984 resultados para Curve of accumulation
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Barium stars are optimal sites for studying the correlations between the neutron-capture elements and other species that may be depleted or enhanced, because they act as neutron seeds or poisons during the operation of the s-process. These data are necessary to help constrain the modeling of the neutron-capture paths and explain the s-process abundance curve of the solar system. Chemical abundances for a large number of barium stars with different degrees of s-process excesses, masses, metallicities, and evolutionary states are a crucial step towards this goal. We present abundances of Mn, Cu, Zn, and various light and heavy elements for a sample of barium and normal giant stars, and present correlations between abundances contributed to different degrees by the weak-s, mains, and r-processes of neutron capture, between Fe-peak elements and heavy elements. Data from the literature are also considered in order to better study the abundance pattern of peculiar stars. The stellar spectra were observed with FEROS/ESO. The stellar atmospheric parameters of the eight barium giant stars and six normal giants that we analyzed lie in the range 4300 < T(eff)/K < 5300, -0.7 < [Fe/H] <= 0.12 and 1.5 <= log g < 2.9. Carbon and nitrogen abundances were derived by spectral synthesis of the molecular bands of C(2), CH, and CN. For all other elements we used the atomic lines to perform the spectral synthesis. A very large scatter was found mainly for the Mn abundances when data from the literature were considered. We found that [Zn/Fe] correlates well with the heavy element excesses, its abundance clearly increasing as the heavy element excesses increase, a trend not shown by the [Cu/Fe] and [Mn/Fe] ratios. Also, the ratios involving Mn, Cu, and Zn and heavy elements usually show an increasing trend toward higher metallicities. Our results suggest that a larger fraction of the Zn synthesis than of Cu is owed to massive stars, and that the contribution of the main-s process to the synthesis of both elements is small. We also conclude that Mn is mostly synthesized by SN Ia, and that a non-negligible fraction of the synthesis of Mn, Cu, and Zn is owed to the weak s-process.
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The aim of this paper was to study a method based on gas production technique to measure the biological effects of tannins on rumen fermentation. Six feeds were used as fermentation substrates in a semi-automated gas method: feed A - aroeira (Astronium urundeuva); feed B - jurema preta (Mimosa hostilis), feed C - sorghum grains (Sorghum bicolor); feed D - Tifton-85 (Cynodon sp.); and two others prepared mixing 450 g sorghum leaves, 450 g concentrate (maize and soybean meal) and 100 g either of acacia (Acacia mearnsii) tannin extract (feed E) or quebracho (Schinopsis lorentzii) tannin extract (feed F) per kg (w:w). Three assays were carried out to standardize the bioassay for tannins. The first assay compared two binding agents (polyethylene glycol - PEG - and polyvinyl polypirrolidone - PVPP) to attenuate the tannin effects. The complex formed by PEG and tannins showed to be more stable than PVPP and tannins. Then, in the second assay, PEG was used as binding agent, and this assay was done to evaluate levels of PEG (0, 500, 750, 1000 and 1250 mg/g DM) to minimize the tannin effect. All the tested levels of PEG produced a response to evaluate tannin effects but the best response was for dose of 1000 mg/g DM. Using this dose of PEG, the final assay was carried out to test three compounds (tannic acid, quebracho extract and acacia extract) to establish a curve of biological equivalent effect of tannins. For this, five levels of each compound were added to I g of a standard feed (Lucerne hay). The equivalent effect showed not to be directly related to the chemical analysis for tannins. It was shown that different sources of tannins had different activities or reactivities. The curves of biological equivalence can provide information about tannin reactivity and its use seems to be important as an additional factor for chemical analysis. (C) 2007 Elsevier B.V. All rights reserved.
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A procedure is proposed for the determination of the residence time distribution (RTD) of curved tubes taking into account the non-ideal detection of the tracer. The procedure was applied to two holding tubes used for milk pasteurization in laboratory scale. Experimental data was obtained using an ionic tracer. The signal distortion caused by the detection system was considerable because of the short residence time. Four RTD models, namely axial dispersion, extended tanks in series, generalized convection and PER + CSTR association, were adjusted after convolution with the E-curve of the detection system. The generalized convection model provided the best fit because it could better represent the tail on the tracer concentration curve that is Caused by the laminar velocity profile and the recirculation regions. Adjusted model parameters were well cot-related with the now rate. (C) 2010 Elsevier Ltd. All rights reserved.
