1,315 research outputs found
Long-term quantitative hepatitis B surface antigen (HBsAg) trajectories in persons with and without HBsAg loss on tenofovir-containing antiretroviral therapy
OBJECTIVES
Improving the understanding of the patterns of quantitative hepatitis B surface antigen (qHBsAg) trajectories associated with HBsAg loss is important in light of novel anti-hepatitis B virus agents being developed. We evaluated long-term qHBsAg trajectories in persons with HIV and HBV during tenofovir-containing antiretroviral therapy in the Swiss HIV Cohort Study.
METHODS
We included 29 participants with and 29 without HBsAg loss, defined as qHBsAg <0.05 IU/mL. We assessed qHBsAg decline during therapy in both groups and used agglomerative hierarchical clustering to identify different qHBsAg trajectory profiles in persons with HBsAg loss.
RESULTS
The median follow-up time was 11.9 years (IQR 8.4-14.1), and the median time to HBsAg loss was 48 months (IQR 12-96). Among participants with HBsAg loss, 79% had a qHBsAg decline ≥1 log IU/mL 2 years after starting tenofovir. The trajectories in qHBsAg levels during tenofovir therapy were heterogeneous, characterized by five distinct profiles. Among participants without HBsAg loss, only 7% had a qHBsAg decline ≥1 log IU/ml after 2 years.
CONCLUSIONS
Most persons with HIV who experienced HBsAg loss had an early decline in qHBsAg levels, with diverse trajectories during long-term tenofovir therapy. In persons without HBsAg loss, qHBsAg levels remained remarkably stable over time
Control of Campylobacter spp. and Yersinia enterocolitica by virulent bacteriophages
The efficacy of the Campylobacter (C.) phages NCTC12684 (group II) and CP81
(group III) and of the Yersinia (Y.) phage PY100 to reduce the numbers of
Campylobacter and Y. enterocolitica in meat at 4(o)C applying different
Multiplicities of Infection (MOIs) was analyzed. Initial experiments were
carried out in broth at 4(o)C and 37(o)C to compare cell number reductions
under chilling and optimized growth conditions, respectively. The results
showed a 1 log(10) unit reduction of Campylobacter cell numbers at 37(o)C in
broth. However, no reduction was observed in broth and meat at 4(o)C. In
contrast, Y. enterocolitica cell numbers were reduced in broth at 4(o)C (up to
3 log(10) units after 24hr) and 37(o)C (5 log(10) units after 1.5hr) and also
in meat at 4(o)C (2 log(10) units after 48hr). The highest cell number
reductions were obtained at the highest MOIs
Deoxynivalenol, but not fumonisin B1, aflatoxin B1 or diesel exhaust particles disrupt integrity of the horse's respiratory epithelium and predispose it for equine herpesvirus type 1 infection
The horse's respiratory tract daily encounters a plethora of respirable hazards including air pollutants, mycotoxins and airborne pathogens. To date, the precise effect of air pollution and mycotoxins on respiratory epithelial integrity and subsequent pathogen invasion in the horse has not been studied. Here, diesel exhaust particles (DEP) and three major mycotoxins (deoxynivalenol [DON], aflatoxin B1 [AFB1] and fumonisin B1 [FB1]) were applied to the apical surfaces of both ex vivo respiratory mucosal explants and in vitro primary equine respiratory epithelial cells (EREC) cultivated at the air-liquid interface, prior to inoculation with equine herpesvirus type 1 (EHV1). DON, but not AFB1, FB1 and DEP affected epithelial integrity in both ex vivo and in vitro systems, as demonstrated by histological changes in respiratory epithelial morphology and a drop in transepithelial electrical resistance across the EREC monolayer. Further, DON-pretreated explants showed on average 6.5 +/- 4.5-fold more EHV1 plaques and produced on average 1 log(10) more extracellular virus particles compared to control diluent- and FB1-pretreated respiratory mucosal explants. Similarly, EHV1 infection was greatly enhanced in EREC upon pretreatment with DON. Based on our findings, we propose that inhalation of DON predisposes horses for EHV1 infection by affecting respiratory epithelial integrity
Effective Edwards-Wilkinson equation for single-file diffusion
In this work, we present an effective discrete Edwards-Wilkinson equation
aimed to describe the single-file diffusion process. The key physical
properties of the system are captured defining an effective elasticity, which
is proportional to the single particle diffusion coefficient and to the inverse
squared mean separation between particles. The effective equation gives a
description of single-file diffusion using the global roughness of the system
of particles, which presents three characteristic regimes, namely normal
diffusion, subdiffusion and saturation, separated by two crossover times. We
show how these regimes scale with the parameters of the original system.
