The Effect of Peer Relationships on Adolescent Loneliness: The Role of Psychological Resilience and the OXTR Gene.

Background: Based on the gene-environment interaction paradigm, this study explored the effect of peer relationships on adolescent loneliness and the role of psychological resilience and the oxytocin receptor gene (OXTR). Methods: A survey was conducted in a sample of 619 adolescents, and their oral cells were collected for DNA extraction and genotyping. Results: The results showed that (1) both peer relationships and psychological resilience significantly affected adolescent loneliness; (2) psychological resilience partially mediated the relationship between peer relationships and loneliness in adolescents; (3) OXTR gene rs53576 polymorphism moderated both the first and second half of the indirect pathway of the mediation model. Specifically, carriers of the rs53576 polymorphism A/A genotype showed a significantly enhanced effect of peer relationships on adolescent psychological resilience, while carriers of the rs53576 polymorphism G/G genotype showed a significantly enhanced effect of psychological resilience on adolescent loneliness. Conclusion: These findings helped elucidate the developmental mechanisms of adolescent loneliness in terms of peer relationships, psychological resilience, and OXTR gene polymorphisms.

A moderated mediation effects analysis was conducted to investigate the effect of peer relationships on adolescent loneliness and the role of psychological resilience and the oxytocin receptor gene (OXTR). The results revealed psychological resilience partially mediated the relationship between peer relationships and loneliness in adolescents; OXTR gene rs53576 polymorphism moderated both the first and second half of the indirect pathway of the mediation model. These findings helped elucidate the developmental mechanisms of adolescent loneliness in terms of peer relationships, psychological resilience, and OXTR gene polymorphisms.

The effect of life events on NSSI: the chain mediating effect of sleep disturbances and PLEs among Chinese college students.

This study aimed to explore the relationship between life events and non-suicidal self-injury (NSSI) in college students, as well as the mediating effect of sleep disturbances and psychotic-like experiences (PLEs). After excluding invalid questionnaires, 5,754 were retained, and the valid efficiency was 75.94%. The subjects were aged 16 to 29 years (M = 19.166; SD = 1.392), with 1,969 males (34.22%) and 3,785 females (65.78%). Life events, sleep disturbances, PLEs, and NSSI were assessed using standard scales. Data were analyzed by Pearson Correlation Analysis and bias-correction percentile Bootstrap method. The results show that (1) life events were significant positive predictors of NSSI, sleep disturbances, and PLEs; (2) sleep disturbances, PLEs, and the chain mediation between the two, were mediators between life events and NSSI. Life events are thus shown to be an important external factor influencing NSSI in university students, and this process is mediated through sleep disturbances, PLEs, and the chain between the two. Interventions for NSSI can therefore be made by improving college students' sleep quality and reducing PLEs.

Effect of In Situ NbC-Cr7C3@graphene/Fe Nanocomposite Inoculant Modification and Refinement on the Microstructure and Properties of W18Cr4V High-Speed Steel.

A novel graphene-coated nanocrystalline ceramic particle, iron-based composite inoculant was developed in this study to optimize the as-cast microstructure and mechanical properties of W18Cr4V high-speed steel (HSS). The effects of the composite inoculant on the microstructure, crystal structure, and mechanical properties of HSS were analyzed using transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The (002-) and (020) crystal planes of the Fe3C and Cr7C3 phases, respectively, were collinear at two points in the reciprocal space, indicating a coherent relationship between the Fe3C and Cr7C3 phases in the tempered modified HSS. This contributed to an improved non-uniform nucleation rate and refining of the HSS grains. The mechanical properties of the modified steel exhibited a general improvement. Specifically, the modification treatment enhanced the hardness of HSS from HRC 63.2 to 66.4 and the impact toughness by 48.3%.

Cumulative ecological risk and nonsuicidal self-injury in adolescents: The mediation of depression and the moderation of impulsiveness.

BACKGROUND: This study is based on the biosocial model of nonsuicidal self-injury (NSSI), to explore the effects of cumulative ecological risk on adolescents' NSSI, the mediating effect of depression between cumulative ecological risk and adolescents' NSSI, and the moderating role of impulsiveness in this mediating pathway. METHODS: A total of 16 508 adolescents, with 7903 males (47.9%), participated in the study and completed the Cumulative Ecological Risk Questionnaire, the Short Form of the Center for Epidemiological Studies Depression Scale, the Impulsiveness assessment, and the Nonsuicidal Self-Injury Scale. RESULTS: (1) There was a significant positive correlation between cumulative ecological risk, depression, impulsiveness, and NSSI; (2) cumulative ecological risk significantly predicted adolescents' NSSI; (3) depression had a mediating effect between cumulative ecological risk and adolescents' NSSI; and (4) impulsiveness moderated both the effects of cumulative ecological risk on adolescents' depression and NSSI and the effects of depression on NSSI in adolescents. CONCLUSIONS: Impulsiveness and depression are risk factors for adolescent NSSI and play a crucial role between cumulative ecological risk and NSSI in adolescents.

