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Navegação Eventos - Resumos por Agências de fomento "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)"

Navegação Eventos - Resumos por Agências de fomento "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)"

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  • IPEN-DOC 26006

    PEREIRA, DAISA L. ; CASTRO, PEDRO A.A. ; GOMES, GABRIELA V. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. ; RIBEIRO, HENRIQUE B.; MATOS, CHRISTIANO J.S.; ANA, PATRICIA A.. Heat-induced depth of Nd:YAG laser irradiation in biological hard tissues. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Confocal Raman spectroscopy is a non-destructive and non-invasive technique which provides surface Raman spectra and depth images of biological structures contactless with the sample, with no use of ionizing radiation to penetrate in the sample under analysis. These characteristics allow its experimental use without any side e®ects to the sample. The depth images are obtained by Raman microscopy and are related to the characteristics of the tissues. This study aims to characterize irradiated hard tissues and correlate the depth reached by the heat of the laser irradiation with the obtained images. For this, thirty 8 mm2 blocks of bovine enamel and bovine root dentin, were randomized into 6 groups: G1- enamel untreated; G2- enamel irradiated with Nd:YAG micropulsed laser (1064 nm, 10 Hz- Lares Research R°) using a coal paste as photoabsorber; G3- enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G4-G6 (bovine root dentin in the same conditions of treatment of G1-G3). The measurements were performed in three di®erent depth regions of the cubic shaped samples: region A- left corner above of the sample, region B- middle of the sample and Region C- right corner below of the sample. The area under the phosphate, carbonate, amide I, II, and III bands were calculated. The Raman spectra of the Nd:YAG irradiated samples detected a reduction in all the organic components of the enamel after laser irradiation. Previous studies of our group demonstrated that di®erences in carbonate substitution in the apatite lattice are related to the apatite instability and demineralization susceptibility. Considering that carbonate free apatite is less susceptible to acid attack, the results of this study suggest that Nd:YAG lased enamel can be more resistant to caries, in a direct correlation to the thickness of the treated area. It was found that for micropulsed Nd:YAG laser, the heat induced depth was 10 § 2 ¹m and for nanopulsed laser the heat induced depth was 8 § 3 ¹m. So, it is possible to correlate the heat penetration depth of the laser irradiation with the images obtained by the confocal Raman.

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  • IPEN-DOC 23456

    AMARAL, M.M. ; TEIXEIRA, L.R.C. ; CARVALHO, M.T.; GOMES, A.S.L.; ZEZELL, D.M. . Hemangioma vascular lesion characterization by optical coherence tomography. In: ENCONTRO DE FISICA, 03-07 de setembro, 2016, Natal, RN. Abstract... São Paulo: Sociedade Brasileira de Física, 2016.

    Abstract: Hemangioma vascular lesions are common childhood tumors appearing mainly in the neck and head. It affects 10% of children worldwide [1]. In most cases the lesions does not bring consequences for the patient's health, although some patient can develop complications caused by tissue deformities. In extreme cases, it could be a life risk. The early diagnosis of the lesion could lead to an early treatment and a reduction on its aesthetic and psychological consequences. In this work, we evaluate the use of the Optical Coherence Tomography to differentiate between hemangioma vascular lesions from normal skin. Using a swept source OCT (9 m and 18 m axial and lateral resolution) 541 images of hemangioma lesion and 50 image of normal skin on the hand region was acquired. IMIP Ethics Committee approved this study (protocol no. 728.993). In order to characterize the normal skin and the hemangioma vascular lesion it was implemented an automated analysis using Matlab ©. Two approaches was implemented, a morphological analysis [2] to evaluate the epidermis thickness and an attenuation coefficient analysis [3] to evaluate the optical feature of the tissue. It was possible to evaluate the depth distribution of epidermis for booth normal skin and hemangioma lesion. Normal skin presented a thicker epidermis layer and a broader distribution, while hemangioma lesion presented a narrower epidermis layer and uniform distribution. The attenuation coefficient of hemangioma lesion presented 9.2% higher values than normal skin. Booth approaches proved to be valid for hemangioma diagnosis and could be complementary to each other and the combination of these approaches will be discussed in this work.

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  • IPEN-DOC 23273

    BONTURIM, E. ; REIS, R. dos; MERIZIO, L.G.; RODRIGUES, L.C.V.; BRITO, H.F.; FELINTO, M.C.F.C. . Investigation of rare earth distribution in Sr2MgSi2O7:Eu2+,Dy3+ nanophosphors prepared by wet-chemical routes. In: INTERNATIONAL CONFERENCE ON LUMINESCENCE, 18th, August 27 - September 1, 2017, João Pessoa, PB. Abstract... 2017.

