797 research outputs found
Reversal of thrombin-induced deactivation of CD39/ATPDase in endothelial cells by HMG-CoA reductase inhibition: effects on Rho-GTPase and adenosine nucleotide metabolism
No full textAdenosine triphosphate and diphosphate that activate platelet, leukocyte, and endothelium functions are hydrolyzed by endothelial CD39/ATPDase. Because CD39/ATPDase is downregulated in endothelial cells by inflammation and this may be affected by HMG-CoA reductase inhibitors, we examined the role of cerivastatin and simvastatin in regulation of endothelial CD39/ATPDase expression, metabolism of ATP/ADP, and function in platelets. Thrombin-stimulated endothelial cells in vitro were treated with the statins, and hydrolysis of exogenous ADP and ATP was assessed by high-performance liquid chromatography and malachite green assay. Platelet aggregation studies were performed with endothelial cell supernatants as triggers. CD39/ATPDase surface expression by endothelial cells was determined immunologically by fluorescence-activated cell sorter, mRNA expression by RT-PCR, and thrombin-induced dissociation of Rho-GTPases by Western blotting. Treatment by simvastatin or cerivastatin restored impaired metabolism of exogenous ATP and ADP in thrombin-activated endothelial cells by preventing thrombin-induced downregulation of CD39/ATPDase. In platelet aggregation studies, ATP and ADP supernatants of thrombin-activated endothelial cells were less stimulatory in the presence of statins than in their absence. Data show that statins preserve CD39/ATPDase activity in thrombin-treated endothelial cells involving alterations by statins of Rho-GTPase function and CD39/ATPDase expression. Preservation of adenine nucleotide metabolism may directly contribute to the observed anti-thrombotic and anti-inflammatory actions of statins
Charm fragmentation fractions and c-cbar cross section in p–Pb collisions at sqrt(sNN)=5.02 TeV
No full textThe total charm-quark production cross section per unit of rapidity dσ (cc)/dy, and the fragmentation fractions of charm quarks to different charm-hadron species f (c → hc), are measured for the first time in p–Pb collisions at √sNN = 5.02 TeV at midrapidity (−0.96 < y < 0.04 in the centre-of-mass frame) using data collected by ALICE at the CERN LHC.
The results are obtained based on all the available measurements of prompt production of ground-state charm-hadron species: D0 , D+, D+s , and J/ψ mesons, and Lambda+c and Csi0c baryons. The resulting cross section is dσ (cc)/dy = 219.6 ± 6.3 (stat.) +10.5−11.8 (syst.) +8.3−2.9 (extr.) ± 5.4 (BR) ±4.6 (lumi.)±19.5 (rapidity shape)+15.0 (Omega0c ) mb, which is consistent with a binary scaling of pQCD calculations from pp collisions. The measured fragmentation fractions are compatible with those measured in pp collisions at √s = 5.02 and 13 TeV, showing an increase in the relative production rates of charm baryons with respect to charm mesons in pp and
p–Pb collisions compared with e+e− and e−p collisions. The pT -integrated nuclear modification factor of charm quarks, RpPb(cc) = 0.91 ± 0.04 (stat.)+0.08−0.09 (syst.)+0.05−0.03 (extr.) ±0.03 (lumi.), is found to be consistent with unity and with theoretical predictions including nuclear modifications of the
parton distribution functions
Clinical practice guidelines for the management of atypical haemolytic uraemic syndrome in the United Kingdom
No full textAtypical haemolytic uraemic syndrome (aHUS) is associated with a poor prognosis with regard to survival at presentation, recovery of renal function and transplantation. It is now established that aHUS is a disease of complement dysregulation with mutations in the genes encoding both complement regulators and activators, and autoantibodies against the complement regulator factor H. Identification of the underlying molecular abnormality in an individual patient can now help to guide their future management. In these guidelines we make recommendations for the investigation and management of aHUS patients both at presentation and in the long-term. We particularly address the role of renal transplantation alone and combined liver-kidney transplantation
