Objective: This study aimed to explore the relationship between childhood sexual abuse (CSA) and sexual orientation among college students, and to explore possible sex difference. Methods: By using multi-stage stratified cluster sampling method, 4 034 students were selected from 4 college schools. Self-made questionnaire was used to collect the demographic information, CSA experiences and sexual orientation. Logistic regression models were conducted to examine sex differences in the relationship between different types and timing of CSA and sexual orientation. Results: The reporting rates of heterosexual, homosexual, bisexual and asexual orientation of college students were 93.2%, 0.7%, 3.7% and 2.4%, respectively. For males, contact CSA (OR=14.70, 95%CI=5.73-37.72), both contact and noncontact CSA (OR=4.33,95%CI=1.91-9.84) in elementary school or earlier were associated with sexual orientaion. non-contact CSA (OR=4.20, 95%CI=2.21-7.98), both contact and noncontact CSA (OR=3.57, 95%CI=1.65-7.70) in middle school were related to sexual orientation. However, for females, non-contact CSA (OR=1.78, 95%CI=1.02-3.13) and both contact and non-contact CSA (OR=3.13, 95%CI=1.35-7.23) in elementary school or earlier were associated with sexual orientation. Conclusion CSA experiences are associated with sexual orientation in sex-specific manner, with significant stronger association among males.

Chronic refractory wounds have been a challenge for clinical treatment because of their diverse causative factors and complex pathological processes, long healing times, and high treatment costs. The microenvironment of the wound surface includes the external microenvironment of the periwound surface, the internal microenvironment of the wound surface, and subsurface physiological structures. Research on clinical treatment strategies based on the microenvironment of chronic refractory wounds continues to innovate and make progress. Hydrogels have the advantages of high-water content, adjustable performance, good biocompatibility, and similarity to extracellular matrix. The ability of hydrogels to load drugs and their modification to confer excellent tissue adhesion, antibacterial, antioxidant, and modulation of inflammatory factor expression can be used to achieve a multi-factor response and modulation of the physical, chemical, and biological aspects of the trauma microenvironment. Therefore, hydrogels have outstanding advantages and clinical application prospects in the repair of chronic, difficult-to-heal wounds. In this review paper, the characteristics and etiology of chronic refractory wounds were introduced, and the classification of microenvironment-responsive hydrogels for chronic refractory wounds and their application in the repair of refractory wounds were reviewed. Besides, the shortcomings of current hydrogels were discussed, and an outlook was proposed.

Abstract Adolescent cyberbullying refers to adolescents who are subjected to offensive and violent behavior in social network environments through electronic technologies. Due to the anonymity of the Internet and the rapidity of transmission, cyberbullying has a serious and far reaching impact on the physical and mental health of teenagers. With the development of information technology, various forms of cyberbullying have emerged, and the formation mechanism and influencing factors of cyberbullying are diverse and complex. This article systematically reviews the research progress in cyberbullying by evaluating the epidemic characteristics, influencing factors, and related theoretical models that are relevant to adolescents, so as to provide a referential framework to build a public health system that can prevent cyberbullying in families, schools, and society.

Objective: To explore the mediating effect of depressive symptom on the relationship between peer bullying patterns and suicidal ideation, and to provide suggestions for school bullying and suicide prevention for adolescents. Methods: A follow up cohort was established in a junior middle school in Suixi County, Anhui Province in September 2019 (T1). The first follow up was conducted in September 2020 (T2). A total of 1 687 junior high school students participated in this study. Self designed peer bullying questionnaire,center for Epidemiological Studies Depression Scale for children,and questions regarding suicide related behaviors were administered. Results: Prevalence of suicidal ideation, victimization and bullying were 28.3%, 27.0% and 24.4%, respectively. The latent class analysis(LCA) identified three heterogeneous peer bullying classes: low aggressive victims(71.4%), high aggressive victims(3.3%), high verbal and relational aggressive victims( 25.3 %). The low aggressive victims class was used as the reference group, T1 depressive symptom mediated the association between high aggressive victims(mediating effect=0.43, P < 0.05 ), high verbal and relational aggressive victims class (mediating effect= 0.29 , P <0.05) and T2 suicidal ideation. Conclusion Depressive symptom plays a mediating role in the relationship between peer bullying and suicidal ideation. In order to prevent peer bullying and suicide related psychological behaviors of adolescents, educators should pay attention to adolescents mental health when formulating corresponding measures.