    Abstract: Luminescent materials have been developed through ne chemistry methods that help to achieve a better control of parameters such as morphology, particle size, atomic homogeneity and high purity single phase in low temperature synthesis.[1, 2] In this work, the material Sr1:98MgSi2O7 nanoparticles doped with 0.01 mol of Eu2+ and codoped with 0.01 mol of Dy3+ was prepared via Pechini and Condensation methods. Post-annealing by microwave assisted method using granular coal as the susceptor/reducing agent [3] was applied on both materials and their luminescent properties were compared. The structural position of Eu2+ used as the activator ions determines photoluminescence properties. The luminescence spectra of Sr2MgSi2O7:Rn+ nanomaterial (R: Eu2+, Dy3+) shows a high emission broad band assigned to the intercon gurational transition 4f65d1 ! 4f7 centered around 460 nm, which is overlapped with a low emission lines attributed to the 4F9=2 ! 6H13=2 transition of Dy3+ ion (Fig. 1b). Elemental mappings obtained by Energy Dispersive X-Ray (EDX) presents dopants more likely to be found at the edge, indicating a possible segregation of rare earths to the grain boundaries during the synthesis (Fig. 1c). The persistent luminescence phenomenon emitting in a blue region was observed for both nanomaterials.

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  • IPEN-DOC 28558

    PELOSI, ANDRE G.; SANTOS, SABRINA N.C. dos; DIPOLD, JESSICA ; ANDRADE, MARCELO B. de; HERNANDES, ANTONIO C.; ALMEIDA, JULIANA M.P. de; MENDONCA, CLEBER R.. Investigation of the influence of transition metal ions in niobium-borotellurite glasses through vibrational and nonlinear optical spectroscopy. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 176-176.

    Abstract: Tellurite glasses are know as good candidates to photonic devices’ production because they exhibit third-order nonlinear optical susceptibilities larger than conventional silicate and borate glasses. In addition, for glass materials such nonlinearity can be increased by adding transition or heavy metal ions. In this direction, this work analyzed the influence of Ta5+ and Zr2+ on the physical, structures, and nonlinear optical properties of niobium-borotellurite (TBN) glasses. The samples were synthesized by the melt-quench technique using a melting temperature of around 1000 ºC. DSC measurements were performed to obtain the glass transition temperature. The densities were determined by the Archimedes method. To analyze the local structure of the samples FTIR and Raman spectroscopies were used . The spectrum of nonlinear refractive index (n2) for the TBN glass doped with Ta5+ and Zr2+ ions was measured using the tunable femtosecond Z-scan technique [1]. Such results were compared with the BGO model, which involves empirical relations between the linear and nonlinear refractive index. The addition of metal transition ions did not lead to meaningful changes in the glass transition temperatures (Tg). The formation of non-bridging oxygen and BO3 units was observed from the structural analysis. The n2 value determined indicates that the nonlinear optical responses are associated with the glass matrix. The structural changes caused by the addition of Ta5+ and Zr2+ demonstrated a decrease followed by an increase in the value of the molar electronic polarization of the samples, respectively.

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  • IPEN-DOC 30104

    FABRETTI, L.T.; SILVA, D.F.T. ; RAELE, M.P. ; KATO, I.T.. Light-tissue interaction of laser with neonatal rat brains. In: WORKSHOP DE ENGENHARIA BIOMEDICA, 1., 8-9 de março, 2023, Online. Resumo expandido... São Bernardo do Campo, SP: Universidade Federal do ABC, 2023. p. 84-85.

