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Taguchi-grey relational analysis (GRA) coupled with principal component analysis (PCA) has been employed to optimize the multi-response wear characteristics of the trimethoxymethylsilane treated flax fibre reinforced epoxy (F-E) composites. Dry sliding wear test has been performed as per ASTM G99 based on the experimental schedule of Taguchi's orthogonal arrays (L27). Wear responses selected for the current investigation are specific wear rate (SWR), coefficient of friction (COF) and shore D hardness. Analysis of variance (ANOVA) of GRG clearly reveals that sliding velocity is most significant factor affecting the wear performance of the F-E composites followed by fibre content and applied load. Fieldemission scanning electron microscopy reveals that F-E composite endure thermal softening and cracks around its interfacial bonding region. [ABSTRACT FROM AUTHOR]

Background: HIV infection causes immune dysregulation affecting T-cell and monocyte function, which may alter coronavirus disease 2019 (COVID-19) pathophysiology., Objectives: We investigated the associations among clinical phenotypes, laboratory biomarkers, and hospitalisation outcomes in a cohort of people hospitalised with COVID-19 in a high HIV prevalence area., Method: We conducted a prospective observational cohort study in Tshwane, South Africa. Respiratory disease severity was quantified using the respiratory oxygenation score. Analysed biomarkers included inflammatory and coagulation biomarkers, CD4 T-cell counts, and HIV-1 viral loads (HIVVL)., Results: The analysis included 558 patients, of whom 21.7% died during admission. The mean age was 54 years. A total of 82 participants were HIV-positive. People living with HIV (PLWH) were younger (mean age 46 years) than HIV-negative people; most were on antiretroviral treatment with a suppressed HIVVL (72%) and the median CD4 count was 159 (interquartile range: 66-397) cells/µL. After adjusting for age, HIV was not associated with increased risk of mortality during hospitalisation (age-adjusted hazard ratio = 1.1, 95% confidence interval: 0.6-2.0). Inflammatory biomarker levels were similar in PLWH and HIV-negative patients. Detectable HIVVL was associated with less severe respiratory disease. In PLWH, mortality was associated with higher levels of inflammatory biomarkers. Opportunistic infections, and other risk factors for severe COVID-19, were common in PLWH who died., Conclusion: PLWH were not at increased risk of mortality and those with detectable HIVVL had less severe respiratory disease than those with suppressed HIVVL., What This Study Adds: This study advances our understanding of severe COVID-19 in PLWH., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article., (© 2023. The Authors.)