Current situation and influence factors of suicidal self-injurious behavior in teenagers in Guangdong / 上海预防医学

Objective:To investigate the current situation of suicidal self-injurious behavior in teenagers and analyze its influencing factors. Methods:From January to November 2020， a stratified sampling method was used to investigate 707 teenagers in Guangdong. The “questionnaire of health-related behaviors of Chinese teenagers” compiled by the Chinese Center for Disease Control and Prevention was used anonymously to investigate the current situation of suicidal self-injurious behavior of the teenagers. The chi-square test was used for univariate analysis， and logistic regression was used for multivariate analysis. Results:The incidence rate of suicidal self-injurious behavior was 14.57% （103/707）. It was 13.31% （45/338） in males， 15.72% （58/369） in females， 13.83% （48/347） in junior high school students and 15.28% （55/360） in senior high school students. There was no statistical significance in the incidence of suicidal self-injurious behavior of teenagers between different genders， different learning stages， smoking or not， asexual behavior or not， gambling or not， and fighting or not （all P>0.05）. The incidence of suicidal self-injurious behaviors in teenagers from single parent family， drunkenness， runaway， loneliness， under great study pressure， lovelorn， and mobile phone addiction was significantly higher （χ2=13.809， 10.852， 14.279， 11.451， 12.893， 22.905， 19.473， respectively. All P<0.001）. Logistic regression analysis showed that the following were main risk factors affecting the incidence of suicidal self-injurious behavior in teenagers： single parent family （OR=3.826， 95%CI： 1.402-7.501）， drunkenness （OR=3.903， 95%CI： 1.512-7.368）， runaway （OR=3.447， 95%CI： 1.669-7.715）， loneliness （OR=3.613， 95%CI： 1.504-7.697）， great study pressure （OR=3.712， 95%CI： 1.387-7.604）， lovelorn（OR=4.125， 95%CI： 1.516-8.117） and mobile phone addiction（OR=4.027， 95%CI： 1.499-7.984 （all P<0.001）. Conclusion:The incidence of suicidal self-injurious behavior in teenagers is not low in Guangdong， and targeted measures should be developed to screen and intervene based on the influencing factors.

Diastereoselective Synthesis of Polysubstituted Piperidines through Visible-Light-Driven Silylative Cyclization of Aza-1,6-Dienes: Experimental and DFT Studies.

A visible-light-driven radical silylative cyclization of aza-1,6-dienes featuring an acrylonitrile or acrylate moiety and an electron-neutral olefin was developed, which allows for stereoselective synthesis of densely functionalized piperidines in a highly atom-economical manner. Depending on the substitution pattern of the electron-neutral olefin, poor-to-excellent diastereoselectivity was observed. It was suggested that the 6-exo-trig cyclization was initiated by a chemoselective addition of silyl radical toward electron-deficient olefin and the geometry of the remaining olefin is closely associated with the cis-stereoselectivity. DFT calculations supported that a transition state with a cyano group locating at the axial position of the forming piperidine ring might be involved, in which either the increase of 1,3-diaxial repulsion or the lack of hydrogen bonding interaction will diminish diastereoselectivity.

Visible Light-Driven Radical trans-Hydrosilylation of Electron-Neutral and -Rich Alkenes with Tertiary and Secondary Hydrosilanes.

A visible light-driven radical hydrosilylation of electron-neutral and -rich alkenes has been investigated on the basis of a newly developed catalytic reaction system composed of eosin Y, thiol, and base additives. A variety of linear and cyclic alkenes with different substitution patterns were found to undergo such metal-free hydrosilylation with tertiary and secondary hydrosilanes in a chemo-, regio-, and stereoselective manner. Comparison of the reactivity of diene compounds and late-stage hydrosilylation of steroid drugs were also explored. Deuterium labeling experiments reveal that a stepwise formation of C-Si and C-H bonds with a trans stereochemistry is preferred, in which the thiol may behave as a hydrogen atom transfer agent.

Radical Hydrosilylation of Alkynes Catalyzed by Eosin Y and Thiol under Visible Light Irradiation.

A visible light-promoted hydrosilylation of alkynes has been explored and achieved using 1 mol % organic dye Eosin Y as the photocatalyst and a catalytic amount of thiol as the radical quencher. The corresponding alkenylsilanes were provided with high regio- and stereoselectivites in the reactions of various terminal and internal alkynes. The experimental evidence shows that the reaction is preferentially initiated by a single electron transfer process, and a photoredox pathway is suggested.