Orthogonally crosslinked alginate conjugate thermogels with potential for cell encapsulation.

Hydrogels with more than one mode of crosslinking have gained interest due to improved control over hydrogel properties such as mechanical strength using multiple stimuli. In this work, sodium alginate was covalently conjugated onto thermoresponsive polyurethanes to prepare hybrid polymers (EPC-Alg) that are responsive to both temperature and Ca2+, forming orthogonally crosslinked hydrogels which are non-toxic to cells. Notably, the crosslinks are fully reversible, allowing for gel strength to be modulated via selective removal of either stimulus, or complete deconstruction of the hydrogel network by removing both stimuli. Higher alginate fractions increased the hydrophilicity and Ca2+ response of the EPC-Alg hydrogel, enabling tunable modulation of the thermal stability, stiffness and gelation temperatures. The EPC-Alg hydrogel could sustain protein release for a month and encapsulate neural spheroids with high cell viability after 7-day culture, demonstrating feasibility towards 3D cell encapsulation in cell-based biomedical applications such as cell encapsulation and cell therapy.

The Relationship Between Child Sexual Abuse and Sexual Dysfunction in Adults: A Meta-Analysis.

Child sexual abuse (CSA) has been recognized as a risk factor for sexual dysfunction and has attracted increasing attention. However, controversies remain regarding related research. The aim is to calculate the pooled effect size estimate for the correlation between CSA and sexual dysfunction in adults by meta-analysis. Five bibliographic databases (PubMed, Cochrane Library, Web of Science, Embase, and PsycINFO) were comprehensively searched to clarify the association between CSA and sexual dysfunction in adults. We used a fixed-effects model to determine the total pooled effect size estimate and reported odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Subgroup analysis, publication bias analysis, and sensitivity analysis were conducted. Adults who had a history of CSA experienced a higher proportion of sexual dysfunction than adults with no history of CSA (OR = 1.68, 95% CI [1.49, 1.87]). Subgroup analysis showed that women with a history of CSA reported a higher proportion of sexual dysfunction than men with a history of CSA (men: OR = 1.45, 95% CI [1.05, 1.84]; women: OR = 1.62, 95% CI [1.42, 1.83]). The estimates of the effect sizes differed substantially depending on the CSA and sexual dysfunction instruments that were used in each study and the region of each sample. This meta-analysis provides conclusive evidence of an association between CSA and sexual dysfunction in adults. Currently known interventions for the treatment of sexual dysfunction after CSA have only been evaluated in women, so specific interventions should be designed for men CSA survivors who experience sexual impairment.

Association between the dietary literacy of children's daily diet providers and school-age children's nutritional status and eating behaviours: a cross-sectional study.

BACKGROUND: Overweight and obesity rates have increased rapidly in Chinese school-age children, and previous studies have indicated that poor dietary literacy can lead to unhealthy eating behaviours. However, few studies have investigated the association between the dietary literacy of daily diet providers and the eating behaviours and nutritional status of school-age children raised by the providers. Thus, we aimed to explore this association. METHODS: We collected data on the eating behaviours and nutritional status of children in two primary schools in Anhui Province, as well as the dietary literacy of their daily diet providers. T-tests, one-way ANOVA, chi-square tests, and multiple linear regression were used to analyse the association. RESULTS: We found significant differences in the scores on the Questionnaire of Children's Daily Diet Providers' Dietary Literacy (QCDDPDL) by region, relationship with the child, age, and educational level of the daily diet provider (all p < .05). Moreover, the children in the low QCDDPDL score group were inclined to engage in unhealthy eating behaviours such as emotional undereating and overeating (p < .05). In addition, the incidence of overweight and obesity was higher in the low QCDDPDL attitude score group than in the high score group (p = .006). CONCLUSIONS: Our study showed that the dietary literacy of diet providers may influence children's health and eating behaviours. Improving the dietary literacy of diet providers may promote the health status and eating behaviours of school-age children.

Psychological Resilience Mediates the Association Between Childhood Maltreatment and Self-Harm Phenotype in Chinese Early Adolescents.

Self-harm (SH) increases significantly in early adolescence with great variability, and childhood maltreatment (CM) contributes to this increase. Understanding the developmental pathway from CM to SH could provide clues for SH prevention. This study used latent class analysis (LCA) to detect the phenotype of SH and explored the role of psychological resilience in the pathway from the CM to SH phenotype among 5724 early adolescents (52.5% male). Three interpretable phenotypes of SH were identified: low SH (57.8%), medium SH (29.0%), and high SH (13.2%). Furthermore, CM was positively associated with the SH phenotype, psychological resilience mediated the association between CM and the SH phenotype (all ps < 0.001), and a larger mediating effect was observed in the medium SH (22.41%). Our findings offer new perspectives that improving psychological resilience can be used as an efficient intervention to reduce the risk of SH among early adolescents who have experienced CM.

