962 resultados para IGBTs in parallel


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DA SILVA, A. S. R., J. R. PAULI, E. R. ROPELLE, A. G. OLIVEIRA, D. E. CINTRA, C. T. DE SOUZA, L. A. VELLOSO, J. B. C. CARVALHEIRA, and M. J. A. SAAD. Exercise Intensity, Inflammatory Signaling, and Insulin Resistance in Obese Rats. Med. Sci. Sports Exerc., Vol. 42, No. 12, pp. 2180-2188, 2010. Purpose: To evaluate the effects of intensity of exercise on insulin resistance and the expression of inflammatory proteins in the skeletal muscle of diet-induced obese (DIO) rats after a single bout of exercise. Methods: In the first exercise protocol, the rats swam for two 3-h bouts, separated by a 45-min rest period (with 6 h in duration-DIO + EXE), and in the second protocol, the rats were exercised with 45 min of swimming at 70% of the maximal lactate steady state-MLSS (DIO + MLSS). Results: Our data demonstrated that both protocols of exercise increased insulin sensitivity and increased insulin-stimulated tyrosine phosphorylation of insulin receptor and insulin receptor substrate 1 and serine phosphorylation of protein kinase B in the muscle of DIO rats by the same magnitude. In parallel, both exercise protocols also reduced protein tyrosine phosphatase 1B activity and insulin receptor substrate 1 serine phosphorylation, with concomitant reduction in c-jun N-terminal kinase and I kappa B kinase activities in the muscle of DIO rats in a similar fashion. Conclusions: Thus, our data demonstrate that either exercise protocols with low intensity and high volume or exercise with moderate intensity and low volume represents different strategies to restore insulin sensitivity with the same efficacy.

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One of the electrical impedance tomography objectives is to estimate the electrical resistivity distribution in a domain based only on electrical potential measurements at its boundary generated by an imposed electrical current distribution into the boundary. One of the methods used in dynamic estimation is the Kalman filter. In biomedical applications, the random walk model is frequently used as evolution model and, under this conditions, poor tracking ability of the extended Kalman filter (EKF) is achieved. An analytically developed evolution model is not feasible at this moment. The paper investigates the identification of the evolution model in parallel to the EKF and updating the evolution model with certain periodicity. The evolution model transition matrix is identified using the history of the estimated resistivity distribution obtained by a sensitivity matrix based algorithm and a Newton-Raphson algorithm. To numerically identify the linear evolution model, the Ibrahim time-domain method is used. The investigation is performed by numerical simulations of a domain with time-varying resistivity and by experimental data collected from the boundary of a human chest during normal breathing. The obtained dynamic resistivity values lie within the expected values for the tissues of a human chest. The EKF results suggest that the tracking ability is significantly improved with this approach.

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Mitochondria are important intracellular sources and targets of reactive oxygen species (ROS), while flavonoids, a large group of secondary plant metabolites, are important antioxidants. Following our previous study on the energetics of mitochondria exposed to the flavonoids quercetin, taxifolin, catechin and galangin, the present work addressed the antioxidant activity of these compounds (1-50 mu mol/L) on Fe2+/citrate-mediated membrane lipid peroxidation (LPO) in isolated rat liver mitochondria, running in parallel studies of their antioxidant activity in non-organelle systems. Only quercetin inhibited the respiratory chain of mitochondria and only galangin caused uncoupling. Quercetin and galangin were far more potent than taxifolin and catechin in affording protection against LPO (IC50 = 1.23 +/- 0.27 and 2.39 +/- 0.79 mu mol/L, respectively), although only quercetin was an effective scavenger of both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals. These results, together with the previous study, suggest that the 2,3-double bond in conjugation with the 4-oxo function in the flavonoid structure are major determinants of the antioxidant activity of flavonoids in mitochondria, the presence of an o-di-OH structure on the B-ring, as occurs in quercetin, favours this activity via superoxide scavenging, while the absence of this structural feature in galangin, favours it via a decrease in membrane fluidity and/or mitochondrial uncoupling. Copyright (c) 2008 John Wiley & Sons, Ltd.

