Repositório Digital - IPEN/SP: Recent submissions

  • IPEN-DOC 27113

    MUNAWAR, AISHA; AKREM, AHMED; HUSSAIN, ASHIQ; SPENCER, PATRICK ; BETZEL, CHRISTIAN. Molecular model of cytotoxin-1 from Naja mossambica mossambica venom in complex with chymotrypsin. Theoretical Biology Forum, v. 108, n. 1-2, p. 89-99, 2015. DOI: 10.1400/240197

    Abstract: Snake venom is a myriad of biologically active proteins and peptides. Three finger toxins are highly conserved in their molecular structure, but interestingly possess diverse biological functions. During the course of evolution the introduction of subtle mutations in loop regions and slight variations in the three dimensional structure, has resulted in their functional versatility. Cytotoxin-1 (UniProt ID: P01467), isolated from Naja mossambica mossambica, showed the potential to inhibit chymotrypsin and the chymotryptic activity of the 20S proteasome. In the present work we describe a molecular model of cytotoxin- 1 in complex with chymotrypsin, prepared by the online server ClusPro. Analysis of the molecular model shows that Cytotoxin-1 (P01467) binds to chymotrypsin through its loop I located near the N-terminus. The concave side of loop I of the toxin fits well in the substrate binding pocket of the protease. We propose Phe10 as the dedicated P1 site of the ligand. Being a potent inhibitor of the 20S proteasome, cytotoxin-1 (P01467) can serve as a potential antitumor agent. Already snake venom cytotoxins have been investigated for their ability as an anticancer agent. The molecular model of cytotoxin-1 in complex with chymotrypsin provides important information towards understanding the complex formation.

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  • IPEN-DOC 27112

    HERNANDES, CAMILA; SILVA, BRUNA da; KLINGBEIL, MARIA de F.G. ; MATHOR, MONICA B. ; PEREIRA, ANA M.S.; SEVERINO, PATRICIA. Avoiding chemotherapy resistance in squamous cell carcinomas: anticancer activities of terpenoids and their impact on the regulation of microRNAs. Cancer Research, v. 77, 13 Supplement, 2017. DOI: 10.1158/1538-7445.AM2017-5456

    Abstract: MicroRNAs are small noncoding RNAs that play important roles in cellular biology. They have been implicated in pharmacogenomics by down-regulating genes that are essential for drug function. In this work we verified the potential anticancer activity of the quinone methide triterpenes maytenin and 22-β-hydroxymaytenin, as well as of a quinone methide triterpene-rich extract obtained from cultivated Maytenus ilicifolia root cells, and evaluated the associated microRNA expression following half maximal inhibitory concentration (IC50) treatment. Standard selectivity index (SI) for the isolated compounds and the root cell extract was determined by the logarithmic shift in effective concentration (IC50) between cancer cell lines and oral keratinocytes. Both isolated molecules as well as the root cell extract presented pronounced antiproliferative and pro-apoptotic activities in four cell lines derived from head and neck squamous cell carcinomas, including a metastasis-derived cell line. A positive SI, with an average 2-fold increase in potency, was detected for single agents and for the extract. MicroRNA expression profiles were assessed at 24h, 48h and 72h following treatment and an average of 100 molecules presented consistent marked variation in expression levels. Considering associations of microRNAs, genes they regulate, and the drugs effects dependent on these genes, the down-regulation of miR-193a-3p and miR-21 in treated cells is of particular interest. Both microRNAs have been involved in 5-fluorouracil and cisplatin resistance, current agents of standard chemoradiotherapy for locally advanced head and neck cancer. Squamous cell carcinoma of the head and neck is one of the most common cancer types worldwide whereas treatment options based on conventional therapies or targeted therapies under development have limited efficacy. Plant-derived products are valuable sources for the development of new therapeutic options for cancer treatment or as synergistic agents in existing regular care.

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  • IPEN-DOC 27111

    REIS, S.L. ; MUCCILLO, E.N.S. . Ionic conductivity of doped lanthanum gallate and strontium gallate composites. ECS Transactions, v. 80, n. 9, p. 141-149, 2017. DOI: 10.1149/08009.0141ecst

    Abstract: Polycrystalline ceramic solid electrolytes based on strontium- and magnesium-doped lanthanum gallate exhibit high ionic conductivity and find potential application in solid oxide fuel cells operating at intermediate temperatures. Sintering of this solid electrolyte is usually carried out at high temperatures, being responsible for loss of Ga and consequent formation of impurity phases. In this work, composites consisting of La0.9Sr0.1Ga0.8Mg0.2O3-δ with additions of strontium gallate were prepared by solid state reaction, and the influence of the additiveon electrical conductivity and phase composition of the composite electrolyte was investigated. The sintered density of composites is higher than 95% of the theoretical value after sintering at 1350°C. The contents of impurity phases decreased with increasing additions of strontium gallate. The overall ionic conductivity of the composites is higher than that of LSGM. This effect is attributed to the decrease in the fraction of free MgO at grain boundaries in the composites.

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  • IPEN-DOC 27110

    MONTEIRO, WALDEMAR A. (Ed.) . Light Metal Alloys Applications. Rijeka, Croatia: Intech, 2014. 242 p. DOI: 10.5772/57069

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  • IPEN-DOC 27109

    MONTEIRO, WALDEMAR A. (Ed.) . New Features on Magnesium Alloys. Rijeka, Croatia: Intech, 2012. 174 p. DOI: 10.5772/2810

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  • IPEN-DOC 27108

    MONTEIRO, W.A. ; BUSO, S.J.; SILVA, L.V. da . Application of magnesium alloys in transport. In: MONTEIRO, WALDEMAR A. (Ed.). New Features on Magnesium Alloys. London, UK: IntechOpen, 2012. p. 1-14, cap. 7. DOI: 10.5772/48273

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  • IPEN-DOC 27107

    PEREIRA, VIVIAM S.M.; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V. . Efeito de tratamentos de envelhecimento sobre a resistência à corrosão da liga de magnésio AZ91D / Ageing heat treatments effect on the corrosion resistance of the AZ91D magnesium alloy. In: CONGRESSO INTERNACIONAL ANUAL DA ABM, 67th, July 31 - August 7, 2012, Rio de Janeiro, RJ. Proceedings... 2012. p. 192-202.

    Abstract: O efeito de tratamentos térmicos de envelhecimento (T6) sobre a resistência à corrosão da liga de magnésio AZ91D foi estudado. Amostras solubilizadas a 445°C por 24 h foram envelhecidas a 200 °C por tempos de 8 h, 16 h e 24 h. Todos os tratamentos foram realizados em forno mufla, sob atmosfera inerte (argônio), seguidos de resfriamento em água. Para observação das alterações microestruturais, utilizaram-se as técnicas de microscopia óptica e de MEV. O comportamento eletroquímico foi avaliado por ensaios de espectroscopia de impedância eletroquímica e de polarização potenciodinâmica, utilizando-se solução de Hanks, a 37 °C como eletrólito. O período de imersão foi de 7 dias. Com o tratamento de solubilização, ocorreu a dissolução do constituinte eutético, restando somente a matriz (fase α-Mg) saturada com alumínio, juntamente de resquícios de β- Mg17Al12. Com o tratamento de envelhecimento foram observados precipitados ricos em alumínio (β-Mg17Al12) sobre a matriz. A amostra envelhecida por 8 h foi a que mostrou menor valor de resistência à corrosão; as amostras tratadas por 16 h e 24 h apresentaram valores de impedância semelhantes, sendo que a amostra envelhecida por 16 h apresentou o melhor desempenho.

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  • IPEN-DOC 27106

    RODRIGUES, ANTONIO C.I. ; MADI FILHO, TUFIC ; SILVA, DAVILSON G. da . Analysis and construction of the high density storage racks for spent fuel of the research reactor IEA-R1. RAD Conference Proceedings, v. 3, p. 123-126, 2018. DOI: 10.21175/RadProc.2018.27

    Abstract: The IEA-R1 research reactor works 40h weekly, with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions, the reactor operating for 32h/week will have 3 spent fuel by year, approximately 3 utilization rate Positions/year; thus, we will have only about six years of capacity for storage. Since the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel by doubling the wet storage in the reactor’s pool. 3M’s neutron absorber BoralcanTM was chosen after reviewing the literature about available materials for the construction of a new storage rack. This work presents studies for the construction of new storage racks with double of capacity using the same place of the current ones. Criticality safety analysis was performed with MCNP-5 Monte Carlo code, using two Evaluated Nuclear Data Files (ENDF/B-VI and ENDF/B-VII) in calculations, and subsequently, the results were compared. The full charge of the storage rack with only new fuel elements (maximum reactivity) was considered to calculate the keff. The results obtained in the simulations show that it is possible doubling the storage capacity of the spent fuel elements. Additionally, it complies with safety limits established by International Atomic Energy Agency (IAEA) and Brazilian Commission of Nuclear Energy (CNEN) standards to the criticality criteria (keff <0.95). This is only possible with the use of neutron absorber material.

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  • IPEN-DOC 27105

    OTON, LAIS F.; OLIVEIRA, ALCINEIA C.; ARAUJO, JESUINA C.S. de; ARAUJO, RINALDO S.; SOUSA, FRANCISCO F. de; SARAIVA, GILBERTO D.; LANG, ROSSANO; OTUBO, LARISSA; DUARTE, GIAN C. da S.; CAMPOS, ADRIANA. Selective catalytic reduction of NOx by CO (CO-SCR) over metal-supported nanoparticles dispersed on porous alumina. Advanced Powder Technology, v. 31, n. 1, p. 464-476, 2020. DOI: 10.1016/j.apt.2019.11.003

    Abstract: The selective catalytic reduction of NOx by CO (CO-SCR) was investigated over metals supported on porous alumina. The Pt, Co, Fe and Ni nanoparticles were dispersed on the alumina and characterized by XRD, textural properties, FTIR spectroscopy, chemical analyses, Py adsorption followed by FTIR measurements, HRTEM and SEM-EDS. Among the solids studied, the Pt/Al2O3 and NiPt/Al2O3 catalysts exhibited improved performance due to the interaction and synergy between the Pt(Ni) nanoparticles and the support. In other words, the electron transfer facility between the PtOx(Ni) and chlorined Pt species on the support provided a more active solid in the CO-SCR reaction. The surface acidity of Lewis acid sites and the porous features of the Pt/Al2O3 and NiPt/Al2O3 catalysts also contributed significantly to the high performance of these materials in the NOx conversion. The Pt/Al2O3 and NiPt/Al2O3 catalysts were tolerant to the poisoning by SO2 and H2O and depicted a superior catalytic performance, compared to the other solids.

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  • IPEN-DOC 26678

    CABRAL, FERNANDA V. ; SABINO, CAETANO P.; DIMMER, JESICA A.; SAUTER, ISMAEL P. ; CORTEZ, MAURO J.; RIBEIRO, MARTHA S. . Preclinical investigation of methylene blue-mediated antimicrobial photodynamic therapy on Leishmania parasites using real-time bioluminescence. Photochemistry and Photobiology, v. 96, n. 3, p. 604-610, 2020. DOI: 10.1111/php.13188

    Abstract: Cutaneous leishmaniasis (CL) is a neglected disease that promotes destructive lesions. Difficulties in treatment are related to accessibility of drugs, resistance and toxicity. Antimicrobial photodynamic therapy (APDT) has been emerging as a promising treatment for CL. In this work, we evaluated methylene blue (MB)-mediated APDT (MB-APDT) on Leishmania amazonensis in vitro and in vivo by bioluminescence technique. In vitro, MB-APDT was performed using a red LED (k = 660 11 nm, 100 mW cm 2) and MB (100 μM) at different light doses. In vivo, mice were infected and 4 weeks later, randomly divided into three groups: control, APDT 1 (single session) and APDT 2 (two sessions of MB-APDT). MB was used at 100 μM and energy dose was established at 150 J cm 2. Parasite burden, lesion size and pain were evaluated weekly for 4 weeks. In vitro, lethal dose for 90% parasite inactivation was achieved at 48.8 J cm 2. In vivo, although APDT 1 and APDT 2 groups have showed similar parasite burden after 4 weeks, two sessions were clinically better, especially considering the inflammatory process associated to CL. Our findings reinforce MB-APDT as a costeffective treatment to combat CL.

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  • IPEN-DOC 26454

    LOBO, ALEXANDRE R.; GAIEVSKI, EDUARDO H.S.; MESQUITA, CARLOS H. de ; DE CARLI, EDUARDO; TEIXEIRA, PRYSCILA D.S.; PEREIRA, ROSA M.R.; BORELLI, PRIMAVERA; SÁ, LILIAN R.M. de; COLLI, CELIA. Increased adiposity by feeding growing rats a high-fat diet results in iron decompartmentalisation. British Journal of Nutrition, v. 123, n. 10, p. 1094-1108, 2020. DOI: 10.1017/S0007114519002320

    Abstract: The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue ‘i’ to tissue ‘j’) adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ki;j ¼ a ×Mb. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.

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  • IPEN-DOC 25779

    AZEVEDO, JULIANA de S.; QUINTINO, MARILIA T.A.; ROGERO, SIZUE O. ; ZAMPIERI, MARIA C.T. ; ROGERO, JOSE R. . Histopathological changes in zebrafish exposed to sublethal concentrations of 89nm silver nanoparticles for application in environmental diagnostics. Human and Ecological Risk Assessment, v. 26, n. 5, p. 1207-1220, 2020. DOI: 10.1080/10807039.2018.1560219

    Abstract: The use of biomarkers as indicators of environmental contamination has been shown to be an excellent indicator of changes in biota. Histopathological lesions are commonly used in biomonitoring studies as they provide information regarding both acute and chronic exposure. The use of nanoparticle materials has been widespread in recent years. However, not much is known about their ecological effects on the natural environment. Thus, the aim of this study was to assess the sublethal effects of silver nanoparticles (AgNP) with mean diameters of 89nm in the zebrafish Danio rerio by the determination of the LC50; 48 h and histopathological assays in gills. The obtained LC50; 48 h was 8.18 mgL 1. The histopathological gill assessment showed primary responses indicative of acute damage as aneurysms (32.76%), hyperplasia (20.69%) and partial (30.17%) and total lamellar fusion (6.9%) of secondary lamellae. No deposition of AgNP was observed in any tested sample gills, suggesting other organs target to absorption and detoxification. In fact, the AgNP causes sublethal damage in the gills of zebrafish but is not able to accumulate in this tissue. Finally, the data shown in this study contribute to the construction of a database on the AgNP exposure in aquatic organisms.

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  • IPEN-DOC 25761

    BOIDI, G.; TERTULIANO, I.S.; PROFITO, F.J.; ROSSI, W. de ; MACHADO, I.F.. Effect of laser surface texturing on friction behaviour in elastohydrodynamically lubricated point contacts under different sliding-rolling conditions. Tribology International, v. 149, p. 1-9, 2020. DOI: 10.1016/j.triboint.2019.02.021

    Abstract: The Laser Surface Texturing (LST) technique has been largely investigated to improve the tribological performance of lubricated contacts. The present contribution is aimed at scrutinizing the influence of three texture configurations fabricated by LST on the tribological performance of elastohydrodynamic (EHD) point contacts under different slide-to-roll ratios (SRR), entrainment velocities and inlet temperatures. Friction experiments were conducted through a series of ball-on-disk tests in the MTM-2 (Mini-Traction Machine) tribometer. Main results showed that the texture configurations promoted significant effects under boundary and mixed lubrication conditions, and also affected the full-film EHD regime at higher temperatures. Furthermore, the tribological performance of textured samples was strongly related to the texture depth. Shallower texture designs (∼0.5 μm) reduced friction compared to untextured material, whereas deeper features (> 1 μm) generally led to detrimental results. In general, dimples configuration decreased the lift-off speed and promoted full-film EHD conditions for a larger range of speeds, whereas radial curved grooves yielded to friction reduction under mixed lubrication conditions, moving the transition from boundary to mixed regimes to lower speeds, especially for intermediate lubricant viscosity.

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  • IPEN-DOC 27104

    SANTOS, G.A. dos; FIGUEIREDO, W.; SCHMITT, Y.P.; NASCIMENTO, M.S.; MIRANDA, F.; BATALHA, G.F.; COUTO, A.A. . Study on closed-die forging in stainless steel as standard ASTM F138 in grain size function. In: ÖCHSNER, ANDREAS (Ed.); ALTENBACH, HOLM (Ed.). Engineering Design Applications II: Structures, Materials and Processes. Cham, Switzerland: Springer Nature Switzerland, 2020. p. 133-153, (Advanced Structured Materials, 113). DOI: 10.1007/978-3-030-20801-1_10

    Abstract: Forging is a bulk deformation process in metal working commonly employed in the manufacture of metallic materials prostheses. Depending on the compressive loads applied to the material, structures (grain sizes) are formed which increase its strength. By forging an ASTM F138 stainless steel, the heating of material in a suitable temperature is of fundamental importance to be formed without the presence of folds arising from the process and as a result we can obtain a proper microstructure. This work aims to define the accurate temperature in relation to the strain rate applied in the hot die forging process. Besides, it is used a closed-die forging in which cavity has different thickness that stimulates the profile of an orthopedic plate. Four ranges of temperature used in the process vary between 1000 and 1200 °C, with a strain rate ranging from 400 to 600 s−1.Results demonstrate that there is a transitional temperature close to 1050 °C, where temperatures of 1000–1040 °C provide satisfactory grain size and temperatures of 1100 and 1200 °C, showed limitations in grain size, greater than those recommended by ASTM F 621.

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  • IPEN-DOC 27103

    MACHADO, ALESSANDRA C.F.E. (Ed.); HONÓRIO, DANIEL H. (Ed.); PEREIRA, DÉBORA A. (Ed.); LIMA, ADRIANA T. de (Ed.); AQUINO, AFONSO R. de (Ed.); CORDOVIL, CLEBER de S. (Ed.); NICOLETTI, HENRIQUE P. (Ed.); SANTOS, JOSÉ R. (Ed.); SILVA, KARINA M. da (Ed.); MAIA, LUIZ C. (Ed.); POPST, LUIZ A.A. (Ed.); SANTOS, MARIA L.D.P. (Ed.); SANTOS, MARIANA (Ed.); WILLMERSDORF, OFÉLIA de F.G. (Ed.); DIAS, PAULO E.V. (Ed.); SARACURA, VALÉRIA F. (Ed.); COIMBRA, VINÍCIUS P. (Ed.) . I Workshop sobre Educação Ambiental: Resultados e Encaminhamentos. Brasília, DF; Araçoiaba da Serra, SP: ICMBio; FLONA de Ipanema, 2018. 112 p.

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  • IPEN-DOC 27102

    INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES (Ed.); SAKATA, SOLANGE K. (Coord.); RODRIGUES, DEBORA F. (Coord.); OYANEDEL-CRAVER, VINKA (Coord.) . Conference Proceedings of 1st Pan American Congress of Nanotechnology: Fundamentals and Applications to Shape the Future - PanNano 2017. São Paulo, SP, 2018. 257 p.

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  • IPEN-DOC 27101

    MIZUTANI, GUSTAVO ; VEGA, OSCAR . Análise de agrotóxicos em alimentos vegetais com alto teor de proteínas via cromatografia acoplada a espectrometria de massas tandem. In: CONGRESSO ANALITICA, 6th.; CONGRESSO ANALITICA LATIN AMERICA, 15th.; NANO TRADE SHOW; CIRCUITO DO CONHECIMENTO E INOVAÇÃO, September 24-26, 2019, São Paulo, SP. Poster... 2019.

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  • IPEN-DOC 27100

    CARVALHO, ELIAS F. ; OSTERMANN, CAROLINE K. ; BUSTILLOS, JOSE O.V. . Vertical profile analysis of wind flow to obtain optimal eddy covariance parameters. In: ATTO WORKSHOP, 3rd, September 16-20, 2019, Manaus, AM. Poster... 2019.

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  • IPEN-DOC 27099

    OSTERMANN, CAROLINE ; ZANNONI, NORA; CARVALHO, ELIAS ; NOVAES, MARIANA ; WILLIAMS, JONATHAN; VEGA, OSCAR . Exploring chiral BVOCs in Amazon and Atlantic forest by TENAX® and Carbograph® sorbent. In: LATIN AMERICAN SYMPOSIUM ON ENVIRONMENTAL ANALYTICAL CHEMISTRY, 14th; ENCONTRO NACIONAL DE QUÍMICA AMBIENTAL, 9.; WORKSHOP EM AVANÇOS RECENTES NO PREPARO DE AMOSTRAS, 12.; SEMINÁRIO CORSAN DE PESQUISA E INOVAÇÃO, 2., November 6-8, 2019, Bento Gonçalves, RS. Poster... 2019.

