Objective: To explore the association between negative life events and smartphone addiction among middle school students, so as to provide theoretical support and practical guidance for prevention and intervention of smartphone addiction among middle school students. Methods: Using cluster sampling, 8 890 students were selected to survey from 27 junior high schools and 3 senior high schools in a district of Shenzhen in 2022 (baseline) and 2023 (followup). Data were collected through selfresigned questionnaires on basic information, the Smartphone Addiction Scale-Short Version, and the Adolescent Selfrating Life Events Checklist. Mixedeffects models were employed to analyze the association. Results: Compared to 2022, the punishment scores of middle school students in 2023 [1.00 (0.00, 6.00) and 1.00 (0.00, 6.00)] decreased (Z=4.27), while the scores of interpersonal stress, learning stress and adaptation [4.00(0.00, 8.00), 4.00(0.00, 8.00); 4.00(1.00, 8.00), 5.00(2.00, 9.00); 2.00 (0.00, 6.00), 3.00 (0.00, 7.00)] increased (Z=-3.04, -8.36, -6.80) (P<0.01). Mixedeffects models revealed a positive doseresponse relationship between negative life events and smartphone addiction (OR=1.08-1.17, P<0.01). Stepwise regression showed independent positive effects of interpersonal stress (OR=1.05), academic stress (OR=1.03), and adaptation stress (OR=1.11) on smartphone addiction (P<0.01). Subgroup analysis of nonaddicted students in 2022 confirmed persistent associations for academic stress (OR=1.03) and adaptation (OR=1.07) (P<0.01). Conclusion Negative life events exhibit a positive doseresponse relationship with smartphone addiction, particularly interpersonal stress, academic stress, and adaptationrelated events.

Objective: To explore the longitudinal association between only-child status and smartphone addiction among middle school students, so as to provide a basis for establishing family intervention measures for smartphone addiction in middle school students. Methods: In October 2022 and October 2023, a preliminary survey and follow-up were conducted among 8 759 middle and high school students from 30 schools in a district of Shenzhen. A self-designed questionnaire was used to determine whether the students were the only-child, and the Chinese Version of the Smartphone Addiction Scale-Short Version (C-SAS-SV) was utilized to assess the students smartphone addiction status. A multilevel mixed-effects model and subgroup analysis were applied to examine the association between only-child status and smartphone addiction among middle school students. Results: During 2022 to 2023, the prevalence of smartphone addiction in the cohort of middle school students increased from 24.1% to 25.2%. Compared with only-child, non-only child were more likely to be addicted to smartphones (adjusted model: OR =1.2, 95% CI =1.1-1.4) and also scored higher on smartphone addiction (adjusted model: β =0.9, 95% CI =0.2-1.5)( P <0.05). Subgroup analysis further revealed that compared to baseline, non-only child demonstrated an increased prevalence of smartphone addiction (adjusted model: OR = 1.2 , 95% CI =1.0-1.5) and higher addiction scores (adjusted model: β =0.8, 95% CI =0.2-1.5) after one year( P <0.05). Conclusions Non-only child face higher risk of smartphone addiction. Under the current population policy, it is crucial to address smartphone addiction among middle school students who is not only child.

Objective: To explore the potential causal association between adolescent compulsive behaviour and smartphone addiction based on longitudinal data, so as to provide reference for the establishment of adolescent smartphone addiction interventions. Methods: A preliminary survey and follow-up were conducted on 8 907 middle and high school students in a district of Shenzhen in 2022 and 2023, respectively. Compulsive behaviours were measured by using the Mental Health Inventory for Middle School Students-60 Items (MMHI-60), smartphone addiction was assessed by using the Smartphone Addiction Scale-Short Version ( SAS- SV), and the associations between compulsive behaviours and smartphone addiction were analysed by using multilevel mixed-effects models and subgroup analyses. Results: Smartphone addiction detection rates among middle school students were significantly associated with genders, father s education level, mother s education level, study load subgroups, and whether or not they were single-parent families, and there were statistical differences ( χ 2=17.21-175.34, P <0.05). Students with compulsive behaviours were 2.98 times more likely to develop smartphone addiction than those without compulsive behaviours ( OR=2.98, 95%CI=2.77-3.22, P <0.05). Subgroup analysis of middle school students without smartphone addiction in the first year found that compulsive behaviours significantly predicted smartphone addiction ( OR= 1.76 , 95%CI=1.54-2.01, P <0.05). Conclusion There is a potential causal association between obsessive-compulsive behaviours and smartphone addiction in middle school students, and obsessive-compulsive behaviours in middle school students could significantly predicted the occurrence of smartphone addiction.

