4,249 research outputs found
Optimizing ribavirin dose in HIV/hepatitis C (HCV) co-infected individuals treated for HCV
Hepatitis C (HCV) and HIV share common transmission pathways and the acquisition of both viruses are relatively common. Concurrent treatment for HCV with highly active anti-retroviral therapy (HAART) should be considered in HIV co-infected individuals to decrease the progression of liver damage. Adverse effects and less satisfactory treatment outcomes are often concerns when treating co-infected individuals. Although, direct acting antivirals (DAAs) may increase SVR, they may not be possible because of drug-drug interactions. he objective of this study is to investigate the difference in response rates of HCV treatment in HIV co-infected inmates with varying doses of ribavirin. Retrospective medical chart reviews of 52 HCV/HIV co-infected inmates who underwent HCV therapy between 2003 and 2010. All received standard doses of pegylated interferon alpha 2a or 2b and 800–1600 mg of ribavirin depending on weight. The recommended dosage for genotypes 2 and 3 is 800 mg/day. For other genotypes, if weight is<75 kg, the recommended ribavirin dose is 1000 mg/day or 1200 mg/day if>75 kg. Efficacy was defined as attaining sustained virological response (SVR) six months post treatment. Univariate analyses was performed using SPSS-18; Chi-square test with p-value<0.05 was defined significant. 52 co-infected (3 females & 49 males) were identified. Mean age was 40±7 years. Caucasians accounted for 84.6%; First Nations for 13.5% and Asians 1.9%. 36 were concurrently on HAART. The genotype distribution was: geno 1, 66.0%; geno 2, 7.5%; geno 3, 26.4%. SVR by ribavirin dosage ratio (actual dosage/recommended dosage):=1.0; 41.2% (14/34),>1.0; 58.8% (20/34). Doses greater than 1.5 times were associated with higher adverse events and lower SVR. Suboptimal doses of weight-based ribavirin may be contributing to a lower treatment response in HCV/HIV co-infectants. In our experience, the optimal dose of ribavirin is between 1 and 1.2 times the current recommended dose. We recommend that ribavirin dose be individualized in co-infected in order to enhance the likelihood of achieving SVR. Dual therapy is more practical in many of our population because of chaotic lifestyle. Therefore optimizing the ribavirin dose should be initially undertaken
Electrons on a sphere in disorder potential
We investigate, both analytically and numerically, the behavior of the
electron gas on a sphere in the presence of point-like impurities. We find a
criterion when the disorder can be regarded as small one and the main effect is
the broadening of rotational multiplets. In the latter regime the statistics of
one impurity-induced band is studied numerically. The energy level spacing
distribution function follows the law P(s) ~ s exp(-a s^b) with 1<b<2. The
number variance shows various possibilities, strongly dependent on the chosen
model of disorder.Comment: 11 pages, REVTEX, 9 eps figures; references added to Sec.
Development of the legitimacy threshold scale
A consensus in the literature supports the premise that legitimacy attainment facilitates favorable judgments from key stakeholders regarding the acceptability, appropriateness and worthiness of entrepreneurs and their efforts in emerging ventures. However, although legitimacy attainment is a milestone that emerging ventures strive to reach, as researchers we do not yet have a measure that examines whether a firm is operating pre- versus post-legitimacy. Accordingly, we develop the legitimacy threshold scale (LTS) that will facilitate the assessment of activities performed pre- and post-legitimacy in emerging ventures
Hybrid squeezing of solitonic resonant radiation in photonic crystal fibers
We report on the existence of a novel kind of squeezing in photonic crystal
fibers which is conceptually intermediate between the four-wave mixing induced
squeezing, in which all the participant waves are monochromatic waves, and the
self-phase modulation induced squeezing for a single pulse in a coherent state.
This hybrid squeezing occurs when an arbitrary short soliton emits
quasi-monochromatic resonant radiation near a zero group velocity dispersion
point of the fiber. Photons around the resonant frequency become strongly
correlated due to the presence of the classical soliton, and a reduction of the
quantum noise below the shot noise level is predicted.Comment: 5 pages, 2 figure
Transmission-dominated mid-infrared supermirrors with finesse exceeding 200 000
We fabricate and characterize substrate-transferred single-crystal mirror
coatings with 9.33 0.17 ppm of transmittance and 4.27 0.52 ppm of
excess optical loss, corresponding to a transmission-loss dominated reflectance
of 99.9986% at 4.45 m. For the first time, a cavity finesse > 200 000 is
achieved in the mid-infrared.Comment: Sept 21: Minor revisions to conform to 2-page length requirement
including abbr. refs.; Figure font sizes increase
Estimating vehicle carbon dioxide emissions from Boulder, Colorado, using horizontal path-integrated column measurements
We performed 7.5 weeks of path-integrated concentration
measurements of CO2, CH4, H2O, and HDO over the city of Boulder, Colorado. An open-path dual-comb spectrometer simultaneously
measured time-resolved data across a reference path, located near the
mountains to the west of the city, and across an over-city path that
intersected two-thirds of the city, including two major commuter arteries. By
comparing the measured concentrations over the two paths when the wind is
primarily out of the west, we observe daytime CO2 enhancements over
the city. Given the warm weather and the measurement footprint, the dominant
contribution to the CO2 enhancement is from city vehicle traffic. We
use a Gaussian plume model combined with reported city traffic patterns to
estimate city emissions of on-road CO2 as (6.2±2.2) × 105 metric tons (t) CO2 yr−1
after correcting for non-traffic sources. Within the uncertainty, this value
agrees with the city's bottom-up greenhouse gas inventory for the on-road
vehicle sector of 4.5×105 t CO2 yr−1. Finally, we
discuss experimental modifications that could lead to improved estimates from
our path-integrated measurements.</p
Erratum: Quantitative atomic spectroscopy for primary thermometry [Phys. Rev. A 83, 033805 (2011)]
Original article was published with a typographical error in Eq. (4) on p. 6, in Physical Review A, 2011; 83(3):033805-1-033805-9.Gar-Wing Truong, Eric F. May, Thomas M. Stace, and André N. Luite
Kosterlitz-Thouless transition in three-state mixed Potts ferro-antiferromagnets
We study three-state Potts spins on a square lattice, in which all bonds are
ferromagnetic along one of the lattice directions, and antiferromagnetic along
the other. Numerical transfer-matrix are used, on infinite strips of width
sites, . Based on the analysis of the ratio of scaled mass
gaps (inverse correlation lengths) and scaled domain-wall free energies, we
provide strong evidence that a critical (Kosterlitz-Thouless) phase is present,
whose upper limit is, in our best estimate, . From analysis
of the (extremely anisotropic) nature of excitations below , we argue that
the critical phase extends all the way down to T=0. While domain walls parallel
to the ferromagnetic direction are soft for the whole extent of the critical
phase, those along the antiferromagnetic direction seem to undergo a softening
transition at a finite temperature. Assuming a bulk correlation length varying,
for , as , , we attempt finite-size scaling plots of our finite-width
correlation lengths. Our best results are for . We propose a
scenario in which such inconsistency is attributed to the extreme narrowness of
the critical region.Comment: 11 pages, 6 .eps figures, LaTeX with IoP macros, to be published in J
Phys
A global fit of and elastic scattering in ChPT with dispersion relations
We apply the one-loop results of the ChPT suplemented
with the inverse amplitude method to fit the available experimental data on
and scattering. With esentially only three parameters we
describe accurately data corresponding to six different channels, namely
and . In addition we
reproduce the first resonances of the and channel with the
right mass corresponding to the and the particles.Comment: 19 pages, 5 figures available on request, FT/UCM/10/9
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