Objective: To explore the association between acute stress response during the outbreak of COVID 19 and peer bullying behaviors during the normalized management of COVID 19 among middle school students, and to provide a basis for developing relevant measures for peer bullying prevention. Methods: In December 2020, a total of 2 219 students from two junior middle schools in South Anhui(Xuancheng City) and North Anhui(Huaibei City), were selected to participate in this study by using the cluster sampling method. The occurrence of verbal bullying, relational bullying, physical bullying and cyberbullying behaviors among victims and perpetrators of bullying, and self rated acute stress response during the outbreak of COVID 19 (social isolation) were investigated. Multiple Logistic regression models were conducted to explore the relationship between different levels of acute stress response during the COVID 19 outbreak and peer bullying behaviors among middle school students. Results: The reported rate of peer bullying, being bullied by others and bullying others during the COVID19 normalized management were 65.8%, 63.8% and 27.1%, respectively. The reporting rate of verbal bullying victimization was the highest (54.8%) and cyberbullying others was the lowest (4.6%). The mean score of acute stress response among middle school students during the COVID 19 outbreak was (6.50±1.67). Except for physically bullying others, the reported rate of other bullying behaviors was the highest in the high level acute stress response group ( P <0.05). Multiple Logistic regression models showed that high levels of acute stress response were associated with high risk of verbal bullying victimization ( OR =1.38), relational bullying victimization ( OR =2.28), physical bullying victimization ( OR =1.87) and cyberbullying victimization ( OR =2.30) after adjusting for related confounders. In the high level acute stress response group, verbal bullying ( OR =1.80), relational bullying ( OR =1.99), physical bullying ( OR =1.76) and cyberbullying ( OR =2.32) had higher risks of bullying others than in the low level acute stress response group ( P <0.05). Conclusion High levels of acute stress response are associated with different peer bullying behaviors, with stronger associations with cyberbullying.

Objective: To explore the relationship between different types of bullying behavior and depressive symptoms among adolescents, and to provide scientific basis for further prevention of peer bullying. Methods: Based on the follow up data of 1 687 adolescents from Huaibei City, Anhui Province in September 2019 (T1) and September 2020 (T2), the autoregressive cross lagged analysis was employed to explore the relationship between different types of peer bullying and depressive symptoms. Results: The scores of bullying behaviors (physical bullying, verbal bullying, relational bullying and cyber bullying) and depressive symptoms at T2 were lower than those at T1,and the differences were statistically significant ( t =13.60, 8.61,7.24,3.76,8.29, P <0.01). There was a positive correlation between bullying behavior and depressive symptoms ( P <0.01). The results from cross lagged regression analysis showed that physical, verbal, relational and cyber bullying at T1 could positively predict depressive symptoms at T2 ( β = 0.06 , 0.04, 0.12, 0.05), and physical, verbal, relational and cyber bullying at T1 could positively predict depressive symptoms at T2 ( β =0.07, 0.10, 0.13, 0.10) ( P <0.05). Conclusion There were bidirectional associations between adolescent peer bullying and depressive symptoms.

AIM:To investigate the therapeutic effect of menstrual blood-derived endometrial stem cells(MenSCs)on chemotherapy-induced intestinal mucositis and flora disorders in mice,and to explore the potential mecha-nism.METHODS:The mice were randomly divided into 3 groups including normal treatment,cisplatin(Cis)treatment and Cis+MenSC treatment,with 10 mice in each group.To induce intestinal mucositis,the mice were treated with Cis(2 mg·kg-1·d-1)by intraperitoneal injection for 5 consecutive days.Control mice for normal group were received equal vol-umes of normal saline.For Cis+MenSC treatment,MenSCs(1×106)was transplanted into the mice of Cis treated mice through tail vein.The performances and weight changes of mice were examined during the experiment.After the treat-ment,the small intestine and colon were isolated for subsequent HE staining,the ratio of F4/80 and IL-6 positive cells in small intestine were detected by immunohistochemical staining,and the expression of tight junction,inflammation and apoptosis related proteins was detected by Western blot.16S rDNA amplicon sequencing was performed to detect the diver-sity and richness of intestinal flora in mice.RESULTS:Compared to the Cis group,the MenSCs-treated mice showed sig-nificantly increased body weight,relieved intestinal lymphocytes infiltration,alleviated intestinal villous edema,and or-derly arranged glands in intestinal tissues.Further analysis indicated that MenSCs transplantation significantly up-regulat-ed the expression of intestinal tight junction related proteins ZO-1 and occludin in Cis-treated mice(P＜0.05).Subse-quently,MenSCs transplantation significantly inhibited the macrophages infiltration in intestinal tissues(P＜0.01),down-regulated the expression of pro-inflammatory factors IL-1 and IL-6 and pro-apoptotic protein Bax(P＜0.01),while up-regu-lated anti-inflammatory factor IL-10 and anti-apoptotic protein Bcl-2(P＜0.01).Additionally,further microflora sequenc-ing indicated that MenSCs transplantation prevented mice from Cis-induced intestinal flora disorder,and significantly re-duced the abundance of harmful bacteria such as isenbergiella tayi and Anaerotruncus colihominis(P＜0.01).At the same time,the abundance of beneficial bacteria Lactobacillus apodemi was increased(P＜0.05),thereby restoring the composi-tion and function of healthy intestinal flora.CONCLUSION:MenSCs transplantation alleviates the chemotherapy-in-duced damage of intestinal structure,relieves the symptoms of chemotherapy-induced mucositis and restores the homeosta-sis of intestinal flora in mice.

