Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-05-07T12:48:50Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComparacaoDoisProcedimentos.pdf: 2435494 bytes, checksum: bb92571f01159bc451f461fcc5ace31f (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-09-12T15:33:30Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComparacaoDoisProcedimentos.pdf: 2435494 bytes, checksum: bb92571f01159bc451f461fcc5ace31f (MD5) / Made available in DSpace on 2014-09-12T15:33:30Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComparacaoDoisProcedimentos.pdf: 2435494 bytes, checksum: bb92571f01159bc451f461fcc5ace31f (MD5) Previous issue date: 2009 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FINEP - Financiadora de Estudos e Projetos / A visão de cores consiste na discriminação de objetos com base em sua composição espectral, auxiliando na interação organismo-ambiente. Dentre os primatas, estima-se que a dicromacia seja uma característica compartilhada pela maioria das espécies platirrinas, sendo esta condição polimórfica e ligada ao sexo. O objetivo deste estudo foi comparar os resultados produzidos por equipamentos e softwares distintos para avaliar a tri/dicromacia em dois machos e duas fêmeas da espécie Cebus sp. Foram utilizados dois programas computadorizados: um envolvendo uma versão adaptada do Cambridge Colour Test e outro desenvolvido para o uso em sistema computacional padrão. Nos Experimentos 1 e 2 foi possível averiguar a condição tricromata de uma participante e dicromata dos participantes restantes. No Experimento 3, uma participante fêmea e um macho apresentaram desempenho dicromata compatível com o registrado nos experimentos anteriores. Neste mesmo experimento, uma participante fêmea apresentou desempenho tricromata compatível com o registrado nos experimentos anteriores. Concluiu-se com este estudo que condições favoráveis para a avaliação de visão de cores em primatas platirrinos podem ser edificadas envolvendo equipamento e software de baixo custo financeiro e de fácil programação. Entretanto, devido ao pequeno número de sessões realizadas com o equipamento de baixo custo, sugere-se a replicação do Experimento 3 e a realização de novas sessões com maior número de participantes e envolvendo novos arranjos de estímulos. Acredita-se que se novos dados corroborarem os produzidos aqui, este procedimento e equipamento poderá ser utilizado para avaliação de outras espécies platirrinas onde dados comportamentais são escassos. / Color vision consists in discrimination of objects based on their spectral composition, assisting in the organism-environment interaction. Among primates, it is estimated that the majority of the platyrrhines monkeys has a polymorphic and sex-linked dichromacy. The objective of this study was to compare the results produced by different equipments and softwares for assessment of tri/dichromatic conditions of two males and two females of the genus Cebus sp. Two computerized programs were used: one involving an adapted version of the Cambridge Colour Test and another one developed for a standard computational system. In Experiment 1 and 2 were possible to verify the trichromatic condition of one female subject and the dichromatic condition of the rest of the participants. In Experiment 3, a female and a male subject presented a dichromatic performance compatible to that one registered in previous experiments. In this Experiment, a female participant presented a trichromatic performance compatible to that one registered in previous experiments. It was concluded that favorable conditions for assessment of color vision in platyrrhines species can be built involving equipment and software with low financial cost and easy to program. However, due the few number of sessions with the low financial cost equipment, it is suggested the replication of the Experiment 3 and more sessions should be made with more subjects and involving new stimuli arrangement. It is believed that, if new data confirm the data produced here, this equipment and procedure can be used for evaluation of others platyrrhines species where behavioral data are scarce.

