Abstract The health of children and adolescents is not only related to the growth and wellbeing of individuals, but also to the construction and development of countries. This study reviewed policies that were issued by the central government since the founding of New China which focused on the prevention and treatment of common diseases among school-age children and adolescents. The results revealed that, since the founding of New China, policies for the prevention and control of common diseases among school-age children and adolescents increased in number, and they began to focus on specific rather than general health problems. A gradual emphasis was placed on the specific implementation of prevention and control measures, rather than on guiding principles. Increasingly more attention has been paid to the prevention and treatment of common diseases among school-age children and adolescents.

Objective: To analyze physical fitness and health status and gender differences of middle school students among 5 minorities (Mongolian, Hui, Uyghur, Zhuang and Korean), and to provide the theoretical basis for the strategy formulation. Methods: The present data came from 3 waves of Chinese National Survey on Students Constitution and Health (2010, 2014, and 2019). According to National Standards for Students Physical Health (2014 Revision), excellent, and excellent good physical fitness and health status were defined. Cochran Armitage test was used to examine the trends of physical fitness and health status. Chi square test and Logistic regression were used to analyze the difference of physical fitness and health status by sex and survey year. Results: From 2010 to 2019, the excellent physical fitness and health status rate of Mongolian, Hui, Uyghur, Zhuang and Korean students increased from 1.8%, 0.7%, 0.3%, 0.5% and 1.3% to 4.3%, 2.8%, 1.2%, 1.3% and 3.5%, respectively. The excellent good physical fitness and health status rate of Mongolian, Hui, Uyghur and Zhuang students increased from 12.9%, 8.0%, 7.2 % and 8.4% to 24.7%, 20.1%, 12.6% and 19.8%( Z =6.15，6.71，4.12，3.06，5.26；11.88，13.42，6.70，11.08， P <0.05), respectively. In 2019, students aged 13 to 15 years showed higher proportion of excellent/excellent good physical fitness and health status than that of students aged 16 to 18. Boys were more likely to be in excellent/excellent good physical fitness and health status than girls from 2010 to 2019. The sex difference in excellent/excellent good physical fitness and health status narrowed during 2010 and 2019. Conclusion Physical fitness and health status of minority students improved while sex difference narrowed during last decade, but there is still a long way to reach the goal proposed by China. Targeted intervention should be proposed to promote physical fitness and health status in accordance with the developmental characteristics, especially for girls and students aged 16 to 18 years.

Objective: To analyze the association between the occurrence of menarche and the exposure to artificial light at night (ALAN) in female Han nationality girls aged 9-18 in China, so as to provide a reference for the research on the disturbance mechanism of ALAN on puberty, as well as provide a scientific evidence for controlling ALAN and making public sanitary policy. Methods: A total of 74 483 Han girls aged 9-18 with complete records of menarche, height, and weight were included in the 2014 Chinese National Surveys on Students Constitution and Health. Pearson correlation was used to explore the correlation between the incidence of menarche and the exposure to artificial light at night in 11-year-old Han girls, and the third quantiles of the area covered by outdoor night lights (0.16, 0.60) and the third quantiles of the average night light intensity [0.97, 5.91 nw/(sr ·cm) 2] were used respectively to divide the study subjects into 3 groups, and the multifactor Logistic regression model was used to analyze the effect of artificial light at night exposure on menarche. Results: In 2014, the median age of menarche of Chinese Han girls was 12.18 years old, and the incidence of menarche in the 11-year-old group was 26.31%. After controlling for body mass index, local population and the logarithmic values of per capita GDP, the incidence of menarche of 11-year-old Han girls was positively correlated with the local outdoor average night light coverage area ratio and the night average light intensity logarithmic adjustment value( r =0.29, 0.30, P <0.05).The higher the local outdoor night light coverage area ratio ( OR =1.28, 1.52) and the average night light intensity ( OR =1.47, 1.58), the higher the incidence of menarche in 11-year-old Han girls( P <0.05). Conclusion There is a positive correlation between artificial light at night exposure and the menarche rate of 11-year-old Han girls. Research on artificial light at night exposure may provide scientific evidence on puberty onset and its effects on population health.

