274 research outputs found
Recalculation of QCD Corrections to Decay
We give a more complete calculation of decay, including
leading log QCD corrections from to in addition to corrections
from to . We have included the full set of dimension-6 operators
and corrected numerical mistakes of anomalous dimensions in a previous
paper\cite{Cho}. Comparing with the calculations without QCD running from
to \cite{Mis}, the inclusive decay rate is found to be enhanced.
At GeV, it results in 12\% enhancement, and for GeV, 15\% is
found. The total QCD effect makes an enhanced factor of 4.2 at GeV,
and 3.2 for GeV.Comment: 16 pages, 7 figures (uuencoded ps files), Changes of description. To
appear in Phys. Rev.
Noble Gas (Argon and Xenon)-Saturated Cold Storage Solutions Reduce Ischemia-Reperfusion Injury in a Rat Model of Renal Transplantation
Background: Following kidney transplantation, ischemia-reperfusion injury contributes to adverse outcomes. The purpose of this study was to determine whether a cold-storage solution saturated with noble gas (xenon or argon) could limit ischemia-reperfusion injury following cold ischemia. Methods: Sixty Wistar rats were randomly allocated to 4 experimental groups. Kidneys were harvested and then stored for 6 h before transplantation in cold-storage solution (Celsior®) saturated with either air, nitrogen, xenon or argon. A syngenic orthotopic transplantation was performed. Renal function was determined on days 7 and 14 after transplantation. Transplanted kidneys were removed on day 14 for histological and immunohistochemical analyses. Results: Creatinine clearance was significantly higher and urinary albumin significantly lower in the argon and xenon groups than in the other groups at days 7 and 14. These effects were considerably more pronounced for argon than for xenon. In addition, kidneys stored with argon, and to a lesser extent those stored with xenon, displayed preserved renal architecture as well as higher CD-10 and little active caspase-3 expression compared to other groups. Conclusion: Argon- or xenon-satured cold-storage solution preserved renal architecture and function following transplantation by reducing ischemia-reperfusion injury
The littlest Higgs model and Higgs boson associated production with top quark pair at high energy linear collider
In the parameter space allowed by the electroweak precision measurement data,
we consider the contributions of the new particles predicted by the littlest
Higgs() model to the Higgs boson associated production with top quark pair
in the future high energy linear collider(). We find that the
contributions mainly come from the new gauge bosons and . For
reasonable values of the free parameters, the absolute value of the relative
correction parameter can be significanly large,
which might be observed in the future experiment with .Comment: latex files, 13 pages, 3 figure
Predictors of persistent diarrhea in norovirus enteritis after solid organ transplantation
Solid organ transplant (SOT) recipients may develop protracted diarrheal illness from norovirus. We performed a retrospective chart review between January 2010 and April 2014 to identify predictors of persistent diarrhea in transplant recipients with norovirus enteritis. A total of 152 SOT recipients with mean age of 31.5 years (SD 23.1) were included: 43.4% male, 34.2% pediatric patients. Allograft types were abdominal 136 (89.5%) (kidney [39.5%], liver-small bowel [23%], other [27%]) and thoracic 16 (10.5%). The median time to diagnosis of first norovirus enteritis episode from date of transplantation was 1.7 (0.3-5.3) years. At time of presentation, diarrhea was present in 141 (93%). Thirty percent had persistent diarrhea at 2 weeks. Hospitalization was required for treatment in 121 (80%) of episodes with the mean length of stay of 10±15.2 days. Most (91%) infections were due to norovirus genogroup II, and gastrointestinal coinfections were seen in 23 (19%) norovirus enteritis episodes. Nausea at time of diagnosis (P=.002) and cytomegalovirus (CMV) infection in the preceding 90 days (P=.036) were identified as independent risk factors for persistent diarrhea using univariate and multivariable logistic regression. Our study shows that nausea on presentation and prior CMV infection were associated with persistent diarrhea in patients with norovirus enteritis
Simultaneous Softening of sigma and rho Mesons associated with Chiral Restoration
Complex poles of the unitarized pi-pi scattering amplitude in nuclear matter
are studied. Partial restoration of chiral symmetry is modeled by the decrease
of in-medium pion decay constant f*_{pi}.
For large chiral restoration (f*_{pi}/f_{pi} << 1),
2nd sheet poles in the scalar (sigma) and the vector (rho) mesons are both
dictated by the Lambert W function and show universal softening as f*_{pi}
decreases.
In-medium pi-pi cross section receives substantial contribution from the soft
mode and exhibits a large enhancement in low-energy region.