Nos travaux ont débuté par la synthèse diastéréo/énantiosélective de 14 béta-hydroxyandrostanes en faisant appel à une réaction de Diels-Alder visant la formation du cycle B. Nous avons ainsi préparé une large palette de 14 béta-hydroxyandrostanes naturels, non naturels, racémiques ou énantiopurs. Par exemple au départ de la 2-méthyl-cyclopentane-1,3-dione divers 14 béta-hydroxyandrostanes polyfonctionnalisés possédant 5 à 7 centres stéréogéniques ont été synthétisés. D’autre part, avec la (R) ou (S)-carvone comme diénophile, nous avons mis en évidence diverses réactions de Diels-Alder sous contrôle d’une résolution cinétique parallèle chemodivergente ce qui a donné accès à des 14 béta-hydroxyandrostanes et à leurs énantiomères optiquement purs. Par la suite, nous avons développé la synthèse diastéréospécifique de 1,3-oxazines racémiques ou énantiomériquement pures en traitant des alpha-alkyloxyamides polyfonctionnalisés par des acides de Lewis ou de Brønsted. Au départ de ces mêmes composés, nous avons également synthétisé des pyrrolizidinones et des indolizidinones polyfonctionnalisées en faisant varier la nature des acides de Brønsted. Une synthèse formelle de la (+/-)-tashiromine a ainsi été réalisée. Finalement, la dernière partie de nos travaux a été consacrée à l’obtention des systèmes tricycliques caractéristiques de la famille des cédranoides et de la famille des quadranes/subérosanes. Ces deux systèmes tricycliques ont été obtenus au départ de la cyclopentane-1,3-dione en utilisant comme étape clé une réaction de Morita-Baylis-Hillman intramoléculaire initiée par de la tri-n-butylphosphine. / In the first part of our work, we have developed highly diastereo/enantioselective Diels-Alder reactions to promote the synthesis of 14 beta-hydroxyandrostanes. Thus, numerous non-natural or natural racemic and optically pure 14 beta-hydroxyandrostanes were obtained. For example, starting from the 2-methyl-cyclopentane-1,3-dione, the synthesis of 14 beta-hydroxyandrostane derivatives bearing 5 to 7 stereogenic centers was readily achieved. Moreover, by using (R) or (S)-carvone as dienophile, the Diels-Alder reaction proved to be under a chemodivergent parallel kinetic resolution control leading to optically pure (ent)-14 beta-hydroxyandrostanes. The second part of our work was dealing with the synthesis of heterocyclic compounds like pyrrolizidinones, indolizidinones and 1,3-oxazines. For that purpose, we have shown that the latter were readily available by Lewis or Brønsted acids treatment of polyfunctionalized alpha-alkyloxyamides. Furthermore, by changing the nature of the Brønsted acid, pyrrolizidinones and indolizidinones derivatives were obtained allowing a formal synthesis of (+/-)-tashiromine. Finally, the synthesis of the tricyclic cores found in cedranoids and quadranes/subersonanes sesquiterpenes was achieved, the key step being a tri-n-butylphosphine promoted intramolecular Morita-Baylis-Hillman reaction.

Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-03-27T14:33:09Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 967305 bytes, checksum: c9d38853b7fb33f61c42d51cac59ada3 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-04-11T13:06:39Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 967305 bytes, checksum: c9d38853b7fb33f61c42d51cac59ada3 (MD5) / Made available in DSpace on 2017-04-11T13:06:39Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 967305 bytes, checksum: c9d38853b7fb33f61c42d51cac59ada3 (MD5) Previous issue date: 2016-10-11 / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / O potencial cortical provocado visual (VECP) são úteis na investigação de mecanismos da visão de cores e disfunções de visão de cores. Redes senoidais cromáticas são geralmente usadas para gerar o VECP, mas exigem medidas psicofísicas antes para realizar a equalização de brilho das redes. Uma alternativa pode ser a substituição delas por estímulos pseudoisocromáticas que fazem uso de ruído de luminância e forçar a percepção do alvo ser dependente de contraste cromático. Neste trabalho, comparamos VECPs gerados por redes senoidais cromáticas isoluminantes e redes pseudoisocromáticas. Esta pesquisa foi aprovada pelo Comitê de Ética em Pesquisa, Núcleo de Medicina Tropical da Universidade Federal do Pará, Protocolo # 570434. Sete tricomatas normais foram testados com redes sinusoidais cromáticas e redes ilusórios proporcionado pelo estimulo pseudoisocromático de 0,33, 0,66, 1, 1,33, 1,66, e 2 cpg, apresentado no padrão reverso (1 Hz) e padrão onset (300 ms) - offset (700 ms) modos. Os sinais foram registrados usando eletrodos de superfície, x30,000 amplificado, digitalizado a 1 kHz, e filtrada entre 0,1-100 Hz. VECP de reversão provocado por redes pseudoisocromáticas teve amplitude e latência semelhante em comparação com aqueles provocada por redes senoidais. VECPs onset-offset desencadeados por redes senoidais teve maior amplitude e menor latência do que os obtidos com o estímulo pseudoisocromático. Diferentes mecanismos visuais são responsáveis pelas respostas corticais provocado por estímulos ilusórios quando apresentado em diferentes modos de estimulação. / Visual evoked cortical potentials (VECP) are useful the investigation of color vision mechanisms and color vision dysfunctions. Chromatic sinusoidal gratings are generally used to elicit VECP, but they require long psychophysical measurements to match the perceptual brightness between their stripes. An alternative is to replace them by pseudoisochromatic stimuli which make use of luminance noise to mask brightness clues and force the target perception to be dependent of chromatic contrast. In this work, we compared VECPs generated by sinusoidal and pseudoisochromatic gratings. This research was approved by the Comitê de Ética em Pesquisa, Núcleo de Medicina Tropical, Universidade Federal do Pará, Protocol #570434. Seven normal trichromats were tested with chromatic sinusoidal gratings and illusory gratings provided by the pseudoisochromatic design of 0.33, 0.66, 1, 1.33, 1.66, and 2 cpd, presented in pattern reversal (1 Hz) and pattern onset (300 ms) – offset (700 ms) modes. The signals were recorded using surface electrodes, amplified x30,000, digitized at 1 kHz, and filtered between 0.1-100 Hz. Pattern reversal VECPs elicited by pseudoisochromatic gratings had similar amplitude and latency compared to those elicited by sinusoidal gratings. Onsetoffset VECPs elicited by sinusoidal gratings had larger amplitude and shorter latency than those obtained with pseudoisochromatic stimuli. Different visual mechanisms are responsible for the cortical responses evoked by illusory stimuli when presented in different stimulation modes.

