1,016 research outputs found
Effects of propiverine and its metabolite propiverine-N-oxide on bladder contraction and salivation in mini pigs
Purpose: The objective of this study was to evaluate the influence of propiverine-HCl (P4) and propiverine-N-oxide (P4NO), one of the major metabolites of P4, on bladder contraction in a standardized in vivo model. Additionally, salivary flow measurements enabled the evaluation of hyposalivation, one of the most predominant anticholinergic side effects. Materials and Methods: Ten male mini pigs were anesthetized. P4 (0.4 mg/kg b.w.) and P4NO (0.422 mg/kg b.w.) were administered intravenously. Bladder contractions were induced through sacral anterior root stimulation and cystometrogram evaluation was performed. For stimulation-induced salivary flow measurements, the lingual nerve was exposed for neurostimulation. The effects of P4 and P4NO on stimulation-induced bladder contraction and salivation were evaluated in 5 mini pigs, respectively. Results: In all experiments, for each animal reproducible intravesical pressure values (Pves) were elicited during sacral anterior root stimulation before administration of the study drug. After administration of P4, Pves decreased by 64% whereas P4NO decreased Pves by 28%. Inhibition of salivary flow with P4 and P4NO was 71 and 32%, respectively. Directly following intravenous administration of P4, a short-term and reversible period of mild fluctuations in heart rate was observed. Administration of P4NO revealed no changes in either heart rate, or blood pressure. Conclusion: All of the investigated parameters revealed less anticholinergic effects for P4NO compared to P4. Under the experimental conditions described above, it may be assumed that P4NO behaves as a substance with poor anticholinergic effects with respect to side effects. As expected, P4 showed anticholinergic effects on bladder contraction and salivation. Copyrigh
Chiral-symmetry restoration in the linear sigma model at nonzero temperature and baryon density
We study the chiral phase transition in the linear sigma model with 2 quark
flavors and colors. One-loop calculations predict a first-order phase
transition at both and . We also discuss the phase diagram
and make a comparison with a thermal parametrization of existing heavy-ion
experimental data.Comment: 12 pages, 6 ps-figures, LaTe
Biologic Therapy for HLA-B27-associated Ocular Disorders
The treatment of articular and extra-articular manifestations associated with HLA-B27 has undergone dramatic changes over the past two decades, mainly as a consequence of the introduction of biologic agents and in particular anti-tumor necrosis factor α (anti-TNFα) agents. Uveitis is known to be the most frequent extra-articular feature in HLA-B27-associated spondyloarthritides. Topical corticosteroids and cycloplegic agents remain the cornerstones of treatment. However, biologic therapy may be effective in the management of refractory or recurrent forms of uveitis. This review gives an update on the management of HLA-B27-associated ocular disorders with biologics, including anti-TNFα agents and non-anti-TNFα biologic modifier drugs. There is an emerging role for newer biologics targeting interleukin-12/23 and interleukin-17 for the treatment of spondyloarthritides but data on their efficacy on anterior uveitis are sparse
Hexagonal dielectric resonators and microcrystal lasers
We study long-lived resonances (lowest-loss modes) in hexagonally shaped
dielectric resonators in order to gain insight into the physics of a class of
microcrystal lasers. Numerical results on resonance positions and lifetimes,
near-field intensity patterns, far-field emission patterns, and effects of
rounding of corners are presented. Most features are explained by a
semiclassical approximation based on pseudointegrable ray dynamics and boundary
waves. The semiclassical model is also relevant for other microlasers of
polygonal geometry.Comment: 12 pages, 17 figures (3 with reduced quality
Lifetimes of electrons in the Shockley surface state band of Ag(111)
We present a theoretical many-body analysis of the electron-electron (e-e)
inelastic damping rate of electron-like excitations in the Shockley
surface state band of Ag(111). It takes into account ab-initio band structures
for both bulk and surface states. is found to increase more rapidly as
a function of surface state energy E than previously reported, thus leading to
an improved agreement with experimental data
Vibrations of a chain of Xe atoms in a groove of carbon nanotube bundle
We present a lattice dynamics study of the vibrations of a linear chain of Xe
adsorbates in groove positions of a bundle of carbon nanotubes. The
characteristic phonon frequencies are calculated and the adsorbate polarization
vectors discussed. Comparison of the present results with the ones previously
published shows that the adsorbate vibrations cannot be treated as completely
decoupled from the vibrations of carbon nanotubes and that a significant
hybridization between the adsorbate and the tube modes occurs for phonons of
large wavelengths.Comment: 3 PS figure
Double-Scaling Limit of Heterotic Bundles and Dynamical Deformation in CFT
We consider heterotic string theory on Eguchi-Hanson space, as a local model
of a resolved A_1 singularity in a six-dimensional flux compactification, with
an Abelian gauge bundle turned on and non-zero torsion. We show that in a
suitable double scaling limit, that isolates the physics near the non-vanishing
two-cycle, a worldsheet conformal field theory description can be found. It
contains a heterotic coset whose target space is conformal to Eguchi-Hanson.
Starting from the blow-down limit of the singularity, it can be viewed as a
dynamical deformation of the near-horizon fivebrane background. We analyze in
detail the spectrum of the theory in particular examples, as well as the
important role of worldsheet non-perturbative effects.Comment: 45 pages, no figures; ver2: typos corrected, references added, an
extra tadpole-free model covere
Electroproduction of two light vector mesons in next-to-leading BFKL: study of systematic effects
The forward electroproduction of two light vector mesons is the first example
of a collision process between strongly interacting colorless particles for
which the amplitude can be written completely within perturbative QCD in the
Regge limit with next-to-leading accuracy. In a previous paper we have given a
numerical determination of the amplitude in the case of equal photon
virtualities by using a definite representation for the amplitude and a
definite optimization method for the perturbative series. Here we estimate the
systematic uncertainty of our previous determination, by considering a
different representation of the amplitude and different optimization methods of
the perturbative series. Moreover, we compare our result for the differential
cross section at the minimum momentum transfer with a different approach, based
on collinear kernel improvement.Comment: 17 pages, 11 figures; journal version, new figures and discussion
adde
Influence of a Uniform Current on Collective Magnetization Dynamics in a Ferromagnetic Metal
We discuss the influence of a uniform current, , on the
magnetization dynamics of a ferromagnetic metal. We find that the magnon energy
has a current-induced contribution proportional to
, where is the spin-current, and
predict that collective dynamics will be more strongly damped at finite . We obtain similar results for models with and without local moment
participation in the magnetic order. For transition metal ferromagnets, we
estimate that the uniform magnetic state will be destabilized for . We discuss the relationship of this effect to
the spin-torque effects that alter magnetization dynamics in inhomogeneous
magnetic systems.Comment: 12 pages, 2 figure
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