Objective: To examine the associations of pet ownership and daily outdoor activity duration with depressive symptoms in middle school students, so as to provide evidence for targeted prevention strategies of depressive symptoms in middle school students. Methods: Using a stratified cluster random sampling method, 83 601 middle and high school students from 103 districts and counties in Inner Mongolia Autonomous Region were selected in 2024. A questionnaire survey was conducted to collect demographic data, household pet ownership, outdoor activity duration, and depressive symptoms of the research subjects. The comparison of reporting rates of depressive symptoms among different groups of middle school students was conducted using a χ 2 test. The association between pet ownership and outdoor activity duration and depressive symptoms among middle school students was evaluated using a Logistic regression model, and stratified analysis was conducted among different genders and regions to control for potential confounding factors and evaluate the stability of the association. Results: The prevalence of depressive symptoms among middleschool students in Inner Mongolia was 17.2%. Significant differences in depressive symptom reporting rates were observed across sex, grade, ethnicity, surveillance site, parental education, menarche/spermarche status, boarding status, smoking and alcohol use, daily breakfast consumption, school bullying, continuous 30 minute headphone use in a noisy environment, and often use the Internet ( χ 2=8.07-2 672.57, all P <0.01). Both pet ownership ( OR =0.78, 95% CI =0.75-0.81) and ≥2 h/d of outdoor activity( OR =0.81, 95% CI =0.78-0.84) were inversely associated with depressive symptoms;compared to the without owning pets and < 2 h of outdoor activity daily group, students who both owned pets and engaged in ≥2 h of outdoor activity daily had an even lower risk ( OR =0.83, 95% CI =0.78-0.87)(all P <0.05). Conclusion Pet ownership and increased daily outdoor activity duration may help mitigate depressive symptoms among middle school students.

Objective: To explore the bidirectional associations among body mass index Z scores (BMI Z scores) and weight stigma with depressive symptoms in adolescents, thereby providing evidence for targeted intervention strategies. Methods: A stratified cluster random sampling method was employed to select 18 301 adolescents aged 12-18 years from all 12 prefectures (103 counties) in the Inner Mongolia Autonomous Region, and two waves of longitudinal surveys were conducted in September 2023 (T1) and September 2024 (T2) among the adolescents. Weight stigma was assessed by using a self developed questionnaire, depressive symptom was measured with the Center for Epidemiologic Studies Depression Scale (CES-D), and BMI Z scores were calculated according to the World Health Organization standards. Pearson correlation analysis was used to examine associations among variables, and cross lagged panel models were constructed to investigate the dynamic bidirectional relationships among the three variables. Results: Adolescents BMI Z scores and weight stigma with depressive symptoms all exhibited autoregressive stability across the two time points (autoregressive paths, all P <0.01). Cross lagged model comparisons indicated that the bidirectional path model achieved the best fit ( χ 2=12.65, RMSEA =0.017, CFI =1.000; △ χ 2=193.39, P <0.01), supporting dynamic bidirectional associations among the three variables. After adjusting for gender, age, subjective social status and only child status, T1 BMI Z scores among adolescents positively predicted T2 weight stigma ( β =0.061), and T1 weight stigma positively predicted T2 depressive symptoms ( β =0.608); in the reverse direction, T1 depressive symptoms predicted T2 weight stigma ( β =0.003), and T1 weight stigma predicted T2 BMI Z scores ( β =0.081) (all P <0.01). Conclusions There is a bidirectional cross lagged relationship among adolescents BMI Z scores and weight stigma with depressive symptoms, suggesting that weight stigma may serve as a key psychological variable linking obesity and depressive symptoms. Greater attention should be paid to the potential threat of weight stigma to adolescents mental health, with intervention strategies expanded from a solely physiological focus to encompass psychosocial dimensions.