Submitted by Nathalya Silva (nathyjf033@gmail.com) on 2017-05-30T15:36:59Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 1399042 bytes, checksum: 90d7af315a20900e30bafefdf4af2e73 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-06-06T21:59:46Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 1399042 bytes, checksum: 90d7af315a20900e30bafefdf4af2e73 (MD5) / Made available in DSpace on 2017-06-06T21:59:46Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PotencialCorticalProvocado.pdf: 1399042 bytes, checksum: 90d7af315a20900e30bafefdf4af2e73 (MD5) Previous issue date: 2016-09-28 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / O potencial cortical provocado visual convencional (VECP, sigla em inglês) apresenta polaridade positiva em resposta ao modo de apresentação reversa para estímulos cromáticos isoluminantes e estímulos de luminância, enquanto o modo de apresentação onset tem polaridade positiva em resposta a estímulos de luminância, mas negativa em resposta a estímulos cromáticos. Foi avaliado como o modo de apresentação afeta o VECP pseudo-aleatório gerado em resposta a estímulos de luminância e compostos (cromáticos e de luminância). Onze tricromatas normais e 17 voluntários discromatópsicos foram avaliados. Uma sequência-m modulou temporalmente os estímulos de grades senoidais com contraste de luminância e composto tanto para o padrão de apresentação reverso quanto para o onset. Uma rotina de correlação cruzada foi usada para extrair o kernel de primeira ordem (K1) e o primeiro e o segundo slice do kernel de segunda ordem (K2.1 e K2.2, respectivamente) das respostas ao VECP. Calculou-se a integral das amplitudes dos componentes do registro em um intervalo de tempo para a estimar a magnitude do sinal para cada condição de estímulo. Foi utilizada uma correlação cruzada normalizada para restar a similaridade dos componentes do VECP. Para avaliar como o tempo de interação afeta a amplitude do VECP foi calculado o valor quadrático médio (RMS, sigla em inglês) em uma janela temporal e correlacionado com ao intervalo de interação das respostas referentes ao slice do kernel de segunda ordem avaliado. Os componentes do VECP variaram segundo o modo de apresentação e a presença de contraste cromático verde-vermelho nos estímulos. Para os tricromatas, K1, K2.1 e K2.2 do padrão onset, bem como K2.1 e K2.2 do padrão reverso nas condições de estimulação composta apresentaram forma de onda predominantemente negativa em 100ms. Para os discromatópsicos, nas mesmas condições, foi observado pequena positividade ou pequena negatividade. Tricromatas apresentaram maior magnitude no VECP do que os discromatópsicos nas condições compostas no padrão onset em K1, no padrão onset e reverso em K2.1 e no padrão reverso em K2.2. Tricromatas e discromatópsicos tiveram amplitudes similares no VECP em resposta aos estímulos compostos no padrão reverso em K1, no padrão onset em K2.2 e em todas as condições de luminância. A correlação cruzada mostrou grande similaridade entre as formas de onda geradas pelo estímulo composto no padrão onset em K2.1 e no padrão reverso em K2.2, assim como entre o padrão reverso em K2.1 e K2.2. A amplitude do VECP foi menos quanto maior era o intervalo de interação das respostas. Nós sugerimos que K2.1 do padrão reverso composto é a resposta mais apropriada para o estudo da visão de verde-vermelho. / Conventional pattern-reversal visual evoked cortical potential (VECP) shows positivity for luminance and chromatic equiluminant stimuli while conventional pattern-onset VECP shows positivity for luminance pattern-onset and negativity for chromatic pattern-onset. We evaluated how the presentation mode affects VECPs elicited by luminance and compound (luminance plus chromatic) pseudo-random stimulation. Eleven normal trichromats and 17 red-green color-blinds were studied. Pattern-reversal and pattern-onset luminance and compound (luminance plus red-green) gratings were temporally modulated by m-sequence. We used a cross-correlation routine to extract the first order kernel (K1) and the first and second slices of the second order kernel (K2.1 and K2.2, respectively) from the VECP response. We integrated the amplitude of VECP components as a function of time in order to estimate its magnitude for each stimulus condition. We also used a normalized cross-correlation method in order to test the similarity of the VECP components. In