Fate of this universality for small chiral restoration (f*_{pi}/f_{pi} ~ 1)
is also discussed.Comment: 5 pages, 4-eps figures, version accepted by Phys. Rev. C (R) with
minor modification
Clinical presentation and outcomes of norovirus infection in intestinal allograft compared to native intestine
Background: No data are available on clinical manifestations and course of norovirus gastroenteritis (NVE) in intestinal allograft (from intestinal and multivisceral transplant recipients, ITR) compared to native intestine (from other allograft recipients, nITR). Methods: This was a retrospective study of solid organ transplant recipients with NVE at two centers from January 1, 2010 to April 1, 2014. Chi-square, t-test, linear and logistic regression analyses were done to compare NVE in ITR vs nITR patients. Results: The ITR (45 patients) were compared to nITR (107 patients). ITR were younger (odds ratio [OR]=0.90; P<.0001), less likely to receive anti-lymphocyte induction therapy (OR=0.15; P<.0001), and had shorter time from transplant to NVE (OR=0.99; P=.008). On presentation ITR had less frequent nausea (OR=0.11; P<.0001) or vomiting (OR=0.36; P=.01), higher white blood cell count (OR=1.09; P=.001), and higher glomerular filtration rate (OR=1.02; P<.0001). ITR were less likely to receive anti-motility agents (OR=9.6; P<.0001). ITR were more likely to stay longer on intravenous (IV) fluids (OR=1.18; P<.0001); have recurrent NVE (OR=4.25; P<.0001); have longer hospital stay (OR=1.07; P<.0001); develop acute rejection (OR=5.1; P=.006); and have lower overall survival (OR=0.28; P=.006). Conclusions: Compared to nITR, the ITR with NVE were significantly younger, had less nausea and vomiting at presentation, received less anti-motility agents, required more IV fluids, and had longer hospital stay. A trend was seen for lower survival with NVE in ITR
Confirmation of Anomalous Dynamical Arrest in attractive colloids: a molecular dynamics study
Previous theoretical, along with early simulation and experimental, studies
have indicated that particles with a short-ranged attraction exhibit a range of
new dynamical arrest phenomena. These include very pronounced reentrance in the
dynamical arrest curve, a logarithmic singularity in the density correlation
functions, and the existence of `attractive' and `repulsive' glasses. Here we
carry out extensive molecular dynamics calculations on dense systems
interacting via a square-well potential. This is one of the simplest systems
with the required properties, and may be regarded as canonical for interpreting
the phase diagram, and now also the dynamical arrest. We confirm the
theoretical predictions for re-entrance, logarithmic singularity, and give the
first direct evidence of the coexistence, independent of theory, of the two
coexisting glasses. We now regard the previous predictions of these phenomena
as having been established.Comment: 15 pages,15 figures; submitted to Phys. Rev.
Pair production of the heavy leptons in future high energy linear e^{+}e^{-} colliders
The littlest Higgs model with T-parity predicts the existence of the T-odd
particles, which can only be produced in pair. We consider pair production of
the T-odd leptons in future high energy linear collider ().
Our numerical results show that, as long as the T-odd leptons are not too
heavy, they can be copiously produced and their possible signals might be
detected via the processes in future
experiments.Comment: Discussions added, typos and references correcte
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Free-electron laser results from the Advanced Test Accelerator
PALADIN is a 10.6-..mu..m FEL amplifier experiment operating at the Lawrence Livermore National Laboratory's Advanced Test Accelerator, an induction linear accelerator designed to produce a 45-MeV, 10-kA electron beam. With a 15-m long wiggler, PALADIN demonstrated 27 dB of exponential gain from a 14-kW input signal. With a 5-MW input signal, the amplifier saturated after 10 dB of gain. The exponentially growing signal in the unsaturated amplifier was clearly seen to be gain guided by the electron beam. 7 refs., 8 figs
Charm multiplicity and the branching ratios of inclusive charmless b quark decays in the general two-Higgs-doublet models
In the framework of general two-Higgs-doublet models, we calculate the
branching ratios of various inclusive charmless b decays by using the low
energy effective Hamiltonian including next-to-leading order QCD corrections,
and examine the current status and the new physics effects on the determination
of the charm multiplicity and semileptonic branching ratio .
Within the considered parameter space, the enhancement to the ratio due to the charged-Higgs penguins can be as large as a factor of 8 (3) in
the model III (II), while the ratio can be increased from
the standard model prediction of 2.49% to 4.91% (2.99%) in the model III (II).
Consequently, the value of and can be decreased simultaneously
in the model III. The central value of will be lowered slightly by
about 0.003, but the ratio can be reduced significantly from the
theoretical prediction of in the SM to , for GeV, respectively. We find that
the predicted and the measured now agree within roughly one
standard deviation after taking into account the effects of gluonic charged
Higgs penguins in the model III with a relatively light charged Higgs boson.Comment: 25 pages, Latex file, axodraw.sty, 6 figures. Final version to be
published in Phys.Rev.
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