1,920 research outputs found
Sildenafil Citrate-Restored eNOS and PDE5 Regulation in Sickle Cell Mouse Penis Prevents Priapism Via Control of Oxidative/Nitrosative Stress
Sildenafil citrate revolutionized the practice of sexual medicine upon its federal regulatory agency approval approximately 15 years ago as the prototypical phosphodiesterase type 5 inhibitor indicated for the treatment of male erectile dysfunction. We now provide scientific support for its alternative use in the management of priapism, a clinical disorder of prolonged and uncontrolled penile erection. Sildenafil administered continuously to sickle cell mice, which show a priapism phenotype, reverses oxidative/nitrosative stress effects in the penis, mainly via reversion of uncoupled endothelial nitric oxide synthase to the functional coupled state of the enzyme, which in turn corrects aberrant signaling and function of the nitric oxide/cyclic GMP/protein kinase G/phosphodiesterase type 5 cascade. Priapism tendencies in these mice are reverted partially toward normal neurostimulated erection frequencies and durations after sildenafil treatment in association with normalized cyclic GMP concentration, protein kinase G activity and phosphodiesterase type 5 activity in the penis. Thus, sildenafil exerts pleiotropic effects in the penis that extend to diverse erection disorders. © 2013 Bivalacqua et al
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Application of semiconductor industry cleaning technologies for Genesis sample collectors
Genesis array collectors recovered after the sub-nominal landing have been exposed to particulate and molecular contamination. In this study, semiconductor industry based cleaning technologies are being evaluated for their efficacy in contaminant removal
Mott insulators in an optical lattice with high filling factors
We discuss the superfluid to Mott insulator transition of an atomic Bose gas
in an optical lattice with high filling factors. We show that also in this
multi-band situation, the long-wavelength physics is described by a single-band
Bose-Hubbard model. We determine the many-body renormalization of the tunneling
and interaction parameters in the effective Bose-Hubbard Hamiltonian, and
consider the resulting model at nonzero temperatures. We show that in
particular for a one or two-dimensional optical lattice, the Mott insulator
phase is more difficult to realize than anticipated previously.Comment: 5 pages, 3 figures, title changed, major restructuring, resubmitted
to PR
A low-voltage retarding-field Mott polarimeter for photocathode characterization
Nuclear physics experiments at Thomas Jefferson National Accelerator
Facility's CEBAF rely on high polarization electron beams. We describe a
recently commissioned system for prequalifying and studying photocathodes for
CEBAF with a load-locked, low-voltage polarized electron source coupled to a
compact retarding-field Mott polarimeter. The polarimeter uses simplified
electrode structures and operates from 5 to 30 kV. The effective Sherman
function for this device has been calibrated by comparison with the CEBAF 5 MeV
Mott polarimeter. For elastic scattering from a thick gold target at 20 keV,
the effective Sherman function is 0.201(5). Its maximum efficiency at 20 keV,
defined as the detected count rate divided by the incident particle current, is
5.4(2) x 10-4, yielding a figure-of-merit, or analyzing power squared times
efficiency, of 1.0(1) x 10-5. The operating parameters of this new polarimeter
design are compared to previously published data for other compact Mott
polarimeters of the retarding-field type.Comment: 9 figure
Alignment in Gamma-Hadron Families of Cosmic Rays
Alignment of main fluxes of energy in a target plane is found in families of
cosmic ray particles detected in deep lead X-ray chambers. The fraction of
events with alignment is unexpectedly large for families with high energy and
large number of hadrons. This can be considered as evidence for the existence
of coplanar scattering of secondary particles in interaction of particles with
superhigh energy, eV. Data analysis suggests that production of
most aligned groups occurs low above the chamber and is characterized by a
coplanar scattering and quasiscaling spectrum of secondaries in the
fragmentation region. The most elaborated hypothesis for explanation of
alignment is related to the quark-gluon string rupture. However, the problem of
theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University
preprint SU-ITP-94-2
Beyond Gross-Pitaevskii Mean Field Theory
A large number of effects related to the phenomenon of Bose-Einstein
Condensation (BEC) can be understood in terms of lowest order mean field
theory, whereby the entire system is assumed to be condensed, with thermal and
quantum fluctuations completely ignored. Such a treatment leads to the
Gross-Pitaevskii Equation (GPE) used extensively throughout this book. Although
this theory works remarkably well for a broad range of experimental parameters,
a more complete treatment is required for understanding various experiments,
including experiments with solitons and vortices. Such treatments should
include the dynamical coupling of the condensate to the thermal cloud, the
effect of dimensionality, the role of quantum fluctuations, and should also
describe the critical regime, including the process of condensate formation.
The aim of this Chapter is to give a brief but insightful overview of various
recent theories, which extend beyond the GPE. To keep the discussion brief,
only the main notions and conclusions will be presented. This Chapter
generalizes the presentation of Chapter 1, by explicitly maintaining
fluctuations around the condensate order parameter. While the theoretical
arguments outlined here are generic, the emphasis is on approaches suitable for
describing single weakly-interacting atomic Bose gases in harmonic traps.