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  • IPEN-DOC 28975

    ZEZELL, DENISE M. . Machine learning methods for micro-FTIR imaging classification of tumors and more. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 45., 10-14 de abril, 2022, São Paulo, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: Fourier transform infrared micro-spectroscopy imaging (µ-FTIR) has emerged as one of the important tools for studying and characterizing biological materials. It is a label-free technique, relatively simple, reproducible, non-destructive to the tissue and provides accurate results. The vast amount of data and fundamental information obtained from hyperspectral images may not be readily evident. Classical statistics, through its models (parametric and non-parametric) is not able to support the increasing volume of generated data and its high dimensionality. The multivariate analysis of data presents many advantages to be explored, capable of extracting information from the infrared spectra, which go beyond the one-dimensional space, revealing characteristics or properties in the data collected from the samples. The spectral data analysis pipeline, such as the pre-processing steps and the modeling that the Biophotonics Laboratory at Ipen – Cnen, is using in the analysis of biological tissues will be discussed. Results will be presented for body fluids in the disease diagnosis, as well as thyroid, skin and breast tumors, in particular the expression of estrogen and progesterone receptors through tumor biopsies of human cell lines inoculated in mice. µ-FTIR images were collected from histological sections, and six machine learning models were applied and evaluated. The Xtreme gradient boost and Linear Discriminant Analysis showed the best accuracy results, indicating that they are potential models for breast cancer classification tasks.

    Palavras-Chave: fourier transformation; infrared spectra; animal tissues; neoplasms; tumor cells; diagnostic techniques

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  • IPEN-DOC 30026

    GOMES, ANTONIO A. ; NARIO, ARIAN P. ; LAPOLLI, ANDRE L. ; LANDULFO, EDUARDO ; BERNARDES, EMERSON S. ; ROSSI, WAGNER de . Microfluídica, uma tecnologia aplicada à concentração de 18F para produção de radiofármacos. In: CONGRESSO BRASILEIRO DE MEDICINA NUCLEAR, 37., 21-23 de setembro, 2023, Porto de Galinhas, PE. Resumo... São Paulo, SP: Sociedade Brasileira de Medicina Nuclear - SBMN, 2023.

    Abstract: Introdução. O uso de radiofármacos marcados com 18F para o diagnóstico clínico por imagem PET (tomografia por emissão de pósitrons) de diversas doenças tem aumentado consideravelmente. O maior radiofármaco aplicado a diagnósticos com PET é o [18F]-2-desoxi-2-fluoro-D-glicose (FDG) e a sua preparação requer a utilização de equipamentos especializados (e caros) para proteger o farmacêutico que o prepara. Assim, à medida que a demanda de radiofármacos PET aumentar, colocará uma pressão significativa nas instalações de produção de traçadores PET, a qual necessitará de investimento em novas tecnologias de produção de radiofármacos. Uma tecnologia chave desenvolvida nos últimos tempos tem sido o uso de sistemas microfluídicos. Os dispositivos microfluídicos oferecem muitas vantagens para a síntese de radiofármacos de curta duração (por exemplo, 18F)tais como: reações mais rápidas, transferência de calor eficiente, alta relação superfície – volume e rendimentos mais elevados. Embora os sistemas microfluídicos estudados para radiofármacos existam há quase 20 anos, no Brasil, até onde sabemos, esta tecnologia e estudo é inédita. Objetivos. Apresentar os primeiros resultados no desenvolvimento de um chip microfluídico para uma “microcoluna” destinada ao processo de retenção e eluição de 18F. Metodologia. A microcoluna foi usinada em vidro óptico de borosilicato – BK7 utilizando a técnica de ablação com laser de pulsos ultracurtos. Após a microusinagem, a microcoluna é preenchida com a mesma resina utilizada no cartucho convencional de síntese “Sep-Pak Accell Plus QMA Plus Light” da fabricante Waters™. Ambas são posteriormente submetidas a testes de desempenho comparativos de eficiência na fase de retenção e eluição de 18F. Resultados. Foram realizados 4 testes comparativos para ambas as fases (primeira etapa da síntese de 18F-FDG), com atividades (1,5 ± 0,3 mCi e 248 ± 11 mCi; “n = 2”). Os resultados demostraram que a eficiência da microcoluna é equivalente à da coluna convencional (QMA Plus Light) na fase de retenção (99,3% ± 0,67 vs99,6% ± 0,32). No entanto, na fase de eluição de 18F, houve uma diferença significativa entre ambas (99,93% ±0,18 vs 77,38% ± 15,54), destacando a grande vantagem da microcoluna. Conclusão. A integração do cartucho de troca iônica em um chip, com a técnica de ablação com laser de pulso ultracurto, abre as portas para chips de radiofarmácia menores e mais eficientes para a produção de 18F-FDG e outros compostos. Os resultados experimentais inéditos no Brasil demonstram que as etapas iniciais da produção de doses prontas para humanos (pré-concentração de flúor) podem ser realizadas com uma eficiência superior nos parâmetros de eluição do 18Fem comparação a síntese com cartucho convencional.