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The results presented in this report form a part of a larger global study on the major issues in BPM. Only one part of the larger study is reported here, viz. interviews with BPM experts. Interviews of BPM tool vendors together with focus groups involving user organizations, are continuing in parallel and will set the groundwork for the identification of BPM issues on a global scale via a survey (including a Delphi study). Through this multi-method approach, we identify four distinct sets of outcomes. First, as is the focus of this report, we identify the BPM issues as perceived by BPM experts. Second, the research design allows us to gain insight into the opinions of organisations deploying BPM solutions. Third, an understanding of organizations’ misconceptions of BPM technologies, as confronted by BPM tool vendors is obtained. Last, we seek to gain an understanding of BPM issues on a global scale, together with knowledge of matters of concern. This final outcome is aimed to produce an industry driven research agenda which will inform practitioners and in particular, the research community world-wide on issues and challenges that are prevalent or emerging in BPM and related areas.

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The phospholipids in plasma membranes of erythrocytes, as well as platelets, lymphocytes and other cells are asymmetrically distributed, with sphingomyelin and phosphatidylcholine residing predominantly in the outer leaflet of the bilayer, and phosphatidylserine and phosphatidylethanolamine in the inner leaflet. It is known that Ca2+ can disrupt the phospholipid asymmetry by activation of a protein known as phospholipid scramblase, which affects bidirectional phospholipid movement in a largely non-selective manner. As Ca2+ also inhibits aminophospholipid translocase, whose Mg2+-ATPase activity is responsible for active translocation of aminophospholipids from the outer to the inner leaflet, it is important to accurately determine the sensitivity of scramblase to intracellular free Ca2+. In the present study we have utilized the favourable K-d, of Mag-fura-2 for calcium in the high micromolar range to determine free Ca2+ levels associated with lipid scrambling in resealed human red cell ghosts. The Ca2+ sensitivity was measured in parallel to the translocation of a fluorescent-labelled lipid incorporated into the ghost bilayer. The phospholipid scrambling was found to be half-maximally activated at 63-88 mu M free intracellular Ca2+. The wider applicability of the method and the physiological implications of the calcium sensitivity determined is discussed.

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Establishment of long-term potentiation (LTP) at perforant path synapses is highly correlated with increased expression of Egr and AP-1 transcription factors in rat dentate gyrus granule cells. We have investigated whether increased transcription factor levels are reflected in increased transcription factor activity by assessing Egr and AP-I DNA binding activity using gel shift assays. LTP produced an increase in binding to the Egr element, which was NMDA receptor-dependent and correlated closely with our previously reported increase in Egr-1 (zif/268) protein levels. Supershift analysis confirmed involvement of Egr-1, but not Egr-2 in the DNA binding activity. AP-1 DNA binding was also rapidly elevated in parallel with protein levels, however, the peak increase in activity was delayed until 4 h, a time point when we have previously shown that only jun-D protein was elevated. These data indicate that binding of Egr-1 and AP-1 to their response elements is increased in two phases. This may result in activation of distinct banks of target genes which contribute to the establishment of persistent LTP. (C) 2000 Elsevier Science B.V. All rights reserved.

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Recent research has begun to provide support for the assumptions that memories are stored as a composite and are accessed in parallel (Tehan & Humphreys, 1998). New predictions derived from these assumptions and from the Chappell and Humphreys (1994) implementation of these assumptions were tested. In three experiments, subjects studied relatively short lists of words. Some of the Lists contained two similar targets (thief and theft) or two dissimilar targets (thief and steal) associated with the same cue (ROBBERY). AS predicted, target similarity affected performance in cued recall but not free association. Contrary to predictions, two spaced presentations of a target did not improve performance in free association. Two additional experiments confirmed and extended this finding. Several alternative explanations for the target similarity effect, which incorporate assumptions about separate representations and sequential search, are rejected. The importance of the finding that, in at least one implicit memory paradigm, repetition does not improve performance is also discussed.

