. ; FRANCCI, C. . O uso de fontes de luz em protocolos clareadores: alteração de cor, temperatura, transmitância e irradiância: estudo in vitro. Brazilian Oral Research, v. 36, suppl 1, p. 306-306, 2022.

    Abstract: O objetivo do presente estudo foi avaliar as alterações de cor superficial, temperatura, transmitância e irradiância de diferentes fontes de luz em alguns protocolos de clareamento em consultório com peróxido de hidrogênio (PH) de baixa concentração. 90 blocos de esmalte/dentina humanos foram pigmentados e separados em 9 grupos(n=10): SG-SL (sem gel-sem luz), SG-VIO (sem gel, com exposição ao LED violeta), PH35%-SL (sem luz), PH17,5%-SL, PH6%-SL, PH17,5%-AZUL (com exposição ao LED azul), PH6%-AZUL, PH%17,5-VIO (exposição ao LED violeta) e PH6%-VIO. A avaliação da cor foi realizada 7, 14 e 21 dias após o início e 14 dias após o término do protocolo de clareamento com espectrofotômetro, com os valores L*a*b* de reflectância, através do whiteness index (ΔWID ). A análise da temperatura foi realizada com um termopar, a transmitância das luzes com uma esfera integradora e a irradiância das luzes com um powermeter. ANOVA com post-hoc Tukey para as análises de alteração de cor, temperatura e transmitância. O teste de Mann-Whitney foi utilizado para a irradiância. Como resultado, os grupos PH17,5 apresentaram (ΔWID ) similar ao PH35%, independente das fontes de luz. Todos os protocolos irradiados com fontes de luz apresentaram alteração de temperatura maior de 5,5ºC, exceto SG-VIO. A transmitância foi maior no LED azul e no PH17,5%, e a irradiância foi maior no LED azul. Conclui-se que o uso de fontes de luz associadas a géis clareadores de menor concentração não melhoram o resultado estético, porém há um aumento considerável da temperatura, maior no LED Azul que no violeta.

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  • IPEN-DOC 29206

    CARAMEL-JUVINO, A. ; FONTES-OLIVEIRA, Y.R. ; AVELINO, S.G. ; ZEZELL, D.M. . Avaliação da desmineralização superficial do esmalte tratado com flúor e laser utilizando Microscopia Eletrônica de Varredura. Brazilian Oral Research, v. 36, suppl 1, p. 297-297, 2022.

    Abstract: Avaliar o efeito da aplicação tópica de flúor (12.300 μF-/g) associada a irradiação com laser de Nd:YAG (84 J/cm2) na desmineralização superficial do esmalte, utilizando imagens de Microscopia Eletrônica de Varredura (MEV). Utilizou-se 60 amostras de esmalte humano (CAAE: 02854118.3.0000.0075), divididas em 4 grupos: Controle Negativo, Flúor, Laser e Flúor + Laser (n=15). Após os tratamentos, os grupos foram subdivididos em 3 (n=5), para ciclagem de pH in vitro simulando três condições diferentes: pH 5 (abaixo do pH crítico do esmalte), pH 4,5 (abaixo do pH crítico do esmalte na presença do flúor) e pH 4 (investigativo). Quatro imagens por amostras foram obtidas por MEV a 15 kV, em aumento de 4.000X. As imagens foram classificadas como esmalte hígido, desmineralização leve, moderada ou severa. Para análise estatística, realizou-se uma normalização, onde a classificação de desmineralização severa foi equiparada a 100% de desmineralização, 0 foi equiparado à classificação saudável e as demais classificações foram proporcionais. Em pH 5, os grupos Flúor, Laser e Flúor + Laser não tiveram diferenças significativas entre si (p>0,05). Em pH 4,5, o grupo Flúor + Laser teve o menor percentual de desmineralização (p<0,05). Já em pH 4, não houve diferença significativa entre nenhum grupo. Os dados sugerem que o tratamento de Flúor + Laser tem ação preventiva mesmo em pH abaixo do crítico para esmalte na presença do flúor (pH 4,5). Além disso, indica que possivelmente este tratamento altera o pH crítico da estrutura para valores entre 4,5 e 4, ampliando o poder preventivo do flúor.

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  • IPEN-DOC 29205

    MENDES, V. ; AZEVEDO, L.H. ; ZEZELL, D.M. . High-intensity non-ablative lasers in sleep-disordered breathing. Brazilian Oral Research, v. 36, suppl 1, p. 245-245, 2022.

    Abstract: Primary snoring and severe apnea are considered sleep-disordered breathing and represent different degrees of severity of the same disorder which affects around one billion people worldwide. It is more common in men and the elderly. The noise is caused by the soft tissues's vibration in the regions of greatest constriction of the upper airways. Increased cardiovascular risk, emergence of chronic diseases and use of medications are due to the progression and evolution of the disease. After determining optimal irradiation conditions, this study aimed to evaluate the treatment of snoring with sequential high-intensity non-ablative irradiation with two pulsed lasers Nd:YAG and Er:YAG comparing the results before and after treatment. A randomized, double-blind, controlled clinical trial is underway with the approval of the research ethics committee. To date, 32 of 40 volunteers transitioning between primary snoring and moderate obstructive sleep apnea have been treated in three sessions of nonablative laser irradiation, 14 days apart. The volume of the oropharyngeal space for air passage was analyzed by photographic record according to the modified Mallampati index. Oxygen saturation, snoring severity and sleep quality will also be evaluated. The primary clinical outcome obtained was the expansion of the upper airway lumen by reducing tissue compliance and, therefore, reducing or eliminating snoring, in an outpatient procedure. The reduction of snoring is due to the decrease in tissue compliance.

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  • IPEN-DOC 29204

    SARDO, A.V.N. ; CORRÊA, L. ; PRADO, F.C.R. ; FIGUEIREDO, A. ; ANDRADE, M.F. ; ZEZELL, D.M. . Avaliação da área epitelial marcada com CK 10 e CK 14 após fotobiomodulação em mucosite oral induzida por radiação gama. Brazilian Oral Research, v. 36, suppl 1, p. 143-143, 2022.

    Abstract: A mucosite oral (MO) decorre de tratamento quimoterápico e/ou radioterapico em cabeça e pescoço, podendo gerar úlceras que predispõem o paciente a quadros infecciosos e álgicos. A fotobiomodulação (PBM) com laser de baixa intensidade vem sendo destaque nos últimos anos, com bons resultados clínicos. Poucos trabalhos descrevem a ação da PBM na MO em relação ao amadurecimento epitelial. As citoqueratinas 10 e 14 (CK10 e CK14) são exemplos de proteínas que podem auxiliar este raciocínio, sendo a CK 10 característica de queratinócitos com maior grau de diferenciação e a CK14 de queratinócitos em camadas menos diferenciadas. Este trabalho avaliou a extensão da área epitelial marcada por meio de imunohistoquímica, positiva para CK10 e CK14, em MO radioinduzida em língua de ratos e tratada por PBM com laser 660 nm e 789 nm, comparados com grupo não tratado. As amostras foram coletadas nos dias 8 e 20 após a sessão de irradiação. A área expressando CK10 foi estatisticamente maior no grupo tratado com laser vermelho no vigésimo dia do experimento em relação aos demais grupos. Para a CK 14, não houve diferença estatística na quantidade de área marcada, mas sim na distribuição da marcação desta proteína pelo epitélio, que nos grupos tratados com PBM encontrava-se restrita a camada basal e no grupo controle encontrava-se também marcada em camadas mais superiores do epitélio. Conclui-se que a PBM no tratamento de MO com laser 660 nm aumentou a marcação de CK10 e, para ambos os comprimentos de onda, restringiu a marcação da CK14 a extratos basais de epitélio, como é esperado em epitélios normais.

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  • IPEN-DOC 29090

    SELLERA, FABIO P.; SABINO, CAETANO P.; NUNEZ, SILVIA C.; RIBEIRO, MARTHA S. . Clinical acceptance of antimicrobial photodynamic therapy in the age of WHO global priority pathogens: so what we need to move forward?. Photodiagnosis and Photodynamic Therapy, v. 40, p. 1-3, 2022. DOI: 10.1016/j.pdpdt.2022.103158

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  • IPEN-DOC 29055

    PINTO, ANDREIA A.G.; NAGAI, MIRIAN Y. de O.; COIMBRA, EDNAR N.; MOHAMMAD, SUHAM N. ; SILVA, JEFFERSON S.; VON ANCKEN, ADALBERTO; PINTO, SANDRA A.G.; AGUIAR, MICHELLE S.; DUTRA-CORREA, MARISTELA; HORTELLANI, MARCOS A. ; MIRANDA, ADRIANA ; SARKIS, JORGE E. de S. ; SUFFREDINI, IVANA B.; PERES, GIOVANI B.; BERNARDI, MARIA M.; CARTWRIGHT, STEVEN J.; BONAMIN, LEONI V.. Mercury chloride toxicity attenuation of the Brine Shrimp Artemia Salina after treatment with Mercurius corrosivus as isotherapic. International Journal of High Dilution Research, v. 21, n. 2, p. 6-6, 2022. DOI: 10.51910/ijhdr.v21i2.1211

    Abstract: Isotherapics prepared from toxic substances have been described as attenuation factors for heavy metal intoxication in aquatic animals. Herein, Artemia salina and mercury chloride were used as a model to identify treatment-related bioresilience. The aim was to describe the effects of Mercurius corrosivus (MC) in different potencies on Artemia salina cyst hatching and on mercury bioavailability. Artemia salina cysts were exposed to 5.0 µg/mL of mercury chloride during the hatching phase. MC 6cH, 30cH, and 200cH were prepared and poured into artificial seawater. Different controls were used (nonchallenged cysts and challenged cysts treated with water, succussed water, and Ethilicum 1cH). Four series of nine experiments were performed for 4 weeks to evaluate the percentage of cyst hatching considering all moon phases. Soluble total mercury (THg) levels and precipitated mercury content were also evaluated. Solvatochromic dyes were used to check for eventual physicochemical markers of MC biological activity. Two-way analysis of variance (ANOVA) with mixed models was used for evaluating the effect of different treatments and the simultaneous influence of the moon phases on the cysts hatching rate, at both observation times (24 and 48 hours). When necessary, outliers were removed, using the Tukey criterion. The level of significance α was set at 5%. Significant delay (p<0.0001) in cyst hatching was observed after treatment with MC 30cH, compared with the controls. An increase in THg concentration in seawater (p<0.0018) and of chlorine/oxygen ratio (p<0.0001) in suspended micro-aggregates was also seen, with possible relation with mercury bioavailability. Specific interaction of MC 30cH with the solvatochromic dye ET33 (p<0.0017) was found. The other observed potencies of Mercurius corrosivus 6 and 200 cH were not significant in relation to the observed groups. The results were postulated as being protective effects of MC 30cH on Artemia salina, by improving its bioresilience.

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  • IPEN-DOC 29043

    BIANCOLLI, ANA L.G. ; BARBOSA, ANDREY S. ; KODAMA, YASKO ; REY, JOSE F.Q.; FONSECA, FABIO C. ; SANTIAGO, ELISABETE I. . The influence of pre-irradiation and simultaneous grafting methods on the physicochemical properties of polyethylene-based anion-exchange membranes and ionomers. ECS Meeting Abstracts, v. MA2022-01, n. 35, 2022. DOI: 10.1149/MA2022-01351499mtgabs

    Abstract: Controlling the synthesis parameters during radiation-induced grafting (RIG) is a key feature to design anion-exchange membranes (AEMs) with enhanced properties that lead to high performances and stability. The present study provides a systematic investigation of the effect of RIG methods on physicochemical properties of LDPE-based AEMs with similar degree of grafting (DoG) and ion exchange capacity (IEC). The LDPE films were grafted with 4-vinylbenzyl chloride using two methods: i) pre-irradiation (PIM), using electron-beam (EB), and ii) simultaneous (SM), using gamma-ray (γ), both in air atmosphere and with different absorbed doses. The AEMs grafted by SM were irradiated with 20, 25, and 30 kGy, while the ones grafted by PIM were irradiated with doses of 30, 70, and 100 kGy. Samples grafted by the two different methods have the same molecular structure, but distinct physicochemical properties due to markedly differences in the degree of crosslinking. The studies have shown that grafting step directly influences the internal structure and morphology of AEMs. Multi-technique characterization demonstrated that RIG method determines the mechanical properties, water transport, and the distribution of ionic groups in AEMs. These characteristics have direct impact on fuel cell performance, anion-conductivity, and AEM stability. Figure 1 shows the polarization curves of anion-exchange membrane fuel cells (AEMFCs) operating at 80 °C with AEMs grafted by PIM and SM. Comparing AEMFCs performances containing AEMs with similar IECs from the two different grafting methods, it is possible to notice that AEMs synthesized by PIM, in general, promote better fuel cell performances than the corresponding ones prepared by SM. The main differences in the polarization curves are evidenced in the ohmic and the mass transport limiting regions. This result suggests that water management is enhanced in AEMs synthesized by PIM compared to the SM-AEMs. A membrane that allows rapid back diffusion of liquid water from the anode to the cathode, should reduce the current losses due to mass transport limitations. The gel content results confirmed the presence of more crosslinking in membranes synthesized by PIM than in the ones synthesized by the SM. As a consequence of that, enhanced mechanical properties were found for PIM-AEMs, indicating polymer backbone reinforcement due to high degree of crosslinking. Small-angle X-ray scattering measurements have confirmed that the microstructure of PIM and SM AEMs are different and this feature is directly related to ion conduction and water transportation. Figure 1. AEMFCs performances at 80 °C with LDPE-based AEMs grafted by the pre-irradiation method and by the simultaneous method. H2 anode gas flow=0.8 L min-1, O2 cathode gas flow=0.5 L min-1, both supplied unpressurized with optimal dewpoint temperatures ranging from 77 to 80 °C. AEMs are referred according to the grafting method and absorbed dose. 30 and 70-EB-PIM refer to the samples irradiated with 30 and 70 kGy, respectively, in the EB accelerator and grafted by the pre-irradiation method. 20 and 25-γ-SM refer to AEMs irradiated with 20 and 25 kGy, respectively, by γ-rays and grafted by the simultaneous method.

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  • IPEN-DOC 28989

    ROCHA, R.M.M. ; MENDES, F.M. ; ZEZELL, D.M. . Efeitos do filme PVC na performance do DIAGNOdent em lesões de cárie oclusal em dentes decíduos. Brazilian Oral Research, v. 18, Supplement, p. 240-240, 2004.

    Abstract: O objetivo deste trabalho foi avaliar a influência da utilização do filme PVC, como barreira de proteção, na performance do DIAGNOdent (DD) em lesões de cárie oclusal em dentes decíduos. Foram utilizados 21 molares decíduos que foram avaliados em 5 diferentes condições: (1) DD calibrado sem filme PVC na ponteira, (2) DD calibrado com uma camada de filme PVC e as amostras analisadas, (3) DD calibrado com 3 camadas de filme PVC e as amostras analisadas, (4) DD calibrado sem filme PVC e as amostras mensuradas com o DD com uma camada do filme, (5) DD calibrado sem filme PVC e as amostras mensuradas com o DD com 3 camadas do filme. A validação histológica foi feita por meio de lupa. Foi realizada ANOVA e teste de Tukey para comparação entre os valores obtidos em cada grupo. A área sob a curva ROC para lesões em dentina foi calculada e comparada entre os grupos. Usando o ponto de corte de 13, foi calculada a acurácia (teste de McNemar para comparação). Houve diferença significante entre os valores de medição (p < 0,05) entre os grupos 1 e 5; 1 e 3; 2 e 5. Obteve-se acurácia de 0,81 para os grupos 1, 2 e 3 e de 0,73 e 0,71 para os grupos 4 e 5, respectivamente, mas não houve diferença significante entre esses valores. A área sob a curva ROC mostrou diferença estatisticamente significante entre os grupos 2 e 4. Concluiu-se que, para melhor desempenho do DD, a ponteira do equipamento deve ser calibrada na mesma condição em que se pretende analisar as lesões. Condições que utilizam 3 camadas de PVC devem ser evitadas, para que não se subestime lesões de cárie em situações clínicas.

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  • IPEN-DOC 28988

    ANA, P.A. ; BLAY, A. ; TURBINO, M.L. ; ZEZELL, D.M. . Análise de microdureza de esmalte irradiado com laser Er,Cr:YSGG em baixas fluências. Brazilian Oral Research, v. 18, Supplement, p. 235-235, 2004.

    Abstract: As modificações nas propriedades químicas do esmalte irradiado provocadas por laser podem indicar o uso deste tratamento como um mecanismo para prevenção da cárie. Este estudo in vitro objetivou avaliar o efeito da irradiação do laser Er,Cr:YSGG em baixas fluências na microdureza do esmalte. Quinze blocos de esmalte foram obtidos de dentes terceiros molares humanos recém-extraídos. As amostras foram embutidas em resina acrílica e foram seccionadas transversalmente em duas porções, sendo uma parte irradiada e outra mantida como controle. Após o polimento, as amostras foram divididas em três grupos e irradiadas de acordo com as seguintes fluências: 2,8 J/cm2 (12,5 mJ/pulso), 5,6 J/cm2 (25 mJ/pulso), e 8,5 J/cm2 (37,5 mJ/pulso). As irradiações foram realizadas com taxa de repetição de 20 Hz, com ausência de spray ar-água e sob a forma de varredura. As superfícies seccionadas das amostras foram submetidas à análise de microdureza Vickers, realizando-se vinte indentações por amostra. Os resultados foram convertidos em porcentagens e submetidos à análise de variância, com p < 0,05. Os resultados mostraram que a microdureza do esmalte dental foi significativamente aumentada nas amostras irradiadas em comparação com as não-irradiadas e as mudanças obtidas foram dependentes das fluências utilizadas. A irradiação com laser Er,Cr:YSGG em baixas fluências pode aumentar a microdureza superficial do esmalte, o que pode indicar um aumento na sua resistência ácida. Conseqüentemente, o laser Er,Cr:YSGG tem potencial para ser utilizado na prevenção da cárie.

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  • IPEN-DOC 28987

    ANA, P.A. ; ROCHA, R.M.M. ; BLAY, A. ; AUN, C.E.; LAGE-MARQUES, J.L. ; ZEZELL, D.M. . Estudo morfológico da superfície de canais radiculares irradiados com laser Er,Cr:YSGG. Brazilian Oral Research, v. 18, Supplement, p. 164-164, 2004.

