Objective: To explore the association between mobile phone dependence and constipation of college students in Yunnan Province, and to provide a data reference for improving and preventing constipation in college students. Methods: A questionnaire survey was conducted among 9 960 college students from three universities in Kunming and Dali, Yunnan Province. The Self rating Questionnaire for Adolescent Problematic Mobile Phone Use was used to assess mobile phone dependence symptoms, and the questionnaire was conducted to collect the constipation information of college students. Data were analyzed with SPSS 23.0. Chi square test was used to compare the reporting rates of detection in college students with different demographic characteristics. The association between mobile phone dependence and constipation was analyzed by binary Logistic regression models. Results: The detection rate of mobile phone dependence symptoms was 30.93%, and the reporting rates of constipation was 24.46% of college students in Yunnan Province. After collcted for the demographic variables and other confounding effects, the analysis results showed that:withdrawal symptoms of mobile phone dependence( OR=1.29, 95%CI =1.09-1.54), physical and mental health impacts of mobile phone dependence ( OR=1.25, 95%CI =1.10-1.43) and craving of mobile phone dependence ( OR=1.20, 95%CI =1.06-1.36) were associated with constipation in college students( P <0.01). Conclusion Mobile phone dependence may increase the risk of constipation of college students in Yunnan Province, so health education should be strengthend.

Abstract Early pubertal timing has a significant impact on physical and mental health of children, and is associated with a variety of chronic non communicable disease in adulthood. Risk factors for early pubertal timing are complex, including environmental and genetic factors. As one of the most common environmental pollutants, phthalates can act as endocrine disruptors to affect the body s endocrine system after being exposed to the body. Early life is a disease prone period. Many studies have found that exposure to phthalates can promote adolescent development during perinatal and critical developmental periods. In this paper, the epidemiological studies and related mechanisms of the association between exposure to phthalates and early pubertal timing were summarized and discussed.

Objective: To identify the latent classes of various health risk behaviors among medical students and further analyze the correlation between different classes and depression. Methods: Using the method of convenient sampling, 2 014 medical students were selected from Anhui Medical University in October 2018. Self-designed online questionnaire were used to collect demographic data, health risk behavior (including smoking, drinking, suicide, sleep disorders, mobile phone dependence and lack of exercise) and depressive symptoms. Latent Class Analysis was used to cluster individuals. Logistic regression was provided to further analyze the association between health risk behaviors and depressive symptoms for the groups. Results: The health hazard behaviors of medical students could be divided into three separate classes: substance dependence group (8.4%), mobile phone dependence group (22.4%) and low-risk group (69.2%). The distribution of health risk behaviors of medical students with different gender, major, grade, only child，father s educational level，monthly living expenses, academic achievement and number of friends were statistically significant (χ 2=99.37,19.07,12.05,6.64,14.28,19.35,20.61,26.39,P<0.05). The results of Logistic regression analysis showed that after adjusting for gender, major, grade, only child, father s educational level，monthly living expenses, academic achievement and number of friends, the mobile phone dependence group was positively correlated with depressive symptoms (β=1.75, P<0.01). Conclusion Different ratent classes of health risk behaviors have different correlation with depressive symptoms in groups.It is suggested that school health workers should make individualized intervention plan for different types of health hazard behavior of medical students in the future educational activities, carry out stratified intervention, alleviate the symptoms of depression and promote the mental health of medical students.

Objective To understand the epidemiological characteristics of the cases of COVID-19 epidemic clusters, and explore the influence of family factors and social factors such as group activities on the spread of the disease. Methods The data of cases of COVID-19 epidemic clusters from 19 January, 2020 to 25 February, 2020 were collected from the official platforms of 36 cities in 6 provinces in China. Descriptive statistical methods, χ 2 test and curve fitting were used to analyze the epidemiological characteristics of the clustered cases. Results By 25 February, 2020, the data of 1 052 cases in 366 epidemic clusters were collected. In these clustered cases, 86.9%(914/1 050) occurred in families. Among the 1 046 cases with gender information, 513 were males (49.0%) and 533 were females (51.0%). The cases were mainly young adults between 18 and 59 years old, accounting for 68.5% (711/1 038). In the 366 epidemic clusters , the clusters in which the first confirmed cases with the history of sojourn in Wuhan or Hubei accounted for 47.0%(172/366). From 19 January to 3 February, 2020, the first confirmed cases with Wuhan or Hubei sojourn history accounted for 66.5%. From 4 to 25 February, the first confirmed cases who had Wuhan or Hubei sojourn history accounted for only 18.2%. The median of interval between the first generation case onset and the second generation case onset was 5 (2-8) days. The median of onset- diagnosis interval of the initial cases was 6 (3-9) days, and the median of onset-diagnosis interval of the secondary cases was 5 (3-8) days. Conclusions Epidemic clusters of COVID-19 were common in many cities outside Wuhan and Hubei. Close contact in family was one of the main causes for the spread of household transmission of the virus. After 4 February, the epidemic clusters were mainly caused by the first generation or second generation cases in local areas, and the time for diagnosis became shorter.