Childhood Adversity Phenotypes and Risky Health Behaviors among Chinese Adolescents: Extending the Concept of Adversity.

Objective: To present an approach to phenotyping ACEs and explore the association between ACEs and adolescent health risky behaviors based on the social context of China. Methods: Totally, 5,726 adolescents aged 12-18 years were investigated about their ACEs in the family, peer, school, and personal domains and the occurrence of six types of risky health behaviors (i.e., smoking, drinking, sexual intercourse, self-harm, and suicidal ideation and attempts). Latent class analysis (LCA) was used to explore the ACE patterns. Results: Six latent classes of ACEs were identified, including low adversity, school adversity, school adversity and peer victimization, peer victimization, maltreatment and peer victimization, and high adversity, and associated with risky health behaviors in adolescents. Being physically punished by a teacher, experiencing sexual abuse, and experiencing family trauma most strongly differentiated from the six ACE classes and were correlated with an increased risk for risky adolescent health behaviors. Conclusion: This study supports a positive association between ACEs and risky adolescent health behaviors. Peer victimization, school adversity and associated contexts need to be considered in future ACE studies.

Dynamic Grafting of Carboxylates onto Poly(Vinyl Alcohol) Polymers for Supramolecularly-Crosslinked Hydrogel Formation.

Supramolecular hydrogels have attracted considerable interest due to their unique stimuli-responsive and self-healing properties. However, these hydrogel systems are usually achieved by covalent grafting of supramolecular units onto the polymer backbone, which in turn limits their reprocessability. Herein, we prepared a supramolecular hydrogel system by forming dynamic covalent crosslinks between 4-carboxyphenylboronic acid (CPBA) and polyvinyl alcohol (PVA). The system was then further crosslinked with either calcium ions or branched polyethylenimine (PEI) to generate hydrogels with distinctly different properties. Incorporation of calcium ions resulted in the formation of hydrogels with higher storage modulus of 7290 Pa but without self-healing properties. On the other hand, PEI-crosslinked hydrogel (PVA-CPBA-PEI) exhibited >2000% critical strain value, demonstrated high stability over 52 days and showed sustained antibacterial effect. A combination of supramolecular interactions and dynamic covalent crosslinks can be an alternate strategy to fabricate next-generation hydrogel materials.

The effect of healthy dietary patterns on male semen quality: a systematic review and meta-analysis.

The incidence of infertility has recently risen. Semen quality is an important male fertility indicator, and dietary factors can affect semen quality. We conducted this systematic review and meta-analysis to determine the effects of healthy dietary patterns on semen quality. A literature search was conducted in 3 databases (Embase, Web of Science and PubMed) on August 21, 2021. The included cross-sectional studies examined the influence of the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and prudent diet patterns on semen quality parameters; six studies (1244 subjects) were included. By comparing high consumption with low consumption of healthy dietary patterns, the results of the meta-analysis showed significantly higher sperm concentrations (mean difference [MD] = 6.88 × 106 ml-1, 95% confidence interval [CI]: 1.26 × 106 ml-1-12.49 × 106 ml-1; P < 0.05), a significant increase in total sperm count (MD = 16.70 × 106, 95% CI: 2.37 × 106-31.03 × 106; P < 0.05), and a significant increase in progressive sperm motility (MD = 5.85%, 95% CI: 2.59%-9.12%; P < 0.01). The sperm concentration, progressive sperm motility, and total sperm count were significantly higher in men with higher versus lower consumption of healthy dietary patterns. However, the results must be interpreted with caution.

Injectable Hybrid-Crosslinked Hydrogels as Fatigue-Resistant and Shape-Stable Skin Depots.

Injectable hydrogels have gained considerable attention, but they are typically mechanically weak and subject to repeated physiological stresses in the body. Herein, we prepared polyurethane diacrylate (EPC-DA) hydrogels, which are injectable and can be photocrosslinked into fatigue-resistant implants. The mechanical properties can be tuned by changing photocrosslinking conditions, and the hybrid-crosslinked EPC-DA hydrogels exhibited high stability and sustained release properties. In contrast to common injectable hydrogels, EPC-DA hydrogels exhibited excellent antifatigue properties with >90% recovery during cyclic compression tests and showed shape stability after application of force and immersion in an aqueous buffer for 35 days. The EPC-DA hydrogel formed a shape-stable hydrogel depot in an ex vivo porcine skin model, with establishment of a temporary soft gel before in situ fixing by UV crosslinking. Hybrid crosslinking using injectable polymeric micelles or nanoparticles may be a general strategy for producing hydrogel implants resistant to physiological stresses.

