Objectives
The aim of the study was to characterize contemporary patterns and correlates of testosterone therapy (TTh) use and discontinuation by HIV serostatus among men in the Multicenter AIDS ...Cohort Study (MACS).
Methods
Self‐reported testosterone use data were collected semiannually from 2400 (1286 HIV‐infected and 1114 HIV‐uninfected) men who have sex with men. Multivariable Poisson regression was used to estimate prevalence ratios for TTh use and predictors of TTh discontinuation (2012–2015).
Results
Use was higher among HIV‐infected compared with HIV‐uninfected men in all age strata, with an age‐adjusted prevalence of 17% vs. 5%, respectively (adjusted prevalence ratio 3.7; P < 0.001). Correlates of use in the multivariable model were similar by HIV serostatus: white race, the Los Angeles (LA) site, more than one recent sexual partner, non‐smoking status, and higher American Heart Association/American College of Cardiology (AHA/ACC) cardiovascular disease (CVD) risk score category (approximately 70% of testosterone users were in the high‐risk category). Compared with HIV‐uninfected men, HIV‐infected men more frequently reported building muscle mass as a motivation for testosterone use. The TTh discontinuation rate was 20.9/100 person‐years 95% confidence interval (CI) 17.3, 25.0/100 person‐years. Relative to HIV‐uninfected men, HIV‐infected men were half as likely to discontinue (adjusted incidence rate ratio 0.4; P < 0.001). Discontinuation was 40% higher in the period after the US Food and Drug Administration (FDA) safety communication for testosterone in 2014, independent of co‐factors (P = 0.06).
Conclusions
Given the high prevalence of both TTh use and CVD risk among HIV‐infected men, the benefits and risks of TTh should be examined in future studies of aging HIV‐infected men and monitored routinely in clinical practice.
We have used Soxhlet solvent purification to fractionate a broad molecular weight distribution of the polycarbazole polymer PCDTBT into three lower polydispersity molecular weight fractions. Organic ...photovoltaic devices were made using a blend of the fullerene acceptor PC₇₁BM with the molecular weight fractions. An average power conversion efficiency of 5.89% (peak efficiency of 6.15%) was measured for PCDTBT blend devices with a number average molecular weight of Mn = 25.5 kDa. There was significant variation between the molecular weight fractions with low (Mn = 15.0 kDa) and high (Mn = 34.9 kDa) fractions producing devices with average efficiencies of 5.02% and 3.70% respectively. Neutron reflectivity measurements on these polymer:PC₇₁BM blend layers showed that larger molecular weights leads to an increase in the polymer enrichment layer thickness at the anode interface, this improves efficiency up to a limiting point where the polymer solubility causes a reduction of the PCDTBT concentration in the active layer.
Adipose tissue (AT) density measurement may provide information about AT quality among people living with HIV. We assessed AT density and evaluated relationships between AT density and ...immunometabolic biomarker concentrations in men with HIV.
Cross-sectional analysis of men enrolled in the Multicenter AIDS Cohort Study.
Abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density (Hounsfield units, HU; less negative = more dense) were quantified from computed tomography (CT) scans. Multivariate linear regression models described relationships between abdominal AT density and circulating biomarker concentrations.
HIV+ men had denser SAT (-95 vs -98 HU HIV-, P < 0.001), whereas VAT density was equivalent by HIV serostatus men (382 HIV-, 462 HIV+). Historical thymidine analog nucleoside reverse transcriptase inhibitor (tNRTI) use was associated with denser SAT but not VAT. In adjusted models, a 1 s.d. greater SAT or VAT density was associated with higher levels of adiponectin, leptin, HOMA-IR and triglyceride:HDL cholesterol ratio and lower hs-CRP concentrations in HIV- men. Conversely, in HIV+ men, each s.d. greater SAT density was not associated with metabolic parameter improvements and was significantly (P < 0.05) associated with higher systemic inflammation. Trends toward higher inflammatory biomarker concentrations per 1 s.d. greater VAT density were also observed among HIV+ men.
Among men living with HIV, greater SAT density was associated with greater systemic inflammation independent of SAT area. AT density measurement provides additional insight into AT density beyond measurement of AT quantity alone, and may have implications for metabolic disease risk.
Objectives
Testosterone usage (T‐use) may alter risk factors for sudden cardiac death in men living with HIV (MLWH). Electrocardiographic QT interval prolongation, which could potentiate ventricular ...arrhythmias, has previously been associated with HIV infection and, separately, with low testosterone levels. We investigated whether T‐use shortens the QT interval duration in MLWH and HIV‐uninfected men.
