1,555 research outputs found
Comparison of Generic and Proprietary Sodium Stibogluconate for the Treatment of Visceral Leishmaniasis in Kenya.
OBJECTIVE: To compare the use of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis (kala-azar). METHODS: A total of 102 patients with confirmed kala-azar were treated in a mission hospital in West Pokot region, Kenya, with sodium stibogluconate (20 mg/kg/day for 30 days)--either as Pentostam (PSM) or generic sodium stibogluconate (SSG); 51 patients were allocated alternately to each treatment group. FINDINGS: There were no significant differences in baseline demographic characteristics or disease severity, or in events during treatment. There were 3 deaths in the PSM group and 1 in the SSG group; 2 patients defaulted in each group. Only 1 out of 80 test-of-cure splenic aspirates was positive for Leishmania spp.; this patient was in the SSG group. Follow-up after > or = 6 months showed that 6 out of 58 patients had relapsed, 5 in the SSG group and 1 in the PSM group. No outcome variable was significantly different between the two groups. CONCLUSION: The availability of cheaper generic sodium stibogluconate, subject to rigid quality controls, now makes it possible for the health authorities in kala-azar endemic areas to provide treatment to many more patients in Africa
Non-adiabatic effects in the phonon dispersion of Mg 1--x Al x B 2
Superconducting MgB shows an E zone center phonon, as measured
by Raman spectroscopy, that is very broad in energy and temperature dependent.
The Raman shift and lifetime show large differences with the values elsewhere
in the Brillouin Zone measured by Inelastic X-ray Scattering (IXS), where its
dispersion can be accounted for by standard harmonic phonon theory, adding only
a moderate electron-phonon coupling. Here we show that the effects rapidly
disappear when electron-phonon coupling is switched off by Al substitution on
the Mg sites. Moreover, using IXS with very high wave-vector resolution in
MgB, we can follow the dispersion connecting the Raman and the IXS signal,
in agreement with a theory using only electron-phonon coupling but without
strong anharmonic terms. The observation is important in order to understand
the effects of electron-phonon coupling on zone center phonons modes in
MgB, but also in all metals characterized by a small Fermi velocity in a
particular direction, typical for layered compounds
Electron-phonon coupling and superconductivity in -MoB as a function of pressure
We have studied the lattice dynamics, electron-phonon coupling, and
superconducting properties of -MoB, as a function of applied
pressure, within the framework of density functional perturbation theory using
a mixed-basis pseudopotential method. We found that phonon modes located along
the AH, HL, and LA high-symmetry paths exhibit large phonon linewidths
and contribute significantly to the electron-phonon coupling constant. Although
linewidths are particularly large for the highest-frequency optical phonon
modes (dominated by B vibrations), their contribution to the electron-phonon
coupling constant is marginal. The latter is largely controlled by the acoustic
low-frequency modes of predominantly Mo character. It was observed that at a
pressure of ~GPa, where -MoB forms, the phonon-mediated pairing
falls into the strong-coupling regime, and the estimate for the superconducting
critical temperature agrees well with experimental observations. When
further increasing the applied pressure, a reduction of is predicted,
which correlates with a hardening of the acoustic low-frequency phonon modes
and a decrease of the electron-phonon coupling parameter.Comment: Updated and accepted for publication versio
Training telescope operators and support astronomers at Paranal
The operations model of the Paranal Observatory relies on the work of
efficient staff to carry out all the daytime and nighttime tasks. This is
highly dependent on adequate training. The Paranal Science Operations
department (PSO) has a training group that devises a well-defined and
continuously evolving training plan for new staff, in addition to broadening
and reinforcing courses for the whole department. This paper presents the
training activities for and by PSO, including recent astronomical and quality
control training for operators, as well as adaptive optics and interferometry
training of all staff. We also present some future plans.Comment: Paper 9910-123 presented at SPIE 201
Assessing the causal effect of binary interventions from observational panel data with few treated units
Researchers are often challenged with assessing the impact of an intervention
on an outcome of interest in situations where the intervention is
non-randomised, the intervention is only applied to one or few units, the
intervention is binary, and outcome measurements are available at multiple time
points. In this paper, we review existing methods for causal inference in these
situations. We detail the assumptions underlying each method, emphasize
connections between the different approaches and provide guidelines regarding
their practical implementation. Several open problems are identified thus
highlighting the need for future research
A first-principles study of superconductivity on RbH by doping without applied pressure
The structural, electronic, lattice dynamics, electron-phonon coupling, and
superconducting properties of the alkali-metal hydride RbH, metalized through
electron-doping by the construction of the solid-solution RbSrH,
are systematically analyzed as a function of Sr-content within the framework of
density functional perturbation and Migdal-Eliashberg theories, taking into
account the effect of zero-point energy contribution by the quasi-harmonic
approximation. For the entire studied range of Sr-content, steady increments of
the electron-phonon coupling constant and the superconducting critical
temperature are found with progressive alkaline-earth metal content through
electron-doping, reaching the values of and ~K
with =0.1(0). The steady rise of such quantities as a function of
Sr-content is consequence of the metallization of the hydride as an increase of
density of states at the Fermi level is observed, as well as the softening of
the phonon spectrum, mainly coming from H-optical modes. Our results indicate
that electron-doping on metal-hydrides is an encouraging alternative to look
for superconductivity without applied pressure.Comment: 8 pages, 6 figure
- …