845 resultados para 020501 Classical and Physical Optics


Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this experiment was to investigate the effects of different particle sizes, expressed as Geometric Mean Diameter (GMD) of corn (0.336mm, 0.585mm, 0.856mm and 1.12mm) of mash and pelleted broiler chicken diets on the weight of the gizzard, duodenum and jejunum+ileum; on the pH of the gizzard and small intestine and on the characteristics of the duodenal mucous layer (number and height of villi and crypt depth) in 42-day-old broilers. The physical form and the particle size of the diet had no significant effect on gizzard and intestine pH (p > 0.05). A greater gizzard weight was seen in the birds receiving pelleted diet and particle size of 0.336mm (p < 0.008). However, for the particle sizes of 0.856 and 1.12 mm, a greater weight was found in birds that received mash diet (p < 0.039 and p < 0.006, respectively). Also, gizzard weight was greater with increasing corn GMD independent of the physical form of the diet. In the mash diet, the increase in particle size promoted a quadratic response in the weight of duodenum and jejunum + ileum. The pelleted diet promoted a greater number of villi per transverse duodenum cut (p < 0.007) and greater crypt depth (p < 0.05). As the particle size increased, there was a linear increase of villus height and crypt depth in the duodenum, irrespective of the physical form of the diet.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work evaluated the viability of one commercial substrate with pinus bark, vermiculite and 30% of coconut fiber for Eucalyptus grandis seedlings production under different water management: 6, 8, 10, 12 e 14 mm day(-1). In relation to the substrates, it was evaluated, before and after the seedlings production, the total content of carbon, nitrogen and organic substances, pH and EC of the extract, the content of macronutrients (P, K, Ca, S, Mg) and macronutrients (B, Fe, Mn, Cu, Zn), as well as total porosity, density and water retention. It was evaluated the macro and mcronutrients accumulation in the roots and in the aerial part of the seedlings, 105 days after sowing. It was concluded that the substrates presented some distinct properties of those cited as ideal for production in containers with irrigation and fertilization. At the end of the production process, both substrates registered nutrient content little influenced by water management what would guarantee the initial development of the plants in the field.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Four aliphatic thermoplastic poly(ester-urethane)s (PEUs) with similar molecular weights but varying polyesters molecular weight (534-1488 g/mol) were prepared from polyester diols, obtained by melt condensation of Azelaic acid and 1,9-Nonanediol, and 1,7-heptamethylene di-isocyanate (HPMDI) all sourced from vegetable oil feedstock. The thermal, and mechanical properties, and crystal structure of PEUs were investigated using DSC, TGA, DMA, tensile analysis and WAXD. For sufficiently long polyester chain, WAXD data indicated no hydrogen bonds polyethylene (PE)-like crystalline packing and for short polyester chains, small crystal domains with significant H-bonded polyamide (PA)-like packing. Crystallinity decreased with decreasing polyester molecular weights. The polymorphism of PEUs and consequently their melting characteristics were found to be largely controlled by polyester segment length. TGA of the PEUs indicated improved thermal stability with decreasing polyester chain length, suggesting a stabilization effect by urethane groups. Mechanical properties investigated by DMA and tensile analysis were found to scale predictably with the overall crystallinity of PEUs. (C) 2012 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Physical exercise and statins, which are recommended for the treatment of dyslipidemia, are independently associated to the occurrence of muscle injury. The objective is analyze the effect of aerobic exercise associated to the use of simvastatin on the morphology of the gastrocnemius muscle. Thirty Wistar rats were divided into six groups, two of which received a standard diet (1 sedentary and 1 exercised) and four (1 sedentary with medication, 1 sedentary without medication, 1 exercised with medication, 1 exercised without medication) received a hypercholesterolemic diet (standard diet with the addition of cholesterol and coconut oil). Simvastatin (20 mg/Kg) was administered five days a week for eight weeks, together with aerobic training on a treadmill (9.75 m/min) for 60 minutes a day. The gastrocnemius muscle was removed, sliced, stained with Hematoxylin-Eosin and submitted to a histochemical reaction to determine mitochondrial activity. The data were analyzed using a paired t-test, analysis of variance and Scheffe's post hoc test (p<0.05). Greater histological alterations were found in the medicated and exercised animals, with a greater frequency of occurrence as well. The histochemical analysis revealed that the medicated groups had fibers with more intensive mitochondrial activity alongside fibers with an absence of reaction. The morphometric analysis revealed no significant differences between groups. It is suggested that simvastatin is a medication that leads to the occurrence of muscle injury and its administration in association with physical activity may exacerbate these injuries. This finding may be related to cellular respiration.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present study examined the interaction of hypercaloric diet (HD) and physical exercise on lipid profile and oxidative stress in serum and liver of rats. Male Wistar rats (60-days-old) were fed with a control (C) and hypercaloric diet (H). Each of the two dietary groups (C and H) was divided into three subgroups (n = 8), sedentary (CS and HS), exercised 2 days a week (CE2 and HE2) and exercised 5 days a week (CE5 and HE5). The swimming was selected as a model for exercise performance. After 8-weeks exercised rats showed decreased lactate dehydrogenase serum activities, demonstrating the effectiveness of the swimming as an aerobic-training protocol. Exercise 5-days a week reduced the body weight gain. Triacylglycerol (TG) and very low-density lipoprotein (VLDL-C) were increased in HD-fed rats. HE5 and CE5 rats had decreased TG, VLDL-C and cholesterol. HE2 rats had enhanced high-density lipoprotein (HDL-C) in serum. No alterations were observed in lipid hydroperoxide (LH), while total antioxidant substances (TAS) were increased in serum of exercised rats. HD-fed rats had hepatic TG accumulation. Superoxide dismutase activities were increased and catalase was decreased in liver of exercised rats. The interaction of HD and physical exercise reduced TAS and enhanced LH levels in hepatic tissue. In conclusion, this study confirmed the beneficial effect of physical exercise as a dyslipidemic-lowering component. Interaction of HD and physical exercise had discrepant effects on serum and liver oxidative stress. The interaction of HID and physical exercise reduced the oxidative stress in serum. HD and physical exercise interaction had pro-oxidant effect on hepatic tissue, suggesting that more studies should be done before using physical exercise as an adjunct therapy to reduce the adverse effects of HD. (c) 2006 Elsevier Ltd. All rights reserved.