Telomeres are DNA-protein complexes at the ends of eukaryotic chromosomes that play an important role in maintaining the integrity of the genome. In proliferative stem cells and cancer cells, telomere length is maintained by telomerase, and telomere structure and functions are regulated by telomere-associated proteins. We find that telomerase levels are high in embryonic cortical neural progenitor cells (NPCs) and low in newly generated neurons (NGNs) and mature neurons (MNs). In contrast, telomere repeat-binding factor 2 (TRF2) expression is undetectable in early brain development in vivo and in cultured NPCs and is expressed at progressively higher levels as NPCs cease proliferation and differentiate into postmitotic neurons. The telomere-disrupting agent telomestatin induces a DNA damage response and apoptosis in NGNs (which have low levels of TRF2 and telomerase), whereas NPCs (which have high levels of telomerase) and MNs (which have high levels of TRF2) are resistant to telomere damage. Overexpression of TRF2 in NGNs protects them against death induced by telomestatin and other DNA-damaging agents. Knockdown of TRF2 expression in MNs and knock-out of telomerase reverse transcriptase in NPCs increased their sensitivity to telomere-and DNA-damaging agents but did not affect the vulnerability of NGNs. These findings suggest that TRF2 and telomerase function as distinct telomere protection mechanisms during the processes of neurogenesis and neuronal maturation and that hypersensitivity of NGNs to telomere damage results from relative deficiencies of both telomerase and TRF2.

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Epoxy motifs are versatile building blocks for use in pharmaceuticals, food additives and agrochemicals. Here, we present a highly efficient electrochemical bromide-mediated olefin epoxidation process using H2O for a broad scope of substrates.

BACKGROUND Risky sexual behaviour (RSB) drives the HIV and sexually transmitted infection (STI) epidemic among college students. Yet research on RSB remains limited among students with sexual experience in China. OBJECTIVE This study aims to determine the prevalence of RSBs and its correlates among students with sexual experience in Guangxi. METHODS A cross-sectional study was conducted among students with sexual experience from 14 colleges in Nanning City of Guangxi Province in 2021, using a convenience sampling method. Participants' sociodemographic characteristics, HIV/sexual health-related knowledge, sexual attitudes, sex education, behavioural characteristics, and HIV prevention service use were collected using a self-designed anonymous online questionnaire. A chi-square test was used to compare differences in the distribution of sexual characteristics and demographic information. Univariate analysis and logistic regression models were used to analyse the correlates of RSBs. RESULTS A total of 13,201 students completed the survey. It was found that 5.5% and 9.5% of participants reported having engaged in casual and commercial sex in the past year, respectively. Sexually experienced college students who were being single (adjusted odds ratio [aOR] 1.99, 95% CI 1.53–2.59), having higher number of sexual partners (aOR 2.08, 95% CI 1.34–3.23), having ever sought sexual partners online (aOR 8.29, 95% CI 5.94–11.57), having sex in the past year (aOR 8.40, 95%CI 5.65–12.50), having used psychotropic drug (aOR 5.91, 95% CI 3.28–10.63), and receiving AIDS education in the past year (aOR 2.79, 95% CI 1.81–4.29) were more likely to engage in casual sex. Being female sex (aOR 0.49, 95% CI 0.35–0.69), having sexual health-related knowledge (aOR 1.65, 95% CI 1.27–2.14), having ever sought sexual partners online (aOR 4.47, 95% CI 2.77–7.20; aOR 5.81,95% CI 4.2–8.04), and psychotropic drug use (aOR 17.72, 95% CI 11.37–27.62) were more likely to have commercial sexual behaviour. CONCLUSIONS The prevalence of casual sexual behaviour and commercial sexual behaviour was relatively high in sexually experienced students. This study highlights the need for a more targeted and effective inventions for college students, such as earlier and consecutive sex education, psychotropic drug use education, and HIV/STI prevention services, which should be implemented on campus to mitigate the RSBs that may contribute to HIV and STIs in this population.

The purpose of this study was to describe the mortality patterns in the southern provinces of China, and to provide epidemiologic data on sex and age differences of death outcomes. Reliable mortality and population data from January 2004 to December 2010 were obtained from 12 Disease Surveillance Point (DSP) sites in four provinces of China. Death data from all causes and respiratory disease, chronic obstructive pulmonary disease (COPD), pneumonia and influenza, circulatory disease, and ischemic heart disease, were stratified by year, month of death occurrence and sex, seven age groups, and summarized by descriptive statistics. The mean annual mortality rates of the selected 12 DSP sites in the southernmost provinces of China were 543.9 (range: 423.9–593.6) deaths per 100,000 population. The death rates show that noted sex differences were higher in the male population for all-cause, COPD and circulatory diseases. Pneumonia and influenza death rates present a different sex- and age-related distribution, with higher rates in male aged 65–74 years; whereas the death rates were opposite in elderly aged ≥75 years, and relatively higher in young children. This study had practical implications for recommending target groups for public health interventions.