INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES
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Navegação Eventos - Resumos por Agências de fomento "Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)"

Navegação Eventos - Resumos por Agências de fomento "Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)"

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  • IPEN-DOC 26803

    SAEKI, MARGARIDA J.; GARCIA, JOÃO I.M.M.; FERNANDES, CELIO J.C.; ROSSI, MARIANA C.; SILVA, WILLIAM de M.; MARTINEZ, LUIS G. ; ZAMBUZZI, WILLIAN F.. Characterization of titanium surface modified by calcium titanate. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Coatings based on apatite and others that contain calcium play an important role for the osseointegration with the implant. It is believed that released calcium induces a specific biological response to the living tissue establishing a stable chemical bonding between formed bone and implants. The mechanical anchorage of implants also depends on the surface structure and morphology. In this work, the titanium surface was modified by calcium titanate, which was deposited by sol-gel method combined to the dip coating technique followed by heat treatments. Two different emersion rate (5 and 10 cm/min) were used as well as the number of coatings were varied. The temperature of this treatment was established based on the results of the thermal analysis (TG/DTA). The surfaces were characterized by X-ray diffractometry (DRX), Scanning Electron Microscopy (SEM) and water contact angle measurement. The corrosion behavior of modified surfaces was evaluated by electrochemical method (polarization curves) in balanced saline Hanks solution. Finally, biological test was carried out by the analysis of cellular viability and adhesion of MC3T3-E1 (subclone 4), mouse pre-osteoblastic cells (ATCC CRL-2593), using MTT and crystal violet assays, respectively, after 24h incubation at 37oC in 5% CO2 atmosphere. The coating consists of anatase TiO2 (PDF 21-1272) and calcium titanate (CaTiO3, PDF 43-226). SEM analysis showed that homogeneous films with 0.8μm of thickness are provided when they are prepared by only one immersion and that the films increase the resistence to corrosion. The coating increases the wettability as the water contact angle decreases from 90o±10o for cp Ti (low interstitial titanium) to 34 o±5o. The biological test shows that the modifications do not interfere on the osteoblast viability and adhesion, however, the morphological analysis of preosteoblasts cultured on the modified Ti-surface by SEM shows that the coatings promote a cell spreading.

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  • IPEN-DOC 30155

    LOURENCO, LARISSA R.; BORGES, ROGER; CARASTAN, DANILO J.; MATHOR, MONICA B. ; MARCHI, JULIANA. Chitosan hydrogel containing bioactive glass aiming at 3D printing for tissue engineering. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 349-349.

    Abstract: 3D printing is a rising processing technique in tissue engineering due to high reproducibility and the possibility of complex or even patient-specific models. Chitosan is a promising biomaterial for both 3D printing and tissue engineering, because of its biocompatibility, rheological properties, biodegradability, and cost-effectiveness. Bioactive glasses can help the regeneration of different biological tissues and act as reinforcement for chitosan matrix. In this work, chitosan hydrogels were produced with different concentrations of 58S bioactive glass (0.5 up to 5%wt). For the rheological characterization, frequency, and recovery experiments were carried out. Printability and shape fidelity were evaluated during the 3D printing process. Indirect cytotoxicity assay using Balb/c 3T3 cells was performed to evaluate the biological properties of the scaffolds. The presence of the glass maintained the viscosity properties and increased the recovery percentage. All materials formed filaments and allowed printing with suitable form maintenance. Biological experiments showed high cell viability for all 3D scaffolds, even though a reduction was observed for higher glass concentrations. The results indicate that the studied materials are printable and potentially recommended for tissue engineering applications.

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  • IPEN-DOC 26016

    CARMO, L.S. do ; WATANABE, S. ; SILVA, R.J.; CHUBACI, J.F.D.. Dating aeolian sediments using ESR Ti-Li center in quartz, TL and OSL-SAR: Dama Branca, study. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 23-23.

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  • IPEN-DOC 26027

    GOMES, MONISE B. ; CORTEZ, BRUNA ; OLIVEIRA, LETICIA M. de ; CARMO, LUCAS S. do ; CHUBACI, JOSE F.D.; ROCCA, RENE R.; WATANABE, SHIGUEO. Dating of shells from Pântano da Malhada, Rio de Janeiro. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 81-81.

