993 resultados para Amorim


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Infrared-to-visible upconversion luminescence emission in Nd3+-doped 60TeO(2)-10GeO(2)-10K(2)O-10Li(2)O-10Nb(2)O(5) tellurite glasses under cw excitation around 800 nm is investigated. Blue (430, and 475 nm), green (5 0 nm) and yellow-orange (590 nm) energy upconversion emission owing to the P-2(1/2) --> I-4(j) (j=9/2, 11/2, 13/2 and 15/2) transitions of the Nd3+ ions, respectively, was recorded. The dependence of the upconversion intensity upon the excitation wavelength and pump power is also studied. The upconversion excitation mechanism responsible for the observed emission signals is attributed to stepwise multiphoton absorption. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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We study the properties of the three-boson system with absorption, through a short range interaction in the limit where the range reduces to zero. We derive an analytic expression for the three-boson width that relates it to the real part of the three-boson energy, two-boson binding energy and decay constant. One of the characteristics of this expression is that, in this limit, the ratio between the width and the three-boson binding energy is proportional to the range.

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Buffalo meat production has been arising interest breeder and emerges as alternative to consumer, more and more demanding of the quality products. Thus, this research was conducted to study the chemical composition and tenderness of Longissimus dorsi muscle from 10 non-castrated Murrah buffaloes slaughtered at different weights. The research was carried in feedlot of School of Veterinary Medicine and Animal Science of the São Paulo State University, Botucatu, São Paulo, Brazil. Animals were divided in two groups, received diet ad libitum and slaughtered when reached 450 and 500 kg of live weight. The experiment design was completely randomized, with five repetitions to each treatment. Meat sample from Longissimus dorsi muscle, taken between 12(th) and 13(th) ribs, were carried analysis of moisture, crude protein, fat, ash, Longissimus muscle area (LMA), fat thickness (FT), marbling, calorie and tenderness. It did not have significant difference between the groups. Average values at of 76.0; 20.7; 2.1 and 1.2 of moisture, crude protein, fat and ash respectively, were obtained. Calorie, tenderness, LMA, FT and marbling were obtained at average values of 132 kca1/100g; 3.94 kgf; 34.2 cm(2); 5.9 mm and 2 points, respectively. Values obtained for tenderness are similar in the literature and has been proving that buffalo meat is tender (< 5kgf). Positive correlation was observed between the protein percentage and the shear force of the meat. The buffalo meat is excellent alternative source of red protein of high biological value to feeding of Brazilian consumers.

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Objective-To evaluate the effects of extracorporeal shock wave therapy (ESWT) on affected ligaments in the hind limbs of horses with experimentally induced suspensory ligament desmitis by use of ultrasonographic, ultrastructural, and immunocytochemical techniques.Animals-10 horses.Procedure-Suspensory ligament desmitis was induced in both hind limbs of each horse by use of 2 collagenase injections (administered 2 weeks apart) in each suspensory ligament. Two weeks after the second injection, the right hind limb of each horse was treated with ESWT (3 treatments at 3-week intervals)- the left hind limb was not treated (control limb). Periodically during the study, the healing process was monitored ultrasonographically and the proportions of ligaments affected with lesions were assessed. Four weeks after the last ESWT treatment, biopsy specimens were collected from all ligaments for ultrastructural evaluation and immunocytochemical analysis of transforming growth factor beta-1.Results-The difference in the proportion of the lesion-affected ligament between ESWT-treated and control limbs was significant (P < 0.05) from 3 weeks after the second ESWT treatment to the end of the study. Compared with control ligaments, ESWT-treated ligaments had more small, newly formed collagen fibrils and greater expression of transforming growth factor beta-1 4 weeks after the last ESWT treatment was administered.Conclusions and Clinical Relevance-Results have indicated that ESWT appears to facilitate the healing process in horses with experimentally induced hind limb suspensory ligament desmitis.

