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In the present study, Spark Plasma Sintered (SPSed) aluminium matrix composites were severely deformed through Friction stir processing (FSP). Pure aluminium powders and bimodal sized Al2 O3 particles (80 nm and 25 µm) were firstly mixed by ball milling and then consolidated by spark plasma sintering. The effect of the heat input as well the bimodal particle size of the alumina on the materials' microstructure and texture development was evaluated by electron back scattered diffraction (EBSD) analysis. The EBSD analysis clearly showed that the SPSed nanocomposites possessed bimodal aluminium matrix grain structure as well as a crystallography characterised by random texture. In addition, microstructural examination revealed that the partial recrystallisation occurred during SPS for all the nanocomposites. Also, it is revealed that the Zener pinning effect of Al2 O3 nanoparticles retarded recrystallised grain growth following recrystallisation during FSP and then leading to grain refinement of the aluminium. The results revealed that the heat generated during FSP has a remarkable effect on the grain distribution as well as on the crystallographic orientation. Also, a mixture of {112} <110> shear elements and an ideal strong B/B¯ component were observed. The microstructural changes, occurred during FSP in the stir zone region for Al-Al2 O3 nanocomposites, were attributed to both the discontinuous along with the continuous recrystallisation (DDRX/CDRX). It should be pointed out that with increasing the heat input, recrystallised grains portion increased.

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Endogenous ligands of cannabinoid receptors have been discovered recently and include some N-acylethanolamines (NAEs; e.g., N-arachidonoylethanolamine) and some 2-acylglycerols (e.g., sn-2-arachidonoylglycerol). Previously, we found these compounds to be active biologically when administered per os in large quantities to mice. In the present work, piglets were fed diets with and without 20:4n-6 and 22:6n-3 fatty acid precursors of NAEs, in levels similar to those found in porcine milk, during the first 18 days of life, and corresponding brain NAEs were assessed. In piglets fed diets containing 20:4n-6 and 22:6n-3, there were increases in several biologically active NAEs in brain homogenates-20:4n-6 NAE (4-fold), 20:5n-3 NAE (5-fold), and 22:5n-3 and 22:6n-3 NAE (9- to 10-fold). These results support a mechanism we propose for dietary long-chain polyunsaturated fatty acids influences on brain biochemistry with presumed functional sequelae. This paradigm will enable targeted investigations to determine whether and why specific populations such as infants, elderly, or persons suffering from certain clinical conditions may benefit from dietary long-chain polyunsaturated fatty acids.

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Recent studies have shown that the pharmacological tolerance observed after prolonged exposure to synthetic or plant-derived cannabinoids in adult rats is accompanied by down-regulation/desensitization of brain cannabinoid receptors. However, no evidence exists on possible changes in the contents of the endogenous ligands of cannabinoid receptors in the brain of cannabinoid-tolerant rats. The present study was designed to elucidate this possibility by measuring, by means of isotope dilution gas chromatography/mass spectrometry, the contents of both anandamide (arachidonoylethanolamide; AEA) and its biosynthetic precursor, N-arachidonoylphosphatidylethanolamine (NArPE), and 2-arachidonoylglycerol (2-AG) in several brain regions of adult male rats treated daily with delta9-tetrahydrocannabinol (delta9-THC) for a period of 8 days. The areas analyzed included cerebellum, striatum, limbic forebrain, hippocampus, cerebral cortex, and brainstem. The same regions were also analyzed for cannabinoid receptor binding and WIN-55,212-2-stimulated guanylyl-5'-O-(gamma-[35S]thio)-triphosphate ([35S]GTPgammaS) binding to test the development of the well known down-regulation/desensitization phenomenon. Results were as follows: As expected, cannabinoid receptor binding and WIN-55,212-2-stimulated [35S]GTPgammaS binding decreased in most of the brain areas of delta9-THC-tolerant rats. The only region exhibiting no changes in both parameters was the limbic forebrain. This same region exhibited a marked (almost fourfold) increase in the content of AEA after 8 days of delta9-THC treatment. By contrast, the striatum exhibited a decrease in AEA contents, whereas no changes were found in the brainstem, hippocampus, cerebellum, or cerebral cortex. The increase in AEA contents observed in the limbic forebrain was accompanied by a tendency of NArPE levels to decrease, whereas in the striatum, no significant change in NArPE contents was found. The contents of 2-AG were unchanged in brain regions from delta9-THC-tolerant rats, except for the striatum where they dropped significantly. In summary, the present results show that prolonged activation of cannabinoid receptors leads to decreased endocannabinoid contents and signaling in the striatum and to increased AEA formation in the limbic forebrain. The pathophysiological implications of these findings are discussed in view of the proposed roles of endocannabinoids in the control of motor behavior and emotional states.

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Two new scalaranes (1 and 2) have been isolated from the dorid nudibranch Glossodoris atromarginataand its prey. The structures were deteremined by spectral techniques and confirmed by chemical methods. Compounds 1 and 3 showed selective cytotoxic activity against human thyroid carcinoma.

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In the period 1992-1997, 211 cases of acute pancreatitis were observed: 81 grave cases; 130 slight cases. The ERCP and endoscopic sphincterotomy were performed in 84 cases. From the critical revision 2 groups of patients emerged, homogeneous for etiology and clinical classification, the first submitted to ERCP within 72 hours from the entry in hospital; the other after 72 from the hospitalisation. The "t" Students test for small numbers was significant (p < 001) showing a decrease of hospitalisation in the submitted group to ERCP within 3 days. In 42 cases of acute pancreatitis observed in 1997 a study was made about the hospitalised patients' costs. Two homogeneous groups of acute and slight pancreatitis have been considered. The parameters analysed were about the costs of: a) days hospitalisations; b) pharmaceutical expenses; c) hematological examination; d) surgical operation, laparothomic and laparoscopic surgery; e) instrumental examination. The results of the expense have been compared with the obtained DRG, both for each single case and also for homogeneous group of grave and slight pancreatitis. This comparison showed that the obtained gain through DRG is: a) insufficient to cover the expenses of the grave pancreatitis cases; b) clearly positive in the slight cases. This last result has been very important in the final balance; in fact is only for this positive result that final balance was economically favourable.

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The Authors considered the incidences of the urgencies for allergic pathology arrived at Santobon Hospital during January-December 1992. In the period of twelve months a whole of 42.702 children came to Hospital; among them 4.359 showed an allergic pathology with a clear prevalence for wheezing and asthma. In addition it was observed too that an allergic mainly affected male children.

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This paper describes the technical development as well as results obtained with the method of bone lengthening developed by the author and used over the past fifteen years for the treatment of short-statured conditions not susceptible to hormonal treatment.

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Cylindrical asymmetrical nonimaging concentrators with receivers based on tin absorbers immersed in dielectric rhombuses are introduced and shown to be ideal. They have the same concentration factor as dielectric filled devices but require only a small amount of dielectric around the absorber. The asymmetric shape and nontracking property of the collectors allow their arrangement in flat panels that, integrated with a supporting thermal insulator, may be the roof or the wall of a small building situated in a remote locality. This would passively satisfy the electric requirements of the building.

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Two ideal concentrators with fin absorbers in dielectric rhombuses are described. Expressions for the design, height, and mirror length are derived. The devices have a concentration factor (n/sin ?(M)) that is clearly higher than the traditional air-filled ideal concentrators. They do not require more mirrors or space and, when such easily available dielectrics as glass and water are used, offer useful configurations for purposes such as the collection of solar energy.

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