915 resultados para Timber elements joints


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Objective. To investigate the mechanism underlying neutrophil migration into the articular cavity in experimental arthritis and, by extension, human-inflammatory synovitis. Methods. Antigen-induced arthritis (AIA) was generated in mice with methylated bovine serum albumin (mBSA). Migration assays and histologic analysis were used to evaluate neutrophil recruitment to knee joints. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay. Antibodies and pharmacologic inhibitors were used in vivo to determine the role of specific disease mediators. Samples of synovial tissue and synovial fluid from rheumatoid arthritis (RA) or osteoarthritis patients were evaluated for CXCL1 and CXCL5 expression. Results. High levels of CXCL1, CXCL5, and leukotriene B-4 (LTB4) were expressed in the joints of arthritic mice. Confirming their respective functional roles, repertaxin (a CXCR1/CXCR2 receptor antagonist), anti-CXCL1 antibody, anti-CXCL5 antibody, and MK886 (a leukotriene synthesis inhibitor) reduced mBSA-induced neutrophil migration to knee joints. Repertaxin reduced LTB4 production in joint tissue, and neutrophil recruitment induced by CXCL1 or CXCL5 was inhibited by MK886, suggesting a sequential mechanism. Levels of both CXCL1 and CXCL5 were elevated in synovial fluid and were released in vitro by RA synovial tissues. Moreover, RA synovial fluid neutrophils stimulated with CXCL1 or CXCL5 released significant amounts of LTB4. Conclusion. Our data implicate CXCL1, CXCL5, and LTB4, acting sequentially, in neutrophil migration in AIA. Elevated levels of CXCL1 and CXCL5 in the synovial compartment of RA patients provide robust comparative data indicating that this mechanism plays a role in inflammatory joint disease. Together, these results suggest that inhibition of. CXCL1, CXCL5, or LTB4 may represent a potential therapeutic strategy in RA.

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The sciarid DNA puff C4 BhC4-1 gene is amplified and transcribed in salivary glands at the end of the larval stage. In transgenic Drosophila, the BhC4-1 promoter drives transcription in prepupal salivary glands and in the ring gland of late embryos. A bioinformatics analysis has identified 162 sequences similar to distinct regions of the BhC4-1 proximal promoter, which are predominantly located either in 5` or 3` regions or introns in the Drosophila melanogaster genome. A significant number of the identified sequences are found in the regulatory regions of Drosophila genes that are expressed in the salivary gland. Functional assays in Drosophila reveal that the BhC4-1 proximal promoter contains both a 129 bp (-186/-58) salivary gland enhancer and a 67 bp (-253/-187) ring gland enhancer that drive tissue specific patterns of developmentally regulated gene expression, irrespective of their orientation.

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In recent years, there has been increasing fish consumption in Brazil, largely due to the popularity of Japanese cuisine. No study, however, has previously assessed the presence of inorganic contaminants in species used in the preparation of Japanese food. In this paper, we determined total arsenic, cadmium, chromium, total mercury, and lead contents in 82 fish samples of Tuna (Thunnus thynnus), Porgy (Pagrus pagrus), Snook (Centropomus sp.), and Salmon (Salmo salar) species marketed in Sao Paulo (Brazil). Samples were mineralized in HNO(3)/H(2)O(2) for As, Cd, Cr and Pb, and in HNO(3)/H(2)SO(4)/V(2)O(5) for Hg. Inorganic contaminants were determined after the validation of the methodology using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES); and for Hg, an ICP-coupled hydride generator was used. Concentration ranges for elements analyzed in mg kg(-1) (wet base) were as follows: Total As (0.11-10.82); Cd (0.005-0.047); Cr (0.008-0.259); Pb (0.026-0.481); and total Hg (0.0077-0.9681). As and Cr levels exceeded the maximum limits allowed by the Brazilian law (1 and 0.1 mg kg(-1)) in 51.2 and 7.3% of the total samples studied, respectively. The most contaminated species were porgy (As = 95% and Cr = 10%) and tuna (As 91% and Cr = 10%). An estimation of As, Cd, Pb, and Hg weekly intake was calculated considering a 60 kg adult person and a 350 g consumption of fish per week, with As and Hg elements presenting the highest contribution on diets reaching 222% of provisional tolerable weekly intake (PTWI) for As in porgy and 41% of PTWI for Hg in tuna. (C) 2010 Elsevier Ltd. All rights reserved.

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It has been speculated that the homeopathic treatment of sperm cells in order to improve semen quality could be promising. However, few data is available and its use in spermatozoa requires investigation. It is well established that mitochondrial membrane potential is an important viability parameter of spermatozoa and it is intimately related to reproductive efficiency. In this manner, new technologies in order to improve the activity of sperm cells and, finally, the fecundity of swine herds are of extremely importance. Due to the lack of knowledge of homeopathic treatment effect on spermatozoa, the aim of the present study was to verify the effect of three different homeopathic treatments on viability of boar sperm cells. Three homeopathic treatments composed by Pulsatila CH6, Pulsatila and Avena CH6, Avena CH6 and one control treatment (sucrose) were added to diluted boar semen, which were cooled for 24 or 48 h. Interestingly, no positive effect of homeopathic treatments was observed over semen viability. However, it was demonstrated that the 24 h of cooling storage provided more viable sperm cells when compared to the 48-h period. This effect of storage period on sperm viability was assessed by intact plasmatic membrane, intact acrosome and mitochondrial membrane potential evaluation.