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The aim of this study was to validate an agar diffusion method through the parameters linearity, precision and accuracy, to quantify apramycin in soluble powder. The calibration curve of apramycin was constructed by plotting log of concentrations (mu g ml(-1)) versus zone diameter (mm) and shows good linearity in the range of 1.0-4.0 mu g.ml(-1). The precision of the assay was determined by assaying samples at the same day (repeatability - R.S.D. = 2.00%) and on different days (intermediate precision - R.S.D. = 5.06%) and indicate good precision. The accuracy expresses the agreement between the accepted value and the value found. The mean recovery was found to be 100.49 % for apramycin soluble powder. The results indicated that the microbiological assay proposed in this work hold linearity, precision and accuracy being an acceptable alternative method for routine quality control of apramycin in the pharmaceutical dosage form studied.
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GUALANO, B., V. DE. SALLES PAINNELI, H. ROSCHEL, G. G. ARTIOLI, M. NEVES JR, A. L. DE SA PINTO, M. E. DA SILVA, M. R. CUNHA, M. C. G. OTADUY, C. DA COSTA LEITE, J. C. FERREIRA, R. M. PEREIRA, P. C. BRUM, E. BONFA, and A. H. LANCHA JR. Creatine in Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Trial. Med. Sci. Sports Exerc., Vol. 43, No. 5, pp. 770-778, 2011. Creatine supplementation improves glucose tolerance in healthy subjects. Purposes: The aim was to investigate whether creatine supplementation has a beneficial effect on glycemic control of type 2 diabetic patients undergoing exercise training. Methods: A 12-wk randomized, double-blind, placebo-controlled trial was performed. The patients were allocated to receive either creatine (CR) (5 g.d(-1)) or placebo (PL) and were enrolled in an exercise training program. The primary outcome was glycosylated hemoglobin (Hb(A1c)). Secondary outcomes included the area under the curve of glucose, insulin, and C-peptide and insulin sensitivity indexes. Physical capacity, lipid profile, and GLUT-4 protein expression and translocation were also assessed. Results: Twenty-five subjects were analyzed (CR: n = 13; PL: n = 12). Hb(A1c) was significantly reduced in the creatine group when compared with the placebo group (CR: PRE = 7.4 +/- 0.7, POST = 6.4 +/- 0.4; PL: PRE = 7.5 +/- 0.6, POST = 7.6 +/- 0.7; P = 0.004; difference = -1.1%, 95% confidence interval = -1.9% to -0.4%). The delta area under the curve of glucose concentration was significantly lower in the CR group than in the PL group (CR = -7790 +/- 4600, PL = 2008 +/- 7614; P = 0.05). The CR group also presented decreased glycemia at times 0, 30, and 60 min during a meal tolerance test and increased GLUT-4 translocation. Insulin and C-peptide concentrations, surrogates of insulin sensitivity, physical capacity, lipid profile, and adverse effects were comparable between the groups. Conclusions: Creatine supplementation combined with an exercise program improves glycemic control in type 2 diabetic patients. The underlying mechanism seems to be related to an increase in GLUT-4 recruitment to the sarcolemma.
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Aim: To compare cervical length (CL) at 18-21 and 22-25 weeks` gestation in twin pregnancies in prediction of spontaneous preterm delivery and to examine cervical shortening. Methods: Retrospective cohort study of CL measured at 18-21 and 22-25 weeks` gestation in twin pregnancies. Results: Receiver operating characteristics (ROC) curve revealed area of 0.64 (95% CI 0.53-0.75) and 0.80 (95% CI 0.72-0.88) for measurements at 18-21 and 22-25 weeks, respectively (P <= 0.001). Sensitivities of 33.3% and 23% and negative predicting value (NPV) of 97.3% and 86.8% for delivery at <28 and <34 weeks gestation were reached for measurements at 18-21 weeks. Sensitivities of 71.4% and 38.2% and NPV of 99.1% and 91.4% for delivery at <28 and <34 weeks` gestation were reached for measurements at 22-25 weeks. Cervical length shortening analysis showed an area under ROC curve of 0.81 (95% CI 0.73-0.89) and best cut-off was at >= 2 mm/week. Sensitivities of 80% and 60.8% and NPV of 98.9% and 90.6% for delivery at <28 and <34 weeks gestation were reached. Conclusions: In twin gestations, assessment of CL at 22-25 weeks is better than assessment at 18-21 weeks to predict preterm delivery before 34 weeks. Cervical shortening at a rate of >= 2 mm/weeks between 18 and 25 weeks gestation was a good predictor of spontaneous preterm birth in this high-risk population.
