Objective: To investigate electronic cigarette (e-cigarette) use and its influencing factors among junior high school students of health promotion schools in Xihu District, Hangzhou City, so as to provide insights into school-based tobacco control. Methods: Grade 1 to 3 junior high school students of health promotion schools in Xihu District were recruited using a multi-stage stratified cluster sampling method from September to December, 2021. The participants' demographic features, e-cigarette use and exposure to tobacco advertising were collected using the Chinese version of the Global Youth Tobacco Survey, and the factors affecting the intention to use e-cigarettes were identified using a multivariable logistic regression model. Results: The 1 677 respondents included 875 boys (52.18%) and 802 girls (47.82%), and grade 1 to 3 junior high school students consisted of 33.93%, 35.00% and 31.07% of all respondents, respectively. There were 1 461 students that had heard of e-cigarettes (87.12%), 101 students with intention to use e-cigarettes (6.02%), and 24 current users (1.43%). Multivariable logistic regression analysis identified living in rural areas (OR=2.364, 95%CI: 1.442-3.875), having close friends that were smokers (OR=5.614, 95%CI: 3.404-9.258), having seen smoking via TV, video or movie in the past 30 days (OR=2.106, 95%CI: 1.259-3.523), having received free tobacco products (OR=3.887, 95%CI: 1.172-12.894), considering e-cigarettes as nicotine-free (OR=208.442, 95%CI: 55.713-779.856), and considering smoking making comfortable at party (OR=4.534, 95%CI: 1.853-11.090) as factors affecting intention to use e-cigarettes. There were 38.04% (638/1 677) of junior high school students with exposure to advertisements for e-cigarettes and related products, and stores, supermarkets, convenience stores, grocery, e-cigarette experience stores or offline retail stores were the primary places to contact e-cigarettes and related products. Conclusions The percentage of intention to use e-cigarettes was low among junior high school students of health promotion schools in Xihu District in 2021, and their intention to use e-cigarettes was mainly affected by close friends' smoking status and personal recognition.

Objective To study the effect of autophagy regulation on hypoxia/reoxygenation injury(H/RI)in mouse spermatogonia,and to explore the effect of autophagy on ischemia-reperfusion injury(IRI)in mouse testicular tissue.Methods The mouse spermatogonial cell line GC1 spg was used as the research object to construct the H/RI model.Rapamycin(RAPA)and 3-methyladenine(3-MA)were used as autophagy ago-nists and inhibitors.The control group,the model group,the autophagy agonist intervention group(H/RI+autophagy agonist intervention),and the autophagy inhibitor intervention group(H/RI+autophagy inhibitor intervention)were set up.The cells proliferation ability of each group was detected by methyl thiazol tetrazoli-um(MTT)method.The release level of reactive oxygen species(ROS)and apoptosis level of each group were detected by flow cytometry.The expression levels of autophagy-related gene Beclin1 and apoptosis-relat-ed genes Bcl-2 and Bax mRNA in each group were detected by real-time fluorescence quantitative PCR(qPCR).The expression levels of autophagy-related proteins LC3-Ⅰ,LC3-Ⅱ,Beclin1,p62 and apoptosis-relat-ed proteins Bcl-2,Bax,caspase-3 in each group were detected by Western blot.Results Compared with the control group,the proliferation abiliy,the expression levels of Beclin1 and Bcl-2 mRNA in the model group were significantly decreased(P＜0.01),the relative expression levels of p62 and Bcl-2 proteins were significantly decreased(P＜0.01).The ROS level,apoptosis rate and the mRNA expression level of Bax were significantly increased(P＜0.01),and the protein expresion levels of Beclin1,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰ were significantly increased(P＜0.01).Compared with the model group,the cell proliferation a-bility,the expression levels of Beclin1 and Bcl-2 mRNA in the autophagy agonist intervention group were the protein ratio of significantly increased(P＜0.01),the protein expression levels of Beclin1 and Bcl-2 and the protein ration of LC3-Ⅱ/LC3-Ⅰ were significantly increased(P＜0.01).The ROS level,apoptosis rate and the expression level of Bax mRNA were significantly decreased(P＜0.01),and the protein expression levels of p62,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰ were significantly decreased(P＜0.01).Com-pared with the model group,the cell proliferation ability,the mRNA expression levels of Beclin1 and Bcl-2 in the autophagy inhibitor intervention group were significantly decreased(P＜0.01),the protein expression lev-els of Beclin1 and Bcl-2 protein were significantly decreased(P＜0.01).The ROS level,apoptosis rate and the mRNA expression level of Bax were significantly increased(P＜0.01),and the protein expression levels of p62,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰwere significantly iecreased(P＜0.01).Conclusion Enhanced au-tophagy can inhibit apoptosis of spermatogonia and repair H/RI in mice,which provides a theoretical basis for the treatment of testicular tissue IRI.