Serotonergic multilocus genetic variation moderates the association between interpersonal relationship and adolescent depressive symptoms.

BACKGROUND: Research suggests that genetic variants linked to serotonin functioning moderate the association between environmental stressors and depressive symptoms, but examining gene-environment interactions with single polymorphisms limits power. METHODS: A multilocus genetic profile score (MGPS) approach to measuring serotonergic multilocus genetic variation and examined interactions with interpersonal relationship, insomnia with depressive symptoms as outcomes in an adolescent sample (average age = 14.15 ± 0.63 years since first measurement; range: 13 to 15). RESULTS: (1) interpersonal relationship predicted adolescent depressive symptoms; (2) insomnia mediated the effect of interpersonal relationships on adolescent depressive symptoms; (3) the THP2 gene rs4570625 polymorphism G allele was a key risk factor for depressive symptom, and the MGPS moderated the effects of teacher-student relationship and insomnia on adolescent depressive symptom. Specifically, as the MGPS increased, the effects of insomnia on adolescent depressive symptom were enhanced; further, when the MGPS score increased, the effect of teacher-student relationship on depression showed a similar phenomenon with an increased slope and enhanced prediction; and (4) the results of sensitivity analysis showed that multilocus genetic interaction with the environment had a better explanatory power and stability for depression than single polymorphism studies. CONCLUSION: MGPS provides substantial power to examine gene-environmental interactions linked to affective outcomes among adolescents.

The relationship between family functioning and psychotic-like experiences of college students: Chain multiple mediating effects.

AIM: To explore the mechanism of the relationship between college students' family functioning and psychotic-like experiences, a chain multi-intermediary model is constructed to investigate the multiple mediating effects of interpersonal adaptation, sleep quality and loneliness on college students' family functioning and psychotic-like experiences. METHODS: Seven hundred seven college students in China were surveyed by using the Family Care Index Questionnaire, Loneliness Scale, Pittsburgh Sleep Quality Index Questionnaire, College Students' Interpersonal Adaptability Subscale and Community Assessment of Psychiatric Experiences. RESULTS: (a) The detection rate of psychotic-like experiences among college students is 72.14%, of which 6.93% reported frequent psychotic-like experiences; (b) There is a significant correlation between family functioning, sleep quality, loneliness, interpersonal adaptation and psychotic-like experiences of college students; (c) Interpersonal adaptation, loneliness and sleep quality of college students have chain multiple mediating effect in the relationship between family functioning and psychotic-like experiences. CONCLUSION: The results reveal the mechanism of the relationship between family functioning and psychotic-like experiences, which helps us to better understand how family functioning affects the occurrence and development of college students' psychotic-like experiences.

The Relationship of Family Functioning and Suicidal Ideation among Adolescents: The Mediating Role of Defeat and the Moderating Role of Meaning in Life.

OBJECTIVE: To investigate the relationship between family functioning and suicidal ideation among adolescents. METHOD: A total of 4515 junior and senior high school students were assessed using the Family APGAR, the Depressive Symptom Index-Suicidality Subscale, the Defeat Scale, and the Chinese Meaning in Life Questionnaire. RESULTS: This study found pairwise correlations between suicidal ideation, family functioning, defeat, and meaning in life. Specifically, family functioning was an influencing factor of adolescent suicidal ideation, and defeat was a mediator of the relationship between family functioning and adolescent suicidal ideation; meaning in life was found to be a moderator of the first half of the mediation process by defeat, that is, it moderated the influence of family functioning on adolescent defeat. CONCLUSIONS: This study demonstrated that the relationship between family functioning and adolescent suicidal ideation, as well as the influence of defeat and meaning in life on this relationship, constituted a moderated intermediary model. This finding has both theoretical and practical value for the implementation of a psychosocial model of adolescent suicide prevention and intervention.

Carbon fibers coated with graphene reinforced TiAl alloy composite with high strength and toughness.

To meet the more rigorous requirement in aerospace industry, recent studies on strengthening and toughening TiAl alloys mostly focus on high Nb addition, which inevitably bring in an increasing of density. In this study, a carbon fibers coated with graphene reinforced TiAl alloy composite was fabricated by powder metallurgy, melt spun and vacuum melting. This composite got remarkable mechanical properties combined with a prominent density reduction. In contrast with pure TiAl ingots, this sample exhibits an average fracture strain from 16% up to 26.27%, and an average strength from 1801 MPa up to 2312 MPa. Thus, we can achieve a new method to fabricate this low-density, good mechanical performance TiAl composite which could bring in more opportunities for application in aerospace industry.