769 resultados para Válvulas cardíacas
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The search for materials with higher properties and characteristics (wear resistance, oxidation, corrosion, etc.) has driven research of various materials. Among the materials that are being studied with such properties and characteristics are super alloys based on nickel which has an important role in the aeronautical, automotive, marine, production of gas turbines and now in space vehicles, rocket engineering , experimental aircraft, nuclear reactors, steam-powered plants, petrochemical and many other applications because besides having all the characteristics and properties mentioned above also have an excellent performance at high temperatures. The super alloy based on nickel studied in this work is the super alloy Pyromet 31v normally used in the manufacture of exhaust valves in common engines and diesel engines of high power by cater requirements such as mechanical strength and corrosion resistance at temperatures of approximately 815 ° C. The objective of this work is to produce results to demonstrate more specific information about the real influence of coatings on cutting tools and cutting fluids in turning and thus promote the optimization of the machining of these alloys. The super alloy Pyromet 31v was processed through turning, being performed with various machining parameters such as cutting speed, feed rate, depth in conditions of Minimum Amount of Fluid (MAF), abundant fluid, cutting tools with coating and without coating in early in his work life and with wear. After turning were obtained several samples of chips and the part generated during the machining process, was measured roughness of the material, subsequently made macrostructural analysis of the tools used order to detect possible wear and microstructural analysis of samples collected being that the latter was used for Optical Microscopy, Scanning Electron Microscopy (SEM) and ... (Complete abstract click electronic access below)
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A Organização Mundial de Saúde estima que existem cerca de 10 milhões de infectados pelo Trypanosoma cruzi, 30% dos infectados cronicamente desenvolvem alterações cardíacas, e 10% digestivas e neurológicas. O T. cruzi é um protozoário cinetoplástida flagelado agente etiológico da tripanossomíase americana, popularmente conhecida como a Doença de Chagas, uma antropozoonose conhecida na América Latina. Pelo menos 40 espécies de triatomíneos – conhecido por barbeiros – carregam o protozoário. O gênero Triatoma representa o principal vetor da Doença de Chagas e são adaptados a climas secos de ambientes rurais da América do Sul e Central. Outras formas de infecção podem ocorrer por transfusão de sangue, transplantes, via oral, e transmissão vertical. Há duas fases que caracterizam a infecção pelo T. cruzi: a fase aguda, apresentando um período de incubação de uma semana a um mês, que geralmente é assintomática. Já a fase crônica é mais polêmica e divide a opinião dos pesquisadores, mas basicamente mostra-se como uma cardiomiopatia chagásica, ou uma dilatação no trato digestivo e ainda pode causar lesões no sistema nervoso parassimpático e simpático. Entre essas duas fases ocorre um período indeterminado em que não há nenhuma manifestação clínica da doença. Existem teorias que explicam a patogenicidade das lesões da doença: uma postula que as lesões características da Chagas são referentes à ruptura das células parasitadas e subsequente inflamação. Outra é a teoria da autoimunidade, em que o próprio sistema imune do indivíduo rejeita as células livres de parasitas causando as lesões características da doença. Há evidências substanciais que comprovem a participação das respostas imunes nas lesões miocárdicas, mas como o parasito consegue desencadear estas respostas imunes, ainda não está esclarecido... (Resumo completo, clicar acesso eletrônico abaixo)
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Aortic regurgitation (AR) leads to a left ventricle dilation and hypertrophy in response to a chronic volume overload. It is still very frequent in developing countries, for instance Brazil, and often as secondary to rheumatic fever. Usually, chronic AR is generally well tolerated for many years, when with the heart dilated the patient searches for treatment. Bidirectional association with depression and cardiovascular disease has been described. Selective serotonin reuptake inhibitors (SSRI) are widely prescribed to treat several affective disorders, especially for cardiovascular patients since they decrease arrhythmia probability. These SSRI improves cardiac function in rats submitted to stress protocols. Preliminary study from our laboratory showed that following 4 weeks of treatment with one SSRI (paroxetine) in subchronic AR rats there was a decreased in daily sodium intake and an improvement in systolic function. An increase in the central oxytocinergic transmission may be involved in this peripheral improvement to the heart. The investigations about the mechanisms underlying this improvement are necessary. Therefore the aims of this project is investigate the effects of 4 weeks of treatment of paroxetine, a SSRI, in rats with a subchronic AR over the central central gene expression of oxytocin and vasopressin using a reverse transcription polymerase chain reaction (RT-PCR)