order to assess how the interection time afects the VECP’s amplitude we calculate de root mean square (RMS) amplitude into differents time windows and correlated it with the response time interval relative to the sencond order kernel slice avaliated. The VECP components varied with the presentation mode and the presence of red-green contrast in the stimuli. In trichromats, for compound conditions, pattern-onset K1, K2.1, and K2.2, and pattern-reversal K2.1 and K2.2 had negative-dominated waveforms at 100 ms. Small negativity or small positivity were observed in dichromats. Trichromats had larger VECP magnitude than color-blinds for compound pattern-onset K1 (with large variability across subjects), compound pattern-onset and pattern-reversal K2.1, and compound pattern-reversal K2.2. Trichromats and color-blinds had similar VECP amplitude for compound pattern-reversal K1 and compound pattern-onset K2.2, as well as for all luminance conditions. The cross-correlation analysis showed high similarity between waveforms of compound pattern-onset K2.1 and pattern-reversal K2.2 as well as pattern-reversal K2.1 and K2.2. The amplitude of VECP was smaller as higher was the response time interval. We suggest that compound pattern-reversal K2.1 is an appropriate response to study red-green color-opponent activity.

Introdução e Objetivo: Hidronefrose e Obstrução são condições associadas, entretanto dilatações da via excretora podem ocorrer na ausência de obstruções clinicamente importantes. Ultra-sonografia convencional e Renograma com Diuréticos são os métodos diagnósticos complementares mais utilizados na avaliação das hidronefroses na infância. Recentes trabalhos têm demonstrado a possibilidade de observarmos os jatos ureterais com o Estudo Ultra-sonográfico com Doppler Colorido e sugerido a sua aplicação no diagnóstico diferencial das hidronefroses. O objetivo do presente trabalho foi avaliar a aplicabilidade do estudo dos jatos ureterais como método diagnóstico na identificação das hidronefroses obstrutivas e não obstrutivas na população pediátrica. Métodos: Foram estudadas 48 crianças (35 meninos e 13 meninas) com idade que variou de um mês a 14 anos (mediana de 4 anos), que se apresentaram com Hidronefroses Unilaterais, Graus III e IV, e com suspeita de obstrução da junção pieloureteral. Todos os sujeitos foram submetidos ao Estudo dos jatos ureterais e ao Renograma com Diuréticos num período de duas semanas. As unidades hidronefróticas foram consideradas obstruídas quando a Função Renal Diferencial era menor do que 40%, ou em indivíduos mais velhos que apresentavam dor lombar intermitente. Os jatos ureterais de cada meato foram contados por um período de 5 minutos e considerados separadamente. Freqüência Relativa dos Jatos (FRJ) foi definida como o numero de jatos ureterais no lado afetado dividido pela soma dos jatos ureterais observados bilateralmente. Resultados: Vinte e duas (45,8%) unidades hidronefróticas foram consideradas obstruídas.A média da FRJ diferiu significativamente entre as hidronefroses obstrutivas (0,09 ± 0,15) e não obstrutivas (0,41 ± 0,11). (p<0.001). Análise da Curva ROC revelou que FRJ < 0,25 é o melhor valor que distingue as hidronefroses obstrutivas e não obstrutivas e o faz corretamente em 91,2 % dos casos, com uma Sensibilidade de 86,4% (IC95%=78,6-98,2%) e Especificidade de of 96.15% (IC95%=87.8-99%). O Índice de Probabilidade Positivo foi de 22,45 e a Razão de Chances Diagnóstica de 158,3. A área sob a curva ROC foi de 0,91 (IC95%=0,86-0,98) indicando a excelente acurácia do método. Conclusões: FRJ < 25 % mostrou ser um bom indicador de obstrução nas hidronefroses unilaterais da infância. O estudo dos jatos ureterais a Ultrasonografia com Doppler Colorido é método simples, não invasivo e pode ser utilizado na abordagem inicial e no seguimento, na diferenciação das hidronefroses obstrutivas e não obstrutivas na população pediátrica / Introduction and Objective: Hydronephrosis (HN) and obstruction are closely associated, but upper urinary tract dilatation can occur without significant obstruction. Despite some pitfalls, conventional ultrasonography and diuretic renography (DR) are the main modalities in the evaluation of HN in children. Recent reports have demonstrated the usefulness of Color Doppler Ultrasonography (CDUS) as a reliable method to identify the ureteric jets (UJ) in the bladder. The aim of this