Objective: To investigate the changing trends for associations of anxiety and depressive symptoms with smartphone addiction among middle school students, so as to provide a scientific basis for preventing smartphone addiction in middle school students. Methods: From 2022 to 2023, a method of combining convenient sampling with cluster sampling was used to select 8 923 middle school students from 27 junior high schools and 3 senior high schools in a district of Shenzhen City between September 2022 (baseline, T1) and September 2023 (follow up, T2). The Smartphone Addiction Scale-Short Version (SAS-SV), Patients Health Questionnaire-9 Item (PHQ-9), and Generalized Anxiety Disorder 7-item Scale (GAD-7) were administered to assess smartphone addiction, anxiety and depressive symptoms. Mixed effects models were used to analyze the association of anxiety and depressive symptoms with smartphone addiction among middle school students. Results: From September 2022 to September 2023, the reported prevalence of smartphone addiction increased from 24.22% to 25.25% ( χ 2=45.71); and smartphone addiction scores [ 24.00 (16.00, 32.00),25.00(16.00, 33.00)], anxiety symptom scores [2.00(0.00, 7.00),3.00(0.00, 7.00)] and depressive symptom scores[3.00(0.00, 8.00),5.00(0.00, 9.00)] all significantly increased ( Z =-17.43, -42.38, -41.57) (all P <0.05). There were statistically significant difference in the distribution of anxiety and depression symptom levels among middle school students in 2022 and 2023 ( χ 2=85.15, 106.85, both P <0.05). After adjusting for covariates such as age, gender and family background, mixed effects models revealed dose response associations of anxiety and depressive symptoms with smartphone addiction among middle school students:mild anxiety symptom( OR =3.22), moderate to severe anxiety symptom ( OR =5.36), mild depressive symptom ( OR =3.32) and moderate to severe depressive symptom ( OR =6.13) were significantly associated with higher risks of smartphone addiction (all P <0.05). Interaction effect analysis found that co existing anxiety and depressive symptoms synergistically increased addiction risk by 5.60 times ( OR =5.60) compared to the asymptomatic group, with 32% of the combined risk attributable to their interaction ( S=1.64, AP =0.32)(both P < 0.05 ). Conclusions Anxiety and depressive symptoms are significantly associated with smartphone addiction, exhibiting a synergistic effect. Attention should be paid to emotional issues and smartphone addiction among middle school students.

Objective: To analyze the prevalence trends of different types of elevated blood pressure and their association with nutritional status among primary and secondary school students in Inner Mongolia from 2019 to 2024, providing references for targeted prevention strategies. Methods: From September 2019 to 2024, a stratified random cluster sampling method was used to select 12 primary and secondary schools from each league city in Inner Mongolia Autonomous Region. A total of 177 108, 137 758, 190 182, 180 084 , 188 056, 180 351 primary and secondary school students (excluding grades one to three of primary school) were included for physical examination. The correlation between their nutritional status and high blood pressure was analyzed based on the basic situation of 129 821 primary and secondary school students who completed a questionnaire survey at the same time in 2024. Statistical analysis was conducted using a Chi-square test and multiple Logistic regression model. Results: From 2019 to 2024, the detection rates of elevated blood pressure were 13.60%, 13.68%, 17.60%, 17.24%, 14.77% and 15.96%, respectively. The rates for isolated systolic hypertension were 4.24%, 5.83%, 7.26%, 7.19%, 6.24% and 6.93%; isolated diastolic hypertension rates were 6.38%, 4.99%, 6.23 %, 6.41%, 5.39% and 5.66%; and combined systolic and diastolic hypertension rates were 2.97%, 2.86%, 4.11%, 3.65%, 3.14 % and 3.36%. Multivariate Logistic regression analysis showed that girls, junior high school, senior high school, overweight, and obesity were positively associated with elevated blood pressure risk ( OR =1.27, 1.25, 1.32, 1.66, 3.07, all P <0.05); conversely, county residence, Mongolian ethnicity, and other ethnicities showed negative associations ( OR =0.90, 0.93, 0.90, all P <0.05). Conclusions Overweight and obesity among children and adolescents are closely related to various types of elevated blood pressure. Prevention strategies should prioritize effectively controlling weight issues among children and adolescents, thereby effectively reducing the incidence of elevated blood pressure.

