793 research outputs found
Long-term outcome of noninvasive positive pressure ventilation for obesity hypoventilation syndrome
BACKGROUND: Few data are available on the long-term outcome of noninvasive positive pressure ventilation (NPPV) for obesity hypoventilation syndrome (OHS). This study was designed to determine long-term survival, treatment adherence, and prognostic factors in patients with OHS in whom NPPV was initiated in an acute setting vs under stable clinical conditions.METHODS: One hundred thirty consecutive patients with OHS (56 women) who started NPPV between January 1995 and December 2006 either under stable conditions (stable group, n = 92) or during ICU management of acute hypercapnic exacerbation (acute group, n = 38) were retrospectively analyzed. RESULTS: Arterial blood gases and the Epworth sleepiness scale were both significantly improved after 6 months of NPPV. With a mean follow-up of 4.1 +/- 2.9 years, 24 (18.5%) patients died and 24 (18.5%) discontinued NPPV. On Kaplan-Meier analysis, 1-, 2-, 3-, and 5-year survival probabilities were 97.5%, 93%, 88.3%, and 77.3%, respectively. Mortality was lower than that described in a previous series of patients with untreated OHS. Supplemental oxygen therapy was the only independent predictor of mortality. The probability of continuing NPPV was 80% at 3 years with a high rate of daily use ( > 7 h). Female sex was predictive of lower long-term adherence to NPPV. The acute and stable groups did not differ in terms of arterial blood gases and Epworth sleepiness scale at 6 months, long-term survival, and treatment adherence. CONCLUSIONS: The results of this study support long-term NPPV as an effective and well-tolerated treatment of OHS whether initiated in the acute or chronic setting
Pneumopathie médicamenteuse sous traitement par venlafaxine et propranolol
Introduction
Venlafaxine and propranolol have rarely been identified as causes of pulmonary pathology. We describe a case of drug-induced pneumonitis occurring in a patient treated with these two medications.
Case report
A 55 years old woman with liver cirrhosis treated with venlafaxine for 1 year and propranolol for 1 month was admitted to the intensive care unit because of acute respiratory failure. A Mycoplasma pneumoniae pneumonitis was diagnosed. After initial improvement under antibiotics, a new deterioration of respiratory status was observed 4 days after the reintroduction of venlafaxine and propranolol. Spontaneous recovery occurred after these treatments were withheld. Co administration of venlafaxine and propranolol, 2 drugs with affinity for the same cytochrome P450 isoenzyme (CYP2D6), may have contributed to drug accumulation and pulmonary toxicity. The liver cirrhosis of our patient may also have contributed to decreased cytochrome P450 enzymatic activity.
Conclusions
Venlafaxine and propranolol share the same metabolic pathway and their co-administration may be complicated by drug induced pneumonitis
New Spins for ground states and isomers in Pd and Pd
Levels in 115Pd and 117Pd nuclei, populated in the spontaneous fission of 248Cm were studied by means of prompt gamma spectroscopy using the EUROGAM2 array of Anti-Compton spectrometers. Negative-parity, I = 9/2 excitations were identified, which are associated with the long-lived isomers in these nuclei, reported previously as 11/2- excitations. The new data indicate spin and parity 3/2 + for ground states in 115Pd and 117Pd instead of 5/2 + proposed in previous works. This result implicates changes of spin assignments to other levels in both nuclei
Hartree-Fock-Bogoliubov theory versus local-density approximation for superfluid trapped fermionic atoms
We investigate a gas of superfluid fermionic atoms trapped in two hyperfine
states by a spherical harmonic potential. We propose a new regularization
method to remove the ultraviolet divergence in the Hartree-Fock-Bogoliubov
equations caused by the use of a zero-range atom-atom interaction. Compared
with a method used in the literature, our method is simpler and has improved
convergence properties. Then we compare Hartree-Fock-Bogoliubov calculations
with the semiclassical local-density approximation. We observe that for systems
containing a small number of atoms shell effects, which cannot be reproduced by
the semiclassical calculation, are very important. For systems with a large
number of atoms at zero temperature the two calculations are in quite good
agreement, which, however, is deteriorated at non-zero temperature, especially
near the critical temperature. In this case the different behavior can be
explained within the Ginzburg-Landau theory.Comment: 12 pages, 8 figures, revtex; v2: references and clarifying remarks
adde
Interacting Ghost Dark Energy in Non-Flat Universe
A new dark energy model called "ghost dark energy" was recently suggested to
explain the observed accelerating expansion of the universe. This model
originates from the Veneziano ghost of QCD. The dark energy density is
proportional to Hubble parameter, , where is a
constant of order and is
QCD mass scale. In this paper, we extend the ghost dark energy model to the
universe with spatial curvature in the presence of interaction between dark
matter and dark energy. We study cosmological implications of this model in
detail. In the absence of interaction the equation of state parameter of ghost
dark energy is always and mimics a cosmological constant in the
late time, while it is possible to have provided the interaction is
taken into account. When , all previous results of ghost dark energy in
flat universe are recovered. To check the observational consistency, we use
Supernova type Ia (SNIa) Gold sample, shift parameter of Cosmic Microwave
Background radiation (CMB) and the Baryonic Acoustic Oscillation peak from
Sloan Digital Sky Survey (SDSS). The best fit values of free parameter at
confidence interval are: ,
and . Consequently
the total energy density of universe at present time in this model at 68% level
equates to .Comment: 19 pages, 9 figures. V2: Added comments, observational consequences,
references, figures and major corrections. Accepted for publication in
General Relativity and Gravitatio
On Dark Matter Annihilation in the Local Group
Under the hypothesis of a Dark Matter composed by supersymmetric particles
like neutralinos, we investigate the possibility that their annihilation in the
haloes of nearby galaxies could produce detectable fluxes of -photons.
