Objective: To explore the mediating effect and gender difference of mobile phone use in the association between different types of childhood abuse experiences and sleep quality of medical students, so as to provide reference for promoting sleep quality of medical students. Methods: A longitudinal study design method was used to select freshmen and sophomores in two medical colleges in Anhui Province from November to December 2019, follow up data were collected from May to June 2020, and a total of 6 879 students were included in this study. Spearman correlation was used to analyze the association between baseline childhood abuse experiences, baseline mobile phone use and follow up sleep quality. Bootstrap program and Process software were applied to test the mediating effect of mobile phone use in the relationship between childhood abuse and sleep quality. Results: Childhood abuse experiences were positively correlated with mobile phone use and sleep quality score ( r = 0.27 , 0.24, P <0.01), and mobile phone use was positively correlated with sleep quality score ( r =0.31, P <0.01). In the total sample, after adjusting for confounding factors, mobile phone use played a partial mediating role in childhood abuse experiences (including emotional abuse, physical abuse, sexual abuse) and sleep quality, and the mediating effect was 18.08% (18.12%, 17.15%, 24.09%). The mediating effect of mobile phone use on the relationship between childhood emotional abuse, sexual abuse, childhood abuse and sleep quality in girls(18.32%, 28.05%, 18.24%) was higher than in boys(17.81%, 18.94%, 17.63%). Conclusion Mobile phone use has a mediating effect on the relationship between childhood abuse and sleep quality, controlling mobile phone overuse may contribute to improving the sleep quality for those who have experienced childhood abuse.

Objective: To develop the Adolescent Mental Health Literacy Assessment Questionnaire (AMHLAQ), and to evaluate its reliability and validity among undergraduates. Methods: On the basis of the definition of mental health literacy (MHL) and the Knowledge, Attitudes and Practices (KAP) theory, this study constructed a total of 36 items consisting of four dimensions, and scores were measured according to a five point Likert type scale. Using a cluster sampling method, a questionnaire survey was conducted among 3 826 freshmen and sophomore students from two medical schools in Anhui Province. The items were screened by performing t tests, Pearson s correlation coefficient analysis and factor analysis. The reliability and validity of the questionnaire were evaluated using indicators including homogeneity reliability, the split half reliability coefficient, and construct validity. Results: Factor analysis revealed that the AMHLAQ consisted of 22 questions grouped into four domains. The variance cumulative contribution rate was 62.213%. The reliability result showed that the Cronbach s alpha coefficient of the total questionnaire was 0.897, the split half reliability was 0.800, the Cronbach s coefficient of each dimension was 0.796 to 0.885, the split half reliability of each dimension was 0.725 to 0.846, and the indicators had a high level of reliability. Confirmatory factor analysis showed that the model fit was good ( χ 2/df =19.319, P <0.01; RMSEA=0.069). Conclusion AMHLAQ is consistent with the evaluation standard of psychometrics, has good reliability and validity, and can be used to estimate the level of MHL among undergraduates.

Objective: To explore the association between middle school students health literacy and bully victimization and associated sex difference, and to provide guidance for bully prevention in adolescents. Methods: During November 2017 to January 2018, 18 900 junior and senior high school students were enrolled from Hefei of Anhui Province, Shenyang of Liaoning Province, Yangjiang of Guangdong Province and Chongqing by multistage cluster sampling. A self rated questionnaires were used to collect demographic information, health literacy, and bully victimization. Group differences by different characteristics and the association between health literacy and bully victimization were analyzed. Results: The detection rates of campus and cyber bullying victimization were 15.8% (2 992/18 900) and 9.1% (1 723/18 900). Boys, junior high school students, students with poor family financial status and few close friends had a detection rate of 28.0%, 18.8%, 23.3%, and 33.6% of school bullying, which are higher than those of the control group ( χ 2=225.64, 148.07, 141.13, 143.49, P <0.01); boys, students with poor household income and few close friends, the detection rates of cyber bullying were 10.9%, 14.4%, and 20.1%, respectively, are higher than the control group ( χ 2=62.96, 112.82, 88.49, P <0.01). Multivariate Logistic regression analysis indicated that students with low overall and dimensions scores of health literacy were more likely to suffer from campus and cyber bullying, except for the dimension of physical activity. In addition, at all levels of health literacy, males are more likely to be bullied than females ( P <0.05). Conclusion Health literacy of middle school students is related to bully victimization, which is sex specific. Intervention programs of bullying should focus on health literacy enhancement.