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  • IPEN-DOC 27098

    NAKANO, V.E.; OSSUGUI, M.; FERREIRA, C.P.; SANTA CRUZ, L.M.; COSTA, A.R.; KIMURA, I.A.; BUSTILLOS, J.O.W.V. ; ALABURDA, J.. Método multirresíduo de agrotóxicos em água destinada ao consumo humano por LC-HRMS (ORBITRAP™). In: LATIN AMERICAN SYMPOSIUM ON ENVIRONMENTAL ANALYTICAL CHEMISTRY, 14th; ENCONTRO NACIONAL DE QUÍMICA AMBIENTAL, 9.; WORKSHOP EM AVANÇOS RECENTES NO PREPARO DE AMOSTRAS, 12.; SEMINÁRIO CORSAN DE PESQUISA E INOVAÇÃO, 2., November 6-8, 2019, Bento Gonçalves, RS. Abstract... 2019.

    Abstract: O presente trabalho apresenta um método simples e rápido para a determinação por injeção direta de 68 ingredientes ativos (i.a.) de agrotóxicos em água para consumo humano, empregando cromatografia líquida acoplada ao espectrômetro de massas de alta resolução (LC-HRMS/Orbitrap). A técnica por injeção direta dispensa o tratamento prévio ou concentração da amostra, reduz o consumo de solventes e elimina possíveis perdas de analitos. O analisador de massas Orbitrap possui resolução e sensibilidade elevadas, alta especificidade na identificação de compostos por meio da massa exata e permite a determinação simultânea de resíduos de agrotóxicos de diferentes classes e propriedades físico-químicas. Para a identificação e quantificação dos i.a. foi utilizado cromatógrafo a líquido de ultraperformance (UHPLC) Ultimate 3000 Dionex acoplado ao analisador de massas Exactive Plus Orbitrap™ Thermo Scientific, coluna analítica Hypersil Gold C18 aQ Thermo Scientific, fonte de ionização por electrospray com aquecimento (HESI) e aquisição dos dados nos modos positivo e negativo. O erro aceitável de exatidão de massas foi de até 5ppm. O método foi realizado em Full MS e All Ion Fragmentation (AIF), numa faixa de massas entre 60 e 900m/z com resolução de aquisição de 35000 e 17500, respectivamente, tempo de análise de 12minutos. Para as análises, à amostra de água foram adicionados ácido fórmico 0,1% (v/v) e metanol 0,5% (v/v). A validação do método multirresíduo foi realizada por ensaios de recuperação, avaliando exatidão, precisão, linearidade, limites de detecção (LD) e de quantificação (LQ). A avaliação de desempenho e critérios de aceitação foram baseados nos descritos da SANTE 11813/2017. As curvas analíticas para todos os compostos foram obtidas em triplicata, na faixa de concentração de 0,2 a 50 μg.L-1, com exceção dos i.a. atrazina e simazina, cuja faixa de trabalho foi de 0,06 a 16 μg.L-1. Os limites de detecção e de quantificação foram estabelecidos por estudos estatísticos e variaram de 0,19 a 2,12 μg.L-1, e de 0,56 a 6,53 μg.L-1, respectivamente. Os valores de LQ obtidos dos ativos constantes na Portaria de Consolidação MS-GM nº 05/2017 (Brasil, 2017) analisados neste trabalho estão abaixo dos limites máximos estabelecidos. Sob condições de repetibilidade (N=5), as médias das recuperações dos i.a. nos níveis de fortificação 0,5; 1; 2; 5 e 40μg.L-1, e para a atrazina e simazina em 0,16; 0,32; 0,64; 1,6 e 12,8μg.L-1, variaram de 75,07% a 123,06% e DPR de 0,74 a 23,02%. As amostras em branco não apresentaram interferentes dos compostos estudados (efeito matriz). O método multirresíduo para análise de 68 i.a. de agrotóxicos por injeção direta em LCHRMS mostrou-se eficiente, simples, rápido, sensível e confiável para a análise de amostras de água. A implantação da metodologia terá aplicações relevantes para a área de Saúde Pública e permitirá o desenvolvimento de novas pesquisas referentes à contaminação de água para consumo humano. Os resultados obtidos poderão subsidiar as ações de vigilância sanitária, bem como proporcionar dados que contribuam e incentivem a revisão das legislações vigentes.

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  • IPEN-DOC 27097

    FERREIRA, WANDERSON L. ; PEREIRA, LUCIANO F.D. ; COSTA, MESSIAS de S.; SCALISE, LEVY ; GONÇALVES, VITOR C. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Investigation on the role of oxygen vacancies in the Cd hyperfine properties in (Co, Mn)-doped CeO2. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 86-86.

    Abstract: Ceria is known to have intrinsic oxygen vacancies that affect specific properties for semiconductor applications. Recently, incorporation of impurities to ceria for vacancy formation control as well as the role of dopants in the physical and chemical ceria properties have gained much attention, especially when doped with transition metals. Local disorder originated from oxygen vacancies and doping is the aim of several studies in which hyperfine interactions techniques have showed a great tool to investigate it. In particular, perturbed angular correlation spectroscopy (PAC) measurements with 111Cd for pure and TM (Co, Mn)-doped CeO2 have exhibited a range of quadrupole frequencies [1, 2]. In order to elucidate the several electric field gradients (efg) in these systems, we have carried out band structure calculations by means of density functional theory (DFT) in the ceria doped with Cd and TM (Co, Mn) to study the local disorder from the hyperfine interactions point of view. We performed spin-polarized calculation using the full-potential augmented plane-waves plus local-orbitals (FP-LAPW) method and Perdew–Burke–Ernzerhof generalized gradient approximation embodied into WIEN2k code [3]. We simulated several charge states in pure and TM-doped CeO2 supercells with oxygen vacancies focusing on electronic distribution in the vicinity of Cd. Our efg results showed a good agreement with 111Cd quadrupole frequency range obtained from PAC experiments. Thus, we improved the understanding about the role of Cd and TM in the ceria oxygen vacancy formation.

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  • IPEN-DOC 27096

    BURIMOVA, A. ; CARBONARI, A.W. ; RICHARD, D.; PEREIRA, L.F.D. ; GENEZINI, F.A. . Mechanisms of reduction in V2O5 and MoO3 studied by PAC spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 59-59.

    Abstract: Structural evolution of vanadium (V) and molybdenum (VI) oxides with temperature was studied by Time Differential Perturbed Angular Correlation (TDPAC) spectroscopy in different atmospheres with 111Cd probe incorporated by wet impregnation. In case of V2O5 sealed in vacuum, the critical temperature for probe diffusion was found to be above 500oC, whereas for MoO3 this barrier was 600oC. The diffusion was suppressed in low pressure oxygen atmosphere. The behavior of hyperfine parameters on heating to melting point of V and Mo oxides and subsequent cooling to room temperature was analyzed. TDPAC results were complemented by X-ray diffraction data. We discuss comproportionation, topotactic, competitive and consecutive mechanisms as the candidates to describe V2O5 → VO2 and MoO3 → MoO2 reduction.

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  • IPEN-DOC 27095

    DARRIBA, G.N.; RICHARD, D.; MUÑOZ, E.L.; RUNCO, J.; CARBONARI, A.W. ; PETRILLI, H.M.; RENTERIA, M.. Dynamic hyperfine interactions in (111In→)111Cd-doped SnO2 and SnO semiconductors: ab initio approach to the electron-capture after-effects phenomenon. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 103-103.

    Abstract: In the PAC literature, the so-called “after-effects” phenomenon refers to the electronic relaxations processes of a probe-atom following the electron-capture (EC) nuclear-decay of its radioactive parent. This effect has been observed in PAC experiments on semiconducting and insulating oxides doped with 111In(→111Cd), through the existence of dynamic hyperfine interactions (i.e., with time-dependent anisotropies), dependent and reversible with measuring temperature. We present here results of PAC experiments in (111In →)111Cd-doped SnO2 and SnO that have been successfully analyzed with a time-dependent on-off model for the perturbation factor. These results showed combined dynamic plus static hyperfine interactions whose electric-field gradients (EFG) were associated to different stable electronic configurations close to the 111Cd nucleus. The dynamic regime is originated in fast fluctuations between these different electronic configurations. Density functional theory-based electronic-structure calculations of Cd-doped SnO2 and SnO were performed as a function of the charge state of the impurity. In SnO2, the impurity introduces a double acceptor level in the top of the valence band together with isotropic outward relaxations of the nearest oxygen neighbors. The variation of the calculated EFG tensor as a function of the charge state of the Cd impurity level shows an interesting behavior that explains the experimental results, giving strong support from first principles to the electron-capture after-effects proposed scenario. A similar ab initio analysis in Cd-doped SnO, in which Cd is nominally an isovalent impurity, also gave account succesfully of the experimental results. The EC decay of 111In to 111Cd and the electric nature of the host are shown to contribute to the existence of these types of time-dependent hyperfine interactions, showing that the acceptor character of the impurity seems not to be a necessary condition to produce after effects at least in Sn oxides.

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  • IPEN-DOC 27094

    SANTOS, R.A. ; SANTOS, B.B. ; CORREA, E.L. ; PEREIRA, L.F.D. ; SCHELL, J.; CORREIA, J.G.M.; LUPASCU, D.C.; SCHAAF, P.; HOFSAESS, H.C.; SAXENA, R.N. ; CARBONARI, A.W. . Hyperfine interactions measurements in bismuth tri-iodide (BiI3) by time differential perturbed angular correlation spectroscopy (TDPAC). In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 101-101.

    Abstract: Bismuth tri-iodide (BiI3) is a material of great interest in applications such as solar cells and semiconductor detectors. In the work reported here, bulk samples of BiI3 were characterized by time differential perturbed angular correlation spectroscopy (TDPAC) at different temperatures using 111mCd (111Cd) and 111In (111Cd) as radioactive probes, inserted by implantation at ISOLDE/CERN and by thermal diffusion at IPEN, respectively. TDPAC measurements were used to investigate the hyperfine interactions at Bi sites in the crystalline structure of BiI3. The hyperfine parameters obtained were analyzed to elucidate the electrical properties expected for the mentioned technological applications. The optimal temperatures for annealing after the implantation (300°C and 320°C) were determined, allowing to observe the perturbation pattern R(t). Measurements show that the incidence of UV light at 350–363nm wavelength has an effect on the electronic structure around the Cd probe nuclei located near the surface of samples.

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  • IPEN-DOC 27093

    PEREIRA, LUCIANO F.D. ; MESTNIK-FILHO, JOSE ; CABRERA-PASCA, GABRIEL A. ; BOSCH-SANTOS, BRIANNA ; FERREIRA, WANDERSON L. ; GONÇALVES, VITOR C. ; SCALISE, LEVY ; GENEZINI, FREDERICO A. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Insights into anomalous magnetic hyperfine field at Ce impurity in LaMn2X2 (X=Si, Ge): a study from first principles calculations. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 88-88.

    Abstract: The LaMn2X2 (X=Si, Ge) intermetallic compounds doped with cerium exhibit the interesting physical effects that are typical of the REMn2X2 (RE=rare earth) series (such as magnetocaloric, superconductivy) or are originated from cerium in specific electronic environment (e.g. Kondo, intermediate valence, strongly correlated electron). Recently, the magnetic hyperfine field (mhf) at 140Ce-doped LaMn2(Si(1-x)Gex)2 was determined by perturbed gamma-gamma angular correlation spectroscopy. The 140Ce mhf follow the host magnetization in LaMn2Si2, while in LaMn2(Si(1-x)Gex)2 (with x = 0.2 up to 1), it has anomalous behaviour, which was associated with 4f cerium mhf contribution. In this work, first principles band structure simulations were used to improve the understanding of the distance role (generated by interchange of Si and Ge) on mhf cerium contribution.

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  • IPEN-DOC 27092

    PEREIRA, LUCIANO F.D. ; FERREIRA, WANDERSON L. ; GONÇALVES, VITOR C. ; SCALISE, LEVY ; GENEZINI, FREDERICO A. ; CORREA, EDUARDO L. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Hyperfine interactions in Gd2Ti2O7 pyrochlore: ab initio calculations. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 87-87.

    Abstract: The cubic pyrochlore structure of the RE2Ti2O7 (R= rare earth) form is highly geometrically frustrated antiferromagnets and Gd2Ti2O7 is particularly interesting due to the fact gadolinium has a large magnetic moment and its orbital momentum is zero. Up to nowadays, a few investigations of the local structure on Gd2Ti2O7 using hyperfine interactions techniques were made. Namely, the magnetic hyperfine interaction at Gd previously reported from Mossbauer effect spectroscopy with 155Gd [1] and perturbed angular correlation (PAC) have used to reach electric field gradient at 111mCd and 111In probe nuclei [2]. However, these studies are lacking in interpretation, so first principles calculations may led to the elucidation of the electronic structure at the specific crystalline site. Then, Gd2Ti2O7 single and doped-Cd cell simulations have performed with full potential linearized augmented plane waves methods and generalized gradient approximation from Perdew-Burke-Ernzerhorf within the WIEN2k code. Electric field gradient and magnetic hyperfine components were evaluated.

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  • IPEN-DOC 27091

    SALES, T.S.N. ; SAXENA, R.N. ; CARBONARI, A.W. . Study of the hyperfine parameters in Si and Fe doped HfO2 nanoparticles by perturbed angular correlation spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 83-83.

    Abstract: Nanoparticles (NPs) have attracted a great deal of interest due to their desirable properties suited for technological and medical applications. Hafnium dioxide (HfO2) can be used in both areas. HfO2 NPs were synthesized through sol-gel method, which allows an efficient and controlled doping of HfO2. In this work, we have investigated the effect of (5% at.) doping of HfO2 NPs with Si and Fe by measuring hyperfine interactions at 181Ta probe nuclei on Hf sites using the perturbed γ–γ angular correlations (PAC) spectroscopy. The structural and morphological analysis was carried out by X-ray diffraction (XRD) and transmission microscopy (TEM) techniques. For both samples, XRD results showed a single phase with the expected monoclinic structure and TEM results indicated NPs with an average diameter of approximately 30 nm. The hyperfine parameters were measured in the temperature range of 200-900 ºC. The radioactive 181Hf was produced by irradiating the samples with neutrons in the IEA-R1 reactor at IPEN. The samples were enclosed in the alumina tube instead of usual silica tube to avoid the formation of hafnon. Results of both samples showed that probe nuclei occupy three sites with different electric quadrupolar interactions. The major fractions (~65%), in both cases however, showed the well-known monoclinic structure of pure HfO2 [1]. The characterization of one of the minor fractions in Si doped HfO2 showing a tetragonal structure between 400-600 ºC is discussed.

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  • IPEN-DOC 27090

    CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; CARVALHO JUNIOR, R.N.; SAXENA, R.N. ; CARBONARI, A.W. . Hyperfine interaction study of iron oxide nanoparticles coated with Amazon ucuúba, bacaba and açaí, oils by PAC spectroscopy using 111In-111Cd nuclear probe nuclei. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 82-82.

    Abstract: The use of nanoparticles coated with different materials have been the subject of study by many researchers to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work we used ucuúba (virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) oils to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native tree of the Amazon forest, whose oils are rich in fatty acids present in different proportions, such as, lauric, myristic, steatic, oleic, palmitic, and linoleic acid. These pure oils, free of solvents, were obtained by the extraction method with carbon dioxide in the supercritical state [2], and added during the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The samples were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Perturbed Angular Correlation (PAC) spectroscopy. The XRD results confirmed the formation of Fe3O4 phase. The TEM results determined the average size to be (> 5 nm) and possible spherical morphology of the magnetite nanoparticles. In order to perform the PAC measurements, 111In-111Cd probe nuclei were diffused in the powder samples at 973 K for 2.5 h. PAC measurements permitted the determination of electric quadrupole and magnetic dipole -hyperfine parameters as a function of temperature. The Curie temperature in each case was determined to be ~ 855 K.

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  • IPEN-DOC 27089

    PAES, S.C.; CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; SAXENA, R.N. ; CARBONARI, A.W. . Effects of surfactant on the morphology of α-Bi2O3 synthesized by the Sol-gel method: hyperfine interaction study by PAC spectroscopy using 111In-111Cd nuclear probe nuclei. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 81-81.

    Abstract: Nano and micromaterial research, with a well-defined size and shape, has attracted attention from researchers in the areas of chemistry, physics, engineering and biomedicine, due to the wide range of possible applications such as: health, environment, catalysis and miniaturization of electronic devices. In this sense, the chemical routes of synthesis, such as Sol-Gel, are more prominent because it allows the production of particulate materials and thin films, with controllable size and morphology. In this work, bismuth oxide microparticles were synthesized by the Sol-Gel method using metallic bismuth (99.999% purity) in acid solution. Initially, bismuth was diluted with nitric acid solution and distilled water. After dilution, citric acid (600 mg) and ethylene glycol were added. The volume of ethylene glycol was varied from 1 to 3.75 mL, in order to study the morphological effects of its concentration. The samples were then subjected to the calcination process at 673 K for 12 hours. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and Raman spectroscopy. The XRD diffractograms and the Raman spectrum vibration bands showed that the synthesized samples correspond to the bismuth oxide in the alpha phase (α-Bi2O3) [1-3]. The EDS results show typical elements of bismuth oxide, without contaminants. The SEM images revealed different morphologies, ranging from the formation of flakes to microspherical particles with good size distribution (diameter 0.7 and 2.0 μm). All samples have a crystalline structure and vibration modes corresponding to the α-Bi2O3 phase, but these have totally different morphologies, which proves the dependence of the morphology with the concentration of ethylene glycol. In order to perform the PAC measurements, 111In-111Cd probe nuclei were diffused in the samples during synthesis. PAC measurements permitted the determination of electric quadrupole - hyperfine parameters as a function of temperature, from 50 to 673 K.

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  • IPEN-DOC 27088

    CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; CARVALHO JUNIOR, R.N.; SAXENA, R.N. ; CARBONARI, A.W. . Study by perturbed angular correlation spectroscopy with 111In-111Cd of iron oxide nanoparticles synthesized using Amazon ucuúba, bacaba and açaí, oils. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 80-80.

    Abstract: The use of nanoparticles coated with different materials are also a subject of study by many scientists to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work was used ucuúba (virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) oils to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native tree of the Amazon forest, whose oils is rich in fatty acids present in different proportions, such as, lauric, myristic, steatic, oleic, palmitic, and linoleic acid. These pure oils, free of solvents, was obtained by the extraction method with carbon dioxide in the supercritical state [2], and added to the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The samples were characterized by X-ray diffraction (XRD), it was possible to verify the formation of Fe3O4 nanoparticles by the position and width of the intensity peaks. Transmission electron microscopy (TEM) were used to observe the average size (> 5 nm) and possible spherical morphology of the magnetite nanoparticles. In order to perform perturbed angular correlation spectroscopy (PAC) the powder samples were heated at 973 K for 2,5 h to diffuse the 111In-111Cd probe nuclei. Using this technique, it is possible determine the electric quadrupole and magnetic dipole hyperfine parameters of the samples as a function of temperature, and it was determined the Curie temperature of ~ 855 K for both samples. The results showed that it is possible synthesized Fe3O4 nanoparticles using ucuúba, bacaba and açaí oils.

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  • IPEN-DOC 27087

    KRYLOV, V.I.; BOSCH-SANTOS, B. ; CABRERA-PASCA, G.A. ; CARBONARI, A.W. ; SAXENA, R.N. ; LEITE NETO, O.F.S. . Magnetic hyperfine field at 119Sn and 111Cd probes in Gd5Ge4 studied by Mössbauer and PAC spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 39-39.

    Abstract: The magnetic structure of Gd5Ge4 belonging to the family of giant magnetocaloric Gd5(Si1-xGex)4 alloys [1] has been examined by magnetization measurements in single crystal [2, 3], X-ray resonant magnetic scattering (XRMS) [4], and neutron powder diffraction (NPD [5]. Gd5Ge4 crystallizes in the orthorhombic structure (space group Pnma) having three non-equivalent Ge-sites. At low temperatures, the Gd magnetic moments are ferromagnetically (FM) aligned within the slabs along the c-direction, while their stacking in the b-direction is antiferromagnetic (AFM) below 127 K [2, 4]. In this work, the temperature dependence of the magnetic hyperfine field (HF) and electric quadrupole interaction on 119Sn and 111Cd probe nuclei in Gd5Ge4 compound have been investigated by Mössbauer and perturbed angular correlation (PAC) spectroscopy. At the saturation, the HF magnitudes reach of Bhf =28.0(5) T and Bhf= 12.6(5) T for 119Sn and 111Cd, respectively, which correspond to the FM local magnetic environment for these probes. It was found that 119Sn probes are placed in two Ge positions, whereas 111Cd probes are located in only one of the three Ge positions in Gd5Ge4. Temperature dependence of Bhf for both 119Sn and 111Cd probes in Gd5Ge4 present anomalous behavior. In the range from 20 K to 120K, the HF decreases almost linearly when temperature increases. These anomalous behavior of Bhf(T) for 119Sn and 111Cd probes are in agreement with the temperature variation of the magnetic (070) and (010) peak intensities that have been found in XRMS [3] and NPD [4] studies. The AFM ordering temperature of Gd5Ge4, TN=129(1) K, found from the Bhf (T) is in agreement with previous results of [2 - 5]. Changes of the values and sign of the quadrupole shift of Mössbauer spectra for 119Sn atoms with the increase of temperature from 30 to 50 K confirm the spin-flop transition in Gd5Ge4 [2, 4].