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Fragile sites appear visually as nonstaining gaps on chromosomes that are inducible by specific cell culture conditions. Expansion of CGG/ CCG repeats has been shown to be the molecular basis of all five folate-sensitive fragile sites characterized molecularly so far, i.e., FRAXA, FRAXE, FRAXF, FRA11B, and FRA16A. In the present study we have refined the localization of the FRA10A folate-sensitive fragile site by fluorescence in situ hybridization. Sequence analysis of a BAC clone spanning FRA10A identified a single, imperfect, but polymorphic CGG repeat that is part of a CpG island in the 5'UTR of a novel gene named FRA10ACl. The number of CGG repeats varied in the population from 8 to 13. Expansions exceeding 200 repeat units were methylated in all FRA10A fragile site carriers tested. The FRA10ACl gene consists of 19 exons and is transcribed in the centromeric direction from the FRA10A repeat. The major transcript of similar to 1450 nt is ubiquitously expressed and codes for a highly conserved protein, FRA10ACl, of unknown function. Several splice variants leading to alternative 3' ends were identified (particularly in testis). These give rise to FRA10ACl proteins with altered COOH-termini. Immunofluorescence analysis of full-length, recombinant EGFP-tagged FRA10ACl protein showed that it was present exclusively in the nucleoplasm. We show that the expression of FRA10A, in parallel to the other cloned folate-sensitive fragile sites, is caused by an expansion and subsequent methylation of an unstable CGG trinucleotide repeat. Taking advantage of three cSNPs within the FRA10ACl gene we demonstrate that one allele of the gene is not transcribed in a FRA10A carrier. Our data also suggest that in the heterozygous state FRA10A is likely a benign folate-sensitive fragile site. (C) 2004 Elsevier Inc. All rights reserved.

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Background: A survey of pathology reporting of breast cancer in Western Australia in 1989 highlighted the need for improvement. The current study documents (1) changes in pathology reporting from 1989 to 1999 and (2) changes in patterns of histopathological prognostic indicators for breast cancer following introduction of mammographic screening in 1989. Methods: Data concerning all breast cancer cases reported in Western Australia in 1989, 1994 and 1999 were retrieved using the State Cancer Registry, Hospital Morbidity data system, and pathology laboratory records. Results: Pathology reports improved in quality during the decade surveyed. For invasive carcinoma, tumour size was not recorded in 1.2% of pathology reports in 1999 compared with 16.1% in 1989 (rho<0.001). Corresponding figures for other prognostic factors were: tumour grade 3.3% and 51.6% (rho<0.001), tumour type 0.2% and 4.1% (rho<0.001), vascular invasion 3.7% and 70.9% (rho<0.001), and lymph node status 1.9% and 4.5% (rho=0.023). In 1999, 5.9% of reports were not in a synoptic/checklist format, whereas all reports were descriptive in 1989 (rho<0.001). For the population as a whole, the proportion of invasive carcinomas <1 cm was 20.9% in 1999 compared with 14.5% in 1989 (rho<0.001); for tumours <2 cm the corresponding figures were 65.4% and 59.7% (rho=0.013). In 1999, 30.5% of tumours were histologically well-differentiated compared with 10.6% in 1989 (rho<0.001), and 61.7% were lymph node negative in 1999 compared with 57.1% in 1989 (rho=0.006). Pure ductal carcinoma in situ (DCIS) constituted 10.9% and 7.9% of total cases of breast carcinoma in 1999 and 1989, respectively (rho=0.01). Conclusions: Quality of pathology reporting improved markedly over the period, in parallel with adoption of stanclardised synoptic pathology reports. By 1999, recording of important prognostic information was almost complete. Frequency of favourable prognostic factors generally increased over time, reflecting expected effects of mammographic screening.

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Fast synaptic neurotransmission is mediated by transmitter-activated conformational changes in ligand-gated ion channel receptors, culminating in opening of the integral ion channel pore. Human hereditary hyperekplexia, or startle disease, is caused by mutations in both the intracellular or extracellular loops flanking the pore-lining M2 domain of the glycine receptor alpha 1 subunit. These flanking domains are designated the M1-M2 loop and the M2-M3 loop respectively. We show that four startle disease mutations and six additional alanine substitution mutations distributed throughout both loops result in uncoupling of the ligand binding sites from the channel activation gate. We therefore conclude that the M1-M2 and M2-M3 loops act in parallel to activate the channel. Their locations strongly suggest that they act as hinges governing allosteric control of the M2 domain. As the members of the ligand-gated ion channel superfamily share a common structure, this signal transduction model may apply to all members of this superfamily.