Exploring the correlates of homicidal ideation in Chinese early adolescents: A network analysis.

BACKGROUND: Adolescent homicide rates have aroused global concern and better understanding of factors relating to homicidal ideation is critical. This study aimed to explore the correlates of homicidal ideation in a cross-sectional school-based sample of Chinese early adolescents. METHODS: The data were obtained from the cross-sectional project 'Health and Risky Behaviors among Middle School Students in Anhui Province, China', which was conducted in November 2020. The entire sample of 5724 middle school students who completed the questionnaires was included in the present study. Network analysis was employed to examine the correlates of homicidal ideation at three levels: individual (sex, academic performance, childhood trauma, aggression, anxiety, severe physical illness), family (family economic status, family violence, parental crime, parental mental illness, relationship with father, relationship with mother), and school (school-bullying victimization and perpetration, relationship with classmates, teacher support). Additionally, sensitivity analyses were performed to evaluate sex differences. RESULTS: In the whole sample, 11.7 % of students reported homicidal ideation in the past six months. Network analyses revealed that individual-level (childhood maltreatment, aggression and anxiety) and school-level (teacher support, school-bullying victimization and perpetration) factors were associated with homicidal ideation. Sensitivity analyses showed that homicidal ideation was associated with academic performance and school-bullying victimization in boys but not in girls, although the sex differences were not significant. LIMITATIONS: The cross-sectional design of this study limited the inference of causality. CONCLUSIONS: This study identified some correlates of homicidal ideation and provided some novel insights into homicide prevention and intervention in Chinese early adolescents.

Polyelectrolyte Hydrogels for Tissue Engineering and Regenerative Medicine.

Polyelectrolyte hydrogels are emerging materials for tissue engineering and regenerative medicine applications due to their tunable biochemical properties, electrical conductivity, biocompatibility and similar network structure to the extracellular matrix in mammalian bodies. In this review, representative polyelectrolyte hydrogels carrying anionic, cationic, ampholytic, zwitterionic and ionic liquid moieties are systemically cataloged to express their chemical structures and preparation strategies. Recent advance of polyelectrolyte hydrogels in tissue engineering and regenerative medicine for drug delivery, skin healing, bone regeneration, cardiac tissue repair and anti-biofouling coating are also highlighted. Eventually, the outlook and challenges of polyelectrolyte hydrogels and their biomedical material applications are also discussed to offer future directions.

Psychological adjustment mediating the relationship between childhood maltreatment and borderline personality features among Chinese early adolescents.

BACKGROUND: A strong link between childhood maltreatment (CM) and borderline personality features (BPF) has been consistently demonstrated. However, little is known about the role of psychological adjustment (PA) as a mediator of this relationship. The purpose of the study was to explore the mediating role of PA in the CM-BPF linkage in a large sample of early adolescents. METHODS: A total of 5724 students (mean age = 13.5, SD = 1.0) were recruited from three middle schools by using the multistage random cluster sampling method in Anhui Province, China. Participants were required to complete self-report questionnaires regarding CM experience, self-perceived PA and BPF. Mediation analyses were computed via structural equation modelling. RESULTS: CM victimization was positively associated with BPF, and individuals with lower levels of PA were more likely to present with BPF. Mediation analysis showed a significant indirect effect of CM on BPF via PA (effect = 0.047, 95 % CI: 0.035, 0.058). LIMITATION: The cross-sectional design of this study did not allow testing causality. The retrospective investigation of CM history could cause recall bias. CONCLUSIONS: PA partially mediates the relationship between CM and BPF. These findings have important implications for considering PA as a protective factor in this relationship.

Relationships among adverse childhood experience patterns, psychological resilience, self-esteem and depressive symptoms in Chinese adolescents: A serial multiple mediation model.