Objective To investigate the risk factors for non-curative resection after endoscopic submucosal dissection ( ESD ) for early esophageal cancer and high-grade intraepithelial neoplasia .Methods The clinicopathological data of 427 cases of early esophageal cancer and high-grade intraepithelial neoplasia who underwent ESD was performed from January 2013 to December 2016 in the Department of Gastroenterology , First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed .According to the results of postoperative pathology and immunohistochemistry ,339 patients were defined as curative resection group and 88 patients were defined as non-curative resection group .Chi-square test , univariate analysis and multivariate logistic regression analysis were used for statistical analysis .Results A total of 427 patients were enrolled in this study, with an average age of (63.2 ±7.7) years, including 96 cases of early esophageal cancer and 331 cases of high-grade intraepithelial neoplasia .The enbloc resection rate of ESD was 94.8％(405/427), 88 of them were non-curative resected, and the non-curative resection rate was 20.6％.Univariate analysis showed that early esophageal cancer (odds ratio (OR)=3.682, 95％confidence interval (CI) 2.216 to 6.118, P<0.01), submucosal infiltration (OR=10.220, 95％CI 4.861 to 21.481, P<0.01), ESD indications (OR=6.005, 95％CI 3.545 to 10.172, P<0.01) and lifting sign after injecting at the base of lesions (OR=2.508, 95％CI 1.005 to 6.255, P=0.042) were statistically significant between non-curative resection group and curative resection group . Multivariate unconditional logistic regression analysis revealed that submucosal infiltration (OR =4.329, 95％CI 1.758 to 10.661,P =0.001), not absolute indications of ESD (OR =6.484, 95％CI 2.205 to 19.068, P=0.001) and negative lifting sign (OR=3.182, 95％CI 1.171 to 8.651, P=0.023) were independent risk factors for non-curative resection.Conclusions Patients with early esophageal cancer , submucosal infiltration , not absolute indications for ESD and negative lifting signs are prone to non-curative resection .Moreover , submucosal infiltration , not absolute indications for ESD , and negative lifting signs are the independent risk factors for non-curative resection .

Objective: To analyze the prevalence of comorbidity of spinal curvature abnormality and malnutrition among primary and secondary school students aged 10-18 years in Tianjin in 2023, so as to provide scientific basis for the combined prevention of common diseases and multiple diseases among students and the construction of school health system. Methods: In September to October 2023, 31 884 primary and secondary school students aged 10 to 18 years in Tianjin were selected using stratified cluster random sampling. Abnormal spinal curvature in children and adolescents was assessed by Sereening of Spinal Curvature Abnormality of Children and Adolescents, while stunting, wasting, overweight, and obesity were determined according to the Screening for Malnutrition among Schoolage Children and Adolescents and Screening for Overweight and Obesity among Schoolage Children and Adolescents. The χ2 test was used to compare betweengroup differences in coprevalence, and multiple Logistic regression models were used to analyze the risk of different comorbidity types in different clusters. Results: The coprevalence of spinal curvature abnormality and malnutrition among primary and secondary school students in Tianjin was 1.6%, which was higher for girls than boys (1.8%, 1.4%), higher (2.5%) for senior high schools than for junior high schools and elementary schools (2.0%, 0.5%), and higher in rural than in urban areas (2.1%, 1.1%) (χ2=9.45, 141.92, 46.94, P<0.05). Multiple Logistic regression models showed that junior high school girls had a higher risk of incorrect posture comorbid with stunting and wasting (OR=4.52, 95%CI=1.84-11.06) and incorrect posture comorbid with overweight and obesity (OR=2.67, 95%CI=1.74-4.10) than boys, and that scoliosis/sagittal spinal abnormality comorbid with stunting and wasting (OR=0.10, 95%CI=0.02-0.44) risk was lower than that of boys, senior high school girls had a lower risk of scoliosis/sagittal spinal abnormality comorbid with overweight and obesity (OR=0.27, 95%CI=0.11-0.66) (P<0.05). Conclusions The coprevalence of spinal curvature abnormality and malnutrition is specific among primary and secondary school students in Tianjin, and the comorbidity type varies by gender and education stage. There is a need to increase prevention and control of spinal curvature abnormalities in school health working, intensive screening of key populations, and timely intervention.