Additional repulsive interaction terms are also considered and we analyze how
the crossover times depend on the intensity of the additional terms. Finally,
we show that the roughness distribution can be well characterized by the
Edwards-Wilkinson universal form for the different single-file diffusion
processes studied here.Comment: 9 pages, 9 figure
Spectral Energy Distributions of Gamma Ray Bursts Energized by External Shocks
Sari, Piran, and Narayan have derived analytic formulas to model the spectra
from gamma-ray burst blast waves that are energized by sweeping up material
from the surrounding medium. We extend these expressions to apply to general
radiative regimes and to include the effects of synchrotron self-absorption.
Electron energy losses due to the synchrotron self-Compton process are also
treated in a very approximate way. The calculated spectra are compared with
detailed numerical simulation results. We find that the spectral and temporal
breaks from the detailed numerical simulation are much smoother than the
analytic formulas imply, and that the discrepancies between the analytic and
numerical results are greatest near the breaks and endpoints of the synchrotron
spectra. The expressions are most accurate (within a factor of ~ 3) in the
optical/X-ray regime during the afterglow phase, and are more accurate when
epsilon_e, the fraction of swept-up particle energy that is transferred to the
electrons, is <~ 0.1. The analytic results provide at best order-of-magnitude
accuracy in the self-absorbed radio/infrared regime, and give poor fits to the
self-Compton spectra due to complications from Klein-Nishina effects and
photon-photon opacity.Comment: 16 pages, 7 figures, ApJ, in press, 537, July 1, 2000. Minor changes
in response to referee report, corrected figure
Distillation of Greenberger-Horne-Zeilinger states by combinatorial methods
We prove a lower bound on the rate of Greenberger-Horne-Zeilinger states
distillable from pure multipartite states by local operations and classical
communication (LOCC). Our proof is based on a modification of a combinatorial
argument used in the fast matrix multiplication algorithm of Coppersmith and
Winograd. Previous use of methods from algebraic complexity in quantum
information theory concerned transformations with stochastic local operations
and classical operation (SLOCC), resulting in an asymptotically vanishing
success probability. In contrast, our new protocol works with asymptotically
vanishing error.Comment: 26 pages, 2 figures; v2: updated to match published versio
Supersymmetry Without Prejudice at the LHC
The discovery and exploration of Supersymmetry in a model-independent fashion
will be a daunting task due to the large number of soft-breaking parameters in
the MSSM. In this paper, we explore the capability of the ATLAS detector at the
LHC ( TeV, 1 fb) to find SUSY within the 19-dimensional
pMSSM subspace of the MSSM using their standard transverse missing energy and
long-lived particle searches that were essentially designed for mSUGRA. To this
end, we employ a set of k previously generated model points in the
19-dimensional parameter space that satisfy all of the existing experimental
and theoretical constraints. Employing ATLAS-generated SM backgrounds and
following their approach in each of 11 missing energy analyses as closely as
possible, we explore all of these k model points for a possible SUSY
signal. To test our analysis procedure, we first verify that we faithfully
reproduce the published ATLAS results for the signal distributions for their
benchmark mSUGRA model points. We then show that, requiring all sparticle
masses to lie below 1(3) TeV, almost all(two-thirds) of the pMSSM model points
are discovered with a significance in at least one of these 11 analyses
assuming a 50\% systematic error on the SM background. If this systematic error
can be reduced to only 20\% then this parameter space coverage is increased.
These results are indicative that the ATLAS SUSY search strategy is robust
under a broad class of Supersymmetric models. We then explore in detail the
properties of the kinematically accessible model points which remain
unobservable by these search analyses in order to ascertain problematic cases
which may arise in general SUSY searches.Comment: 69 pages, 40 figures, Discussion adde
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