[Influencing factors of suicidal ideation among men who have sex with men].

Objective: To investigate the prevalence of suicidal ideation among MSM, and to explore the influence of perceived social support and depression on suicidal ideation and the possible pathway. Methods: MSM who are ≥18 years, HIV-negative, and ever had sex with men (oral sex/anal sex) in the last year participated in is study. Cross-sectional survey and convenient sampling method were used to recruit MSM through a male social interaction platform Blued 7.5 software from December 2020 to March 2021, with a questionnaire survey. Demographic questionnaire, Perceived Social Support Questionnaire and Center for Epidemiologic Studies Depression Scale were employed to collect data. Mplus 8.3 was used for data analysis. Results: Among 1 394 eligible MSM participants, 25.7% (358/1 394) had suicidal ideation. Perceived social support could have a direct effect on suicidal ideation (ß=-0.11, P=0.009), and an indirect effect on suicidal ideation through depression (ß=-0.18, P<0.001). Conclusions: Suicidal ideation was found to be lower in MSM with a higher level of perceived social support and a lower level of depression. Using social media to improve MSM's perceived social support and reduce depressive symptoms might be an effective means to prevent suicidal ideation.

Measurement of Scars Using Structured-Light 3D Scanning in Forensic Practice.

ABSTRACT: Objective To validate the accuracy and reliability of structured-light three-dimensional （SL-3D） scanning in measuring the length and area of the regular and irregular scars on body surface and discuss its value in forensic practice. Methods The lengths of 30 cases of simulated linear scars and 50 cases of linear scars after injury were measured using soft ruler, vernier caliper + thin line method, and SL-3D scanning. The areas of 35 cases of simulated patchy scars and 15 cases of patchy scars after injury were measured using length × width, film tracing with coordinate paper method, pixel method, and SL-3D scanning, and then statistically analyzed. Results The differences between the length of the simulated linear scars measured by SL-3D scanning and standard length had no statistical significance. When simulated patchy scars and patchy scars after injury were measured with high surface curvature and large irregular areas, the differences between the results of SL-3D scanning measurement and the standard area had no statistical significance. When the length of 50 cases of linear scars after injury were measured using SL-3D scanning, the correlation coefficient between the measurement results of two different investigators was 0.998, and the correlation coefficient between the two measurement results by the same investigator was 1.000. The correlation coefficient between the results of SL-3D scanning and that of vernier caliper + thin line method was 0.996. Conclusion The three-dimensional information of the scars on the body surface can be acquired using SL-3D scanning. The measurement of the length and area of the scars is not influenced by the location of scars, curvature of surface, and human factors. The measurement results are accurate, reliable and has unique advantages.

Plastic responses in the metabolome and functional traits of maize plants to temperature variations.

Environmentally inducible phenotypic plasticity is a major player in plant responses to climate change. However, metabolic responses and their role in determining the phenotypic plasticity of plants that are subjected to temperature variations remain poorly understood. The metabolomic profiles and metabolite levels in the leaves of three maize inbred lines grown in different temperature conditions were examined with a nuclear magnetic resonance metabolomic technique. The relationship of functional traits to metabolome profiles and the metabolic mechanism underlying temperature variations were then explored. A comparative analysis showed that during heat and cold stress, maize plants shared common plastic responses in biomass accumulation, carbon, nitrogen, sugars, some amino acids and compatible solutes. We also found that the plastic response of maize plants to heat stress was different from that under cold stress, mainly involving biomass allocation, shikimate and its aromatic amino acid derivatives, and other non-polar metabolites. The plastic responsiveness of functional traits of maize lines to temperature variations was low, while the metabolic responsiveness in plasticity was high, indicating that functional and metabolic plasticity may play different roles in maize plant adaptation to temperature variations. A linear regression analysis revealed that the maize lines could adapt to growth temperature variations through the interrelation of plastic responses in the metabolomes and functional traits, such as biomass allocation and the status of carbon and nitrogen. We provide valuable insight into the plastic response strategy of maize plants to temperature variations that will permit the optimisation of crop cultivation in an increasingly variable environment.