Factor structure and measurement invariance of the Depression anxiety stress scale (DASS-21) in Chinese left-behind and non-left-behind children: an exploratory structural equation modeling approach.

BACKGROUND: Comprehensive data has shown that adolescents often suffer from depression, anxiety, and low self-esteem, and are in a particularly fragile stage of psychological, physiological, and social development. Left-behind children in particular tend to have significantly higher, state anxiety and depression compared to non-left-behind children. The Depression, Anxiety, and Stress Scale (DASS-21) is an effective tool for evaluating depression, anxiety, and stress, and is used to measure levels of depression, anxiety, and stress in groups from a variety of backgrounds. The purpose of this study was to determine the effectiveness, reliability, and measurement invariance of the DASS-21 in Chinese left-behind children. METHOD: The test and re-test method was used (N = 676), and the exploratory structural equation model (Mplus v.8.3) used to verify basic measurement models. For measurement invariance, the configural, weak, strong, and strict models were tested. The reliability of the DASS-21 was also tested using the collected data. RESULTS: Analysis results showed that the DASS-21 had a stable three-factor structure in the sample of left-behind children in China. The measurement invariance test showed that gender and time not only had strong invariance, but also strict invariance. The results of cross left and non-left invariance indicated a lack of strict invariance. Finally, the McDonald's omega coefficient of the DASS-21 total scale was 0.864, and the internal consistency of each subscale was also good. CONCLUSIONS: The DASS-21 is shown to be an effective and reliable tool for measuring depression, anxiety and stress in Chinese left-behind children.

Facile Approach for the Potential Large-Scale Production of Polylactide Nanofiber Membranes with Enhanced Hydrophilic Properties.

Polylactide (PLA) nanofiber membranes with enhanced hydrophilic properties were prepared through electrospinning. As a result of their poor hydrophilic properties, common PLA nanofibers have poor hygroscopicity and separation efficiency when used as oil-water separation materials. In this research, cellulose diacetate (CDA) was used to improve the hydrophilic properties of PLA. The PLA/CDA blends were successfully electrospun to obtain nanofiber membranes with excellent hydrophilic properties and biodegradability. The effects of the additional amount of CDA on the surface morphology, crystalline structure, and hydrophilic properties of the PLA nanofiber membranes were investigated. The water flux of the PLA nanofiber membranes modified with different CDA amounts was also analyzed. The addition of CDA improved the hygroscopicity of the blended PLA membranes; the water contact angle of the PLA/CDA (6/4) fiber membrane was 97.8°, whereas that of the pure PLA fiber membrane was 134.9°. The addition of CDA enhanced hydrophilicity because it tended to decrease the diameter of PLA fibers and thus increased the specific surface area of the membranes. Blending PLA with CDA had no significant effect on the crystalline structure of the PLA fiber membranes. However, the tensile properties of the PLA/CDA nanofiber membranes worsened due to the poor compatibility between PLA and CDA. Interestingly, CDA endowed the nanofiber membranes with improved water flux. The water flux of the PLA/CDA (8/2) nanofiber membrane was 28,540.81 L/m2·h, which was considerably higher than that of the pure PLA fiber membrane (387.47 L/m2·h). The PLA/CDA nanofiber membranes can be feasibly applied as an environmentally friendly oil-water separation material because of their improved hydrophilic properties and excellent biodegradability.