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Evidence that combined glucosamine sulfate and chondroitin sulfate (Gluchon) or isolated glucosamine (Glu) modifies joint damage in osteoarthritis (OA) is still lacking. We studied joint pain and cartilage damage using the anterior cruciate ligament transection (ACLT) model. Wistar rats were subjected to ACLT of the right knee ( OA) or sham operation. Groups received either Glu (500 mg/kg), Gluchon (500 mg/kg glucosamine +400 mg/kg chondroitin) or vehicle (non-treated-NT) per os starting 7 days prior to ACLT until sacrifice at 70 days. Joint pain was evaluated daily using the rat-knee joint articular incapacitation test. Structural joint damage was assessed using histology and biochemistry as the chondroitin sulfate ( CS) content of cartilage by densitometry (microgram per milligram dried cartilage), comparing to standard CS. The molar weight (Mw) of the CS samples, used as a qualitative biochemical parameter, was obtained by comparing their relative mobility on a polyacrylamide gel electrophoresis to standard CS. Gluchon, but not Glu, significantly reduced joint pain (P<0.05) compared to NT. There was an increase in CS content in the OA group (77.7 +/- 8.3 mu g/mg) compared to sham (53.5 +/- 11.2 mu g/mg) (P<0.05). The CS from OA samples had higher Mw (4:62 +/- 0:24 x 10(4) g/mol) compared to sham (4:18 +/- 0:19 x 10(4) g/mol) (P<0.05). Gluchon administration significantly reversed both the increases in CS content (54.4 +/- 12.1 mu g/mg) and Mw (4:18 +/- 0:2 x 104 g/mol) as compared to NT. Isolated Glu decreased CS content though not reaching statistical significance. Cartilage histology alterations were also significantly prevented by Gluchon administration. Gluchon provides clinical (analgesia) and structural benefits in the ACLT model. This is the first demonstration that biochemical alterations occurring in parallel to histological damage in OA are prevented by Gluchon administration.

