981 research outputs found
Pentoxifylline Plus Prednisolone versus Pentoxifylline Only for Severe Alcoholic Hepatitis: A Randomized Controlled Clinical Trial
Background: Prednisolone and pentoxifylline (PTX) have been shown to be individually useful in severe alcoholic hepatitis with Maddrey discriminant function (MDF) score .32. Previous report suggests that PTX is probably superior to prednisolone alone. However the efficacy of PTX and prednisolone combination over PTX alone in the management of acute alcoholic hepatitis (MDF score ≥32) is yet unrevealed.Aim: The present study was initiated to find out the efficacy of combined pentoxifylline and prednisolone versus PTX alone in acute alcoholic hepatitis in respect of short and intermediate term outcomes.Subjects and Methods: A total of 124 patients with severe alcoholic hepatitis (MDF score ≥32) initially were evaluated. 62 patients who fulfilled the inclusion and exclusion criteria were randomized and divided into 2 groups. Group 1 received PTX only, whereas Group 2 received PTX plus Prednisolone. The total duration of follow-up was 12 months. Studentfs t-test, Chi-square test, the Kaplan-Meier methods were used forstatistical analysis. Results: A total of 60 patients, 30 in each group were available for finalanalysis. In Group-1, 6 patients expired at the end of 1 year (5 within 3 months and another after 3 months). In Group 2, 10 patients expired at the end of 1 year (9 within 3 months and another after 3 months). Though survival probability is higher among Group 1 patients but the difference is not statistically significant.Conclusion: The combination of PTX plus Prednisolone yields no additional benefit in terms of mortality and morbidity from that of PTX monotherapy.Keywords: Alcoholic hepatitis, Maddrey discriminant function score, Pentoxifylline, Prednisolon
Higher-Energy Composite Fermion Levels in the Fractional Quantum Hall Effect
Even though composite fermions in the fractional quantum Hall liquid are well established, it is not yet known up to what energies they remain intact. We probe the high-energy spectrum of the 1/3 liquid directly by resonant inelastic light scattering, and report the observation of a large number of new collective modes. Supported by our theoretical calculations, we associate these with transitions across two or more composite fermions levels. The formation of quasiparticle levels up to high energies is direct evidence for the robustness of topological order in the fractional quantum Hall effect
Spiky Strings and Giant Holes
We analyse semiclassical strings in AdS in the limit of one large spin. In
this limit, classical string dynamics is described by a finite number of
collective coordinates corresponding to spikes or cusps of the string. The
semiclassical spectrum consists of two branches of excitations corresponding to
"large" and "small" spikes respectively. We propose that these states are dual
to the excitations known as large and small holes in the spin chain description
of N=4 SUSY Yang-Mills. The dynamics of large spikes in classical string theory
can be mapped to that of a classical spin chain of fixed length. In turn, small
spikes correspond to classical solitons propagating on the background formed by
the large spikes. We derive the dispersion relation for these excitations
directly in the finite gap formalism.Comment: 36 pages, 9 figure
Back-reaction of Non-supersymmetric Probes: Phase Transition and Stability
We consider back-reaction by non-supersymmetric D7/anti-D7 probe branes in
the Kuperstein-Sonnenschein model at finite temperature. Using the smearing
technique, we obtain an analytical solution for the back-reacted background to
leading order in N_f/N_c. This back-reaction explicitly breaks the conformal
invariance and introduces a dimension 6 operator in the dual field theory which
is an irrelevant deformation of the original conformal field theory. We further
probe this back-reacted background by introducing an additional set of probe
brane/anti-brane. This additional probe sector undergoes a chiral phase
transition at finite temperature, which is absent when the back-reaction
vanishes. We investigate the corresponding phase diagram and the thermodynamics
associated with this phase transition. We also argue that additional probes do
not suffer from any instability caused by the back-reaction, which suggests
that this system is stable beyond the probe limit.Comment: 56 pages, 8 figures. References updated, improved discussion on
dimension eight operato
Higher spin quasinormal modes and one-loop determinants in the BTZ black hole
We solve the wave equations of arbitrary integer spin fields in the BTZ black
hole background and obtain exact expressions for their quasinormal modes. We
show that these quasinormal modes precisely agree with the location of the
poles of the corresponding two point function in the dual conformal field
theory as predicted by the AdS/CFT correspondence. We then use these
quasinormal modes to construct the one-loop determinant of the higher spin
field in the thermal BTZ background. This is shown to agree with that obtained
from the corresponding heat kernel constructed recently by group theoretic
methods.Comment: 47 page
Thermodynamics of Large N Gauge Theories with Chemical Potentials in a 1/D Expansion
In order to understand thermodynamical properties of N D-branes with chemical
potentials associated with R-symmetry charges, we study a one dimensional large
N gauge theory (bosonic BFSS type model) as a first step. This model is
obtained through a dimensional reduction of a 1+D dimensional SU(N) Yang-Mills
theory and we use a 1/D expansion to investigate the phase structure. We find
three phases in the \mu-T plane. We also show that all the adjoint scalars
condense at large D and obtain a mass dynamically. This dynamical mass protects
our model from the usual perturbative instability of massless scalars in a
non-zero chemical potential. We find that the system is at least meta-stable
for arbitrary large values of the chemical potentials in D \to \infty limit. We
also explore the existence of similar condensation in higher dimensional gauge
theories in a high temperature limit. In 2 and 3 dimensions, the condensation
always happens as in one dimensional case. On the other hand, if the dimension
is higher than 4, there is a critical chemical potential and the condensation
happens only if the chemical potentials are below it.Comment: 37 pages, 4 figures; v2: minor corrections, references added; v3:
minor corrections, to appear in JHE
Knotting and unknotting of a protein in single molecule experiments.
Spontaneous folding of a polypeptide chain into a knotted structure remains one of the most puzzling and fascinating features of protein folding. The folding of knotted proteins is on the timescale of minutes and thus hard to reproduce with atomistic simulations that have been able to reproduce features of ultrafast folding in great detail. Furthermore, it is generally not possible to control the topology of the unfolded state. Single-molecule force spectroscopy is an ideal tool for overcoming this problem: by variation of pulling directions, we controlled the knotting topology of the unfolded state of the 52-knotted protein ubiquitin C-terminal hydrolase isoenzyme L1 (UCH-L1) and have therefore been able to quantify the influence of knotting on its folding rate. Here, we provide direct evidence that a threading event associated with formation of either a 31 or 52 knot, or a step closely associated with it, significantly slows down the folding of UCH-L1. The results of the optical tweezers experiments highlight the complex nature of the folding pathway, many additional intermediate structures being detected that cannot be resolved by intrinsic fluorescence. Mechanical stretching of knotted proteins is also of importance for understanding the possible implications of knots in proteins for cellular degradation. Compared with a simple 31 knot, we measure a significantly larger size for the 52 knot in the unfolded state that can be further tightened with higher forces. Our results highlight the potential difficulties in degrading a 52 knot compared with a 31 knot.N.C.H.L. is supported by a UBD Chancellor’s Scholarship from the Brunei Government. W.N. was supported by the Ministry of Education (MoE) Singapore. S.S.M acknowledges funding from the Alexander von Humboldt Foundation. This work was supported by an SFB 863 A2 grant of Deutsche Forschungsgemeinschaft to M.R
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