    Abstract: O objetivo deste estudo foi avaliar a aparência de canais irradiados com laser de Er,Cr:YSGG após preparo do canal radicular. Selecionou-se nove dentes unirradiculares humanos, cujos canais receberam preparo endodôntico com limas tipo K, associado ao Endo PTC e solução de Dakin. As amostras foram irrigadas com solução desmineralizante EDTA-T por 5 minutos e divididas em 4 grupos. As amostras do grupo I não foram irradiadas, enquanto as do grupo II, III e IV foram irradiadas em associação com a solução irrigadora, utilizando as seguintes fluências: GII (12,5 mJ/pulso; 2,8 J/cm²), GIII (25 mJ/pulso; 8,5 J/cm²) e GIV (75 mJ/pulso; 16,98 J/cm²). A irradiação laser foi realizada com frequência de 20 Hz e ausência de spray ar-água. As superfícies irradiadas foram, então, observadas em microscopia eletrônica de varredura (MEV). Observou-se que as áreas irradiadas apresentaram discreta ablação que aumentava com o aumento da fluência do laser. Não foram encontradas diferenças significativas nos terços coronais das amostras irradiadas ou não irradiadas correspondentes ao padrão de superfície e presença de “smear layer”. No terço médio, as amostras irradiadas apresentaram túbulos abertos e menor quantidade de “smear layer”; no terço apical, as amostras irradiadas exibiram túbulos parcialmente abertos e fina camada de magma dentinário. Conclui-se que a irradiação de canais radiculares com laser Er,Cr:YSGG remove a “smear layer” e propicia a abertura dos túbulos dentinários, o que pode melhorar a permeabilidade dos canais radiculares e por sua vez a ação de protocolos terapêuticos.

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  • IPEN-DOC 28976

    SILVA, MARIA E. da C. ; RODRIGUES, RENATA B. ; ULIAN, ANDRESSA A.. Revisão das propriedades metabólicas do Bacillus subtilis e suas aplicações biotecnológicas favoráveis à biocenose. Revista Multidisciplinar em Saúde, v. 2, n. 2, 2021. DOI: 10.51161/rems/1157

    Abstract: Introdução: O gênero Bacillus é considerado um grupo altamente heterogêneo de bactérias, catalogadas em 268 diferentes tipos de espécies e 7 subespécies, tem formato de bastonete e pertence a família Bacilaceae. Ações dessa bactéria não se limitam à promoção da saúde humana, se estendem a macro benefícios no ecossistema e, a consolida como ferramenta no combate ao desequilíbrio ambiental. Mediante os expressivos benefícios, algumas espécies se tornaram foco de relevantes estudos, como o Bacillus subtilis. Essa espécie possui características categóricas, como, pertencem as rizobactérias Gram-positivas e promotoras de crescimento de plantas, termófila, saprófita, produz catalase positiva, não patogênica e capaz de realizar esporulação para manutenção de sua demanda metabólica e inibe a esporulação de fungos. Além disso, sintetiza biossurfactantes e antibióticos com diversas aplicabilidades biotecnológicas, principalmente na biorremediação de solos e água contaminados. O B. subtilis expressa algumas características antimicrobianas, incluindo antifúngicas, e até mesmo nematicidas, esta última característica foi a menos subestimada, considerando as aplicações de tratamento para doenças de nematoides. Enfatizando a produção dos diversos antibióticos, entre eles, lantibióticos e outros, gerados de forma não ribossômica, outras substâncias secundárias, como os compostos policetídeos com propriedade farmacológica, conhecida popularmente por claritromicina e azitromicina. Um exemplo de antibiótico polipeptídico produzido pelo B.subtilis é a bacitracina. Objetivo: Elucidar a ação antimicrobiana e biossurfactantes do B.subtilis, caracterizando-as como propriedades singulares de seu metabolismo que contribuem na síntese de produtos biotecnológicos sem acometer o meio ambiente. Metodologia: Revisão bibliográfica sistemática em sites como: Pubmed, scielo e sciencedirect, utilizando os descritores: “Bacillus subtilis”, “biossurfactantes” e “antimicrobianos”. Resultados: Através da revisão literária foi possível observar um padrão das informações a respeito do Bacillus subtilis que foram tanto como estáveis em suas relações como de suas causalidades, gerando uma nova visão à biotecnologia a favor da vida. Conclusão: Partindo da premissa de que o B.subtilis é uma espécie promotora do equilíbrio da biocenose, essa revisão possibilitou unir informações à nova perspectiva da capacidade promotora do seus metabólitos, principalmente os biossurfactantes e os antimicrobianos que possuem inúmeras aplicabilidades biotecnológica e, a sua coexistência para o fazer o bem à biocenose.

    Palavras-Chave: bacteria; bacillus subtilis; biotechnology; metabolites; ecosystems

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  • IPEN-DOC 28881

    SILVA, FABIO A. da ; BERNARDES, EMERSON S. . Uncovering the role of modified citrus pectin in cancer. Nuclear Medicine and Biology, v. 108-109, S1, p. S176-S177, 2022. DOI: 10.1016/S0969-8051(22)00371-7

    Abstract: Background: Modified citrus pectin (MCP) is a polysaccharide consisting of galacturonic acid with anti-cancer activity that can act synergistically with other treatments to reduce tumor growth, stimulate programmed cell death and reduce the number of metastases. In addition, MCP prevents acute and severe renal syndromes caused by radiation/chemotherapy. All of these effects were reported to be due to MCP ability to specifically inhibit Galectin-3 protein functions. Aims: The aim of this work was to evaluate the anticancer effect of MCP in a Balb/c nude mice xenograft model of ovarian cancer. Methods: The human ovary cancer cell line, SKOV-3, was subcutaneously injected in Balb/c nude mice and tumor growth was monitored daily with a caliper. When tumors reached 250-300 mm3, 20 mg/kl of MCP was administered intravenously (I.V.) in a daily based for 21 days. Tumor growth and mice weight were monitored daily. Additionally, MCP was radiolabeled with 99m-technetium (99m-Tc) with the incubation of MCP (2.5 mg) in saline with SnCl2 (4 mg/ ml), HCl (0.01 M), NaOH (0.01 M) and 99mTc (129,5 MBq) at pH=7 for 30 min. The radiochemical purity was determined by iTLC-SG with acetone and ethanol/NH3/H2O (1:2:5). 99mTc-MCP (37 MBq) was administrated I.V. in Balb/C nude mice bearing SKOV-3 tumors and after 1, 2 and 4 hours, SPECT/CT image was acquired (Albira SI Buker). Ex-vivo biodistribution studies were performed after the I.V. injection of 10 MBq of 99mTc-MCP for 1-hour. The % of injected dose per gram (%ID/g) of tissues of interest was calculated. The tumors were removed, fixed, cut and used for autoradiography studies and stained with hematoxylin and eosin (H&E) to verify hypoxic regions. Results: The I.V. administration of MCP was able to significantly reduce SKOV-3 tumor growth (52% tumor volume reduction) in comparison with the non-treated group, after 21 of treatment. Our biodistribution studies showed that 99mTc-MCP was mainly found in kidneys, bladder and liver of mice (%ID/g = 12.25, 38.57 and 5.71, respectively), and was able to reach the tumor (%ID/g = 0.765 ± 0.045) 1-hour after I.V. administration. 99mTc-MCP accumulation in the tumor site was visualized by μSPECT/CT imaging 1 hour after I.V. administration. The autoradiography and stained (H&E) study demonstrated a correlation between MCP and regions of tumor necrosis. Because of MCP high accumulation in kidneys, renal toxicity was also evaluated. We were able to find that MCP doesn’t induce renal toxicity when administered in a daily base at a concentration of 20 mg/Kg. Conclusion: In this work we demonstrated that a daily treatment of MCP was able to reduce tumor growth of ovarian tumor xenografts (SKOV-3 cells) without showing renal toxicity. We found too that MCP can reach the tumor site, binding mainly in regions of necrosis. However, other studies are needed to unravel the mechanisms of action that act on the antitumor effect of MCP.

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  • IPEN-DOC 28695

    GIMILIANI, GIOVANA T. ; IZAR, GABRIEL. Difficulties in comparison among different microplastic studies: the inconsistency of results and lack of guide values. Environmental Toxicology and Chemistry, v. 41, n. 4, p. 820-821, 2022. DOI: 10.1002/etc.5237

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  • IPEN-DOC 28620

    ZEZELL, DENISE M. . Radiation Technology in Health Sciences at IPEN: a multidisciplinary and interdisciplinary Professional Master Degree. Biophysical Reviews, v. 13, n. 6, p. 1531-1531, 2021. DOI: 10.1007/s12551-021-00844-3

    Abstract: INTRODUCTION The Professional Master Program in Radiation Technology in Health Sciences (MP-TRCS) of the Nuclear and Energy Research Institute- IPEN/CNEN is a new program, started in August 2019. It is the only graduation program in the country to offer two nuclear reactors for educational purposes, for the development of dissertations, in addition to providing radiopharmaceuticals production in a nuclear reactor, in linear accelerator for radioisotope production, as well light and lasers applications. In addition to the infrastructure, the program has multidisciplinary training advisors working in an interdisciplinary manner who use their vast experience in radiation applied to medicine to guide students in a productive manner with a high degree of excellence. OBJECTIVES The MP-TRCS aims to fulfil a growing demand at IPEN/ CNEN from professionals working in hospitals and clinics, using ionizing and non-ionizing radiation. MATERIALS AND METHODS These students need a more dynamic course directed to the practical professional activities. We have students from the most diverse areas, such as medical doctors, biomedical doctors working in clinical analyses, radiotherapy physicists, physiotherapists, dentists specializing in imaging diagnosis and laser, among others, participating in the front line, who use radiation or assess its impact on their day-today routine. DISCUSSION AND RESULTS The first students have already begin to present their dissertation. The employability has increased among students enrolled in the program. CONCLUSION These professionals bring their experience to the program, which together with IPEN's academic structure and advisors, result in skilled students who are finding numerous career opportunities in the job market.

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  • IPEN-DOC 28619

    VIEIRA, DANIEL P. . Three-dimensional cellular culture system for testing of biological effects of radiations in tumoral and non-tumoral models. Biophysical Reviews, v. 13, n. 6, p. 1521-1521, 2021. DOI: 10.1007/s12551-021-00844-3

    Abstract: In vitro cell cultures are a well-known controlled test system used to analyze tumor physiologic responses upon negative stimuli. Updated techniques, us-ing three-dimensional organization of cells in cultures, are being increasingly used to this purpose. Research organizations and industry are striving to pro-duce in vitro tumor surrogates that could be better test systems to antitumor agents as new compounds or to study radiation effects on cancers. The presentation will show some techniques currently used to build and maintain these specific cell cultures, and how experiments are evolving towards the production of tumoroids, or tumoral organoids, which will include various cell types and additive manufacturing.

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  • IPEN-DOC 28618

    DEL MASTRO, NELIDA L. ; GERVASONI, J.L.. Women in the nuclear field promoting Latin American integration. Biophysical Reviews, v. 13, n. 6, p. 1517-1517, 2021. DOI: 10.1007/s12551-021-00844-3

    Abstract: Nuclear energy is used for the generation of electricity, but also for the production of radioisotopes, desalination of sea water and also for the production of hydrogen. Activities in the nuclear field are in the area of science, technology and innovation that has long belonged to an essentially male domain, in which the contributions of women were neglected or underestimated. The central idea for the creation of Women in Nuclear, WiN Global, was to support and encourage women working in nuclear science and technology and encourage the promotion of understanding and knowledge of the benefits of the peaceful use of nuclear energy by the public. WiN Global currently has predominantly female members coming from 129 different countries, belonging to chapters or individually. Today, WiN Global is integrated by 53 WiN Global chapters. Forty-nine countries have their own chapters and there are also regional and international ones. The history of Latin American integration started during the political independence movement of the countries of the New Continent. Since then, up and downs were overcome in order to keep a regional ambiance of good relationship. In the present study, a new form of integration is presented by the efforts of the women working in the nuclear ambit. This important movement involves Latin American WiN chapters (such as WiN Argentina, WiN Brazil, WiN ARCAL) promoting activities for the integration of our region. In order to quantify, to some extent, the participation of Latin American women, this paper presents a survey crossing data of the number of related publications to help to address an objective analysis of the trend of this integration.

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  • IPEN-DOC 28617

    YOSHIMURA, TANIA M. ; SAUTER, ISMAEL P. ; RIBEIRO, MARTHA S. . Low power light triggers opposite effects on stem cells: influence of the wavelength and culture conditions. Biophysical Reviews, v. 13, n. 6, p. 1492-1493, 2021. DOI: 10.1007/s12551-021-00844-3

    Abstract: INTRODUCTION Photobiomodulation (PBM) has been gaining importance in a wide range of medical fields in the past few years, particularly in stem cell-based regenerative medicine. Improving in vitro cell proliferation, differentiation and viability are ways where PBM could play a pivotal role optimizing biotechnological and bioengineering applications. OBJECTIVES Here we investigated whether different wavelengths (blue, green and red) would promote distinct outcomes in human adipose-derived stem cells (hADSCs) cultured in regular and supplemented media for tenocyte differentiation. MATERIALS AND METHODS Freshly isolated hADSCs were cultured in a specific stem cell medium (MSCGM, Lonza), DMEM or a tenogenic medium (TEN-M: DMEM supplemented with growth factors and ascorbic acid). Cells were irradiated every 48 h (23.28 mW/cm 2 , 17 min 10 s delivering 24 J/cm 2 per session) using a LED irradiator (LEDbox, BioLambda). MTT and crystal violet assays were used to evaluate cell metabolic activity and proliferation. DISCUSSION AND RESULTS Red wavelength (660 nm) significantly increased metabolic activity after five irradiations, but only for cells cultured in TEN-M. Oppositely, blue (450 nm) and green (520 nm) light decreased both cell proliferation and metabolic rate, with more pronounced effects for blue light in TEN-M. Considering these findings, we examined whether irradiating only the media would generate toxic compounds that could impair cell viability. We therefore assessed reactive oxygen species (ROS) production by p-nitrosodimethylaniline/histidine assay while irradiating the three different media under the same conditions as mentioned above. Immediately after blue and green light exposure, an increment in ROS production was observed for DMEM and TEN-M, that continuously increased until reaching between 4.5 and 7.1 μM one-hour after irradiation – with higher values for TEN-M exposed to blue light. CONCLUSION Since no significant ROS formation was observed following red light exposure, we concluded that medium composition was responsible for the different effects on metabolic activity and proliferation observed after irradiation with different wavelengths.

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  • IPEN-DOC 28616

    RIBEIRO, MARTHA S. . Light-based non-thermal therapy: from basis to clinical applications. Biophysical Reviews, v. 13, n. 6, p. 1491-1491, 2021. DOI: 10.1007/s12551-021-00844-3

    Abstract: Light-based non-thermal therapies are evolving as promising non-invasive and cost-effective medical technologies. These therapeutic platforms mainly encompass photobiomodulation (PBM) and photodynamic therapy (PDT), which use visible or near infrared (NIR) light to induce biological responses without any significant heating effects. For PBM, it is most commonly used red or NIR light to optimize light penetration into biological tissues. The photon absorption by natural chromophores at these spectral regions cause photophysical and photochemical reactions inside cells that trigger several biological effects such as to accelerate wound healing, reduce inflammation and relief pain, depending on light parameters and target tissue. On the other hand, PDT makes use of photoactivated drugs, also called as photosensitizers, which absorb light to induce chemical reactions that kill microbial or cancer cells by oxidative stress. Our group have been investigating the mechanisms and several applications of PBM and antimicrobial PDT (APDT) for almost 20 years. In this lecture I will share our experience in the area to discuss how PBM and APDT could be used to revolutionize health care in the photonics era. An integrated perspective from the basic mechanisms, preclinical and clinical trials for both therapies will be presented, including PBM on cancer management and APDT against drug-resistant pathogens. The lecture will also highlight future perspectives.

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  • IPEN-DOC 28615

    LIMA, MAYELLE M.P. ; NASCIMENTO, PAMELA F. do ; NASCIMENTO, ANA C.G. ; VIEIRA, DANIEL P. . A simple and quick method to generate in vitro tridimensional tumor bodies from a human breast adenocarcinoma (MCF7) using magnetic aggregation technique. Biophysical Reviews, v. 13, n. 6, p. 1470-1470, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Tumor physiology studies have to rely on efficient and representative models, as animal-based or in vitro tridimensional cell constructs. The work used magnetite (Fe3O4) nanoparticles produced by electron-beam induced chemical reduction to give cells the ability to form aggregates when submitted to a magnetic field, and thus to produce micro tumors in vitro. OBJECTIVES The work aimed to produce human breast adenocarcinoma mini tumors (BAMT's) in vitro. MATERIALS AND METHODS Paramagnetic iron oxide nanoparticles (PION’s) were synthesized through electron-beam induced Fe3+ reduction and subsequent coprecipitation. Due to its poly-L-lysine coating, PION’s were adsorbed on cell membranes ofMCF7 (human breast adenocarcinoma). Cells were seeded in 24-well cell culture plates pre-treated overnight with Pluronic® F-127 to prevent cell adhesion and kept in culture conditions under magnetic fields for at least 6 days. BAMT's were differentially stained with Hoescht 33342 and ethidium bromide and imaged by wide-field fluorescence microscopy. DISCUSSION AND RESULTS BAMT's appeared as integer and well-defined cellular aggregates, with sparse dead cells stained by ethidium bromide. These structures can be further used for in vitro tumor studies, as BAMT’s are supposed to be more reliable models than monolayer cultures. Treatment of wells with poloxamer caused a mild to moderated cell-repellent effect, similar to those found in commercially available products, only by a fraction of the cost. CONCLUSION The experiments succesfully produced mini tumors prone to be used in in vitro studies.

