804 research outputs found
Chiral magnetic currents with QGP medium response in heavy ion collisions at RHIC and LHC energies
We calculate the electromagnetic current with a more realistic approach in
the RHIC and LHC energy regions in the article. We take the partons formation
time as the initial time of the magnetic field response of QGP medium. The
maximum electromagnetic current and the time-integrated current are two
important characteristics of the chiral magnetic effect (CME), which can
characterize the intensity and duration of fluctuations of CME. We consider the
finite frequency response of CME to a time-varying magnetic field, find a
significant impact from QGP medium feedback, and estimate the generated
electromagnetic current as a function of time, beam energy and impact
parameter.Comment: 10 pages, 12 figur
PPAR-γ in the Cardiovascular System
Peroxisome proliferator-activated receptor-γ (PPAR-γ), an essential transcriptional mediator of adipogenesis, lipid metabolism, insulin sensitivity, and glucose homeostasis, is increasingly recognized as a key player in inflammatory cells and in cardiovascular diseases (CVD) such as hypertension, cardiac hypertrophy, congestive heart failure, and atherosclerosis. PPAR-γ agonists, the thiazolidinediones (TZDs), increase insulin sensitivity, lower blood glucose, decrease circulating free fatty acids and triglycerides, lower blood pressure, reduce inflammatory markers, and reduce atherosclerosis in insulin-resistant patients and animal models. Human genetic studies on PPAR-γ have revealed that functional changes in this nuclear receptor are associated with CVD. Recent controversial clinical studies raise the question of deleterious action of PPAR-γ agonists on the cardiovascular system. These complex interactions of metabolic responsive factors and cardiovascular disease promise to be important areas of focus for the future
Direct monitoring pressure overload predicts cardiac hypertrophy in mice
Pressure overload (POL) is a classical model for studying cardiac hypertrophy, but there has been no direct measure of hemodynamics in a conscious ambulatory mouse model of POL. We used abdominal aortic constriction to produce POL and radiotelemetry to measure the blood pressure and heart rate for three weeks. The cardiac size correlated with the systolic pressure in the last week is better than other hemodynamic parameters. Cardiac fibrosis was more correlated to the cardiac size than to the systolic pressure. The expression of the cardiac genes that are typically associated with cardiac hypertrophy was correlated with both cardiac size and systolic pressure. In conclusion, the systolic pressure is the major determinant of cardiac hypertrophy in the murine POL model. In contrast, cardiac fibrosis shows the influence of other factors besides systolic pressure. The combination of the POL model with continuous direct measurements of hemodynamics represents a significant technological advance and will lead to an extended usefulness of POL methodologically.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58150/2/pm7_11_001.pd
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Lipodystrophy, Diabetes and Normal Serum Insulin in PPARγ-Deficient Neonatal Mice
Peroxisome proliferator activated receptor gamma (PPARγ) is a pleiotropic ligand activated transcription factor that acts in several tissues to regulate adipocyte differentiation, lipid metabolism, insulin sensitivity and glucose homeostasis. PPARγ also regulates cardiomyocyte homeostasis and by virtue of its obligate role in placental development is required for embryonic survival. To determine the postnatal functions of PPARγ in vivo we studied globally deficient neonatal mice produced by epiblast-restricted elimination of PPARγ. PPARγ-rescued placentas support development of PPARγ-deficient embryos that are viable and born in near normal numbers. However, PPARγ-deficient neonatal mice show severe lipodystrophy, lipemia, hepatic steatosis with focal hepatitis, relative insulin deficiency and diabetes beginning soon after birth and culminating in failure to thrive and neonatal lethality between 4 and 10 days of age. These abnormalities are not observed with selective PPARγ2 deficiency or with deficiency restricted to hepatocytes, skeletal muscle, adipocytes, cardiomyocytes, endothelium or pancreatic beta cells. These observations suggest important but previously unappreciated functions for PPARγ1 in the neonatal period either alone or in combination with PPARγ2 in lipid metabolism, glucose homeostasis and insulin sensitivity