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Background Chronic progressive external ophthalmoplegia is a mitochondrial myopathy that causes muscular or multisystem symptoms and has dysphagia as one manifestation. Aim To evaluate esophageal contractions in patients with chronic progressive external ophthalmoplegia. Methods We studied 14 patients with chronic progressive external ophthalmoplegia and 16 asymptomatic volunteers. The diagnosis of the disease was established by the clinical picture and by mitochondrial DNA analysis in skeletal muscle. We used the manometric method with a perfusion catheter that recorded the esophageal contractions at 2, 7, 12, 17, and 22 cm from the lower esophageal sphincter (LES). All subjects performed in the supine position 20 swallows of a 5-ml bolus of water at room temperature, ten every 30 s and ten every 10 s. Results The amplitude, duration, and area under the curve of contractions at 17 and 22 cm from the LES were lower in patients than in volunteers for swallows performed at 10-s and 30-s intervals (P < 0.01). There was no difference in contractions at 7 and 2 cm, except for the contractions at 2 cm after swallows performed at 30-s intervals. The interval between the onset of contractions between 7 and 2 cm and between 22 and 2 cm was lower in patients than in volunteers, with swallows performed every 10 s and every 30 s. Conclusions There is impairment of esophageal contractions in patients with chronic progressive external ophthalmoplegia, mainly in the proximal esophageal body.
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A partir de uma análise detalhada do processo de infiltração de água no solo, foram propostas alternativas para adequação dos parâmetros de entrada do modelo de Green-Ampt-Mein-Larson (GAML), na tentativa de melhorar a eficiência da estimativa da infiltração em alguns solos brasileiros. As adequações consistiram em substituir a condutividade hidráulica do solo saturado (K0) pela taxa de infiltração estável (Tie) e o teor de água do solo saturado (qs) pelo teor de água na zona de transmissão (qw), além de estabelecer uma equação para estimativa do potencial matricial na frente de umedecimento (yf) com base nos parâmetros do modelo de curva de retenção de água de Brooks & Corey. Avaliou-se o desempenho do conjunto de adequações propostas (GAML-t) para estimativa da infiltração de água em três solos: Latossolo Vermelho-Amarelo, Latossolo Vermelho e Argissolo Vermelho. O desempenho do GAML-t foi comparado com o obtido pelo GAML aplicado em sua forma original e adequado segundo cinco diferentes formas, evidenciando-se que o primeiro obteve melhor desempenho nos três solos estudados.
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Partimos do fato de que, nas últimas décadas, em especial a partir da década de 1980, o capital retoma parte da lucratividade perdida na década anterior. Essa retomada da lucratividade, contudo, se dá sobre características fortemente diferenciadas da acumulação que marcou o crescimento do período conhecido como os “30 anos dourados” do capitalismo (sobretudo para a perspectiva das classes dominantes dos países centrais). Nesse sentido, nosso pressuposto é que, desde a virada operada pela crise estrutural da década de 1970, a esfera financeira ganhou autonomia em relação ao ciclo global da reprodução capitalista. E, decorrente dessa autonomia, a esfera financeira salta à condição de dominância em relação ao ciclo global. Assim, o objetivo geral desta dissertação é analisar os trabalhos que, pela perspectiva crítica, têm como objeto a esfera financeira. E nosso objetivo específico é compreender como a esfera financeira se relaciona com o ciclo global da reprodução capitalista. Dessa forma, quais seriam as principais características deste novo momento? Quais as causas que teriam impulsionado um crescimento tão acelerado da esfera financeira? Se vivemos em uma fase do capitalismo com forte influência financeira, em que consiste a financeirização, termo que aqui adotamos? E, principalmente, qual o seu relacionamento com o ciclo global do capital? Ela contribuiu para o desenvolvimento da acumulação capitalista ou pode ser considerada como refratária ao desenvolvimento e à expansão do capitalismo? Estas serão as questões que serão trabalhadas ao longo da dissertação.