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  • IPEN-DOC 28614

    SANTOS, CAROLINA S.F. dos ; BELLINI, MARIA H. ; SANTOS, SOFIA N. dos ; ARAUJO, ELAINE B. de . Estudo sobre a eficiência do radiofármaco PSMA-1007-18F na detecção do câncer de próstata em um estudo pré-clínico in vivo. Biophysical Reviews, v. 13, n. 6, p. 1467-1467, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION O PSMA-1007-18F é caracterizado por uma biodistribuição única em comparação com outros agentes de PSMA, pois é eliminado através do fígado, além de ter captação elevada dentro das células do câncer de próstata. OBJECTIVES O objetivo deste trabalho é analisar a especificidade do radiofármaco PSMA-1007-18F em camundongos com modelo tumoral PSMA+ através de um estudo de bloqueio. MATERIALS AND METHODS Animais SCID com células tumorais LNCaP foram preparados e divididos em quatro grupos (n=5) de acordo com os tempos de biodistribuição de 30 minutos, uma hora, duas horas e uma hora com agente bloqueador PSMA I&T (100μg/μL), sendo injetado 30 minutos antes do radiofármaco. Foram injetados 5,55 MBq (0,056 MBq/μL) via caudal nos animais e após os tempos pré-determinados foram sacrificados, com os órgãos de interesse coletados, pesados e sua atividade contabilizada. As imagens PET/CT foram realizados para ilustrar a captação do PSMA-1007-18F pelo tumor e por órgãos PSMA+ com e sem bloqueio. DISCUSSION AND RESULTS O grupo de 30 minutos apresentou maiores captações, caracterizando o estágio de distribuição. Rins e baço apresentaram alta captação pelo PSMA-1007-18F por serem PSMA+, onde sua especificidade pode ser constata pela drástica diminuição de captação nos animais com agente bloqueador. A captação pelas células tumorais de próstata se mostrou constante durante o período avaliado e foi efetivamente bloqueada pelo excesso de PSMA I&T (imagem), que confirma a ligação do radiofármaco aos receptores de PSMA. Apesar de apresentar uma baixa hidrofilicidade, a razão entre tumor/sangue e tumor/músculo foi de 14,18 ± 3,19 e 4,78 ± 1,52 em 1h, respectivamente. CONCLUSION O radiofármaco PSMA-1007-18F apresenta propriedades de ligação que fornecem captação tumoral específica. Sua viabilidade em imagens para câncer de próstata foi demonstrada pela alta especificidade pelas células PSMA+ e pela via de excreção hepatobiliar. Os resultados deste estudo serão úteis para subsidiar o registro e comercialização deste radiofármaco.

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  • IPEN-DOC 28613

    NASCIMENTO, ANA C.G. ; GALISTEO JUNIOR, ANDRES J.; SILVA, GIOVANA D. da ; ROCHA, LEONARDO W.P. de S. ; VIEIRA, DANIEL P. . Effective methodology for maintaining Toxoplasma gondii in vitro using paramagnetic iron nanoparticles to support three-dimensional cell culture. Biophysical Reviews, v. 13, n. 6, p. 1466-1466, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Toxoplasma gondii is a protozoan parasite that infects approximately one billion people worldwide. Upon infection, the host may die due to latent infection or presence with chronic cysts in brain, retina or muscle tissue. Humans can become infected consuming water or foods contaminated with oocysts or eating undercooked meat. Its virulent form is difficult to replicate in vitro, requiring additional steps using experimental animals. The use of nanotechnology can contribute to this in vitro production, through the three-dimensional cultivation of mouse fibroblast cells (NIH / 3T3 ATCC ® CRL-1658™) and nanoparticles synthesized with radiation. OBJECTIVES The objective of this work was to demonstrate the three-dimensional culture of fibroblast cells aggregated to nanoparticles for inoculation the T. gondii. MATERIALS AND METHODS This methodology was created to facilitate parasite management and replication. For the production of nanoparticles, the work used concentrations of iron sulfate II heptahydrate (Fe2SO4.7H2O, CAS 7782-63-0) and glycine (NH2CH2COOH, CAS 56-40-6) diluted in ultrapure water free ofO2 at pH 12. This solutionwas irradiated by electron beam of the IPEN / CNEN-SP Radiation Technology Center in doses of at least 15 and at most 30kGy. Paramagnetic iron oxide nanoparticles (PION’s) were then adsorbed on cell membranes, and cells were kept together by a magnetic field. Structured spheroids (4 day of culture) were infected with 106 parasites (RH strain) and the infection was evaluated by transmission electron microscopy. DISCUSSION AND RESULTS Tachyzoiteswere found inside 3T3 cells, assuring that the spheroid can be a suitable culture substrate to T. gondii in vitro propagation. CONCLUSION A three-dimensionalmethodology for in vitro cultivation of the parasite is perhaps the key for applications in the study of toxoplasmosis, as it has a fast, cheap, efficient production (yield and reduction of contamination).

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  • IPEN-DOC 28612

    SEPULVEDA, ANDERSON F.; FRANCO, MARGARETH ; YOKAICHIYA, FABIANO; ARAUJO, DANIELE de. POLYana: a new software for rheological study of polymeric colloidal materials. Biophysical Reviews, v. 13, n. 6, p. 1464-1465, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION POLYAna is a new executable software developed by SISLIBIO group for rheological analysis of hydrogel and organogel systems and other colloidal materials (nanoparticles and micelles). The software development aims to facilitate the analysis of rheology data associated to both temperature- and frequency-dependent analysis, viscosity and curve flow profiles. OBJECTIVES The software development aims to facilitate the analysis of rheology data associated to both temperature- and frequency-dependent analysis, viscosity and curve flow profiles. MATERIALS AND METHODS From raw data, several models are applied like power-law model for frequency response and curve flow, Boltzmann law to calculate gelation temperature and viscosity response under temperature,Maxwell model to study interchain relationships in addition to other models such as Bingham model, Cross model, and Herschel-Bulkley are also available. POLYana outputs calculates rheological parameters like consistency, adhesion, hysteresis, flow index, G’/G” ratio. DISCUSSION AND RESULTS To validate results obtained from POLYana, same data were analyzed by applying other programs and same mathematical models. In this sense, rheological analysis of Poloxamer 407 in water solution (15 %) were performed: from temperature-dependent G’ and G” analysis were obtained gelation temperature of 45.46 ± 0.02 °C, η_0 = 0.08 ± 0.03 mPa*s, η_max = (32.44 ± 0.17) mPa*s and dη/dT = (1.27 ± 0.02) mPa*s/°C by fitting Boltzmann law (R2 = 0.998), which are similar to results obtained by others softwares and found in literature. From temperature-dependent G’ and G” analysis, it gets adhesion value of (1647.15 ± 18.01) mPa*sn calculated from power-law model (R2 = 0.869), also similar to PRISM results. CONCLUSION Also, other Poloxamer concentrations and hydrogels types have been evaluated, showing close numbers to that previously reported. In order to stablish structural relationships, one of POLYana tools is also to analyze small-angle neutron scattering (SANS) and develop Monte Carlo simulation for SANS and rheological analysis, simultaneously.

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  • IPEN-DOC 28611

    SILVA, CAMILA R. ; PINTO, MAYARA S. ; RIBEIRO, MARTHA S. . Photodynamic therapy associated with ionizing radiation in the treatment of triple-negative breast cancer cells. Biophysical Reviews, v. 13, n. 6, p. 1386-1386, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Breast cancer is the most common cancer for women worldwide. According to the World Health Organization, it is considered the 5 th leading cause of death from cancer. Triple-negative breast cancer (TNBC) is a subtype of this disease that represents around 20% of all invasive breast cancer, whose main characteristics are resistance to conventional treatments, such as exposure to ionizing radiation (IR). On the order hand, the photodynamic therapy (PDT) using porphyrins and their derivatives has been described in the literature as a potential therapy against cancer. OBJECTIVES Thus, our goal in this work was to associate PDT and IR in the treatment of TNBC. MATERIALS AND METHODS MDA-MB-231 cells at a concentration of 2x104 cells were submitted to PDT using TMPyP porphyrin (30 μM) and a red light (660 ±11 nm) with fluences of the 23 and 57.5 J/cm 2 (57.3 mW/cm 2). Immediately post-PDT, cells were divided into groups: non-treated (control), only IR and PDT associated with IR (PDT57+IR and PDT23+IR) and then, exposed to IR with a dose of 2.5 Gy. Past 24-h of the PDT-session, the cell viability, clonogenicity and total glutathione were verified. DISCUSSION AND RESULTS Cells exposed to IR not presented statistically significance difference compared to the control group. However, treated groups showed around 38% lower cell viability in relation to the control and IR groups. For the clonogenic assay a reduction of the approximately 65% was observed between IR and treated groups. Regarding to the total glutathione, all groups showed an increase when compared to control group. Nonetheless, no were identified differences between IR and treated groups. CONCLUSION Taken together, our results indicate that PDTassociate with IR may be an ally in TNBC treatment.

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  • IPEN-DOC 28610

    PINTO, MAYARA S. ; SILVA, CAMILA R. ; SALVEGO, CAMILA de A. ; SIMOES, MARTHA R. . Red LED irradiation impacts the cytotoxic response of murine breast cancer cells to ionizing radiation. Biophysical Reviews, v. 13, n. 6, p. 1385-1385, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Breast cancer is a disease of worldwide importance since it is considered the 5th leading cause of cancer deaths. Triple-negative breast cancer (TNBC) is a molecular subtype that presents resistance to conventional radiotherapy, demanding high doses of ionizing radiation (IR) for a prolonged period of treatment. On the other hand, low-level light irradiation (LLLI) has been studied to sensitize cells before IR exposure. However, the literature is poor regarding the association of both techniques in TNBC cells. OBJECTIVES Thus, we aimed to assess the effect of LLLI before IR exposure on two TNBC cell lineages. MATERIALS AND METHODS MDA-MB-231 (human TNBC) and 4T1 (murine TNBC) were cultivated, seeded at a density of 2.5 x 10 5 cells/cm², and maintained in an incubator (37ºC, 5% of CO2) overnight. LLLI was performed with a red LED (λ= 660 ± 11 nm, 38.2 mW/cm²) delivering energies of 1.2 J and 6.0 J. One-h after LLLI, the cells were submitted to both 2.5 and 5.0 Gy doses from a 60 CO source. After 24-h, mitochondrial activity (MA) was quantified by MTT assay with n= 9/group. DISCUSSION AND RESULTS Our data showed that 4T1 cells exposed to LLLI at 1.2 J exhibited higher MA than cells exposed to IR2.5. In contrast, cells exposed to 6 J of LLLI showed lower MA than IR5. Concerning MDA-MB231 cells, no statistically significant differences were noticed among groups regardless of IR and LLLI doses. CONCLUSION These findings indicate that LLLI before IR could sensitize only murine breast cancer. Besides, an appropriate combination of IR and LLLI doses seems to play a role to kill TNBC cells.

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  • IPEN-DOC 28609

    SOUZA, MARESSA D.F. de ; ITRI, ROSANGELA; RIBEIRO, MARTHA S. . Reconstitution of Leishmania plasma membrane to understand the photodynamic effect. Biophysical Reviews, v. 13, n. 6, p. 1384-1384, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Leishmaniasis is an important neglected disease. Photodynamic therapy (PDT) has been used to fight cutaneous leishmaniasis showing good results. However, PDT mechanisms in Leishmania parasites are not yet completely clarified. OBJECTIVES In this work, our objective was to develop a protocol to produce giant plasma membrane vesicles (GPMVs) from Leishmania amazonensis promastigotes to understand the mechanisms of action of methylene blue (MB)-mediated PDT on the cell membrane of parasites. MATERIALS AND METHODS For membrane extraction, several techniques were tested. The osmotic shock was the technique that presented the best yield and effectiveness. Phosphate and protein measurements were performed to confirm membrane extraction. For the growth of GPMVs, the best technique was electroforming using different frequencies and voltages in 4 cycles. Reconstituted GPMVs were observed by phase-contrast light microscopy. Subsequently, PDT was applied to GPMVs dispersed in an aqueous solution containing 50 μM MB and we verified the changes in permeability before and after exposure to light. The same processwas applied to giant unilamellar vesicles (GUVs) with lipid compositions similar to the parasite membrane. DISCUSSION AND RESULTS The electroforming technique with the protocol developed in this work made it possible to obtain GPMVs froma promastigote membrane isolate of L. amazonensis. The membrane isolation technique was effective to extract the parasite's membrane while preserving lipids and proteins. In GUVs we observe an increase in the area during PDT in different compositions and loss of contrast. The GPMVs showed a loss of contrast as well as the GUVs but did not show an increase in area. CONCLUSION This factor could be explained by the high degree of complexity of the membrane, which contains membrane proteins in addition to containing lipids.

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  • IPEN-DOC 28608

    SOUZA, TIAGO H. dos S.; ANDRADE, CAMILA; CABRAL, FERNANDA ; SARMENTO-NETO, JOSE; REBOUCAS, JULIO; SANTOS, BEATE; RIBEIRO, MARTHA ; FIGUEIREDO, REGINA; FONTES, ADRIANA. Effects of photodynamic inactivation mediated by Zn(II) porphyrin on promastigote and amastigote forms of Leishmania amazonensis. Biophysical Reviews, v. 13, n. 6, p. 1380-1381, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Photodynamic inactivation (PDI) has been attracting attention as an innovative technology to treat topical diseases, such as cutaneous leishmaniasis (CL) and infections caused by multidrug-resistant microorganisms. Zn(II) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (ZnTnHex-2-PyP 4+ ) is a lipophilic water-soluble Zn(II) porphyrin with improved photophysical properties, high chemical stability, and cationic/ amphiphilic character that can enhance its interaction with cells. OBJECTIVES Thus, this study aimed to investigate the PDI effects mediated by ZnTnHex-2-PyP 4+ on Leishmania amazonensis. MATERIALS AND METHODS Confocal fluorescence microscopy was explored to study the interaction of ZnTnHex-2-PyP 4+ with promastigotes. The PDI action was analyzed by cell membrane integrity, mitochondrial membrane potential (ΔΨm), and cell morphology. Promastigotes were incubated with ZnTnHex-2-PyP 4+ for 5 min at 0.62 and 1.25 μM and irradiated by a LED (410 nm) for 1 or 3 min (2.3 and 3.4 J/cm 2 , respectively). PDI on amastigotes and the cytotoxicity onmacrophages were also analyzed (3.4 J/cm 2 ). DISCUSSION AND RESULTS Fluorescence microscopy revealed that parasites efficiently uptake ZnTnHex-2-PyP 4+ and displayed a punctate labeling pattern along with the cytoplasm. An intenseΔΨmdepolarization was also observed, which in association with microscopy results, suggests that ZnTnHex-2-PyP 4+ may accumulate in the mitochondrion, or other well-defined structures close to it. Moreover, ZnTnHex-2-PyP 4+ at concentration as low as 0.62 μM led to the immediate inactivation of >95% of promastigotes, regardless of the light dose used. Loss of the fusiform shape and plasma membrane wrinkling were also observed. After a single treatment session in amastigotes, PDI led to a reduction of 70% in the infection index. No considerable toxicity was observed on mammalian cells. CONCLUSION Thus, PDI of Leishmania parasites showed in vitro efficiency at a submicromolar concentration of ZnTnHex-2-PyP 4+ , with short pre-incubation and irradiation times. The results encourage further studies in CL pre-clinical assays and PDI of other microorganisms.

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  • IPEN-DOC 28607

    CONTATORI, CAROLINA G. de S. ; PINTO, MAYARA S. ; RIBEIRO, MARTHA S. . Melanoma cell migration in response to red and near-infrared low-level light. Biophysical Reviews, v. 13, n. 6, p. 1380-1380, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Cell migration plays an important role in tissue formation and cancer progression. In vitro scratch assay has been used for many years to study cell migration to mimic the migration of in vivo cells, and, thus, to evaluate cancer growth. Low-level red and near-infrared light (LLL) can increase normal cell migration. However, the impact of LLL on tumor cells remains unclear. OBJECTIVES In this work, we aimed to evaluate the effects of a single LLL dose on melanoma cell migration. MATERIALS AND METHODS B16F10 (murine melanoma) cells were cultivated in RPMI medium with 10% of fetal bovine serum until they reached 80% confluency. The cell line was seeded in a 6-well plate at a density of 2x10 5 cells/well in triplicate at two different moments. A wound scratch was performed to disrupt the confluent cellmonolayerwith a 10 μL pipette tip. Immediately after the injury, the cells were submitted to the LLL at two distinct wavelengths (660 and 780 nm) provided by a LED and a laser, respectively, delivering 3 different energies (1.3, 3.6, and 6 J) at an irradiance of 4.2 mW/cm 2 . The control group was not irradiated. Cells were photographed immediately and at 3, 12, 24, and 36 h after the scratch. The wound closure was measured using ImageJ software. To evaluate the overall migration, we calculated the areas under the curve for each group. DISCUSSION AND RESULTS Cells exposed to the red laser at 6 J migrated slower than control. In contrast, LLL at 780 nm promoted faster cell migration when irradiated with 3.6 J. CONCLUSION These results suggest that low-level LEDs at 660 nm could prevent melanoma progression in higher energies. However, 780 nm should be avoided at middle energies.

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  • IPEN-DOC 28606

    MITSUTAKE, HERY; SOUZA, ALESSANDRO D. de; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D. ; CLEMENS, DANIEL; KENT, BEN; BREITKREITZ, MARCIA C.; RIBEIRO, LIGIA N. de M.; PAULA, ENEIDA de; BORDALLO, HELOISA N.. Evaluation of structural changes of benzocaine-loaded, optimized nanostructured lipid carriers using SANS and Raman imaging approaches. Biophysical Reviews, v. 13, n. 6, p. 1335-1335, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Local anesthetics are substances that reversibly block the nerve-impulse conduction, alleviating pain without loss of consciousness. Benzocaine, a poorly soluble local anesthetic, is an ester of para-aminobenzoic acid. Several strategies of formulations can be used to improve bioavailability and decrease adverse effects of benzocaine. In this study nanostructured lipid carriers (NLC) were employed. These lipid-based drug delivery carriers have a lipid core composed of a blend of solid and liquid lipids, and a shelf of non-ionic surfactant. OBJECTIVES The main aim of this work was to optimize benzocaine-loaded NLC and to investigate structural changes in these nanoparticles, under different temperatures. MATERIALS AND METHODS The ratio of excipients (cetyl palmitate, Capmul® PG-8 NF and Pluronic®F68) and benzocaine in the NLC was optimized using a 2 3 factorial design with respect to the following parameters: particle size, polydispersity index (PDI) and zeta potentials. DISCUSSION AND RESULTS The interactions between the factors were found relevant to determine particle size and PDI. Using desirability function, the best formulation conditions were found. Structural changes in optimized NLC were observed with Small-Angle Neutron Scattering (SANS) and Raman imaging, in samples at 27, 37 and 40º C. SANS pointed the formation of lamellar structures inside the NLC, which interlamellar distances increase at higher temperature. Raman imaging showed that the incorporation of P68 and benzocaine in-between the lipids increased at higher temperatures, explaining the changes in Q values (SANS). CONCLUSION This work shows how different scattering techniques can provide complementary information and be used together to characterize and understand the physical, chemical, and structural changes on the organization of pharmaceutical carriers in drug delivery system.

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  • IPEN-DOC 28605

    SANTOS, CAROLINA M. dos ; SAMPAIO, SUELEN de B.; SANTANA, FAGNER ; LEITE, RODRIGO C. ; PRATA, BEATRIZ A. ; AFFONSO, REGINA . A new approach for purification of the catalytic site of the Angiotensin Conversion Enzyme, N domain, mediated by the ELP-Inten system. Biophysical Reviews, v. 13, n. 6, p. 1305-1305, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Angiotensin-converting enzyme I, ACE, is a key part of the renin-angiotensin system whose main function is to regulate blood pressure and balance of salts in the body. ACE1 has two isoforms, somatic, sACE, and testicular, tACE. sACE possesses two domains, N- C-, with catalytic sites which exhibit 60% sequence identity. These domains differ in terms of chloride-ion activation profiles, rates of peptide hydrolysis and sensitivities to various inhibitors. N-domain has specific action in the hydrolyze of Alzheimer’s diseases beta amyloid bodies and angiotensin 1-7, which active the MAS receptor and triggering anti-thrombotic and anti-inflammatory actions. OBJECTIVES The objective this work was to obtain catalytic site Ala361 to Gli468 of the N-domain region, csACEN, isolation without chromatographic and denaturant chemical process. MATERIALS AND METHODS For that, a new methodology was used in the expression of the csACEN peptide, in which the peptide was linked to the elastin-like polypeptide, ELP, and Intein, and expressed at 37C. The characterization of catalytic site was made by SDS-PAGE and dot blotting. DISCUSSION AND RESULTS The culture temperature at 37C significantly increased the expression of the ELP/Intein/csACEN fusion protein. This culture was lysed at a low temperature allowing the fusion protein to become soluble. The precipitation of ELP at high concentrations of ammonium sulfate were obtained in 0.57 M and 0.8 M. Intein autocleavage occurs at acidic pH and it is important to pay attention to: pI 6.65 for csACEN and pI 6.87 for ELPcsACEN, which are very low. The best autocleavage efficiency was withMES and TriHCl buffers, pH 6.3 and 6.8, respectively, in which pure csACEn peptide was obtained. CONCLUSION The strategy used to obtain the Ala361 to Gli468 catalytic site in soluble and pure form was obtained with success and the protocol for obtaining similar peptides was established.

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  • IPEN-DOC 28604

    TREMARIN, BEATRIZ; YOKAICHIYA, FABIANO; KELLERMANN, GUINTHER; FRANCO, MARGARETH K.K.D. ; STORSBERG, JOACHIM. Improvement of the methodological strategies to product functionalizes antibodies using Small Angle Neutron Scattering (SANS). Biophysical Reviews, v. 13, n. 6, p. 1301-1301, 2021. DOI: 10.1007/s12551-021-00845-2

    Abstract: INTRODUCTION Antibodies are used by jawed vertebrates for defense against invading pathogens. Usage of those versatile tools in a plethora of settings in clinics and biomedical sciences hinges on functionalization strategies that retain native antibody reactivity. To this date, antibody functionalization is performed by trial and error. OBJECTIVES We aim to reduce costs by providing general principles to allow the full spectrum of antibody functionalization by correlating functionalized antibody reactivity to cognate antigen by small angle neutron scattering, SANS, measurements and mathematical modeling of antibody and antibody-antigen super-complexes, obtained by titration experiments. MATERIALS AND METHODS For this research we have used for as antibody pure goat anti rabbit immunoglobulin, and for the antigen, pure Horseradish Peroxidase Preliminary results show that the systems (antibody and antibody-antigen complexes) do not change in the range of a temperature related to storage temperature (25º C), body temperature (37º C) and 40º C. DISCUSSION AND RESULTS These results will give us the pair distribution function of these systems and the results will be viewed in light of published precedence to highlight areas where future effort is needed to refine such versatile tools and improve their production. However, between the antibody and the complexes structure, different conformations were observed. The antibody has a globular structure with a radius of gyration around 33 Å, and the complexes display an elongated cylindrical shape with radius of gyration around 63 Å. CONCLUSION This study shows how the scattering techniques (SANS) can provide useful information about the conformation of the antibody and antibody-antigen formation and help to shed light in the understanding the physical, chemical, and structural changes on the organization of these important antibody functionalization for the immunological system.

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  • IPEN-DOC 14592

    SUZUKI, L.C.; YAMADA JUNIOR, A.M. ; HAYEK, R.R.A.; RIBEIRO, M.S. . A case report of photodynamic therapy on bacterial reduction before immediate implant. Brazilian Dental Journal, v. 15, Special issue, p. 127-127, 2004.

    Abstract: Recent studies have demonstrated that a number of oral bacteria can be killed by photodynamic therapy with low concentrations of dyes. Photodynamic therapy is the combination of light with appropriate wavelength and a photosensitizer. The antimicrobial activity is mainly mediated by singlet oxygen and/or free radicals generated by the photoactivated sensitizer. A flap surgery aiming an immediate implant was made in a residual root with periodontal lesion on upper first premolar. After the extraction, a microbiological sample with sterile paper points was harvested. Then, the photosensitizer was applied in the infected alveolus and irradiated with low-intensity laser, ?= 660 nm, P= 30 mW and E= 9 J . After the photodynamic therapy, a new microbiological sample was harvested. Subsequently, it was prepared the implant bed with conical burs and then the implant was placed. Patient was medicated with antibiotic after surgery. The microbiological analysis showed a significant reduction of Prevotella sp., Fusobacterium sp. and Streptococcus beta-hemoliticus. This finding suggests that photodynamic therapy is an alternative method to disinfect alveolus before implant placement. Therefore, this study highlights the need for future work in the area of photodynamic therapy to reduce bacteria without harming host tissue.

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  • IPEN-DOC 14214

    NAKASONE, R.K.; RODRIGUES, C.R.M.D.; BUZALAF, M.A.R.; OLYMPO, K.P.K.; TANJI, E.Y.; RIBEIRO, M.S. . Effects of the low-intensity red laser radiation on the fluoride uptake in human enamel: a preliminary study. Brazilian Dental Journal, v. 15, Special issue, p. 119-120, 2004.

    Abstract: Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of lowintensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two upper central incisors of each volunteer were used and divided into 4 groups: group GC (control), which was untreated; group GF (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group GLF (laser + fluoride), which was irradiated with a low-intensity diode laser (l= 660 nm and dose= 6 J/cm²) with APF application after irradiation and group GFL (fluoride + laser), which received APF before irradiation using the same parameters as GLF. The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results showed a significant increase of the fluoride uptake in enamel for groups GF, GLF and GFL when compared to control group. Although a percentage increase of 57% was observed for GLF with respect to GF, there were no statistical differences among the treated groups. These findings motivate further studies in order to introduce low-power laser associated to APF as a protective method of dental caries.

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  • IPEN-DOC 14036

    MULLER, K.P. ; YAMADA JUNIOR, A.M. ; SUGAYAMA, S.T.; RIBEIRO, M.S. . Local Treatment using high and low-power laser on herpes simplex. Brazilian Dental Journal, v. 15, Special issue, p. 119-119, 2004.

    Abstract: Herpes simplex (HSV) is commonly encountered in the dentistry practice disappearing after 10 to 14 days. Recently alternative treatments have been introduced, among those laser therapy. The aim of this study is to evaluate the efficacy of laser therapy in patients with perioral herpes simplex infection. A 32 years old female was treated with high-intensity laser therapy (HILT) in vesicle phase using a Nd:YAG laser, l= 1064 nm, P= 1,5 W, f= 15 Hz on days 1 and 2 to drainage the vesicles. Low-intensity laser therapy (LILT) was applied on the affected area in the 3 consecutive days with a GaAlAs laser, l= 830 nm, D= 5 J/cm2. On the other hand, a 7 years male patient, which presented the vesiculo-ulcerative stage, only LILT (l= 660 nm, D= 4 J/cm2) was carried out. For both cases, it was observed that the course of the infection was quicker than the normal. Seven days after treatment beginning the lesions were healed. These findings suggest that LILT associated or not to HILT is a efficient and promising treatment for HSV. Further larger studies aiming at confirming these data and investigating the LILT mechanisms of action should be performed.

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  • IPEN-DOC 13067

    LOLLATO, R.F.; GROTH, E.B.; RIBEIRO, M.S. . Low-intensity laser therapy and functional orthopedics in the treatment of pain from temporomandibular disfunction. Brazilian Dental Journal, v. 15, Special issue, p. 114-114, 2004.

    Abstract: Temporomandibular Disfunction (TMD) is a term used to describe disorders, which involve temporomandibular joint (TMJ), masticatory muscles, and associated structures, isolated or not, whose most frequent symptom is pain. The aim of this study was to evaluate pain and buccal mobility in subjects with Cl II malocclusion and TMD symptoms, treated with low-intensity laser therapy (LILT) and functional orthopedics (FO), associated or not. Eighteen subjects were selected and divided into three groups. Group 1 was treated with LILT, l = 780nm, 70 mW, 15 J/cm2 per point during two weeks. The application was in three points around the TMJ, and trigger points of masticatory muscles. Group 2 received Planas functional appliances and it was evaluated once a week during two weeks. Group 3 received both treatments at the same time, and the first laser application coincided with the appliance installation. Subjects answered a questionnaire with a score for pain evaluation after palpation. There was pain relief for the 3 groups and no statistical differences were observed among them, however, group 3 showed a remission of pain faster than other groups. This finding indicates the association of the LILT with FO for pain relief in TMD.

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  • IPEN-DOC 13052

    KOHARA, E.K. ; KATO, I.T.; WETTER, N.U. . Effects of 960nm diode laser irradiation and fluoride on calcium solubility of dental enamel in vitro. Brazilian Dental Journal, v. 15, Special issue, p. 112-112, 2004.

    Abstract: The aim of this study is to determine the effects of diode laser (?=960 nm) irradiation on calcium solubility of dental enamel. Sixty enamel specimens were prepared from human teeth and divided into four groups (control, fluoride, laser and fluoride plus laser). Prior to the irradiation a vegetable coal diluted in physiological solution was applied to the enamel surface and the specimens were irradiated using 6,5 W of peak power, 5 ms of pulse duration, 10 Hz of repetition rate, fluency of 3,7 J/cm2 and time exposure of 10 seconds. The acidulated phosphate fluoride was applied for 4 minutes. Next, the specimens were immersed in lactic acid for 24 hours at 37 °C. The calcium content in demineralization solution was evaluated with Inductively Coupled Plasma Atomic Emission Spectrometry. The results indicate an increase in calcium solubility (12%) after laser irradiation, however, not statistically significant. When associated with fluoride, the decrease in calcium solubility did not differ from the results obtained with fluoride only. It can be concluded that in this experiment diode laser irradiation did not increase acid resistance of dental enamel.

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  • IPEN-DOC 13050

    KOHARA, E.K. ; WETTER, N.U. ; RATTICHIERI, F.; KATO, I.T.. Microhardness of the dental enamel surface after irradiation with 960nm diode laser. Brazilian Dental Journal, v. 15, Special issue, p. 111-112, 2004.

    Abstract: Several authors analyzed laser irradiation of dental enamel in an attempt to increase acid resistance and achieve caries prevention. In some cases, the procedure has also been associated to the application of a layer of fluoride. Micro-hardness measurements are reliable tests used to determine the degree of resistance to demineralization. In this work micro-hardness values of superficial dental enamel have been measured before and after irradiation with a 960 nm diode laser, using tested laser parameters that are safe and cause no injuries to the adjacent tissue. Laser parameters were below the dental enamel ablation threshold. 60 enamel samples were used and divided into control group (GC), fluoride application (GF), laser irradiation (GL), fluoride application with subsequent laser irradiation (GFL) and laser with subsequent fluoride application (GLF). A solution containing coal was used on the enamel surface in order to absorb the laser radiation. A statistically significant loss of the micro-hardness value was obtained for all groups except for GL but also this group did not produce significant micro-hardness increase. Conclusion: at the current peak power and beam quality of standard diode laser bars, safe laser parameters do not produce higher micro-hardness values.

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  • IPEN-DOC 13014

    CAMARGO, A.; BALDOCHI, S. ; CAMARGO, S.; EDUARDO, C.P.. "In vitro" evaluation of morphologic changes on the root dentine irradiated by CO2 laser associated or not to calcium hydroxide. Brazilian Dental Journal, v. 15, Special issue, p. 102-103, 2004.

    Abstract: This in vitro study has evaluated the structural changes on the root dentine irradiated by a CO2 laser associated or not to calcium hydroxide - an alternative method for dentine hypersensitivity treatment. Fourteen human teeth 3rd molars were utilized, divided into 7 groups. Group I (control group),Groups II, III and IV received an application of Ca (OH)2 paste followed by CO2 laser irradiation for 5 seconds, intervals of 10 seconds, continuous emission, power of 0.5W, constant distance of 30mm (Group II), 1.0W (Group III), 1.5W (Group IV); Groups V, VI, VII received laser irradiations following the same parameters applied to groups II, III, and IV. Morphologic changes suggesting to fusion and re-solidification were observed, and the presence of material obstructing the whole analyzed surface on groups II, III, and IV. For groups V, VI, and VII, fusion, re-solidification, and cracks, were observed, results statistically significant (P<0,01). No statistically significant differences were observed in groups that used the same treatment. Powers above 1.0W (DP=125,38W/cm2) showed carbonization and dark surface, results unfavorable due to the undesirable morphologic alterations and aesthetic compromising.

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  • IPEN-DOC 13005

    ARCHILLA, J.R.F.; TANNOUS, J.T.; PELINO, J.E.P.; FREITAS, P.M.; SILVA, D.F.T.; RIBEIRO, M.S. . Spectroscopic analysis and interaction of different bleaching agents with 660n laser and 470 nm LED. Brazilian Dental Journal, v. 15, Special issue, p. 100-100, 2004.

    Abstract: The aim of this in vitro study was to verify the effect of different dental bleaching methods regarding the achromatic enamel color change. Forty-five bovine teeth were immersed in a darkening solution and then divided into nine experimental groups with five samples in each group. The color measurement was initially taken using a digital colorimeter. The teeth were submitted to the bleaching with three bleaching gels, without any activation source (control) and with two wavelengths (660 nm diode laser and 470 nm LED). The previous analysis of the absorption spectra enabled the choice of an adequate wavelength in order to enhance its photochemical action. The second color measurement was taken after all the treatments. The data were submitted to ANOVA and Tukey parametric statistical tests (p=0,05). It was observed that: 1) there was a statistical significant difference between the activation sources; 2) there was statistical significant difference regarding the interaction among the activation sources and the bleaching gels when compared with each other. The activation methods of the bleaching agents, even promoting color changes in distinct levels, still require further studies capable of detecting a higher absorption spectrum of a product and which presents significant clinical results.

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  • IPEN-DOC 13002

    TODESCAN, C.D.R.; VIEIRA JUNIOR, N.D. ; SAMAD, R.E. ; FREITAS, A.Z. ; EDUARDO, C.P.. Ultrashort pulses over bovine dental enamel. Brazilian Dental Journal, v. 15, Special issue, p. 91-91, 2004.

    Abstract: The interaction of lasers with the hard structures of the teeth, has found the excess of heat as a problem for its utilization. This study analyzes, in vitro, the interaction of the ultrashort pulse laser of Ti:safire (830 nm) with the bovine dental enamel. The system consisted in one main oscillator integrated with an amplifier (CPA). The pulses extracted before the temporal compression inside the amplifier had 30ps, 1000Hz and ~1mJ. The pulses extracted after the compression had 60fs, 1000Hz and ~0,7mJ. The M2 was 1,3, the focal lens 2,5 cm, the focal distance 29,7 and a computadorized translation stage x,y,z moved the sample. We evaluated the amount of tissue removed per pulse,the resulting cavities and the surrounding tissues not irradiated, under OM and SEM. The fluency was the major factor for differentiating the two regimens studied, therefore, the intensity was not so important as we expected in this process. We found: one ablation region in "cat tonge", one ablation length, one fluency ~0,7J/cm2 for 30ps and ~0,5J/cm2 for 60fs (50% ofhigh speed burr), smooth edge for 30ps and high precision of the shrp edge cut of submicrometric order for 60fs.

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  • IPEN-DOC 12992

    GODOY, B.M.; ARANA-CHAVEZ, V.E.; BORTOLI GROTH, E.B.; RIBEIRO, M.S. . Effects of low-intensity red laser radiation on the dentine-pulp interface after class I cavity preparation disfunction. Brazilian Dental Journal, v. 15, Special issue, p. 86-87, 2004.

    Abstract: The aim of this study was to investigate the effects of low-intensity red laser radiation on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Eight premolars indicated for extraction for orthodontic reasons from 2 patients were used. Class I cavities were prepared and the teeth were divided into two groups. The first group received a treatment with a GaAlAs laser, l= 660 nm, P= 30 mW and D= 2J/cm2. The laser tip was applied directly and perpendicularly into the cavity in only one sense. The teeth from the second group had their class I cavities prepared but they did not receive the laser therapy. All cavities were filled with composite resin. Twenty-eight days after the preparation, the teeth were extracted and processed for transmission electron microscopy analysis. Two sound teeth (healthy group) without any preparation were also examined. The first group presented odontoblastic processes in intimate contact with the extracellular matrix, while the collagen fibers appeared more aggregated and organized than those of the second group. These results were also observed in the healthy teeth. The results suggest that laser irradiation accelerates the recovery of the structures at the dentine-pulp interface involved during cavity preparation layer.

    Palavras-Chave: teeth; dentin; oral cavity; lasers; radiation effects

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  • IPEN-DOC 12991

    NUNEZ, S.C. ; GOMES, L.; GARCEZ, A.S.; LAGE-MARQUES, J.L.. Comparative study between photodynamic therapy and chemical solution on bacterial reduction in root canals. Brazilian Dental Journal, v. 15, Special issue, p. 85-85, 2004.

    Abstract: One of the major medical problems facing mankind in the next century will be the resistance of many pathogenic microbes to existing antibiotics. Oral bacteria can easily reach other body sites and also spread to other individuals. Therefore, antibiotic-resistant oral bacteria have the opportunity for rapid dissemination through the community and to transfer their resistance genes to other bacterial species. Photodynamic therapy involves the use of light-activated drugs which may offer an alternative approach to the use of traditional antimicrobial agents. The purpose of this study was to evaluate bacterial reduction in infected root canal. Thirty teeth with their root canals prepared were contaminated with Enterococcus faecalis. Control group was untreated. Chemical group was treated with sodium hypochlorite for 30 minutes and in the laser group, a photosensitizer paste was placed and maintained in the root canals for 5 minutes and irradiated with a diode laser, output power 10 mW and l= 685nm for 3 minutes. The bacterial reduction was significantly higher for laser group when compared to chemical and control groups. These results indicate photodynamic therapy as an effective method to kill E. faecalis.