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  • IPEN-DOC 26028

    CORTEZ, BRUNA ; CHUBACI, JOSE F.D.; GOMES, MONISE B. ; OLIVEIRA, LETICIA M. ; SATIRO, LUCAS C. ; ROCCA, RENE R.; ARIZACA, EDY E.C.; WATANABE, SHIGUEO. Dating sediments from a terrace found in Iguape - Icapara in southeast coast in the state of São Paulo, Brazil. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 85-85.

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  • IPEN-DOC 25512

    GOMES, A.A. ; BUSTILLOS, J.O.W.V. ; VIANNA JUNIOR, A.S.; LANDULFO, E. ; ROSSI, W. de . Development of a microfluidic circuit "microreactor" to atmospheric analyses. In: WORKSHOP LIDAR MEASUREMENTS IN LATIN AMERICA, 10th, November 19-23, 2018, Medellín, Colombia. Abstract... 2018.

    Palavras-Chave: air pollution; atmospheric chemistry; troposphere; ozone; temperature control; measuring instruments; microstructure

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  • IPEN-DOC 29201

    TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; ROSERO, WILMMER A.A. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; NOGUEIRA, THUANY C. ; ANGELOCCI, LUCAS V. ; ROSTELATO, MARIA E.C.M. . Development of a new material to encapsulate phosphorus-32 for use in brachytherapy. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The term cancer refers to a set of malignant diseases that have in common the disordered growth of mutated cells, which can invade adjacent tissues or distant organs[1]. In 2020, cancer of the central nervous system (CNS) represented 1.6% of all new malignant tumor cases in the world, and about 2.5% of all new cancer deaths[2]. A promising radioactive source for use in intracavitary brachytherapy is phosphorus-32. This source has been prominent as a minimally invasive treatment for craniopharyngiomas and in the treatment of metastatic bone diseases in general[3]. To encapsulate phosphorus-32 and make it a viable radioactive source for use in medicine, some methods have emerged. In this work, we are developing a fabric soaked in industrial latex for this purpose, as this source comes in the form of orthophosphoric acid in aqueous solution and as industrial latex is soluble in water. Tests carried out so far show that the material supports orthophosphoric acid while is still malleable, which is essential for treating spinal cancer.

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  • IPEN-DOC 30158

    ROSERO, WILMMER A.A. ; BARBEZAN, ANGELICA B. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Development of radioactive nanoparticles functionalized with gum arabic to be used in nanobrachytherapy. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 553-553.

    Abstract: The development of new materials emerges as an alternative to the treatment of cancer, from the combination of nanotechnology and brachytherapy a new area of research was born, Nanobrachytherapy, which through the properties of nanometric materials can achieve better results in the fight against cancer. The objective of this work is classified as radiotherapy, which consists of the use of ionizing radiation to destroy or inhibit the growth of abnormal cells that form a tumor. [1] The ability to integrate NPsAu into biological systems is due to the nanometric dimensions of NPsAu probes which facilitate their incorporation into biological systems, as well as their bioconjugation and non-cytotoxic potential. [2] Taking into account the previous objective, gold was selected as the base element for obtaining nanometric systems, which due to its chemical richness and especially due to the intrinsic properties of one of its radioisotopes, which would allow us in theory to meet the stated objective. . Initially, it was based on the knowledge of the literature, and non-radioactive nanometric systems were obtained, and after a series of stability, characterization and application tests, the radioactive nanometric systems were obtained. Working with radioactive systems posed a great challenge, and up to now it presents us with situations to solve, but we have managed to create a methodology for obtaining, characterizing and applying radioactive gold nanoparticles, and also obtaining positive results from their application.

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  • IPEN-DOC 25604

    LIMA, CASSIO A. ; CORREA, LUCIANA; BYRNE, HUGH J.; ZEZELL, DENISE M. . Diagnosis of advanced skin cancer using Infrared spectral histopathology. In: LATIN AMERICA OPTICS AND PHOTONICS CONFERENCE, November 12-15, 2018, Lima, Peru. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: In this study, we investigated the feasibility of Infrared Spectral Histopathology to diagnose invasive squamous cell carcinoma using hematoxylin and eosin stained tissue placed on conventional glass slides, as used in the pathologist workflow.