Objective: To explore the association between health literacy and drinking behaviors among middle school students in six provinces of China, and to provide scientific basis for the prevention and intervention of drinking behaviors. Methods: From November 2015 to January 2016, 22 628 students were enrolled from Ulanqab, Shenyang, Xinxiang, Bengbu, Chongqing and Yangjiang by multistage stratified cluster sampling method. And a questionnaire survey was conducted among them to collect demographic information, health literacy and drinking behaviors. Rates on drinking behaviors were compared in students with specific characteristics. Multiple Logistic regression analyses were conducted to examine the association between health literacy and drinking behaviors. Results: The proportion of ever drinking, current drinking, binge drinking, drunkenness was 60.0%(13 580), 16.8%(3 799), 5.9%(1 344) and 9.9%(2 250), respectively. After adjusting for gender, grade, family address, siblings, accommodation type, parental educational level, and self reported family income, compared to the high level health literacy, the low level health literacy was significantly associated with ever drinking (OR=1.76, 95%CI=1.62-1.91), current drinking(OR=1.37, 95%CI=1.23-1.52), binge drinking (OR=1.39, 95%CI=1.18-1.63), and drunkenness(OR=1.68, 95%CI=1.47-1.92), respectively(P<0.01). Conclusion Health literacy of middle school students was related to drinking behaviors. The occurrence of health risk behaviors such as drinking can be prevented and reduced by improving students health literacy level.

Objective:To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen.Methods:From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin′an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ 2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results:The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [ OR (95% CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [ OR (95% CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [ OR (95% CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion:The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

Objective:To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen.Methods:From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin′an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ 2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results:The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [ OR (95% CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [ OR (95% CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [ OR (95% CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion:The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

Objective:To examine whether sleep status and social jet lag are related to the mental health behaviors in children and adolescents, providing a reference for preventing and improving children and adolescents' mental health behaviors.Methods:A large cross-section was conducted in Baoan District, Shenzhen, from April to May 2019. A total of 30 188 adolescents and children in grades 1-12 in 14 schools were included. The growth trajectory and health index questionnaire of primary and secondary school students were designed to evaluate the sleep status. Mental health behavior problems among students were accessed using the parents' and students' versions of the Strengths and Difficulties Questionnaire. After controlling for confounding factors of demographic variables, including gender, age, parental education level, academic performance, learning burden, and noise impact, a multivariate logistic regression model was used for statistical analyses.Results:The sleep duration of four grades students were 90.4％,90.1％, 98.2％, and 98.4％, respectively. 19.9％ did not have a post-lunch nap. 19.6％ had a wake-up delay of more than or equal to 2 h weekend morning. 35.1％ had an inconsistent bedtime and 15.5％ had an inconsistent awakening time. The multivariate logistic regression model showed that compared with 8-9 h, the sleep duration of elementary school juniors at night less than or equal to 7 h, 7-8 h increased the risk of psychological behavior problems. The sleep time more than 9 h was negatively correlated with psychological behavior problems. The sleep duration of elementary school seniors less than or equal to 7 h increased the risk of psychological behavior problems. The sleep duration of middle school and high school students less than or equal to 6 h increased psychological behavior problems. The ORs (95％ CI) appeared as 2.53(1.85-3.47), 2.41(1.11-5.25), respectively. The ones with a sleep time more than 9 h also increased the risk, and ORs (95％ CI) appeared as 2.37(1.40-4.01), 5.38 (1.79-16.1), respectively. Both the absence of post-lunch nap and the nap time less than 0.5 h were risk factors for psychological behavior problems in primary and middle school students. The nap time over 1-2 h was also a risk factor for high school students' psychological behavior problems. Waking up at irregular times in the morning, going to bed at varying times in the evening, and delaying getting up for more than or equal to 2 h on weekends were all risk factors for psychological and behavioral problems among primary and middle school students. The ORs (95％ CI) of psychological behavior problems of elementary school juniors and seniors, middle school and high school students were 2.07 (1.45-2.97), 1.57 (1.09-2.26), 2.66 (2.06-3.44), 2.48 (1.96-3.15), respectively. Conclusions:Sleep duration, no post-lunch sleep, and daily intraindividual variability of sleep is positively associated with poor mental health. Additionally, social jet lag is associated with mental health problems in students. It is noted that delaying sleep within half an hour on the weekends of elementary school juniors is significantly associated with an increase in bad mental behavior.