    Palavras-Chave: photodynamic therapy; oral cavity; teeth; antimicrobial agents; microbial drug resistance

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  • IPEN-DOC 12376

    NUNEZ, S.C. ; GOMES, L.; GARCEZ, A.S.; MULLER, K.P. ; JORGE, A.O.C.; RIBEIRO, M.S. . Photodynamic action of toluidine blue in streptococcus mutans by fluorescence spectroscopy. Brazilian Dental Journal, v. 15, Special issue, p. 84-85, 2004.

    Abstract: The antimicrobial activity of toluidine blue associated with red light has been demonstrated for a wide range of microorganisms including those commonly found in infected root canals, carious lesions and periodontal pockets. Recent reports have drawn attention to the problems of antimicrobial resistance and resistance of oral bacteria to antibiotics and local antiseptics is of increasing concern, thus photodynamic therapy could be an alternative antimicrobial approach to treat localized infections in oral cavity. In this study the fluorescence spectra of TB were obtained before and after laser exposure in the presence or absence of Streptococcus mutans. The dye concentration was 0.01%, the irradiation was performed with a diode laser, l= 660 nm, P= 40mW, exposure time of 3 minutes in a volume of 0.5 ml, with a pre-irradiation time (PIT) of one or five minutes. The results showed shifts in fluorescence spectra observed for different preirradiation times in the presence of S. mutans. In the absence of bacteria, a shift in the spectra was observed in the dye before and after irradiation. These findings may indicate a photobleaching of the dye denoting structural alterations after irradiation and confirm the importance of the PIT for the success of this therapy.

    Palavras-Chave: dentistry; caries; bacteria; antimicrobial agents; toluidine blue

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  • IPEN-DOC 11770

    YAMADA JUNIOR, A.M. ; HAYEK, R.R.A.; GIOSO, M.A.; FERREIRA, J.; BATISTA SOBRINHO, C.A.; RIBEIRO, M.S. . Bacterial reduction by photodynamic therapy in peri-implantitis: an in vivo study. Brazilian Dental Journal, v. 15, Special issue, p. 84-84, 2004.

    Abstract: Progressive peri-implantar bone losses, which are accompanied by inflammatory process in the soft tissues is referred to as peri-implantitis. The aim of this study was to compare the effects of lethal photosensitization with the conventional technique on bacterial reduction in ligature induced peri-implantitis in dogs. Seventeen third premolars of eight Labrador dogs were extracted and, immediately after, the implants were submerged. After osseointegration, peri-implantitis was induced. After 4 months, ligature were removed and the same period was waited for natural induction of bacterial plaque. The dogs were randomly divided into two groups. In the conventional group, they were treated with the conventional techniques of mucoperiosteal flaps for scaling the implant surface and irrigation with chlorexidine. In the laser group, only mucoperiosteal scaling was carried out before photodynamic therapy. On the peri-implantar pocket an azulene paste was introduced and a GaAlAs low-power laser (l= 660 nm, P= 30 mW, E= 5,4 J and Dt= 3 min.) was applied. Microbiological samples were obtained before and immediately after treatment. The results of this study showed that Prevotella sp., Fusobacterium e S. Beta-haemolyticus were significantly reduced for the conventional and laser groups (100%,99.8%; 100%,100%; 85.7%,97.6%, respectively).

    Palavras-Chave: dentistry; teeth; implants; bone tissues; bacteria; photodynamic therapy; lasers; photosensitivity

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  • IPEN-DOC 11228

    KOHARA, E.K. ; CRUZ, D.R.; WETTER, N.U. ; RIBEIRO, M.S. . Effects of low-intensity laser therapy on the Orthodontic movement velocity of human teeth: a clinical study. Brazilian Dental Journal, v. 15, Special issue, p. 84-84, 2004.

    Abstract: Low-intensity laser therapy (LILT) has been studied in many fields of Dentistry, but, to our knowledge, it is the first time that its effects on orthodontic movement velocity in humans are investigated. In our study, eleven patients were recruited for a two-month study. One half of the upper arcade was considered control group and received mechanical activation of the canine teeth every thirty days. The opposite half received the same mechanical activation and was also irradiated with a diode laser (?=780nm) on ten points around the root, during 10s with 20 mW, 5 J/cm2, on four days of each month. Data of the biometrical progress of both groups were statistically compared. All patients showed significant higher retraction velocity of the canines on the laser treated side when compared to the control. Conclusion: Our findings suggest that LILT does accelerate human teeth movement and could therefore considerably shorten the whole treatment duration.

    Palavras-Chave: teeth; orthodontic treatments; semiconductor lasers; light emitting diodes; therapy; bone tissues

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  • IPEN-DOC 11177

    BARROSO, M.C.S.; WETTER, N.U. ; PELINO, J.E.P.. Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study. Brazilian Dental Journal, v. 15, Special issue, p. 77-77, 2004.

    Abstract: Objective: This in vitro study evaluated the whitening efficacy of LED and diode laser irradiation during the dental bleaching procedure, using the two agents Opalescence X-tra and HP Whiteness. Background: Bleaching techniques achieved significant advances with the use of coherent or incoherent radiation sources to activate the bleaching chemicals. Methods: Atotal of 60 bovine incisors were randomly divided into six groups, three for each bleaching agent, receiving 1) only agent, 2) agent and LED irradiation at wavelength of 470 nm, 3) agent and 1.6 watt diode Laser at 808 nm. The results of the irradiations were characterized with the CIELAB system by measuring the L*a*b* values for the teeth before and after bleaching. Results: The average increase of the lightness value (CIELAB L*) of the different groups was 3-7 and the average chroma value decreased by 5-9. Conclusions: This is to our knowledge the first time that the light sources Laser and LED are compared with respect to their whitening capability when applied to different agents. Best overall results are obtained with the Whiteness HP and Laser association.

    Palavras-Chave: teeth; bleaching; enamels; semiconductor lasers; light emitting diodes

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  • IPEN-DOC 10875

    HAYEK, R.R.A.; YAMADA JUNIOR, A.M. ; GARCEZ, A.S.; NUNEZ, S.C. ; SUZUKI, L.C.; RIBEIRO, M.S. . Comparation between photodynamic therapy and a bactericidal solution in the treatment of dental alveolitis microbiological evaluation. Brazilian Dental Journal, v. 15, Special issue, p. 110-110, 2004.

    Abstract: Photodynamic therapy is a new therapeutic modality to treat microbial infections. The aim of this pilot study was to compare this new therapeutic approach with clorhexidine in mini pigs induced alveolitis. Alveolitis is an inflammatory disease that involves the superficial bone layer in the dental alveolus. Eight dental elements were extracted from mini pigs and immediately after the alveolus were contaminated with Streptoccocus aureus. After seven days the area presented edema and hyperemia. In the clorhexidine group the alveolus were debrided and irrigated with a 0.12% solution of clorhexidine. In Laser group the alveolus were debrided and photodynamic therapy was performed consisting in the application of a azulene paste inside the alveolus with a preirradiation time of 5 minutes followed by irradiation with a low power diode laser, ?= 685 nm, P= 50 mW, E= 9 J, for 3 minutes. Microbiological samples were harvested before and after treatment for both groups with sterile paper points. The results showed bacterial reduction in both groups, although photodynamic therapy was significantly more effective to reduce the population of S. aureus. This finding indicates that photodynamic therapy can be an alternative method to the treatment of alveolitis.

    Palavras-Chave: dentistry; photodynamic therapy; germicides; inflammation

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  • IPEN-DOC 10464

    ZEZELL, D.M. ; BEVILACQUA, F.M.; MAGNANI, R.; ANA, P.A. ; EDUARDO, C.P.. Fluoride incorporation and acid resistance of dental enamel irradiated with Er:YAG: atomic absorption spectrometry and spectrophotometry. Brazilian Dental Journal, v. 15, Special issue, p. 131-131, 2004.

    Abstract: Er:YAG effects on dental enamel surface regarding the resistance to demineralization and the fluoride incorporation were evaluated. 80 samples were divided into 8 groups: G1) control - APF application; G2) conditioning with 37% phosphoric acid and APF application; G3) irradiation with 250 mJ/pulse, 7 Hz, 31,84 J/cm2 (contact) and APF application; G4) irradiation with 200 mJ/pulse, 7 Hz, 25,47 J/cm2 (contact) and APF application; G5) irradiation with 150 mJ/pulse, 7 Hz, 19,10 J/cm2 (contact) and APF application; G6) irradiation with 250 mJ/pulse, 7 Hz, 2,08 J/cm2 (non-contact) and APF application; G7) irradiation with 200 mJ/pulse, 7 Hz, 1,8 J/cm2 (non-contact) and APF application; G8) irradiation with 100 mJ/pulse, 7 Hz, 0,9 J/cm2 (noncontact) and APF application. All samples were immersed in 2,0 M acetic-acetate acid solution, pH 4,5 for 8 hours. The fluoride, calcium and phosphorous ions were analyzed, by atomic absorption spectrometry and spectrophotometry. Groups laser irradiated before topic APF application presented better results than the control. There was higher fluoride incorporation on G7 and G8. Calcium and phosphorous analysis reveled a decrease on the enamel demineralization on G2 and G3 groups. The Er:YAG laser on irradiation conditions of this work is a promissory alternative for the Preventive Dentistry.

    Palavras-Chave: dentistry; enamels; lasers; laser radiation; fluorides

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  • IPEN-DOC 10306

    ZEZELL, D.M. ; MIYAKAWA, W.; RIVA, R.; WATANUKI, J.T.. Monte-Carlo Modelling of light propagation in hard dental tissues. Brazilian Dental Journal, v. 15, Special issue, p. 131-131, 2004.

    Abstract: In the Monte-Carlo model, we simulated the propagation of visible light and the temperature distribution in human tooth, which reflects the energy deposited in the tooth by the laser. As a turbid medium, differences in absorption and scattering coefficients of the enamel and dentine must be taken into account. These data are not completely established in the literature in the visible range. The results are compared with experimental data of Cu-HyBrID laser light propagation in human molar teeth, in order to evaluate the scattering coefficient. The Cu-HyBrID laser emits green (510 nm) and yellow (578 nm) radiation with high output peak power (20 kW) at high repetition rates (13.7 kHz) and there is almost no report of its use in Dentistry. This work aims to correlate the Cu-HyBrID energy deposition with the tooth thermal response. The tooth is predominantly a scattering medium (absorption much lower than scattering) and small variations in the absorption coefficient do not reveal significant alterations in the light distribution curve. According to the simulation, most of the laser energy is accumulated on enamel-dentine junction and the tooth thermal response is strongly affected by the value of the absorption coefficient, which is not yet precisely known.

    Palavras-Chave: dentin; teeth; laser radiation; monte carlo method; simulation; enamels

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  • IPEN-DOC 09172

    HAYPEK, P.; THEODORO, L.H.; BACHMANN, L. ; EDUARDO, C.P.; SAMPAIO, J.E.C.; ZEZELL, D.M. . Effects of the diode laser irradiation on root surfaces: thermal analysis. Brazilian Dental Journal, v. 15, Special issue, p. 110-110, 2004.

    Abstract: The purpose of this study was to evaluate the temperature rising inside the pulpar cavity during the diode laser irradiation on the root surface. Twelve single root teeth were used and their mesial and distal surfaces were irradiated (808 nm, 400 m, 30 s), in a continuous mode (CW) and in an switched mode (SW) (10 Hz). The temperature rise was evaluated deppending with the power used (0.4 W to 2.2 W). The temperature was monitorated with a termopar (T) fixed inside de pulpar cavity during the irradiation. In a second step two parameters was used in a SW (10 Hz). The safety temperature was keep using the power: Group A - 0.9 W (mesial ) and Group B - 1.08 W (distal). The results showed the termal pulpar events (T) during the irradiation, based in an specific relation with the power (P), like T= -0.4+3.7P in a CW and T= -0.2+2P in a SW. The temperature rising during the irradiation was 3.4±0.4ºC on Group A and 4.0±1.0ºC on Group B. The irradiation mode and the power are much important to temperature rise inside the pulpar cavity and the 0.9 W and 1.08 W radiation on the root surfaces were safety.

    Palavras-Chave: semiconductor diodes; laser radiation; dentin; temperature dependence; teeth

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  • IPEN-DOC 08515

    FERNANDES, A.S.F.; NAVARRO, R.S.; GONTIJO, I.; HAYPEK, P.; ZEZELL, D.M. ; HADDAD, A.E.. Intrapulpar temperature variation in primary teeth during cavity preparation using: Er:YAG laser and conventional high-speed drill. Brazilian Dental Journal, v. 15, Special issue, p. 106-107, 2004.

    Abstract: Increases of temperatures superior than 5-5.5°C can compromise the pulp vitality. The purpose of this in vitro study was to compare the variation of the pulp temperature in primary teeth during the cavity preparation. Twelve primary lower incisors (Human Tooth Bank-FOUSP) were divided in 4 groups (n=3): cavity preparations were performed at buccal surface, refrigerated by air-water spray, during 20sec, using #1090 diamond burr in highspeed drill in carious-free incisors (G I) and carious incisors (G II); or Er:YAG laser (2.94μm)(KaVo 3)(LELO-FOUSP), with 6Hz repetition rate/ 600mJ energy as orientated by manufacturer, in carious-free incisors (G III) and carious incisors (G IV). The variation of temperature was measured using digital oscilloscope and thermocouple type K placed inside the pulpar chamber, simultaneously the teeth was kept under water thermal bath during the procedures. The temperatures rises were less than 4ºC in all cavities preparations in different groups, the variation of temperature in laser and conventional high-speed drill groups showed similar values. The groups of carious teeth showed higher increase of temperature than carious-free teeth. The Er:YAG laser demonstrated be a safe alternative for cavities preparations in primary teeth, since that using effective and safety parameters by qualified and trained professionals.

    Palavras-Chave: teeth; temperature dependence; caries

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  • IPEN-DOC 08431

    EDUARDO, P.L.P.; BACHMANN, L. ; SALVADOR, V.L.; ZEZELL, D.M. . Chemical Modification of bovine dental enamel irradiated with holmiun laser. Brazilian Dental Journal, v. 15, Special issue, p. 106-106, 2004.

    Abstract: This study investigated Ho:YLF (2,065 mm) effects on dental enamel with regards to the thermal variations in the pulp chamber during irradiation and resistance to demineralization. Twenty samples of bovine enamel were divided: 1) control- acidulated phosphate fluoride (APF) topic application followed by demineralization treatment with lactic acid; 2) Ho:YLF irradiation (100J/cm2) followed by APF and demineralization; 3) Ho:YLF irradiation (350J/cm2) followed by APF and demineralization; 4) Ho:YLF irradiation (450J/cm2) followed by APF and demineralization. All samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments. X-Ray fluorescence spectrochemical analysis showed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF (ANOVA, Tukey p<0,01). To evaluate the feasibility of this study for clinical purposes, surfaces morphology were analyzed. Modifications were characterized by melted and re-solidified regions of the enamel, which can changes its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm2 and 450 J/cm2 were also monitored in the pulp chamber in real time. Temperature increases were limited to 4,2° C.

    Palavras-Chave: teeth; dentin; animals; cattle; enamels; laser radiation; holmium; chemical composition

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  • IPEN-DOC 08368

    ANA, P.A. ; VELOSO JUNIOR, W.F.; CLAUDIO, T.; ZEZELL, D.M. . 3D-Finite element and thermographic analysis of human teeth irradiated with ErCrYSGG. Brazilian Dental Journal, v. 15, Special issue, p. 99-99, 2004.

    Abstract: The purpose of this study was to analyse surface and pulpal temperature changes in extracted human teeth subjected to Er,Cr:YSGG laser irradiation by using Finite Element Method (FEM) and comparing with thermal analysis made by thermocouple and thermocamera. Twelve extracted human molar teeth were selected and divided into three groups, according to the following Er,Cr:YSGG laser irradiation conditions: 2.8 J/cm2, 5.6 J/cm2 and 8.5 J/cm2. During laser irradiation, surface temperature was measured using a thermocamera (FLIR Systems - USA) and the pulpal temperature was monitored by means of a thermocouple type T placed in the pulpal chamber. For FEM analysis, it were constructed numerical models that reproduced a typical sound molar teeth and the analysis simulated the absorption of the laser energy and the heat transfer through the tooth in three dimensions, considering the same laser energy and conditions performed in thermocouple and thermocamera measurements. The results showed that theoretical FEM calculation showed good agreement with the thermocamera and thermocouple obtained data, simulating heat transfer and predicting the temperature increase. It was possible to conclude that 3D Finite Element Method gives good results that makes possible to understand the thermal behavior of dental material.

    Palavras-Chave: teeth; finite element method; thermography; laser radiation

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  • IPEN-DOC 08253

    ANA, P.A. ; ROCHA, R.M.M.; BLAY, A.; AUN, C.E.; LAGE-MARQUES, J.L.; ZEZELL, D.M. . Effects of Er, Cr:YSGG Laser irradiation on endodontics system permeability. Brazilian Dental Journal, v. 15, Special issue, p. 99-99, 2004.

    Abstract: The aim of this study was to evaluate the effects of Er,Cr:YSGG laser irradiation on root dentin permeability. Twenty extracted single-rooted teeth were instrumented with K-files and divided in four groups, according to laser fluences: GI (non-irradiated), GII (12.5 mJ/pulse; 2.8 J/cm2), GIII (25 mJ/pulse; 8.5 J/cm2) and GIV (75 mJ/pulse; 16.98 J/cm2). Lased groups had an association of irrigating solution EDTA-T and Er,Cr:YSGG laser irradiation, which was performed at 20 Hz repetition rate without airwater spray, with four helicoidal movements during approximately 5 seconds. NDP associated with rhodamine B dye was used to evaluate dentin permeability. After the experimental period, the samples were transversely cut into six 2.0 mm thick slices for subsequent reading using the ImageLab software. The results showed that dentin permeability of root canals was decreased when exposed to Er,Cr:YSGG laser irradiation compared with non-irradiated samples, and this alteration was higher when higher fluences were applied. The cervical and middle thirds had permeability values statistically similar (p > 0.05) and significantly greater than the apical third. It can be concluded that the use of Er,Cr:YSGG laser irradiation at the utilized parameters decreases dentin permeability, favoring the root canal sealing.

    Palavras-Chave: dentin; laser radiation; permeability

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  • IPEN-DOC 08225

    EDUARDO, F.P.; NICOLLI FILHO, W.; MIGLIORATI, C.A.; ZEZELL, D.M. ; EDUARDO, C.P.; SCHUBERT, M.M.. Effects of low intensity laser radiation in the prevention of oral mucositis in patients undergoing bone marrow transplant. Brazilian Dental Journal, v. 15, Special issue, p. 97-97, 2004.