Objective: To describe the epidemiological characteristics and clinical manifestations of the 2019 coronavirus disease (COVID-19) in pediatric patients, and to provide data support and decision-making basis for the prevention and control of COVID-19. Methods: Cases of children aged 0-17 years reported by provincial health commissions in Anhui, Shandong, Zhejiang and Henan provinces were collected to analyze their spatial, temporal, and demographic distribution. Results: By 24:00 on February 6, 2020, a total of 107 pediatric patients had been reported in the four provinces, accounting for 3.8% (107/2 808) of the total cases reported in the four provinces during the same period. Anhui, Shandong, Zhejiang and Henan provinces had 25, 25, 28 and 29 cases, respectively. Cases ranged in age from 5 days after birth to 17 years, with a median age of 8 years. Boys accounted for 58.9%. Totally 38 cases had a history of sojourn in Wuhan or Hubei, 63 cases had a history of exposure to confirmed cases, and 6 cases with unknown exposure history. A group of 52 family clustering were found in 107 cases. All cases presented mild symptoms, no serious and no death. Conclusion Children were also susceptible to the COVID-19. Before February 2, the index pediatric cases were mainly the first generation cases, and after February 3, these pediatric cases were mainly the secondary-generation cases and those who had close contact with confirmed cases. The monitoring of children with secondgeneration cases and close contact with COVID-19 cases were valued.

Objective: To describe physical activity (PA) level of college students, and to examine the associations between PA and physical health and depression, so as to provide evidence for health promotion of college students. Methods: During June to July 2018, a cross-sectional survey was conducted among 4 624 college students from 2 universities in Anhui and Jiangxi provinces. The basic information was investigated by the questionnaire. PA was assessed by the International Physical Activity Questionnaire(IPAQ). Physical and mental health were evaluated by the 36-item Short Form Health Survey Questionnaire (SF-36) and the Center for Epidemiologic Studies Depression Scale(CES-D), respectively.Chi-square test was used to examine the differences between physical health and depression among college students with different demographic characteristics. The generalized linear model and binary logistic regression model were used to analyze the relationships between PA and physical health and depression. Results: The proportion of good, medium and poor physical health were 64.5%, 31.6% and 3.9%, respectively. The detection rate of depression was 34.1%. Compared to low PA group, physical health was negatively correlated with medium PA (OR=0.78, 95%CI=0.66-0.91) and high PA(OR=0.46, 95%CI=0.38-0.56). Binary logistic regression results showed that, depression was negatively associated with medium PA (OR=0.69, 95%CI=0.59-0.82) and high PA(OR=0.66, 95%CI=0.55-0.79)(P<0.05). Conclusion There is a significant association between PA and physical health and depression. Further longitudinal studies are needed to clarify the causal relationship between PA and physical and mental health.

Objective: This study aimed to examine the mediating effects of sleep quality in the association between beverages consumption and depressive symptoms in Chinese university students, and to provide a theoretical reference for preventing and reducing depression symptoms. Methods: This school-based cross-sectional survey was carried out among 4 624 university students from 2 universities in Anhui and Jiangxi provinces of China. The patient health questionnaire-9 items (PHQ-9) was used to assess depressive symptoms. The Pittsburgh sleep quality index（PSQI） was used to assess sleep quality, and a self-reported dietary frequency questionnaire was used to measure beverages consumption. The quantile regression model was used to association analysis, and the latent variable mediation model was used to analyze the mediation effect. Results: The positive rates of mild, moderate, moderate to severe and severe depression in 4 624 university students were 31.4%, 7.5%, 4.1% and 2.0%, respectively. There was a significant association between the beverages consumption score, the PSQI score, and the PHQ-9 score( P <0.01). The higher the quantile of the beverage consumption and PSQI score, the greater the regression coefficient ( β ), and a significant dose-response relationship was observed( P <0.01). In the latent variable mediation model of beverages consumption associated with depressive symptoms in Chinese university students, the mediating effect value of sleep quality was 0.12, and the ratio of mediating effect to total effect was 71.3%. Conclusion Our study demonstrates that poor sleep quality partially mediates the association between beverages consumption and depressive symptoms in Chinese university students.