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  • IPEN-DOC 24936

    LIMA, CASSIO ; ZEZELL, DENISE . Discrimination of healthy skin and cutaneous malignant lesions using FTIR spectra and their second derivatives: a comparative study. In: CLINICAL AND TRANSLATIONAL BIOPHOTONICS, April 3-6, 2018, Hollywood, Florida, United States. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: PC-LDA statistical method was used to differentiate cutaneous tumor tissue from healthy skin. Discrimination accuracy obtained by raw FTIR spectra was 95% and by second derivatives 92%, besides identifying secondary structure of proteins and collagen.

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  • IPEN-DOC 26968

    MATOS, B.R. ; SANTIAGO, E.I. ; TOSCO, B.; REY, J.F.Q.; SILVA, J.S. da ; SCHADE, U.; PUSKAR, L.; AZIZ, E.F.; FONSECA, F.C. . Efeito da relaxação do polímero na cristalinidade, fase iônica e formação de grupos sulfônicos anidridos no Nafion / Effect of the polymer relaxation on the crystallinity, ionic phase and sulfonic anhydrides formation of Nafion. In: SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 21., 17-21 de abril, 2017, Natal, RN. Resumo... Campinas, SP: Galoá, 2017.

    Abstract: A relação entre as propriedades estruturais e elétricas de amostras de Nafion preparadas sob tratamento térmico em diferentes temperaturas (220 > T > 100 °C) foi investigada por espectroscopia no infravermelho (FTIR), espalhamento de raios-X em baixo ângulo (SAXS), calorimetria diferencial exploratória (DSC), análise dinâmico-mecânica (DMA) e espectroscopia de impedância (IS). Os resultados combinados de FTIR, SAXS, DSC, DMA revelaram que o tratamento térmico em baixas umidades relativas altera a morfologia do Nafion irreversivelmente devido a três características principais: i) o rearranjo das ligações de hidrogênio; ii) o reordenamento da fase cristalina; e iii) a formação de grupos sulfônicos anidridos. No entanto, a formação dos grupos anidridos é revertida pela reacidificação da membrana em soluções ácidas. O aspecto mais importante da dinâmica dos três processos descritos é que tais alterações são aceleradas acima de uma temperatura crítica: a temperatura de término da transição α do Nafion (Tendα ~ 160 °C). A transição α é atribuída ao enfraquecimento das interações eletrostáticas existentes entre os grupos sulfônicos do Nafion, que permitem a movimentação de longo alcance das cadeias poliméricas [1]. Este resultado indica que a maior dinâmica das cadeias do polímero em T > Tendα é o principal fator envolvido na modificação irreversível da morfologia do Nafion. As alterações da estrutura das ligações de hidrogênio afetaram negativamente as propriedades elétricas do Nafion. O aumento da temperatura de tratamento térmico reduz a condutividade protônica e aumenta a energia de ativação do transporte de cargas no Nafion. Tais resultados são relevantes para a preparação de conjuntos eletrodos-membrana (MEA) e para a operação de células a combustível de eletrólito polimérico (PEFC) em altas temperaturas [1].

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  • IPEN-DOC 28597

    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. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 377-377.

    Abstract: 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. The objective of this work was to demonstrate the three-dimensional culture of fibroblast cells aggregated to nanoparticles for inoculation the T. gondii. 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 of O2 at pH 12. This solution was 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. Tachyzoites were found inside 3T3 cells, assuring that the spheroid can be a suitable culture substrate to T. gondii in vitro propagation. A three-dimensional methodology 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).

    Palavras-Chave: protozoa; nanoparticles; fibroblasts; cell proliferation; in vitro

