800 resultados para Ast-87093
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Pós-graduação em Medicina Veterinária - FCAV
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A Photocatalyst ceramic powder that presented high photoactivity based on TiO2 modified with 25% molar of SnO2 and up to 5% molar of Ag2O was obtained in the present work. The aforementioned ceramic powder was obtained using all commercial oxides as well as the oxides mixture technique. The powders were ground in high energy mill for one hour with subsequent thermal treatment at 400°C for four hours. They were, furthermore, characterized using surface area of around 6m2/g, where the X-Ray diffraction results provided evidence for the presence of anatase and rutile phases, known to be typical characteristics of both the TiO2 and SnO2 used. During the thermal treatment, Ag2O was reduced to metallic silver. The photodegradation rehearsals were carried out using a 0.01 mmol/L Rhodamine B solution in a 100mg/L photocatalyst suspension in a 500ml beaker, which was irradiated with 4W germicide Ultraviolet light of 254nm. In addition, samples were removed after duration of about 10 minutes to an hour, where they were analyzed thoroughly in UV-vis spectrophotometer. The analysis of the results indicated that for the compositions up to 2.5% molar of Ag2O, the photoactivity was found to be greater than that of Degussa P25 photocatalyst powder, and as such it was then used as a reference. Taking into account 90% degradation of Rhodamine B, a duration period of 11 minutes was obtained for the developed photocatalyst powder compared to the 38 minutes observed for the Degussa P25. FEG-SEM micrographies enabled the verification of the morphology as well as the interaction of the oxide particles with the metallic silver, which led us to propose a model for the increase in photoactivity observed in the photocatalyst powder under investigation.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Zootecnia - FCAV
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Introduction: The HELLP syndrome is a severe complication of pregnant women with preeclampsia (PE), characterized by association of hemolysis, changes in liver enzymes and thrombocytopenia. Hemolysis, defined by the presence of microangiopathic hemolytic anemia, is one of the characteristics in this syndrome. However, as hemolysis occurs in a short time there is some difficulty in its laboratory diagnosis. Therefore, the search for a more sensitive and specific method for hemolysis determination may help in the early diagnosis of the HELLP syndrome. Objectives: a) To determine the plasma concentration of haptoglobin in normotensive pregnant women and in pregnant women with PE, classified into mild PE, severe PE and HELLP/partial HELLP syndrome; b) To compare the efficacy of haptoglobin plasma concentration and serum total bilirubin as criteria for hemolysis diagnosis in HELLP/partial HELLP syndrome. Methods: We conducted a cross-sectional analytical and comparative study involving 66 pregnant women diagnosed with PE, being 25 cases with mild PE, 28 with severe PE, and 13 with HELLP/partial HELLP syndrome. Twenty-one normotensive pregnant women were included for comparison of haptoglobin plasma concentration between the groups and to determine the normal values for pregnant women. The variables studied were: maternal age, gestational age, systolic and diastolic blood pressure, proteinuria, hematocrit and hemoglobin values, platelet count, serum total bilirubin, lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (AST) and glutamic-pyruvic transaminase (ALT), urea, creatinine and uric acid, and also plasma concentrations of haptoglobin. The results were analyzed by nonparametric tests, with a significance level of 5%. Results: The values of urea, uric acid, AST, ALT and LDH were significantly higher, while the number of platelets was lower in pregnant women with HELLP/partial HELLP syndrome compared to pregnant women with mild PE and ...
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Pós-graduação em Ciência Animal - FMVA
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Pós-graduação em Ciência e Tecnologia Animal - FEIS
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Pós-graduação em Medicina Veterinária - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.
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We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50-550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 x 10(-24) and 8 x 10(-25) are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof-of-principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of similar to 1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.
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The Advanced LIGO gravitational wave detectors are second-generation instruments designed and built for the two LIGO observatories in Hanford, WA and Livingston, LA, USA. The two instruments are identical in design, and are specialized versions of a Michelson interferometer with 4 km long arms. As in Initial LIGO, Fabry-Perot cavities are used in the arms to increase the interaction time with a gravitational wave, and power recycling is used to increase the effective laser power. Signal recycling has been added in Advanced LIGO to improve the frequency response. In the most sensitive frequency region around 100 Hz, the design strain sensitivity is a factor of 10 better than Initial LIGO. In addition, the low frequency end of the sensitivity band is moved from 40 Hz down to 10 Hz. All interferometer components have been replaced with improved technologies to achieve this sensitivity gain. Much better seismic isolation and test mass suspensions are responsible for the gains at lower frequencies. Higher laser power, larger test masses and improved mirror coatings lead to the improved sensitivity at mid and high frequencies. Data collecting runs with these new instruments are planned to begin in mid-2015.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Introduction: skeletal muscles are dynamic tissue that can change their phenotypic characteristics providing a better functional adaptation to different stimuli. L-thyroxine is a hormone produced by the thyroid gland and has been used as an experimental model for stimulation of oxidative stress in skeletal muscle. Coenzyme Q10 (CoQ10) is a fat-soluble provitamin endogenously synthesized and found naturally in foods such red meat, fish, cereals, broccoli and spinach. It has antioxidant properties and potential in the treatment of degenerative and neuromuscular diseases. Objective: to evaluate the protective effect of CoQ10 in the soleus muscle of rats against the oxidative damage caused by L-thyroxine. Methods: the rats were divided in four groups of six animals each: Group 1 (control); Group 2 (coenzyme Q10); Group 3 (L-thyroxine), and Group 4 coenzyme Q10 and L-thyroxine). After euthanasia, blood was collected and serum activity of the enzymes creatine kinase (CK) and aspartate aminotransferase (AST) was analyzed. In the soleus muscle homogenates the factors related to oxidative stress were assessed. Results: CoQ10 protected the soleus muscle against the damage caused by L-thyroxine and favored the maintenance of the antioxidant enzymes glutathione reductase and glutathione peroxidase, the concentration of decreased and oxidized glutathione, and prevented lipid peroxidation. Conclusion: the results indicate that CoQ10 protects rat soleus muscle from oxidative damage caused by L-thyroxine.