Methods
We utilized data from the Multicenter AIDS Cohort Study, a prospective, longitudinal study of HIV infection among men who have sex with men. Multivariable linear regression analyses were used to evaluate associations between T‐use and corrected QT interval (QTc) duration.
Results
Testosterone usage was more common in MLWH compared with HIV‐uninfected men (19% vs. 9%). In a multivariable regression analysis, T‐use was associated with a 5.7 ms shorter QT interval 95% confidence interval (CI): −9.5 to −1.9; P = 0.003). Furthermore, stronger associations were observed for prolonged duration of T‐use and recent timing of T‐use.
Conclusions
This study is the first known analysis of T‐use and QTc interval in MLWH. Overall, our data demonstrate that recent T‐use is associated with a shorter QTc interval. Increased T‐use duration above a threshold of ≥ 50% of visits in the preceding 5 years was associated with a shorter QTc interval while lesser T‐use duration was not.
Recognizing high thermoelectric performance in semiconducting materials is a challenging task. This is because the Seebeck coefficient and electrical conductivity which constitute the thermoelectric ...power factor are unfavourably coupled. This means decoupling the transport properties of thermoelectric materials to enhance the power factor without compromising the thermal conductivity is essential. Herein we report that the substitution of erbium (Er) within bismuth selenide (Bi2Se3) results in a simultaneous enhancement in Seebeck coefficient and electrical conductivity via effective mass and Fermi energy optimization. The Er-Substitution in Bi2Se3 does not only promote a simultaneous increase in Seebeck coefficient and electrical conductivity but also decreases the thermal conductivity through an enhancement in phonon scattering.
Consequently, the optimum composition is found for the Bi1·85Er0·15Se3 sample instigating that, minimal substitution amount is required to optimize the thermoelectric performance. Our numerical calculation also shows that Er substitution alters the Fermi energy of the Bi2Se3 TE materials, thereby enhancing the effective mass. Through Raman and XPS characterization, we also elucidate that Er substitution does not change the chemical structure and chemical bonding of the pristine material appreciably. It thus leads to improvement in the Seebeck coefficient and electrical conductivity via effective mass optimization. This unique work presents a facile, scalable, cost-effective, and controllable synthesis of nanostructured Bi2Se3 toward realizing high-performance thermoelectric devices.
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•A facile synthesis of high purity erbium substituted Bi2Se3 thermoelectric material.•This study elucidates a mechanism of simultaneous enhancement in Seebeck coefficient and electrical conductivity through isovalent substitution.•Numerical discussion of the effect of the erbium substitution on the Fermi energy as evidence of the Seebeck coefficient and electrical conductivity decoupling is shown.•Systematic analysis of the structural, morphology and thermoelectric properties of the Er substituted Bi2Se3 is related.
Background. Highly active antiretroviral therapy (HAART), in addition to traditional vascular risk factors, may affect coronary heart disease (CHD) risk in individuals with human immunodeficiency ...virus (HIV) infection. Methods. Among HIV-infected (931 men and 1455 women) and HIV-uninfected (1099 men and 576 women) adults, the predicted risk of CHD was estimated on the basis of age, sex, lipid and blood pressure levels, the presence of diabetes, and smoking status. Results. Among HIV-infected men, 2% had moderate predicted risk of CHD (10-year CHD risk, 15%–25%), and 17% had high predicted risk (10-year CHD risk of ⩾25% or diabetes). Among HIV-infected women, 2% had moderate predicted CHD risk, and 12% had high predicted CHD risk. Compared with users of protease inhibitor–based HAART, the adjusted odds ratio (OR) for moderate-to-high risk of CHD was significantly lower among HAART-naive individuals (OR, 0.57; 95% confidence interval CI, 0.36–0.89). Users of HAART that was not protease inhibitor based (OR, 0.74; 95% CI, 0.53–1.01) and former HAART users (OR, 0.68; 95% CI, 0.46–1.03) were also less likely than users of protease inhibitor–based HAART to have moderate-to-high CHD risk, although 95% CIs overlapped the null. Low income was associated with increased likelihood of moderate-to-high CHD risk (for annual income <$10,000 vs. >$40,000: OR, 2.32; 95% CI, 1.51–3.56 ). Elevated body mass index (calculated as weight in kilograms divided by the square of height in meters) predicted increased likelihood of moderate-to-high CHD risk (for BMI of 18.5–24.9 vs. BMI of 25–30: OR, 1.41 95% CI, 1.03–1.93; for BMI of 18.5–24.9 vs. BMI ⩾30: OR, 1.79 95% CI, 1.25–2.56). Conclusions. Among HIV-infected adults, in addition to antiretroviral drug exposures, being overweight and having a low income level were associated with increased predicted CHD risk. This suggests a need to target HIV-infected men and women with these characteristics for vascular risk factor screening.
