Psychological Capital and Its Factors as Mediators Between Interpersonal Sensitivity and Depressive Symptoms Among Chinese Undergraduates.

Purpose: Current interpersonal sensitivity among college students is easily linked to mood disorders such as anxiety, depression and other mood disorders. This study aims to examine the mediating role of psychological capital and its dimensions in the relationship between interpersonal sensitivity and depressive symptoms among undergraduates. Methods: The cross-sectional survey was conducted by using cluster stratified random sampling method across six Chinese universities between November and December 2022. The questionnaire consists of the Interpersonal Sensitivity sub-scale, the Patient Health Questionnaire, the Psychological Capital Questionnaire and the Socio-Demographic Feature Questionnaire. Results: A total of 2580 respondents participated in the survey, with the majority being females (69.73%) and an average age of 19.22±1.28 years. Descriptive and correlation analyses were performed using SPSS v24.0, while direct and indirect effects were analyzed using PROCESS v3.4 macro. The findings revealed that interpersonal sensitivity had a significant direct effect on depression symptoms among undergraduates (ß =0.416, 95% Boot CI [0.380, 0.453], p < 0.001) Additionally, psychological capital and its components were found to be negatively correlated with depression (p < 0.001). Further analysis demonstrated that hope, optimism, and resilience significantly mediated the association between interpersonal sensitivity and depressive symptoms (indirect effect: hope = 0.056, optimism = 0.074, resilience = 0.099; p < 0.001 for all). Conclusion: These results suggest that psychological capital, including its dimensions of hope, optimism, and resilience plays a crucial role in mitigating the negative effects of interpersonal sensitivity on depressive symptoms among undergraduates.

Bioconversion of volatile fatty acids derived from waste activated sludge into lipids by Cryptococcus curvatus.

Pure volatile fatty acid (VFA) solution derived from waste activated sludge (WAS) was used to produce microbial lipids as culture medium in this study, which aimed to realize the resource recovery of WAS and provide low-cost feedstock for biodiesel production simultaneously. Cryptococcus curvatus was selected among three oleaginous yeast to produce lipids with VFAs derived from WAS. In batch cultivation, lipid contents increased from 10.2% to 16.8% when carbon to nitrogen ratio increased from about 3.5 to 165 after removal of ammonia nitrogen by struvite precipitation. The lipid content further increased to 39.6% and the biomass increased from 1.56g/L to 4.53g/L after cultivation for five cycles using sequencing batch culture (SBC) strategy. The lipids produced from WAS-derived VFA solution contained nearly 50% of monounsaturated fatty acids, including palmitic acid, heptadecanoic acid, ginkgolic acid, stearic acid, oleic acid, and linoleic acid, which showed the adequacy of biodiesel production.