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  • IPEN-DOC 27086

    MATOS, I.T. ; NASCIMENTO, N.M. ; CABRERA-PASCA, G.A.; EFFENBERGER, F.B. ; FREITAS, R.S.; CARBONARI, A.W. . Investigation of magnetic and structural properties of CoFe2O4 nanoparticles by measuring hyperfine interactions with 111Cd. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 35-35.

    Abstract: Because their ability of magnetic nanoparticles (MNP) to become magnetized when exposed to an external magnetic field, which make them good candidates for biomedical applications [1]. The investigation of the magnetic and structural properties by techniques with atomic resolution, such as those based on hyperfine interactions, is, therefore, greatly useful in the study of MNP. In this work, hyperfine interactions in nanoparticles of CoFe2O4 were investigated by perturbed γ-γ angular correlation (PAC) spectroscopy using 111Cd as probe nuclei in the temperature range from 50 K to 850 K. Samples of CoFe2O4 were prepared by thermal decomposition [2]. Magnetic measurements results show a blocking temperature of 210 K and a superparamagnetic behavior at 300 K. MET measurements show that particles present well-monodispersed spherical shape with average size of 7 nm. XRD results show that samples crystallize in a single phase with the expected spinel structure. PAC spectra were fitted by a model considering two site fractions occupied by the probe nuclei. One were characterized by a single well-defined Larmor frequency with site fraction population of 47%, which was assigned to probe nuclei substituting cation sites in the core region of the particles. The other was characterized by a broad distribution quadrupole frequency with population of 53% corresponding to probe nuclei at distorted cation sites in the shell region of the particles. This assignment agrees with an expected shell/core volume ratio for particles with a diameter of 7 nm. Hyperfine measurements also show that the magnetic hyperfine field (Bhf) is 12.6 T at 10 K in the saturated region and the temperature dependence of Bhf indicate that the transition temperature is around 900 K.

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  • IPEN-DOC 27085

    MADI FILHO, TUFIC ; FERREIRA, ELSON B.; PEREIRA, MARIA da C.C. ; BERRETTA, JOSE R. . The use of the neutron activation analysis technique to determine heavy metals in Nicotiana tabacum solanaceae. In: INTERNATIONAL CONFERENCE ON RADIATION AND APPLICATIONS IN VARIOUS FIELDS OF RESEARCH, 6th, June 18-22, 2018, Ohrid, Macedonia. Abstract... Niš, Serbia: RAD Association, 2018. p. 348-348.

    Abstract: Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability and tobacco smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have researched about heavy metals and the toxicity of tobacco. Heavy metals are frequently found in low concentrations in ground, superficial and underground waters, even though it does not have environmental anthropogenic contributions. However, with the increase of the industrial activities and mining and the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of heavy metals increases the release of these elements into the biosphere, where they are frequently accumulated in the superior layer of the ground, accessible to the roots of the plants. Traces of available heavy metals may be found in surface and subsurface aquatic systems and soils, even when there is no anthropogenic influence on the environment, and they frequently accumulate in the upper layer of the soil, where they are accessible to the roots of the plants. Except for the exclusion species, most plant species that grow on soil contaminated by heavy metals cannot avoid the absorption of these elements, but only limit their translocation. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used and the smoke from cigarette smoking presents various toxic substances, including heavy metals such as Chromium (Cr) and Manganese (Mn). The samples preparation procedures were carried out in our laboratories and submitted to the irradiation with thermal neutrons in the IPEN/CNEN-SP, in the IEA-R1 research reactor. The irradiated material was analyzed by gamma spectrometry using a high purity germanium detector (HPGe).

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  • IPEN-DOC 27084

    RODRIGUES, ANTONIO C.I. ; MADI FILHO, TUFIC ; SILVA, DAVILSON G. da . Analysis and project of the high density storage racks for spent fuel of the research reactor IEA-R1. In: INTERNATIONAL CONFERENCE ON RADIATION AND APPLICATIONS IN VARIOUS FIELDS OF RESEARCH, 6th, June 18-22, 2018, Ohrid, Macedonia. Abstract... Niš, Serbia: RAD Association, 2018. p. 143-143.

    Abstract: The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor’s pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3M) was chosen, due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Libraries were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission – CNEN and the International Atomic Energy Agency (IAEA). To calculate the keff new fuel elements (maximum possible reactivity) used in full charge of the storage rack were considered. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff <0.95). It is mandatory to use neutron absorber material.

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  • IPEN-DOC 27083

    MARTINS, E.W. ; CARDOSO, J.V.; POTIENS, M.P.A. . Determination of computed tomography quantities using a new pediatric phantom. In: INTERNATIONAL CONFERENCE ON RADIATION PROTECTION IN MEDICINE: ACHIEVING CHANGE IN PRACTICE, December 11-15, 2017, Vienna, Austria. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2018. p. 1-5.

    Abstract: A computed tomography pediatric head phantom that uses special materials to simulate the cortical and the cancellous bone was developed. This paper shows its behavior to determine the specific computed tomography radiation quantities at two calibration laboratory, the LCI-IPEN, Brazil and LMRI-IST, Portugal. The specific quantities measured were: air kerma index(Ca,100), weighted air kerma index (Cw), average volumetric air kerma index (Cvol) and the air kerma- lenght product (PKL). The reference radiation qualities used in both laboratories were the radiation qualities recommended by the norm IEC 61267 (RQT8, RQT9 e RQT10) to computed tomography dosimetry measurements. The calculated values of CW show attenuation of 11%, 13% and 10% for the qualities RQT 8, RQT 9 and RQT 10, respectively, from cortical to cancellous bone.

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  • IPEN-DOC 27082

    GERALDO, BIANCA ; VICENTE, ROBERTO ; GOES, MARCOS M. ; MARUMO, JULIO T. . Radiochemical methodology applied to determination of gamma emitting radionuclides in waste samples from IEA-R1 reactor. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 43rd, March 5-9, 2017, Phoenix, Arizona, USA. Poster... 2017.

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  • IPEN-DOC 27081

    FERREIRA, EDUARDO G.A. ; MARUMO, JULIO T. ; VICENTE, ROBERTO . Proposal of a descriptive modeling of portland cement behavior under radioactive waste repository environment. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 43rd, March 5-9, 2017, Phoenix, Arizona, USA. Poster... 2017.

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  • IPEN-DOC 27080

    GERALDO, BIANCA ; VICENTE, ROBERTO ; FERREIRA, ROBSON J. ; MADUAR, MARCELO F. ; GOES, MARCOS M. ; MARUMO, JULIO T. . Radiochemical method for characterization of the filter cartridges from the IEA-R1 reactor. In: ANNUAL WASTE MANAGEMENT CONFERENCE, March 6-10, 2016, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2016. p. 1-5.

    Abstract: The filter cartridges used in water purification system of the IEA-R1 research reactor become radioactive waste after the end of their useful life. The characterization of this waste is one step in their management, which aims at identifying and quantifying the radionuclides present, including those known as "difficult to measure" (DTM) radionuclides. Wastes from nuclear reactors contain fission and activation products and transuranic elements, only few of them emitting gamma radiation measurable by simple gamma spectrometry methods. In routine waste management activities, the concentrations of the DTM can only be estimated by indirect methods such as scaling factors. The method of the scaling factors uses empirically determined proportions between the concentrations of DTM radionuclides and that of easily measurable gamma emitters called key nuclides (KN), to calculate DTM concentrations. Determining the scaling factors for the filter cartridges is a hard task when the number of samples is large, not only because the preparation of samples is difficult but also because the number of radionuclides to analyze is large. If it can be demonstrated that DTM and KN are both distributed evenly in the filters, less samples from each filter are necessary, reducing lab work. The aim of this paper is to present the results of the assessment of homogeneity along the filter cartridges by gamma spectrometry of chemically reduced samples. Five thin slices of five filters were burnt and the ashes quantitatively dissolved and the activity concentration of the solutions determined by gamma spectrometry.

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  • IPEN-DOC 27079

    FERREIRA, EDUARDO ; VICENTE, ROBERTO ; TURRILLAS, XABIER; YOKAICHIYA, FABIANO; FRANCO, MARGARETH ; MARTINEZ, LUIS G. ; CARVALHO, ALEXANDRE; MARUMO, JULIO T. . Effects of gamma radiation on cementitious materials in repository environment. In: ANNUAL WASTE MANAGEMENT CONFERENCE, March 6-10, 2016, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2016. p. 1-10.

    Abstract: Cementitious materials are widely used in the management of radioactive waste and have to perform as required for the period of service life of the installation. In order to assess the long term durability of cement paste in a deep borehole for radioactive wastes, specimens were casted in laboratory and exposed to a gamma radiation field. The effects of the radiation in the specimens were evaluated by X-Ray Diffraction, as changes observed in the mineralogy and microstructure of the material after irradiation doses varying between 0 (without radiation) and 10 MGy. It was observed that the specimens exposed to higher doses of gamma radiation (up to 3MGy) presented differences between surface and core, when compared with the samples with no radiation or exposed to low doses. These results are important to model the behavior of cementitious materials under the conditions expected in a borehole repository and to provide data for the safety assessment of the installation.

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  • IPEN-DOC 27078

    OLIVEIRA-SILVA, T.; SUZUKI, L.C. ; LEAL, C.R.L.; KATO, I.T.; ALVARENGA, L.H.; RIBEIRO, M.S. ; PRATES, R.A.. Investigação do efeito fotodinâmico em cepas de Candida albicans pré-tratadas com glicose: estudo in vitro. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2343-2343.

    Abstract: Introdução: Candida albicans é um micro-organismo comensal presente em 80% dos indivíduos. No entanto, sua natureza oportunista pode causar severas infecções, sendo responsável por 15% dos casos de septicemia. Pode atingir indivíduos imunocompententes e imunossuprimidos, causando infecções mais graves no segundo grupo. Sua alta patogenicidade está relacionada a sua capacidade formar biofilme, uma estrutura complexa capaz de proteger C. albicans de condições ambientais desfavoráveis. O tratamento convencional com azóis não tem se mostrado eficiente devido ao aumento da expressão dos sistemas de transporte por membrana da família ABC (ATP Binding Cassette Transportes). Frente ao cenário de resistência microbiana, há necessidade de investigar novas alternativas. Uma fototerapia promissora é a terapia fotodinâmica (PDT, do inglês phodynamic therapy) que baseia-se na utilização de luz e fotossensibilizador (FS) na presença de oxigênio, formando espécies reativas de oxigênio que podem causar danos letais às células. C. albicans apresenta sensores de glicose relacionado ao seu dimorfismo (levedura-hifa), sua resposta à presença da glicose é pouco conhecida, mas acredita-se que gera um sinal intracelular que ativa os sistemas de transporte. Sendo assim, o objetivo este trabalho foi avaliar o papel da glicose ativação de uma via de entrada de fotossensibilizador para o citoplasma fúngico. Materiais e Métodos: Para o desenvolvimento do estudo, foram selecionadas as cepas ATCC 10231, YEM 13 superexpressora de poros de difusão facilitada por membrana e sua cepa selvagem YEM 12; YEM 15 superexpressora de bombas de transporte ativo e sua cepa selvagem YEM 14. C. albicans foram cultivadas aerobicamente em ágar Sabouraud e incubadas a 30°C por 24h. Os inóculos microbianos foram divididos em 4 grupos: Controle sem tratamentos; grupo irradiado sem fotossensibilizador; toxicidade do fotossensibilizador (FS) e 3 grupos PDT com irradiação de 1, 3 e 6 min. Azul de metileno na concentração final de 100μM foi utilizado como fotosensitilizador. Todos os experimentos foram realizados com e sem glicose a 50 mM. Cada experimento foi repedido pelo menos 3 vezes. Após passar pelos tratamentos, as unidades formadoras de colônia foram contadas e os dados foram submetidos à análise estatística (ANOVA) e teste de Tukey. Resultados: Os grupos irradiados sem FS não apresentaram inativação quando comparados ao grupo controle, bem como o azul de metileno não se mostrou tóxico nos parâmetros adotados no estudo. No entanto, a PDT causou morte celular proporcional a quantidade de luz entregue ao sistema. A cepa ATCC 10231 apresentou total inativação celular nos grupos com e sem glicose a partir de 3 min de irradiação. Por outro lado, as diferenças na inativação das cepas YEM 12/13 demonstram que a presença da glicose aumenta a entrada de FS e consequentemente aumenta a resposta à PDT. De maneira contrária, nas cepas YEM 14/15, a glicose promove uma espécie de proteção contra a ação da PDT. Isso pode ser relacionado à presença de bombas de transporte ativo, que com mais glicose disponível, podem bombear o FS do citoplasma. A compreensão do papel da glicose na inativação de leveduras pode elucidar mecanismos metabólicos de resposta à PDT e ser uma ferramenta importante na criação de modelos de estudos no desenvolvimento de técnicas antimicrobianas. Conclusões: A presença de glicose pode ativar a entrada de azul de metileno no citoplasma fúngico e aumentar o efeito fotodinâmico. Por outro lado, a mesma presença de glicose pode ativar bombas de efluxo na membrana da levedura e expulsar fotossensibilizador de dentro do fungo.

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  • IPEN-DOC 27077

    YOSHIKAWA, H.Y.; FERREIRA, E.S.; ZEZELL, D.M. ; LINS, E.C.C.C.; ANA, P.A.. Mudanças na fluorescência da dentina promovidas pelo laser de Er,Cr:YSGG e desafio cariogênico. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2338-2338.

    Abstract: Introdução: Diante da alta prevalência de lesões de cárie radicular, observada principalmente entre a população idosa, e a rápida progressão destas lesões [1], o que pode ocasionar a perda do elemento dental, faz-se necessária a adoção de métodos preventivos e de diagnóstico precoce efetivos, de forma que a progressão destas lesões seja monitorada e devidamente evitada. Neste aspecto, métodos ópticos baseados em lasers e LEDs tem se mostrado bastante promissores, pois possibilitam a modificação química dos tecidos duros dentais, tornando-os menos susceptíveis à perda mineral [2], assim como permitem o monitoramento das lesões incipientes de cárie de forma não invasiva, em tempo real e sem o uso de radiação ionizante [3]. Assim, o presente trabalho objetiva avaliar e monitorar os efeitos do laser de Er,Cr:YSGG na prevenção do surgimento de lesões de cárie na dentina por meio de um sistema de imageamento por fluorescência. Material e Método: 75 blocos de dentina radicular bovina foram aleatoriamente distribuídos em 5 grupos experimentais com 15 amostras cada: sem tratamento (controle negativo); com aplicação tópica de flúor fosfato acidulado - FFA (controle positivo); irradiadas com laser de Er,Cr:YSGG ( = 2,78 μm, 6 J/cm2, 20 Hz, 12,5 mJ/pulso, 0,25 W); irradiadas e seguida da aplicação de FFA e, por fim, com aplicação de FFA seguida da irradiação laser. Tais amostras foram submetidas a uuma ciclagem de pH por 8 dias, visando-se criar uma lesão incipiente de cárie. As amostras foram avaliadas por um sistema de imagens de fluorescência (SIF), baseado em uma roda mecânica com filtros ópticos banda-larga ( de corte = 450 nm), e outros com  = 500, 550 e 600 nm, uma câmera CCD científica, uma lente objetiva e um sistema de iluminação composto por LEDs ( = 405±30 nm) controlados por computador. Em todas as medidas, uma amostra de cerâmica foi mantida como amostra de referência, sendo posicionada lateralmente, em posição padronizada, à. A análise da intensidade de fluorescência de cada amostra foi obtido empregando-se o componente G do sistema RGB, empregando-se rotina desenvolvida em MatLab. O valor da intensidade de fluorescência de cada amostra foi calculado empregando-se um índice, obtido pela subtração entre o valor da amostra teste e da referência. Os dados foram analisados estatisticamente, considerando nível de significância estatística de 5%. Resultados: Quando empregados os filtros de  = 500, 550 e 600 nm, observou-se redução da intensidade de fluorescência do grupo que recebeu apenas a irradiação com laser de Er,Cr:YSGG em relação aos grupos controle positivo e negativo, sendo esta redução estatisticamente significativa (p = 0,04) quando observada com filtro de 600 nm. Observou-se aumento significativo (p = 0,03) da intensidade de fluorescência nos grupos com associação de tratamentos, sendo o grupo irradiado com posterior aplicação de FFA o que apresentou maior intensidade. Não se observou diferença estatisticamente significativa entre os grupos experimentais quando avaliados utilizando-se o filtro banda larga (p > 0,05). Conclusões: Os resultados obtidos corroboram a hipótese de que a irradiação da dentina radicular com laser de Er,Cr:YSGG pode promover mudanças na composição química da dentina, assim como na sua rugosidade por meio de micro-ablações, o que modifica a fluorescência do tecido irradiado. Ainda assim, considerando o comprimento de onda dos filtros utilizados, observa-se que a diminuição da fluorescência pode ser decorrente do aumento da perda mineral do tecido. Desta forma, de acordo com os resultados obtidos, pode-se concluir que a associação dos tratamentos (laser e FFA) parece ser a alternativa mais promissora para prevenção da desmineralização da dentina, e que o sistema de imagens de fluorescência, com os filtros empregados, trata-se de um método eficiente para avaliação da eficiência dos tratamentos propostos no surgimento das lesões de cárie radicular.

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  • IPEN-DOC 27076

    SANTOS JUNIOR, S.L.; FERREIRA, E.S.; BENETTI, C.; AMARAL, M.M. ; ZEZELL, D.M. ; GOMES, A.S.L.; ANA, P.A.. Avaliação dos efeitos do laser de Er,Cr:YSGG na dentina por tomografia por coerência óptica. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2337-2337.

    Abstract: Introdução: Mesmo com formas de tratamento bastante conhecidas, as doenças que envolvem os tecidos duros da cavidade oral ainda são bastante prevalentes, o que demonstra a necessidade de se continuar a busca por novos métodos de diagnóstico e prevenção. A literatura mostra possibilidades promissoras relacionadas à utilização dos lasers de alta intensidade para prevenção da cárie [1], tendo em vista o aquecimento promovido pelos mesmos [2]. Por outro lado, o diagnóstico de lesões de cárie em estágios iniciais possibilita a adoção de procedimentos para paralisar as mesmas. Os métodos baseados em biofotônica podem auxiliar neste processo, considerando os bons resultados reportados tanto para prevenção das lesões, empregando-se lasers em alta intensidade, quanto para diagnóstico óptico, empregando-se radiação não ionizante. A técnica de tomografia por coerência óptica (OCT) fornece imagens transversais de estruturas através de imageamento óptico, não é invasiva e não utiliza radiação ionizante[3]. Neste sentido, este estudo objetiva avaliar o efeito do laser de Er,Cr:YSGG para prevenção do surgimento de lesões de cárie radicular, assim como avaliar o potencial da OCT no monitoramento da progressão desta lesões. Material e Método: Foi conduzido um estudo in vitro cego com 75 blocos de dentina radicular de 2 x 2 x 4 mm, os quais foram aleatoriamente distribuídos em 5 grupos experimentais (n=15): G1 – sem tratamento, G2 – grupo tratado com flúor fostato acidulado (FFA – 1,23% F, pH 3,3 – 3,9, por 4 minutos – controle positivo), G3 – grupo irradiado com laser de Er,Cr:YSGG (l = 2,78 μm, 20 Hz, 6 J/cm2, sem refrigeração), G4 – grupo irradiado seguido da aplicação de FFA, G5 – grupo tratado com FFA seguido da irradiação laser. As amostras foram submetidas a um desafio cariogênico in vitro por meio de ciclagem de pH com duração de 8 dias. Após, as amostras foram avaliadas por tomografia por coerência óptica (OCT Callisto, l = 930 nm, Thorlabs Inc., Estados Unidos), em que foram realizados 5 escaneamentos equidistantes por amostra ao longo eixo das lesões formadas. Depois da aquisição das imagens, foi calculado o coeficiente de atenuação óptica a partir do decaimento exponencial da intensidade da luz retroespalhada de todos os grupos, utilizando-se rotina desenvolvida em software MatLab. A análise estatística foi executada empregando-se o teste estatístico de Kruskal-Wallis e Student-Newman-Keuls, considerando-se o nível de significância estatística de 5%. Resultados: Nenhum dos tratamentos pospostos apresentou desgaste da superfície após desafio cariogênico. Observouse que o grupo irradiado apresentou coeficiente de atenuação óptica (13,6 ± 1,57 μm-1) significativamente maior (p < 0,05) que os demais grupos experimentais. Os demais grupos apresentaram os seguintes valores de coeficiente de atenuação óptica: G1: 12,72 ± 0,98 μm-1 12,65 ± 0,92 μm-1 12,6 ± 1,4 μm-1 12,76 ± 1,15 μm-1. Desta forma, os outros grupos, quando comparados entre si, não diferiram estatisticamente. Conclusões: A irradiação da dentina com laser de Er,Cr:YSGG isoladamente possibilitou a redução da desmineralização, evidenciada pelo aumento do coeficiente de atenuação óptica. Ainda assim, a tomografia por coerência óptica apresenta-se como uma técnica promissora para avaliação dos efeitos da irradiação laser sobre as lesões incipientes de cárie.

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  • IPEN-DOC 27075

    SANTOS, G.L.; SANTUCCI, G.; OLIVEIRA-SILVA, T.; PRATES, R.A.; RIBEIRO, M.S. ; KATO, I.T.. Alteração da susceptibilidade de C. albicans resistente ao fluconazol após terapia fotodinâmica. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2336-2336.

    Abstract: Introdução: As doenças infecciosas causadas por fungos ainda representam um grande desafio para os profissionais de saúde e a comunidade científica, especialmente as infecções causadas por micro-organismos resistentes aos fármacos antifúngicos convencionais. Novas alternativas de tratamento foram estudadas, entre elas a terapia fotodinâmica (PDT) que surgiu como uma promissora modalidade terapêutica por causar a morte de micro-organismos a partir da associação de um fotossensibilizador e luz. Recentemente observamos que a PDT realizada em condições subletais aumenta a suscetibilidade do fungo Candida albicans ao fluconazol [1]. Dando continuidade a este estudo iniciamos a investigação em C. albicans que apresentam diferentes mecanismos de resistência aos antifúngicos. Assim, o presente trabalho teve o objetivo de avaliar o efeito antimicrobiano da associação de PDT e fluconazol em C. albicans que apresenta um sistema de efluxo responsável pela resistência ao antifúngico. Materiais e Métodos: Para a realização deste trabalho foi utilizado C. albicans YEM 13, uma cepa com expressão exacerbada de bomba de efluxo da família MFS (Major Facilitator Superfamily). As células foram submetidas a PDT com azul de metileno na concentração final de 50 μM e irradiadas com parâmetros subletais (=660 nm, 75 mW/cm2, 4 min)[1]. Para investigar a atividade antimicrobiana do fluconazol foram determinados os valores de concentração mínima inibitória (CMI) do crescimento celular. A CMI foi determinada pelo método de microdiluição em caldo de acordo com as normas estabelecidas pelo Comitê Europeu de Teste à Susceptibilidade Antimicrobiana (EUCAST)[2]. A solução de fluconazol (Sigma Aldrich, São Paulo, Brasil) foi preparada, considerando a potência do fármaco de 98% e a faixa de concentrações testadas foi de 0,125-64 μg/mL. Os valores de CMI foram determinados por meio da leitura da absorção em 530 nm, em espectrofotômetro (SpectraMax M4, Molecular Devices, EUA). Para cada grupo foi determinada a menor concentração da droga que promoveu a inibição ≥ 50% do crescimento em comparação ao controle livre de drogas. Foram avaliadas células C. albicans YEM 13 sem tratamento e previamente submetidas a PDT subletal. Foi utilizado como controle a cepa de C. albicans ATCC 90028 que não apresenta resistência ao fluconazol. Resultados: C. albicans ATCC 90028 apresentou valor de CMI de 0,5 μg/mL, dado compatível com os descritos na literatura. As amostras de célula YEM 13 que não foram submetidas à PDT apresentaram o valor de CMI de 64 μg/mL, que também coincide com o valor descrito na literatura [3]. Estes dados demonstram que a cepa YEM 13 apresenta um valor de CMI 128 vezes superior ao de uma cepa suscetível ao fluconazol (ATCC 90028). Confirmando nossa hipótese, o fluconazol foi mais ativo em C. albicans submetida previamente à PDT subletal. Dentro da faixa de 0,125-64 μg/mL, houve maior inibição do crescimento celular quando previamente submetido à PDT, resultando na redução do valor de CMI de 64 μg/mL para 32 μg/mL. Conclusões: Foi possível demonstrar que a PDT pode aumentar a susceptibilidade ao fluconazol em cepa de C. albicans que apresentam bombas de efluxo da família MFS. Estes resultados preliminares sugerem que a associação terapêutica entre a PDT e o fluconazol pode ser uma importante alternativa no tratamento de infecções por cepas de C. albicans que apresentam resistência a este antifúngico. Vale ressaltar que neste trabalho foram utilizadas condições subletais e resultados ainda mais promissores podem ser obtidos com a otimização dos parâmetros de irradiação.

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  • IPEN-DOC 27074

    LEAL, C.R.L.; SILVA, T.O.; ALVARENGA, L.H.; BUSSADORI, S.K.; RIBEIRO, M.S. ; KATO, I.T.; PRATES, R.A.. Aplicação da terapia fotodinâmica com uso do LED e azul de metileno em Streptococcus mutans: estudo in vitro. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2333-2333.

    Abstract: Introdução: Streptococcus mutans é considerado como colonizador primário para o desenvolvimento da cárie dentária. As propriedades cariogênicas de S. mutans são reguladas por diversos genes, envolvidos em vias metabólicas essenciais: adesão microbiana, formação do biofilme, síntese de polissacarídeo extracelular, captação de carboidratos e tolerância ao ácido. S. mutans normalmente habita um biofilme complexo. A bactéria produz uma grande quantidade de exopolissacarídeos, principalmente na presença da glicose facilitando o processo de adesão e ativando bombas de transporte que podem facilitar a entrada aumentando o acúmulo do fotossensibilizador dentro da célula [1]. A terapia fotodinâmica envolve a utilização de um fotossensibilizador (FS), que é absorvido por células específicas seguida de irradiação com luz visível, resultando na morte celular [2]. Este trabalho tem o objetivo de investigar a morte celular do Streptococcus mutans após a terapia fotodinâmica com azul de metileno e LED com e sem glicose. Material e Metodologia: Neste trabalho o Streptococcus mutans foi cultivado em microaerofilia em ágar infusão de cérebro e coração (BHI) incubado a 37o por 48 horas. Os inóculos foram preparados com a coleta de colônias puras que foram suspensas em solução salina fosfatada tamponada (PBS) com e sem 50 mM de glicose. O fotossensibilizador azul de metileno foi adicionado à suspensão proporcionando a concentração final de 100 μM. Todos os experimentos foram realizados com 6 grupos diferentes (grupo controle; grupo irradiado com LED sem FS; grupo FS sem irradiação; e grupos PDT). Os tempos de irradiação do grupo PDT foram de 30,, 60 e 120 segundos. Os resultados foram submetidos à análise estatística com teste de variância one-way (ANOVA). A comparação entre as médias foi realizada pelo teste de Tukey e a significância foi ajustada em 5%. Resultados: A irradiação somente com luz não apresentou morte celular, assim como o fotossensibilizador não apresentou toxicidade no escuro, pois, o grupo controle não apresentou diferenças significativas quando comparado com os grupos luz e fotossensibilizador em todos os experimentos com e sem glicose. Em contrapartida nos experimentos sem glicose a PDT provocou morte celular proporcional a quantidade de luz empregada. Quanto maior a exposição radiante, maior foi a inativação do S. mutans. Após 2 min. de irradiação observamos redução de 100% das bactérias, apresentando uma redução de 7 ordens de grandeza em relação ao grupo controle. Nos experimentos com glicose não foi observada morte celular mesmo aumentando a exposição radiante após 2 min. de irradiação. Conclusão: Podemos concluir que a PDT é uma solução viável para inativação de S. mutans em suspensão, e que a presença da glicose reduz drasticamente o efeito da PDT..

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  • IPEN-DOC 27073

    SOUZA, E.R.L.B. de; ALVARENGA, L.H.; LEAL, C.R.L.; LEITE, C.G.; PEREIRA, T.R.; VIEIRA, D.C.; PRETTO, L. de ; FREITAS, A.Z. de ; FERNANDES, A.U.; PRATES, R.A.. Terapia fotodinâmica antimicrobiana combinada ao tratamento periodontal em ratos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2332-2332.

    Abstract: Introdução: A Terapia Fotodinâmica antimicrobiana (aPDT) vem sendo utilizada como adjuvante ao tratamento da periodontite. Ela combina um fotossensibilizador (FS) e fonte de luz para produzir espécies reativas de oxigênio e matar células microbianas [1]. A PpNetNI é um derivado da protoporfirina, e tem um sítio de ligação química no biofilme e grande afinidade às células microbianas. Este estudo tem como objetivo investigar os efeitos da aPDT como adjuvante ao tratamento da periodontite. Materiais e Métodos: Este estudo (aprovado pelo Comitê de Ética da UNINOVE AN0029/2015) incluiu 18 ratos machos Wistar saudáveis (Rattus norvegicus). A periodontite foi induzida pela inserção de uma ligadura de algodão em posição subgengival no primeiro molar inferior. O primeiro molar inferior contralateral não recebeu a ligadura ou nenhum tipo de tratamento, e foi utilizado como controle. Após 7 dias, a ligadura foi removida e todos animais receberam raspagem e alisamento radicular (RAR) [2]. Os grupos (n=3) foram então divididos em: 1) grupo RAR (receberá RAR e irrigação com PpNetNI, 10 μM, sem irradiação) e 2) grupo PDT (irrigado com PpNetNI 10 μM seguido de irradiação com LED durante 90 s). Para irradiação foi utilizado um LED emitindo comprimento de onda de 630 nm com potência radiante de 400 mW (irradiância - 200 mW/cm2; exposição radiante - 18 J/cm2). As avaliações foram realizadas 24 h, 48 h e 7 dias após a intervenção e para isto, 3 animais de cada grupo foram eutanasiados em cada momento experimental. A área de perda óssea na região vestibular do primeiro molar inferior foi avaliada por Tomografia de Coerência Óptica (OCT, THORLABS LTD., Ely, UK). Os dados foram submetidos à análise estatística (teste Mann-Whitney, p˂0.05). Até o momento foram avaliados 6 animais, que foram tratados conforme descrito e eutanasiados 7 dias após o término do tratamento. Resultados: Dentre os animais que foram eutanasiados 7 dias após o término do tratamento, os animais do grupo PDT mostraram um ganho ósseo de aproximadamente 30% quando comparados ao grupo RAR. A OCT foi capaz de detectar a perda óssea nas amostras e foi um método não destrutivo para este modelo experimental. Conclusões: Com os dados obtidos até o momento e com os parâmetros utilizados neste estudo podemos concluir que a aPDT foi uma alternativa eficaz em garantir a saúde periodontal e foi capaz de regenerar os tecidos de suporte periodontal.

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  • IPEN-DOC 27072

    AMARAL, M.M. ; TEIXEIRA, L.R.C. ; CARVALHO, M.T.; GOMES, A.S.L.; ZEZELL, D.M. . Avaliação da espessura da epiderme em hemangioma por optical coherence tomography. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2331-2331.

    Abstract: Introdução: Os Hemangiomas são lesões vasculares que comumente encontradas na região da cabeça e pescoço, atingindo cerca de 10% das crianças ao redor do mundo [1]. O diagnóstico precoce pode levar ao tratamento das lesões e redução de suas consequências estéticas e psicológicas causadas ao paciente. A biopsia excisional é o padrão ouro para diagnostico a nível celular, porém é uma técnica invasiva e que pode causar efeitos colaterais. As alternativas não invasivas disponíveis são a tomografia computadorizada (CT), a imagem por ressonância magnética (MRI) e o ecografia por ultrassom (US) [1, 2]. Tanto o CT quanto o MRI apresentam um custo proibitivo para aplicações clínicas de rotina. Já o US está presente em hospitais e possui custo mais acessível com aplicações no diagnóstico vascular. A imagens US atinge camadas profundas com resolução e alguns milímetros no do tecido biológico, não atendendo aos hemangiomas que aparecem nas camadas mais superficiais da pele. Uma possível alternativa é a técnica Optical Coherence Tomography (OCT) que produz imagens em seção transversal com resolução micrométrica do tecido biológico utilizando luz. Ela encontra aplicações na dermatologia [3] e pode ser usado para caracterização funcional, óptica ou morfológica de tecido biológico. O objetivo deste trabalho foi avaliar as diferenças de espessura da epiderme em regiões de lesão vascularizada e normal utilizando a técnica OCT. Materiais e Métodos: As imagens OCT foram adquiridas utilizando-se um sistema OCT swept source com resolução axial de 9 μm e lateral de 18 μm. As imagens possuem 512x1024 pixel (axial x lateral) e foram adquiridas a uma taxa de 25 quadros / s. Este estudo foi aprovado pelo Comitê de Ética do IMIP (protocolo no. 728.993). Neste estudo fo ram utilizadas imagens da mão de um paciente nas regiões de hemangioma e pele sadia, possibilitando a identificação de suas diferenças. Foi implementado um algoritmo em ambiente Matlab para determinar a espessura da epiderme em todas as 541 imagens de lesão vascularizada e as 50 de pele normal. Resultados: Através da medição automatizada da espessura da epiderme na região de lesão e sadia (figura 1) foi possível observar a distribuição de profundidade em cada uma destas regiões. A região de lesão possui uma distribuição de profundidade mais estreita e com espessura menor que a de pele normal. Já a região de pele normal apresenta uma distribuição mais larga, porém com dois valores de maior probabilidade, isso se deve tanto a presença de glândulas mais visíveis na pele sadia quanto a uma maior presença de papilas dérmicas na junção derme-epiderme. Conclusões: A medição da espessura da epiderme mostrou-se válida como um possível marcador da presença de hemangioma. O uso desta abordagem poderia ser complementar a outros marcadores possíveis de serem extraídos do sinal OCT. A ampliação do painel de estudo e comparação com outras técnicas padrão ouro deverá ser realizada em futuros estudos.

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  • IPEN-DOC 27071

    FERREIRA, E.S.; BENETTI, C.; ZEZELL, D.M. ; KATO, I.T.; ANA, P.A.. Efeitos da irradiação com laser de Er,Cr:YSGG na temperatura pulpar e superficial da dentina radicular. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1937-1940.

    Abstract: Tendo em vista o envelhecimento da população e a permanência dos dentes na cavidade oral, observou-se um aumento da incidência da cárie radicular em idosos. Os lasers de érbio podem ser usados para prevenção de cárie; contudo, ainda não são estabelecidos parâmetros de irradiação que sejam seguros para os tecidos pulpares e periodontais e que sejam efetivos para ocasionar alterações químicas na superfície da dentina. Este estudo avaliou os efeitos da irradiação da dentina radicular com laserde Er,Cr:YSGG na temperatura pulpar e superficial da dentina, buscando-se determinar parâmetros de irradiação seguros e efetivos para futura aplicação clínica. Para tal, foi realizado um estudo in vitro randomizado com duas fases experimentais. Na primeira fase, 30 blocos de dentina radicular bovina foram empregados para avaliar a temperatura superficial ocasionada por um único pulso laser empregando-se termografia no infravermelho, enquanto que, na segunda fase experimental, 30 dentes incisivos inferiores humanos foram empregados para avaliação da temperatura pulpar durante as irradiações por 10 segundos empregando-se termopares de resposta rápida. As irradiações foram efetuadas com laser de Er,Cr:YSGG,  = 2,78 μm, 20 Hz, sem refrigeração, com potências médias de 0,1 W, 0,25 W e 0,5 W, o que resultou em densidades de energia de 2,4 J/cm2, 6 J/cm2 e 12 J/cm2, respectivamente. Observou-se variações de temperatura superficial de 61  26 oC, 75  34 oC e 172  36 oC para os grupos irradiados com potência média de 0,1 W, 0,25 W e 0,5 W, respectivamente. Foram registradas elevações médias de temperatura pulpar de 0,81 ± 0,4 oC, 1,76 ± 0,7 oC e 2,95 ± 1,33 oC, para os grupos irradiados com potência média de 0,1 W, 0,25 W e 0,50 W, respectivamente. Concluiu-se que o laser de Er,Cr:YSGG promove elevações de temperatura superficiais que indicam a ocorrência de transformações químicas na superfície da dentina radicular; contudo, dos parâmetros testados, se considerarmos as elevações de temperatura pulpar, a potência média de 0,25 W é a que se apresenta mais promissora para futuro uso para prevenção da cárie radicular.

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  • IPEN-DOC 27070

    GONÇALVES, KARINA de O.; SILVA, MONICA N. da; COURROL, LILIA C. . Síntese de nanopartículas de ouro funcionalizadas com ácido aminolevulínico e laser de pulsos ultracurtos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1913-1916.

    Abstract: As nanopartículas de ouro apresentam inúmeras aplicações na medicina. As diferenças de tamanho, forma e propriedades de superfície, fazem com que suas aplicações se tornem versáteis, como por exemplo, a terapia fototérmica e o rastreamento de tumores (biomarcadores). Foi recentemente demonstrado na literatura que a incorporação de nanopartículas de ouro na estrutura do ácido 5-aminolevulínco (5-ALA) melhora as propriedades fotodinâmicas do fármaco. O estudo com laser ocorreu visando à possibilidade de modificação no formato das nanopartículas, de esféricas para outras formas, entre elas bastões e prismas que resultam em bandas de plasmons de comprimentos de onda maiores, uma vez que nanopartículas com formato mais cilíndrico apresentam uma janela na região da janela óptica do tecido biológico e desta forma a luz aplicada em PDT teria maior profundidade de penetração no tecido. Assim propomos neste estudo, sintetizar nanopartículas de ouro com 5-ALA, para realizar o diagnóstico e a terapia (Teranóstica) de doenças com crescimento não controlável, de uma forma mais simples, menos invasiva e mais barata.

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  • IPEN-DOC 27069

    PROVASI, C.; CASSIMIRO-SILVA, P.F.; ANA, P.A. da; ZEZELL, D.M. ; GOMES, A.S.L.; LINS, E.C.. Estudo da espectroscopia de reflexão com radiações visíveis e infravermelhas para discriminação de tecidos pulpares humanos sadios e patológicos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1909-1912.

    Abstract: A polpa dental é o tecido mais interno do dente. Sua principal função é garantir a dentinogênese e a sensibilidade dental, e por essa razão a informação clínica sobre a saúde da polpa é relevante. Polpas diagnosticadas como não-vitais são encaminhadas para um tratamento endodôntico agressivo, baseado na remoção de todo tecido degradado. Por esse motivo, deve-se haver um esforço em minimizar o número de falsos diagnósticos clínicos da vitalidade pulpar, na intenção de preservar a integridade do paciente. Esse estudo propõe a espectroscopia no visível e no infravermelho como método de melhorar a precisão no diagnóstico do status pulpar. Ele é baseado em confrontar a reflexão óptica dos tecidos no espectro do visível (VIS) e do infravermelho próximo (NIR) (350nm a 1.700nm) no intuito de discriminar polpas humanas vitais de outras polpas sintomáticas de pulpite. A Análise dos Componentes Principais (PCA) sobre os espectros de reflexão ainda propôs modelos matemáticos de diferenciação dos grupos. Os resultados revelaram que a reflexão óptica pode discriminar o status da vitalidade de polpas humanas vivas; e a análise estatística da PCA revelou precisão de acerto de 100% para radiações NIR e 95% para radiações VIS.

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  • IPEN-DOC 27068

    PEREIRA, D.L. ; FREITAS, A.Z. ; ZEZELL, D.M. ; ANA, P.A.. Uso da tomografia por coerência óptica no monitoramento de lesões de erosão e abrasão em dentina. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1861-1864.

    Abstract: O objetivo deste trabalho foi avaliar o potencial da tomografia por coerência óptica (OCT) para o diagnóstico precoce e monitoramento de lesões de erosão e abrasão em dentina. Para isso, foi realizado um estudo in vitro com 192 blocos de dentina radicular bovina de 8 mm2, distribuídos aleatoriamente em quatro grupos experimentais (n = 48): G1- sem tratamento; G2- tratamento com flúor fosfato acidulado (FFA, 1,23% F-, pH = 3,3–3,9); G3- irradiação com laser de Nd:YAG (1064nm, 0,6W, 10Hz, 84,9J/cm2); G4- aplicação de FFA, seguida de irradiação com laser de Nd:YAG. Após os tratamentos, as amostras foram submetidas a um desafio de erosão e abrasão por escovação (Sprite Zero, pH=2,6, 90s, 4x/dia) e remineralização (saliva artificial, pH=7) durante 15 dias, sendo avaliadas por OCT em 5 momentos distintos: antes e após os tratamentos, e após 5, 10 e 15 dias de desafio. Foi possível observar o desenvolvimento e evolução das lesões de erosão/abrasão e também foi possível relacionar a desmineralização do tecido decorrente do processo de erosão/abrasão com o coeficiente de atenuação óptica.

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  • IPEN-DOC 27067

    OLIVEIRA, L.Z.; WATANABE, T.E.; GOUVEIA, D.S. ; BRESSIANI, A.H.A. ; RIBEIRO, C.. Estudo da síntese para obtenção de hidroxiapatita em meio de colágeno. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 251-254.

    Abstract: A obtenção da hidroxiapatita - HA nanoestruturada pode exigir modificações nas técnicas convencionais de síntese a fim de mimetizar estruturalmente as bioapatitas. A técnica de neutralização já vem sendo explorada em função de sua simplicidade e versatilidade, mas sua reprodutibilidade nem sempre é garantida, sugerindo a formação de fases intermediárias precursoras da HA, e algumas vezes outras fases, como o óxido de cálcio, além do alto estado de aglomeração de suas partículas. Com intuito de obter pós nanométricos de natureza dispersa e garantir a estabilidade da HA foi adicionado colágeno hidrolisado (4% em massa) ao meio de precipitação, variável ainda pouco explorada em processos de síntese. Os pós obtidos foram caracterizados por DRX, sendo observada a presença da fase pura e aumento da cristalinidade após calcinação a 800oC/3h, ainda verificou-se maior perda de massa para esta HA quando comparada a técnica clássica de precipitação (sem colágeno). Os resultados obtidos indicaram a viabilidade da metodologia para obtenção da HA, confirmando a natureza nanométrica dos pós e estabilidade da fase, logo após a síntese, e também após calcinação. A HA sintetizada apresentou cerca de 95% de densificação, microestrutura que pôde ser comprovada por MEV, além de manter sua estrutura cristalina, sem a formação de fase secundária, conforme observado por DRX, após sinterização a 1100oC/1h. A metodologia de síntese, em meio de colágeno, proporcionou a obtenção de pós de HA nanométrica de adequada sinterabilidade e estabilidade, podendo gerar microestruturas densas, mantendo fase única.

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  • IPEN-DOC 27066

    MATOS, BRUNO R. ; MORAES, LETICIA P.R. ; SANTIAGO, ELISABETE I. ; FONSECA, FABIO C. . Synthesis and proton conductivity of Nafion with addition of CsHSO4. In: INTERNATIONAL CONFERENCE ON ADVANCED ENERGY MATERIALS, 1st; INTERNATIONAL CONFERENCE ON ADVANCED NANOMATERIALS, 8th; INTERNATIONAL CONFERENCE ON HYDROGEN ENERGY, 2nd, September 12-14, 2016, Guildford, England. Abstract... 2016. p. 53-53.

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  • IPEN-DOC 27065

    COSTA, PRISCILA ; RAELE, MARCUS P. ; YORIYAZ, HELIO ; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. . Modelling a prototype of thermal neutron detector using a thin boron film and a photodiode. In: ENCONTRO DE FÍSICA; ENCONTRO NACIONAL DE FÍSICA DA MATÉRIA CONDENSADA, 39.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 39.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 37.; ENCONTRO BRASILEIRO DE FÍSICA DOS PLASMAS, 13.; ENCONTRO DE PESQUISA EM ENSINO DE FÍSICA, 16., 3-7 de setembro, 2016, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2016.

    Abstract: Neutron detection is an important task especially for worker protection in nuclear installations. For that purpose, it is desired to have portable and compact detectors, an aim which can be achieved using semiconductor detectors. In this work the Monte Carlo modelling of a neutron detector based on a thin boron film and photodiode is presented. The simulation was carried out using the MCNP6 code, in order to evaluate the detection efficiency for the alpha particles emitted in the boron neutron capture reaction. Two different setup subsets were modelled, taking into account the fact that the film could be deposited either in direct contact to the photodiode surface, or in indirect contact, where the film was deposited in a substrate (glass). In direct contact the thin film thickness ranged from 0 to 5 μm. For the indirect contact the thicknesses of the substrate and air region were varied. For both cases, the model was also prepared to consider the situation in which the film was sandwiched between two photodiodes in order to increase alpha particle detection efficiency. The results show that the thickness of the substrate, of 150 μm or 1000 μm, has a small influence on the alpha particle flux on the photodiode surface. The increase of the air region causes a decrease of 57 % in the flux of alpha particles in the photodiode. These different setups allowed determining the thickness values of thin boron film that delivers a higher alpha particle flux, which will lead to an optimum detection efficiency.

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  • IPEN-DOC 27061

    TERADA, M.; QUEIROZ, F.M.; COSTENARO, H.; OLIVIER, M.G.; COSTA, I. ; MELO, H.G. de. Effect of cerium (III) on the corrosion protection properties of the film formed on the AA2524-T3 alloy by hydrothermal treatments. In: EUROPEAN CORROSION CONGRESS, September 11-15, 2016, Montpellier, France. Proceedings... Frankfurt, Germany: European Federation of Corrosion, 2016. p. 1-9.

    Abstract: Many industries use chromium-based anodizing processes with a subsequent sealing post-treatment containing hexavalent chromium ions to protect Al alloys. However, this method of protection causes large environmental and health related problems. This has encouraged the search for new surface treatments for metals with the requirements of effective protection against corrosion and generation of non-toxic residues to the environment. Recent studies are pointing towards chromium free anodizing processes, specifically the tartaric-sulfuric acid (TSA) one, as a viable alternative. Besides, sealing treatments of the Al anodic layer in chromate solutions are another source of toxic residues and their replacement for environmentally friendly alternatives are also of great interest. Surface treatments with cerium ions are being largely studied for the corrosion protection of Al alloys due to their good anticorrosion properties associated to the lack of toxic residues generated. In this investigation, a hydrothermal treatment in aqueous solution with cerium ions has been proposed as a post-treatment for TSA anodizing, and its effects on the AA2524-T3 alloy corrosion resistance investigated. This alloy presents a chemical composition similar to the AA2024 but with lower and more controlled amounts of alloying elements. The sealing treatment was carried out by immersion in aqueous solutions with cerium ions at the boiling temperature. The effect of Ce on the characteristics of the surface film formed, such as morphology and corrosion resistance, was investigated by SEM and electrochemical impedance spectroscopy. The results were compared to those of sealing in boiling water. The results showed that the sealing treatment in solution with Ce(III) ions presented a less stable behavior than the sealing with only boiling water. However, the results of the EIS experiments showed recovery of the protective properties of the system, indicating that some self-healing properties must be imparted to the system.

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  • IPEN-DOC 27051

    LOPES, HENRIQUE D.; NUNES, EDUARDO; COLOSIO, MARCO; ROSSI, JESUALDO . PM conversion study for a transmission component: scuffing wear ranking of nitrided Astaloy CrA and reference CQT 16MnCrS5 Rollers. In: WORLD PM2016 CONGRESS AND EXHIBITION, October 9-13, 2016, Hamburg, Germany. Proceedings... Chantilly, France: European Powder Metallurgy Association, 2016. p. 1-7.

    Abstract: Net shape manufacturing advantages and its cost effectiveness is well known for sintered structural parts for many automotive applications. Combined with cost effective material solutions, plus smart secondary processes, and finally leading to higher product performance, PM technology can add even more value to customer processes and end user applications. This paper describes the conversion study of a manual transmission component from wrought to pm steel, while presenting the results of comparing the wear performance when subjected to moderate forces and high sliding velocities. The authors analyzed the behavior of PM based Cr plus nitriding (gas or plasma) specimens in comparison with a wrought steel plus carburizing. The component lifetime and reliability was evaluated according to the IRG-diagram. The final conclusion is that the PM material has better wear performance than the current wrought steel component.

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  • IPEN-DOC 27048

    CARDOZO, NELSON X. ; OMI, NELSON M. ; AMBIEL, JOSE J. ; FEHER, ANSELMO ; NAPOLITANO, CELIA M. ; SOMESSARI, SAMIR L. ; CALVO, WILSON A.P. . Development of an irradiation system for radioisotope production applied to industrial process tomography. In: WORLD CONGRESS ON INDUSTRIAL PROCESS TOMOGRAPHY, 8th, September 26-29, 2016, Foz do Iguaçu, PR. Proceedings... International Society for Industrial Process Tomography, 2016.

    Abstract: Among the various applications of radioisotopes, the use of radiotracers is considered the most important in diagnosing operation and troubleshooting of industrial process plants in chemical and petrochemical companies. The radiotracers are used in analytical procedures to obtain qualitative and quantitative data systems, in physical and physicochemical studies transfers. In the production of gaseous radioisotopes used as tracers in industrial process measurements, argon-41 (41Ar) and krypton-79 (79Kr) have low reactivity with other chemical elements. 41Ar is a transmitter range with high-energy (1.29MeV) and a high percentage of this energy transformation (99.1%), resulting in relatively small quantities required in relation to the other, for an efficient detection, even in large thicknesses components. Nowadays, the production of gaseous radioisotopes in nuclear research reactors is performed in small quantities (batches), through quartz ampoules containing natural gas 40Ar or 78Kr. In this sense, the aim of this study is to develop an irradiation system for gaseous radioisotope production in continuous scale, applied in industrial applications of emission tomography and flow measurement. The irradiation system may produce 41Ar with activity of 7.4x1011Bq (20Ci) per irradiation cycle, through the Reactor IEA-R1 with 4.5MW and average thermal neutron flux of 4.71x1013 ncm-2s-1 to meet an existing demand in NDT and inspections companies, and even needed by the Radiation Technology Centre, at IPEN/CNEN-SP. The irradiation system consists of an aluminium irradiation capsule, transfer lines, needle valves, stripy connections, quick connectors, manometer, vacuum system, dewar, lead shielding, storage and transport cylinders, among other components. The irradiation system was approved in the leakage and stability tests (bubble test, pressurization, evacuation and with leak detector equipment SPECTRON 600 T). In the experimental production, alanine dosimeters were distributed into various components of the irradiation system, obtaining 1.07x1011Bq (2.9Ci) of 41Ar. In addition, exposure rates were determined in the lead shielding wall, in which the liquefied radioactive gas was concentrated, and in the storage and transport cylinders after 41Ar was transferred, by the portable radiation meter Teletector ® Probe 6150 AD-t/H.

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  • IPEN-DOC 27044

    KIM, HAE Y.; HARAGUCHI, M.I.; CALVO, W.A.P. . Comparison of industrial tomography algorithms for gamma scanning 2-D reconstruction. In: WORLD CONGRESS ON INDUSTRIAL PROCESS TOMOGRAPHY, 8th, September 26-29, 2016, Foz do Iguaçu, PR. Proceedings... International Society for Industrial Process Tomography, 2016. p. 1-7.

    Abstract: In this paper, we compare different industrial tomography algorithms to present the result of gamma scanning as a two-dimensional image of density distribution. In two-dimensional gamma scanning, an unconventional irradiation geometry is used and consequently many classic image reconstruction algorithms cannot be used. We tested two iterative reconstruction methods: ART (Algebraic Reconstruction Technique) and MART (Multiplicative Algebraic Reconstruction Technique). The iteration steps of both methods were intercalated with various filters: mean filter, median filter, anisotropic diffusion and total variation. The use of these filters greatly improves the quality of reconstruction. We report the obtained results.

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  • IPEN-DOC 27049

    SANTOS, RENATA S. da S.; SILVA, MARCOS P. de A.; HOELZEMANN, JUDITH J.; SILVA, CLAUDIO M.S. e; LANDULFO, EDUARDO ; LOPES, FABIO J. da S. . Study of cirrus clouds physical properties using the Lidar-DUSTER system and radiosounding data at Natal/RN- Brazil. In: ALBUQUERQUE, TACIANA T.A. (Ed.); ANDRADE, MARIA DE F. (Ed.); SANTOS, JANE M. (Ed.) AIR POLLUTION CONFERENCE BRAZIL; COMMUNITY MODELING AND ANALYSIS SYSTEM SOUTH AMERICA, 4th, July 22-24, 2019, Belo Horizonte, MG. Proceedings... Belo Horizonte, MG: SEAD, Treinamentos e Coaching, 2019. p. 355-360.

    Abstract: Cirrus clouds are classified as the highest clouds in the atmosphere occurring generally from 7 to 18 km, depending on the global region of appearance, and have necessarily ice crystals in their composition. They still have an uncertain influence role in climate, therefore are seen as important atmospheric elements to be studied. Lidar systems (LIght Detecting and Ranging) have shown efficiency in the collection of cirrus characteristics which can help in its better parameterization in climatic and atmospheric models. In this work a collection of physical characteristics of cirrus was carried out, for January and February of 2017 and 2018, at Natal’s atmosphere using Lidar DUSTER’s data (5.84 S 35.20 W), a partnership UFRN/IPEN-SP. Morphological patterns of that clouds have been observed according to its heights as well as variations. Clouds with thinner depths and tenuous are observed at the top regions of troposphere, around 16.0 km. Otherwise, clouds with bigger vertical extensions are found around 12.0 km. The height of occurrence of cirrus in Natal, for the considered period vary from a minimum height of 7.0 km to a maximum of 16.0 km. Cirrus clouds most frequently occurred at a medium height of 12.0 km, considering both years. Those clouds had a considerable representativeness over the city atmosphere corresponding to 67% of total Lidar measured days. Besides the Lidar system was also used data from radiosounding technique. The behavior of the meteorological variables such as relative humidity was analyzed for the regions in which were found cirrus by the Lidar DUSTER. Within the region limits was verified a significant increase of relative humidity values. This behavior is not observed in lower regions where there is not any clouds presence as well in a day without cirrus appearance. In addition, future analyzes of the potential equivalent temperature profile will be studied in order to verify the effect of the cirrus clouds occurring in the temperature and humidity profile in a combined manner. Also, is expected to evaluate the possible impacts of cold air intrusion of the stratosphere in layers of cirrus clouds. In conclusion, Lidar DUSTER data demonstrates to be efficient in the identification of cirrus clouds over Natal’s atmosphere contributing to a better comprehension of its behavior and role in the region of study.

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  • IPEN-DOC 27047

    RAE, CRISTINA T.S.; HOELZEMANN, JUDITH J.; OLIVEIRA, DANIEL C.F.S.; SILVA, MARCOS P.A.; LOPES, FABIO J.S. ; LANDULFO, EDUARDO . Atmospheric aerosol behavior study in Natal city through LIDAR backscatter profiles and random errors propagation analysis by Monte Carlo method. In: ALBUQUERQUE, TACIANA T.A. (Ed.); ANDRADE, MARIA DE F. (Ed.); SANTOS, JANE M. (Ed.) AIR POLLUTION CONFERENCE BRAZIL; COMMUNITY MODELING AND ANALYSIS SYSTEM SOUTH AMERICA, 4th, July 22-24, 2019, Belo Horizonte, MG. Proceedings... Belo Horizonte, MG: SEAD, Treinamentos e Coaching, 2019. p. 328-330.

    Abstract: The physical and optical interaction of aerosols in atmospheric processes are complex and have high temporal and spatial variability, representing uncertainties as, for example, the aerosol particles influence on the atmosphere energetic balance. The Duster is a LIDAR system (Light Detection and Ranging) located in Natal / RN, capable of working with four detection channels (355 nm, 532 nm p, 532 nm s and 1064 nm). Duster sends pulses of laser light to the atmosphere and detects the return signal that results from the interaction of light with aerosol particles in the atmosphere. The signal detected by the system is represented by the LIDAR equation, which describes the optical properties and the system geometric parameters. The solution for this equation is obtained by the Klett-Fernald-Sasano Inversion Method (KFS), which extracts the inverted optical properties as backscattering (β) and extinction (α) profiles. The present work brings the result of analysis in backscatter profiles of the LIDAR signal in channel 532 nm during the aerosol Monitoring Campaign Long-Range Transportation Over Natal II (MOLOTOV II) that occurred from November 2017 to February 2018. We applied the Monte Carlo method for the analysis of the error in DUSTER measurements, which employs random numbers sequences. Two days of signal measurements were selected, to deal with four groups files, within approximately 30 min each group (frequency acquisition every 10 seconds). N synthetic profiles, as height function, with a random number generator, were created. Algorithms were performed, which removed the measurements clouds, the dark profiles, the background noise and generated the Range Corrected Signal (RCS). The KFS was applied to the synthetic profiles to obtain a set of N solutions (backscatter and extinction coefficient profiles). The results show that the N optical property profiles presented a considerable variability, characterized by their standard deviation. This variability, calculated as the height function, is the random error estimate of the LIDAR signal associated with the inversion procedure. The observed aerosols, according to information from the Hysplit trajectory model, were originated from the Sahara desert.

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  • IPEN-DOC 27046

    OLIVEIRA, DANIEL C.F. dos S.; HOELZEMANN, JUDITH J.; LANDULFO, EDUARDO ; ALADOS-ARBOLEDAS, LUCAS; GUERRERO-RASCADO, JUAN L.. Aerosol optical properties in the atmosphere of Natal/Brazil by an AERONET network Sun-photometer. In: ALBUQUERQUE, TACIANA T.A. (Ed.); ANDRADE, MARIA DE F. (Ed.); SANTOS, JANE M. (Ed.) AIR POLLUTION CONFERENCE BRAZIL; COMMUNITY MODELING AND ANALYSIS SYSTEM SOUTH AMERICA, 4th, July 22-24, 2019, Belo Horizonte, MG. Proceedings... Belo Horizonte, MG: SEAD, Treinamentos e Coaching, 2019. p. 319-324.

    Abstract: The study of atmospheric aerosols contributes to the understanding of radiative forcing and global warming. In addition, aerosols may influence atmospheric chemistry, visibility, precipitation and human health. Since 2016, Natal (capital of Rio Grande do Norte, Brazil) has a Sun-photometer (CIMEL) of the RIMA-AERONET network that can identify the presence of biomass burning aerosols and desert dust from Africa. For this identification, it is aimed to characterize the optical properties of these aerosols present in the atmosphere of Natal. The level 1.5 data (version 3) provided by AERONET provide information on some aerosol characteristics such as Aerosol Optical Depth (AOD), Ångström Exponent (α), Single Scattering Albedo (SSA), Asymmetry Factor (g), Complex Refractive Index (N) and Volume Size Distribution (VSD). The analysis period was from August 2017 to March 2018. Aerosols were classified according to global climatologies and their optical properties were described. In addition, backward trajectories were modeled using the HYSPLIT model (version 4.8) to identify the predominant air masses origins. Aerosols present in the atmospheric column of Natal showed monthly mean AOD (500 nm)in the range of 0.10 to 0.(representing ~40%), monthly means of α (440-670 nm)between 0.6 and 0.8 (representing 30%), bimodal VSD with dominant coarse mode, SSA (440 nm) about 0.80, real part around 1.500, imaginary part ranging from 0.0125 to 0.0437 and g above 0.74. The classification showed mixed (60.4%), marine (30.7%) and mineral dust (8.9%) aerosols. The backward trajectories identified that, in about 51% of the cases, are originated from Africa.

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  • IPEN-DOC 27032

    BAPTISTA, M.S.; CADET, J.; DI MASCIO, P.; GHOGARE, A.A.; GREER, A.; HAMBLIN, M.R.; LORENTE, C.; RIBEIRO, M.S. ; THOMAS, A.; VIGNONI, M.. Guidelines for defining type I and II photosensitized oxidation. In: ASP CONFERENCE, May 21-26, 2016, Tampa, FL, USA. Abstract... Herndon, VA, USA: American Society for Photobiology, 2016.

    Abstract: Here, ten tips are presented for a standardized definition of type I and II photosensitized oxidation reactions. Because of varied notions of photosensitized oxidation reactions, a checklist of recommendations is provided for their definitions. Type I and type II reactions are oxygen-dependent and involve unstable species such as peroxyl radical and singlet oxygen. This exercise was an outgrowth of a mini-symposium on singlet oxygen chemistry in Cambury, Brazil in 2014.