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Pressure drop and energy efficiency of compressors in chemical plants are the focus of this study. Its objective is an analysis of possible sources of energy loss through the study of pressure loss in pipes, calculation of thermodynamic efficiency of the compressors. Important issues are raised for this analysis such as the types of compressors, the operating range of each compressor, compression types, as well as a study of accessories such as filters and valves. After studying these issues was carried out calculations of pressure drop step-bystep and with a software WIPCD. Followed by the calculation of efficiency of compressors and monthly energy cost of each compressor in operation. Finally, the study shows some suggestions for immediate improvements, changes and suggestions for possible future purchases of compressors
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Maternal smoking during pregnancy causes heart changes, impaired fetal growth, spontaneous abortion and low birth weight. Even in pregnant women exposed to cigarette smoke these changes can be observed. But the exercise is to answer the increased fetal weight, besides the improvement of cardiorespiratory fitness of the pregnant and the fetus. The objective of this study was to analyze the ventricular muscle of young rats subjected to passive smoking associated with aquatic exercise. For the experiments used 24 female rats were divided into: GC (control), GE (exercise protocol in the water), GF(exposed to cigarette smoke) and GEF (exercise protocol on water and exposed to cigarette smoke). On the same day was held the 1st session of the experimental phase of the protocol of exposure to cigarette smoke, which consisted of 30 minutes twice a day, six days a week for three weeks, followed by the first session of the swimming program... (Complete abstract click electronic access below)
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Pós-graduação em Medicina Veterinária - FCAV
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This work studies the most commonly used methods and make comparisons and discussions of the findings made by each of them and the results provided by them. The objective of this research was to show that the method of characteristics is currently the most efficient method to perform these simulations because of its broad scope low simplifications, requirement allowing to consider every detail of the pipe and fluid. Manual calculations are performed and also a software capable of calculating this phenomenon for various situations, such as water pump, elevated tanks, valves and quick maneuver was developed. The software is based on the method of characteristics that is currently recommended by ABNT. These methods, and the results are obtained numerically and graphically are adopted pipes and amount of downstream conditions and in which will be applied. The conclusions reached showed that the Allievi method is widely used yet because of its efficiency and quick calculation for simple pipes. The method of characteristics, although a lot of work to be calculated due to the calculation is iterative process and requires a program to use it, is the only one that allows the calculation with all amount to the conditions situations and downstream of all the pipe possibilities found
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Fisiopatologia em Clínica Médica - FMB
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Pós-graduação em Fisiopatologia em Clínica Médica - FMB
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Fisiopatologia em Clínica Médica - FMB
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The aim of this study was to review the prevalence of canine splenic disorders by means of a retrospectiveanalysis of histological diagnosis after splenectomy. The results were confronted with laboratory findings, clinical signs and presence of cardiac arrhythmia and hemoperitoneum, in an attempt to establish the differentialdiagnosis of splenomegaly. One hundred and nine dogs assisted at the Veterinary Hospital of theSchool of Veterinary Medicine and Zootechny, University of São Paulo, were included in the retrospectivestudy, between 2002 and 2009. The average age was 10 years old ± 3, with no sexual predilection. Mixedbreed dogs was the most affected kind, and average weight was 22 kg ± 13. Overall, 52% (57/109) of dogswere splenectomized due to non-neoplastic diseases and 48% (52/109) to neoplastic diseases. Among thelatter, the most common diagnosis was hemangiosarcoma (28 dogs; 54%). Most frequent clinical signs includedanorexia, lethargy and vomiting. Results showed that dogs with low red blood cell count, low hematocritvalues and/or hemoperitoneum were more likely to have splenic malignant neoplasm. On the otherhand, sex, breed, size, age, cardiac arrhythmia and other laboratory parameters were not determining factorsin the differentiation of splenomegaly.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Medicina Veterinária - FCAV