Interesting effects arising when condensates are trapped in double-well
potentials and optical lattices, as well as the cases of spinor condensates,
and atomic-molecular coupling, along with the modified or alternative theories
needed to describe them, will not be covered here.Comment: Review Article (19 Pages) - To appear in 'Emergent Nonlinear
Phenomena in Bose-Einstein Condensates: Theory and Experiment', Edited by
P.G. Kevrekidis, D.J. Frantzeskakis and R. Carretero-Gonzalez (Springer
Verlag
Impact of process variables on the micromeritic and physicochemical properties of spray-dried microparticles, part II: physicochemical characterisation of spray-dried materials
YesObjectives In this work we investigated the residual organic solvent content and physicochemical properties of spray-dried chlorothiazide sodium (CTZNa) and potassium (CTZK) salts.
Methods The powders were characterised by thermal, X-ray diffraction, infrared and dynamic vapour sorption (DVS) analyses. Solvent levels were investigated by Karl–Fischer titration and gas chromatography.
Key findings Spray-drying from water, methanol (MeOH) and mixes of MeOH and butyl acetate (BA) resulted in amorphous microparticles. The glass transition temperatures of CTZNa and CTZK were ∼192 and ∼159°C, respectively. These materials retained their amorphous nature when stored at 25°C in dry conditions for at least 6 months with no chemical decomposition observed. DVS determined the critical relative humidity of recrystallisation of CTZNa and CTZK to be 57% RH and 58% RH, respectively. The inlet temperature dependant oxidation of MeOH to formaldehyde was observed; the formaldehyde was seen to deposit within the amorphous matrix of spray-dried product. Spray-drying in the open blowing mode coupled with secondary drying resulted in a three-fold reduction in residual BA (below pharmacopoeial permitted daily exposure limit) compared to spray-drying in the closed mode.
Conclusions Experiments showed that recirculation of recovered drying gas increases the risk of deposition of residual solvents in the spray-dried product.The Irish Research Council for Science and Engineering Technology (IRCSET), the Solid State Pharmaceutical Cluster (SSPC), supported by Science Foundation Ireland under grant number (07/SRC/B1158) and the Irish Drug Delivery Research Network, a Strategic Research Cluster grant (07/SRC/B1154) under the National Development Plan co-funded by EU Structural Funds and Science Foundation Ireland
Ambient particulate matter air pollution exposure and mortality in the NIH-AARP diet and health cohort
BACKGROUND: Outdoor fine particulate matter (≤ 2.5 μm; PM2.5) has been identified as a global health threat, but the number of large U.S. prospective cohort studies with individual participant data remains limited, especially at lower recent exposures. OBJECTIVES: We aimed to test the relationship between long-term exposure PM2.5 and death risk from all nonaccidental causes, cardiovascular (CVD), and respiratory diseases in 517,041 men and women enrolled in the National Institutes of Health-AARP cohort. METHODS: Individual participant data were linked with residence PM2.5 exposure estimates across the continental United States for a 2000–2009 follow-up period when matching census tract–level PM2.5 exposure data were available. Participants enrolled ranged from 50 to 71 years of age, residing in six U.S. states and two cities. Cox proportional hazard models yielded hazard ratio (HR) estimates per 10 μg/m3 of PM2.5 exposure. RESULTS: PM2.5 exposure was significantly associated with total mortality (HR = 1.03; 95% CI: 1.00, 1.05) and CVD mortality (HR = 1.10; 95% CI: 1.05, 1.15), but the association with respiratory mortality was not statistically significant (HR = 1.05; 95% CI: 0.98, 1.13). A significant association was found with respiratory mortality only among never smokers (HR = 1.27; 95% CI: 1.03, 1.56). Associations with 10-μg/m3 PM2.5 exposures in yearly participant residential annual mean, or in metropolitan area-wide mean, were consistent with baseline exposure model results. Associations with PM2.5 were similar when adjusted for ozone exposures. Analyses of California residents alone also yielded statistically significant PM2.5 mortality HRs for total and CVD mortality. CONCLUSIONS: Long-term exposure to PM2.5 air pollution was associated with an increased risk of total and CVD mortality, providing an independent test of the PM2.5–mortality relationship in a new large U.S. prospective cohort experiencing lower post-2000 PM2.5 exposure levels. CITATION: Thurston GD, Ahn J, Cromar KR, Shao Y, Reynolds HR, Jerrett M, Lim CC, Shanley R, Park Y, Hayes RB. 2016. Ambient particulate matter air pollution exposure and mortality in the NIH-AARP Diet and Health cohort. Environ Health Perspect 124:484–490; http://dx.doi.org/10.1289/ehp.150967
How do general practitioners experience providing care to refugees with mental health problems? A qualitative study from Denmark
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
The potential of human induced pluripotent stem cells for modelling diabetic wound healing in vitro
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