Objective: To explore the association between interaction effects of dietary behaviors and caregivers s type on overweight or obesity among left-behind children, and to provide a reference for overweight or obesity prevention among the left-behind children. Methods: From October to December 2018, 877 left-behind children aged 7-18 years were randomly selected from a stratified cluster in county, Shangrao City, Jiangxi Province.Type of caregives, dietary behavior, health status were collected from questionnaires, height, weight were examined. Results: The detection rate of overweight and obesity in left-behind children was 21.7%(190/877), and the rate of overweight and obese left-behind children with other foster parents was 29.8%(158/530), higher than the rate of 16.2%(32/198). The detection rate of overweight and obesity of left-behind children who consumed high level of western fast food was 59.0%(59/100). There were significant differences in rate of overweight and obesity by type of caregiver and western food consumption. Regression analysis showed that the detection rate of overweight and obesity of left-behind children who often ate western fast food was 5.70 times(95%CI=3.62-8.99) high than that of those who seldom ate western fast food. Interaction analysis showed that the interaction(synergistic effect) of the type of adopter × whether the adopter often ate western fast food(father or mother × yes) presents a positive multiplying interaction(synergistic effect). Left-behind children under paternal or maternal care together with high western fast food consumption greatly increased the risk of overweight and obesity(OR=6.94, 95%CI=2.76-17.44). Conclusion Frequent consumption of western fast food together with one parent stay at home is associated with overweight and obesity of left-behind children. These two factors have a synergistic effect, which greatly increases the risk of overweight and obesity of left-behind children. In other words, their interaction is a major risk factor.

Objective: To explore the association between co-consumption of takeaway fast foods and sodas with depressive symptoms among Chinese adolescents, and to provide a reference for reducing the occurence of depression among adolescents. Methods: A multi-center population-based survey was conducted in 32 schools in 4 provinces across China. A total of 14 500 adolescents completed eligible questionnaires. Depressive symptoms were assessed by using Children’s Depression Inventory(CDI), while consumption of takeaway fast foods and sodas was collected using the semi-quantitative Food Frequency Questionnaire(FFQ). Results: 27.26%(3 952/14 500) of adolescents were reported of depressive symptoms. The low, middle, and high-frequency consumption of takeaway fast foods (a OR=1.12, 1.73, 1.56, P<0.05) and sodas (a OR=1.64, 2.17, 3.54, P<0.01) were associated with depressive symptoms, and dose-response relationships were observed in all association(P<0.01). Meanwhile, positive additive interactions were observed in the association(a OR=2.46, P<0.01). The relative excess risk, attribution ratio and the interaction index of synergy was 0.45(0.12-0.77), 0.18(0.06-0.30) and 1.44(1.10-1.89), respectively. Conclusion Co-consumption of takeaway fast foods and sodas significantly associates with depressive symptoms by synergistic effect among Chinese adolescents.

Objective: To explore the correlation of health literacy and mobile phone use dependence with psychopathological symptoms in middle school students. Methods: 22 628 middle school students in Shenyang, Bengbu, Xinxiang, Ulanqab, Chongqing and Yangjiang were enrolled by multistage cluster sampling method from November 2015 to January 2016. Chinese Adolescent Interactive Health Literacy Questionnaire (CAIHLQ), Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) and Multidimensional Sub-health Questionnaire of Adolescents (MSQA) were applied to acquire basic characteristics, health literacy, mobile phone use dependence and psychopathological symptoms of subjects. Subjects were classified into three groups, low level (<P₂₅), medium level (P₂₅-P₇₅) and high level (>P₇₅), according to the percentile of the questionnaire score. Multivariate logistic regression model was used to analyze the correlation of health literacy, mobile phone with psychopathological symptoms. Results: The students were (15.4±1.8) years old with 10 990 boys (48.6%). The score of health literacy of students were (104.1±18.7) points. The rate of mobile phone use dependence was 25.4% (5 752/22 628) and the rate of psychopathological symptoms was 29.1% (6 581/22 628). Compared with high health literacy level, medium and low health literacy levels were related to psychopathological symptoms, with OR (95%CI) about 2.30 (2.10-2.52) and 5.40 (4.89-5.97), respectively. Compared with mobile phone use independence, mobile phone use dependence was related to psychopathological symptoms, with OR (95%CI) about 3.60(3.37-3.85). The highest rate of psychopathological symptoms occurred in students with mobile phone use dependence and low health literacy level [68.0% (1 345/1 977)], with OR (95%CI) about 19.59 (17.07-22.48). Conclusion Health literacy and mobile phone use dependence are related factors of psychopathological symptoms in middle school students.