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  • IPEN-DOC 25611

    DIAS, DERLY A. ; PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; SUGAHARA, VANESSA M.L. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. ; MATHOR, MONICA B. . Effects of gamma irradiation on bovine bone microhardness and molecular structure. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: The skeletal systems is a complex mixed compounds, organic and inorganic, that should present a mechanical resistance to perform functions as protection of the vital organs and load distribution. Gamma radiation is an ionizing radiation that comes from radioative sources or X-ray generator and it is commonly used in health establishments such as radio diagnostic exams, radiotherapy and sterilization of allograft. The characterization of the irradiated bone tissue can be an important tool in the study of the components that are aÆected and how much each dose of ionizing radiation can alter its mechanical properties. This information will be very important in in vitro and ex vivo studies where sterilization of the bone material is necessary and may still be useful in understanding the eÆects on the bone tissue of patients undergoing short-term radiotherapy. For this, 110 samples of bovine femur diaphysis were randomized into 11 groups: G1- untreated (control); G2 to G11 were submitted to gamma irradiation (60Co Gammacel). Samples were polished before irradiation and submitted to a Knoop Microhardness Test to determine the hardness of bovine bone and Fourier transform Infrared spectroscopy (FTIR). Spectra were collected in the midinfrared range in Attenuated Total Reflectance (ATR) sampling mode associated whit PCA multivariate technique to evaluate the molecular changes in bone matrix. The microhardness analysis did not present a significant statistical diÆerence between the irradiated and control groups, showing that ionizing radiation did not aÆect the mechanical structure of the samples, on a micro scale. The results of FTIR with the PCA technique were eÆective in separating all groups, especially those irradiated with doses of 0.002 kGy, 10 kGy and 35 kGy. We conclude that ATR-FTIR spectroscopy associated with PCA is a good method to evaluate the biochemical changes promoted by ionizing radiation in bone matrix. It was observed that hardness was not altered by gamma irradiation and FTIR spectroscopy associated with PCA is a good method to analyze the changes in bone tissue submitted to ionizing radiation.

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  • IPEN-DOC 30151

    OLIVEIRA, RAPHAEL A.M.P. de; TRINDADE, FABIANE J.; FLORIO, DANIEL Z. de; FONSECA, FABIO C. ; ESPOSITO, VINCENZO; FERLAUTO, ANDRE S.. Effects of La content in ceria-lanthana thin films prepared by pulsed laser deposition. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 810-810.

    Abstract: Solid oxide electrochemical reactors are a promising alternative for challenging chemical reactions, such as oxidative coupling of methane (OCM)[1], which convert methane to C2+products. Cerium oxide is a commonly studied oxide membrane material for its high ionic conductivity in the temperature range ideal for conversion reactions (600-900°C), particularly when doped with rare earth cations like Gd, Sm, or La. Recent studies have shown La2Ce2O7as a promising OCM catalyst[2]. This study investigates the structural properties of LaxCe(1-x)O2(1-x/2)thin films, prepared using pulsed laser deposition, with varying stoichiometry. XRD results indicate textured film growth with preferential [100] orientation of cubic crystalline fluorite for low La content (x≤0.5), while x>0.5 had a random orientation. La doping expanded the fluorite structure, increasing lattice parameters from 5.42 Å for x=0 to 5.69 Å for x=0.7. UV-Raman spectroscopy showed that La content x=10 caused a more pronounced balance between Ce4+and Ce3+than pure ceria samples. Impedance revealed a direct relationship between La content and resistance, indicating lower resistance with lower La content. These findings could lead to using Ce-La oxides thin films as catalysts for OCM in electrochemical reactors based on ceria.

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  • IPEN-DOC 24831

    GALDINO, GABRIEL S. ; FERREIRA SOBRINHO, LUIZA ; CRUZ, PEDRO V.D. ; CASINI, JULIO C.S.; SAKATA, SOLANGE K. ; FARIA JUNIOR, RUBENS N. . Electron beam irradiation of reduced graphene oxide-palladium nanocomposite for electrochemical supercapacitor. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Recent work has shown that palladium nanoparticle–graphene composite can be an efficient electrode material in energy storage applications in supercapacitors. These Pd-based supercapacitors showed remarkable properties with a maximum specific capacitance of 637 F g -1 and also exhibited excellent cycle life with 91.4% of the initial specific capacitance retained after 10000 cycles. Palladium nanoparticle decorated graphene composite was synthesized via a chemical approach in a single step by the simultaneous reduction of graphene oxide and palladium chloride from the aqueous phase using ascorbic acid as reducing agent. In the present work, electron beam irradiation has been investigated as an attempt to produce graphene-palladium nanocomposites. Graphite oxide was prepared using a modified Hummers’ method and dispersed in ethanol, exfoliated using ultrasonication to produce Graphene Oxide (GO) and dried for further analysis and processing. This material was thermic reduced in high vacuum (10 -6 mbar) at various temperatures (200-600 o C) and mixed in a solution with palladium. The samples were placed in a 50 ml beaker with Pd(NO 2 ) 2 2H 2 O and were irradiated with 300kGy , dose rate 1,6 kGy s -1 . Irradiation was carried out in an electron accelerator Dynamitron de 37,5 kW (E = 1,5 MeV, 25 mA) (Radiation Dynamics Inc.), The resulting irradiated material was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). These investigations showed that a palladium graphene mixture for supercapacitors applications is formed by electron beam irradiation.