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We develop a new iterative filter diagonalization (FD) scheme based on Lanczos subspaces and demonstrate its application to the calculation of bound-state and resonance eigenvalues. The new scheme combines the Lanczos three-term vector recursion for the generation of a tridiagonal representation of the Hamiltonian with a three-term scalar recursion to generate filtered states within the Lanczos representation. Eigenstates in the energy windows of interest can then be obtained by solving a small generalized eigenvalue problem in the subspace spanned by the filtered states. The scalar filtering recursion is based on the homogeneous eigenvalue equation of the tridiagonal representation of the Hamiltonian, and is simpler and more efficient than our previous quasi-minimum-residual filter diagonalization (QMRFD) scheme (H. G. Yu and S. C. Smith, Chem. Phys. Lett., 1998, 283, 69), which was based on solving for the action of the Green operator via an inhomogeneous equation. A low-storage method for the construction of Hamiltonian and overlap matrix elements in the filtered-basis representation is devised, in which contributions to the matrix elements are computed simultaneously as the recursion proceeds, allowing coefficients of the filtered states to be discarded once their contribution has been evaluated. Application to the HO2 system shows that the new scheme is highly efficient and can generate eigenvalues with the same numerical accuracy as the basic Lanczos algorithm.

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We report on a proof of principle demonstration of an optically driven micromachine element. Optical angular momentum is transferred from a circularly polarized laser beam to a birefringent particle confined in an optical tweezers trap. The optical torque causes the particle to spin at up to 350 Hz, and this torque is harnessed to drive an optically trapped microfabricated structure. We describe a photolithographic method for producing the microstructures and show how a light driven motor could be used in a micromachine system. (C) 2001 American Institute of Physics.

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Trace elements can have a significant effect on the processing and properties of aluminium alloys, including sintered alloys. As little as 0.07 wt% (100 ppm) lead, tin or indium promotes sintering in an Al-Zn-Mg-Cu alloy produced from mixed elemental powders. This is a liquid phase sintering system and thin liquid films form uniformly throughout the alloy in the presence of the trace elements, but liquid pools develop in their absence. Analytical transmission electron microscopy indicates that the trace elements are confined to the interparticle and grain boundary regions. The sintering enhancement is attributed to the segregation of the microalloying addition to the liquid-vapour interface. Because the microalloying elements have a low surface tension, they lower the effective surface tension of the liquid. This reduces the wetting angle and extends the spreading of the liquid through the matrix. An improvement in sintering results. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

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The effects of castration on the primal joints and the cuts of the leg joint of Javan rusa (Cervus timorensis russa) stag carcases was investigated at three slaughter ages (13, 19 and 25 months). Castration reduced the weights of some primal joints in the 19- and 25-months age groups, but not at 13 months. At 19 months, the neck, and neck plus chuck, were heavier by 35 and 17% respectively in entires (P < 0.05), and at 25 months entires had heavier carcases, shoulder, forequarter and hindquarter (P < 0.05). The leg and saddle joints were approximately 39 and 18% of the side, respectively, for both treatments and all ages. The proportions of the neck, and neck plus chuck, were higher (P < 0.05) in 19-month old entires than castrates. There were few significant differences between treatments in the weight or proportion of the hind leg cuts at any slaughter age, but in the 25-months group the silverside was 8% (P < 0.05) heavier in entires. In both castrates and entires, there appeared to be an increase in the percentage of the rump as the animals grew from 13 to 19 months of age. (C) 2001 Elsevier Science Ltd. All rights reserved.

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Thermally unaltered conodont elements, brachiopods. and vertebrates were analyzed with reverse phase high profile liquid chromatography to locate and quantify amino acid remnants of the original organic matrix in the fossils. No consistent similarities in amino acid content were found in conodont taxa. and criteria based on organic residues appear to have no taxonomic significance in the fossils tested from these localities. However, hydroxyproline. an amino acid that is found in the collagen molecules of animals. as well as in the glycoproteins in the cell walls and reproductive tissues of certain plants, is represented in most taxa. The organic matter retained in the impermeable crowns of conodont elements might have been derived originally from a form of collagen. Biochemical analyses. correlated with histochemical tests, demonstrate that organic matter is an integral part of the hyaline tissue of the element crown and not the result of surface contamination. Tests of a range of vertebrate and invertebrate fossil hard tissues produced similar results. The analyses indicate that hyaline tissue in the conodont element crown is not a form of vertebrate enamel. which contains no collagen. Albid tissue. with little or no organic content. is not a form of vertebrate bone or dentine, both based on collagen and low in mineral. Although these results do not help to determine the phylogenetic affinities of conodont animals, they indicate teat conodont elements do not contain hard tissues characteristic of vertebrate animals.