The relation between viremia and clinical outcome in individuals infected with human immunodeficiency virus-type 1 (HIV-1) has important implications for therapeutic research and clinical care. HIV-1 ...RNA in plasma was quantified with a branched-DNA signal amplification assay as a measure of viral load in a cohort of 180 seropositive men studied for more than 10 years. The risk of acquired immunodeficiency syndrome (AIDS) and death in study subjects, including those with normal numbers of CD4$^+$ T cells, was directly related to plasma viral load at study entry. Plasma viral load was a better predictor of progression to AIDS and death than was the number of CD4$^+$ T cells.
We report the fabrication of high performance organic solar cells by spray‐coating the photoactive layer in air. The photovoltaic blends consist of a blend of carbazole and benzothiadiazole based ...donor–acceptor copolymers and the fullerene derivative PC70BM. Here, we formulate a number of photovoltaic inks using a range of solvent systems that we show can all be deposited by spray casting. We use a range of techniques to characterize the structure of such films, and show that spray‐cast films have comparable surface roughness to spin‐cast films and that vertical stratification that occurs during film drying reduces the concentration of PCBM towards the underlying PEDOT:PSS interface. We also show that the active layer thickness and the drying kinetics can be tuned through control of the substrate temperature. High power conversion efficiencies of 4.3%, 4.5% and 4.6% were obtained for solar cells made from a blend of PC70BM with the carbazole‐based co‐polymers PCDTBT, P2 and P1. By applying a low temperature anneal after the deposition of the cathode, the efficiency of spray‐cast solar‐cells based on a P2:PC70BM blend is increased to 5.0%. Spray coating holds significant promise as a technique capable of fabricating large‐area, high performance organic solar cells in air.
High performance organic solar cells from the blend of donor–acceptor copolymers and PC70BM were made by spray‐coating the photoactive layer in air. A high power conversion efficiency of 5% was achieved after device optimization. Neutron scattering measurements show that vertical stratification occurs during the film drying process, and the concentration of PCBM reduces towards the underlying PEDOT:PSS interface.
The organozinc fluorocarboxylates RZnO2CRf and RZnO2CRf·TMEDA, along with Zn(O2CRf)2·TMEDA (R = Me, Et; Rf = C2F5, C3F7) have been synthesized. The structures of EtZnO2C2F5 (5), EtZnO2C3F7 (7), ...EtZnO2C2F5·TMEDA (11), Zn(O2C2F5)2·TMEDA (13), along with products from the adventitious reaction with either O2 or H2O, Zn10Me4(OMe)4(O2CC2F5)12 (2), Zn9Et2(O2CC2F5)12(O)2 (6), Zn8Et4(OEt)4(O2CC3F7)6(O) (8), Zn(O2CC3F7)2·TMEDA2·H2O (15) have been determined. Thin films of oriented ZnO have been deposited on glass substrates by low-pressure chemical vapor deposition (LPCVD) using 3 and 10 as precursors, though no fluorine incorporation in the films was noted. LPCVD using 13 as precursor also yielded fluorine-free ZnO, but lacking the oriented growth observed using 3, 10. However, 5, which exhibits short intermolecular Zn···F contacts in the solid state, thermally decomposes to bulk ZnF2.
A highly invasive form of non-typhoidal Salmonella (iNTS) disease has recently been documented in many countries in sub-Saharan Africa. The most common Salmonella enterica serovar causing this ...disease is Typhimurium (Salmonella Typhimurium). We applied whole-genome sequence-based phylogenetic methods to define the population structure of sub-Saharan African invasive Salmonella Typhimurium isolates and compared these to global Salmonella Typhimurium populations. Notably, the vast majority of sub-Saharan invasive Salmonella Typhimurium isolates fell within two closely related, highly clustered phylogenetic lineages that we estimate emerged independently ∼52 and ∼35 years ago in close temporal association with the current HIV pandemic. Clonal replacement of isolates from lineage I by those from lineage II was potentially influenced by the use of chloramphenicol for the treatment of iNTS disease. Our analysis suggests that iNTS disease is in part an epidemic in sub-Saharan Africa caused by highly related Salmonella Typhimurium lineages that may have occupied new niches associated with a compromised human population and antibiotic treatment.
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