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  • IPEN-DOC 29595

    SAULA, MATHEUS S.N.; FELINTO, MARIA C.F.C. ; NUNES, LUIZ A.O.; MALTA, OSCAR L.; BRITO, HERMI F.. Europium activator ion acting as an efficient luminescent probe to identify local symmetry in Li2ZnSn3O8:Eu3+ materials prepared by the MASS method. In: SILVA, FERNANDO de C. da (Org.) REUNIAO ANUAL DA SBQ, 45., 31 de maio - 3 de junho, 2022, Maceió, AL. Resumo... São Carlos, SP: Aptor Software, 2022. p. 390-390.

    Abstract: Luminescent materials doped with rare earth ions (RE) have been intensely applied in several areas in the new photonic technologies, such as emergency lights, radiation detectors, biological markers, and anti-counterfeiting products. Stannate-based host matrices have attracted significant attention, as they are relatively inexpensive and have a favorable bandgap to allow the persistence luminescence phenomenon. In this work, Li2ZnSn3O8:Eu3+ was synthesized by the microwave-assisted solid-state method (MASS) using a domestic microwave oven after gridding Li2CO3, ZnO, SnO2, Eu2O3 precursor oxides. Therefore, the as-prepared precursors were heated in a static air atmosphere at a preset configuration of 900W for 20 min. The material was characterized by powder X-ray diffraction (PXRD), scan electron microscopy (SEM), and diffused reflectance spectroscopy. The PXRD patterns indicate the formation of the desired Li2ZnSn3O8matrix phase when doped with different concentrations of the Eu3+ ion, showing a high crystallinity. The photoluminescence properties were determined based on the emission spectra of the Li2ZnSn3O8:mol%Eu3+ materials (Fig 1), showing intense yellowish-orange and reddish-orange emission colors under UV excitation at 282 and 336 nm, respectively. Moreover, both spectra show narrow emission bands characteristic of 5D0 →7F0-4 Eu3+ transitions. Sinceeuropium ions are powerful spectroscopic probes for the symmetry of the first coordination sphere of these ions in a lattice, and the spectral profiles change with the incident radiation wavelengths, which demonstrates the presence of more than one site of symmetry around the chemical environment of the Eu3+ion.Finally, it is noteworthy that these luminescent materials can be selectively excited in the UV range, leading to more than one specific emission spectral profile, which can be applied as efficient luminescent probes for anti-counterfeiting products.

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  • IPEN-DOC 29196

    PATRICIO, NICOLE B. ; CARDOSO, JULIANO C. ; LANFREDI, ALEXANDRE J. de C.; ESCOTE, MARCIA T.; SANTIAGO, ELISABETE I. . Evaluation of bifunctional CeO2/ZrO2 catalysts in methane electrooxidation. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Methane (CH4) is the main component of natural gas (70 to 90%), the fossil fuel, whose consumption has grown the most in the world. The International Energy Outlook 2019 projects that global consumption of natural gas will increase by 40% from 2018 to 2050, reaching 200 quadrillion btu [1]. Electro-oxidation of this compound can occur at low temperatures via direct method and the increase in the conversion rate to methanol can be achieved with the development of new efficient catalysts. In this work, the synthesis of CeO2/ZrO2-based bifunctional electrocatalysts was evaluated using the hydrothermal process assisted by microwave, varying the proportions in the ratios of 1:2, 2:1 and 1:6 Ce/Zr, respectively. Such mixtures are used as starting precursors to form mixed metal oxides and solid solutions followed of heat treatment at 200ºC for 30 minutes for phase formation, called mixed oxides (CexZryO2) and solid solutions (CeO2/ZrO2). The electro-oxidation of methane under potentials of 1.1V and 1.6V vs. Ag/AgCl led to the majority formation of methanol, ethanol, and acetone as the main products of this conversion in sodium carbonate medium as an electrolyte. However, these conversions are more pronounced from the variation of Ce/Zr ratios to produce both alcohols with 2.4% and 4.2% efficiency for CeO2/ZrO2(1:1), respectively, while CeO2/ZrO2(1:2) generates only methanol with a higher efficiency of 6.9%. Thus, under optimized conditions, it was possible to observe that ceria and zirconia oxides can efficiently promote the conversion of methane to other commercially valuable products using suitable oxidation potentials and, therefore, be a promising alternative for this reaction.

