Made available in DSpace on 2014-10-09T12:32:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:29Z (GMT). No. of bitstreams: 1 01537.pdf: 1505528 bytes, checksum: 79b06b0cf173671eeb859566744153c3 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:32:27Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:15Z (GMT). No. of bitstreams: 1 03181.pdf: 1949463 bytes, checksum: c34e1f3d7f43777cbd9147685ab2ea6e (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Orientador: Paulo do Nascimento Júnior / Banca: Norma Sueli Pinheiro Modolo / Banca: Rosa Inês Costa Pereira / Banca: Irimar de Paula Presso / Banca: Luiz Vicente Garcia / Resumo: A dexmedetomidina (Dex) tem efeito de simpatolise no sistema nervoso central e de inibicao da neurotransmissao nos nervos simpaticos. Assim, a Dex poderia suprimir o estado hiperdinamico do sistema cardiocirculatorio que ocorre durante a cirurgia da aorta. Em modelo de pincamento infra-renal da aorta (Aox) em caes sob anestesia com o sevoflurano, estudaram-se os efeitos cardiovasculares e de oxigenacao sistemica da Dex. Trinta caes foram submetidos a anestesia com sevoflurano, empregando-se 0,75 da concentracao alveolar minima (CAM) do halogenado, ventilados artificialmente e submetidos a Aox e despincamento aortico (DAox). Os animais foram distribuidos aleatoriamente e de modo encoberto em tres grupos: Placebo: (n=10) . infusao de solucao salina; Dex 1 (n=10) . infusao de Dex (1 Êg.kg-1), em 10 minutos, seguida por infusao continua de Dex (1 Êg.kg-1.h-1); e Dex 2 (n=10) - infusao de Dex (2 Êg.kg-1), em 10 minutos, seguida por infusao continua de Dex (2 Êg.kg-1.h-1). Os atributos hemodinamicos e de oxigenacao sistemica foram estudados nos momentos controle, apos a infusao das solucoes, apos 20 e 40 minutos do Aox e apos 20 e 40 minutos do DAox. A Dex diminuiu a frequencia cardiaca (FC) e o indice cardiaco. Na vigencia do Aox, o IC e a FC, nos grupos da Dex, foram menores do que no grupo Placebo (p < 0,05). Em Dex 1 e Dex 2, a pressao arterial media (PAM) apresentou valores mais elevados do que os do Placebo, enquanto a pressao de oclusao da arteria pulmonar (POAP) e o indice de resistencia vascular sistemica (IRVS) aumentaram de maneira INTRODUCAO E LITERATURA 9 dosedependente (p < 0,05). Nos grupos da Dex, o indice de transporte de oxigenio (ITO2) foi menor do que no grupo Placebo, enquanto a saturacao de oxigenio do sangue venoso misto foi menor em Dex 2 em relacao aos demais grupos (p < 0,05). / Abstract: Dexmedetomidine (Dex) causes a centrally mediated sympatholysis and an inhibition of neurotransmission in sympathetic nerves. Thus, Dex could suppress the circulatory hyperdynamic state which accompanies aortic surgery. We studied the effects of Dex on hemodynamics and systemic oxygenation before, during and after infra-renal aortic cross-clamping (Aox). Thirty dogs were randomly assigned to three different general anesthetic regimens prior to Aox and unclamping (UAox). Group 1 (n=10), control, received 0.75 MAC sevoflurane plus saline infusion. Group 2 (n=10), Dex 1, received 0.75 MAC sevoflurane plus Dex (1 g.kg-1 load) followed by 1 g.kg-1.h-1 infusion. Group 3, Dex 2, received 0.75 MAC sevoflurane plus Dex (2 g.kg-1 load) followed by 2 g.kg-1.h-1 infusion. Hemodynamic and oxygenation variables were measured at baseline, after saline or Dex loading dose, and 20 and 40 min after Aox, and 20 and 40 min after UAox. Cardiac index and heart rate significantly decreased in Dex groups before Aox. Mean arterial pressure after Aox was higher in Dex groups than in Control (P<0.05) while pulmonary artery occlusion pressure and systemic vascular resistance were dose-dependently increased (P<0.05). Systemic oxygen delivery and mixed venous oxygen saturation was lower in Dex 2 compared to control (P<0.05). UAox had little effect on hemodynamics or oxygenation for control and Dex 1, however, Dex 2 was associated with a higher oxygen extraction ratio (P<0.05). In conclusion, Dex deleteriously altered hemodynamic and oxygenation effects of sevoflurane during Aox. INTRODUÇÃO E LITERATURA 11 These effects might limit the use of Dex in association with sevoflurane during aortic surgery. / Doutor