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  • IPEN-DOC 26007

    LIMA, CASSIO ; BYRNE, HUGH; CORREA, LUCIANA; ZEZELL, DENISE . Molecular pathology via infrared spectral imaging for skin cancer diagnosis. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a rapid and label-free analytical technique that provide information about the overall biochemical pro¯le of biological samples based on the vibrations of its basic molecular components (carbohydrates, proteins, lipids and nucleic acids) that are infrared active. The potential biomedical applications of FTIR spectroscopy as a tool for cancer diagnosis have been well demonstrated over the last years. However, most studies have focused on evaluate the diagnostic ability of FTIR by comparing healthy tissue to cancers on advanced stage and few studies have centered on evaluating the early stages of cancer. Thus, the present study aims to demonstrate the ability of FTIR spectroscopy to discriminate healthy skin from advanced skin cancer (squamous cell carcinoma) as well as from early stages of malignancy using the information retained by spectral data. Cutaneous neoplastic lesions were chemically-induced on Swiss mice using a well-stablished two-stage carcinogenesis protocol. Healthy tissue was collected from animals non-exposed to chemicals and di®erent disease stages were obtained by varying the exposure time of animals to carcinogenenic factors. Tissue sections were obtained from formalin-¯xed para±n-embedded (FFPE) and placed on calcium °uoride substrates. FTIR hyperspectral images were acquired in transmission mode over mid-infrared spectral region and compared using Principal Components Analysis (PCA) associated to Linear Discriminant Analysis (PC-LDA). Satisfactory data discrimination (accuracy, sensitivity and speci¯city) was achieved by PC-LDA and the variables responsible by classi¯cation were evaluated in order to assess the spectral changes of skin components during the transition of healthy into diseased state. Our ¯ndings demonstrate the potential of FTIR spectroscopy not only for skin cancer diagnosis, but also to evaluate the biochemical events triggered by cancer without requiring laborious and time-consuming procedures or expensive labeled probes as biomarkers.

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  • IPEN-DOC 25597

    AMARAL, M.M.; TEIXEIRA, L.R.C. ; GOMES, A.S.L.; ZEZELL, D.M. . Optical attenuation coefficient measurement of hemangioma vascular lesion in labial mucosa by Optical Coherence Tomography. In: CONGRESSO BRASILEIRO DE ENGENHARIA BIOMEDICA, 26., 21-25 de outubro, 2018, Búzios, RJ. Resumo expandido... Rio de Janeiro: Sociedade Brasileira de Engenharia Biomédica, 2018.

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  • IPEN-DOC 25610

    PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; ZEZELL, DENISE M. ; DEL VALLE, MATHEUS; ANA, PATRICIA A.. Optical coherence tomography provides the optical attenuation coefficient of bovine dentin irradiated by Nd:YAG. 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: Optical Coherence Tomography (OCT) is a non-destructive and non-invasive technique which provides transverse images of biological structures contactless with the sample, with no use of ionizing radiation to penetrate in the sample under analysis. These characteristics allow its clinical use without any side eÆects to the patient. The optical attenuation coe±cient (OAC) is obtained by OCT and is related to the characteristics of the tissues. This study aims to analyze the OAC from the OCT signal in bovine dentin to distinguish sound from demineralized dentin. For this, sixty 8mm2 blocks of bovine root dentin, were randomized into 4 groups: G1- untreated; G2- treated with acidulated phosphate fluoride (APF, [F]=1.23%, pH=3.3 to 3.9); G3- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz- Lares Research R∞) without photoabsorber; G4- irradiated with Nd:YAG laser (1064 nm, 0.6W, 10 Hz- Lares Research R∞) using a coal paste as photoabsorber. All samples were submitted to a 3-day erosive demineralization protocol (Citric acid 1%, pH=3.6, 5 min, 2x/day) under agitation, and remineralization (artificial saliva, pH=7, 120 min) cycling. In this study, it was noticed that the values of optical attenuation coe±cient of all samples decreased after the erosive cycling. This finding indicates that the demineralization promoted by acids, such as the citric acid creates empty spaces in the structure of dentin that increases the number of interfaces and, as a consequence, increases the scattering of light and decreases the values of optical attenuation coe±cients. It is possible to conclude that the optical attenuation coe±cient, calculated from the OCT signal, is able to distinguish sound from demineralized bovine dentin. This quantitative parameter can be used for diagnosis and to monitor the evolution of mineral loss in patients in near future.

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  • IPEN-DOC 26008

    AMARAL, MARCELLO M.; ARAUJO, JEANN C.R.; ANTUNES, ANDREA; MONTE, ADAMO F.G.; CARA, ANA C.B. de ; FREITAS, ANDERSON Z. de ; ZEZELL, DENISE M. . Phantom validation of optical attenuation coefficient estimation model with depth resolution for Optical Coherence Tomography. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Optical Coherence Tomography (OCT) has been used for imaging and analyzes over a broad number of applications.[1-3] Besides its use for morphological analysis [3] the OCT signal has been used to determine the optical attenuation coe±cient of biological samples for classi¯cation and diagnostic proposes. [1,2] The most common model for estimating the optical attenuation coe±cient based on OCT signal relies on the Lambert- Beers law. It usually assumes a constant attenuation coe±cient value over the image range or over a selected range, losing the in-depth resolution on OCT. Previous published work on literature developed a model to esti- mate the attenuation coe±cient with depth resolution [4], however it assumes that the light is totally attenuated within the image depth range failing for membrane like samples. We present a model that, using the tissue sample transmittance as input, remove this limitation and to estimate the depth-resolved optical attenuation coe±cient. This method allows us to obtain an image of tissue optical properties instead of that from intensity contrast, guiding diagnosis and tissues di®erentiation, extending its application from thin to tick samples. The performance of our method was tested with the assistance of a home built single layer and multi-layer phantoms ( 100¹m each layer). These optical phantoms are composed of a substrate polydimethylsiloxane (PDMS), Zinc- Phthalocyanine (ZnPc) dye as chromophores, and TiO2 as scattering agent. The optical attenuation coe±cient ranges from 0:9 to 2:32 mm¡1, measured using an integrating sphere followed by the Inverse Adding Doubling processing technique. We show that the estimated depth-resolved attenuation coe±cient recovers the reference values, with a error deviation of 7 %.

    Palavras-Chave: tomography; phantoms; optical equipment; optical properties; resolution; images; coherence length; coherent radiation

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  • IPEN-DOC 30133

    PINTO, MAYARA S. ; ROSERO, WILMMER A.A. ; ROSTELATO, MARIA E.M.C. ; RIBEIRO, MARTHA S. . Photobiomodulation therapy combined with radioactive gold nanoparticles in breast cancer-bearing mice. In: ANNUAL MEETING OF THE BRAZILIAN BIOPHYSICAL SOCIETY, 47th, October 19-22, 2023, Campinas, SP. Abstract... Campinas, SP: Galoá, 2023.

    Abstract: Breast cancers are responsible for the highest number of worldwide deaths among women requiring new therapeutic strategies to promote better life’s quality and survival rates for patients. Nanobrachytherapy (NB) and photobiomodulation therapy (PBM) emerge in this context as less invasive approaches for breast cancer treatment. NB is a technique that might deliver high doses of ionizing radiation in a shorter time and in a localized way in comparison to conventional radiotherapy and PBM could enhance cell sensitivity when applied before NB. In this work, we aim to investigate the impact of PBM combined with NB involving radioactive gold nanoparticles (AuNPs) in the treatment of breast cancer in a murine model. Murine 4T1 cells were cultivated in RPMI medium and after injected into the lower-left mammary fat pad animals’ breast. When the tumor reached approximately 0.1 cm3, AuNPs (~284 microCi) were inoculated in the mouse breast. Thereafter, the tumor was irradiated with a red LED (660 nm, 40 mW, 150 s, 6 J) in a single application. Animals were monitored for 3 weeks until euthanasia. Our results demonstrated an arrestment in tumor growth for NB group in comparison to Control, PBM and PBM + NB groups. These data suggest that a single PBM session was not able to enhance the NB of breast cancer. The following steps will involve applying NB and PBM in two sessions. The first session will take place on the same day as NB application, and the second one after 6 days, corresponding to two half-lives of 198AuNPs.

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  • IPEN-DOC 30131

    LIMA, GEYSE S. de; SOUZA, SUEDEN O. de; RAPOSO, BRUNO L.; SANTANA, GLEYCIANE S. de; SARMENTO-NETO, JOSE F.; SANTOS, BEATE S.; NEVES, REJANE P.; RIBEIRO, MARTHA S. ; REBOUCAS, JULIO S.; CABRAL FILHO, PAULO E.; FONTES, ADRIANA. Photodynamic inactivation of Candida glabrata boosted by association of silver nanoparticles with cationic ZnTE-2-PyP4+ porphyrin. In: ANNUAL MEETING OF THE BRAZILIAN BIOPHYSICAL SOCIETY, 47th, October 19-22, 2023, Campinas, SP. Abstract... Campinas, SP: Galoá, 2023.