Energy dependence of forward-rapidity J / ψ and ψ ( 2 S ) production in pp collisions at the LHC
No full textWe present results on transverse momentum (pT) and rapidity (y) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive J / ψ and ψ(2 S) at forward rapidity (2.5 15 GeV/c the non-prompt contribution reaches up to 50% of the total charmonium yield
Measurement of the inclusive J/psi polarization at forward rapidity in pp collisions at root s=8 TeV
No full textCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOWe report on the measurement of the inclusive J/psi polarization parameters in pp collisions at a center of mass energy root s = 8 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb(-1) J/psi resonances are reconstructed in their di-muon decay channel in the rapidity interval 2.5 < y < 4.0 and over the transverse-momentum interval 2 < pT < 15 GeV/c. The three polarization parameters (lambda(theta), lambda(phi), lambda(theta phi)) are measured as a function of pT both in the helicity and Collins-Soper reference frames. The measured J/psi polarization parameters are found to be compatible with zero within uncertainties, contrary to expectations from all available predictions. The results are compared with the measurement in pp collisions at root s = 7 TeV.787116CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig
J/ψ-hadron correlations at midrapidity in pp collisions at √s=13 TeV
No full textWe report on the measurement of inclusive, non-prompt, and prompt J/ψ-hadron correlations by the ALICE Collaboration at the CERN Large Hadron Collider in pp collisions at a center-of-mass energy of 13 TeV. The correlations are studied at midrapidity (|y| < 0.9) in the transverse momentum ranges pT< 40 GeV/c for the J/ψ and 0.15 < pT< 10 GeV/c and |η| < 0.9 for the associated hadrons. The measurement is based on minimum bias and high multiplicity data samples corresponding to integrated luminosities of Lint = 34 nb−1 and Lint = 6.9 pb−1, respectively. In addition, two more data samples are employed, requiring, on top of the minimum bias condition, a threshold on the tower energy of E = 4 and 9 GeV in the ALICE electromagnetic calorimeters, which correspond to integrated luminosities of Lint = 0.9 pb−1 and Lint = 8.4 pb−1, respectively. The azimuthally integrated near and away side yields of associated charged hadrons per J/ψ trigger are presented as a function of the J/ψ and associated hadron transverse momentum. The measurements are discussed in comparison to PYTHIA calculations
MYH9-Related Thrombocytopenia: Four Novel Variants Affecting the Tail Domain of the Non-Muscle Myosin Heavy Chain IIA Associated with a Mild Clinical Evolution of the Disorder
No full textMYH9-related disease (MYH9-RD) is an autosomal-dominant thrombocytopenia caused by mutations in the gene for non-muscle myosin heavy chain IIA (NMMHC-IIA). Patients present congenital macrothrombocytopenia and inclusions of NMMHC-IIA in leukocytes, and have a variable risk of developing kidney damage, sensorineural deafness, presenile cataracts and/or liver enzymes abnormalities. The spectrum of mutations found in MYH9-RD patients is limited and the incidence and severity of the non-congenital features are predicted by the causative MYH9 variant. In particular, different alterations of the C-terminal tail domain of NMMHC-IIA associate with remarkably different disease evolution. We report four novel MYH9 mutations affecting the tail domain of NMMHC-IIA and responsible for MYH9-RD in four families. Two variants cause amino acid substitutions in the coiled-coil region of NMMHC-IIA, while the other two are a splicing variant and a single nucleotide deletion both resulting in frameshift alterations of the short non-helical tailpiece. Characterization of phenotypes of affected individuals shows that all of these novel variants are associated with a mild clinical evolution of the disease
Study of J/ψ azimuthal anisotropy at forward rapidity in Pb-Pb collisions at √sNN=5.02 TeV
