7 research outputs found
Charged particle production in the Pb+Pb system at 158 GeV/c per nucleon
Charged particle multiplicities from high multiplicity central interactions
of 158 GeV/nucleon Pb ions with Pb target nuclei have been measured in the
central and far forward projectile spectator regions using emulsion chambers.
Multiplicities are significantly lower than predicted by Monte Carlo
simulations. We examine the shape of the pseudorapidity distribution and its
dependence on centrality in detail.Comment: 17 pages text plus 12 figures in postscript 12/23/99 -- Add TeX
version of sourc
Hadron and hadron-cluster production in a hydrodynamical model including particle evaporation
We discuss the evolution of the mixed phase at RHIC and SPS within
boostinvariant hydrodynamics. In addition to the hydrodynamical expansion, we
also consider evaporation of particles off the surface of the fluid. The
back-reaction of the evaporation process on the dynamics of the fluid shortens
the lifetime of the mixed phase. In our model this lifetime of the mixed phase
is <12 fm/c in Au+Au at RHIC and <6.5 fm/c in Pb+Pb at SPS, even in the limit
of vanishing transverse expansion velocity. Strangeness separation occurs,
especially in events (or at rapidities) with relatively high initial net baryon
and strangeness number, enhancing the multiplicity of MEMOs (multiply strange
nuclear clusters). If antiquarks and antibaryons reach saturation in the course
of the pure QGP or mixed phase, we find that at RHIC the ratio of antideuterons
to deuterons may exceed 0.3 and even anti-helium to helium>0.1. Due to
fluctuations, at RHIC even negative baryon number at midrapidity is possible in
individual events, so that the antibaryon and antibaryon-cluster yields exceed
those of the corresponding baryons and clusters.Comment: 17 pages, Latex, epsfig stylefil
Study of the transverse mass spectra of strange particles in Pb-Pb collisions at 158 A GeV/c
The NA57 experiment has collected high statistics, high purity samples of
\PKzS and \PgL, and hyperons produced in Pb-Pb collisions at 158
GeV/. In this paper we present a study of the transverse mass spectra of
these particles for a sample of events corresponding to the most central 53% of
the inelastic Pb-Pb cross-section. We analyse the transverse mass distributions
in the framework of the blast-wave model for the full sample and, for the first
time at the SPS, as a function of the event centrality.Comment: 22 pages, 14 figures, submitted to J. Phys. G: Nucl. Phy
Ankyrin is the major oxidised protein in erythrocyte membranes from end-stage renal disease patients on chronic haemodialysis and oxidation is decreased by dialysis and vitamin C supplementation
Chronically haemodialysed end-stage renal disease patients are at high risk of morbidity arising from complications of dialysis, the underlying pathology that has led to renal disease and the complex pathology of chronic kidney disease. Anaemia is commonplace and its origins are multifactorial, involving reduced renal erythropoietin production, accumulation of uremic toxins and an increase in erythrocyte fragility. Oxidative damage is a common risk factor in renal disease and its co-morbidities and is known to cause erythrocyte fragility. Therefore, we have investigated the hypothesis that specific erythrocyte membrane proteins are more oxidised in end-stage renal disease patients and that vitamin C supplementation can ameliorate membrane protein oxidation. Eleven patients and 15 control subjects were recruited to the study. Patients were supplemented with 2 Ă— 500 mg vitamin C per day for 4 weeks. Erythrocyte membrane proteins were prepared pre- and post-vitamin C supplementation for determination of protein oxidation. Total protein carbonyls were reduced by vitamin C supplementation but not by dialysis when investigated by enzyme linked immunosorbent assay. Using a western blot to detect oxidised proteins, one protein band, later identified as containing ankyrin, was found to be oxidised in patients but not controls and was reduced significantly by 60% in all patients after dialysis and by 20% after vitamin C treatment pre-dialysis. Ankyrin oxidation analysis may be useful in a stratified medicines approach as a possible marker to identify requirements for intervention in dialysis patients
Beneficial Effects of a Q-ter® Based Nutritional Mixture on Functional Performance, Mitochondrial Function, and Oxidative Stress in Rats
Mitochondrial dysfunction and oxidative stress are central mechanisms underlying the aging process and the pathogenesis of many age-related diseases. Selected antioxidants and specific combinations of nutritional compounds could target many biochemical pathways that affect both oxidative stress and mitochondrial function and, thereby, preserve or enhance physical performance. supplementation in rats at 29 months of age. supplementation may be particularly beneficial when initiated prior to major biological and functional declines that appear to occur with advancing age