Objective: To construct core information about physical activities of Chinese students aged 7-18 years, so as to provide a reference for impoving the level of adolescents physical activities. Methods: Canadian 24 Hour Movement Guidelines for Children and Youth was used as a framework, the preliminary core recommendations on physical activity for Chinese students aged 7-18 years were developed based on qualitative research. Recommendations covered three scales, including physical activity, sedentary behaviour and sleep. Physical activity included four subscales of frequency, intensity, duration and type, while sedentary behaviour and sleep only included one subscale. Three rounds of consultation were conducted using Delphi method. In the second round of consultation, the results of 2014 Chinese National Surveys on Students Constitution and Health were presented to experts for reference. In the third round of consultation, experts need to rank the importance of seven items of physical fitness under the physical activity type subscale by age group through analytic hierarchy process. Results: Totally 25, 25, and 18 experts were consulted in three rounds respectively. The questionnaire response rates in 3 rounds were 100.0%, 100.0%, and 94.4%, respectively. The authority coefficients were 0.92, 0.93, and 0.91. The harmony coefficients were 0.63( χ 2=237.10, P <0.01), 0.63( χ 2= 242.60 , P <0.01), and 0.76( χ 2=97.05, P <0.01). It was recommended that students aged 7 to 18 years in China should do moderate to vigorous physical activity for a cumulative total of at least 60 minutes per day, and most of the 60 minutes or more per day should be either moderate or vigorous intensity aerobic physical activity. Of the daily physical activity, students should conduct vigorous intensity aerobic physical activity, muscle strengthening and bone strengthening physical activity on at least 3 days a week. At least 2 hours of daytime outdoor activity was recommended for primary school students and 1 hour for secondary school students. 7-12 year old students should do more physical activities that enhance flexibility, coordination and agility, while 13-18 year old students should do more physical activities that enhance strength, endurance and speed. Sedentary behaviour included one subscale, where students should reduce sedentary behaviour, break up long periods of sitting as often as possible, and limit recreational screen time and online study time. Sleep included one subscale of duration.Students should get sufficient and uninterrupted sleep per night. Conclusion The development of core recommendations on physical activity for Chinese students aged 7 to 18 might help improve physical activity levels and promote health of children and adolescents.

Objective: To analyze the hotspots, frontiers, and future research trends related to puberty development among children and adolescents from 2013 to 2022, and to provide a reference for subsequent research related to puberty development. Methods: Data related to puberty development from 2013 to 2022 were retrieved from the Web of Science core collection with the search formula "puberty timing (title) OR puberty development (title) OR pubertal timing (title) OR pubertal development (title) OR puberty timing (abstract) OR puberty development (abstract) OR pubertal timing (abstract) OR pubertal development (abstract)". The CiteSpace was used for visual analysis. Results: A total of 6 684 publications were obtained and an upward trend could be seen in the number of publications in the field of puberty development in the last 10 years. Researchers with a high number of publications were Juul Anders, Brix Nis, and Ernst Andreas, in addition, the United States had the highest number of publications ( 2 125 ) and the highest betweenness centrality (0.23) in this field. In the last decade, research hotspots had focused on the timing of pubertal initiation, biological mechanisms of pubertal development, and sex differences in pubertal development. Research on environmental endocrine disruptors and the mechanisms of pubertal development were at the forefront of research and future research trends. Conclusion Scholars can refer to the research hotspots and research trends in this field and focus on the issues related to environmental endocrine disruptors and pubertal development mechanisms.

