151 resultados para tau


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Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease, and corresponds to the most common cause of dementia worldwide. Although not fully understood, the pathophysiology of AD is largely represented by the neurotoxic events triggered by the beta-amyloid cascade and by cytoskeletal abnormalities subsequent to the hyperphosphorylation of microtubule-associated Tau protein in neurons. These processes lead respectively to the formation of neuritic plaques and neurofibrillary tangles, which are the pathological hallmarks of the disease. Clinical benefits of the available pharmacological treatment for AD with antidementia drugs (namely cholinesterase inhibitors and memantine) are unquestionable, although limited to a temporary, symptomatic support to cognitive and related functions. Over the past decade, substantial funding and research have been dedicated to the search and development of new pharmaceutical compounds with disease-modifying properties. The rationale of such approach is that by tackling key pathological processes in AD it may be possible to attenuate or even change its natural history. In the present review, we summarize the available evidence on the new therapeutic approaches that target amyloid and Tau pathology in AD, focusing on pharmaceutical compounds undergoing phase 2 and phase 3 randomized controlled trials.

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A measurement is presented of the ZZ production cross section in the ZZ -> 2l2l' decay mode with l = e, mu and l' = e, mu, tau in proton-proton collisions at root s = 7 TeV with the CMS experiment at the LHC. Results are based on data corresponding to an integrated luminosity of 5.0 fb(-1). The measured cross section sigma(pp -> ZZ) = 6.24(-080)(+0.86) (stat.)(-0.32)(+0.41) (syst.) +/- 0.14 (lumi.) pb is consistent with the standard model predictions. The following limits on ZZZ and ZZ-gamma anomalous trilinear gauge couplings are set at 95% confidence level: -0.011 < f(4)(Z) < 0.012, -0.012 < f(5)(Z) < 0.012, -0.013 < f(4)(gamma) < 0.015, and -0.014 < f(5)(gamma) < 0.014.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Aims and background. The study was undertaken to investigate CCL2/MCP-1, CCL3/MIP-l alpha, CCL4/MIP-1 beta, CCL5/RANTES and CXCL8/IL-8 women with epithelial ovarian cancer.Methods and study design. Sixteen patients diagnosed with epithelial ovarian cancer and 18 healthy women with no evidence of malign neoplasia (control group) aged from 23 to 89 years (mean +/- SEM, 58.7 +/- 2.3) were included. The epithelial ovarian cancer patients underwent laparotomy and debulking surgery Chemokines serum levels were measured by cytometric bead array. Statistical analysis was performed using Mann-Whitney and Kendall's tau. P <0.05 was considered statistically significant for all analyses.Results. The tumor staging (FIGO) was classified into: I in 4 cases (25%), III in 5 cases (31.3%) and stage IV in 7 cases (43.8%). Sera chemokine dosages of CCL2 /MCP-1 and CCL4/MIP-1 beta were lower in epithelial ovarian cancer patients than in the control group (P = 0.021 and P = 0.030, respectively). No significant difference between groups was observed in the levels of CCL3/MIP-l alpha, CCL5/RANTES and CXCL8/IL-8. No association between the chemokines analyzed and tumor stage was found. The serum level of CCL4/MIP-1 beta was correlated with CA-125.Conclusions. The study of serum levels of CCL2/MCP-1, CCL3/MIP-l alpha, CCL4/MIP-1 beta, CCL5/RANTES and CXCL8/IL-8 chemokines in epithelial ovarian cancer patients identified a down-regulation in CCL2/MCP-1 and CCL4/MIP-1 beta, which suggests that the two chemokines may play an important role in the pathophysiology of ovarian cancer.

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We report results from a search for gravitational waves produced by perturbed intermediate mass black holes ( IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency 50 <= f(0)/Hz <= 2000 and decay timescale 0.0001 less than or similar to tau/s less than or similar to 0.1 characteristic of those produced in mergers of IMBH pairs. No significant gravitational wave candidate was detected. We report upper limits on the astrophysical coalescence rates of IMBHs with total binary mass 50 <= M/ M circle dot <= 450 and component mass ratios of either 1: 1 or 4: 1. For systems with total mass 100 <= M/M circle dot <= 150, we report a 90% confidence upper limit on the rate of binary IMBH mergers with nonspinning and equal mass components of 6.9 x 10(-8) Mpc(-3) yr(-1). We also report a rate upper limit for ringdown waveforms from perturbed IMBHs, radiating 1% of their mass as gravitational waves in the fundamental, l = m = 2, oscillation mode, that is nearly three orders of magnitude more stringent than previous results.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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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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The Fokker-Planck equation is studied through its relation to a Schrodinger-type equation. The advantage of this combination is that we can construct the probability distribution of the Fokker-Planck equation by using well-known solutions of the Schrodinger equation. By making use of such a combination, we present the solution of the Fokker-Planck equation for a bistable potential related to a double oscillator. Thus, we can observe the temporal evolution of the system describing its dynamic properties such as the time tau to overcome the barrier. By calculating the rates k = 1/tau as a function of the inverse scaled temperature 1/D, where D is the diffusion coefficient, we compare the aspect of the curve k x 1/D, with the ones obtained from other studies related to four different kinds of activated process. We notice that there are similarities in some ranges of the scaled temperatures, where the different processes follow the Arrhenius behavior. We propose that the type of bistable potential used in this study may be used, qualitatively, as a simple model, whose rates share common features with the rates of some single rate-limited thermally activated processes. (C) 2014 Elsevier B.V. All rights reserved.

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A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.7 fb(-1), collected with the CMS detector at the LHC with root s = 8 TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740 GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a bottom quark. In addition, this mass limit applies directly to top squarks decaying via an R-parity violating coupling. lambda(') (333). The search also considers a similar signature from top squarks undergoing a chargino-mediated decay involving the Rparity violating coupling. lambda(')(3jk). Each top squark decays to a tau lepton, a bottom quark, and two light quarks. Top squarks in this model with masses below 580 GeV are excluded at 95% confidence level. The constraint on the leptoquark mass is the most stringent to date, and this is the first search for top squarks decaying via. lambda(')(3jk). (C) 2014 The Authors. Published by Elsevier B. V.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)