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  • IPEN-DOC 27022

    RICCIARDI, R.I. ; BARROSO, A.C.O. ; ERMINE, J.L.. Metodologia para o alinhamento estratégico da gestão do conhecimento: uma aplicação em um centro de Radiofarmácia. In: GIRONZINI, EDUARDO M. (Ed.) SIMPOSIO INTERNACIONAL SOBRE EDUCACIÓN, CAPACITACIÓN Y GESTIÓN DEL CONOCIMIENTO EN ENERGÍA NUCLEAR Y SUS APLICACIONES, November 22-26, 2015, Cusco, Peru. Abstract... Lima, Peru: Sociedad Peruana de Radioproteccion, 2015. p. 72-73.

    Abstract: Introdução: A grande preocupação da Gestão do Conhecimento é o emprego de técnicas para que as empresas captem os conhecimentos necessários para seus trabalhos operacionais; desse ponto de vista, a visão operacional somente pode ser percebida entre os trabalhadores, orientada segundo seus interesses e vai elucidar a percepção do estado crítico dos conhecimentos e dos porquês. Também, a Gestão do Conhecimento deve estar alinhada com os objetivos e metas estratégicas da organização; desse ponto de vista, é necessário entender claramente a estratégia organizacional, que dará uma percepção dos conhecimentos estratégicos relevantes para atingir suas metas. Essa visão gerencial é alcançada com seus dirigentes, aqueles que planejam e formulam a estratégia. A presente metodologia proporciona uma visão bastante consistente e agregada, onde toda a organização é representada, sob o ponto de vista das duas visões, operacional e gerencial, confrontando-as para se obter uma visão mediana, assim, assegurar o alcance das metas e futuro em consenso com as tarefas operacionais. Material e Métodos: A metodologia mostra uma integração inovadora de 6 processos: identifi cação dos conhecimentos através de análise dos processos; reconfi guração dos conhecimentos em domínio e sua representação em mapas; análise critica do conhecimento envolvendo importância e vulnerabilidade; análise estratégica do conhecimento e sua representação em mapas; combinação e comparação das análises critica e estratégica e sugestão de ações. Esta metodologia foi aplicada no Centro de Radiofarmácia do IPEN (Instituto de Pesquisas Energéticas e Nucleares), através de questionários, entrevistas e observação, utilizando os métodos de análise quantitativa e qualitativa. Resultados e Discussão: Nós encontramos 56 conhecimentos críticos, 64 conhecimentos estratégicos e críticos, em um total de 211 conhecimentos; além de 20 conhecimentos estratégicos inexistentes. Conclusões: as razões das criticidades dos conhecimentos proporcionaram informações concretas para a sugestão das ações, a relevância estratégica e os níveis de criticidade indicaram a prioridade das ações.

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  • IPEN-DOC 27042

    GRANDISOLI, C.L.; ANA, P.A. da; COSTA, M.M.; ZEZELL, D.M. ; LINS, E.C.. Viabilidade da transiluminação dental como técnica de imageamento das estruturas internas do dente. In: CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 24., 13-17 de outubro, 2014, Uberlândia, MG. Anais... Bauru, SP: Canal 6, 2014. p. 2070-2073.

    Abstract: A Transiluminação Dental (TD) é uma técnica utilizada para obtenção de imagens das estruturas dos dentes que funciona através da detecção da radiação infravermelha transmitida através dos mesmos. Este trabalho visa apresentar a TD como técnica de imageamento das estruturas anatômicas internas do dente. Amostras de 16 dentes humanos foram divididas em grupos com espessuras entre 0.5 e 2.5 mm. Para captação das imagens foi utilizada uma câmera FPA InGaAs (900- 1700 nm; Xenics, Inc., Bélgica) e uma fonte de lâmpada halógena no infravermelho próximo (Ocean Optics, Inc., USA); além de filtros ópticos de 1000±10nm, 1100±10nm, 1200±10nm e 1300±50nm. Imagens foram capturadas para diferentes tempos de exposição do sensor da câmera. Os melhores resultados revelam a viabilidade de imageamento de estruturas de espessura de até 2,5 mm sem a utilização de filtros. Após a obtenção destes resultados, um experimento piloto foi realizado em mais 4 amostras de dentes íntegros a fim de detector a câmara pulpar dos dentes. Os resultados provaram a viabilidade da TD no imageamento dental.

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  • IPEN-DOC 27039

    GONÇALVES, KARINA de O.; SILVA, MONICA N. da; SICCHIERI, LETICIA B. ; SILVA, FLAVIA R. de O. ; COURROL, LILIA C. . Síntese verde de nanopartículas de ouro e aplicações no diagnóstico e terapia de aterosclerose. In: CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 24., 13-17 de outubro, 2014, Uberlândia, MG. Anais... Bauru, SP: Canal 6, 2014. p. 1874-1877.

    Abstract: As nanopartículas de ouro apresentam inúmeras aplicações na medicina, como por exemplo, a terapia fototérmica e o rastreamento de tumores (biomarcadores). Elas também podem ser utilizadas no transporte de drogas (drug delivery), genes e DNA. Foi recentemente demonstrada na literatura que a incorporação de nanopartículas de ouro na estrutura do ácido δ - aminolevulínco (ALA) melhora as propriedades fotodinâmicas da terapia. Neste estudo propomos estabelecer correlações entre alterações nas fluorescências da protoporfirina IX extraídas do sangue e o crescimento da placa de ateroma. Este estudo implica em determinar se as nanopartículas de ouro sintetizadas com ALA podem fornecer informações adicionais e permitir prever quais pacientes correm maiores riscos de doença cardíaca no futuro de forma não invasiva e de baixo custo.

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  • IPEN-DOC 27038

    SILVA, MONICA N. da; SICCHIERI, LETICIA B. ; SILVA, FLAVIA R. de O. ; GONÇALVES, KARINA de O.; ANDRADE, MAIRA F. de ; LANZONI, VALERIA P.; COURROL, LILIA C. . A análise da fluorescência do sangue de coelhos submetidos à dieta hipercolesterolêmica. In: CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 24., 13-17 de outubro, 2014, Uberlândia, MG. Anais... Bauru, SP: Canal 6, 2014. p. 1632-1635.

    Abstract: A aterosclerose é uma doença degenerativa crônica caracterizada pela presença de lesões com aspectos de placas ou ateromas em artérias de médio e grande calibre. É a causa primária de doenças cardiovasculares e infarto, que por sua vez representam a principal causa de morte por doença no mundo. Este estudo busca um potencial marcador de aterosclerose o que pode viabilizar um método diagnóstico minimamente invasivo e de baixo custo. Neste estudo coelhos da raça New Zeland foram submetidos à dieta hipercolesterolêmica. Em um primeiro estudo foram realizadas extrações do sangue e das artérias. Foi realizado o perfil metabólico dos coelhos após 20, 40 e 60 dias do início da dieta. As artérias excisadas foram analisadas por microscopia para verificação da instalação do processo aterosclerótico nos coelhos. No segundo experimento realizou-se a coleta de fezes semanalmente. Nosso objetivo foi à verificação das variações da quantidade de PPIX (protoporfirina IX) no sangue e nas fezes com o estadiamento da aterosclerose. Com as fezes obteve-se uma curva de calibração para a determinação da melhor quantidade de massa fecal para o melhor volume de acetona, para a extração da PPIX. O melhor resultado foi obtido com os valores 0,10 g de massa fecal para 400 microlitros de acetona. O estudo da extração da PPIX tanto no sangue e nas fezes mostrou o aumento da emissão de fluorescência da PPIX no grupo da indução hipercolesterolêmica, acompanhando o aumento dos valores de LDL (lipoproteína de baixa densidade). Este estudo identificou um potencial marcador de aterosclerose.

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  • IPEN-DOC 27026

    PEREIRA, T.M. ; DIEM, M.; BIRD, B.; MILJKOVIC, M.; ANA, P.A.; BACHMANN, L.; ZEZELL, D.M. . Caracterização por espectroscopia no infravermelho de colóides tireoidianos sadios e hiperplásicos. In: CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 24., 13-17 de outubro, 2014, Uberlândia, MG. Anais... Bauru, SP: Canal 6, 2014. p. 1115-1118.

    Abstract: O presente trabalho mostra a caracterização da Tiroglobulina contidos nos colóides tireoidianos por espectroscopia no infravermelho. A produção da tiroglobulina é alterada em pacientes com Bócio Nodular. Assim, as informações bioquímicas desta glicoiodoproteina podem ser utilizada como indicador desta disfunção. Os resultados utilizando espectroscopia no infravermelho revela diferenças bioquímicas nas conformação da proteína, hormônios e carboidratos.

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  • IPEN-DOC 27037

    ROSTELATO, MARIA E.C.M. ; SOUZA, CARLA D. de ; SOUZA, DAIANE C.B. de ; ZEITUNI, CARLOS A. ; TIEZZI, RODRIGO ; COSTA, OSVALDO L. da ; RODRIGUES, BRUNA T. ; MOURA, JOÃO A. ; FEHER, ANSELMO ; SORGATTI, ANDERSON ; MOURA, EDUARDO S. de ; MARQUES, JOSE R. de O. ; SANTOS, RAFAEL M. dos ; KARAM JUNIOR, DIB. Waste management protocols for Iridium-192 sources production laboratory used in cancer treatment. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 2038-2038.

    Abstract: Introduction: Brachytherapy is a form of treatment that uses radioactive seeds placed in contact or inside the region to be treated, maximizing the radiation dose inside the targeted areas. Iridium-192 is being used in brachytherapy since 1955. It presents emission energy in the “therapy region” (370keV) and is easily produced in a nuclear reactor (191Ir (n, γ) → 192Ir). Wires are an iridium-platinum alloy with 0.36 mm diameter and they can be cut in any needed length. They can be used in several types of cancer. The linear activity is between 1 mCi/cm (37 MBq/cm) and 4 mCi/cm (148 MBq/cm) with variations of 10% in 50 cm maximum. This activity values classified the treatment and low dose rate (0,4 à 2 Gy/h). The propose of this work is to present a waste management system in a cancer treatment radioactive sources production laboratory. Methodology and Results: The solid waste is previously characterized in the analysis phase. The contaminants are already known and they are insignificant due to their fast half- life. The iridium-192 half-life is 74.2 days, classified as very short half-life waste. The waste activity is adds to 8mCi (2.96x108 Bq) per wire. According to the CNEN-NN 6.08 standard, that presents the discharge levels, the limit is 1 kBq.kg-1 (2.7x10-5 mCi.kg-1). The radioactive waste generated during the I192 wires production has a weakly activity of 9.7 GBq.g-1. According to the standards, this activity is too high to be discarded into the environment. The waste must be managed following the ALARA principal using the R&R (retain e retard) system, that means, temporary storage and posterior discharge. Since every 4 months, maintenance is performed inside the hot cell used for production, the waste must be removed. Using the equation: 𝐴 = 𝐿 λ (1 − 𝑒−λt), the total calculated activity is 1.68 x 1016 Bq and 4.8 g mass at the end of each 4 months period. This amount is stored inside a shielding device that has 212.37 cm3 volume. The waste will take 9.8 years (calculated by 𝐴 = 𝐴0(𝑒−λt)) to decay to the discharge levels. To store 30 devices during 10 years, a space with 6,370 cm3 is necessary. The laboratory has enough space for this storage. Thus, the radioactive waste management can be performed through the R&R (retain and retard) system safely.

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  • IPEN-DOC 27036

    PEREZ, CLARICE F.A.; SAHYUN, ADELIA ; FREITAS, KENIA A.M.. Study on the protection planning actions and response to nuclear or radiological emergency. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 1783-1787.

    Abstract: Nuclear or Radiological emergencies can have as a consequence the rise of Deterministic effects, in the population involved, and/or Stochastic effects due to their doses. In these situations, protective actions need to be done in order to keep the doses in the affected population below the levels of deterministic effects and protective actions that might reduce the risk of stochastic effects should be adopted, minimizing the doses to reasonably achievable levels. This work presents a comparative study between the publication of IAEA Safety Series 109 and the document of the International Atomic Energy Agency GSG-2 "Criteria for Use in Preparedness and Response for a Nuclear or Radiological Emergency" regarding the effective dose value system to be used as a basis to trigger protection actions in the Planning and Response to Nuclear or Radiological Emergencies that can reduce the risk of stochastic effects.

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  • IPEN-DOC 27035

    TEIXEIRA, MARIA I. ; CALDAS, LINDA V.E. . Optical stimulated luminescence from citrine for high-doses dosimetry. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 1343-1343.

    Abstract: In the sterilization of medical and pharmaceutical products, food and flower preservation, and treatment of electrical cables and al-treatments of different materials is used the irradiation process by highdoses because it presents advantages varies.Several Brazilian stone samples were already studied at IPEN for use in radiation dosimetry, using the techniques of thermoluminescence (TL), optical absorption (AO) and optically stimulated luminescence (OSL). Different kinds of glasses and sand from Brazilian beaches were studied at IPEN and showed favorable characteristics for their use for high-dose dosimetry. The possibility of using semi-precious stones from Brazilian as topaz, amethyst and jasper, and jade samples from different parts of the world, have been studied and tested at IPEN, using the technique of thermoluminescence. The objective of this work was to study citrine samples for application in high-dose dosimetry, using the OSL technique. The thermal treatment for reutilization of the materials was 300oC during 1h in an unsealed oven. The samples were irradiated using a Gamma Cell-220 system of 60Co (dose rate of 1.47 kGy/h), with doses from 50 Gy up to 300 kGy. The reproducibility of the OSL response presented a maximum variation coefficient of 5.7%. The lower detection limit was obtained as 350 mGy for the citrine pellets. The results show that the OSL detectors based on citrine may be useful for high-dose dosimetry in industrial processes and in the sterilization process of materials in hospitals.

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  • IPEN-DOC 23677

    CARNEIRO, J.C.G.G. ; ALVES, A.S. ; SANCHES, M.P. ; RODRIGUES, D.L. ; LEVY, D.S. ; SORDI, G.M.A.A. . Basic characterization of a radioactive facility and evaluation of risk agents. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 892-899.

    Abstract: This is an exploratory and descriptive study with qualitative and quantitative approaches to investigate the basic characterization of a Brazilian radioisotope production facility through ample knowledge of the workplace, workforce, task performed and identification of present risk agents in labor environment. The studied sample was composed by 102 workers distributed in eight work processes. Data were collected from April 2013 to July 2014 by applying questionnaire forms and complemented by interviews and observations. The descriptive statistical analysis included ANOVA test and non-parametric tests, among others. For the purpose of this study, there was adopted a significance level of 5% (p<0.05). The analysis of socio-demographic variables demonstrated that male gender predominated in total sample (74.5%) and the mean age of the workers was (51.8 ± 1.7) years. The largest percentage of the responders (70.6%) was technician-level workers. Regarding task-related exposure, there was considered that all groups presented the same exposure profile. At the workplace, there were identified 17 risk agents, including physical, chemical, biological, ergonomic and accident risks. The workforce was categorized into 3 risk groups according to relative frequency distribution of the occupational risks. Among the sixteen qualitative variables studied at the workplace, only three of them did not demonstrate relative frequency. The only variable that showed association with the three risk groups was the possibility of the contact with ionizing radiation. The study provided an overview of the perception of occupational risk at the facility. According to the results obtained by statistical analysis, most of the qualitative variables presented statistically significant association (p<0.001) related to the occurrence of occupational risks. Even though the workers may be potentially exposed to different risk agents, the ionizing radiation was the main physical risk factor observed in this facility.

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  • IPEN-DOC 27011

    KUAHARA, LILIAN ; CORREA, EDUARDO ; POTIENS, MARIA da P. . Activimeter response behaviour analysis related to well depth. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 756-756.

    Abstract: The activimeter, instrument used to radionuclide activity measure, consist primarily of a well type ionization chamber coupled to a special electronic device. Its response, after calibration, is shown in units of the activity quantity (Becquerel or Curie). It also has a special holder designed to accommodate all kinds of syringes and vials containing the radiopharmaceuticals. Many factors influence the response of an activimeter such as the volume of the sample, its position inside the activimeter well and the geometry of the vials. The idea of this study is to find the better position inside the well to get the best activity values, positioning the holder in different profundity, simulating a clinical procedure. The reference activimeter used was the Secondary Standard NPL-CRC radionuclide calibrator, traceable to the National Physical Laboratory (NPL), England, taking as reference the depth of 400 mm. Two other activimeters were tested: Capintec, CRC-15BT model with the depth of 170 mm and one CRC-25R model with depth of 257 mm. They all belong to the Instrument Calibration Laboratory of IPEN, São Paulo, Brazil. The measurements were made using three radioactive check sources: Co-57, Ba-133 and Cs-137. Sources readings were taken at various depths inside the ionization chamber well. The results shown maximum variation of 14.28% for Co-57, 11.27% to Ba-133 and 8.8% to Cs-137. All measurements were compared with those values found for the reference depth in each activimeter. The variation found show the necessity of include this kind of determination in all quality control programs that are applied to an activimeter used by a Nuclear Medicine Service.

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  • IPEN-DOC 27010

    POTIENS JUNIOR, ADEMAR ; COSTA, NATHALIA ; CORREA, EDUARDO ; SANTOS, LUCAS ; VIVOLO, VITOR ; POTIENS, MARIA da P. . Tandem KAP meters calibration parameters by Monte Carlo Simulation using reference RQR radiation qualities. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 702-702.

    Abstract: The Kerma-area product quantity can be obtained by measurements carried out with a kerma-area product meter (KAP) with a plane-parallel transmission ionization chamber mounted on the X ray system. It is the integral of the air kerma over the area of the X ray beam in a plane perpendicular to the beam axis. This quantity has been important to establish the diagnostic reference levels (DRLs) all over the word. In this work the MCNP5 code was used to calculate the imparted energy in the air cavity of KAP meter and the spatial distribution of the air collision kerma in entrance plan of the KAP meter. From these data, the air kerma-area product (KAP) and the calibration coefficient for the KAP meter were calculated and compared with those obtained experimentally. The X-ray tube was easily modelled as well the complete tandem calibration set up was possible. The spectra of the diagnostic radiology RQR reference qualities measured were used as a source definition in the input card for the Monte Carlo simulation. The clinical KAP meter calibration coefficients were obtained experimentally and by Monte Carlo simulation. The differences between those values were about 2%, except for RQR 10 (5.45%). The uncertainties in Monte Carlo simulation were less than 0.5% in all cases and the FOM (Figure of Merit) was constant for a number of histories of 1 million.

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  • IPEN-DOC 27064

    SAHYUN, ADELIA ; GHOBRIL, CARLOS N.; PEREZ, CLARICE F.; SORDI, GIAN M. . The evaluation of the real alpha value in Brazil and its projection until the year 2050. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 444-444.

    Abstract: The real evolution of the alpha value in Brazil has been performed three times in 1993 and 2000 making use of the procedure advised by ICRP and in 2004 making use of the procedure recommended by the IAEA. In both, the first two papers were made various projections for the coming years until 2025. Because of the great social and economic crisis in which the country (Brazil) is going, we decided to reassess the alpha value of our country and compare it with the projections of the two previous papers. Therefor e, we decided to make a dollar correction from that time to the current dollar, comparing the purchasing power from that time to the current. This procedure has shown us the great gap of value in use and that the actual value should be two to three times h igher. By GDP per capita, we could calculate the alpha value updated to various countries including the European Union and compare them with the official value currently in use. In conclusion, we believe that all countries that adopt an alpha value should upgrade it to the present day.

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  • IPEN-DOC 27063

    SORDI, GIAN M. . Comments on the General IAEA Safety Requirements - Part 3 - and suggestions for the next publications. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 381-383.

    Abstract: The international recommendations in question are described 52 requirements specified from chapter 2 to 5. The first chapter states that the number of fundamental safety principles has been increased form 3 to 10. To implement these requirments, the IAEA mentions 14 main parties but it is not clear which party is responsible for each of the fundamental safety principles. Chapter 2 presents 5 general requirements for protection and safety and makes it clear the responsibilities and competence of the government and regulatory body. ; but the responsibilities and competence of the other 12 principal parties reported in requeriment 4 are not clear. Chapter 3, which includes 37 requirements, is the most extensive and deals with planned exposure situations. Due to its extension, chapter 3 is left for a future paper, in case my comments are considered of some value by the principal parties involved. Chapter 4, with 4 requirements, deals with emergency exposure situations; and in chapter 5, the 6 requirements are about existing exposure situations. As to the requirements exposed in chapters 1, 2, 4 and 5 I have verified that the responsibilities and competence of the government and the regulatory body are clearly specified, which is not true for the other 12 principal parties. It is concerning this specific matter that I have made comments and suggestions. I also discuss the matters that are not under the responsibility of the radiological protection services but of other parties. Could the radiation protection service as a whole or in part be delegated to others, including the attributions of registrants or licensees?

