Made available in DSpace on 2014-10-09T12:47:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:23Z (GMT). No. of bitstreams: 1 09023.pdf: 5020333 bytes, checksum: fad008e6f2df7382a16c31dafc1045b1 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:54:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:02Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

Orientadores: Celso Darío Ramos, Elizabeth João Pavin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-17T05:19:39Z (GMT). No. of bitstreams: 1 Oki_GlauciaCelesteRossatto_M.pdf: 1462381 bytes, checksum: fcc4e95fbf2ec65e6d9cf04335c52034 (MD5) Previous issue date: 2010 / Resumo: Introdução: A doença arterial coronariana (DAC) é frequentemente assintomática em pacientes diabéticos, o que faz os testes não-invasivos serem uma ferramenta essencial para a detecção precoce da doença. O objetivo deste estudo foi avaliar a perfusão miocárdica de pacientes com diabetes mellitus tipo 1 (DM1) e tipo 2 (DM2) assintomáticos, sem diagnóstico prévio de DAC ou acidente vascular cerebral. Materiais e métodos: Cinqüenta e nove pacientes consecutivos assintomáticos (16 DM1, 43 DM2) foram submetidos a cintilografia de perfusão miocárdica com sestamibi- 99mTc (CPM). Eles foram avaliados quanto ao índice de massa corpórea (IMC), controle metabólico do diabetes, dislipidemia, tipo de terapia para o diabetes, hipertensão arterial sistêmica, nefropatia, retinopatia, neuropatia periférica, tabagismo e história familiar de DAC. Resultados: CPM foi anormal em 25,4%: 12 com alterações de perfusão (2 DM1, 10 DM2) e 3 com disfunção ventricular esquerda isolada (3 DM2). Os mais fortes preditores de perfusão miocárdica anormal foram: idade igual ou maior a 60 anos (p = 0,017, OR = 6,0), neuropatia periférica (p = 0,028, OR = 6,1), nefropatia (p = 0,031, OR = 5,6) e ECG de esforço positivo para isquemia (p = 0,049, OR = 4,08). Conclusão: A isquemia miocárdica silenciosa ocorre em mais de um em cada cinco diabéticos assintomáticos. Os mais fortes preditores de isquemia foram: idade avançada, neuropatia periférica, nefropatia, retinopatia e ECG de esforço positivo para isquemia / Abstract: Introduction: Coronary artery disease (CAD) is often asymptomatic in diabetic patients, which makes non-invasive tests an essential tool for early detection of the disease. This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of CAD or stroke. Methods: Fifty nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with 99mTc-sestamibi (MPS). They were evaluated for body mass index (BMI), metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. Results: MPS was abnormal in 15 patients (25.4%): 12 (20,3%) with perfusion abnormalities (2 DM1, 10 DM2), and 3 with isolated left ventricular dysfunction (3 DM2). The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p=0.017; OR=6.0), peripheral neuropathy (p=0.028; OR=6.1), nephropathy (p=0.031; OR=5.6), and stress ECG positive for ischemia (p=0.049; OR=4.08). Conclusions: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia / Mestrado / Clinica Medica / Mestre em Clinica Medica

Made available in DSpace on 2014-10-09T12:36:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:04Z (GMT). No. of bitstreams: 1 04375.pdf: 2570523 bytes, checksum: 66673910e669a76a08e5020adcac30c0 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:37:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:15Z (GMT). No. of bitstreams: 1 12905.pdf: 6893791 bytes, checksum: 505c8ae6d27e32929e2edfaa656b4e81 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto Astronomico e Geofisico, Universidade de Sao Paulo - IAG/USP

Made available in DSpace on 2014-10-09T12:47:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:23Z (GMT). No. of bitstreams: 1 09023.pdf: 5020333 bytes, checksum: fad008e6f2df7382a16c31dafc1045b1 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:54:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:02Z (GMT). No. of bitstreams: 0 / Há décadas o estudo da migração de compostos químicos presentes nas embalagens de alimentos, tais como metais, monômeros residuais e aditivos, têm despertado interesse de vários setores da sociedade a fim de evitar a contaminação química. Neste trabalho foi realizada a irradiação de embalagens que foram postas em contato com simulante de alimentos visando avaliar a migração através do modelamento matemático do processo difusivo, compilado num método de simulação computacional para estudar o comportamento microscópio da migração dos elementos metálicos cádmio, cromo, antimônio e cobalto, presentes em plásticos metalizados de embalagens de alimentos derivados de leite, e do monômero - caprolactama, presente em embalagens poliméricas de nylon utilizadas no acondicionamento de carne, para o simulante de alimentos solução de ácido acético 3%. As simulações da migração do monômero -caprolactama foram comparadas com resultados obtidos experimentalmente por cromatografia gasosa de alta resolução (HRGC) e a simulação da migração dos elementos metálicos foi comparada com os resultados obtidos através do método de análise por ativação com nêutrons (AAN). Estes resultados experimentais foram realizados e cedidos por grupos de pesquisa parceiros neste projeto. O sistema embalagem-alimento foi discretizado no espaço unidimensional e no tempo e a equação diferencial parcial que define o processo difusivo, a segunda \"lei de Fick\", combinada com a equação do tipo Arrhenius para os efeitos térmicos, foram resolvidos utilizando diferenças finitas. A etapa final da resolução foi um sistema linear tridiagonal de equações resolvido pelo algoritmo de Thomas. Foram estudados, e em alguns casos até previstos, grandezas empíricas, como o coeficiente de difusão, a energia de ativação e o perfil de concentração das substâncias migrantes, permitindo a compreensão do processo de difusão e a estimativa da migração destes componentes sob influência de radiação ionizante. Houve alterações nos níveis de concentração inicial do monômero na embalagem. As simulações demonstraram que a migração é fortemente dependente do seu perfil de concentração inicial e, embora não tenha havido um processo de validação formal, o simulador mostrou excelente concordância com muitos resultados experimentais, mensurados por técnicas analíticas diferentes, sendo pois uma interessante ferramenta em estudos futuros da influência da radiação ionizante na migração de compostos de sistemas embalagemalimento. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