Adverse childhood experiences (ACEs) and adolescent depression are both prevalent social problems that can increase the risk of several negative health consequences throughout life. The original definition of ACEs misdirects the focus of intervention efforts for ACEs to only family dysfunction and parenting practices. We used a broader definition of ACEs and a latent class analysis (LCA) model to examine ACE patterns, aiming to overcome the shortcomings of cumulative and single adversity approaches based on the special social context of China. The data were derived from a middle school in Huaibei City of Anhui Province in 2019 and 2020, which was a prospective study involving 1687 junior high school students. At the initial evaluation (T1), ACEs, psychological resilience, self-esteem, and depressive symptoms were assessed by the students. At Time 2 (T2), the depressive symptoms of students were assessed. LCA and mediation analyses were conducted with Mplus version 8.2. The LCA identified the following three heterogeneous ACE classes: "low adversity" (36.4%), "moderate adversity" (44.2%), and "high adversity" (19.4%). The mediation analysis showed that the ACE patterns affected depressive symptoms through the following two mediation paths only in the moderate but not in the high adversity class: self-esteem alone and a path combining psychological resilience and self-esteem. Psychological resilience separately did not mediate the association between ACE patterns and depressive symptoms. To reduce depressive symptoms, interventions for students with ACEs need to improve self-esteem through many channels.

Bidirectional associations among school bullying, depressive symptoms and sleep problems in adolescents: A cross-lagged longitudinal approach.

BACKGROUND: Adolescence is a life stage with a high risk of depression, sleep disorders and school bullying. The aim of this study is to examine the longitudinal relationships between school bullying (bullying victimization and bullying perpetration), depressive symptoms and sleep problems among adolescents and to consider whether the direct pathways vary by gender. METHODS: The study included 1687 7th grade students (60.4% boys) recruited from a middle school in southeastern China. We collected self-reports of school bullying, depressive symptoms and sleep problems from 2019 (T1) and 2020 (T2) among adolescents. A series of gender-specified cross-lagged paths in a structural equation model was used for the primary analysis. RESULTS: The models revealed evidence for bidirectional associations between school bullying, depressive symptoms and sleep problems. Among girls, higher bullying perpetration at T1 predicted fewer sleep problems and depressive symptoms at T2, while bullying victimization significantly predicted poor quality of sleep and severe depressive symptoms. Furthermore, sleep problems at T1 positively predicted bullying perpetration and victimization at T2 in boys but not in girls. For both boys and girls, severe depressive symptoms significantly predicted more victimization and sleep problems, and sleep problems were positively associated with depressive symptoms. LIMITATIONS: The sample is unrepresentative, as it is from only one middle school. CONCLUSIONS: Our findings highlight that school bullying, depressive symptoms and sleep problems were interrelated across time and that acknowledging gender differences is important.

Childhood trauma and depression in college students: Mediating and moderating effects of psychological resilience.

PURPOSE: Not all young people who have experienced childhood abuse and neglect will become depressed or have the same degree of depression. Psychological resilience may probably lead to part of the difference according to previous studies. To observe the association between childhood abuse and neglect and depression and analyze whether psychological resilience has mediating and moderating effects on this association. METHODS: A cross-sectional sampling with a self-report questionnaire used to measure childhood abuse and neglect, psychological resilience, and depression of college students was conducted in four universities in Hefei City, in October 2018. SPSS PROCESS was used to test the hypotheses of mediating and moderating effects. RESULTS: Among 4034 students, 58.1% were boys and 41.9% were girls, the average age was 20.4 years (SD = 1.4). A positive association between childhood abuse and neglect and depression was found in the population, whereas negative relationships between psychological resilience and depression, and childhood abuse and neglect were observed (r = 0.251, -0.477, and -0.196, respectively, p < 0.001). For the mediating effect of psychological resilience, the 1000-sample bootstrap demonstrated that the indirect effect was statistically significant (ß = 0.073, 95% CI: 0.057-0.092). For the moderating effect, R-square increased because the interaction effect was statistically significant (ΔR2 = 0.008, p < 0.001). CONCLUSIONS: Our study supported the conclusion of previous studies that psychological resilience mediates and moderates the process of depression. Future research can further reveal the role of psychological resilience by examining different types of childhood abuse and neglect.

Childhood abuse and borderline personality disorder features in Chinese undergraduates: the role of self-esteem and resilience.

BACKGROUND: Although childhood abuse is considered to be related to borderline personality disorder (BPD), few studies have elaborated on the mediating role of self-esteem and resilience in it. Thus, the present study aimed to explore the potential mediating role of resilience and self-esteem between childhood abuse and BPD. METHODS: This cross-sectional study was conducted with 4034 college students in Anhui Province, China. Participants were asked to complete Chinese versions of the following instruments: Childhood Trauma Questionnaire-Short Form (CTQ-SF), Mclean Screening Instrument for Borderline Personality Disorder (MSI-BPD), Connor-Davidson Resilience Scale (CD-RISC), and Rosenberg Self-Esteem Scale (RSES). Structural equation modeling (SEM) was used to test the mediation effects. RESULTS: Resilience and self-esteem were found to be mediators of all three types of childhood abuse (emotional abuse, physical abuse and sexual abuse) when the types were examined separately; however, when all three types of childhood abuse were entered into the model simultaneously, neither the indirect effects nor direct effects of physical abuse or sexual abuse were found to be significant, only the association between emotional abuse and BPD features was partially mediated by resilience and self-esteem. CONCLUSIONS: Self-esteem and resilience mediate the links between childhood abuse and BPD features, and emotional abuse is uniquely associated with BPD features.