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Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em hidráulica
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A verificação das Características Garantidas associadas aos equipamentos, em especial dos aerogeradores, incluídos no fornecimento de Parques Eólicos, reveste-se de particular importância devido, principalmente, ao grande volume de investimento em jogo, ao longo período necessário ao retorno do mesmo, à incerteza quanto à manutenção futura das actuais condições de remuneração da energia eléctrica produzida e ainda à falta de dados históricos sobre o período de vida útil esperado para os aerogeradores. Em face do exposto, é usual serem exigidas aos fornecedores, garantias do bom desempenho dos equipamentos, associadas a eventuais penalidades, quer para o período de garantia, quer para o restante período de vida útil, de modo a minimizar o risco associado ao investimento. No fornecimento de Parques Eólicos existem usualmente três tipos de garantias, nomeadamente, garantia de Curva de Potência dos aerogeradores, garantia de Disponibilidade dos equipamentos ou garantia de Produção de Energia. Estas poderão existir isoladamente ou em combinação, dependendo das condições contratuais acordadas entre o Adjudicatário e o Fornecedor. O grau de complexidade e/ou trabalho na implementação das mesmas é variável, não sendo possível afirmar qual delas é a mais conveniente para o Adjudicatário, nem qual a mais exacta em termos de resultados. Estas dúvidas surgem em consequência das dificuldades inerentes à recolha dos próprios dados e também da relativamente ampla margem de rearranjo dos resultados permitido pelas normas existentes, possibilitando a introdução de certo tipo de manipulações nos dados (rejeições e correlações), as quais podem afectar de forma considerável as incertezas dos resultados finais dos ensaios. Este trabalho, consistiu no desenvolvimento, execução, ensaio e implementação de uma ferramenta informática capaz de detectar de uma forma simples e expedita eventuais desvios à capacidade de produção esperada para os aerogeradores, em função do recurso verificado num dado período. Pretende ser uma ferramenta manuseável por qualquer operador de supervisão, com utilização para efeitos de reparações e correcção de defeitos, não constituindo contudo uma alternativa a outros processos abrangidos por normas, no caso de aplicação de penalidades. Para o seu funcionamento, são utilizados os dados mensais recolhidos pela torre meteorológica permanente instalada no parque e os dados de funcionamento dos aerogeradores, recolhidos pelo sistema SCADA. Estes são recolhidos remotamente sob a forma de tabelas e colocados numa directoria própria, na qual serão posteriormente lidos pela ferramenta.
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes
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Mestrado em Engenharia Geotécnica e Geoambiente
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OBJECTIVE: To assess intermediate-term outcome in children who have undergone orthotopic heart transplantation. METHODS: We carried out a longitudinal and prospective study between October '92 and June '99 comprising 20 patients with ages ranging from 12 days to 7 years (mean of 2.8 years). We employed a double immunosuppression protocol with cyclosporine and azathioprine and induction therapy with polyclonal antithymocyte serum. Survival and complications resulting from the immunosuppression protocol were analyzed. RESULTS:The double immunosuppression protocol and the induction therapy with polyclonal antithymocyte serum resulted in an actuarial survival curve of 90% and 78.2% at 1 and 6 years, respectively, with a mean follow-up period of 3.6 years. One patient died due to acute rejection 40 days after transplantation; another patient died 2 years after transplantation due to lymphoproliferative disorder; a third patient died because of primary failure of the graft; and a fourth patient died due to bronchopneumonia. The major complications were as follows: acute rejection, infection, nephrotoxicity, and systemic hypertension. The means of rejection and infection episodes per patient were 2.9 and 3.4, respectively. After one year of transplantation, a slight reduction in the creatinine clearance and systemic hypertension were observed in 7 (38.9%) patients. CONCLUSION: Heart transplantation made life possible for those patients with complex congenital heart diseases and cardiomyopathies in refractory congestive heart failure constituting a therapeutical option for this group of patients in the terminal phase.
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In this paper, preliminary to a series of investigations that the A. has the purpose to make about the influence of climatic factors particularly upon the prevalence of the most important acute infectious diseases in Brazil, he raises the question whether such factors do affect in this country the total death rates, as it is reasonable to suppose, according to what has been observed in temperate zones of northern and southern hemispheres. The inclusion of absolute humidity among other climatic factors to be dealt with seems justifiable according to Rogers and Stallybrass. Owing to scarcety of reliable data the A. was obliged to limit to a five-years period (1940-1944) the complete proposed investigation, which includes seven of the most important cities, scattered throughout the brazilian territory, from north to south - Belém, recife, Salvador, Rio, S. Paulo, Curitiba and Porto Alegre. Reference is made to their normal climatic conditions and monthly death-rates variations with their mean values and standard deviations. In a first part dealing with seasonal variations only for purposes of comparison, he points out that in there tropical cities of Brazil, without very clear seasonal differentiation, the curve of general mortality reached its highest point in austral autumn season and the remaining four (including Rio near the tropic) in the spring, with the exception of Curitiba, where the peak coincided with the summer season. He shows how such important causes of deaths, as diarrheas, common respiratory diseases and tuberculosis, whose seasonal distribution for each one of the seven cities is referred, may explain such seasonal variations. On a second part, a study is made of the general mortality distribution by four-months periods selected in accordance respectively with the highest or lowest values of rainfall and of mean temperature and humidity during period 1940-1944. Finally he compares the monthly waves of such climatic factors and the corresponding waves of total death - rates and finds through correlation coefficients 17 significant values with respect to their standard errors. Variations in the death - rates seemed to be perhaps more closely and uniformly associated with variations of mean humidity, as is indicated by coefficients ranging from + 0.3 to 0.6.