448 research outputs found
The Model for End-Stage Liver Disease 3.0: An Update Without Proven Accuracy
Cellular mechanisms in basic and clinical gastroenterology and hepatolog
Identification of a protein encoded in the EB-viral open reading frame BMRF2
Using monospecific rabbit sera against a peptide derived from a potential antigenic region of the Epstein-Barr viral amino acid sequence encoded in the open reading frame BMRF2 we could identify a protein-complex of 53/55 kDa in chemically induced B95-8, P3HR1 and Raji cell lines. This protein could be shown to be membrane-associated, as predicted by previous computer analysis of the secondary structure and hydrophilicity pattern, and may be a member of EBV-induced membrane proteins in lytically infected cells
A dynamical model for correlated two-pion-exchange in the pion-nucleon interaction
A microscopic model for the process is presented in the
meson exchange framework, which in the pseudophysical region agrees with
available quasiempirical information. The scalar () and vector ()
piece of correlated two--pion exchange in the pion--nucleon interaction is then
derived via dispersion integrals over the unitarity cut. Inherent ambiguities
in the method and implications for the description of pion--nucleon scattering
data are discussed.Comment: 20 pages, 11 postscript figure
Towards an understanding of isospin violation in pion-nucleon scattering
We investigate isospin breaking in low-energy pion-nucleon scattering in the
framework of chiral perturbation theory. This work extends the systematic
analysis of [1] to the energy range above threshold. Various relations, which
identically vanish in the limit of isospin symmetry, are used to quantify
isospin breaking effects. We study the energy dependence of the S- and P-wave
projections of these ratios and find dramatic effects in the S-waves of those
two relations which are given in terms of isoscalar quantities only. This
effect drops rather quickly with growing center-of-mass energy.Comment: 12 pp, REVTeX, 8 figs, FZJ-IKP(TH)-2000-2
Low Energy Pion-Hyperon Interaction
We study the low energy pion-hyperon interaction considering effective
non-linear chiral invariant Lagrangians including pions, rho mesons, hyperons
and corresponding resonances. Then we calculate the S- and P-wave phase-shifts,
total cross sections, angular distributions and polarizations for the momentum
in the center-of-mass frame up to k=400 MeV. With these results we discuss the
CP violation in the csi-> pi-lambda and omega-> pi-csi weak decays.Comment: 10 pages, 10 figure
\pi\pi, K\pi and \pi N potential scattering and a prediction of a narrow \sigma meson resonance
Low energy scattering and bound state properties of the \pi N, \pi\pi and
K\pi systems are studied as coupled channel problems using inversion potentials
of phase shift data. In a first step we apply the potential model to explain
recent measurements of pionic hydrogen shift and width. Secondly, predictions
of the model for pionium lifetime and shift confirm a well known and widely
used effective range expression. Thirdly, as extension of this confirmation, we
predict an unexpected medium effect of the pionium lifetime which shortens by
several orders of magnitude. The \sigma meson shows a narrow resonance
structure as a function of the medium modified mass with the implication of
being essentially energy independent. Similarly, we see this medium resonance
effect realized for the K\pi system. To support our findings we present also
results for the \rho meson and the \Delta(1232) resonance.Comment: 42 pages, 17 PS figures, REFTeX, epsfig.sty needed, submitted to
Phys. Re
Joint modeling of liver transplant candidates outperforms the model for end-stage liver disease: the effect of disease development over time on patient outcome
Liver function is measured regularly in liver transplantation (LT) candidates. Currently, these previous disease development data are not used for survival prediction. By constructing and validating joint models (JMs), we aimed to predict the outcome based on all available data, using both disease severity and its rate of change over time. Adult LT candidates listed in Eurotransplant between 2007 and 2018 (n = 16 283) and UNOS between 2016 and 2019 (n = 30 533) were included. Patients with acute liver failure, exception points, or priority status were excluded. Longitudinal MELD(-Na) data were modeled using spline-based mixed effects. Waiting list survival was modeled with Cox proportional hazards models. The JMs combined the longitudinal and survival analysis. JM 90-day mortality prediction performance was compared to MELD(-Na) in the validation cohorts. MELD(-Na) score and its rate of change over time significantly influenced patient survival. The JMs significantly outperformed the MELD(-Na) score at baseline and during follow-up. At baseline, MELD-JM AUC and MELD AUC were 0.94 (0.92-0.95) and 0.87 (0.85-0.89), respectively. MELDNa-JM AUC was 0.91 (0.89-0.93) and MELD-Na AUC was 0.84 (0.81-0.87). The JMs were significantly (p < .001) more accurate than MELD(-Na). After 90 days, we ranked patients for LT based on their MELD-Na and MELDNa-JM survival rates, showing that MELDNa-JM-prioritized patients had three times higher waiting list mortality.Transplant surger
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