    Abstract: Oral mucositis is one of the complications arising from pre bone marrow transplant conditioning, which can substantially change the patient's quality of life. The purpose of this randomized double blind study was to compare the effects of low intensity laser radiation in the prevention of oral mucositis in patients undergoing bone marrow transplants. Seventy patients at the Seattle Cancer Care Alliance in the U.S.A. were approved by the local ethics committee and gave their informed consent to take part in the study. The 70 patients were divided into three groups (group 1 - laser 650nm; group 2 - laser 780nm and group 3 placebo). The therapy or placebo treatment began on the first day of the conditioning and continued through to two days following the bone marrow transplant. Mucositis was measured according to the oral mucositis rate and the pain assessment rate (VAS). We were thus able to conclude that the diode 650nm laser indeed decreased the severity of oral mucositis as well as the degree the pain when used as a preventative therapy in patients undergoing bone marrow transplants. In this study, low intensity laser therapy was regarded as safe and did not present any side effects.

    Palavras-Chave: low dose irradiation; oral cavity; mucous membranes; lasers; semiconductor diodes; transplants; bone marrow

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  • IPEN-DOC 06392

    PAIVA, P.F.; PAIVA, G.; NASR, M.K.; NUNES, L.J.; MOREIRA, L.A.; ZEZELL, D.M. . Cavity preparation with ER:YAG laser: pain evaluation. Brazilian Dental Journal, v. 15, Special issue, p. 94-94, 2004.

    Abstract: They were selected for this work clinic patient of the which were selected 15 teeth with decay lesion, being ten teeth with lesion type class I, of these five for the group-control with high conventional rotation, and five for the group laser class I, and five teeth with lesion type class Vfor the group laser. In the preparations with laser of Er:YAG (Kavo Key Laser 2), any patient do not was anesthetized, even in the deepest cavities, and the maximum degree of pain (that varied from 0 to 10) it was of 4. In the group-control, with mounted tip in high conventional rotation, two patients were anesthetized, and the maximum degree of pain was of 7. The use of the laser in the dental clinic (restorative dentistry), using the technology laser in the dental preparations, it showed to be a good alternative to the use of the mounted tip in high conventional rotation. 94

    Palavras-Chave: dentin; teeth; oral cavity; lasers; biological recovery; pain

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  • IPEN-DOC 06281

    GUIMARAES, J.G.A.; MIYAKAWA, W.; STOLF, S.F.; SILVA, E.M.; ZEZELL, D.M. ; EDUARDO, C.P.. In vitro thermographic measurement in pulpal chamber during diode laser bleaching. Brazilian Dental Journal, v. 15, Special issue, p. 94-94, 2004.

    Abstract: Thermographic was employed to determine the temperature rise in lower incisors pulpal chambers during diode laser bleaching. Two methods were used: a thermocouple for 72 teeth and a infrared (IR) thermographic camera for 36. Two bleaching agents, both 35% hydrogen peroxide- Whiteness HP (HP) and Hi Lite (HL) - were applied to the specimens buccal surfaces and irradiated with a diode laser (808 5nm), CW for 30s. Intensities tested were 21.W/cm2, 29.8W/cm2, 35.8W/cm2, 38.2W/cm2, 52.9W/cm2 e 63.7W/cm2. Means of the greatest temperature rises with the HL were statiscally lower than the HP (p<0.01). When HP was irradiated with 50.9W/cm² and 61.1W/cm², the temperature registered was over 5.5ºC, considered as the limit to avoid pulp damage. The IR thermacam analysis showed that, when the HP was used, the temperature rise in pulp chamber was similar to the target area on the buccal surface. Evaluation of tooth color was done using a VITAshade guide at baseline and at the end of the bleaching treatment. Both products proved to be efficient, however HP produced statiscally higher shade changes than HL (p<0.01). It can be concluded that the diode laser bleaching associated with the HP was safe when intensities below 50mW/cm2 were employed. Higher parameters can cause damage to pulp vitality of the lower incisors, fact that did not occurred with the HL gel. Both gels were efficacious to the bleaching technique proposed, but the HP showed better results.

    Palavras-Chave: dentin; teeth; bleaching; thermography; hydrogen peroxide; semiconductor diodes; lasers

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  • IPEN-DOC 05701

    GONTIJO, I.T.; CIAMPONI, A.L.; ZEZELL, D.M. ; NAVARRO, R.; RODRIGUES, W.; CIAMPONI, A.L.. In vitro and in vivo evaluation of deciduos teeth withening technique: the diode laser and light cure. Brazilian Dental Journal, v. 15, Special issue, p. 93-93, 2004.

    Abstract: A great number of children suffer from traumatic injuries on the deciduous dentition. The darkening resulting from these injuries create an aesthetic probem in these children in the middle of their psychosocial development. The whitening technique might be a satisfactory aesthetic resolution, as well as non-invasive. The objectives of the present study were to evaluate "in vitro" and "in vivo" the teeth color variation and superficial temperature, obtained by the thermocatalytic technique used in devitalized human deciduous teeth, as well as evaluate "in vivo" the teeth color variation obtained by the whitening. The whitening agent was the hydrogen peroxide 35%,having as a variant the source of catalyzing energy- diode laser and the light curer. 21 deciduous teeth were utilized. The light curer group-11 teeth and the laser group, 10.The color evaluation was carried out by the spectrophotometer and VITA 3D scale. After statistic analysis, it can be concluded that the whitening was verified by both methods.The temperature variation was significantly higher in the light cure group than in the laser group.

    Palavras-Chave: dentin; teeth; hydrogen peroxide; semiconductor diodes; bleaching

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  • IPEN-DOC 05446

    ANDRADE, A.K.P.; FEIST, I.S.; CAI, S.; PANNUTI, C.; ZEZELL, D.M. ; DE MICHELI, G.. Bacterial reduction in class II furcation after root debridment with or without Nd:YAG laser irradiation. Brazilian Dental Journal, v. 15, Special issue, p. 90-91, 2004.

    Abstract: The use of Nd:Yag laser for bacterial reduction as an adjuvant to nonsurgical periodontal treatment has been approached in several studies. Furcation complex anatomy is responsible for comprised treatment results in this areas due to the lack of proper access for instrumentation showing the persistence of a pathogenic microbial flora. The purpose of this clinical trial, randomized, double-blinded was to evaluated the bacterial reduction achieved with the Nd:YAG associated to conventional treatment on furcation sites of patients with chronic periodontitis. In a split mouth design study, 34 class II furcations that were selected from 17 patients with chronic periodontitis. They received previous full mouth periodontal treatment, except for the experimental sites. The 17 furcations of the Control group underwent twice manual and ultrasonic root debridment in weekly intervals. The Test group received the same treatment as the Control group followed by the Nd:YAG laser application (100mJ/pulse; 1.5W; 15Hz; 60sec). The microbiological parameters total numbers of anaerobic Colony Forming Units(CFU); Black pigmented CFU and the level of Actinobacillus actinomycetemcomitans(Aa), Porphyromonas gingivalis (Pg) and Prevotella intermedia(Pi) were determined at baseline, immediatly and one month after the treatment. The results showed a significant reduction of total CFU for both groups immediately after the treatment, but it was better for the Test group. After one month the total CFU average increased but was still below pretreatment levels for both groups. The black pigmented CFU and the level of Aa, Pg e Pi decreased significantly after the treatment but 30 days after there was an increase almost equal to baseline levels for both groups. The Nd:Yag laser associated with convencional treatment promoted bacterial reduction on class II furcation immediately after its application.

    Palavras-Chave: bacteria; laser radiation; lasers; clinical trials

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  • IPEN-DOC 04452

    KOGLER, V.L.; MAIO, M.; LAGE-MARQUES, J.L.; ZEZELL, D.M. . Carbon dioxide laser or cold scalpel on the removal of gingival melanin pigmentation: comparative study. Brazilian Dental Journal, v. 15, Special issue, p. 90-90, 2004.

    Abstract: Melanin pigmentation is the result of melanin granules produced by melanocytes present in the basal layer of the oral epithelium. Gingival physiological melanin pigmentation is symmetric and persistent, may cause esthetic problems especially in individuals with a gummy smile. Various techniques have been described for the removal of melanin pigmentation from the gingival epithelium and partial thin connective tissue, as chemical agents, cryosurgery, surgery and gingival grafts. Recently, lasers systems have been used to coagulate and vaporize cells, promoting controlled gingival ablation. This study compares clinical efficiency to removal gingival melanin pigmentation in 20 patients with dioxide carbon laser, and 20 patients with cold scalpel during 30 days after surgery. A dioxide carbon laser (output = 5W; superpulse = 0,5s; spot size = 2,5mm defocused; focal distance = 5,5cm, Intensity = 102 W/cm2) was irradiated on gingival mucosal surface. Both techniques presented epithelialization in 15 days. Both systems are considered effective for removal melanin pigments. Patient's evaluation with postoperative pain found the carbon dioxide laser technique superior to the cold scalpel one. After 30 days, the repigmentation occured in 45% of the dioxide carbon laser patients, and 80% of the cold scalpel patients.

    Palavras-Chave: carbon dioxide lasers; melanin; pigments; lasers

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  • IPEN-DOC 03452

    FARHART, P.B.A.; TANJI, E.Y.; FARHAT, R.P.; ZEZELL, D.M. ; MIYAKAWA, W.; NOGUEIRA, G.E.C.. Model of thermal and optical effects in dental pulp during the neodymium and diode lasers irradiation. Brazilian Dental Journal, v. 15, Special issue, p. 90-90, 2004.

    Abstract: Applications of high intensity lasers in the enamel and dentine can produce adverse thermal effects into the pulp. Since the evaluation thermal effects into the intact pulp is not a solved problem, extracted teeth models have been used frequently. Current models, however, simulate only tooth thermal properties, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can causes local thermal effects. For this purpose, two models were developed using extracted bovine teeth with their pulp chambers filled with: water (model 1) and with an optical absorbent (model 2). Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: i) up to 11% higher than in the model 1 when the enamel is radiated and ii) up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp). Thus, remaining radiation into the pulp is relevant for the above mentioned lasers and doses.

    Palavras-Chave: biological radiation effects; dentin; dentistry; enamels; laser radiation; temperature dependence

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  • IPEN-DOC 01816

    THEODORO, L.H.; GARCIA, V.G.; ZEZELL, D.M. ; HAYPEK, P.; BACHMANN, L. ; SAMPAIO, J.E.C.. Effect of Er:YAG and diode lasers in the adhesion of blood components and in the morphology of irradiated root surfaces. Brazilian Dental Journal, v. 15, Special issue, p. 89-89, 2004.

    Abstract: The aim of this study was to evaluate in vitro the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94??m) and GaAlAs Diode (808 nm) lasers and these effects on irradiated root surfaces. It was obtained 100 samples of human teeth. They were scaled and divided into five groups of 20 samples each: G1 (Control); G2 -Er:YAG laser (7.6 J/cm2); G3 - Er:YAG laser (12.9 J/cm2); G4 -Diode laser (90 J/cm2) and G5 - Diode laser (108 J/cm2). After these treatments were conducted, 10 samples of each group received a blood tissue, and the reminiscent 10 samples did not receive such treatment. After laboratorial treatments the samples were analysed by scanning electron microscopy. The results have shown that there were no significant differences between the Control Group and the groups treated with Er:YAG laser (p=0,9633 and 0,6229); G4 and G5 were less effective than the Control Group and the Er:YAG laser groups (p<0,01). No proposed treatment increased the adhesion of blood components in a significant way when compared to the Control Group; although the Er:YAG laser did not interfere in the adhesion of blood components it caused more changes on the root surface, while the Diode laser inhibited the adhesion.

    Palavras-Chave: teeth; blood; fibrin; lasers; erbium; in vitro; morphological changes

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  • IPEN-DOC 01757

    EDUARDO, L.R.P.; RIBEIRO, M.S. ; DUARTE, M.; ZEZELL, D.M. . Low level laser therapy in treatment of TMJ and masticator muscles disease: biometrical and pain evaluation. Brazilian Dental Journal, v. 15, Special issue, p. 87-87, 2004.

    Abstract: A sample of 11 patients showing temporomandibular joint disease, in one or both sides, was selected. Clinical examinations were performed on patients to define which side was the most compromised by the disease. Only the worst side was chosen to be treated by the laser therapy. The Laser Unit used was a diode laser (AlGaAs) in which the wavelength was 810 nm (infra-red spectrum). Irradiations were done in tree points of TMJ, with 22,5 J/cm2; two points in the masseter muscle, with 15 J/cm2; and tree points in the temporal muscle, with 7,5 J/cm2. All points were irradiated for 30 seconds. The other side, of lesser complaint received a sham therapy. Treatment was done during two weeks, tree irradiation with 48 hours interval in the first week, and two irradiations with the same interval in the second week. Patients reported improvement in relation to the level of pain, mainly after the forth irradiation, and the level of pain decreased until the last day of treatment. In relation to the degree of mouth opening, the majority of patients showed a significant increase, mainly after the fifth day of irradiation.

    Palavras-Chave: laser radiation; therapy; muscles; jaw; pain

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  • IPEN-DOC 01717

    FREITAS, A.Z. ; ZEZELL, D.M. ; RIBEIRO, A.C.; GOMES, A.S.L.; VIEIRA, N.D. . Imagin carious human dental tissue with three-dimensional optical coherence tomography. Brazilian Dental Journal, v. 15, Special issue, p. 79-79, 2004.

    Abstract: Optical Coherence Tomography (OCT) used in this study, is a new non invasive optical detection technique. The OCT system is based on a Michelson interferometer, that generates a crosssectional image of the teeth with resolution up to 2 microns. The buccal surface from the third molar teeth was used to induce caries like lesions. This surface was coated with an acid resistant nail varnish except a small window. The pH demineralizationremineralization cycling model was used to produce the lesions. This cycle was repeated for 9 days and remained in the remineralizing solution for 2 days. The OCT system was implemented by using an ultrashort pulse laser (Ti:Al2O3@830nm) with 50fs of pulse width and average power of 80mW. The laser beam was focused into the teeth providing a lateral resolution of 10 microns. Image was produced with a lateral and axial scans steps of 10 microns. After analyzing the surface by OCT it was possible to produce a tomogram of dentine-enamel junction and it was compared with the histological image. This OCT system accurately depicts dental tissue and it was able to detect early caries in its structure, providing a powerful contactless high resolution 3D images of lesions.

    Palavras-Chave: teeth; bone tissues; microstructure; caries; three-dimensional calculations; interferometry; optical properties; tomography

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  • IPEN-DOC 01531

    BACHMANN, L. ; DIEBOLDER, R.; HIBST, R.; ZEZELL, D.M. . Changes in chemical composition and collagen structure of dentin tissue after erbium laser irradiation. Brazilian Dental Journal, v. 15, Special issue, p. 78-78, 2004.

    Abstract: The erbium laser light has a great affinity to the water molecule, which is present in great quantity in biological hard tissues. The objective of this work is to identify chemical changes by infrared spectroscopy of irradiated dentin by an Er:YAG - 2.94μm laser. The irradiation was performed with fluences between 0.365 J/cm2 and 1.94 J/cm2. For the infrared analysis a Fourier transform infrared spectrometer was used. After the irradiation were observed: loss of water, alteration of the structure and composition of the collagen and increase of the OH- radical. These alterations can be identified by a decrease of the water and OH- band between 3800-2800 cm-1, bands ascribed to collagen structure between 1400-1100 cm-1. The results show that the erbium laser changes the structure and composition of the organic matrix, OHradical and the water composition in the irradiated dentin.

    Palavras-Chave: dentin; bone tissues; teeth; erbium; lasers

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  • IPEN-DOC 28465

    ETCHEBEHERE, E.; LIMA, M.; PEREIRA, L.; PAGNANO, R.; BORTOLETTI, E. ; MENGATTI, J. ; BRUNETTO, S.Q.; TAKAHASHI, M.; BRUNETTO, E.; OZELO, M.; SANTOS, A.. Knee radiosynovectomy with Sm-153 hydroxyapatite compared to Y-90 hydroxyapatite: initial results of a prospective trial. European Journal of Nuclear Medicine and Molecular Imaging, v. 47, Supplement 1, p. S628-S628, 2020. DOI: 10.1007/s00259-020-04988-4

    Abstract: Aim/Introduction: Introduction: The most common clinical presentation in hemophilia patients consists of hemarthrosis. Various treatment strategies aim to control hemarthrosis to prevent secondary arthropathy, among them, radiosynovectomy with Y-90 hydroxyapatite (90YHA). A few studies have shown a lower efficiency of knee radiosynovectomy with Sm-153 hydroxyapatite (153Sm- HA) compared to 90Y-HA. Purpose: The purpose of this investigation was to assess the efficacy and safety of knee radiosynovectomy with 153Sm-HA compared to 90Y-HA. Materials and Methods: Forty patients were prospectively assigned to undergo knee radiosynovectomy with 153Sm- HA (19 patients) or with 90Y-HA (21 patients). The frequency of hemarthrosis episodes before and after treatment was compared. Results: The response to knee radiosynovectomy stratifying according to radiotracer showed that after 6 months the median response rate with 153Sm-HA was not significantly different from 90Y-HA (87.5% vs 80.9%; p = 0.576). However, after 12 months the median response rate of knee radiosynovectomy with 153Sm-HA was significantly better than with 90Y-HA (87.5% vs 50%; p = 0.037), respectively. The reduction of joint bleeding by at least 50%, after 12 months, was greater in the group of patients treated with 153Sm-HA compared to 90Y-HA (74% vs 52%), respectively. Conclusion: Knee radiosynovectomy with high doses of 153Sm-HA is safe, with an efficiency rate similar that is described in the literature by the 90Y-HA.