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  • IPEN-DOC 29574

    DEL-VALLE, MATHEUS ; CARVALHO, MARCELO; SANTOS, MOISES ; PINTO, NATHALI; JATENE, FABIO; POMERANTZEFF, PABLO; BRANDAO, CARLOS; ZEZELL, DENISE . Evaluation of calcified mitral valves after Er,Cr:YSGG irradiation using Optical Coherence Tomography. In: INTERNATIONAL CONFERENCE ON LASER APPLICATIONS IN LIFE SCIENCES, 16th, April 1-2, 2022, Nancy, France. Abstract... Nancy, France: PROGEPI, 2022. p. 152-152.

    Abstract: Mitral valve is responsible to control the left atrium-ventricle blood flux. Mitral stenosis is a disease that occurs in consequence of calcification and fibrosis on the cuspids of the valve. Diagnosis can be performed using echocardiography.Many treatments are possible, and one of them is commissurotomy (surgical approach).High intensity laser irradiation may be a new strategy for this surgical technique[1], and the optical coherence tomography (OCT) may contribute to the valve evaluation[2], asit provides higherspatialresolutionin exchange of lower penetrationthan ultrasonography. In this way, the aim of this study is to evaluate laser irradiation effectsincalcified mitral valvesusing OCTand digital processing.To that, it was conducted an ex-vivostudywith four human mitral valvessamples,obtained from valve replacement surgeries in the Heart Institute.The samples were splitin four groups: scalpel cut, laser cut, scalpel debridement and laser debridement.Cutting and debridement procedures were performed in calcified regions of the valves, usinga disposable scalpelbladeand anEr,Cr:YSGG laser(Waterlase; Biolase Inc., CA, USA), emitting at 2780 nm. The laser parameters were set at power = 1.6W, frequency = 20 Hz, energy density = 28.3J/cm2,pulse duration = 700 μs, 15% of water and 15% of air.The imaging was performed using a spectraldomain OCT system(Callisto110C1;ThorLabs Inc., NJ, USA).It was acquired10 B-scans per sample, 5 inprocedures regions and 5 in sound regions. The Optical Attenuation Coefficient (OAC) was calculated by comparing a beer-lambert like equation to exponential fittings of the A-scans[3].The distribution and normality of variances were tested using Shapiro-Wilk test,and statistical comparison was performed using one-way ANOVA and Tukey’s post hoc. All tests considered a level of significance of 5%.The FigureAshows a representative B-scan of a visibly calcified region, where a pattern of higher intensities can be observed.Thispattern is related tomorphological and optical changes, mainly a refractive index change, due to calcium presence in the valve tissue.This B-scan was acquired only to understand the calcified tissue aspect, as the procedures regions does notpresent visibly largecalcium stones.The Figure Bshowsthe statisticalanalysis, where the sound OAC values, as a mean of all sound regions, presented a significant statistical difference in comparison to scalpel groups, while no difference waspresentedin relation to laser groups. Higher OAC values are related to anaugmentation of the light backscatteringdue to calcium refractive index, leading to a change of lightpropagation in tissue-calcium interfaces.This finding indicates thatthe laser procedures promoted a better removal of calcified tissue than the scalpelmethods, which can be related to tissue-ablation interaction.Furthermore, the statistical difference between scalpel cut group and both laser groups suggests that the scalpel needs more wear interaction with the tissue, such as in the debridement procedure, being unable to significatively remove the calcification in a single cut.This study points the Er,Cr:YSGG and the OCT as potential techniques for the calcified tissue removal and evaluation,respectively, duringmitral valvessurgeries, although further studieswith higher sample numbermust be performed.