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  • IPEN-DOC 27062

    SORDI, GIAN M. . Comments on the General IAEA Safety Requirements - Part 3 - and suggestions for the next publications. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 298-303.

    Abstract: The international recommendations in question are described 52 requirements specified from chapter 2 to 5. The first chapter states that the number of fundamental safety principles has been increased form 3 to 10. To implement these requirments, the IAEA mentions 14 main parties but it is not clear which party is responsible for each of the fundamental safety principles. Chapter 2 presents 5 general requirements for protection and safety and makes it clear the responsibilities and competence of the government and regulatory body. ; but the responsibilities and competence of the other 12 principal parties reported in requeriment 4 are not clear. Chapter 3, which includes 37 requirements, is the most extensive and deals with planned exposure situations. Due to its extension, chapter 3 is left for a future paper, in case my comments are considered of some value by the principal parties involved. Chapter 4, with 4 requirements, deals with emergency exposure situations; and in chapter 5, the 6 requirements are about existing exposure situations. As to the requirements exposed in chapters 1, 2, 4 and 5 I have verified that the responsibilities and competence of the government and the regulatory body are clearly specified, which is not true for the other 12 principal parties. It is concerning this specific matter that I have made comments and suggestions. I also discuss the matters that are not under the responsibility of the radiological protection services but of other parties. Could the radiation protection service as a whole or in part be delegated to others, including the attributions of registrants or licensees?

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  • IPEN-DOC 23678

    LEVY, DENISE S. ; SORDI, GIAN M.A.A. ; RODRIGUES, DEMERVAL L. ; CARNEIRO, JANETE C.G. . Enhancing communication on Radiological Protection throughout Brazil. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 284-290.

    Abstract: This paper focus on the potential value of Information and Communication Technologies (ICTs) to enhance communication on Radiological Protection throughout Brazil. The servers processing power added to the technology of relational databases allow to integrate information from different sources, enabling complex queries with reduced response time. It is our objective to provide radioactive facilities a complete repository for research, consultation and information on radiological protection in an integrated and efficient way. This webbased project works informatization of Radiological Protection Programs according to the positive tree published by AIEA in its Safety Series No. 102, the most generic and complete tree for an appropriate and effective radiation protection program. Up to this moment, the website counts on concepts, definitions and theory about optimization and monitoring procedures, interrelating information, currently scattered in various publications, in order to meet both Brazilian and international recommendations. The project involves not only the collection and interrelationship of existing information in the several publications, but also new approaches from some recommendations, such as potential exposures. Only few publications develop expressively the issue and, even though they provide fundamental theory, there is still lack of knowledge of failure probabilities, which currently constitutes a broad research field in radiological protection. This research proposes the development of fault trees and the analysis of different scenarios, suggesting paths to quantify probabilistically the occurrence of potential exposures, as well as probabilities to reach a certain level of dose. It is our target to complete the system in a near future, including other relevant issues, such as safe transport of radioactive materials, emergency response, radioactive waste management and decommissioning, among others. We believe the use of information technology for the radiological protection programs shall contribute greatly to provide information to Brazilian radioactive facilities throughout the country, spreading information to as many people as possible, minimizing geographic distances and stimulating communication and development.

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  • IPEN-DOC 27060

    SAHYUN, ADELIA ; GHOBRIL, CARLOS N.; PEREZ, CLARICE F.; SORDI, GIAN M. . Some suggestions to adequate the IAEA Safety Standards Series No. 49 according to the General Safety Requirements Part 3 from IAEA. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... The International Radiation Protection Association, 2016. p. 224-227.

    Abstract: At that time of publication SSR49 two exposure situations were considered, namely: practices and interventions, with Naturally Occuring Radioactive Material (NORM) being considered as intervention exposures but acknowledging that some natural sources can have exposures resulting from practices. In the Ba sic Safety Standards (BSS) the exposure situations have been categorised as planned, emergency and existing. These three situations necessitate an update of SSR No.49 since NORM fits in the existing situation, i.e one in which the doses already exist and should be reduced. To reduce the doses will create radioactive waste that must be either treated or stored. This scenario raises a problem of defining the dividing line between existing and planned situations. The point of transistion from one situation to the other needs to be clarified in order to establish the necessary controls for an existing situation whilst providing the necessary controls needed for the planned situation. For the latter planned situation several questions arise as to whether certain requirements can be exempted and under what circumstances. This paper will examine what the authors consider most important in more detail with some suggestions made for further consideration.

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  • IPEN-DOC 27059

    GARCIA, V. ; SOLE, S.V. ; BOIANI, N.F. ; ROSA, J.M.; BORRELY, S.I. . Evaluation of toxicity and color reduction of Reactive dye Yellow 160 and Red BG-3B, and textiles effluents after treatment by electron beam. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 110-110.

    Abstract: Textile effluents are always collored due to the amount of dyes lost during dieying processes. The low biodegradability and high solubility makes these compounds (reactive dyes) difficult to be enough removed by conventional treatment processes. The objective of the present study is to assess toxicity of Reactive dye Yellow - 160 and Red BG-3B as well as raw effluents containing such dyes. Acute toxicity tests were carried out with reference aquatic organisms: Vibrio fischeri bacteria and Daphnia similis microcrustaceans. After this, the effluent is also submitted to EBI treatment (irradiation at electron beam accelerator) for reducing color, with 0.5 kGy to 20 kGy doses. 100% of daphnids survived at 1g.L-1 of RY-160, and for Red BG-3B (C=0.564 g.L-1) EC 50% (48h) = 69.0 ± 0.66 . Raw textile effluent with dye RY-160 resulted in EC 50% lower than 2% for both organisms (D. similis EC 50% (48h) = 1.74 ± 0.53 and 0.6 ± 0.29, V. fischeri (15 min). For raw textile with Red BG-3B: D. similis EC 50% (48h) = 6.73 ± 0.72. The EBI treatment was effective for color removal, efficiency superior to 90% at 10 kGy. The data demonstrated the importance of evaluating not only dyes but also the effluent, since it has several additives that contributed to the high toxicity.

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  • IPEN-DOC 27058

    MARTINI, G. ; VIVEIROS, W.; FRANÇA, D.D.; QUINAGLIA, G.; RAIMUNDO, C.C.; LOPES-FERREIRA, M.V.; ROGERO, S.O. ; ROGERO, J.R. . Fish Embryo Toxicity Test (FET) to evaluate atrazine effects. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 83-83.

    Abstract: Surface water samples from São Paulo state were collected to perform Bioluminescent Yeast Estrogen Screen (BLYES) and chemical analyses (LC-MS/MS). Results showed environmental concentrations of atrazine from 2 to 43 ng L-1 on chemical analyses. Some studies have been performed to evaluate toxic effects on non-target organisms (fish) using herbicides such as Atrazine, a moderately toxic compound classified as an endocrine disrupting chemical (EDC) that can affect reproduction of several aquatic organisms with a compromise of vitellogenin production. To determine toxicity on embryonic stages of fish to different environmental chemicals and waste water, Fish Embryo Toxicity Test (FET) was designed using Danio rerio as model specie on this test, according to OECD 236 or ISO 15088 protocols, however these protocols observe only acute toxicity based on endpoints such as coagulated eggs, nondetachment of the tail, lack of heart beating and lack of somite formation. Some abnormalities can be recorded after the exposure on FET test but they are not considered as endpoint, neither any other compromised biomarker by EDC action. In order to evaluate the possibility of using these chronic endpoints and to verify if those environmental concentrations of atrazine are ecologically relevant, compromising reproductive aspects, FET test using Danio rerio were performed to assess lethal concentrations, sublethal concentrations and vitellogenin quantification after atrazine exposure. Occurrence of morphological abnormalities (microcephaly, spine curvature, edema, reduced size) and mortality of the embryos were determined exposing 20 fertilized eggs to atrazine concentrations from 2 to 64 mg L-1. The LC50 and EC50 were obtained after 96 hours of exposure. Organisms that survived each concentration were frozen to further vitellogenin quantification. Preliminary average concentrations obtained (LC 50; 96h= 48.15 mg L-1 and EC 50; 96h= 27 mg L-1) were considerably higher than concentrations observed on environmental samples. Therefore, surface water concentrations would not cause mortality or deformity in fish emphasizing the necessity to observe possible effect on vitellogenin concentration. Data will be analyzed and compared with the environmental concentration of atrazine to stablish the potential application of vitellogenin as endpoint on FET test.

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  • IPEN-DOC 27056

    GIMILIANI, G.T. ; FONTES, R.F.; ABESSA, D.M.. Modeling the dispersion of endocrine disruptors in the Santos Estuarine System (São Paulo State, Brazil). In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 64-64.

    Abstract: Estrogens are hormones responsible for growth and reproduction. They are naturally synthesized by animals and humans alike. Xenoestrogens are identical to natural hormones, but they are manmade and used as oral contraceptives. Xenoestrogens are a specific group of drugs found in domestic wastewater and some environmental matrices. These compounds remain after conventional sewage treatment and, consequently, affect both the environment and non-target aquatic organisms. In this study, we used the Delft3D hydrodynamic model to estimate the amount of both natural and synthetic estrogens that have been released in the Estuarine System of Santos and São Vicente and the Santos Bay. The data on flow from the sewage treatment plants and on average concentrations of natural and synthetic estrogens released in aquatic environments were obtained from the literature. The results of the modeling showed higher concentrations of estrogens in the estuarine waters of the Largo Pompeba region, the São Vicente Canal, and the Santos Bay, which are regions that receive greater inflows of domestic sewage. The results also suggest that higher concentrations of estrogenic compounds are expected to be found in areas with higher levels of salinity.

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  • IPEN-DOC 27055

    CUNICO, P.; FUNGARO, D.A. ; KUMAR, A.. Toxicity studies applied to evaluate the modified zeolites adsorbent for treating copper-complex dyes from simulated dyehouse wastewater. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 35-36.

    Abstract: Textile dyes occur in wastewaters in different concentrations due to their poor fixation to fabrics. Even at low concentrations, textile dyes can cause waste streams to become highly colored. Aside from their negative aesthetic effects, certain textile dyes have been shown to be toxic, and in some cases, these compounds are carcinogenic and mutagenic. Zeolite synthesized from fly and bottom ashes and modified with hexadecyltrimethylamonium (ZMF and ZMB, respectively) were used as adsorbent to remove dyes - Solophenyl Navy and Solophenyl Turquoise and their hydrolyzed forms Solophenyl Navy Hydrolyzed and Solophenyl Turquoise Hydrolyzed, respectively, from simulated textile wastewater. The purpose of the research was to use bioassays with Lemna minor, Ceriodaphnia dubia and Chironomus tepperi to determine the acute and chronic toxicity of these dyes before and after adsorption process. The acute results indicated C. tepperi showed to be less sensitive when compared with other test organisms, showing values of 48hLC50 70.8 and 211 mgL-1 for SN and ST. On the other hand, C. dubia showed to be very sensitive to the dyes tested (48hLC50 1.25; 54.5; 0.78 and 2.56 mgL-1 for SN, ST, SNH and STH), while L. minor presented response for higher concentration of the dyes, as chlorosis, loss of roots, reduction of the size and etc., showing values of EC50 of 18.9; 69.4; 10.9 and 70.9 mgL-1 for SN, ST, SNH and STH). Chronic tests with C. tepperi showed changes in survival, growth, development and gender differences for SN and ST dyes. After adsorption treatment with ZMF the acute effects were substantially reduced for both dyes and their hydrolyzed forms, showing absence of toxicity after treatment. However, the treatment with ZMB showed no difference and/or increased toxicity in some cases. Toxicity Identification Evaluation testes were realized and showed the baseline acute effects were substantially reduced after treatment with Ethylenediaminetetraacetic acid, showing the most of the toxicants in this study are cations metals. These experimental results suggest both dyes, raw and hydrolyzed, are toxic and their removal are necessary.

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  • IPEN-DOC 27054

    FERNANDES, I.; SOUSA, E.P.; GASPARRO, M.R.; CATHARINO, M.G. ; CERAVOLO, M.; CAMARGO, J.; LINS, C.G.. Sensitivity of Nitokra sp copepod exposed to UVA and UVB filters used in commercial formulations. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 65-66.

    Abstract: Large discharges of pollutants released in the marine environment have as final destination the sediment, affecting the quality and biodiversity. Pharmaceuticals and personal care products (PPCPs) are lipophilic and poorly biodegradable, with potential for bioaccumulation and persistence in the environment. Compounds from commercial sunscreens are found in the oceans, because they are often used by people. This study evaluated the acute effect of UVA and UVB filters - Benzophenone-3 (BZ- 3), Octyl Salicylate (OS) and Octyl Methoxycinnamate (OMC), detected in commercial sunscreens, performing the test both in a mixture as isolated – using Nitokra sp copepod and the method described in ISO14669:1999. When exposed to the water soluble fraction of the UV filters mixture, the mean of LC50-96h was 11.47 %, corresponding to 190 mg.L-1 of BZ-3, 150 mg.L-1 of OS and 230 mg. L-1 of OMC, while the isolated UV filter showed a tendency to increased lethality.The tests were performed in parallel with the reference substance DSS, and were within the acceptability limits of the LECOTOX LC50-96h = 7.76 (3.98-11.55) mg.L-1 DSS. It was concluded that the test organism and the method used were suitable for the tests with the commercial UV filters mixture and that, although the filters used are fatsoluble, there are bioavailable concentrations in the environment. The tested mixture caused deleterious effects to Nitokra sp. in concentrations lower than ANVISA (2006) allows, therefore more research is needed.

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  • IPEN-DOC 27053

    PUSCEDDU, F.; SANTOS, D.R.; MORENO, B.B.; GUIMARÃES, L.; CORTEZ, F.S.; PEREIRA, C.D.S.; CHOUERI, R.B.; SANTOS, A.R.; ROGERO, S.O. ; ROGERO, J.R. ; CESAR, A.. Marine sediment contamination in a subtropical zone (Santos Bay, Brazil): pharmaceuticals, personal care products and cocaine. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 64-64.

    Abstract: Although the continuous input of domestic sewage in coastal areas has been reported, few data are available about the presence of pharmaceuticals and personal care products (PPCPs) in coastal environments of South America. The aim of this study was to determine the environmental concentration of PPCPs and cocaine in sediments from Santos Bay (Brazil), a degraded coastal area due to urban and industrial pollution. A sediment sample, collected at five points around the Submarine Sewage Outfall of Santos, was analyzed by liquid chromatography-tandem mass spectrometry (LCMS/ MS) and 35 compounds were investigated. The presence of five pharmaceuticals (caffeine, carbamazepine, diclofenac, fluoxetine and ibuprofen), one personal care product (triclosan), and one illicit drug (cocaine) was evidenced. Considering the absence of information about the occurrence of PPCPs and illicit drugs in marine sediments of tropical and subtropical areas of South America, the data reported here subsidize the \nassessment of environmental risks of such substances in coastal zones.

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  • IPEN-DOC 27052

    CAMARGO, J.; SOUSA, E.P.; CATHARINO, M.G. ; GASPARRO, M.R.; ABESSA, D.M.; FERNANDES, I.; LINS, C.G.; VASCONCELLOS, M.B. . Lysosomal stability in oysters Crassostrea sp. from three different populations from the coast of São Paulo, Brazil. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 39-39.

    Abstract: Coastal zones continuously receive inputs of contaminants, which greatly affect its quality. Biological effects resulting from environmental pollution are complex and have not been properly estimated by chemical analysis and toxicity tests. A reliable form to assess the environmental quality consists of analyzing organisms exposed to constant, complex and diffuse sources of contamination. The appropriate use of biomarkers in sentinel organisms may provide an estimate of the potential risk associated with contamination. This study aims to evaluate if different levels of potential contamination affect differently the stress responses in oysters from three sites along the coast of São Paulo state. The physiological condition of oysters Crassostrea sp. from Cananéia (reference site), Santos and Bertioga was studied by analyzing the lysosomal membrane stability in haemocytes, measured using the neutral red retention time (NRRT) assay. Adult organisms were collected in spring (August, September, and October/2016) and autumn (April and May/2017). During the spring, the times of retention of the neutral red dye were similar in oysters from different sites and the reference area (p > 0.05). Interestingly, an uncommon red tide occurred along the coast of the state mainly affecting Cananéia, which may have influenced the reduction of the NRRT for oysters from this region. Such biological events (algal blooms) are more likely to occur at this time of year due to the typical climatic conditions, and may have the potential to even the adverse effects of pollution on distinct bivalve populations subject to different levels of contamination. During the autumn campaign, organisms from both contaminated sites (Santos and Bertioga) showed significant reduction in the mean NRRT relative to the reference site (p < 0.05). A previous study in the same region (Catharino et al., 2015) observed that in both seasons the oysters from Cananéia had a higher NRRT than the oysters from the other two sites. Overall, the NRRT were lower in the present study. These results may be due to the exposure of the organisms to pollutants, since lysosomes are organelles that absorb a wide variety of organic and inorganic substances. However, further investigations are required and being carried out to confirm this hypothesis.

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  • IPEN-DOC 27050

    ARAUJO, ELAINE C. ; ANDRADE, IZABEL da S. ; MACEDO, FERNANDA de M. ; CORREA, THAIS ; SALANI, MARIA H.G. de A. ; COSTA, RENATA F. da; RAMOS, SERGIANA dos P.; MARQUES, MARCIA T.A. ; LOPES, DANIEL S.; GUARDANI, MARIA L.G.; LANDULFO, EDUARDO ; GUARDANI, ROBERTO. Correlation study between air quality data and the Lidar system in Cubatao, Sao Paulo. In: SANTOS, JANE M. (Ed.); ANDRADE, MARIA de F. (Ed.); ALBUQUERQUE, TACIANA T.A. (Ed.) COMMUNITY MODELING AND ANALYSIS SYSTEM SOUTH AMERICA CONFERENCE, 3rd; AIR QUALITY CONFERENCE BRAZIL, August 28-31, 2017, Vitória, ES. Proceedings... Vitória, ES: Fundação Espírito-santense de Tecnologia, 2017. p. 175-177.

    Abstract: We present here the results of two methods with a scanning multiwavelength elastic lidar system and Beta Ray method (CETESB) realized in an industrial area. The objective is a comparer of these two methods to identify fixed sources of aerosol and to monitor plume dispersion. The results of the two aligned techniques indicate that can provide information on the concentration, spatial and temporal distribution of aerosol.

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  • IPEN-DOC 27045

    KOSKINAS, M.F. ; YAMAZAKI, I.M. ; DIAS, M.S. . Standardization of 59Fe by 4π(PC)β-γ software coincidence system. In: INTERNATIONAL CONFERENCE ON RADIONUCLIDE METROLOGY AND ITS APPLICATIONS, 20th, June 8-11, 2015, Vienna, Austria. Abstract... 2015. p. 127-127.

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  • IPEN-DOC 27043

    SUGAHARA, TARCILA; MOMTORO, FABIANO E.; MARTINS, GISLENE V.; MASSI, MARCOS; REIS, ADRIANO G. dos ; REIS, DANIELI A.P.. SiC/Cr thin films deposited by HiPIMS on Ti-6Al-4V used as protective coating in creep tests. In: CONGRESSO BRASILEIRO DE APLICAÇÕES À VACUO NA INDÚSTRIA E NA CIÊNCIA, 38.; WORKSHOP DE TRATAMENTO E MODI CAÇÃO DE SUPERFÍCIES, 3., 21-24 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 157-158.

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  • IPEN-DOC 27041

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; BRIGUENTE, LUCIANA A.N. da S.; MARCHETTO, LUIZ R.O.; LOPEZ, JAVIER O.. Microstructural evaluation of maraging 300 steel laser treated. In: CONGRESSO BRASILEIRO DE APLICAÇÕES À VACUO NA INDÚSTRIA E NA CIÊNCIA, 38.; WORKSHOP DE TRATAMENTO E MODI CAÇÃO DE SUPERFÍCIES, 3., 21-24 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 46-47.

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  • IPEN-DOC 27040

    CAVALCANTE, F. ; PECEQUILO, B.R.S. ; LEONARDO, L. . Activity concentrations of natural and artificial radionuclides in feline dry food. In: INTERNATIONAL CONFERENCE ON ENVIRONMENTAL RADIOACTIVITY, September 21-25, 2015, Thessaloniki, Greece. Abstract... 2015.