    Abstract: Candida glabrata, a high priority fungal pathogen, presents alarming incidence and resistance potential to available antifungals. In this scenario, photodynamic inactivation (PDI) introduces a promising antifungal approach, especially in resistant cases. PDI occurs when a photosensitizer (PS) is excited by an appropriate light source, leading to production of reactive oxygen species (ROS). Zinc porphyrins (ZnPs) are attractive PSs for their efficient ROS generation and cellular uptake. The plasmonic effect of silver nanoparticles (AgNPs) can be explored to potentiate the action of PSs, such as ZnPs, in PDI. Therefore, this work aimed to study the association of AgNPs with ZnTE-2-PyP4+ (ZnP-ethyl) in PDI against C. glabrata. AgNPs were synthesized and characterized by absorption spectroscopy and electron microscopy. The association AgNP:ZnP-ethyl was evaluated by zeta potential (ζ) analyses as well as absorption and emission spectroscopies. The systems containing AgNP:ZnP-ethyl (at different proportions; v/v) and different ZnP-ethyl concentrations (0.5 – 1.5 µM) were prepared and incubated with a resistant isolate of C. glabrata, followed by illumination with a blue LED. The PDI effect was assessed by quantifying colony forming units. AgNPs presented spherical morphology and extinction maximum at ~410 nm, overlapping with the ZnP-ethyl absorption spectra. Variations in ζ confirmed the association between AgNPs and ZnP-ethyl, corroborated by subtle changes in the ZnP spectroscopic profile. The AgNP:ZnP-ethyl systems promoted complete fungal eradication at 0.6 µM, while at 0.5 µM they promoted yeast reduction of ca. 5.7 log10 (1:4; v/v) and 6.8 log10 (4:1; v/v). Illuminated AgNPs had no antimicrobial effect alone, and individual ZnP-ethyl (1.5 µM) promoted a 2 log10 reduction. These results show the benefit of AgNPs:ZnP-ethyl association to boost PDI efficiency against resistant C. glabrata isolates. This is a promising antifungal approach to treat resistant candidiasis.

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  • IPEN-DOC 28596

    SEPULVEDA, ANDERSON F.; FRANCO, MARGARETH ; YOKAICHIYA, FABIANO; ARAUJO, DANIELE de. POLYana: a new software for rheological study of polymeric colloidal materials. 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. 374-374.

    Abstract: 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. The software development aims to facilitate the analysis of rheology data associated to both temperature- and frequency-dependent analysis, viscosity and curve flow profiles. 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. 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. 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.

    Palavras-Chave: programming; data analysis; rheology; micellar systems; colloids

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  • IPEN-DOC 30157

    TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; NOGUEIRA, THUANY C. ; ROSERO, WILMMER A.A. ; VIEIRA, JOSE M. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Possible molds for a new brachytherapy source for spinal and intracranial cancer. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 461-461.

    Abstract: Central Nervous System (CNS) cancer is the 18th most incident cancer in the world, according to the World Health Organization (WHO), and in 2020, in Brazil, it represented 2.5% of all new cancer deaths [1]. Brachytherapy is a type of radiotherapy that positions the radioactive source close to (or in contact with) the tumor. Thus, the targeted region receives most of the dose, protecting the healthy tissues adjacent to the tumor. A promising radioactive source for use in brachytherapy for the treatment of CNS cancer is phosphorus-32 in a polymeric substrate. This source has been prominent as a minimally invasive treatment for craniopharyngiomas and in the treatment of metastatic bone diseases in general [2]. To produce such a source, it is necessary to search for possible molds that can conform the polymeric material into the desired format. Several tests were carried out to determine the best mold for the radioactive source manufacture. Different materials were tested to observe if the mold material would react with the source's components, silicone rubber mixed with orthophosphoric acid. In order to be considered a possible mold, the mixture should cure; if the cure did not concretize, the mold would be descarted. It was concluded that polystyrene (PS) obtained the best result, due to the ease of unmold after the resin curing process.