Batch experiments have been used to assess the sorption properties of a potential repository backfill, NRVB (Nirex Reference Vault Backfill). In this study, UO22+, Eu3+, Am3+ and Th4+ have been used as model radionuclides and ethylenediaminetetraacetic acid (EDTA), isosaccharinic acid (ISA) and humic acid (HA) as competing ligands. The NRVB is an effective scavenger of all radionuclides, with the majority sorbed within minutes. Ultrafiltration showed that for solutions of U in contact with NRVB, for the small amount of U remaining in solution, nearly all (79 %) was present as clusters or colloidal material in a very narrow and relatively small size range (0.9 – 1.4 nm); for Eu (> 94 %) is attached to large NRVB derived colloids or particulates; for Th (82 %) is present in the true solution; whilst for Am 58 % is in the true solution. High concentrations of EDTA (>0.01 M) were able to reduce the extent of sorption at apparent equilibrium for all metal ions. ISA was very effective as a competing ligand for all metal ions, generally at a lower concentration than EDTA in equivalent systems. Humic acid was found to be ineffective as a competing ligand at any realistic concentration. In all systems, there was evidence of significant irreversibility, with concentrations of EDTA and ISA that were able to prevent sorption unable to remove radionuclides from contaminated NRVB. For the uranyl systems, luminescence spectroscopy was used to analyse the mechanism of sorption. For CSH (calcium silicate hydrate), the spectra were consistent with surface complexation, followed by some degree of incorporation. For NRVB, the spectrum was dominated by a feature that was similar to uranyl sorbed to CSH as a surface complex and/or incorporated into the structure. There was also a minor component that was assigned as a calcium uranate like surface precipitate. The sorption data were fitted with a simple surface complexation model, which had a single surface binding site. The modelling showed that the uptake of all radionuclides is consistent with surface complexation or surface precipitation. The model was less effective at predicting the effects of the competing ligands on sorption. Thermodynamic speciation and surface complexation modelling were able to explain the behaviour in the systems qualitatively, but cannot be used to predict sorption absolutely.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-04-15T15:44:21Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DEFESA final.pdf: 1491112 bytes, checksum: 89527843dec44e6b139fde377f1bfe4e (MD5) / Made available in DSpace on 2016-04-15T15:44:21Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DEFESA final.pdf: 1491112 bytes, checksum: 89527843dec44e6b139fde377f1bfe4e (MD5) Previous issue date: 2015-08-31 / CNPQ / A biomonitoração do ar pode utilizar organismos que têm estreita relação ecofisiológica com a atmosfera e alto grau de acumulação de elementos estáveis e/ou instáveis. Dentro deste tema, as plantas epífitas têm sido amplamente utilizadas como biomonitores, sendo consideradas ferramentas eficientes na avaliação de deposição atmosférica. Contudo, não se tem estudos que evidenciem a eficiência de acumulação de 210Pb na espécie T. recurvata L. Com base nisto, o presente trabalho avaliou a aplicabilidade da Tilandsia recurvata L. para determinação do 210Pb, investigando o potencial de acumulação deste biomonitor em condições laboratoriais e quando exposto em uma região com níveis de radioatividade natural significativos, como é o caso da região de Paulista e Igarassu. Estes municípios estão inseridos na região urano-fosfática do Nordeste brasileiro. As espécies de T. recurvata L. foram coletadas, tratadas e acondicionadas em bolsas de náilon e separadas, posteriormente, para a realização dos dois experimentos. O experimento em laboratório consistiu na avaliação do potencial de acumulação de 210Pb pela T. recurvata L., onde os biomonitores foram acondicionados em recipientes com cúpula transparente e levados à casa de vegetação, e sob condições naturais foram submetidos a níveis controlados de exposição ao radionuclídeo em questão. O outro experimento baseou-se na instalação das espécies em pontos selecionados para monitoração em campo, nos municípios de Paulista e Igarassu. Após o término de exposição, as amostras foram secas em estufa, maceradas, dissolvidas e levadas às análises radioquímicas para determinação de 210Pb. A concentração de atividade de 210Pb para cada amostra foi medida em um detector proporcional de fluxo gasoso. Os resultados obtidos com este trabalho confirmam a importância da espécie Tillandsia recurvata L. como ferramenta para o estudo da biomonitoração do 210Pb, por apresentar respostas mensuráveis, configurando-se a eficácia dessa espécie como bioparâmetro de análise para o diagnóstico de 210Pb atmosférico, além de ser o primeiro resultado de biomonitoração ativa da dispersão de 210Pb, em condições laboratoriais e nas regiões de monitoração. / The air biomonitoring can be carried out using organisms having a close relation ecophysiologic with the atmosphere and a high degree of accumulation of stable and / or unstable elements. Within this theme, the epiphytic plants have been widely used as biomonitors, considering efficient tools in the evaluation of atmospheric deposition. However, do not have studies that show the 210Pb accumulation efficiency in the species T. recurvata L. Based on this, the present study evaluated the applicability of Tilandsia recurvata L. for determining the 210Pb, investigating the potential to accumulate in this biomonitor conditions laboratory and when exposed in a region with significant levels of natural radioactivity, as is the case of Sao Paulo and Igarassu region. These municipalities and are inserted into furan-phosphate region of Northeast Brazil.The T. recurvata L. species were collected, processed and packed in nylon bags and separated later to carry out the two experiments. The laboratory experiment was to evaluate 210Pb accumulation potential by T. recurvata L. where biomonitors were acondicion in containers with transparent dome and taken to a greenhouse and under natural conditions were subjected to controlled levels of exposure to radionuclide in question. The other experiment was based on the installation of samples at selected points for field monitoring in the municipalities of São Paulo and Igarassu. After the end of exposure, the samples were oven dried, macerated, dissolved and brought to radiochemical analysis for determination of 210Pb. The concentration of 210Pb activity for each sample was measured in a gas flow proportional detector. The results of this study confirm the importance of the species Tillandsia recurvata L. as a tool for the study of biomonitoring of 210Pb, by presenting measurable responses, setting the efficacy of these species as bioparameter analysis for diagnosis of atmospheric 210Pb, and be the result of the first active biomonitoring of 210Pb dispersion in laboratory conditions and in the monitoring regions.