No full textThe second (v2) and third (v3) flow harmonic coefficients of J/ψ mesons are measured at forward rapidity (2.5 < y < 4.0) in Pb-Pb collisions at √sNN = 5.02 TeV with the ALICE detector at the LHC. Results are obtained with the scalar product method and reported as a function of transverse momentum, pT, for various collision centralities. A positive value of J/ψ v3 is observed with 3.7σ significance. The measurements, compared to those of prompt D0 mesons and charged particles at mid-rapidity, indicate an ordering with vn(J/ψ) < vn(D0) < vn(h±) (n = 2, 3) at low and intermediate pT up to 6GeV/c and a convergence with v2(J/ψ) ≈ v2(D0) ≈ v2(h±) at high pT above 6–8 GeV/c. In semi- central collisions (5–40% and 10–50% centrality intervals) at intermediate pT between 2 and 6 GeV/c, the ratio v3/v2 of J/ψ mesons is found to be significantly lower (4.6σ) with respect to that of charged particles. In addition, the comparison to the prompt D0-meson ratio in the same pT interval suggests an ordering similar to that of the v2 and v3 coefficients. The J/ψ v2 coefficient is further studied using the Event Shape Engineering technique. The obtained results are found to be compatible with the expected variations of the eccentricity of the initial-state geometry
Prompt and non-prompt J/ψ production at midrapidity in Pb–Pb collisions at s NN = 5.02 TeV
No full textAbstract The transverse momentum (p T) and centrality dependence of the nuclear modification factor R AA of prompt and non-prompt J/ψ, the latter originating from the weak decays of beauty hadrons, have been measured by the ALICE collaboration in Pb–Pb collisions at s NN = 5.02 TeV. The measurements are carried out through the e+e − decay channel at midrapidity (|y| 5 GeV/c, which becomes stronger with increasing collision centrality. The results are consistent with similar LHC measurements in the overlapping p T intervals, and cover the kinematic region down to p T = 1.5 GeV/c at midrapidity, not accessible by other LHC experiments. The suppression of prompt J/ψ in central and semicentral collisions exhibits a decreasing trend towards lower transverse momentum, described within uncertainties by models implementing J/ψ production from recombination of c and c ¯ quarks produced independently in different partonic scatterings. At high transverse momentum, transport models including quarkonium dissociation are able to describe the suppression for prompt J/ψ. For non-prompt J/ψ, the suppression predicted by models including both collisional and radiative processes for the computation of the beauty-quark energy loss inside the quark-gluon plasma is consistent with measurements within uncertainties
Measurement of the production cross section of prompt baryons in p–Pb collisions at TeV
No full textThe transverse momentum (pT) differential production cross section of the promptly produced charm strange
baryon Csi_0c (and its charge conjugate anti_Csi_0c) is measured at midrapidity via its hadronic decay into π+ Sigma-
in p–Pb collisions at a centre-of-mass energy per nucleon–nucleon collision √sNN = 5.02 TeV with the ALICE detector at the LHC.
The Csi_0c nuclear modification factor (RpPb), calculated
from the cross sections in pp and p–Pb collisions, is
presented and compared with the RpPb of
+c
baryons. The
ratios between the pT-differential production cross section of
0c
baryons and those of D0 mesons and
+c
baryons are also
reported and compared with results at forward and backward
rapidity from the LHCb Collaboration. Themeasurements of
the production cross section of prompt 0c
baryons are compared
with a model based on perturbative QCD calculations
of charm-quark production cross sections, which includes
only cold nuclear matter effects in p–Pb collisions, and underestimates
the measurement by a factor of about 50. This discrepancy
is reduced when the data is compared with a model
that includes string formation beyond leading-colour approximation
or in which hadronisation is implemented via quark
coalescence. The pT-integrated cross section of prompt
0c
-baryon production at midrapidity extrapolated down to
pT = 0 is also reported. These measurements offer insights
and constraints for theoretical calculations of the hadronisation
process. Additionally, they provide inputs for the calculation
of the charm production cross section in p–Pb collisions
at midrapidity
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