study was to evaluate CDUS evaluation of the UJ in the bladder as a diagnostic tool to distinguish obstructive from non-obstructive dilatations of the upper tract in pediatric population. Methods: We evaluated 48 patients (35 boys and 13 girls), aged 1 month to 14 years (median = 4 ys.), who presented with unilateral grade III and IV hydronephrosis suspicious of pyeloureteral junction obstruction. All patients underwent DR and evaluation of UJ by transverse CDSG of the bladder within a maximum of 2 weeks. Obstruction was considered in the DR when the hydronephrotic unit showed Differential Renal Function of less than 40%, or when symptomatic intermittent renal colic was present in older children. The number of UJ was counted over a 5 min period and its frequency was calculated for each ureteral orifice. Relative Jet Frequency (RJF) was defined as the UJ frequency of hydronephrotic side divided by total UJ frequency. Receiver-Operating Characteristic (ROC) plots were constructed to determine the best cuttoff for RJF, in order to identify renal units with obstructive hydronephrosis. Results:Twenty-two(45.8%) hydronephrotic units were considered obstructed. The mean RJF differed significantly between obstructive (0.09 ± 0,15) and non-obstructive hydronephrosis (0.41± 0.11)(p<0.001). ROC analysis revealed that RJF< 0.25 was the best threshold and it correctly discriminates obstruction in 91.2% of the childrens with a sensitivity of 86.4% (95%CI=78.6-98.2%) and specificity of 96.15% (95%CI=87,8-99%). The Positive Likelihood Ratio was 22.45 and Diagnostic Odds Ratio was 158.3.The area under the ROC curve was 0.91 (95%CI=0.86-0.98), indicating excellent discrimination power. Conclusions: In this study RJF < 25% was found to be a good indicator of obstruction in children with unilateral hydronephrosis. CDUS evaluation of UJ is an easy and non-invasive method that can be used as an initial diagnostic tool and in follow-up cases, to differentiate obstructed from non-obstructed hydronephrosis in the pediatric population

Este trabalho apresenta a medida do espectro de energia dos nêutrons no núcleo do Reator IPEN/MB-01. Para tal, foram inseridos detectores de ativação na forma de diminutas folhas metálicas no núcleo do reator, na região moderadora, utilizando um dispositivo articulado que permite que as folhas fiquem posicionadas na posição central do núcleo do reator, garantindo que todas as folhas sejam irradiadas na mesma posição. Os detectores de ativação foram selecionados de forma a cobrir grande parte do espectro de energia dos nêutrons no Reator, para tanto foram utilizadas folhas de Au197, Mg24, Ti48, In115, Sc45 entre outras. Após a irradiação os detectores de ativação foram submetidos a espectrometria gama num sistema de contagem de Germânio hiper-puro, o que possibilitou a obtenção da atividade de saturação por núcleo alvo, um dos principais dados de entrada do código computacional de desdobramento de espectro unfolding SANDBP, que através de um processo iterativo, ajusta o espectro que melhor se adequa ao conjunto de dados de entrada do código, composto principalmente pelas taxas de reação por núcleo alvo obtidas experimentalmente e um espectro inicial de entrada, neste caso obtido à nível celular pelo código Hammer-Technion para a célula representativa do núcleo do Reator, fornecendo assim a solução do espectro. / This work presents the neutron spectrum measurements in the Reactor IPEN/MB- 01 using very thin activation detectors in the metallic form, in reactor core, in moderator region. An articulated device allows that the foils are inserted in the central position of reactor core, ensuring that all the foils are irradiated in the same position. The activation detectors of different materials such Au197, Mg24, Ti48, In115, Sc45 and others, were selected to cover a large range of neutron spectrum. After the irradiation, the activation detectors were submitted to a spectrometry gamma by using a system of counting with high purity Germanium, to obtain the saturation activity per target nuclide. The saturation activity is one of the main data of input of unfolding code SANDBP, that through an iterative adjustment, modify the spectrum that better agree with the dataset of code input, composition mainly for measure reaction rate per target nuclide and a initial input spectrum, calculated for Hammer-Technion code, supplying a solution spectrum.

