796 resultados para border development and integration


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The normal growth, differentiation and maintenance of the morphofunctional integrity of the prostate gland are dependent on the interaction of constant levels of androgens with their receptors. The need to study the responses to hormones under several conditions and the effect of their blockage is due to the fact that the human prostate is the site of a great number of age-related diseases, and the ones with a major medical importance are prostate cancer (Cap) and benign prostatic hyperplasia (BPH), which can both be treated with androgen suppression. Seventy-five male gerbils were divided, randomly, into 3 groups of 25 animals each, where each group corresponded to one phase of postnatal development. In each phase, it was possible to morphologically and stereologically analyze the compartments of prostatic ventral lobe, as well as to immunohistochemically analyze the degree of expression of androgen receptors (ARs) after the androgen blockage therapies. In addition, it was possible to establish the hormonal dosage of serum testosterone levels given the comparative approach of the expression of androgen receptors. There is a pattern of AR distribution in the prostatic ventral lobe throughout postnatal development, in which the younger the animal is the higher, the interaction of circulating androgens that stimulate the AR expression in both the epithelial and stromal compartments. The androgen blockage therapies decreased AR expression in the prostatic compartments, but the androgen reposition after these blockages was not sufficient to recover the glandular structure or stimulate the AR expression up to normal physiological conditions. Both the regulation and distribution of androgen receptors along the gerbil prostatic tissues are complex mechanisms that are likely to be genetically regulated by androgens prenatally or by other factors that are still unknown. This rodent species seems to be a valuable model in the attempt to improve the understanding of the morphophysiological and pathological behavior of this important gland in humans throughout aging and to stimulate new therapeutic ideas to fight prostate cancer. (C) 2008 Elsevier Ltd. All rights reserved.

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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)

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

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

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

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A laboratory setup was designed and put into operation for the development of solid oxide fuel cells (SOFCs). The whole project consisted of the preparation of the component materials: anode, cathode and electrolyte, and the buildup of a hydrogen leaking-free sample chamber with platinum leads and current collectors for measuring the electrochemical properties of single SOFCs. Several anode-supported single SOFCs of the type (ZrO(2):Y(2)O(3)+NiO) thick anode/(ZrO(2):Y(2)O(3)) thin electrolyte/(La(0.65)Sr(0.35)MnO(3)+ZrO(2):Y(2)O(3)) thin cathode have been prepared and tested at 700 and 800 degrees C after in situ H(2) anode reduction. The main results show that the slurry-coating method resulted in single-cells with good reproducibility and reasonable performance, suggesting that this method can be considered for fabrication of SOFCs. (c) 2005 Elsevier B.V. All rights reserved.

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This report describes the development of a behaviour chamber and the validation of the chamber to measure locomotor activity of a horse, Locomotor activity was detected by four Mini-beam sensors and recorded on a data logger every 5 min for 22 h. Horses were more active during daytime than in the evening, which was at least partially related to human activity in their surroundings. To validate the ability of the chambers to detect changes in activity, fentanyl citrate and xylazine HCl, agents well-characterized as a stimulant and a depressant, respectively, were administered to five horses. Fentanyl citrate (0.016 mg/kg) significantly increased locomotor activity which persisted for 30 min, Xylazine HCl (1 mg/kg) significantly reduced locomotor activity for 90 min. Amitraz produced a dose-dependent decrease in locomotor activity, lasting 75 min for the 0.05 mg/kg dose, 120 min for the 0.10 mg/kg dose, and 180 min for the 0.15 mg/kg dose, In a separate experiment, yohimbine administration immediately reversed the sedative effect of amitraz, This suggests there is a similarity in the mode of action of amitraz, xylazine and detomidine, as yohimbine acts primarily by blocking central alpha 2-adrenoceptors that are stimulated by agents like xylazine, There was also a significant decrease in locomotor activity following injection of detomidine (0.02, 0.04 and 0.08 mg/kg) for 1.5, 3.5 and 5.0 h, respectively, the locomotor chamber is a useful, sensitive and highly reproducible tool for measuring spontaneous locomotor activity in the horse, which allows investigators to determine an agent's average time of onset, duration and intensity of effect on movement.

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Variations on the microstructure development and on the electrical properties of SnO2-based varistors are discussed on the basis of the oxygen vacancies created or annihilated by the presence of different additives. Electron paramagnetic resonance (EPR) analysis of sintered samples evidenced a substantial increase in the paramagnetic oxygen vacancies concentration when Nb2O5 is added to the SnO2 center dot Co3O4 system. on the other hand, the observed diminution in the concentration of such species after the addition of Fe2O3 indicates solid solution formation. The quantification of paramagnetic oxygen vacancies allowed to confirm the proposed substitutions taking place in the lattice during sintering. These findings are supported by scanning electron microscopy, by density measurements and by current density versus electric field curves. The characterization of secondary phases through EDS assisted SEM and TEM is also reported in this work.

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A good cover crop should have a vigorous early development and a high potential for nutrient uptake that can be made available to the next crop. In tropical areas with relatively dry winters drought tolerance is also very important. An experiment was conducted to evaluate the early development and nutrition of six species used as cover crops as affected by sub-superficial compaction of the soil. The plants (oats, pigeon pea, pearl millet, black mucuna, grain sorghum, and blue lupin) were grown in pots filled with soil subjected to different subsurface compaction levels (bulk densities of 1.12, 1.16, and 1.60 mg m(-3)) for 39 days. The pots had an internal diameter of 10 cm and were 33.5 cm deep. Grasses were more sensitive to soil compaction than leguminous plants during the initial development. Irrespective of compaction rates, pearl millet and grain sorghum were more efficient in recycling nutrients. These two species proved to be more appropriate as cover crops in tropical regions with dry winters, especially if planted shortly before spring.

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A detailed study of floral ontogeny, anatomy, and embryology in two (of six) species of Pharus is presented as part of a series of comparative investigations on early-divergent grasses. Pharus is a taxonomically isolated genus belonging to the earliest-diverging grass lineage with a true grass spikelet. It is unusual in possessing remarkably dimorphic florets: male florets possess two lodicules, six stamens, and a pistillode, whereas female florets lack lodicules entirely but possess six staminodes and a tricarpellary ovary with three stigmas. The rudimentary lodicules in male florets are initiated after the stamen whorls. There are most commonly six androecial organs, but in some florets, a five-staminate condition was observed, resulting from suppression of the abaxial stamen from the inner whorl, or even a four-staminate condition resulting from subsequent fusion of the two adaxial outer stamens (i.e., elements of both whorls). Thus, the pattern of floral zygomorphy in Pharus differs from that of many other grasses. Centrifixed anther attachment is reported for the first time in Pharus, resembling the condition in another early-divergent grass, Anomochloa, though anthers are introrse in Anomochloa compared with latrorse in Pharus. Anther wall development is of the reduced type in Pharus, in contrast to most other monocots. Microsporogenesis is of the successive type, as in many other monocots. The ovary develops from three distinct primordia and is unilocular with a single ovule and a pronounced ovary beak that is highly characteristic of Pharus. There is a hollow style, in contrast to the solid styles that are common in many other grasses. The embryo is highly differentiated, as in other grasses, with a distinct epiblast and a small cleft between the scutellum and the coleorhiza.