Objective: To analyze the association between altitudes and nutritional status of children and adolescents, and to explore the moderating effects of dietary behaviors and physical activity, so as to provide a scientific basis for developing lifestyle interventions tailored to local conditions. Methods: From September to November 2023, physical examinations and questionnaire surveys were conducted among children and adolescents aged 7-17 in two autonomous regions, Inner Mongolia and Xizang, with a final sample of 156 511 participants by the stratified cluster random sampling method. Height and weight were measured to calculate body mass index (BMI). Sociodemographic characteristics, dietary behaviors, and physical activity were collected via questionnaires, while the altitude of each participant s school was obtained using Amap. Logistic regression was performed to examine the relationship between altitudes and nutritional status. Interaction terms and stratified analyses were applied to assess the moderating effects of dietary behaviors and physical activity. Restricted cubic spline (RCS) were used for visualization. Results: In 2023, the prevalence of wasting and overweight/obesity among children and adolescents in Xizang were 9.7% and 9.0%, respectively, compared to 2.9% and 22.0% in Inner Mongolia. Logistic regression analysis results showed that for every 1 km increase in altitude, the risk of wasting increased, while the risk of overweight/obesity decreased ( OR =1.43, 0.19, both P <0.05). The results of the stratified analysis showed that compared to those living at altitudes <1 km, children and adolescents with healthy diets showed no significant association between altitudes (1-<2 and 2-<3 km) and wasting ( OR =1.22, 0.75, both P >0.05), whereas significant associations were observed at 3-<4 and ≥4 km altitudes ( OR =2.25, 2.89, both P <0.05). In contrast, unhealthy dietary groups showed statistically significant associations across altitudes ( OR =1.18-4.04, all P <0.05), consistent with RCS results. No moderating effects were observed for physical activity on the altitude wasting association or for dietary behaviors and physical activity combined on the altitude overweight/obesity association ( P interaction =0.63, 0.10, 0.53). Conclusion Healthy dietary behaviors play a critical role in improving the nutritional status of children and adolescents and reducing regional disparities, providing a scientific foundation for public health policy formulation and implementation.

Objective: To understand the current status of malnutrition, depressive symptoms, and their coexistence among middle school students, so as to provide references for exploring the "comorbidity-common cause-common prevention" model for these conditions. Methods: In September 2023, a stratified random cluster sampling method was adopted to select 88 594 students from junior high schools, regular high schools, and vocational high schools in 12 leagues/cities (covering 103 banners/counties) of Inner Mongolia Autonomous Region. Physical examinations were conducted to collect data on malnutrition, and the Center for Epidemiologic Studies Depression (CES-D) Scale was used to assess depressive symptoms. The Chi-square test and multivariate linear stepwise regression analysis were employed to analyze the related factors of malnutrition, depressive symptoms, and their coexistence. Results: In 2023, the detection rates of malnutrition, depressive symptoms, and their coexistence among middle school students in Inner Mongolia were 4.60%, 21.85%, and 0.90%, respectively. There were statistically significant differences in the detection rates of malnutrition, depressive symptoms, and their coexistence among middle school students of different genders, monitoring sites (except for malnutrition), and school stages ( χ 2=4.95-817.39, all P <0.05). The results of the multivariate Logistic regression analysis showed that high school students，drink sugar sweetened beverages ≥1 time per day and those with Internet addiction had higher risk of coexisting malnutrition and depressive symptoms [ OR (95% CI )=1.38 (1.04-1.83), 1.46 (1.20-1.78), 2.28 (1.90-2.74), respectively, all P <0.05 ]. The risk of coexistence was lower among female students, those who ate fresh fruits at least once a day, those who engaged in moderate-to-vigorous physical activity for ≥1 time/day, those who engaged in moderate-to-vigorous physical activity for ≥1 hour/day on ≥5 days/week, those who did not use cough syrup without therapeutic need, those who did not use sedative hypnotic drugs without medical advice, and non-drinking students [ OR (95% CI )=0.84 (0.73-0.98), 0.77 (0.66-0.89), 0.82 (0.68-0.98), 0.66 (0.53- 0.80 ), 0.57 (0.41-0.78), 0.63 (0.53-0.72), respectively, all P <0.05]. Conclusions The occurrence of undernutrition, depressive symptoms, and their coexistence among middle school students in Inner Mongolia can t be ignored. Schools, the government and society should implement a strategy aimed at concurrent prevention of multiple conditions through comprehensive interventions.

Ovulatory dysfunction (OD) is one of the main causes of infertility in women of childbearing age, which not only affects their reproductive ability, but also physical and mental health. Traditional treatment strategies have limited efficacies, and the emergence of biomedicines provides a promising alternative solution via the strategies of combining engineered design with modern advanced technology. This review explores the pathophysiological characteristics and related induction mechanisms of OD, and evaluates the current cutting-edge advances in its treatments. It emphasizes the potentials of biomedicines strategies such as hydrogels, nanoparticles and extracellular vesicles in improving therapeutic precision and efficacy. By mimicking natural physiological processes, and achieving controlled drug release, these advanced drug carriers are expected to address the challenges in ovarian microenvironment reprogramming, tissue repair, and metabolic and immune regulation. Despite the promising progress, there are still challenges in terms of biomedical complexity, differences between animal models and human physiology, and the demand for intelligent drug carriers in the therapy of OD. Future researches are mainly dedicated to developing precise personalized biomedicines in OD therapy through interdisciplinary collaboration, promoting the development of reproductive regenerative medicine.