INTRODUÇÂO: A tireoidite crônica autoimune (TCA) é a principal causa de hipotireoidismo adquirido, o qual requer tratamento contínuo com levotiroxina (LT4). Até o momento, não há terapia capaz de regenerar o tecido tireóideo lesado e melhorar sua função. Como a terapia com Laser de baixa intensidade (LILT) foi eficaz em outras doenças autoimunes, bem como na regeneração de vários tecidos, o objetivo deste estudo foi avaliar a eficácia do Laser de baixa intensidade no tratamento de pacientes com hipotireoidismo decorrente de tireoidite crônica autoimune utilizando-se os seguintes parâmetros de resposta: a) o mapeamento dúplex-Doppler colorido da tireoide; b) a função tireóidea estimada pela dose de LT4 necessária para manter as concentrações séricas de T3 total, T4 total, T4 livre e TSH normais; c) as concentrações séricas de anticorpos antiperoxidase tireóidea (TPOAb) e antitireoglobulina (TgAb). MÉTODOS: Trata-se de ensaio clínico randomizado, placebo-controlado, conduzido no Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, de março de 2006 a março de 2009, no qual foram incluídos 43 pacientes com hipotireoidismo causado por TCA. Todos eles apresentavam altas concentrações séricas de TPOAb e/ou TgAb e padrão ultrassonográfico compatível com TCA. Os pacientes foram randomizados em grupo L (submetido à LILT, n = 23) e P (submetido ao placebo, n = 20). Os limites da tireoide foram demarcados com o auxílio da ultrassonografia. Pacientes do grupo L submeteram-se à LILT (830 nm) e os do grupo P à função placebo do mesmo equipamento. Ambos os grupos foram submetidos, no total, à 10 sessões, duas vezes por semana, com a mesma técnica. Realizou-se pré e 30 dias pós-intervenção: o estudo ultrassonográfico (US) pelo modo-B, que incluiu o histograma computadorizado de escala de cinzas para estimar quantitativamente o índice de ecogenicidade; o US-Doppler colorido de amplitude atribuindo-se valores de 0 a 4 para os padrões de vascularização e o US-Doppler pulsado para estimar a velocidade de pico sistólico e o índice de resistividade das artérias tireóideas superiores e inferiores. Após o segundo US, os pacientes descontinuaram a LT4, a qual foi reintroduzida para os pacientes que apresentaram hipotireoidismo, em dose suficiente para obter normalização hormonal. Realizaram-se determinações séricas de T3 total, T4 total, T4 livre, TSH, TPOAb e TgAb pré-intervenção e no 1º, 2º, 3º, 6º e 9º meses pós-suspensão de LT4. RESULTADOS: No US modo-B pós-intervenção, verificou-se aumento estatisticamente significativo do índice de ecogenicidade no grupo L (1,24 ± 0,11) comparado ao P (0,98 ± 0,07; P < 0,001), assim como a proporção de pacientes com volume normal foi estatisticamente maior no grupo L (P = 0,005). O US-Doppler colorido de amplitude mostrou que o valor do padrão de vascularização foi estatisticamente maior no grupo P (2,3 ± 0,27) do que no L (1,87 ± 0,36; P = 0,033). Observou-se redução da dose de LT4 no grupo L (38,59 ± 20,22 g/dia) comparada à do P (106,88 ± 22,9 g/dia; p < 0,001). TPOAb foi menor no grupo L (681,91 ± 317,44 U/mL) do que no P (1176,40 ± 551,9 U/mL; p = 0,043). Não houve redução de TgAb e efeitos adversos. CONCLUSÕES: A LILT foi eficaz no tratamento da TCA, uma vez que no grupo L verificou-se: a) melhora da ecogenicidade, do volume e do padrão de vascularização da glândula tireoide no mapeamento dúplex-Doppler colorido; b) melhora da função da glândula tireoide, evidenciada pela redução da dose de LT4 necessária para tratar o hipotireoidismo c) modulação parcial da autoimunidade, demonstrada por meio da redução das concentrações séricas de TPOAb / INTRODUCTION: A chronic autoimmune thyroiditis (CAT) is the main cause of acquired hypothyroidism which requires continuous treatment with levothyroxine (LT4). So far there has been no such therapy which can make the damaged thyroid tissue regenerate, improving its function. As the low-intensity Laser therapy (LILT) was effective in other autoimmune diseases, as well as in regenerating several tissues, the objective of this study was to evaluate the efficacy of LILT in patients with hypothyroidism caused by CAT by utilizing the following response parameters: A) Color Doppler ultrasonography of thyroid; B) The thyroid function estimated by the dose of LT4 in order to keep the serum concentrations of normal T3, T4, free T4 (fT4) and TSH; C) The serum concentrations of thyroid peroxidase (TPOAb) and thyroglobulin antibodies (TgAb). METHODS: This is a placebo-controlled randomized clinical essay guided at the Institute of Radiology, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo from March 2006 to March 2009, made up of 43 patients with hypothyroidism caused by CAT. All the patients showed high serum concentrations of TPOAb and/or TgAb and ultrasound pattern compatible with CAT. The patients were randomized in L group (submitted