Prevalence of anxiety symptom and depressive symptom among college students during COVID-19 pandemic: A meta-analysis.

BACKGROUND: The global pandemic of COVID-19 has brought huge changes to people's lifestyles, college students have also been affected seriously. Evidence about these significant changes indicated that college students were more prone to feel anxious and depressed. To derive a precise assessment of the prevalence of anxiety symptom and depressive symptom among college students worldwide, we conducted this meta-analysis. METHODS: Based on the guidance of PRISMA, literature was searched in Pubmed, Web of Science, Embase, and PsycArticles (last search November 6, 2020). These articles after the screening were analyzed by a random-effects model to estimate the pooled prevalence of anxiety symptom and depressive symptom. Also, subgroup analysis, sensitivity analysis, and publication bias were performed in this meta-analysis. RESULTS: The results showed that the pooled anxiety symptom prevalence was 31% (95% CI: 23-39%), pooled depressive symptom prevalence was 34% (95% CI: 27-41%). Subgroup analysis showed that the prevalence of anxiety symptom and depressive symptom among different countries' college students were different, and the pooled depressive symptom prevalence of females was higher compared with males. LIMITATIONS: The prevalence of anxiety symptom and depressive symptom in worldwide college students could be better assessed by a standard and reliable questionnaire. CONCLUSIONS: The results suggest that the prevalence of anxiety symptom and depressive symptom during the COVID-19 pandemic is relatively high. Except for interventions that should be taken to control the pandemic urgently, mental health services are also needed to decrease the risk of anxiety and depression among college students.

Synthesis of vinyl iodide chain-end polymers via organocatalyzed chain-end transformation.

In the presence of alkynes (CH[triple bond, length as m-dash]C-R2), iodide chain-end polymers (Polymer-I) were successfully transformed to vinyl iodide chain-end polymers (polymer-CH[double bond, length as m-dash]CR2-I) in a single step via organocatalysis. This reaction is completely metal-free and easy to carry out without using special reagents or special conditions. The polymers encompassing polyacrylates and polymethacrylate, and additional functionalities (e.g., OH and CF3) were also incorporated into the R2 moiety. The obtained Polymer-CH[double bond, length as m-dash]CR2-I further served as a useful precursor for copper-catalyzed cross-coupling reactions with various thiols (R3-SH) to yield vinyl sulfide chain-end polymers (polymer-CH[double bond, length as m-dash]CR2-SR3) with various R3 moieties. Interestingly, under selected conditions, this organocatalysis also offered block-like copolymers containing a conjugated oligo-alkyne segment and a non-conjugated polyacrylate segment. Exploiting the unique structure, the block-like copolymer was used as an efficient dispersant of carbon nanotubes.

Association between sexual abuse victimization during the life course and suicidal behaviors in male and female college students in China: Timing, duration, types and patterns.

BACKGROUND: A certain link between sexual abuse (SA) victimization and suicidal behaviors has been confirmed, but it remains unclear whether this association varies with regard to SA characteristics and gender. METHODS: Participants were 4034 college students drawn from a cross-sectional study conducted in Hefei, China. Gender-stratified latent class analysis (LCA) and logistic regression models were used to examine the relationships between timing, duration, types and patterns of SA victimization and suicidal behaviors. RESULTS: For the males, SA in the elementary school or earlier period was associated with suicidal ideation (OR: 3.29, 95%CI: 2.20-5.38), plans (OR: 3.44, 95% CI: 1.54-7.77) and preparations (OR:3.05, 95% CI: 1.19-7.74). All types of SA were significantly associated with the four types of suicidal behaviors. Dose-response relationship and cumulative effect were found between duration, types of SA victimization and suicidal behaviors. Three latent classes of SA victimization were identified for males and females, respectively. For males, the "moderate SA" class and "persistent SA" class were associated with the four types of suicidal behaviors. For the females, SA during the university period was associated with suicidal ideation (OR: 2.47, 95% CI: 1.24-4.93). Only suicidal ideation was associated with the "moderate SA" class. LIMITATIONS: The cross-sectional survey design did not allow to conclude any causality. CONCLUSIONS: The relationship between SA victimization and suicidal behaviors varies in terms of SA victimization characteristics and the relationships were stronger in males than in females.