Surface-bound particulates containing radionuclides in the environment can become airborne through the process of resuspension. Once airborne, these radionuclides can be inhaled or ingested to deliver an internal dose of ionizing radiation. To that end, the resuspension factor method is a powerful tool for predicting a person's exposure to airborne particles from surface contaminations, and therefore is used to determine protective and intervening measures. The resuspension factor is calculated as the ratio measured airborne to surface mass concentration and has been found to generally decrease exponentially with time. Current models of the resuspension factor are empirical and have failed to predict recent measurement, motivating a stronger basis and physical model for the system. Additionally, federal guidances conservatively suggest an unphysical model of particulate radioactivity impact wherein the entirety of the radiation is absorped. For this dissertation, two- and three-compartment catenary models were derived which build on measured resuspension rate constants under various influences. These models were fit to a set of historic observations of resuspension factors using an instrumental uncertainty-weighting to resolve the large variances early in time which otherwise inflate calculations. When compared to previous resuspension models, our physical models better fit the data achieving reduced-chi-squared closer to 1. An experiment was undertaken to validate our basic environment resuspension models in an urban environment without wind. A resuspension chamber is constructed by placing an acrylic tube atop a poured concrete surface and lowering a low-volume air sampler head from above. Europium oxide powder was dispersed upon the surface or from above the air sampling height to emulate ideal compartmentalized release scenarios, and air is sampled on an hourly, daily, or weekly basis. Sampler filters then were evaluated for Europium content using neutron activation and gamma spectroscopy. Hourly measurements following airborne release are within an order of magnitude of early-timeframe historic resuspension factors (~10^−6 m^−1), whereas daily and weekly measurements from surface release demonstrate a gradual decrease in resuspension factor (∼10^−8 m^−1). These results support a need to critically assess the resuspension factor definition and its relationship to "initial suspension" and the indoor background, non-anthropogenic resuspension. Finally, a simulated model was generated to demonstrate loss of alpha radiation from relevant transuranic radioparticles. This was accomplished using the Geant4 Monte Carlo particle transport code. This basic model demonstrated a clear loss of average intensity and energy of exiting particles which are both directly related to the absorped dose. The data shows a loss from 10 to 90% of intensity to occur at particle sizes approaching the range of alphas within them, and a loss of roughly half the initial alpha energy at around the same particle sizes. The results establish a first-order baseline for a particulate self-absorption model which complement existing dosimetry models for inhaled radionuclides.