Effects of PPARs Agonists on Cardiac Metabolism in Littermate and Cardiomyocyte-Specific PPAR-γ –Knockout (CM-PGKO) Mice
Understanding the molecular regulatory mechanisms controlling for myocardial lipid metabolism is of critical importance for the development of new therapeutic strategies for heart diseases. The role of PPARγ and thiazolidinediones in regulation of myocardial lipid metabolism is controversial. The aim of our study was to assess the role of PPARγ on myocardial lipid metabolism and function and differentiate local/from systemic actions of PPARs agonists using cardiomyocyte-specific PPARγ –knockout (CM-PGKO) mice. To this aim, the effect of PPARγ, PPARγ/PPARα and PPARα agonists on cardiac function, intra-myocyte lipid accumulation and myocardial expression profile of genes and proteins, affecting lipid oxidation, uptake, synthesis, and storage (CD36, CPT1MIIA, AOX, FAS, SREBP1-c and ADPR) was evaluated in cardiomyocyte-specific PPARγ –knockout (CM-PGKO) and littermate control mice undergoing standard and high fat diet (HFD). At baseline, protein levels and mRNA expression of genes involved in lipid uptake, oxidation, synthesis, and accumulation of CM-PGKO mice were not significantly different from those of their littermate controls. At baseline, no difference in myocardial lipid content was found between CM-PGKO and littermate controls. In standard condition, pioglitazone and rosiglitazone do not affect myocardial metabolism while, fenofibrate treatment significantly increased CD36 and CPT1MIIA gene expression. In both CM-PGKO and control mice submitted to HFD, six weeks of treatment with rosiglitazone, fenofibrate and pioglitazone lowered myocardial lipid accumulation shifting myocardial substrate utilization towards greater contribution of glucose. In conclusion, at baseline, PPARγ does not play a crucial role in regulating cardiac metabolism in mice, probably due to its low myocardial expression. PPARs agonists, indirectly protect myocardium from lipotoxic damage likely reducing fatty acids delivery to the heart through the actions on adipose tissue. Nevertheless a direct non- PPARγ mediated mechanism of PPARγ agonist could not be ruled out
HBV-Related Hepatocellular Carcinoma Susceptibility Gene KIF1B Is Not Associated with Development of Chronic Hepatitis B
A recent genome-wide association study has identified a new susceptibility locus, kinesin family member 1B gene (KIF1B), strongly associated with progression from chronic hepatitis B (CHB) to hepatitis B virus-related hepatocellular carcinoma (HCC) in Chinese population, this study was carried out to explore the role of the genetic variants in KIF1B in the development of chronic hepatitis B.Three KIF1B polymorphisms (rs8019, rs17401924, and rs17401966) were selected and genotyped in 473 CHB patients and 580 controls with no history of CHB. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression model. None of these three SNPs showed association with CHBs after adjusting for age and gender. Equivalence-based method analysis confirmed the absence of association. In the further haplotype analysis, three common haplotypes were observed in this study population, but no significant effect was also found for haplotypes in the progression to CHB.This study showed the new locus identified for HCC, KIF1B, was not associated with progression to CHB, implying distinct genetic susceptibility factor contributes to the progression from hepatitis B virus infection to HCC. Nevertheless, further comprehensive analyses are warranted to dissect the mechanism
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
Observation of decays into vector meson pairs , , and
Decays of to vector meson pairs , and
are observed for the first time using
\psip events accumulated at the BESIII detector at the BEPCII
collider. The branching fractions are measured to be , , and , for , , and ,
respectively. The observation of decays into a pair of vector
mesons , and indicates that the hadron
helicity selection rule is significantly violated in decays. In
addition, the measurement of gives the rate of doubly
OZI-suppressed decay. Branching fractions for and
decays into other vector meson pairs are also measured with improved precision.Comment: 4 pages, 2 figure
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