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Twenty eight Mediterranean buffaloes bulls were scanned with real-time ultrasound (RTU), slaughtered, and fabricated into retail cuts to determine the potential for ultrasound measures to predict carcass retail yield. Ultrasound measures of fat thickness, ribeye area and rump fat thickness were recorded three to five days prior to slaughter. Carcass measurements were taken, and one side of each carcass was fabricated into retail cuts. Stepwise regression analysis was used to compare possible models for prediction of either kilograms or percent retail product from carcass mesaurements and ultrasound measures. Results indicate that possible prediction models for percent or kilograms of retail products using RTU measures were similar in their predictive power and accuracy when compared to models derived from carcass measurements. Both fat thickness and ribeye area were over-predicted when measured ultrasonically compared to measurements taken on the carcass in the cooler. The mean absolute differences for both traits are larger than the mean differences, indicating that some images were interpreted to be larger and some smaller than actual carcass measurements. Ultrasound measurements of REA and FT had positive correlations with carcass measures of the same traits (r=.96 for REA and r=.99 for FT). Standard errors of prediction currently are being used as the standard to certify ultrasound technicians for accuracy. Regression equations using live weight (LW), rib eye area (REAU) and subcutaneous fat thickness (FTU) between 12(th) and 13 (th) ribs and also over the biceps femoris muscle (FTP8) by ultrasound explained 95% of the variation in the hot carcass weight when measure immediately before slaughter.

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The objective of this work was to estimate the correlations among measurements taken in vivo with ultrasound equipment with some carcass traits measured after slaughter. Twenty eight Mediterranean bulls, with average shrunk body weight of 330 kg and 14 months of age, were fed by 120 days with high concentrate diets. The shrunk body weight, the ribeye area (REAU), the back fat thickness (FTU) over the Longissimus dorsi muscle between 12(a) and 13(a) ribs and rump fat (EGP8U), were measured at 28 days intervals. Real-time ultrasound equipment Piemedical Scanner 200 VET, with 18 cm linear array transducer was utilized. After the slaughter, the hot carcass weight (PCQ) and the kidney, pelvic and inguinal fat (GRPI) were weighted and the dressing percentage (DP) calculated. After 24 hours of cooling the ribeye area (REAC), backfat thickness (FTC) and rump fat (EGP8C) were measured. Both the REAC, FTC and EGP8C were underestimated by ultrasound measurements. The Pearson correlation coefficients for ribeye area, backfat thickness and rump fat measured in the carcass and with ultrasound, were 0.96, 0.99 and 0.91, respectively. The coefficient between DP and REAU was 0.47; 0.45 between DP and REAC, 0.56 between DP and FTU and 0.58 between DP and FTC. DP presented a 0.59 correlation coefficient with EGP8U. The Spearman correlation was estimated between REAU and REAC, FTU and FTC, EGP8U and EGP8C, and the values were 0.96, 0.99 and 0.91,respectively. The ultrasound measures could be used to estimate carcass traits in buffaloes with good accuracy.