to LILT, n = 23) and P group (submitted to placebo, n = 20). The limits of thyroid were marked off with the help of ultrasonography. The patients in L group were submitted to LILT (830 nm) and the patients in P group were submitted to the placebo function of the same equipment. Both groups were submitted a total of 10 sessions, twice a week, using the same technique. Pre- and 30 days post-intervention were applied: ultrasonographic study (US) by B-mode, which included the grey scale computerized histogram to quantitatively estimate the index of echogenicity; the amplitude color Doppler US with values given from 0 to 4 for the vascularization patterns and the pulsed Doppler US to estimate the systolic peak velocity and the index of resistivity of superior and inferior thyroid arteries. After the second US the patients discontinued the LT4, which was later re-introduced in the patients having hypothyroidism in a certain amount so as to be sufficient to obtain hormonal normalization. Serum determinations of total T3, total T4, fT4, TSH, TPOAb and TgAb pre-intervention were accomplished and also in the 1st, 2nd, 3rd, 6th and 9th month post-suspension of LT4. RESULTS: In post-intervention B-mode US a significant increase in the index of echogenicity in L group (1.24 ± 0.11) was statistically observed compared with the P group (0.98 ± 0.07; P < 0.001), as well as the proportion of patients with normal volume was shown statistically higher in L group (P = 0.005). The amplitude color Doppler US showed the standard value of vascularization was statistically greater in P group (2.3 ± 0.27) than in L group (1.87 ± 0.36; P = 0.033). Pulsed Doppler US showed an increase in the systolic peak velocity of the inferior thyroid arteries in L group (34.47 ± 4.81 cm/s) in relation to P group (26.12 ± 4.29 cm/s; P = 0.016). A reduction in the dose of LT4 in L group (38.59 ± 20.22 g/day) was observed compared with the one in P group (106.88 ± 22.9 g/day; p < 0.001). TPOAb was smaller in L-group (681.91 ± 317.44 U/mL) than in P-group (1176.40 ± 551.9 U/mL; p = 0.043). There was no reduction of TgAb and adverse effects. CONCLUSIONS: LILT was effective in the treatment of CAT, once L group showed: A) amelioration of echogenicity, of volume and of vascularization of the thyroid gland in the color Doppler ultrasonography; B) improvement of thyroid function, featured through the reduction in the necessary dose of LT4 to treat the hypothyroidism; C) partial modulation of autoimmunity demonstrated by reduction of TPOAb serum concentrations

Afin d’optimiser le procédé de production de culasses automobiles en aluminium et d’améliorer sa fiabilité, une meilleure connaissance du comportement des noyaux de fonderie est nécessaire. Les noyaux sont des matériaux composés de grains de sable liés par une résine en faible proportion, et servent à mouler les conduits et cavités intérieurs des pièces métalliques. Au cours de leur cycle de vie, les noyaux sont amenés à subir de fortes températures et des sollicitations mécaniques complexes. L’objectif de cette étude est de caractériser le comportement thermomécanique des noyaux sous diverses sollicitations selon le taux de liant, la température et surtout l’état de dégradation de ce liant. En particulier, les travaux de cette thèse s’attardent sur les mécanismes d’endommagement et de fissuration des noyaux, dont la compréhension est la clé pour optimiser l’étape de débourrage qui consiste en la fracturation et l’élimination des noyaux. Les résultats de cette thèse serviront par ailleurs à nourrir un modèle numérique simulant le débourrage des pièces. Différents modes de chargements mécaniques ont été étudiés : flexion, compression, cisaillement, push-out, fatigue, fluage ou encore compression œdométrique. Ils correspondent à différents types de sollicitations, avec ou sans confinement du noyau, et permettent de caractériser soit le cœur ou la surface du matériau. L’endommagement peut être suivi grâce à la réalisation de cycles de décharge-recharge. Dans tous les cas, le comportement mécanique du noyau est fortement dépendant des propriétés et de l’état du liant. Ainsi, la dégradation thermique induite par la coulée de l’aluminium liquide modifie et dégrade nettement les propriétés du noyau. Des parallèles peuvent ainsi être dressés entre les propriétés du liant, le comportement mécanique du matériau sable/résine et l’endommagement microstructural observé après rupture. / Better knowledge about the mechanical behavior of foundry sand cores is required in order to optimize the aluminum cylinder head production process. Sand cores allow the casting of complex shape metallic parts and are made of sand grains, bound with a resin in low proportion. Sand cores are subjected to high temperatures and complex mechanical load during the production process. This study aims at characterizing