467 research outputs found
Net charge fluctuation and string fragmentation
We present simulation results of net charge fluctuation in collisions
at =130 GeV from a dynamic model, JPCIAE. The calculations are
done for the quark-gluon phase before hadronization, the pion gas, the
resonance pion gas from and decays and so on. The simulations
of the charge fluctuation show that the discrepancy exists between the dynamic
model and the thermal model for a pion gas and a resonance pion gas from
and decays while the simulated charge fluctuation of the quark-gluon
phase is close to the thermal model prediction. JPCIAE results of net charge
fluctuation in the hardonic phase are nearly 4-5 times larger than one for the
quark-gluon phase, which implies that the charge fluctuation in the quark-gluon
phase may not survive the hadronization (string fragmentation) as implemented
in JPCIAE.Comment: 9 pages, 3 figure
Exotic mesons from quantum chromodynamics with improved gluon and quark actions on the anisotropic lattice
Hybrid (exotic) mesons, which are important predictions of quantum
chromodynamics (QCD), are states of quarks and anti-quarks bound by excited
gluons. First principle lattice study of such states would help us understand
the role of ``dynamical'' color in low energy QCD and provide valuable
information for experimental search for these new particles. In this paper, we
apply both improved gluon and quark actions to the hybrid mesons, which might
be much more efficient than the previous works in reducing lattice spacing
error and finite volume effect. Quenched simulations were done at
and on a anisotropic lattice using our PC cluster. We
obtain MeV for the mass of the hybrid meson
in the light quark sector, and Mev in the
charm quark sector; the mass splitting between the hybrid meson in the charm quark sector and the spin averaged S-wave charmonium mass
is estimated to be MeV. As a byproduct, we obtain MeV for the mass of a P-wave or
meson and MeV for the mass of a P-wave meson, which are comparable to their experimental value 1426 MeV for the
meson. The first error is statistical, and the second one is
systematical. The mixing of the hybrid meson with a four quark state is also
discussed.Comment: 12 pages, 3 figures. Published versio
Hybrid mesons from anisotropic lattice QCD with the clover and improved gauge actions
We study hybrid mesons from the clover and improved gauge actions at
on the anisotropic lattice using our PC cluster. We
estimate the mass of light quark hybrid as well as the mass of the
charmonium hybrid. The improvement of both quark and gluonic actions, first
applied to the hybrid mesons, is shown to be more efficient in reducing the
lattice spacing and finite volume errors.Comment: Lattice2002 (spectrum
Changes of plasma fibroblast growth factor-21 (FGF-21) in oral glucose tolerance test and effects of metformin on FGF-21 levels in type 2 diabetes mellitus
Wstęp: Badanie przeprowadzono w celu ustalenia, czy czynnik wzrostu fibroblastów-21 (FGF-21) uczestniczy w regulacji stężenia glukozy
i czy zastosowanie metforminy u chorych na cukrzycę wpływa na stężenie FGF-21.
Materiał i metody: Do badania włączono 43 osoby, w tym 27 chorych z nowo rozpoznaną cukrzycą typu 2 (nT2DM). U wszystkich przeprowadzono
test doustnego obciążenia 75 g glukozy (OGTT). Próbki krwi pobrano w 0., 60.,120. i 180. minucie testu. Osobom z nT2DM
zaproponowano udział w dalszych badaniach; zastosowano u nich metforminę w dawce 1,0 g/dobę przez tydzień.
Wyniki: Zmiany stężenia FGF-21 w osoczu podczas OGTT zaobserwowano tylko w grupie chorych na nT2DM; w grupie kontrolnej stężenie
FGF-21 pozostało niezmienione. Nie stwierdzono, by stężenia FGF-21 w poszczególnych punktach czasowych różniły się w zależności od płci
badanych (p < 0,05). Zastosowanie metforminy u osób z nT2DM spowodowało istotne zmniejszenie stężeń glukozy i FGF-21 we wszystkich
punktach czasowych OGTT oraz zmniejszenie stężenia insuliny w 60. i 180. minucie, co wskazuje na obniżenie wskaźnika HOMA-IR.
Wnioski: FGF-21 nie uczestniczy w krótkoterminowej regulacji glikemii u ludzi, a zmiany jego stężenia podczas OGTT są opóźnione
w T2DM. Być może FGF-21 bierze udział w metabolizowaniu metforminy, zwiększając wrażliwość na glukozę i insulinę.
(Endokrynol Pol 2013; 64 (3): 220–224)Introduction: The objectives of our study were to investigate whether fibroblast growth factor-21 (FGF-21) is involved in short-term
regulation of glucose and the change of FGF-21 after metformin use in diabetic subjects.
Material and methods: 43 subjects were recruited in the study, including 27 new-onset type 2 diabetes patients (nT2DM). A 75 g oral
glucose tolerance test (OGTT) was administered to them. Blood samples were taken at 0, 60 ,120 and 180 minute of OGTT. nT2DM subjects
were invited for further investigation, metformin was administered in a dose of 1.0 g every day for 1 week.
Results: Plasma FGF-21 changed significantly in the nT2DM group during the OGTT administration but not in the control group. No
gender differences were observed at different time points in FGF-21 levels (p < 0.05). Administration of metformin for nT2DM resulted
in a significant decrease in both glucose and FGF-21 at all OGTT times and in insulin at 60 min and 180 min, indicative of a decrease in
HOMA-IR.
Conclusion: FGF-21 does not seem to be involved in short-term regulation of glycaemia in human subjects, and the change in OGTT
delayed in T2DM. FGF-21 may participate in the processing of metformin, improving glucose and insulin sensitivity.
(Pol J Endocrinol 2013; 64 (3): 220–224
FY2014 Annual Report
Abstract Background This population-based study was designed to investigate whether consumption of sugar-sweetened beverages (SSB) is associated with lower serum total testosterone concentration in men 20–39 years old. Methods All data for this study were retrieved from the National Health and Nutrition Examination Survey (NHANES) 2011–2012. The primary outcome was serum testosterone concentration, and main independent variable was SSB intake. Other variables included age, race/ethnicity, poverty/income ratio, body mass index (BMI), serum cotinine, heavy drinking, and physical activity. Results Among all subjects (N = 545), 486 (90.4%) had normal testosterone levels (defined as ≥231 ng/dL) and 59 (9.6%) had low testosterone levels (defined as < 231 ng/dL). Multivariate logistic regression revealed the odds of low testosterone was significantly greater with increasing SSB consumption (Q4 [≥442 kcal/day] vs. Q1 [≤137 kcal/day]), adjusted odds ratio [aOR] = 2.29, p = 0.041]. After adjusting for possible confounding variables, BMI was an independent risk factor for low testosterone level; subjects with BMI ≥ 25 kg/m2 had a higher risk of having a low testosterone level than those with BMI < 25 kg/m2 (aOR = 3.68, p = 0.044). Conclusion SSB consumption is significantly associated with low serum testosterone in men 20–39 years old in the United States
Improving QCD with fermions: the 2 dimensional case of QCD with Sea Quarks
We study QCD in 2 dimensions using the improved lattice fermionic Hamiltonian
proposed by Luo, Chen, Xu and Jiang. The vector mass and the chiral condensate
are computed for various gauge groups. We do observe considerable
improvement in comparison with the Wilson quark case.Comment: LATTICE98(improvement
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