Objective To investigate the expression of Nanog and its regulatory relationship with MMP-2/MMP-9 proteins in esophageal squamous cell carcinoma(ESCC).Methods We detected Nanog and MMP-2/MMP-9 protein expressions in 127 ESCC tissues and 82 adjacent normal tissues using immunohistochemistry and explored their correlations with the clinicopathological parameters and prognosis of the patients.GEO database was utilized to analyze the pathways enriched with the stemness-related molecules including Nanog,and TIMER online tool was used to analyze the correlations among TβR1,MMP-2,and MMP-9 in esophageal cancer.Results Nanog and MMP-2/MMP-9 proteins were significantly upregulated in ESCC tissues and positively intercorrelated.Their expression levels were closely correlated with infiltration depth and lymph node metastasis of ESCC but not with age,gender,or tumor differentiation.The patients with high expressions of Nanog and MMP-2/MMP-9 had significantly shorter survival time.Bioinformatics analysis showed enrichment of stemness-associated molecules in the TGF-β signaling pathway,and the expressions of MMP-2/MMP-9 and TβR1 were positively correlated.In cultured ESCC cells,Nanog knockdown significantly decreased the expression of TβR1,p-Smad2/3,MMP-2,and MMP-9 and strongly inhibited cell migration.Conclusion The high expressions of Nanog,MMP-2,and MMP-9,which are positively correlated,are closely related with invasion depth,lymph node metastasis,and prognosis of ESCC.Nanog regulates the expressions of MMP-2/MMP-9 proteins through the TGF-β signaling pathway,and its high expression promotes migration of ESCC cells.

Objective To investigate the expression of Nanog and its regulatory relationship with MMP-2/MMP-9 proteins in esophageal squamous cell carcinoma(ESCC).Methods We detected Nanog and MMP-2/MMP-9 protein expressions in 127 ESCC tissues and 82 adjacent normal tissues using immunohistochemistry and explored their correlations with the clinicopathological parameters and prognosis of the patients.GEO database was utilized to analyze the pathways enriched with the stemness-related molecules including Nanog,and TIMER online tool was used to analyze the correlations among TβR1,MMP-2,and MMP-9 in esophageal cancer.Results Nanog and MMP-2/MMP-9 proteins were significantly upregulated in ESCC tissues and positively intercorrelated.Their expression levels were closely correlated with infiltration depth and lymph node metastasis of ESCC but not with age,gender,or tumor differentiation.The patients with high expressions of Nanog and MMP-2/MMP-9 had significantly shorter survival time.Bioinformatics analysis showed enrichment of stemness-associated molecules in the TGF-β signaling pathway,and the expressions of MMP-2/MMP-9 and TβR1 were positively correlated.In cultured ESCC cells,Nanog knockdown significantly decreased the expression of TβR1,p-Smad2/3,MMP-2,and MMP-9 and strongly inhibited cell migration.Conclusion The high expressions of Nanog,MMP-2,and MMP-9,which are positively correlated,are closely related with invasion depth,lymph node metastasis,and prognosis of ESCC.Nanog regulates the expressions of MMP-2/MMP-9 proteins through the TGF-β signaling pathway,and its high expression promotes migration of ESCC cells.