the thermomechanical behavior of sand cores under various loads depending on the binder proportion, the temperature and mostly the binder thermal degradation. Particularly, we focus on the cores damage and fracture mechanisms. The understanding of such phenomena could lead to an optimization of the decoring step, consisting in the fracture and removing of the core from the metallic part. Indeed, the results of this Ph.D. thesis will be used to implement a numerical model of the decoring process. Different kinds of mechanical loads have been studied: bending, compression, shear, push-out, fatigue, creep or also oedometric tests. They correspond to different kinds of load, with or without confining pressure and allow a characterization of the bulk or the surface of the material. The core damage is followed by mechanical tests with unload-reload cycles sequences. For all the cases, the core mechanical behavior is highly dependent on the binder properties and thermal degradation. For example, the thermal degradation induced by the aluminum casting modifies and degrades significantly the core properties. Analogies could be drawn between the binder properties, bonded-sand cores mechanical behavior and the evolution of the fracture surfaces.

<p>Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. This is the case for the explosive magnetic flux compression generator (EMG) and a ferromagnetic actuator. </p><p>Models are presented that are mainly intended for transients in the millisecond range and faster. Hence, eddy currents and the related skin and proximity effect become significant in windings, magnetic cores and in the armatures of the devices. These effects are important for, e.g., the damping of the transients. Further, the displacement current in the insulation of the winding is significant. It changes the response of the windings dramatically, as it manifests the finite velocity of propagation of the electromagnetic fields. Under such circumstances, reflections and excited resonances can make the transient voltage and current distribution highly irregular. </p><p>Induced voltages are modelled with self and mutual inductances or reluctances combined with winding templates. The displacement currents are modelled with capacitances or coefficients of potential. Cauer circuits and their dual form are used to model eddy currents in laminated cores and in conductors. The Cauer circuit enables one to consider hysteresis and the non-linear response of a magnetic core. It is also used to model the eddy currents in the moving armature of an EMG. </p><p>A set-up is presented that can be used to study the transient voltage and the current distribution along a coil. </p><p>The transient response of coaxially insulated windings is analysed and modelled in detail. A lumped circuit model is developed for a coil, Dryformer^TM - the new high-voltage transformer - and Powerformer^TM, the new high-voltage generator. An alternative model, a combined lumped circuit and FEM model, is presented for a coaxially insulated winding in two slot cores.</p>

Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. This is the case for the explosive magnetic flux compression generator (EMG) and a ferromagnetic actuator. Models are presented that are mainly intended for transients in the millisecond range and faster. Hence, eddy currents and the related skin and proximity effect become significant in windings, magnetic cores and in the armatures of the devices. These effects are important for, e.g., the damping of the transients. Further, the displacement current in the insulation of the winding is significant. It changes the response of the windings dramatically, as it manifests the finite velocity of propagation of the electromagnetic fields. Under such circumstances, reflections and excited resonances can make the transient voltage and current distribution highly irregular. Induced voltages are modelled with self and mutual inductances or reluctances combined with winding templates. The displacement currents are modelled with capacitances or coefficients of potential. Cauer circuits and their dual form are used to model eddy currents in laminated cores and in conductors. The Cauer circuit enables one to consider hysteresis and the non-linear response of a magnetic core. It is also used to model the eddy currents in the moving armature of an EMG. A set-up is presented that can be used to study the transient voltage and the current distribution along a coil. The transient response of coaxially insulated windings is analysed and modelled in detail. A lumped circuit model is developed for a coil, DryformerTM - the new high-voltage transformer - and PowerformerTM, the new high-voltage generator. An alternative model, a combined lumped circuit and FEM model, is presented for a coaxially insulated winding in two slot cores.