Sleep disorders and associated factors among Tibetan secondary school students in high altitude areas / 中国学校卫生

Objective@#To analyze the status of sleep disorders and their influencing factors among Tibetan secondary school students in high altitude areas in China, so as to provide a reference for the improvement and intervention of sleep quality among Tibetan secondary school students in high altitude areas.@*Methods@#From April to July, 2022, a questionnaire survey on demographic factors, sleep disorders, and lifestyle was conducted on 5 486 Tibetan secondary school students in the Lhasa, Shigatse, and Nagqu regions of Tibet, China, using stratified whole-group sampling. Descriptive statistics and Logistic regression analysis were used to analyze the sleep disorders of Tibetan secondary school students and their influencing factors.@*Results@#The average score of PSQI for Tibetan secondary school students at high altitude was (5.67±3.23), and the detection rate of sleep disorders (PSQI>7) was 24.72% . There were significant differences in the prevalence of sleep disorders among different grades ( χ 2=23.95, P <0.01). Logistic regression analysis showed that interpersonal sensitivity, depression, anxiety, academic stress, falling asleep after midnight, sleep environment, and parental sleep disorders were positively associated with the occurrence of sleep disorders among Tibetan secondary school students ( OR =2.74, 1.68, 2.62, 1.32, 2.02, 1.85, 2.61, 1.31, 2.19, 2.88, 4.91, 2.94, 2.51, 1.36, P <0.05).@*Conclusion@#Tibetan secondary school students in high altitude areas have poor sleep quality and widespread sleep disorder problems, which should be given intervention and improvement. Schools and families should give secondary school students more guidance on appropriate exercise, and reduce academic stress to improve sleep quality and ensure healthy physical and mental development for secondary school students.

A Green Roof Test Bed for Stormwater Management and Reduction of Urban Heat Island Effect in Singapore.

A green roof test bed, established at the Nanyang Technological University in Singapore, was used to investigate its benefit for storm water management and urban heat island effect mitigation. The system comprised 3 units, 2 in the form of vegetated roofs and the other a bare roof. The system was equipped with automatic monitoring devices for measuring the hydrological data. Continuous data monitoring on the roofs was conducted to evaluate the thermal and hydrological effects. The study shows that the green roof test bed can significantly reduce the roof surface temperature (by an average of 7.3ºC) and lower the ambient air temperature (by an average of 0.5ºC) when compared with a bare roof during day time hours (from 10:00 am to 4:00 pm). The ability to reduce and delay the peak runoff was demonstrated by using a typical rainfall event with 18 mm depth. The designed system is useful in evaluating both thermal and hydrological benefits of a green roof system in tropical areas and can offer guidance to local managers in mitigating the urban heat island effect and designing storm water management strategies.

Sodium nitrite preconditioning protects against ethanol-induced damage in human hepatoma SMMC-7721 cells / 药学学报

This study is to investigate the cytoprotective role of NaNO2 preconditioning against ethanol induced damage in human hepatoma SMMC-7721 cells. The cells were preconditioned with NaNO2 (0.25 mmol x L(-1)) for 24 hours or 4 weeks, and then exposed to ethanol (200 mmol x L(-1)) for additional 12 h and untreated cells served as control. Both temporal and chronic NaNO2 preconditioning could prevent ethanol elicited cytotoxicity as evidenced by thiazolyl blue (MTT). NaNO2 preconditioning also could inhibit ethanol-induced apoptosis, which was confirmed by FITC-Annexin V/PI flow cytometer and Hoechst 33258 and PI staining. Further, simultaneous NaNO2 preconditioning treatment along with ethanol showed protection against ethanol mediated cellular damage as indicated by significantly decreased levels of malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD) and catalase (CAT). Western blotting analysis revealed that in ethanol treated cells preconditioned with NaNO2, the HIF-1alpha and Bcl-2 increased obviously, while the expression of pro-apoptotic proteins, including Bax, Caspase-9, Caspase-3 decreased. The results showed that low doses of NaNO2 preconditioning resistant to ethanol-induced human hepatoma SMMC-7721 cells apoptosis, which mechanism may be related to increased expression of HIF-1alpha in the cells.