    Palavras-Chave: cardiovascular system; valves; cardiovascular diseases; fibrosis; tomography; coherent radiation

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  • IPEN-DOC 24825

    BATISTA, JORGE G.S. ; BARROS, JANAINA A.G. ; VARCA, GUSTAVO H.C. ; ROGERO, SIZUE O. ; CAVALCANTE, ADRIANA K. ; MAZIERO, JOANA S. ; ROGERO, JOSE R. ; LUGAO, ADEMAR B. . Evaluation of the in vitro and in vivo toxicity of gold nanoparticles synthesized by green nanotechnology. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Researchers and laboratories around the world have studied gold nanoparticles. In medicine, several studies demonstrate the applicability of gold nanoparticles (AuNPs) in the treatment and diagnosis of cancer. Green nanotechnology uses phytochemical agents to synthesize and stabilize nanoparticles. The phytochemical epigallocatechin-gallate (EGCG) reduces and stabilize gold nanoparticles by functionalizing the surface of the molecule. Such chemical groups allow binding to overexpressed receptors on some types of tumors as demonstrated in studies performed with PC3 prostate cancer cells. With the advancement of nanotechnology, a large number of nanoparticles are produced on a daily basis. However apart from their possible applications it is necessary to evaluate the environmental impact of these molecules as well as find ways for proper disposal. The embryonic zebrafish (Danio rerio) trial has recently emerged as an interesting method for evaluating in vivo nanotoxicity providing a more complex system analysis than in typical cell cultures and less expensive if compared to large-scale biocompatibility studies performed in rats and mice. The objective of this study was to evaluate the in vitro and in vivo toxicity of EGCG-AuNPs by means of the cytotoxicity by neutral red uptake methodology according to the International Standard Organization [ISO 10993-5, 2009] and in vivo test based on the OECD guideline on Fish Embryo Toxicity Test (FET) (OECD, 2013). The spectrophotometric band at 535 nm observed is characteristic of the formation of AuNPs. Nanoparticles synthesized with EGCG presented a size of 32 ± 4 nm as determined by transmission electron microscopy and the hydrodynamic diameter of these particles was about 60 ± 18 nm obtained by dynamic light scattering. The EGCG-AuNPs showed no cytotoxicity up to 4.2 μg.L-1. In the FET test regarding the acute ecotoxicity assay the LC50/96 hours revealed no toxicity at concentrations up to 1.8 mM.

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  • IPEN-DOC 29319

    WETTER, NIKLAUS ; FREITAS, ANDERSON Z. ; BERECZKI, ALLAN ; PASCOAL, DIEGO R.C. ; DIPOLD, JESSICA ; PARRA, DUCLERC ; ROSSI, WAGNER ; CABRAL, FERNANDA V. ; RIBEIRO, MARTHA S. . From micro to nano Raman: new developments in the detection of micro and nanoplastics of marine origin from the Amazon basin to Santos. In: ENCONTRO BRASILEIRO DE ESPECTROSCOPIA RAMAN, 7., 5-8 de dezembro, 2022, São Pedro, SP. Resumo... 2022.

    Abstract: The environmental accumulation of nanoplastics formed by material of anthropic origin has raised doubts about their safety, especially to the human body. While microplastics are accidentally consumed, nanoplastics (NPs) are even more concerning as they are much more likely to be absorbed by human body cells. It is known that plastics smaller than 200 nm can penetrate cell membranes and cross the blood-brain barrier. Studies have shown that polystyrene (PS) NPs from the environment carry a high load of toxins capable of compromising human brain cells. Very little is still known about what effects, cytotoxic or not, these plastics have on different organs. Understanding the property-function relationship of nanoparticles in various fields of application involves determining their physicochemical properties, which is still a formidable challenge to date. Our project focuses on the development of a methodology for the detection of micro- and NPs using micro-Raman, TERS (Tip Enhanced Raman Spectroscopy), collinear Raman and AFM, nuclear techniques, as well as a methodology for in vitro evaluation of the toxic effects of these materials through biochemical assays of cytotoxicity and genotoxicity. The project contemplates the determination of the adsorption capacity of metallic ions by NPs and the absorption of micro- and nanoplastics in cell cultures with radioactive tracers, the determination of microplastics in tissues from necropsies of marine animals and gamma spectroscopy of the cellular incorporation of NPs labeled with radioactive isotopes. In figure 1 we show examples of (a) the detection of microplastics from the Santos basin and comparison to Raman reference database (KnowItAll®), (b) detection of NPs in mouse fibroblast cells and (c) detection of very small particles (50 nm) which can be achieved by co-localized techniques of AFM + Raman using special, narrow (50 m), femtosecond laser written gratings on quartz.

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A pesquisa no RD utiliza os recursos de busca da maioria das bases de dados. No entanto algumas dicas podem auxiliar para obter um resultado mais pertinente.

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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.

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.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

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.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

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.