Objective:To examine treatment outcomes of breast phyllodes tumors and the prognosis factors of local recurrence.Methods:This retrospective cohort study included 276 patients who underwent surgical resection at Breast Center, Peking University People′s Hospital from January 2011 to December 2019. Tumor subtype and histopathological features were determined from pathology reports, and the deadline of follow-up was September 30 th, 2020. All 276 patients underwent open surgery, including 17 patients of mastectomy, and 259 patients of lumpectomy. The enrolled patients were all female, with age of (41.5±11.3) years (rang: 11 to 76 years), and tumor diameter of 35(28) mm ( M( Q R)). The Kaplan-Meier method and Log-rank test were used for survival analysis. The multivariate analysis was implemented using the Cox proportional hazard model. Results:According the pathologic test, there were 191 patients of benign phyllodes tumor, 67 patients of borderline tumor and 18 patients of malignant tumor. There were 249 patients with a follow-up of more than 6 months, and 14.1% (35/249) had local recurrence. The time-to-recurrence was (28.6±22.2) months (range: 2 to 96 months), (29.1±18.1) months (range: 2 to 80 months), (32.1±30.1) months (range: 5 to 96 months) and (12.0±6.9) months (range: 8 to 20 months) for benign, borderline and malignant phyllodes tumors. Tumor diameter (≥100 mm vs.<50 mm, HR=3.968, 95%CI: 1.550 to 10.158, P=0.004) and malignant heterologous element (yes vs. no, HR=26.933, 95%CI: 3.105 to 233.600, P=0.003) were prognosis factors of local recurrence. One death from malignant phyllodes occurred after distant metastasis. The 3-year disease-free survival rates of benign, borderline and malignant phyllodes tumor were 88.2%, 81.7% and 81.4% ( P=0.300). Conclusion:Phyllodes tumors have a considerable local recurrence rate, which may be associated with tumor diameter and malignant heterologous element.

Objective:To examine treatment outcomes of breast phyllodes tumors and the prognosis factors of local recurrence.Methods:This retrospective cohort study included 276 patients who underwent surgical resection at Breast Center, Peking University People′s Hospital from January 2011 to December 2019. Tumor subtype and histopathological features were determined from pathology reports, and the deadline of follow-up was September 30 th, 2020. All 276 patients underwent open surgery, including 17 patients of mastectomy, and 259 patients of lumpectomy. The enrolled patients were all female, with age of (41.5±11.3) years (rang: 11 to 76 years), and tumor diameter of 35(28) mm ( M( Q R)). The Kaplan-Meier method and Log-rank test were used for survival analysis. The multivariate analysis was implemented using the Cox proportional hazard model. Results:According the pathologic test, there were 191 patients of benign phyllodes tumor, 67 patients of borderline tumor and 18 patients of malignant tumor. There were 249 patients with a follow-up of more than 6 months, and 14.1% (35/249) had local recurrence. The time-to-recurrence was (28.6±22.2) months (range: 2 to 96 months), (29.1±18.1) months (range: 2 to 80 months), (32.1±30.1) months (range: 5 to 96 months) and (12.0±6.9) months (range: 8 to 20 months) for benign, borderline and malignant phyllodes tumors. Tumor diameter (≥100 mm vs.<50 mm, HR=3.968, 95%CI: 1.550 to 10.158, P=0.004) and malignant heterologous element (yes vs. no, HR=26.933, 95%CI: 3.105 to 233.600, P=0.003) were prognosis factors of local recurrence. One death from malignant phyllodes occurred after distant metastasis. The 3-year disease-free survival rates of benign, borderline and malignant phyllodes tumor were 88.2%, 81.7% and 81.4% ( P=0.300). Conclusion:Phyllodes tumors have a considerable local recurrence rate, which may be associated with tumor diameter and malignant heterologous element.

Objective: The aim of this paper is to understand the associations between childhood abuse experience,parent-child relationship and non-suicidal self-injury (NSSI) in middle school students. Methods: Stratified cluster sampling method was used to select 14 500 middle school students from Shenzhen,Zhengzhou,Nanchang and Guiyang as participants. Questionnaire survey was conducted to collect information on childhood abuse exposure,parent-child relationship and NSSI. Results: The prevalence of NSSI was 14.81%,while it was higher among male students (15.95%) than female students (13.64%) (χ2=15.29,P<0.01). A multivariate Logistic regression models showed that the moderate and high level of childhood abuse (OR=2.23,3.27) and the low level of parents-child relationship (OR=1.80,1.36) were associated with high NSSI detection rate among middle school students (P<0.01). In each group of childhood abuse,low level of father-child relationship was associated with high NSSI detection rate among middle school students (OR=1.36,1.34,1.56,P<0.05). In the group with high level of childhood abuse experience,low level of mother-child relationship was associated with high NSSI detection rate (OR=1.20,P<0.05). Among male students,those with high level of childhood abuse experience,low level of parentchild relationship were associated with high NSSI detection rate (OR=1.46,1.35,P<0.01); regardless of the level of childhood abuse experience,low level of father-daughter relationship was associated with NSSI detection rate (OR=1.64,1.54,1.68,P<0.01) among females. Conclusion Childhood abuse experience and poor parent-child relationship are associated with NSSI in middle school students, with distinct gender difference. Prevention of childhood abuse and the improvement of parent-child relationship are beneficial to the prevention and control of NSSI.