    Abstract: Natural radiation exposure is an inherent condition to all living species, once radionuclides from the 238U and 232Th chain can nearly be found in all places. Information on radionuclides concentration and exposure levels, from natural and anthropogenic sources are absolutely necessary to investigate the possible effects that ionizing radiation can induce. These can be very different depending on the organism considered and the exposure pathway. In recent decades, the exposure of non-human species to ionizing radiation has been specially considered and investigated (ICRP, 2014) by a vast number of scientists and organizations, once they differ widely from the exposure of human beings. Brazil holds the second largest cat and dog population in the world, consuming over 2 million tons of feed every year. The country also stands out for its production of pet food that produced 2.4 million of tons of feed in 2014, representing the world’s second largest industry. A novel study regarding the radionuclide content in different dog and cat food is being developed since 2013 and preliminary results have been presented by Cavalcante, F. and Pecequilo (2014), for selected dry dog food. The present study presents an evaluation of the radionuclide and radioactivity content of different brands of dry cat food, commonly found in local markets in the city of Sao Paulo, Brazil. Thirteen different samples were crushed into powder and kiln dried before tightly sealed in 100 mL HDPE flasks, with a plan screw cap and bubble spigot. These samples, after resting for 30 days to ensure secular equilibrium, were placed in an extended range coaxial germanium detector (Canberra XtRa GX4020 detector) for 150 ks and the acquired spectra were analyzed with the InterWinner 6.0 software (InterWinner, 2004). The natural radionuclides considered were 238U, 232Th and 40K, the anthropogenic radionuclides investigated were 60Co, 131I, 137Cs and 134Cs. The results for the considered artificial radionuclides have shown activity concentration values below the detector’s MDA (Minimum Detectable Activity), as in Table 1. The concentrations of natural radionuclides ranged from 1.12 ± 0.29 Bq/kg to 3.77 ± 0.36 Bq/kg for 226Ra; from 1.48 ± 0.40 Bq/kg to 6.27 ± 0.78 Bq/kg for 232Th and from 216.8 ± 11.2 Bq/kg to 361.7 ± 16.8 Bq/kg for 40K, as shown in Figure 1. The results suggest that the samples evaluated have no contamination of artificial radionuclides and the natural radionuclides concentration will not contribute to significant absorbed dose by their ingestion. Therefore, the authors conclude that these studied brands carry no radiological risk for the animals ingesting them.

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  • IPEN-DOC 27034

    VARCA, GUSTAVO H.C. ; BARROS, JANAINA A.G. ; BATISTA, JORGE G.S. ; SASOUNIAN, RAFAELA; SILVA, GUSTAVO T.M.; ZAMARION, VITOR M.; KATTI, KATTESH V.; LUGAO, ADEMAR B. . Protein crosslinking onto gold nanoparticles by gamma radiation. In: DUDALA, JOANNA (Ed.); CIECHANOWSKI, MAREK (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 10-13, 2017, Kraków, Poland. Abstract... Kraków, Poland: AGH University of Science and Technology - Faculty of Science and Applied Computer Science, 2017. p. 43-43.

    Abstract: The use of gold nanoparticles for diagnosis and treatment of cancer has received great attention over the last decade. Particularly, the possibility to use them for theranostics has increased the interest in the medical and scientific community. Weak technological aspects are related to the low biological affinity and non-specific toxicity. The use of albumin is of highlighted interest as albumin has been associated to inorganic particles to overcome biopharmaceutical challenges, including site-specific delivery and other biopharmaceutical advantages. The current work addresses the use of radiation and its effects over the crosslinking of bovine serum albumin onto gold nanoparticles. The idea of crosslinking the albumin onto gold surface aims to improve the stability of the protein layer onto gold nanoparticles in biological systems. Gold nanoparticles were synthesized by green technology using resveratrol and albumin capping was performed by physiosorption followed by irradiation at doses of 2.5, 5, 7.5, 10 and 15 kGy using 60Co as a radioactive source. Nanoparticle properties were assessed by dynamic light scattering, UV/Vis spectrophotometry and transmission electron microscopy. Protein crosslinking was monitored by fluorescence studies and stability of the nanoparticles was evaluated by zeta potential and titration with sodium chloride. The results evidenced the formation of a protein layer onto gold nanoparticles and revealed a protein crosslinking by means of bityrosine as a function of irradiation dose. Stability was considerably improved by the presence of the protein layer and the crosslinked protein layer.

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  • IPEN-DOC 27033

    OLIVEIRA, JUSTINE P.R. de ; OLIVEIRA, MARIA J.A. de ; SILVA, ISABELA C. da ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. . Influence of different gamma radiation doses on PVA/gelatin based scaffolds. In: DUDALA, JOANNA (Ed.); CIECHANOWSKI, MAREK (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 10-13, 2017, Kraków, Poland. Abstract... Kraków, Poland: AGH University of Science and Technology - Faculty of Science and Applied Computer Science, 2017. p. 27-27.

    Abstract: The present work aimed to study the influence of different radiation doses on a polymer blend at cryogenic and room temperature by means of crosslinking formation, pore size, morphology, topography and mechanical properties. The scaffold was prepared based on two formulations, one composed by gelatin (7%, w/w) and PVA (5%, w/w), and the second by gelatin (10%, w/w) and PVA (5%, w/w). The formulations were separately solubilized in distilled water and heated up to 80 ºC under constant stirring for 1 hour. Posteriorly, both blends were disposed in circular glass moulds. Half of samples was frozen for at least 24 h and then irradiated at 15, 25 and 50 kGy. The other half was cooled at 4 ºC for at least 24 h and then irradiated using the same doses. After irradiation both sample groups were frozen and freeze dried. The scaffold was characterized in terms of structure and morphology by mechanical assays, differential scanning calorimetry, scanning electron microscopy, optical coherence tomography and infrared spectroscopy. In addition, platelet adhesion and release, and cytotoxic assays were also performed. Samples irradiated at 15 kGy presented pore size diameter of around 1.4 μm and porosity of 54%, while samples irradiated at 25 kGy, presented pore size diameter of around 1.1 μm and porosity of 49%. Optical coherence tomography showed that gelatin control samples presented more superficial degradation as irradiation dose increased, while PVA control sample presented higher integrity, indicating that this polymer is less sensitive to gamma radiation. The system presented suitable mechanical properties and the platelet adhesion and release assays showed that the scaffold presented adequate pore size range to host and release the platelets, and non-cytotoxic to platelets, featuring adequate properties to be applied as dressing for wound treatments.

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  • IPEN-DOC 27031

    MUNHOZ JUNIOR, A.H.; MIRANDA, L.F.; SILVA, L.G.A. ; OLIVEIRA, M.O. de; ANDRADES, R.C.; GOMES, G.C.. Use of gamma-alumina nanoparticles for drug delivery system for releasing acyclovir. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 154-155.

    Abstract: The sol-gel process is a method for preparing porous ceramics, vitreous and crystalline materials from molecular precursors. In this process, a lattice of oxide compounds is made through reaction of inorganic materials in aqueous solution. The sol-gel process may be used to produce nanoparticles of pseudoboehmite, which are employed in drug delivery systems, production of nanocomposites and in the synthesis of gamma-alumina [1,2,3]. The firing of pseudoboehmite produces pure gamma-alumina [4,5]. The use of nanoparticles in drug delivery systems is advantageous because it prevents repeated doses and also decreases the amount of drug intake, which not only enhance the therapeutic effect, but also reduces the risks of plasma concentration reaching toxic levels. The use of synthetic nanoparticles have attracted great interest for applications in drug delivery systems. Pure gamma-alumina obtained from pseudoboehmite is a synthetic aluminum compound with excellent adsorbent properties. In this work, gamma-alumina was obtained through pseudoboehmite firing to be used for in vitro release of acyclovir. The gamma-alumina was characterized by X-ray diffraction (XRD), Differential Thermal Analysis (DTA), Thermogravimetry Analysis (TG), Scanning Electron Microscopy (SEM) using secondary electron detector and EDS detector. The release profile was obtained by UV/Vis spectroscopy for in vitro analysis. The results indicate gamma-alumina is appropriate for release of acyclovir.

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  • IPEN-DOC 27030

    MIRANDA, LEILA F. de; GOULART, LEID J.P.; SILVA, LEONARDO G. de A. e ; DONADON, ALEXANDRE C.; YAMASAKI, FABIO Y.; MUNHOZ JUNIOR, ANTONIO H.. Characterization of polystyrene nanocomposites containing nanoparticles of pseudoboehmite obtained by sol-gel process. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 153-154.

    Abstract: Polymer nanocomposites are hybrid materials in which inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. These substances have high surface area allowing a better interaction with the polymeric matrix and consequently promote changes in the physical properties of the final composite with small additions of the same. The preparation of nanocomposites with polymer matrix allows in many cases to find a relationship between a low cost due to the use of lower amount of charge, reaching high level of performance. In this work, were obtained polystyrene nanocomposites with pseudoboehmite synthesized by the sol-gel process with different concentrations of pseudoboehmite using octadecylamine as a coupling agent. The nanocomposites were prepared by the melt intercalation technique and characterized by differential thermal analysis, thermogravimetric analysis, heat deflection temperature, Vicat softening point, mechanical and rheological tests. The results showed an increase in the thermal properties, hardness and tensile strength values and decrease in the melt index, impact resistance and tensile elongation, showing the interaction of the filler with the polymer matrix.

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  • IPEN-DOC 27029

    HEILMAN, S. ; SILVA, L.G.A. . Silver and titanium nanoparticles used as coating on polyurethane catheters. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 150-150.

    Abstract: Silver nanoparticles have been used in the medical area due to their remarkable antimicrobial properties [1]. In this sense titanium dioxide nanoparticles obtained by the sol-gel method were used as coating of catheters for subsequent impregnation of silver nanoparticles with gamma irradiation and electron beam at 25 and 50 kGy [2]. This work aimed to study the use of the silver nanoparticles and titanium dioxide as coating of polyurethane Central Venous Catheter (CVC) for antimicrobial activity. Furthermore the amounts of titanium and silver present in the coated catheters had been evaluated by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Therefore the Raman spectrometry was used to identify the polymorph of titanium oxide, rutile.

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  • IPEN-DOC 27028

    MIRANDA, F.; RODRIGUES, D.; NAKAMATO, F.Y.; FRAJUCA, C.; SANTOS, G.A.; COUTO, A.A. . Microstructure and properties of composite WC-8(Co, Ni): effect of the addition of SiC. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 99-100.

    Abstract: The WC-based cemented carbides, also called hard metals, are a family of composite materials consisting of carbide ceramic particles embedded in a metallic binder. They are classified as metal matrix composites (MMCs) because the metallic binder is the matrix that holds the bulk material together [1]. WC based composites are used in applications where a good combination of hardness and toughness are necessary [2]. It is usual to add more components as the tungsten carbide in a binder (Co, Ni) to build the microstructure. The hardness for the cemented carbides based on nickel, because of the addition of reinforcements SiC nano-whisker increases significantly [3]. In this work, the SiC was researched as an additional component for composite WC-8(Co, Ni). Four mixtures were prepared with SiC content ranging from 0 to 3.0 wt%. These mixtures were pressed (200 MPa) and green samples with 25.2 mm of diameter and 40g were produced. Sintered were carried out in Sinter-HIP furnace (20 bar). Two sintering cycles were investigated with 1380 and 1420°C, and the sintering time considered was 60 minutes. The relative density, hardness, linear and volumetric shrinkage were determined. Microstructural evaluation was performed by optical microscopy and scanning electron microscopy (SEM-FEG). The results showed that the addition of SiC promoted higher densification and grain growth. The hardness was higher for samples with SiC, so solid solution hardening of the binder was more effective than WC grain growth.

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  • IPEN-DOC 27027

    REIS, A.G. ; REIS, D.A.P.; ABDALLA, A.J.; OTUBO, J.; COUTO, A.A. . An in situ high-temperature X-ray diffraction study of phase transformations in maraging 300 steel. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 95-95.

    Abstract: The phase transitions in the maraging 300 steel were studied using high temperature X-ray diffractometry. Maraging are ultra-high resistant steels with Ni-Co-Mo-Ti presenting a broad range of application in key areas such as nuclear and aerospace industries [1]. Prolonged high temperature exposure would lead to the formation of equilibrium austenite and ferrite phases [2]. Solution annealed maraging 300 steel was continuously heated at a 10 ºC/min rate from ambient temperature until 900 ºC and X-Ray measurements were done at 25, 400, 500, 600, 650, 700, 800 and 900 ºC. Dilatometric curve at the same heating rate and temperature range were performed and the results were compared with high temperature X-Ray diffraction. The martensite to austenite transformation and vice-versa could be detected by both techniques, although the precipitation could be detected only by dilatometry, associated to low volume of precipitates to be detected by X-Ray diffraction. The effect of austenite reversion at 600ºC was also studied after at 1, 2, 3 and 4 hour of exposure, showing that the amount of reverted austenite is proportional of time exposure at high temperature.

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  • IPEN-DOC 27025

    FONSECA, DANIELA P.M. da ; MONTEIRO, WALDEMAR A. . Analysis by optical microscopy and x-ray diffraction of composite Cu-Cr-Ag-Al2O3 synthesized using powder metallurgy. Acta Microscópica, v. 26, Supplement B, p. 278-279, 2017.

    Abstract: The use of Nature's materials in favor of human beings has been present in its daily life for a long time, copper and its alloys have been used in function of the high thermal and electrical conductivity, good mechanical properties, resistance to corrosion, ease of fabrication and also by the high value of scrap [1]. Metal alloys can also be combined with other classes of materials in order to obtain new properties, superior to the original alloy, this union of two or more materials forms a composite [2]. The studied composite has a ternary metal alloy (copper, chromium and silver) as a matrix and a ceramic oxide (alumina) as the reinforcing phase. The addition of chromium, silver and small amounts of finely dispersed metal oxides in copper improves their mechanical properties and increases the operating temperature, causing little loss of conductivity. A possible application of this composite is in electrical contacts, electronic devices that break the passage of current in electrical circuits [1]. The objective of this study was the microstructural characterization by optical microscopy and X-ray diffraction of the composite Cu-Cr-Ag-Al2O3 processed by powder metallurgy. The samples used were fabricated in laboratory scale of 25 mm diameter, 3,5 mm  ℎ  4,0 mm of height and 6,5 g of mass, with the following chemical compositions: (a) 85% Cu – 15% Al2O3; (b) 90% Cu – 5% Cr – 2% Ag – 3% Al2O3; (c) 90% Cu – 5% Cr – 5% Al2O3; (d) 90% Cu – 7% Cr – 3% Al2O3; (e) 85% Cu – 5% Cr – 5% Ag – 5% Al2O3; (f) 90% Cu – 5% Cr – 3% Ag – 2% Al2O3; (g) 90% Cu – 3% Cr – 7% Al2O3. In order to obtain the samples, the powders were weighed on a precision balance (according to each composition), mixed manually and cold-compacted in uniaxial press with 450 MPa pressure and sintered in an EDG furnace under 10-3 torr of mechanical vacuum and 650 °C in 6 h. The samples were prepared metallographically and observed in an optical microscope, the micrographs indicated coalescing of the copper particles and other metallic elements and formation of porosity (figure 1). The X-ray diffraction data were collected for samples (a) and (e) using graphite monochromator, copper tube, 25º ≤ 2θ ≥ 90º and Δ2θ = 0,02, from the diffractograms the mean crystallite size (𝐷) and microdeformation (𝜖) were calculated using the Williamson-Hall graphical method where the approximate line has a linear coefficient equal to 1/𝐷 and the angular coefficient is equal to 4𝜖/𝜆 [3]. In both samples were identified the expected phases, in agreement with the composition, and an undesirable phase of copper oxide (figure 2). The Williamson-Hall method was not used for all phases because it requires the identification of at least three peaks. Optical micrographs indicated presence of porosity inside the structure and partial homogeneity, due to the non-dissolution of the elements involved in the metal alloy, it is necessary to do further special thermal treatments. In some samples, a third phase was recognized, whose composition demands microanalyses to be properly identified. Through the diffractograms it was possible to identify the phase of copper oxide possibly coming from the sintering stage, this phase is not desirable or this composite because it negatively influences its electrical and mechanical properties. The Williamson-Hall method obtained a straight line with good correlation and suitable values of mean crystallite size and microdeformation for the copper phase.

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  • IPEN-DOC 27024

    DIAS, RENAN A.F. ; MONTEIRO, WALDEMAR A. . Microstrutural evolution of nickel-based superalloy processed by Equal-Channel Angular Pressing (ECAP). Acta Microscópica, v. 26, Supplement B, p. 71-72, 2017.

    Abstract: The present work shows the microstructural (under optical microscopy) and Vickers hardness evolution of a nickel-based superalloy Inconel 600 (alloy 600) before and after deformed by Equal-Channel Angular Pressing (ECAP) that significantly modified the alloy microstructure and, consequently, its strength. Alloy 600 is an austenitic nickel-based superalloy with 72% nickel, 14-17% chromium and 6-10% iron and it is commonly used in structures and components that work in aggressive environments. The grain size plays a significant role in the mechanical properties in this alloy; so, it is important to understand how processing techniques modify the microstructure of the material. In fact, ECAP is a processing technique involving the application of severe plastic deformation (SPD) used in the manufacture of metals and alloys with ultra-fine grains (UFG) and therefore with extraordinary combinations of both high strength and high ductility [1]. For the research, alloy 600 rods, supplied by Multialloy, with 8 mm diameter, were heat treated at 1200 °C for 6 h (solution), as shown in Figs. 1a and 1b, to achieve a larger grain size. The generated products were machined to the final dimensions of the specimen (6 X 6 X 25 mm) shown in Fig. 1c and then processed by ECAP, at room temperature using route A, in a D2 tool steel die, whose angles Φ and Ψ are 120° and 0° (Fig. 1d). Samples were pressed repetitively through a total of three passes, the microstructural aspect of the samples after each pass are shown in Figs. 2 and 3 with different magnifications. Metallographic preparations were made in the transverse, longitudinal and normal directions, TD, LD and ND of each sample. Sanding step with grit 320, 600 and 1200 were used. Polishing steps included 3 um- and 1 um-diamond paste and 0.05 um-alumina suspension and finally they were etched for optical examination using Marble’s etchant (10 g CuSO4, 50 ml HCl and 50 ml H2O). The micrographs were taken with OLYMPUS optical microscope model BX51M, with magnifications of 100x and 200x. The hardness tests were conducted in a Buehler Micromet 2103 microdurometer in the LD of the samples. For each measurement, a load of 500 g was applied for 15 s. Five separate measurements were taken on each sample at randomly selected points and then averaged. In Figs. 1a and 1b, it is possible to see only 1 phase, a solid solution of Ni-Cr-Fe, a coarsed grain structure and annealing twins. There are slight changes in the microstructure after the first pass, some strain marks are seen. After the second and third passes the microstructure shows highly deformed grains, deformation and transition bands. The values of hardness (Tab. 1) show an increase after each pass. In summary, (1) the micrographs analysis shows all the transformations from an annealed state to a highly-deformed state; (2) the grains are yet elongated after 3 passes and possibly do not show an expected UFG structure; (3) deformation twinning is revealed and is possible to see strain marks, deformation and transition bands; (4) the hardness values increased due to the high strain imposed to the alloy.

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  • IPEN-DOC 27023

    LIMA, CASSIO A. ; CORREA, LUCIANA; ZEZELL, DENISE M. . Infrared spectroscopy determining the biochemical changes in premalignant skin lesions submitted to photodynamic therapy. In: WORKSHOP FTIR SPECTROSCOPY IN MICROBIOLOGICAL AND MEDICAL DIAGNOSTICS, 11th, October 19-20, 2017, Berlin, Germany. Abstract... 2017.

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  • IPEN-DOC 27021

    RODRIGUES, PATRICIA F. ; WHITEMAN, DAVID; VANABLE, DIMITRIUS; DEMOZ, BELAY; WALKER, MONIQUE; LANDULFO, EDUARDO . Comparison of the hygroscopic behavior of aerosols obtained by Raman LIDAR and nephelometry: the NASA Discover-AQ experience. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: The hygroscopic behavior of aerosols is of great interest in the recent decades because of the importance in computing the radiative forcing of aerosols in the energy balance of the planet. The last report of the IPCC in 2013 shows that the uncertainty associated to the interactions between aerosols and clouds is high, and more research in this area is needed in order to give more information about the indirect effect of aerosols. The LIDAR (Light Detections and Ranging) is a technique that can be used to study the hygroscopic growth of aerosols under varying relative humidity conditions, and the main advantage of the technique is the possibility of studying the hygroscopicity next to the saturation in an unperturbed atmosphere. During the NASA Discover-AQ in 2011, a Raman LIDAR operated at the Howard University in Beltsville, United States, at the same time a nephelometer inside an airplane was sampling the same aerosol population. Then, the hygroscopic growth factor of the aerosols was computed using both instruments, and the results are now being compared. In this work, the result obtained by the LIDAR will be shown and compared to the nephelometer results obtained by Ziemba et al (2013) for 05 July 2011. The different methodologies adopted are explained and discussed. The good agreement between both instruments shows LIDAR is a promising technique in this field of study.

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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.