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  • IPEN-DOC 28464

    RAMOS, C.; SOUZA, S.; TOBAR, N.; CASTRO, V.; FRASSON, F.; AMORIM, B.; ETCHEBEHERE, E.; LIMA, M.; MENGATTI, J. ; ARAUJO, E. ; PERINI, E. ; SOUZA, C.; LORAND-METZE, I.; SANTOS, A.; DELAMAIN, M.. Comparison of 68Ga-PSMA and 18F-FDG PET/CT uptake in different lymphoma subtypes: preliminary results. European Journal of Nuclear Medicine and Molecular Imaging, v. 47, Supplement 1, p. S41-S42, 2020. DOI: 10.1007/s00259-020-04988-4

    Abstract: Aim/Introduction: Few reports have documented the uptake of radiolabeled Prostate-Specific Membrane Antigen (PSMA) in lymphomas [1,2]. It is not known how PSMA uptake varies among various histological subtypes and how it correlates with 18F-FDG uptake in lymphomas. This study aimed to compare 68Ga-PSMA and 18F-FDG in different lymphoma subtypes. Materials and Methods: Nine randomly selected patients with biopsy-proven lymphoma -median age 43 (32-70) years, 5 female - were submitted to whole-body 18F-FDG and 68Ga- PSMA PET/CT (time interval: 1-6 days between procedures). Lymphoma subtypes included: nodular-sclerosis Hodgkin’s lymphoma (HL; 2 patients); diffuse large B-cell lymphoma (DLBCL; 1); marginal-zone lymphoma (2); MALT lymphoma (ML; 1); follicular lymphoma (FL; 1); lymphoplasmacytic lymphoma (1); and B-cell non- Hodgkin’s lymphoma, unspecified (BCNHL-U; 1). Eight patients were under initial staging, and 1 (HL) with disease relapse after treatment. Two experienced nuclear physicians analyzed the images by consensus. The intensity of tracer uptake was visually classified as marked, moderate or mild. The affected sites (lymph node chains, spleen, diffuse bone marrow involvement and non-lymphatic focal lesions) were counted in both sets of images and their respective maximum SUV (SUVmax) were measured. Results: PSMA PET/ CT was positive in all patients except for one with ML. FDG PET/CT was positive in all patients. At visual analyses, FDG uptake was higher than PSMA uptake in all patients, except for one patient with BCNHL-U (both tracers with similar low-intensity uptake). The intensity of FDG and PSMA uptake was respectively classified as marked in 3/9 and 0/8 patients, moderate in 4/9 and 1/8 and mild in 2/9 and 7/8. One patient (FL) presented a “mismatch” uptake pattern with different parts of an extensive lesion presenting predominant uptake of PSMA or FDG. Brain infiltration in one patient (DLBCL) was more easily identified on PSMA than on FDG images. FDG detected a total of 58/58 and PSMA 43/58 affected sites in all patients with a median SUVmax of respectively 5.4 (2.0-31.1) and 2.8 (1.3-5.4), p<0.0001. The median SUVs of the 43 lesions with uptake of both tracers was respectively 5.5 (2.0-28.9) and 2.8 (1.3-P5.4) for FDG and PSMA, p<0.0001. Conclusion: Distinct lymphoma subtypes present PSMA uptake, with less intensity than FDG uptake. Although PSMA uptake is usually mild, several lymphoma subtypes might cause false-positive results in PSMA PET/CT performed to assess prostate cancer.

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  • IPEN-DOC 28463

    SOUZA, S.; DELAMAIN, M.; TOBAR, N.; CASTRO, V.; FRASSON, F.; AMORIM, B.; ETCHEBEHERE, E.; MARIANA, K.; MENGATTI, J. ; ARAUJO, E.B. ; PERINI, E. ; SOUZA, C. de; SANTOS, A.; LORANT-METZE, I.; RAMOS, C.. Comparison of 68ga-psma and 18f-fdg pet/ct uptake in different lymphoma. Hematology, Transfusion and Cell Therapy, v. 42, Supplement 1, p. S48-S48, 2020. DOI: 10.1016/j.htct.2020.09.086

    Abstract: Objective: Few reports have documented the uptake of radiolabeled Prostate-Specific Membrane Antigen (PSMA) in lymphomas.1, [2] It is not known how PSMA uptake varies among various histological subtypes and how it correlates with 18F-FDG uptake in lymphomas. This study aimed to compare 68Ga-PSMA and 18F-FDG in different lymphoma subtypes. Methodology: Nine randomly selected patients with biopsy-proven lymphoma with a median age 43 (32–70) years, 5 female – were submitted to whole-body 18F-FDG and 68Ga – PSMA PET/CT (time interval: 1–6 days between procedures). Lymphoma subtypes included: nodular-sclerosis Hodgkin's lymphoma (HL; 2 patients); diffuse large B-cell lymphoma (DLBCL; 1); marginal-zone lymphoma (2); MALT lymphoma (ML; 1); follicular lymphoma (FL; 1); lymphoplasmacytic lymphoma (1); and B-cell non-Hodgkin's lymphoma, unspecified (BCNHL-U; 1). Eight patients were under initial staging and 1 (HL) with disease relapse after treatment. Two experienced nuclear physicians analyzed the images by consensus. The intensity of tracer uptake was visually classified as marked, moderate or mild. The affected sites (lymph node chains, spleen, diffuse bone marrow involvement and non-lymphatic focal lesions) were counted in both sets of images and their respective maximum SUV (SUVmax) were measured. Results: PSMA PET/CT was positive in all patients except for one with ML. FDG PET/CT was positive in all patients. At visual analyses, FDG uptake was higher than PSMA uptake in all patients, except for one patient with BCNHL-U (both tracers with similar low-intensity uptake). The intensity of FDG and PSMA uptake was respectively classified as marked in 3/9 and 0/8 patients, moderate in 4/9 and 1/8 and mild in 2/9 and 7/8. One patient (FL) presented a “mismatch” uptake pattern with different parts of an extensive lesion presenting predominant uptake of PSMA or FDG. Brain infiltration in one patient (DLBCL) was more easily identified on PSMA than on FDG images. FDG detected a total of 58/58 and PSMA 43/58 affected sites in all patients with a median SUVmax of respectively 5.4 (2.0–31.1) and 2.8 (1.3–5.4), p < 0.0001. The median SUVs of the 43 lesions with uptake of both tracers was respectively 5.5 (2.0–28.9) and 2.8 (1.3–5.4) for FDG and PSMA, p < 0.0001. Conclusion: Distinct lymphoma subtypes present PSMA uptake, with less intensity than FDG uptake. Although PSMA uptake is usually mild, several lymphoma subtypes might cause false-positive results in PSMA PET/CT performed to assess prostate cancer.

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  • IPEN-DOC 28462

    ANGELOCCI, L. ; NOGUEIRA, B.R. ; SOUZA, C.D. de ; ZEITUNI, C.A. ; ROSTELATO, M.E.C.M. . Assessing Ir-192 as an alternative to I-125 in ophthalmic treatment. Radiotherapy and Oncology, v. 152, Supplement 1, p. S735-S736, 2020. DOI: 10.1016/S0167-8140(21)01402-X

    Abstract: Purpose or Objective: Brachytherapy sources for ocular melanoma usually contain Co-60, I-125, Pd-103 or Ru/Rh-106 as radionuclides. Ir-192 is not a preconized radioactive material for this purpose, although it is used for other brachytherapy applications. Higher mean energy from Ir-192 emission (ca. 380 keV) may be a reason for the preference of I-125 (35 keV) or Pd-103 (21 keV) over it, since low penetration is desired on the small structures of the human eye. This is not, however, an excluding criterion, considering Co-60 and Ru/Rh-106 have even higher mean energies. The demand in Brazil for lower-cost seeds to treat ocular melanoma lead to the development of an Ir-192 seed to make treatment more accessible, but since it is not used as an ophthalmic brachytherapy source, before its dosimetry is considered, one should care about the possibility of using it over more stablished materials. Considering this, the aim of this work is to assess the possibility of using Ir-192 seeds as ophthalmic brachytherapy sources by comparing some dosimetric parameters of a new seed model with the most stablished I-125 seed in literature, OncoSeed 6711. Material and Methods: As an initial study on the topic, this work relies only on Monte-Carlo simulations using MCNP4C transport code. Parameters analyzed are air-kerma strength, dose-rate constant and depth-dose curve, attention given to points within the human eye dimensions. The medium considered was homogeneous water, as it is a good approximation to the eye tissues in terms of composition and density and allows for future comparisons with TG-43 based calculations. OncoSeed 6711 is not produced anymore, but its long term as the reference source for dosimetry was considered. A 20 mm COMS ophthalmic applicator was also modeled and considered to be fully loaded with each seed model to compare the same parameters at a realistically clinical approach. Results: As expected, due to the higher energy of the Ir-192 emission spectrum, dose fall-off on the transversal axis of the seeds is less pronounced for the new seed model. The steeper dose gradient for I-125 is also visible on the doserate constant value. The effect of using a COMS applicator only strengthens this characteristic. Depth-dose curves were calculated up to the distance of 5 cm, both for a single seed and for an applicator fully loaded with 24 seeds. All the eye components relevant for dosimetry are located within this range, like the cells of the crystallin and the optical nerve. Conclusion: If one expects to use Ir-192 as an alternative to I-125 in ophthalmic cancer treatment, at least the dosimetry following TG-43 protocol should be carried with utmost attention, as undesirable dose to healthy nearby tissues is unavoidable. Crafting a different applicator most suited for this radionuclide is a possibility that can be taken into account. Another recommendation is to go beyond TG-43 water-based protocol and actually estimate dose to relevant eye components.

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  • IPEN-DOC 28461

    BELLEZZO, M. ; FONSECA, G.P.; VONCKEN, R.; VERRIJSSEN, A.; VAN BEVEREN, C.; ROELOFS, E.; YORIYAZ, H. ; RENIERS, B.; VAN LIMBERGEN, E.J.; BARBEE, M.; VERHAEGEN, F.. MAASTRO applicator, a novel rectal applicator for contact brachytherapy with 192Ir HDR sources. Radiotherapy and Oncology, v. 152, Supplement 1, p. S1102-S1103, 2020. DOI: 10.1016/S0167-8140(21)01990-3

    Abstract: Purpose or Objective: The standard care for rectal cancer includes surgery, which may be avoided if complete response is achieved, e.g. with chemoradiotherapy (EBCRT) or external beam radiotherapy EBRT, adopting a watch and wait strategy. Studies report a local regrowth reduction from 30% (EBCRT alone) to 11% when EBCRT is associated with a radiation boost using 50 kV x-rays (CXB), technique that allows a high dose delivery to a highly selective volume, allowing preservation of organs at risk (OAR) and low toxicity. However, CXB is not widely adopted due to its low costeffectiveness. Hence, the MAASTRO applicator was developed to deliver a dose distribution similar to those generated by CXB devices, but using HDR 192Ir sources, as a cost-effective alternative to CXB, with possibility of integration to treatment planning systems (TPS). Material and Methods: Fig 1-a shows the applicator design, a cylindrical applicator with 5 channels and a slanted edge, using its tip. Results: Due to the applicator geometry, the most distal position of the source in each channel doesn’t reach the sharp edge of the applicator, resulting in an effective treatment surface (high dose region shown in Fig 1 a and b) of approximately 20 x 20 mm2, which is smaller than the contact surface. The resulting dose falloff is steeper than the one resulting from the P50 with a 22 mm applicator. With the dose falloff normalized at 2mm, the relative dose values delivered at depths of 0, 2, 5 and 10 mm are, respectively, 130, 100, 70 and 43% for the P50 and 140, 100, 67 and 38% for the applicator. The time required to deliver an average dose of 32 Gy to the treatment surface of the applicator is 5m30s for a 40700 U source (new source) and 8m30s for a 20350 U source (source to be replaced), including the time required to perform obstruction verification before irradiation. The applicator delivers a high dose to a small target volume while the lateral shielding spares normal tissues in all directions other than the contact surface. Conclusion: The MAASTRO applicator was designed to deliver dose distributions similar to those of CXB devices using 192Ir HDR sources. The applicator has the advantage of TPS integration, increasing the degrees of freedom to modulate the dose distribution.

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  • IPEN-DOC 27993

    ZANINI, NATHALIA ; ZAMATARO, CLAUDIA B. ; RABELO, THAIS F. ; JUVINO, AMANDA C. ; KUCHAR, NIELSEN G. ; CASTRO, PEDRO ; ANA, PATRICIA da; ZEZELL, DENISE . Analysis of ceramic laminates removal with Er,Cr:YSGG laser by optical coherence tomography. Photobiomodulation, Photomedicine, and Laser Surgery, v. 37, n. 10, p. A22-A22, 2019. DOI: 10.1089/photob.2019.29013.abstracts

    Abstract: Porcelain laminated veneers have been widely used. For wear of hard tissue such as enamel and dentin, the diamond rotary instrument is the most traditional, but the laser has become recently used to remove aesthetic facets. Optical coherence tomography (OCT) used as an optical biopsy, is important for morphological analysis and attenuation coefficient is related to the property of the photons to be scattered by the samples. After approval by the Ethics Committee, the present study investigated the detachment of 30 ceramic E-max fragments cemented in human dental enamel of dimensions 3mm x 3mm x 0.7mm with 3 types of resin cements, RelxY Veneer, Relx U200 and Variolink Veneer. The samples (Enamel + Ceramic Fragment) were randomly distributed in the 3 groups and cemented according to the manufacturer. After that, they were prepared for irradiation with the Er,Cr: YSSG laser under predetermined conditions (3.5 and 3W, 20Hz, 60% water and 40% air flow). OCT analysis was done before and after irradiation. We observed that themorphological changes of the enamel surface showed an increased surface area due to the cement remaining in the enamel.We concluded that the Er, Cr: YSGG laser, when used in the irradiation protocol tested, seems to be a safe tool for the removal of laminates.

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  • IPEN-DOC 27992

    RABELO, THAIS F. ; ZAMATARO, CLAUDIA B. ; ZANINI, NATHALIA ; JUVINO, AMANDA C. ; KUCHAR, NIELSEN G. ; CASTRO, PEDRO A.A. ; ZEZELL, DENISE M. . Removal of laminates with Er,Cr:YSGG laser from dental enamel submitted to gamma radiation. Photobiomodulation, Photomedicine, and Laser Surgery, v. 37, n. 10, p. A21-A21, 2019. DOI: 10.1089/photob.2019.29013.abstracts

    Abstract: Background: Modern Dentistry is characterized by the search for aesthetic perfection in the smile. Many efforts are made regarding procedures related to manufacturing, cementing, maintenance and removal of ceramic laminates. The laser removal of laminates has become more frequent when the aesthetical procedures needs to be replaced. On the other hand, the head and neck cancer treatment causes comorbidities in the buccal environment when laminates are in place. Objective: To evaluate in vitro the removal of ceramic fragments by means of Er,Cr:YSGG laser irradiation, after gamma radiation. Methods: 20 Lithium disilicate veneers were cemented with Variolink to human dental enamel and then samples were irradiated with 0.07 kGy. After gamma irradiation, the laminates removal with Er,Cr:YSGG laser was performed. The control group was not subjected to gamma radiation. Dental enamel samples were analyzed by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FTIR) and Surface Microhardness Loss (SMH). Results: SEM has shown that less cement was found after removal of the facets in gamma irradiated group when compared to the control. For both groups there was alteration of the SMH possibly due to the use of the adhesive system. When performed intra group analysis, the sample being its own control of baseline in the FTIR analysis, there were no band shifts or formation of new compounds on the surface of human dental enamel. Conclusions: The Er,Cr:YSGG laser is an effective alternative for laminates removal in human dental enamel even when it is subjected to gamma radiation.

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  • IPEN-DOC 27991

    KUCHAR, NIELSEN G. ; ZAMATARO, CLAUDIA B. ; RABELO, THAIS ; JUVINO, AMANDA ; ZANINI, NATHALIA ; CASTRO, PEDRO ; ZEZELL, DENISE M. . Calcium analysis of gamma sterilized human dentin submmited to Er,Cr:YSGG laser irradiation. Photobiomodulation, Photomedicine, and Laser Surgery, v. 37, n. 10, p. A18-A19, 2019. DOI: 10.1089/photob.2019.29013.abstracts

    Abstract: Studies report that gamma radiation changes the oral cavity of patients submitted to radiotherapy. These changes include xerostomia, resulting in an unsaturation of calciumand phosphate in the oral cavity. However, human enamel samples isolated from the altered oral environmentwhen irradiatedwithgamma radiation at doses of up to 25kGy (much higher than radiotherapy doses) were shown to have undergone no changes in molecular hardness or micro surface. After approval of the Research Ethics Committee, 20 human dentin samples were evaluated before and after irradiation, split randomly into control group (n = 10) and irradiated group (n = 10) treated with 25.0 kGy at the Co60 multipurpose irradiator and irradiated with Er,Cr:YSGG laser in the parameters: 8.5 J/cm2 in the Fourier Transform Infrared Spectroscopy (FTIR), % surface Microhardness loss and Scanning Electron Microscopy (SEM). At the end, acidic biopsies were performed to quantify the concentration of calcium present in the samples. In the results of FTIR analysis differences were found only in the bands of organic content and in the inorganic content, difference were not found between before and after irradiations. The EDS and % Surface Microhardness loss analysis corroborates these findings, as well as no significant loss of the Calcium content before and after their radiation with Co60 at 25 kGy and with the Er,Cr:YSGG laser. These findings lead us to a new hypothesis of behavior of the hydroxyapatite crystal submitted to the gamma irradiation.

    Palavras-Chave: teeth; radiotherapy; gamma radiation; radiation doses; calcium

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  • IPEN-DOC 27990

    ZAMATARO, CLAUDIA B. ; RABELO, THAIS F. ; ZANINI, NATHALIA ; JUVINO, AMANDA C. ; KUCHAR, NIELSEN G. ; CASTRO, PEDRO A.L. ; ANA, PATRICIA A. da; ZEZELL, DENISE M. . Er,Cr:YSGG laser irradiation associated to fluoride for in situ model using gamma sterilized dentin and enamel. Photobiomodulation, Photomedicine, and Laser Surgery, v. 37, n. 10, p. A13-A13, 2019. DOI: 10.1089/photob.2019.29013.abstracts

    Abstract: The in situ intraoral model uses human dental enamel samples (HDE) in order to analyse the de-remineralization processes using the buccal environment without interfering into the patients’ natural dentition. The main ethical concern from this model is the biosafety. Gamma radiation is a very efficient sterilization method that is not expected to alter the mineral content of the hard tissues, avoiding biases in the results. Thus 40 HDE samples were irradiated through a source of 60Co multipurpose irradiator aiming complete sterilization (25 KGy/h) with the purpose of accumulating the native plaque on them at an in situ study. An Er,Cr:YSGG laser was used alone and in combination with the topical applications of: 1-dentifrice (1,100 lg F-/g) or 2-APF (12,300 lg F-/g). Morphological analyses were performed by scanning electron microscopy (SEM), determination of alkali-soluble fluoride concentration by specific ion electrode and microhardness determination. Then, the 15 volunteers used palatal devices containing previously treated HDE samples and remained using F dentifrice. The FTIR findings established that gamma radiation could be used aiming HDE sterilization. The Knoop hardness number was within the range of that of natural dentin of human origin. X-ray fluorescence shows that irradiated dentin has great similarity with natural dentin from the point of view of chemical composition. SEM analyses showed that there was no thermal damage or interprismatic morphological changes in the hydroxyapatite structure of human dental dentin outside the buccal environment when using doses of gamma irradiation up to 25 kGy.

