98 research outputs found
Acute HIV infection and CD4/CD8 ratio normalization after antiretroviral therapy initiation
Background:We estimated the effect of initiating virologically suppressive antiretroviral therapy (ART) during acute HIV infection versus chronic HIV infection (AHI vs. CHI) on CD4/CD8 ratio normalization.Setting:A prospective clinical cohort study.Methods:We included patients initiating ART with AHI and CHI between 2000 and 2015 and compared time from ART initiation to the first normal CD4/CD8 ratio (defined as CD4/CD8 ≥1) using Kaplan-Meier curves and multivariable Cox proportional hazards models. Patient time was censored at virologic failure, lost to follow-up, or death. We also characterized CD4, CD8, and CD4/CD8 trajectories over the first 3 years of ART.Results:The 1198 patients were 27% female and 60% African American, with a median age of 37 years (interquartile range 28-47) at ART initiation. The 83 AHI patients were more likely male, younger, and of white race, than CHI patients. After 2 years of suppressive ART, 70% of AHI patients achieved a normal CD4/CD8 ratio, compared to 6%-38% of CHI patients, with greater likelihood of normalization at higher baseline CD4 counts. Time to normalization was shortest among AHI patients, followed by CHI patients with higher baseline CD4. The adjusted hazard ratio for time to normalization for AHI patients compared to CHI patients with baseline CD4 >350 was 4.33 (95% CI: 3.16 to 5.93). Higher baseline CD4/CD8 ratio was also associated with time to normalization (adjusted hazard ratio 1.54; 1.46, 1.63, per 0.1 increase in ratio).Conclusions:Initiating ART during AHI at higher baseline CD4 cell counts and CD4/CD8 ratios was associated with shorter time to CD4/CD8 ratio normalization
Quasifree eta photoproduction from nuclei and medium modifications of resonances
We investigate the sensitivity of the differential cross section, recoil
nucleon polarization and the photon asymmetry to changes in the elementary
amplitude, medium modifications of the resonance masses, as
well as nuclear target effects. All calculations are performed within a
relativistic plane wave impulse approximation formalism resulting in analytical
expressions for all observables. The spin observables are shown to be unique
tools to study subtle effects that are not accessible by only looking at the
unpolarized differential cross section.Comment: 27 pages, 8 figures, Revtex, To be published in Phys. Rev.
Immunogenicity of AGS-004 Dendritic Cell Therapy in Patients Treated during Acute HIV Infection
AGS-004 consists of matured autologous dendritic cells co-electroporated with in vitro transcribed RNA encoding autologous HIV antigens. In an open-label, single arm sub-study of AGS-004-003, AGS-004 was administered monthly to suppressed participants who started antiretroviral therapy (ART) during acute HIV infection. HIV-1 specific T cell responses were measured by multicolor flow cytometry after 3-4 doses. The frequency of resting CD4+ T-cell infection (RCI) was measured by quantitative viral outgrowth assay. Participants demonstrating increased immune response postvaccination were eligible for analytic treatment interruption (ATI). AGS-004 induced a positive immune response defined as ≥2-fold increase from baseline in the number of multifunctional HIV-1 specific CD28+/CD45RA- CD8+ effector/memory cytoxic T-lymphocytes (CTLs) in all six participants. All participants underwent ATI with rebound viremia at a median of 29 days. Immune correlates between time to viral rebound and the induction of effector CTLs were determined. Baseline RCI was low in most participants (0.043-0.767 IUPM). One participant had a >2-fold decrease (0.179-0.067 infectious units per million [IUPM]) in RCI at week 10. One participant with the lowest RCI had the longest ATI. AGS-004 dendritic cell administration increased multifunctional HIV-specific CD28+/CD45RA- CD8+ memory T cell responses in all participants, but did not permit sustained ART interruption. However, greater expansion of CD28-/CCR7-/CD45RA- CD8+ effector T cell responses correlated with a longer time to viral rebound. AGS-004 may be a useful tool to augment immune responses in the setting of latency reversal and eradication strategies
From thermal rectifiers to thermoelectric devices
We discuss thermal rectification and thermoelectric energy conversion from
the perspective of nonequilibrium statistical mechanics and dynamical systems
theory. After preliminary considerations on the dynamical foundations of the
phenomenological Fourier law in classical and quantum mechanics, we illustrate
ways to control the phononic heat flow and design thermal diodes. Finally, we
consider the coupled transport of heat and charge and discuss several general
mechanisms for optimizing the figure of merit of thermoelectric efficiency.Comment: 42 pages, 22 figures, review paper, to appear in the Springer Lecture
Notes in Physics volume "Thermal transport in low dimensions: from
statistical physics to nanoscale heat transfer" (S. Lepri ed.
Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution of Ices
This report arises from an ongoing program to monitor Neptune's largest moon
Triton spectroscopically in the 0.8 to 2.4 micron range using IRTF/SpeX. Our
objective is to search for changes on Triton's surface as witnessed by changes
in the infrared absorption bands of its surface ices N2, CH4, H2O, CO, and CO2.
We have recorded infrared spectra of Triton on 53 nights over the ten
apparitions from 2000 through 2009. The data generally confirm our previously
reported diurnal spectral variations of the ice absorption bands (Grundy &
Young 2004). Nitrogen ice shows a large amplitude variation, with much stronger
absorption on Triton's Neptune-facing hemisphere. We present evidence for
seasonal evolution of Triton's N2 ice: the 2.15 micron absorption band appears
to be diminishing, especially on the Neptune-facing hemisphere. Although it is
mostly dissolved in N2 ice, Triton's CH4 ice shows a very different
longitudinal variation from the N2 ice, challenging assumptions of how the two
ices behave. Unlike Triton's CH4 ice, the CO ice does exhibit longitudinal
variation very similar to the N2 ice, implying that CO and N2 condense and
sublimate together, maintaining a consistent mixing ratio. Absorptions by H2O
and CO2 ices show negligible variation as Triton rotates, implying very uniform
and/or high latitude spatial distributions for those two non-volatile ices.Comment: 22 pages, 13 figures, 5 tables, to appear in Icaru
Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy
During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly
Timing of colonoscopy after resection for colorectal cancer: Are we looking too soon?
BACKGROUND: Based on current National Comprehensive Cancer Network guidelines, colonoscopic surveillance after colorectal cancer resection should begin at 1 year
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