386 research outputs found
Nonvascularized human skin chronic allograft rejection.
A 65-year-old man had extensive burns of the lower legs in 1991, at the age of 40 years. He was treated by nonvascularized and de-epithelialized, allogeneic split-thickness skin allograft and cyclosporine monotherapy for 2 months. Ulcers developed between 10 and 25 years after transplantation and a surgical debridement on the lower extremities was required. Analyses of the removed tissue allografts showed chronic antibody-mediated and cellular rejection with extensive and dense fibrosis, and diffuse capillary C4d deposits. An anti-DRB1*08:01, donor-specific antibody was present. A unique clinical condition with late immunopathological features of human skin chronic allograft rejection is reported
Integer quantum Hall effect for hard-core bosons and a failure of bosonic Chern-Simons mean-field theories for electrons at half-filled Landau level
Field-theoretical methods have been shown to be useful in constructing simple
effective theories for two-dimensional (2D) systems. These effective theories
are usually studied by perturbing around a mean-field approximation, so the
question whether such an approximation is meaningful arises immediately. We
here study 2D interacting electrons in a half-filled Landau level mapped onto
interacting hard-core bosons in a magnetic field. We argue that an interacting
hard-core boson system in a uniform external field such that there is one flux
quantum per particle (unit filling) exhibits an integer quantum Hall effect. As
a consequence, the mean-field approximation for mapping electrons at
half-filling to a boson system at integer filling fails.Comment: 13 pages latex with revtex. To be published in Phys. Rev.
Application of B-splines to determining eigen-spectrum of Feshbach molecules
The B-spline basis set method is applied to determining the rovibrational
eigen-spectrum of diatomic molecules. A particular attention is paid to a
challenging numerical task of an accurate and efficient description of the
vibrational levels near the dissociation limit (halo-state and Feshbach
molecules). Advantages of using B-splines are highlighted by comparing the
performance of the method with that of the commonly-used discrete variable
representation (DVR) approach. Several model cases, including the Morse
potential and realistic potentials with 1/R^3 and 1/R^6 long-range dependence
of the internuclear separation are studied. We find that the B-spline method is
superior to the DVR approach and it is robust enough to properly describe the
Feshbach molecules. The developed numerical method is applied to studying the
universal relation of the energy of the last bound state to the scattering
length. We numerically illustrate the validity of the quantum-defect-theoretic
formulation of such a relation for a 1/R^6 potential.Comment: submitted to can j phys: Walter Johnson symposu
Simultaneous quantification of fentanyl, sufentanil, cefazolin, doxapram and keto-doxapram in plasma using liquid chromatography–tandem mass spectrometry
A simple and specific UPLC–MS/MS method was developed and validated for simultaneous quantification of fentanyl, sufentanil, cefazolin, doxapram and its active metabolite keto-doxapram. The internal standard was fentanyl-d5 for all analytes. Chromatographic separation was achieved with a reversed-phase Acquity UPLC HSS T3 column with a run-time of only 5.0 min per injected sample. Gradient elution was performed with a mobile phase consisting of ammonium acetate or formic acid in Milli-Q ultrapure water or in methanol with a total flow rate of 0.4 mL min−1. A plasma volume of only 50 μL was required to achieve adequate accuracy and precision. Calibration curves of all five analytes were linear. All analytes were stable for at least 48 h in the autosampler. The method was validated according to US Food and Drug Administration guidelines. This method allows quantification of fentanyl, sufentanil, cefazolin, doxapram and keto-doxapram, which is useful for research as we
Sugars of pearl millet [Pennisetum americanum (L.) Leeke] grains
The sugars in the grains of nine pearl millet cultivars were fractionated through a Biogel column. Five different sugars‘(stachyose, raffinose, sucrose, glucose, and fructose) were identified. Sucrose was predominant in all the cultivars. Raffinose content was high as compared to other cereals, and maltose was absen
Momentum--dependent nuclear mean fields and collective flow in heavy ion collisions
We use the Boltzmann-Uehling-Uhlenbeck model to simulate the dynamical
evolution of heavy ion collisions and to compare the effects of two
parametrizations of the momentum--dependent nuclear mean field that have
identical properties in cold nuclear matter. We compare with recent data on
nuclear flow, as characterized by transverse momentum distributions and flow
() variables for symmetric and asymmetric systems. We find that the precise
functional dependence of the nuclear mean field on the particle momentum is
important. With our approach, we also confirm that the difference between
symmetric and asymmetric systems can be used to pin down the density and
momentum dependence of the nuclear self consistent one--body potential,
independently. All the data can be reproduced very well with a
momentum--dependent interaction with compressibility K = 210 MeV.Comment: 15 pages in ReVTeX 3.0; 12 postscript figures uuencoded; McGill/94-1
Electronic polarization in pentacene crystals and thin films
Electronic polarization is evaluated in pentacene crystals and in thin films
on a metallic substrate using a self-consistent method for computing charge
redistribution in non-overlapping molecules. The optical dielectric constant
and its principal axes are reported for a neutral crystal. The polarization
energies P+ and P- of a cation and anion at infinite separation are found for
both molecules in the crystal's unit cell in the bulk, at the surface, and at
the organic-metal interface of a film of N molecular layers. We find that a
single pentacene layer with herring-bone packing provides a screening
environment approaching the bulk. The polarization contribution to the
transport gap P=(P+)+(P-), which is 2.01 eV in the bulk, decreases and
increases by only ~ 10% at surfaces and interfaces, respectively. We also
compute the polarization energy of charge-transfer (CT) states with fixed
separation between anion and cation, and compare to electroabsorption data and
to submolecular calculations. Electronic polarization of ~ 1 eV per charge has
a major role for transport in organic molecular systems with limited overlap.Comment: 10 revtex pages, 6 PS figures embedde
Gastric Marginal Zone B Cell Lymphoma of the Duodenum
Small bowel lymphomas of the extranodal type occur in the young and are characteristically associated with malabsorption syndrome. We present the case of an elderly in whom there was no malabsorption and the duodenal tumor was a gastric type marginal zone B cell lymphoma also known as gastric mucosa-associated lymphoid tissue (MALT) lymphoma. A 73-year-old woman presented to the emergency room with 2 weeks of general weakness, recurrent vomiting containing food particles and abdominal distension. She had been diagnosed with diabetic gastroparesis 4 years prior. CT of the abdomen and pelvis was suggestive of gastric outlet obstruction but no evidence of pancreatic or duodenal mass. Endoscopy and biopsy of the tumor obstructing the distal first part of the duodenum confirmed a gastric marginal MALT lymphoma. The patient's symptoms improved with radiotherapy. Gastric MALT lymphoma, an extranodal lymphoma primarily described in the stomach, can also present in the small bowel and is not associated with malabsorption
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