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This study selected ZrB2–hBN ceramics as the matrix for low‐cost second‐generation SiC fibers, due to their low modulus and ability to be sintered at relatively low temperatures. The resulting composites, which contained up to 30 wt.% short‐chopped SiCf, were consolidated using reactive spark plasma sintering at 1550 and 1700°C under 50 MPa for 5 min. Without needing to prepare interfaces on the SiCf surfaces, fiber pullout, strengthening, and toughening during the fracture process were realized. By constructing the volatility phase diagram for the fiber, the microstructural changes that occurred on the fiber surfaces during sintering were successfully illustrated. Mechanical properties of ZrB2–hBN ceramics with 10 wt.% SiCf sintered at 1550°C still showed considerable improvements, including an elastic modulus of 187 GPa, a flexural strength of 337 ± 16 MPa, and a fracture toughness of 4.12 ± 0.25 MPa m1/2, increases of 12.6%, 61.2%, and 118%, respectively, compared to the counterparts without adding chopped fibers. Variations in these properties were linked to the matrix porosity and SiCf pullout behaviors, which were subsequently analyzed using the He–Hutchinson model. [ABSTRACT FROM AUTHOR]

Ceramics were susceptible to thermal shock failure. In this work, aluminum nitride‐based ceramics with excellent thermal shock resistance were developed. Thermal shock resistance was evaluated in the temperature range of 1200–1600°C by thermal cycling of 10, 20, 30, and 50 times. The phase composition, microstructure, and mechanical properties of the ceramics before and after the thermal shock were investigated. After 50 thermal cycles, the retention rates of the flexural strength and fracture toughness were 81.7% and 113.1%, respectively. The excellent thermal shock resistance was attributed to the combined effects of amorphous grain boundaries that passivate the propagation of microcracks and in‐situ precipitation of nanocrystalline particles during thermal cycles, both of which provide useful guidelines for developing ceramics with better thermal shock resistances. [ABSTRACT FROM AUTHOR]

Identifying the prevalence and risk factors of secondary human immunodeficiency virus (HIV) transmission from people living with HIV (PLWH) to other people is crucial for ending the HIV epidemic. However, the data among antiretroviral therapy (ART) patients is limited. This study aims to assess the prevalence and risk factors of secondary HIV transmission among PLWH receiving ART by longitudinal molecular networks in China. In this study, the prevalence of secondary HIV transmission was 10.8%. The R 0 was greater than 1 from 2017 to 2021 and peaked in 2019. PLWHs who were male sex, older age, engaged in condomless sex, experienced higher ART follow-up viral load, experienced ART medical omissions, infected with non-CRF01_AE subtype, and self-reported sexually transmitted infections (STIs) at HIV diagnosis increased the risk of secondary HIV transmission. However, those participants with higher education were less likely to be involved in secondary HIV transmission. The diagnostic age of the participants was nonlinearly associated with the risk of secondary HIV transmission, with a cutoff value of 43.13 years indicating a higher risk of secondary HIV transmission for patients diagnosed at or above this age. This study revealed substantial secondary HIV transmission and persistent HIV expansion among local PLWH, highlighting the necessity of enhancing viral load monitor, promoting adherence to ART, and promoting safe sex practices, particularly among older adults with HIV, to mitigate secondary HIV transmission.

Background: There is increasing focus on HIV-1 CRF55_01B in China. However, there is limited information regarding the dissemination of CRF55_01B across different regions and populations in Guangxi. This study was performed to elucidate the evolutionary history of the introduction and dissemination of CRF55_01B in Guangxi., Methods: Molecular network and phylogenetic analyses were used to investigate the transmission characteristics of CRF55_01B in China. The analyses particularly focused on the cross-provincial spatial and temporal transmission patterns between Guangdong Province and Guangxi, as well as the transmission dynamics among different regions and populations within Guangxi., Results: In total, 2226 partial pol sequences of CRF55_01B strains sampled from 2007 to 2022 were collected, including 1895 (85.09%) sequences from Guangdong, 199 (8.94%) sequences from Guangxi, and 172 (7.59%) sequences from other provinces of China. Most people living with HIV in Guangxi were infected with HIV-1 through heterosexuals (52.76%). Among these, 19.10% had a history of commercial heterosexual contact (CHC) and 15.58% had a history of non-marital non-commercial heterosexual contact (NMNCHC). Overall, 1418 sequences were identified in the molecular network. Notably, the sequences from Guangdong Province were most closely linked to those from Guangxi. Phylogenetic analysis showed that CRF55_01B was first introduced from Shenzhen City to Nanning City around 2007. Subsequently, CRF55_01B established local transmission within Guangxi, with Nanning City serving as the transmission center from 2008 to 2017. After 2017, the CRF55_01B strain spread to other regions of Guangxi. Men who have sex with men (MSM) and men with a history of CHC have played a significant role in the transmission of CRF55_01B among different populations in Guangxi., Conclusions: This study provides evidence on the transmission trajectory of CRF55_01B among different regions and populations in Guangxi. Given the bridging role of men with a history of CHC in the dissemination of CRF55_01B from MSM to the general population, it is imperative to enhance surveillance among key populations to mitigate the secondary transmission of HIV-1., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Luo, Zhang, Liang, Yu, Cen, Zhong, Qin, Yang, Jiang, Liao, Li, Zhang, Li, Lin, Ye, Liang and Liang.)