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Background. Previous studies from our laboratory have shown that luminal perfusion with arginine vasopressin (AVP) stimulates distal tubule secretory potassium flux (J(K)) via V1 receptors (Am J Physiol 278: F809- F816, 2000). In the present work, we investigate the cell signaling mechanism of this process.Methods. In vivo stationary microperfusion was performed in rat cortical distal tubules and luminal K was measured using double K+ resin/reference microelectrodes.Results. In control conditions, J(K) was 0.71 +/- 0.05 nmol. cm(-2).second(-1); this process was inhibited (14%) by 10(-5) mol/L 8-bromo-cyclic adenosine monophosphate (cAMP), and increased by 35% with 10(-8) mol/L phorbol ester [phorbol 12-myristate 13-acetate (PMA), which activates protein kinase C (PKC)]. During luminal perfusion with 10(-11) mol/L AVP, J(K) increased to 0.88 +/- 0.08 nmol. cm(-2).seconds(-1). In the presence of 10(-11) mol/L AVP, J(K) was not affected by 10(-4) mol/L H89, a blocker of protein kinase A (PKA), but was inhibited (45%) by 10(-5) mol/L staurosporine, an inhibitor of PKC, and by 41% during perfusion with 5 x 10(-5) mol/L of the cell Ca2+ chelator bis (2-aminophenoxy) ethane-tetraacetic acid (BAPTA). In order to study the role of Ca2+-dependent K channels in the luminal hormonal action, the tubules were perfused with 5 mmol/L tetraethylammonium chloride (TEA) or 10(-7) mol/L iberiotoxin, in the presence of AVP, and JK was significantly reduced by both agents. Iberiotoxin reduced AVP-stimulated J(K) by 36.4%, and AVP-independent J(K) (after blocking V1 receptors) by only 16%.Conclusion. The results suggest that the luminal V1-receptor effect of AVP on J(K) was mediated by the phospholipase C (PLC)/ Ca2+/PKC signaling path and not by adenylate cyclase/cAMP/PKA, therefore probably acting on maxi-potassium channels.

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This study records the occurrence of a blue shark Prionace glauca foetus, with morphological abnormalities in the trunk and cephalic region, from a female caught by a pelagic longline in October 2003, in southern Brazil. (c) 2006 the Authors.

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Asiatic citrus canker, caused by Xanthomonas smithii ssp. citri, formerly X. axonopodis pv. citri, is one of the most serious phytosanitary problems in Brazilian citrus crops. Experiments were conducted under controlled conditions to assess the influence of temperature and leaf wetness duration on infection and subsequent symptom development of citrus canker in sweet orange cvs Hamlin, Natal, Pera and Valencia. The quantified variables were incubation period, disease incidence, disease severity, mean lesion density and mean lesion size at temperatures of 12, 15, 20, 25, 30, 35, 40 and 42 degrees C, and leaf wetness durations of 0, 4, 8, 12, 16, 20 and 24 h. Symptoms did not develop at 42 degrees C. A generalized beta function showed a good fit to the temperature data, severity being highest in the range 30-35 degrees C. The relationship between citrus canker severity and leaf wetness duration was explained by a monomolecular model, with the greatest severity occurring at 24 h of leaf wetness, with 4 h of wetness being the minimum duration sufficient to cause 100% incidence at optimal temperatures of 25-35 degrees C. Mean lesion density behaved similarly to disease severity in relation to temperature variation and leaf wetness duration. A combined monomolecular-beta generalized model fitted disease severity, mean lesion density or lesion size as a function of both temperature and duration of leaf wetness. The estimated minimum and maximum temperatures for the occurrence of disease were 12 degrees C and 40 degrees C, respectively.

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Neoplastic diseases are typically diagnosed by biopsy and histopathological evaluation. The pathology report is key in determining prognosis, therapeutic decisions, and overall case management and therefore requires diagnostic accuracy, completeness, and clarity. Successful management relies on collaboration between clinical veterinarians, oncologists, and pathologists. To date there has been no standardized approach or guideline for the submission, trimming, margin evaluation, or reporting of neoplastic biopsy specimens in veterinary medicine. To address this issue, a committee consisting of veterinary pathologists and oncologists was established under the auspices of the American College of Veterinary Pathologists Oncology Committee. These consensus guidelines were subsequently reviewed and endorsed by a large international group of veterinary pathologists. These recommended guidelines are not mandated but rather exist to help clinicians and veterinary pathologists optimally handle neoplastic biopsy samples. Many of these guidelines represent the collective experience of the committee members and consensus group when assessing neoplastic lesions from veterinary patients but have not met the rigors of definitive scientific study and investigation. These questions of technique, analysis, and evaluation should be put through formal scrutiny in rigorous clinical studies in the near future so that more definitive guidelines can be derived.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)