On-Orbit Performance of Pd/4H-SiC Schottky UV Detectors in a Low-Earth Orbit

The monitoring of solar ultraviolet radiation from a space platform is now considered essential for a wide range of fieldsincluding solar physics, atmospheric science and astrobiology. 4H-Silicon Carbide (4H-SiC) is a superior alternative toconventional materials like silicon for the fabrication of UV detectors for adverse space conditions due to its inherentradiation hardness and visible-blind nature. This paper describes the space qualification and deployment of indigenouslydeveloped Pd/4H-SiC Schottky UV detectors in a low-earth orbit (LEO) and their on-board performance. Two SiC UVdetectors were flown as a rad-hard sun detection sensor in the nanosatellite INS-2TD. The sensor has carried out solar UVflux observations continuously since its launch in February 2022 and the data gathered during the first seven months offlight is discussed in this paper

Level of agreement between frequently used cardiovascular risk calculators in people living with HIV

Objectives The aim of the study was to describe agreement between the QRISK2, Framingham and Data Collection on Adverse Events of Anti‐HIV Drugs (D:A:D) cardiovascular disease (CVD) risk calculators in a large UK study of people living with HIV (PLWH). Methods PLWH enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study without a prior CVD event were included in this study. QRISK2, Framingham CVD and the full and reduced D:A:D CVD scores were calculated; participants were stratified into ‘low’ ( 20%) categories for each. Agreement between scores was assessed using weighted kappas and Bland–Altman plots. Results The 730 included participants were predominantly male (636; 87.1%) and of white ethnicity (645; 88.5%), with a median age of 53 [interquartile range (IQR) 49–59] years. The median calculated 10‐year CVD risk was 11.9% (IQR 6.8–18.4%), 8.9% (IQR 4.6–15.0%), 8.5% (IQR 4.8–14.6%) and 6.9% (IQR 4.1–11.1%) when using the Framingham, QRISK2, and full and reduced D:A:D scores, respectively. Agreement between the different scores was generally moderate, with the highest level of agreement being between the Framingham and QRISK2 scores (weighted kappa = 0.65) but with most other kappa coefficients in the 0.50–0.60 range. Conclusions Estimates of predicted 10‐year CVD risk obtained with commonly used CVD risk prediction tools demonstrate, in general, only moderate agreement among PLWH in the UK. While further validation with clinical endpoints is required, our findings suggest that care should be taken when interpreting any score alone

Depression, lifestyle factors and cognitive function in people living with HIV and comparable HIV-negative controls

We investigated whether differences in cognitive performance between people living with HIV (PLWH) and comparable HIV-negative people were mediated or moderated by depressive symptoms and lifestyle factors. METHODS: A cross-sectional study of 637 'older' PLWH aged ≥ 50 years, 340 'younger' PLWH aged < 50 years and 276 demographically matched HIV-negative controls aged ≥ 50 years enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study was performed. Cognitive function was assessed using a computerized battery (CogState). Scores were standardized into Z-scores [mean = 0; standard deviation (SD) = 1] and averaged to obtain a global Z-score. Depressive symptoms were evaluated via the Patient Health Questionnaire (PHQ-9). Differences between the three groups and the effects of depression, sociodemographic factors and lifestyle factors on cognitive performance were evaluated using median regression. All analyses accounted for age, gender, ethnicity and level of education. RESULTS: After adjustment for sociodemographic factors, older and younger PLWH had poorer overall cognitive scores than older HIV-negative controls (P < 0.001 and P = 0.006, respectively). Moderate or severe depressive symptoms were more prevalent in both older (27%; P < 0.001) and younger (21%; P < 0.001) PLWH compared with controls (8%). Depressive symptoms (P < 0.001) and use of hashish (P = 0.01) were associated with lower cognitive function; alcohol consumption (P = 0.02) was associated with better cognitive scores. After further adjustment for these factors, the difference between older PLWH and HIV-negative controls was no longer significant (P = 0.08), while that between younger PLWH and older HIV-negative controls remained significant (P = 0.01). CONCLUSIONS: Poorer cognitive performances in PLWH compared with HIV-negative individuals were, in part, mediated by the greater prevalence of depressive symptoms and recreational drug use reported by PLWH

On-Orbit Performance of Pd/4H-SiC Schottky UV Detectors in a Low-Earth Orbit

85-89The monitoring of solar ultraviolet radiation from a space platform is now considered essential for a wide range of fields including solar physics, atmospheric science and astrobiology. 4H-Silicon Carbide (4H-SiC) is a superior alternative to conventional materials like silicon for the fabrication of UV detectors for adverse space conditions due to its inherent radiation hardness and visible-blind nature. This paper describes the space qualification and deployment of indigenously developed Pd/4H-SiC Schottky UV detectors in a low-earth orbit (LEO) and their on-board performance. Two SiC UV detectors were flown as a rad-hard sun detection sensor in the nanosatellite INS-2TD. The sensor has carried out solar UV flux observations continuously since its launch in February 2022 and the data gathered during the first seven months of flight is discussed in this paper