OBJECTIVES: Non-suicidal self-injury (NSSI) is a common mental health and behavioral issue among adolescents. This study aims to investigate the developmental trajectory of adolescent NSSI and gender differences, providing a foundation for better prevention and intervention. METHODS: A longitudinal study was conducted using the Adolescent Self-Injury Scale (ASIS) in a cohort of 1 042 junior high school students from 3 middle schools in Zhangjiajie, Hunan Province. Participants were surveyed 3 times at 6-month intervals. A latent growth curve model was constructed using Mplus8.0 to examine the development trajectory of NSSI, and multi-group comparisons were used to assess gender differences. RESULTS: Detection rates of NSSI at the 3 time points were 43.95%, 44.43%, and 38.36%, respectively. Mean of the intercept factor of the LGCM for adolescent NSSI behavior was 9.540 (P<0.001), and the mean slope was -2.297 (P<0.001). Both the variances of the intercept (σ²=169.431, P<0.001) and slope (σ²=141.981, P<0.001) were significant, with a significant negative correlation between intercept and slope (r=-0.559, P<0.001). There were no statistically significant gender differences in initial level or rate of change of NSSI behaviors (P>0.05). CONCLUSIONS NSSI is relatively prevalent among adolescents, with female adolescents experiencing more severe NSSI. Individual differences exist in both the initial level and rate of change of NSSI, and overall, adolescent NSSI shows a decreasing trend over time. No significant gender differences were found in the trajectory of change.
Humans ; Self-Injurious Behavior/psychology* ; Adolescent ; Male ; Female ; Longitudinal Studies ; Sex Factors ; Adolescent Behavior/psychology* ; China/epidemiology* ; Surveys and Questionnaires ; Students/psychology*

Objective To compare the genetic barriers to development of primary mutations related to drug resistance to protease inhibitors (PI), nucleioside reverse transcriptase inhibitors ( NRTI ), and non-nucleioside reverse transcriptase inhibitors ( NNRTI ) among human immunodeficiency virus (HIV)-1 CRF01_AE, CRF07_BC, and CRF08_BC strains, and to understand the difference of varying patterns of drug resistance related mutations within these subtypes. Methods One hundred and ninety naive HIV-positive subjects from Nanning City and Liuzhou City, Guangxi Zhuang Autonomous Region, were recruited. Peripheral blood samples were collected from all participants. HIV-1 RNAs were extracted from plasma, and the pol regions were amplified and sequenced. Sequences were subjected to phylogenetic analysis to determine the subtypes of HIV-1 isolates. Nucleotide transitions and transversions were counted for each primary mutation in these sequences. According to the phenomena that transitions occur on average 2. 5 times frequently than transversions, each transition was scored as 1, and each transversion scored as 2. 5. The sum of the scores for a particular substitution was calculated, and this value was taken as the genetic barrier to development of this mutation. Then, the differences of genetic barriers among the subtypes were assessed by Kruskal-Wallis test and Nemenyi test. Results A total of 123 sequences of CRF01_AE,CRF07_BC and CRF08_BC strains were selected. CRF08_BC had a lower genetic barrier for T/S69Dsubstitution than CRF01_AE and CRF07_BC (χ2 =107. 501, P＜0.01), while CRF01_AE and CRF07_BC had lower genetic barriers for V118I and L210W substitution than CRF08_BC. In addition,CRF07_BC had a decreased genetic barrier for V106M compared with CRF01_AE and CRF08_BC.Conclusions In the presence of the same selective pressure, subtypes CRF01_AE and CRF07_BC may be more likely to develop V118I and L210W substitution than CRF08_BC. However, CRF08_BC may be more likely to develop T/S69D substitution than CRF01_AE and CRF07_BC. Meanwhile, CRF07_BC may be easier to develop V106M substitution than CRF01_AE and CRF08_BC.