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Objective: Physical and psychological incapacity, including fear of falling is related to decreased satisfaction with life in osteoporosis (OP). The impact of a balance exercise program on improving the quality of life is not well established. We have, therefore, investigated the effect of 12-month Balance Training Program in quality of life, functional balance and falls in elderly OP women. Methods: Sixty consecutive women with senile OP were randomized into a Balance Training Group (BT) of 30 patients and no intervention control group (CG) of 30 patients. The BT program included techniques to improve balance over a period of 12 months (1 h exercise session/week and home-based exercises). The quality of life was evaluated before and at the end of the trial using the Osteoporosis Assessment Questionnaire (OPAQ), functional balance was evaluated by Berg Balance Scale (BBS). Falls in the preceding year were noted and compared to the period of study. Results: The comparison of OPAQ variations (INITIAL-FINAL) revealed a significant improvement in quality of life in all parameters for BT compared to CG: well-being (1.61 +/- 1.44 vs. -1.46 +/- 1.32, p < 0001), physical function (1.30 +/- 1.33 vs. -0.36 +/- 0.82, p < 0.001), psychological status (1.58 +/- 1.36 vs. -1.02 +/- 0.83, p < 0.001), symptoms (2.76 +/- 1.96 vs. -0.63 +/- 0.87, p < 0.001), social interaction (1.01 +/- 1.51 vs. 0.35 +/- 1.08, p < 0.001). Of note, this overall benefit was paralleled by an improvement of BBS (-5.5 +/- 5.67 vs. +0.5 +/- 4.88 p < 0.001) and a reduction of falls in 50% in BT group vs. 26.6% for the CG (RR: 1.88, p < 0.025). Conclusion: The long-term Balance Training Program of OP women provides a striking overall health quality of life improvement in parallel with improving functional balance and reduced falls. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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Galectin-3 is a glycan-binding protein that mediates cell-cell and/or cell-extracellular matrix (ECM) interactions. Although galectin-3 is implicated in the progression of various types of cancers, the mechanisms by which galectin-3 enhances metastasis remain unclear. In order to elucidate the role of galectin-3 in the complex multistage process of cancer metastasis, we examined galectin-3 and galectin-3-binding site expression in a series of 82 spontaneous canine mammary tumors (CMT) and two CMT cell lines. Benign CMT tumors exhibited strong nuclear/cytoplasmic galectin-3 immunostaining, whereas malignant CMT tumors and metastases exhibited dramatically decreased galectin-3 expression with the majority of the immunostaining confined to the cytoplasm. Interestingly, intravascular tumor cells overexpressed galectin-3 regardless of their location. CMT-U27 xenografts displayed the same pattern of galectin-3 expression found in spontaneous malignant CMT. In parallel with the downregulation of galectin-3, malignant CMT displayed an overall loss of galectin-3-binding sites in the ECM and focal expression of galectin-3-binding sites mainly detected in intravascular tumor cells and endothelium. Furthermore, loss of galectin-3-binding sites was correlated with the downregulation of GLT25D1, a beta (1-O) galactosyltransferase that modifies collagen, and upregulation of stromal galectin-1. Finally, GLT25D1 mRNA expression was strikingly downregulated in malignant CMT-U27 compared with the benign cell line, and its expression was further de-creased in a galectin-3 knockdown CMT-U27 cell line. We therefore hypothesized that the loss of galectin-3-binding sites in the ECM in conjunction with the overexpression of galectin-3 in specific tumor cell subpopulations are crucial events for the development of mammary tumor metastases.

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Hepatitis B virus (HBV) infection is a significant public health concern with 350 million chronic carriers worldwide. Eight HBV genotypes (A-H) have been described so far. Genotype E (HBV/E) is widely distributed in West Africa and has rarely been found in other continents, except for a few cases in individuals with an African background. In this study, we characterized HBV genotypes in Quibdo, Colombia, by partial S/P gene sequencing, and found, for the first time, HBV/E circulating in nine Afro-Colombian patients who had no recent contact with Africa. The presence of HBV/E in this community as a monophyletic group suggests that it was a result of a recent introduction by some Afro-descendent contact or, alternatively, that the virus came with slaves brought to Colombia. By using sequences with sampling dates, we estimated the substitution rate to be about 3.2x10(-4) substitutions per site per year, which resulted in a time to the most recent common ancestor (TMRCA) of 29 years. In parallel, we also estimated the TMRCA for HBV/E by using two previously estimated substitution rates (7.7x10(-4) and 1.5x10(-5) substitutions per site per year). The TMRCA was around 35 years under the higher rate and 1500 years under the slower rate. In sum, this work reports for the first time the presence of an exclusively African HBV genotype circulating in South America. We also discuss the time of the entry of this virus into America based on different substitution rates estimated for HBV.

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Non-communicable diseases (NCDs) have become a major health priority in Brazil-72% of all deaths were attributable to NCDs in 2007. They are also the main source of disease burden, with neuropsychiatric disorders being the single largest contributor. Morbidity and mortality due to NCDs are greatest in the poor population. Although the crude NCD mortality increased 5% between 1996 and 2007, age-standardised mortality declined by 20%. Declines were primarily for cardiovascular and chronic respiratory diseases, in association with the successful implementation of health policies that lead to decreases in smoking and the expansion of access to primary health care. Of note, however, the prevalence of diabetes and hypertension is rising in parallel with that of excess weight; these increases are associated with unfavourable changes of diet and physical activity. Brazil has implemented major policies for the prevention of NCDs, and its age-adjusted NCD mortality is falling by 1.8% per year. However, the unfavourable trends for most major risk factors pose an enormous challenge and call for additional and timely action and policies, especially those of a legislative and regulatory nature and those providing cost-effective chronic care for individuals affected by NCDs.