1,435 research outputs found
A predictive phenomenological tool at small Bjorken-x
We present the results from global fits of inclusive DIS experimental data
using the Balitsky-Kovchegov equation with running coupling.Comment: 5 pages, 2 figures, prepared for the Proceedings of 'Hot Quarks 2010
AAMQS: a non-linear QCD description of new HERA data at small-x
We present a global analysis of available data on inclusive structure
functions measured in electron-proton scattering at small values of Bjorken-x,
including the latest data from the combined HERA analysis on reduced cross
sections. Our approach relies on the dipole formulation of DIS together with
the use of the non-linear running coupling BK equation for the description of
the small-x dynamics. With the resulting parametrization we are able to
describe the latest FL data measured by the H1 collaboration. Further, we
discuss the kinematical domain where significant deviations from NLO-DGLAP
should be expected and the ability of non-linnear physics to account for such
deviations.Comment: 4 pages, 2 figures, Proceedings of Quark Matter 2011, Annecy, Franc
Purificação e tratamento químico de carbono para aplicação em síntese de catalisadores de platina
Anais do V Encontro de Iniciação Científica e I Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2016 - 05 e 07 de outubro de 2016 – Sessão Ciências Exatas e da TerraA célula combustível é um sistema eletroquímico com o objetivo de gerar energia elétrica por
meio de reações entre um agente redutor e um agente oxidante as mesmas requerem o uso de
eletrocatalisadores para promover a decomposição eletroquímica de maneira eficiente.
Atualmente, a maioria dos catalisadores utilizados é à base de platina, devido a sua alta
atividade catalítica. Apresenta alto desempenho para a reação de oxidação em meio alcalino
ou ácido, e geralmente, são suportados em condutores de elétrons de elevada área de
superfície específica, como o carbono, o qual pode ser submetido a funcionalização para a
introdução de espécies oxigenadas em sua superfície que podem auxiliar nas propriedades
eletrocatalíticas. No presente trabalho, catalisadores de platina suportados em carbono Vulcan
XC-72R
funcionalizado
foram
sintetizados
pelo
método
de
impregnação.
Os
eletrocatalisadores foram caracterizados por voltametria cíclica e difratometria de raios X
Combination of T-Gel chromatography and immunoaffinity and new protoco to removel immunoglobulins and albumin from serum samples: the case od rheumatoid arthritis
Comunicaciones a congreso
Behçet's disease: New insight into the relationship between procoagulant state, endothelial activation/damage and disease activity
Background: Behçet disease (BD) is associated with a prothrombotic state of unknown origin that may lead to life-threatening events. Calibrated Automated Thrombogram (CAT) and Rotational Thromboelastometry (ROTEM) are two global haemostasis assays that may reveal new insights into the physiopathological mechanisms of the disease and its procoagulant condition. Methods. 23 BD patients who had no signs or symptoms of current thrombosis and 33 age- and sex-matched controls were included in the study. We performed ROTEM and CAT tests and assessed erythrocyte count, platelet count, platelet contribution to clot formation and plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor type 1 (PAI-1), fibrinogen, C-reactive protein (CRP), thrombin-antithrombin III complex (TAT), D-dimer and E-selectin (ES). Results: Both ROTEM and CAT tests showed a hypercoagulable state in the BD patients. Plasma levels of PAI-1, fibrinogen, TAT, CRP and ES were significantly increased in this group compared to controls. The disease activity (DA) was significantly correlated with levels of ES and the maximum clot firmness, and this last one, in turn, correlated with rising levels of ES, PAI-1, CRP and fibrinogen. CAT parameters did not correlate with DA or ES. Conclusions: Both ROTEM and CAT tests reveal that patients with BD have a procoagulant state even in the absence of thrombosis. ROTEM test indicates that increased levels of fibrinogen and PAI-1 may be involved in the prothrombotic state of this pathology, while platelets do not significantly contribute. Moreover, CAT assay demonstrate that plasma from BD patients is able to generate more thrombin than controls in response to the same stimulus and that this effect is independent of the DA and the endothelial impairment suggesting the involvement of another factor in the hypercoagulable state observed in BD patients. This study also shows that endothelium activation/damage may be a contributing factor in both the procoagulant and clinical conditions of BD, as shown by the direct correlation between ES levels, ROTEM parameters and DAThis work was supported by grants from FIS PS09/00531 and FIS PI12/0183
The tyrosine phosphatase CD148 is an essential positive regulator of platelet activation and thrombosis
Platelets play a fundamental role in hemostasis and thrombosis. They are also involved in pathologic conditions resulting from blocked blood vessels, including myocardial infarction and ischemic stroke. Platelet adhesion, activation, and aggregation at sites of vascular injury are regulated by a diverse repertoire of tyrosine kinase–linked and G protein–coupled receptors. Src family kinases (SFKs) play a central role in initiating and propagating signaling from several platelet surface receptors; however, the underlying mechanism of how SFK activity is regulated in platelets remains unclear. CD148 is the only receptor-like protein tyrosine phosphatase identified in platelets to date. In the present study, we show that mutant mice lacking CD148 exhibited a bleeding tendency and defective arterial thrombosis. Basal SFK activity was found to be markedly reduced in CD148-deficient platelets, resulting in a global hyporesponsiveness to agonists that signal through SFKs, including collagen and fibrinogen. G protein–coupled receptor responses to thrombin and other agonists were also marginally reduced. These results highlight CD148 as a global regulator of platelet activation and a novel antithrombotic drug targe
Impact-parameter dependent nuclear parton distribution functions: EPS09s and EKS98s and their applications in nuclear hard processes
We determine the spatial (impact parameter) dependence of nuclear parton
distribution functions (nPDFs) using the -dependence of the spatially
independent (averaged) global fits EPS09 and EKS98. We work under the
assumption that the spatial dependence can be formulated as a power series of
the nuclear thickness functions . To reproduce the -dependence over the
entire range we need terms up to . As an outcome, we release two
sets, EPS09s (LO, NLO, error sets) and EKS98s, of spatially dependent nPDFs for
public use. We also discuss the implementation of these into the existing
calculations. With our results, the centrality dependence of nuclear
hard-process observables can be studied consistently with the globally fitted
nPDFs for the first time. As an application, we first calculate the LO nuclear
modification factor for primary partonic-jet production in
different centrality classes in Au+Au collisions at RHIC and Pb+Pb collisions
at LHC. Also the corresponding central-to-peripheral ratios are
studied. We also calculate the LO and NLO nuclear modification factors for
single inclusive neutral pion production, , at mid- and
forward rapidities in different centrality classes in d+Au collisions at RHIC.
In particular, we show that our results are compatible with the PHENIX
mid-rapidity data within the overall normalization uncertainties given by the
experiment. Finally, we show our predictions for the corresponding
modifications in the forthcoming p+Pb collisions at LHC.Comment: 36 page
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