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  • IPEN-DOC 29589

    PAPAI, RODRIGO; ALMEIDA, GILMAR A. ; SILVEIRA, JOAO R.F.; SILVA, ANDRE L.N.; SANTOS, CELIA A.L.; NAGASIMA, THIAGO P.; JABES, EDUARDO G.; LANDGRAF, FERNANDO J.; LUZ, MACIEL S.. Proposal of an analytical method for Nd, Pr, Fe and B determination in super-magnet alloys by ICP OES. 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. 132-132.

    Abstract: Present in motors, electric turbines and data storage devices (hard disk), magnets are indispensable in the manufacture of computers, televisions, cell phones, smart watches and several modern electronic devices. The chemical composition of the magnet directly influences its magnetic performance and consequently impacts the performance of the products with which it is associated. In this context, the knowledge of the majority chemical composition of these materials contributes to an efficient quality control in the act of production and helps the producers of the high-technology industry to select the magnets in order to maintain a uniformity of these materials. Although there are several types of magnets, those that use rare earth elements generally have strong magnetic activity, and are often called super-magnets. Among the rare earth elements, the mixture of neodymium and praseodymium (didymium) is widely used in metal alloys together with the elements iron and boron for its performance as a supermagnet. The (Nd,Pr)FeB alloy production consists, in summary, to obtain metallic didymium by electrolytic reduction of didymium oxide (mixture of neodymium and praseodymium oxides) followed by iron and boron elements incorporation. The chemical composition control is important to avoid undesirable phases, such alpha-iron, and to control the microstructure formation during the alloy manufacturing step. The chemical composition range must be optimized such that minimizes the use of rare earth elements (Nd and Pr). In this context, this work evaluated the best instrumental conditions for the determination of alloy elements by ICP OES. Interference studies were carried out and the developed method was validated through interlaboratory tests and addition and recovery tests.

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  • IPEN-DOC 29575

    CASTRO, PEDRO ; PEREIRA, DAISA ; ANA, PATRICIA; MATOS, CHRISTIANO; ZEZELL, DENISE . Q-switched Nd:YAG laser on dental enamel with photoabsorber: a confocal Raman pilot study. In: INTERNATIONAL CONFERENCE ON LASER APPLICATIONS IN LIFE SCIENCES, 16th, April 1-2, 2022, Nancy, France. Abstract... Nancy, France: PROGEPI, 2022. p. 124-124.

    Abstract: Nd:YAG lasers emitting λ=1064 nm at microsecond and nanosecond pulses are alternatives to prevent dental caries and erosion in clinics.This wavelength allows most of photons to penetrate deep in the hard tissue due to low absorption of hydroxyapatite in the region. It is necessary to use photoabsorbers so most of photons are absorbed in the surface of the tissue preventing dental pulp necrosis. Currently the coal paste is used as a photoabsorber but the irradiated tissue turns darker what implies in the patients low adherence to the treatment due to aesthetic reasons. [1,2]. Confocal Raman spectroscopy is a non-destructive optical method to obtain detailed information about molecular composition of biological structures in depth. The most prominent feature of Confocal Raman spectroscopy is the reliable capability to provide the biomolecular data with no use of ionizing radiation to penetrate in the sample. This work aims to characterize the dental enamel irradiated with Nd:YAG laser with nanoseconds pulses, in order to describe the depth related changes promoted in the enamel, by the heat generated due to laser irradiation. For these measurements, 30bovine enamel blocks of 8 mm2, were randomized into 3 groups: G1 – enamel untreated; G2 – enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 4 W; 1,05 J/cm2; 5 ns 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G3 -enamel irradiated with Nd:YAG nanopulsed laser ( same parameters as G2) using squid ink as photoabsorber. The assessments of three different depth regions of the cubic shaped samples were: region A- left corner above of the sample, region B- middle of the sample and Region C- right corner below of the sample. The intensity map of phosphate (950 cm-1)regarding the position, were calculated [3,4] as shown in the Figure 01. The comparative results in the Fig.1 demonstrated that application of coal paste associated with Nd:YAG (G2) can preserve the inorganic content better than the squid ink group (G3). These findings have crucial clinical implications in the laser protocol development and itwas possible to correlate the heat penetration depth of the laser irradiation with photoabsorber using the images obtained bythe confocal Raman.