Expected fluxes depend on several, poorly known quantities such as the density
profiles of Dark Matter haloes, the existence and prominence of central density
cusps and the presence of a population of sub-haloes. We find that, for all
reasonable choices of Dark Matter halo models, the intensity of the
-ray flux from some of the nearest extragalactic objects, like M31, is
comparable or higher than the diffuse Galactic foreground. We show that next
generation ground-based experiments could have the sensitivity to reveal such
fluxes which could help us unveiling the nature of Dark Matter particles.Comment: 11 pages, 10 figures. Accepted for publication in Phys. Rev. D.;
added a new paragraph on the detectability of Galactic sub-halos in our
Galaxy; added a discussion on their model dependence. The relation of our
results with the "CDM crisis" issue has also been adde
Magnetization dynamics with a spin-transfer torque
The magnetization reversal and dynamics of a spin valve pillar, whose lateral
size is 6464 nm, are studied by using micromagnetic simulation in
the presence of spin transfer torque. Spin torques display both characteristics
of magnetic damping (or anti-damping) and of an effective magnetic field. For a
steady-state current, both M-I and M-H hysteresis loops show unique features,
including multiple jumps, unusual plateaus and precessional states. These
states originate from the competition between the energy dissipation due to
Gilbert damping and the energy accumulation due to the spin torque supplied by
the spin current. The magnetic energy oscillates as a function of time even for
a steady-state current. For a pulsed current, the minimum width and amplitude
of the spin torque for achieving current-driven magnetization reversal are
quantitatively determined. The spin torque also shows very interesting thermal
activation that is fundamentally different from an ordinary damping effect.Comment: 15 figure
Muon anomalous magnetic moment, lepton flavor violation, and flavor changing neutral current processes in SUSY GUT with right-handed neutrino
Motivated by the large mixing angle solutions for the atmospheric and solar
neutrino anomalies, flavor changing neutral current processes and lepton flavor
violating processes as well as the muon anomalous magnetic moment are analyzed
in the framework of SU(5) SUSY GUT with right-handed neutrino. In order to
explain realistic mass relations for quarks and leptons, we take into account
effects of higher dimensional operators above the GUT scale. It is shown that
the supersymmetric (SUSY) contributions to the CP violation parameter in
mixing, , the branching ratio,
and the muon anomalous magnetic moment become large in a wide range of
parameter space. We also investigate correlations among these quantities.
Within the current experimental bound of , large
SUSY contributions are possible either in the muon anomalous magnetic moment or
in . In the former case, the favorable value of the recent muon
anomalous magnetic moment measurement at the BNL E821 experiment can be
accommodated. In the latter case, the allowed region of the Kobayashi-Maskawa
phase can be different from the prediction within the Standard Model (SM) and
therefore the measurements of the CP asymmetry of mode and
could discriminate this case from the SM. We also show that
the branching ratio can be close to the current
experimental upperbound and the mixing induced CP asymmetry of the radiative B
decay can be enhanced in the case where the neutrino parameters correspond to
the Mikheyev-Smirnov-Wolfenstein small mixing angle solution.Comment: 70 pages, 14 figure
Wetting films on chemically heterogeneous substrates
Based on a microscopic density functional theory we investigate the
morphology of thin liquidlike wetting films adsorbed on substrates endowed with
well-defined chemical heterogeneities. As paradigmatic cases we focus on a
single chemical step and on a single stripe. In view of applications in
microfluidics the accuracy of guiding liquids by chemical microchannels is
discussed. Finally we give a general prescription of how to investigate
theoretically the wetting properties of substrates with arbitrary chemical
structures.Comment: 56 pages, RevTeX, 20 Figure
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