    Palavras-Chave: teeth; enamels; sterilization; lasers; irradiation

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  • IPEN-DOC 27989

    JUVINO, AMANDA C. ; ZAMATARO, CLAUDIA B. ; RABELO, THAIS F. ; KUCHAR, NIELSEN G. ; ZANINI, NATHALIA ; CASTRO, PEDRO ; ZEZELL, DENISE . In vitro determination of the critical pH demineralization of human dental enamel irradiated with Nd:YAG laser associated with fluoridated product. Photobiomodulation, Photomedicine, and Laser Surgery, v. 37, n. 10, p. A8-A9, 2019. DOI: 10.1089/photob.2019.29013.abstracts

    Abstract: The use of fluoride products associated with high intensity laser irradiation are beneficial for dental caries prevention because it increases the surface area, improving the formation of fluorapatite (FA), which gives greater acid-resistance of enamel against bacterial acids. The objective of this study is to determine the critical pH of dental enamel treated with acid fluoride phosphate 12,300 lF-/g (APF) and Nd:YAG laser 84 J/cm2, as there is no precedent to determine this pH. The study consisted of 4 groups (n = 15): G1: Negative Control; G2: APF; G3: Nd:YAG; G4: APF + Nd:YAG. Each group was randomized into three subgroups (n = 5) for pH cycling. The cycling was designed to simulate three conditions: below critical pH of enamel hydroxyapatite (pH 5.0); pH below critical for hydroxyapatite and fluorapatite (pH 4.5); condition further below the critical situation to investigate extent of acid resistance of the enamel (pH 4.0). The samples were analyzed by scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR) and solutions were quantified fluoride (specific ion electrode) and phosphate (colorimetric method). In SEM and FTIR (phosphate band) at pH 5, only the APF and APF + Nd:YAG groups did not present demineralization. At pH 4.5, only the APF + Nd:YAG group was integrated. At pH 4, APF + Nd:YAG showed signs of mild demineralization while the other groups showed aggressive signals. It is concluded that the irradiated fluorapatite has critical dissolution pH different from fluorapatite formed only with the application of fluorine.

    Palavras-Chave: teeth; enamels; fluorides; phosphates; ph value; laser radiation

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  • IPEN-DOC 27968

    CARDOSO, ELISABETH C.L. ; PARRA, DUCLERC F. ; SCAGLIUSI, SANDRA R. ; LUGAO, ADEMAR B. . Influence of particle size of bio-calcium carbonate used as reinforcement of PBAT/PLA bio-based foams compatibilized with ionizing radiation. Journal of Bioremediation & Biodegradation, v. 10, p. 42-42, 2019.

    Abstract: Bio-filler from eggshells as reinforcement of bio-based polymers are based on their principle benefits such as good strength and stiffness besides being an environmental friendly, degradable and renewable material. Eggshell is an agricultural waste largely considered as garbage and discarded mostly because it contributes to pollution. Biodegradable polymers as PLA (poli-lactic acid) and PBAT (butylene adipate co-terephthalate) are thermoplastics which can be processed using most conventional polymer processing methods. PLA is high in strength and modulus (63 MPa and 3.4 GPa, respectively) but brittle (strain at break 3.8%) while PBAT is flexible and tough (strain at break ~710%). In order to reduce interfacial tension exhibited by PLA/PBAT blend, compatibilization is fundamental: herein it was used as compatibilizing agent PLA previously e-beam irradiated at 150 kGy: ionizing radiation induces compatibilization by free radicals, improving the dispersion and adhesion of blend phases, without the use of chemical additives and at room temperature. PLA/PBAT, 65/35 blend with bio-filler, from avian eggs, of 38 and 75 µm particle size were prior homogenized in a co-rotating twin-screw extruder and further foamed in a mono-screw extruder, by using CO2 as Physical Blowing Agent (PBA). Characterizations involved: Melt Index, DSC, TGA, FTIR, SEM, XRD and mechanical essays.

    Palavras-Chave: calcium carbonates; biodegradation; eggs; polymers; fillers

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  • IPEN-DOC 27967

    PARRA, DUCLERC F. ; SILVA, ORELIO L. da ; KOMATSU, LUIZ G. ; CARDOSO, ELIZABETH C.L. ; LUGAO, ADEMAR B. . Nanocomposites foams of polypropilene modified by ionizing radiation containing CaCo3/ag° nanoparticles of bio-calcium carbonate-study of bactericidal effect. Journal of Bioremediation & Biodegradation, v. 10, p. 41-41, 2019.

    Abstract: This paper presents a study of high melting strengh polypropylene (HMSPP) foams by gamma irradiation with insertion of silver nanoparticles (AgNPs) adsorbed in carrier of CaCO3 (natural source) aiming bactericidal effect. The use of silver (Ag°) gives important antibacterial property since silver is highly toxic against bacterae. The HMSPP matrix was processed in a twin screw extruder under CO2 atmosphere and polypropylene nanocomposites (HMSPP-AgNC) were obtained in different concentrations of silver. The material was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), cytotoxicity assay and reduction colony-forming-unit (CFU). The analyzed foams showed spherical clusters and homogeneous regions with good distribution of the silver nanoparticles. Furthermore, the HMSPP@AgNCs foams exhibited a antibacterial efficiency against E. coli and S. aureus due to the presence of the biocidal silver nanoparticles.

    Palavras-Chave: germicides; sterilization; foams; polypropylene; gamma radiation; calcium carbonates

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  • IPEN-DOC 27820

    PETERSEN, ALAN; TACCHEO, STEFANO; MIROV, SERGEY; NILSSON, JOHAN; PASK, HELEN; SARACENO, CLARA; WETTER, NIKLAUS ; WU, RUIFEN. Focus issue introduction: Advanced Solid-State Lasers 2020. Optics Express, v. 29, n. 6, p. 8365-8367, 2021. DOI: 10.1364/OE.423636

    Abstract: This Joint Issue of Optics Express and Optical Materials Express features 15 articles written by authors who participated in the international online conference Advanced Solid State Lasers held 13–16 October, 2020. This review provides a summary of the conference and these articles from the conference which sample the spectrum of solid state laser theory and experiment, from materials research to sources and from design innovation to applications.

    Palavras-Chave: lasers; solid state lasers; radiation sources; meetings

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  • IPEN-DOC 27819

    PETERSEN, ALAN; TACCHEO, STEFANO; MIROV, SERGEY; NILSSON, JOHAN; PASK, HELEN; SARACENO, CLARA; WETTER, NIKLAUS ; WU, RUIFEN. Focus issue introduction: Advanced Solid-State Lasers 2020. Optical Materials Express, v. 11, n. 4, p. 952-954, 2021. DOI: 10.1364/OME.423641

    Abstract: This Joint Issue of Optics Express and Optical Materials Express features 15 articles written by authors who participated in the international online conference Advanced Solid State Lasers held 13–16 October, 2020. This review provides a summary of the conference and these articles from the conference which sample the spectrum of solid state laser theory and experiment, from materials research to sources and from design innovation to applications.

    Palavras-Chave: lasers; solid state lasers; radiation sources; meetings

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  • IPEN-DOC 27604

    PARRA, DUCLERC F. ; SANTOS, VINICIUS J. dos ; TAMIÃO, ANGELICA . Development of poly (n-vinyl-2-pyrrolidone) hydrogels containing nanosilver and laponite clay for modulation of neomycin. Journal of Astrophysics & Aerospace Technology, v. 8, n. 2, p. 3-3, 2020.

    Abstract: These Biomaterials widely used in biomedicine as wound dressings are composed by hydrogels. They offer ideal conditions for wound treatment, such as maintaining the wound environment humid, autolytic debridement, accelerated healing, ability to absorb large amounts of fluids without losing their physical integrity, drug release in a controlled manner protecting infected wounds that are constantly exposed to environment contaminated with microorganisms. These dressings are formed by one or more polymeric components which, when cross-linked, form three-dimensional networks. They have a high degree of flexibility that is very similar to natural living tissues. The general objective of this work was to synthesize by radiation hydrogel membranes containing PVP, PEG, agar, RD laponite in a neomycin and nanosilver release system that promotes a synergistic action between these two antimicrobial agents. Membranes with different concentrations of polymer matrix / clay were produced by irradiation at a dose of 25 kGy of gamma 60Co source, and characterized by techniques: swelling analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile tests, parallel plate rheometry. It can be seen that G 'and G "are approximately parallel within the studied range. G 'is greater than G' 'and both showed little frequency dependence. This performance is the expected for the gels, in which the elastic behavior of the sample predominates over its viscous behavior. The clay-polymer interactions increases gel cross-linking, which provides an increase in their mechanical properties. In parallel, nanoparticles of silver coupled to clay (Laponite) were synthesized in which their properties were verified by means of UV-Vis, MET, ICP-OES and microbiological activity. The study of the microbiological activity of AgNPs-Laponite nanoparticles on the reduction of microorganisms in culture indicated that most of the nanoparticles, synthesized from the reduction of silver ions on the surface of Laponite, have activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans.

    Palavras-Chave: wounds; hydrogels; pvp; healing; biological recovery

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  • IPEN-DOC 27563

    CARDOSO, ELIZABETH C.L. ; PARRA, DUCLERC F. ; SCAGLIUSI, SANDRA R. ; LUGAO, ADEMAR B. . Study of PBAT/PLA bio-based blends reinforced with chicken eggshell nano powder compatibilized with ionizing radiation. Astrophysics & Aerospace Technology, v. 8, n. 2, p. 11-11, 2020.

    Abstract: Eggshell is a solid waste, with production of several tons per day and it is mostly sent to landfills at a high management cost. A few used of eggshell include: fertilizing the garden, cleaning pots and pans, seed starter, feeding birds, making bone broth, etc… Nevertheless, chicken eggshell biowaste has recently been used to substitute calcium carbonate (CaCO3), due to its reinforcing property and low price. It is economically viable to transform eggshell waste to acquire new values, transforming it into a bioplastic: a biodegradable polymer made from bio-mass. The surprising strength of eggshells endorses their application for reinforcement of biodegradable polymers herein studied: PLA (poly-lactic acid) and PBAT (butylene adipate co-terephthalate). PLA is derived from renewable sourced: polylactic acid plastics are sturdier and capable to be blend with conventional petroleum polymers; nevertheless, they exhibit a narrow process window and low thermal stability, besides an inherent high cost. PBAT, as PLA, is a biodegradable aliphatic polyester, although a synthetic polymer based on fossil resources. By incorporating PBAT in PLA it is expected to improve flexibility of PBAT/PLA blend. Previous studies using PBAT/PLA, 50/50 blends containing 15% of chicken eggshell 125 µm improved mechanical behavior of net blends: values for both force and strain practically doubled, proving the effective reinforcement action of calcium carbonate extracted from eggshells. Conventional polymer processing methods can be used in both PLA and PBAT compositions. Due to common incompatibility between PLA and PBAT, considering their extreme glass transition temperatures: 62 º C and – 30 º C, respectively, it is required a compatibilizer to accomplish or increase their interaction. Herein it was used PLA previously e-beam radiated at 150 kGy, as compatibilizing agent: ionizing radiation induces compatibilization by free radicals, improving the dispersion and adhesion of blend phases, without the use of chemical additives and at room temperature. Herein there were prepared bio-composite PBAT/PLA 82/18 blends with 2.5, 5.0 and 10.0 % of eggshell nano-powder, 161 nm, in average, and 5.0 % of PLA 150 kGy e-beam radiated were homogeneized in a co-rotating twin-screw extruder. Subsequent investigations included: Differential Scanning Calorimeter (DSC), Thermal Gravimetric Analysis (TGA), Fourier Transmittance Infrared (FTIR), X-Ray Diffraction (XRD), Tensile Strength and Elongation at Break

    Palavras-Chave: eggs; chickens; fertilizers; solid wastes; ionizing radiations; nanopowders

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  • IPEN-DOC 27446

    VILLAS BOAS, CRISTIAN A.W. ; MENGATTI, JAIR ; PASSOS, PRISCILA ; VIEIRA, DANIEL ; ARAUJO, ELAINE B. de . In vitro response of 177Lu-PSMA-617 with two different specific activities. Journal of Nuclear Medicine, v. 61, supplement 1, 2020.

    Abstract: Introduction: PSMA-617 radiolabeled with lutetium-177 has shown good results in compassionate studies around the world. Being a receptor-specific radiopharmaceutical, the specific activity (SA) of the preparation may represent an important factor for therapeutic efficacy. Lutetium-177 can be produced by two different routes: with ytterbium-176 (Non-carrier-added or NCA) and with lutetium-176 (Carrier-added or CA). The SA (MBq/ug) of the labeled PSMA varies accordingly to each lutetium. For NCA lutetium, the radiolabeling procedure is based on the SA of 74 MBq/ug. When the radiolabeling is performed with CA lutetium, SA is determined by the molar ratio of 2.1:1 (PSMA moles/lutetium moles declared in the certificate), resulting in lower SA than NCA. This work evaluated the influence of specific activity of 177Lu-PSMA-617 on in vitro specific binding assays (saturation, competition and internalization). Materials and Methods: Radiolabeling of PSMA-617 (ABX, Germany) with lutetium-177 was performed in heating block at 90°C for 30 minutes with sodium ascorbate (0.5 M pH 4.7) as buffer. For NCA lutetium (JSC, Russia) the radiopharmaceutical specific activity was 74 MBq/ug. For CA lutetium (IDB, Netherlands), the specific activity was 41 MBq/ug. The radiochemical purity was analyzed with HPLC. For all experiments, 6-well plates were used for adherence cells with 200,000 LNCaP per well. Molar concentration of saturation curves experiments were 0.01; 0.05; 0.6; 1.5; 3.0 and 3.5 for CA lutetium and 0.1; 0.6; 1.5; 2.0; 2.5 and 3.0 for NCA lutetium. After 1 hour of incubation at 8 ºC, supernatant was removed, then washed with PBS (phosphate buffer saline) and finally cells were burst with NaOH 1 M, and activity was measured in gama counter; the experiments were performed in octuplicate. Competition experiments were performed adding in all wells 5 nM of radiolabeled PSMA-617 and in the competition well (non-specific binding) were added an excess of 15 times (76 ug) of non radiolabeled PSMA-617. After 1 hour of incubation at 8 ºC, supernatant was removed, then washed with PBS and finally cells were burst with NaOH 1 M, and activity was measured in gama counter, these experiments were performed in triplicate. The specific binding was obtained by the difference between total binding and non-specific binding. Internalization experiments were performed at Kd of NCA and CA lutetium. After 1 hour of incubation at 37 ºC, supernatant was removed, washed with PBS, then washed again with 0.05 M glycine solution pH 2.8 and finally cells were burst with NaOH 1 M. Activity was measured in gama counter, these experiment were performed in sextuplicate. Results and discussion: The radiochemical purity were 98% and 99% for labeling with NCA and CA lutetium, respectively. Saturation curve assay with NCA lutetium shown a Kd of 0.7 ± 0.15 nM and a Bmax of 857 ± 55.79 pMol/ng, and with CA lutetium resulted in a Kd of 1.71 ± 0.45 nM and a Bmax of 1156 ± 113.8 pMol/ng. The variation between both Kd curves were statistically different (P value = 0.0058). Competition assay demonstrated an effective blocking for both types of lutetium, for NCA unpaired T test shown a P value of 0.0011. For CA lutetium, the unpaired test disclosed a P value of 0.0258. The comparison between both results revealed a P value of 0.01 at the specific binding. Internalization assay shown for both types of lutetium similar results, 27.1 ± 2.45% and 30.6 ± 4.97%, for CA and NCA lutetium, respectively, and was not statistically significant (P value = 0.17). Conclusions: These experiments demonstrated that the type of lutetium (CA or NCA) directly affects in vitro binding of 177Lu-PSMA-617 to receptors expressed in LNCaP cells. It was statistically demonstrated that the higher specific activity of 177Lu-PSMA-617, more radiolabeled peptide can bind to cells at saturation and competition assays.

    Palavras-Chave: radiopharmaceuticals; lutetium 177; therapy; in vitro

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  • IPEN-DOC 27445

    COELHO, GUILHERME R.; PREZOTTO NETO, JOSE P. ; BARBOSA, FERNANDA C.; SANTOS, RAFAEL S.; BRIGATTE, PATRICIA; SPENCER, PATRICK J. ; SAMPAIO, SANDRA C.; D'AMELIO, FERNANDA; PIMENTA, DANIEL C.; SCIANI, JULIANA M.. Hypanus americanus mucus: a new point of view about stingray immunity and toxins. Toxicon, v. 177, Supplement 1, p. S34-S34, 2020. DOI: 10.1016/j.toxicon.2019.12.047

    Abstract: Fish skin plays important biological roles, such as the control of the osmotic pressure gradient, protection against mechanical forces and microorganism infections. The mucus, on the other hand, is a rich and complex fluid, important for the fish acting as innate immunity system, swimming and nutrition. The elasmobranch epidermis is characterized mainly by mucus secretory cells, and marine stingrays have already been described to present secretory glands spread throughout the body. Little is known about the biochemical composition of the stingray mucus, but recent studies denoted the importance of mucus in the envenomation process. Stingrays venom are largely studied due the human medical importance of envenoming caused by sting puncture, that evolve with local inflammation and necrosis, and these toxic events can be correlated to the chemical composition of the sting skin, according to the literature. Aiming to analyse the mucus composition, a new non-invasive mucus collection method was developed that focused on peptides and proteins, and biological assays were performed to analyze preliminary toxic and immune activities of the Hypanus americanus mucus. Pathophysiological characterization showed the presence of peptidases on mucus, as well that the induction of edema and leukocyte recruitment in mice. The fractionated mucus improved phagocytosis on macrophages and showed antimicrobial activity against T. rubrum, C. neoformans and C. albicans in vitro. The proteomic analyses showed the presence of immune-related proteins like actin, histones, hemoglobin, and ribosomal proteins. This protein pattern is similar to those reported for other fish mucus and stingray venom. This is the first report depicting the Hypanus stingray mucus composition, highlighting its biochemical composition and importance for the stingray immune system and the possible role on the envenomation process.

    Palavras-Chave: fishes; skin; venoms; therapeutic uses

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  • IPEN-DOC 27444

    SABINO, CAETANO P.; SELLERA, FABIO P.; SALES-MEDINA, DOUGLAS F.; MACHADO, RAFAEL R.G.; DURIGON, EDISON L.; FREITAS-JUNIOR, LUCIO H.; RIBEIRO, MARTHA S. . UV-C (254 nm) lethal doses for SARS-CoV-2. Photodiagnosis and Photodynamic Therapy, v. 32, p. 1-2, 2020. DOI: 10.1016/j.pdpdt.2020.101995

    Palavras-Chave: sterilization; germicides; radiation doses; ultraviolet radiation; coronaviruses

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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

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O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.