    Palavras-Chave: dentistry; dentin; enamels; lasers; neodymium lasers; yttrium compounds

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  • IPEN-DOC 26009

    CASTRO, PEDRO A.A. de ; ZEZELL, DENISE M. ; MORAIS, MYCHEL R.P.T.; ZORN, TELMA M.. Semi quantitative evaluation of skin burn wound healing: ATR-FTIR study. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: The role of skin wound healing the biochemical mechanisms are still not fully understood and spectroscopy may shine some light on this information. The Fourier Transform Infrared spectroscopy coupled with Attenuated Total Re°ectance (ATR-FTIR) has been demonstrated potential to monitor the biomolecule activity upon biological samples. This work aims to evaluate the feasibility of using ATR-FTIR to discriminate burned skin throughout wound stages. Water vapor at 90±C was applied to the dorsum of Wistar rats resulting in standardized third-degree burns. Tissue samples were collected after 3±, 7±, 14± and 21 days post burn injury. For the acquisition of the spectra, 150 scans were averaged with a resolution of 4 cm¡1 and wavenumbers ranging from 4000 to 400 cm¡1. Analysis of the spectra was calculated using MATLABR°R2015a (MathWorks, Natick, MA) software. Fingerprint region (900 - 1800 cm¡1) and high wavenumber (2800 - 3000 cm¡1) of spectra were o®set-corrected and vector normalized. Area under the curve (AUC) of collagen (1236 cm¡1), amide II (1540 cm¡1), amide I (1632 cm¡1) and lipid (2852 cm¡1) of each group were performed by integration method. The FTIR results exhibit the high biochemical activity of the tissue in the 14o post burn injury when it is compared with control group which correspond to the stage when the new tissue formation is still ongoing. The lipid content decrease in the 21 day, which suggest that the metabolic activity and structural reorganization decrease as the wound healing progress. For future works, micro-FTIR imaging will be used spatially discriminate the bands.

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  • IPEN-DOC 23373

    AMARANTE, MAYARA dos S.; XAVIER, ROSANA S.; LENTE, MANUEL H.; GENOVA, LUIS A. ; BRITO, VERA L.O. de. Sintering study of ferrites, BaTiO3 and their ceramic composites. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... São Carlos, SP: Aptor Software, 2016. p. 732-732.

    Abstract: Traditional solid-state sintering studies of cobalt ferrite are extremely rare in the literature [1]. Differences in thermal coefficients and ultimately lead to delamination, micro-cracking or pore formation in the ceramic materials. Phase changes as a result of sintering (e.g. tetragonal to cubic in BaTiO3) can also contribute to sintering mismatch [2]. Cobalt ferrite and nickel cobalt ferrite powders were prepared using solid-state ceramic processing. Calcination of the ferrite powders was carried out with a heating rate of 5°C/min up to 1050°C and 240 min hold at 1050°C. The calcined powders were uniaxially pressed in the shape of Rectangular bars (20mm X 5mm X 4mm) and cold iso-statically pressed for use as samples for dilatometric thermal analysis. The dilatometry tests of the ferrites, the BaTiO3 (TB), and ferrtite-TB samples were carried out, some samples with constant heating rate and some samples simulating sintering with 2h hold time at a certain temperature. Based on the dilatometry results, sintering thermal cycles for both ferrites and TB were proposed. The microstructure of the sintered samples was evaluated by scanning electron microscopy and their densities were measured by the Archimedes’ method. The results were discussed relating the density and grain size of the samples to the sintering parameters. The same was done with nickel cobalt ferrite and TB to obtain the composite. The sintering study were did to devise a maximum theoretical density of >90%.

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  • IPEN-DOC 23459

    ANA, PATRICIA A.; BENETTI, CAROLINA; BACHMANN, LUCIANO; ZEZELL, DENISE M. . Structural characterization of dentin irradiated with Er,Cr:YSGG laser and fluoride for caries prevention. In: CONFERENCE ON LASERS AND ELECTRO-OPTICS, May 14-19, 2017, San Jose, California, USA. Resumo expandido... Washington, DC, USA: OSA, 2017. p. JTu5A.5.

    Abstract: Er,Cr:YSGG laser induces the formation of bruxite and tetracalcium phosphate, as well as decreases the content of protein and water on dentin tissue, even when associated with a fluoride gel and at low energy densities.

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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.

✔ É possível efetuar a busca de um autor ou um termo em todo o RD, por meio do Buscar no Repositório , isto é, o termo solicitado será localizado em qualquer campo do RD. No entanto esse tipo de pesquisa não é recomendada a não ser que se deseje um resultado amplo e generalizado.

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Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

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Ano de publicação: 2015

✔ Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou 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.