The impact of thermal stress on psychological performance has been the subject of considerable research attention. However, the effects of heat on performance are poorly understood. The literature yields inconsistent results, reflecting methodological shortcomings in previous research, particularly with regard to the definition of the independent variable. Investigators have focused on heat stress per se to the neglect of the participants' thermal physiological response. In addition, investigators have typically tested small samples, and have relied on a limited range of performance measures of unknown sensitivity. Few theoretical accounts of performance during thermal stress have been proposed, and these are poorly elaborated. The principal aim of this research programme was to elucidate the effects of heat on psychological performance. Emphasis was placed on defining the independent variable in terms of physiological strain. Performance was measured using a comprehensive range of sensitive tasks. In the first and second experiments, an innovative water immersion technique was used to control thermal strain precisely. The principal effect of heat strain observed in these experiments was an increase in the speed of performance, without variation in accuracy. This effect was attributed to an increase in nerve conduction velocity associated with raised body temperature. The duration of immersion in the second experiment was fifty percent longer than that in the first, but little variation in performance with the duration of heat strain was evident. In light of the limited external validity of the immersion experiments, subsequent investigation focused on the effects of more realistic sources of thermal strain. A survey of military personnel indicated that occupational exposure to thermal stress is perceived to impair some cognitive and psychomotor functions. The final experiment measured performance during prolonged exposure to heat stress in a climatic chamber. The results indicate that the performance changes observed in the immersion experiments generalize to conditions involving exposure to more realistic sources of heat strain

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Made available in DSpace on 2014-10-09T12:31:22Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:02Z (GMT). No. of bitstreams: 1 01379.pdf: 2229205 bytes, checksum: 03d1af6b550120be1df24a0326f85b7a (MD5) / Dissertacao(Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:49:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:58Z (GMT). No. of bitstreams: 1 10382.pdf: 2748014 bytes, checksum: abae13684ec54f32e7a024de8f8bb50f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:33:09Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:17Z (GMT). No. of bitstreams: 0 / O amido de bananas tem sido pesquisado na área de nutrição a partir da introdução do conceito de Amido Resistente (AR). O amido de Musa AAA-Nanicão e Musa AAB-Terra já foram caracterizados quanto as suas respostas fisiológicas. A banana verde possui boa quantidade de amido resistente. O principal interesse em relação ao amido resistente é o seu papel fisiológico. Por não ser digerido no intestino delgado, este tipo de amido se torna disponível como substrato para fermentação pelas bactérias anaeróbicas do cólon Dessa forma, essa fração compartilha muitas das características e benefícios atribuídos à fibra alimentar no trato gastrintestinal. O processo de irradiação por radiação gama pode causar uma variedade de modificações nas macromoléculas, algumas de aplicação industrial, como é o caso de perda de viscosidade e alteração de textura. No presente trabalho, farinhas de banana verde (FBV) de duas origens, foram utilizadas para estudar a sensibilidade a radiação por meio de medidas de viscosidade, textura, colorimetria e pH. As amostras de farinha de banana verde foram irradiadas com raios gama em doses de 0 a 10 kGy e taxa de dose em torno de 2kGy/h. As soluções de FBV apresentaram-se como fluidos não-newtonianos, A irradiação não alterou significativamente o pH dos hidrogéis das farinhas de banana verde FBV1 e FBV2. A viscosidade, de maneira geral, diminuiu com a dose de radiação aplicada. Quando analisada a textura a força máxima de ruptura dos hidrogéis de FBV1 e FBV2 decresceu conforme aumento da dose de irradiação. Entretanto, em particular quando irradiada a dose de 3 kGy, a FBV2 apresentou força de ruptura aumentada. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:32:38Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:10Z (GMT). No. of bitstreams: 1 03268.pdf: 1411071 bytes, checksum: 329c08d164e3d0d4d2a4ce77f1e2aa13 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:32:27Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:15Z (GMT). No. of bitstreams: 1 03181.pdf: 1949463 bytes, checksum: c34e1f3d7f43777cbd9147685ab2ea6e (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP