924 research outputs found
Letter to the Editor: Proton Pump Inhibitors in Cirrhosis: A Marker of Morbid Conditions or a Cause of Mortality?
We read with interest the study by Nardelli et al., which adds to a growing literature on the potential ills of proton pump inhibitors (PPIs) in patients with cirrhosis. Their prospective design allowed for assessment of minimal hepatic encephalopathy (HE), and they reported that PPI use was independently associated with minimal HE, overt HE, and mortality. While we applaud the authors’ efforts, we are concerned about residual confounding that may have led to misinterpretation of mortality results
On centralizer algebras for spin representations
We give a presentation of the centralizer algebras for tensor products of
spinor representations of quantum groups via generators and relations. In the
even-dimensional case, this can be described in terms of non-standard
q-deformations of orthogonal Lie algebras; in the odd-dimensional case only a
certain subalgebra will appear. In the classical case q = 1 the relations boil
down to Lie algebra relations
Symmetric Hyperbolic System in the Self-dual Teleparallel Gravity
In order to discuss the well-posed initial value formulation of the
teleparallel gravity and apply it to numerical relativity a symmetric
hyperbolic system in the self-dual teleparallel gravity which is equivalent to
the Ashtekar formulation is posed. This system is different from the ones in
other works by that the reality condition of the spatial metric is included in
the symmetric hyperbolicity and then is no longer an independent condition. In
addition the constraint equations of this system are rather simpler than the
ones in other works.Comment: 8 pages, no figure
A search for deeply bound kaonic nuclear states
We have measured proton and neutron energy spectra by stopping negative kaons
on liquid helium4. Two distinct peak structures were found on both spectra,
which were assigned to the formation of new kinds of strange stribaryons. In
this paper, we summarize both results.Comment: 7 pages, 3 figures, HYP2003 conference proceeding
Medicare/medicaid insurance, rurality, and black race associated with provision of hepatocellular carcinoma treatment and survival
Background: Early treatment of hepatocellular carcinoma (HCC) is associated with improved survival, but many patients with HCC do not receive therapy. We aimed to examine factors associated with HCC treatment and survival among incident patients with HCC in a statewide cancer registry. Materials and Methods: All patients with HCC from 2003 through 2013 were identified in the North Carolina cancer registry. These patients were linked to insurance claims from Medicare, Medicaid, and large private insurers in North Carolina. Associations between prespecified covariates and more advanced HCC stage at diagnosis (ie, multifocal cancer), care at a liver transplant center, and provision of HCC treatment were examined using multivariate logistic regression. A Cox proportional hazards model was developed to assess the association between these factors and survival. Results: Of 1,809 patients with HCC, 53% were seen at a transplant center,90 days from diagnosis, with lower odds among those who were Black (adjusted odds ratio [aOR], 0.54; 95% CI, 0.39-0.74), had Medicare insurance (aOR, 0.35; 95% CI, 0.21-0.59), had Medicaid insurance (aOR, 0.46; 95% CI, 0.28-0.77), and lived in a rural area; odds of transplant center visits were higher among those who had prediagnosis alpha fetoprotein screening (aOR, 1.74; 95% CI, 1.35-2.23) and PCP and gastroenterology care (aOR, 1.66; 95% CI, 1.27-2.18). Treatment was more likely among patients who had prediagnosis gastroenterology care (aOR, 1.68; 95% CI, 0.98-2.86) and transplant center visits (aOR, 2.42; 95% CI, 1.74-3.36). Survival was strongly associated with age, cancer stage, cirrhosis complications, and receipt of HCC treatment. Individuals with Medicare (adjusted hazard ratio [aHR], 1.58; 95% CI, 1.20-2.09) and Medicaid insurance (aHR, 1.55; 95% CI, 1.17-2.05) had shorter survival than those with private insurance. Conclusions: In this population-based cohort of patients with HCC, Medicare/Medicaid insurance, rural residence, and Black race were associated with lower provision of HCC treatment and poorer survival. Efforts should be made to improve access to care for these vulnerable populations
Magnetic spin excitations in Mn doped GaAs : A model study
We provide a quantitative theoretical model study of the dynamical magnetic
properties of optimally annealed GaMnAs. This model has already
been shown to reproduce accurately the Curie temperatures for
GaMnAs. Here we show that the calculated spin stiffness are in
excellent agreement with those which were obtained from ab-initio based
studies. In addition, an overall good agreement is also found with available
experimental data. We have also evaluated the magnon density of states and the
typical density of states from which the "mobility edge", separating the
extended from localized magnon states, was determined. The power of the model
lies in its ability to be generalized for a broad class of diluted magnetic
semiconductor materials, thus it bridges the gap between first principle
calculations and model based studies.Comment: 5 pages, 5 figures, Text and some figures revised to match the
accepted versio
Annihilation vs. Decay: Constraining dark matter properties from a gamma-ray detection
Most proposed dark matter candidates are stable and are produced thermally in
the early Universe. However, there is also the possibility of unstable (but
long-lived) dark matter, produced thermally or otherwise. We propose a strategy
to distinguish between dark matter annihilation and/or decay in the case that a
clear signal is detected in gamma-ray observations of Milky Way dwarf
spheroidal galaxies with gamma-ray experiments. The sole measurement of the
energy spectrum of an indirect signal would render the discrimination between
these cases impossible. We show that by examining the dependence of the
intensity and energy spectrum on the angular distribution of the emission, the
origin could be identified as decay, annihilation, or both. In addition, once
the type of signal is established, we show how these measurements could help to
extract information about the dark matter properties, including mass,
annihilation cross section, lifetime, dominant annihilation and decay channels,
and the presence of substructure. Although an application of the approach
presented here would likely be feasible with current experiments only for very
optimistic dark matter scenarios, the improved sensitivity of upcoming
experiments could enable this technique to be used to study a wider range of
dark matter models.Comment: 29 pp, 8 figs; replaced to match published version (minor changes and
some new references
The Tissue-Engineered Vascular Graft-Past, Present, and Future
Cardiovascular disease is the leading cause of death worldwide, with this trend predicted to continue for the foreseeable future. Common disorders are associated with the stenosis or occlusion of blood vessels. The preferred treatment for the long-term revascularization of occluded vessels is surgery utilizing vascular grafts, such as coronary artery bypass grafting and peripheral artery bypass grafting. Currently, autologous vessels such as the saphenous vein and internal thoracic artery represent the gold standard grafts for small-diameter vessels (<6 mm), outperforming synthetic alternatives. However, these vessels are of limited availability, require invasive harvest, and are often unsuitable for use. To address this, the development of a tissue-engineered vascular graft (TEVG) has been rigorously pursued. This article reviews the current state of the art of TEVGs. The various approaches being explored to generate TEVGs are described, including scaffold-based methods (using synthetic and natural polymers), the use of decellularized natural matrices, and tissue self-assembly processes, with the results of various in vivo studies, including clinical trials, highlighted. A discussion of the key areas for further investigation, including graft cell source, mechanical properties, hemodynamics, integration, and assessment in animal models, is then presented
Hepatic arterioportal malformation in a dog - case report
ABSTRACT Arterioportal communications are complex hepatic vascular abnormalities. These are rarely seen in dogs and typically manifest as neurological, gastrointestinal, and developmental changes. This report describes clinical, laboratory and imaging findings associated with hepatic arterioportal malformation in a male Shih-Tzu dog aged 12 months. The diagnosis was achieved using computed tomographic angiography. The therapeutic approach selected consisted of palliative medical management (diuretics) combined with dietary protein restriction (3.6 g/100 kcal) provided by hepatic diet and gut activity modulation using lactulose. Surgical intervention was not recommended due to the complexity of vascular changes and portal hypertension. Despite initial clinical improvement, the patient died of disease-related complications seven months after diagnosis. Computed tomographic angiography was vital for accurate diagnosis and treatment selection, that needs to be more investigated
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