Objective:To analyze the regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014.Methods:The Chinese Han students aged 7 to 18 years with complete basic information and height data from 30 mainland provinces (excluding Hong Kong, Macao, Taiwan and Tibet in China) were extracted as participants from 6 successive cross-sectional surveys of the Chinese National Survey on Student′s Constitution and Health (CNSSCH). After excluding extreme and illogical cases, a total of 1 495 182 students were included in the analysis. The data of gross domestic product (GDP) per capita of each province at each survey year were collected from the website of National Bureau of statistics of China. Mann-Kendall trend test was used to analyze the trend of mean height across years. Weighted linear regression model was used to analyze the association between mean height of students aged 7 to18 years and GDP per capita at provincial level. Height difference, height ratio, slope index of inequality (SII) and relative index of inequality (RII) were used to measure the height inequality by gender and age groups.Results:The mean height of Chinese Han students aged 7 to 18 years increased from 144.9 cm in 1985 to 151.8 cm in 2014 ( P<0.05). The height difference between urban and rural students in all age groups was reducing ( P<0.05). The height difference between urban and rural boys aged 13 to 15 years decreased from 5.3 cm in 1985 to 2.5 cm in 2014, and the difference between urban and rural girls aged 7 to 12 years decreased from 4.6 cm in 1985 to 2.4 cm in 2014. The mean height of students aged 7 to 18 years was positively associated with GDP per capita in all survey years for both genders ( P<0.001). Taking Shanghai and Guizhou as the representatives of economically developed and underdeveloped provinces, from 1985 to 2014, the height differences between two provinces were 6.8-9.2 cm, 8.0-12.4 cm and 6.3-8.8 cm for boys aged 7 to 12 years, 13 to 15 years and 16 to 18 years, respectively, and the height ratios were stable at 1.05-1.07, 1.05-1.08 and 1.04-1.05 respectively. From 1985 to 2014, the SII of mean height for boys in three age groups were 4.4-6.2, 4.9-6.7 and 2.5-4.7, respectively. The RII of mean height of boys in three age groups were 1.03-1.05, 1.03-1.04 and 1.01-1.03, respectively. In the same period, the SII of mean height for girls in three age groups were 4.2-6.2, 2.8-4.5 and 2.5-3.9, and the RII were 1.03-1.05, 1.02-1.03 and 1.02, respectively. Conclusion:From 1985 to 2014, the urban-rural inequality of height development among Chinese Han students aged 7 to 18 years was narrowing, but the socio-economic inequality of height persisted and remained at a relatively stable level.

Objective:To describe the current distribution of daily physical activity time among ele-mentary and junior high school students in Beijing,and to analyze the influencing factors and pathways at the individual,family,school and community levels.Methods:Data were drawn upon from a cross-sectional investigation in Beijing in 2023,and a total of 3 157 elementary and junior high school students were included in the final analysis.Questionnaire was used to collect data on basic characteristics,over-all and in-school physical activity time per day,the number of sports mastered,perceived physical activi-ty benefits and barriers scales,perceived family,school,and community physical activity supportive en-vironment scales.Log-binomial regression model was used to analyze the associations between physical activity time and influencing factors,and structural equation modeling was used for the path analysis of the influencing factors.Results:The reported rates of ≥ 2 hours of overall physical activity per day and≥1 hour of physical activity in school per day among elementary and junior high school students in Beijing in 2023 were 33.1％and 64.8％,respectively.The associations between the number of sports mastered by students and the reported rate of ≥2 hours of overall physical activity per day showed a typical dose-response relationship(P-trend＜0.001).The perceived physical activity benefits-to-barriers ratio(PR=1.24,95％CI:1.20-1.28),scores of perceived family,school,and community physical acti-vity supportive environment scales were all positively associated with the reported rate of≥2 hours of overall physical activity per day(PR=1.51,95％CI:1.38-1.66;PR=1.50,95％CI:1.37-1.64;PR=1.21,95％CI:1.16-1.27).The structural equation modeling showed that the number of sports mastered by the students(β=0.11,P＜0.001),perceived physical activity benefits-to-barriers ratios(β=0.15,P＜0.001),and scores of supportive environment scales consisting of family,school,and community(β=0.13,P＜0.001)were associated with the reported rates of ≥2 hours of overall physi-cal activity per day directly.In addition,the scores of supportive environment scales could indirectly in-fluence the reported rates of ≥2 hours of overall physical activity per day by influencing the number of sports mastered by the students(β=0.21,P＜0.001)and the perceived physical activity benefits-to-barriers ratio(β=0.56,P＜0.001),while the number of sports mastered by the students could indi-rectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the per-ceived physical activity benefits-to-barriers ratios(β=0.05,P=0.003).The influencing factors and pathways of the reported rates of ≥ 1 hour of physical activity in school per day were similar with those of the reported rates of ≥2 hours of overall physical activity per day described above.Conclusion:The dai-ly physical activity time among elementary and junior high school students in Beijing in 2023 fell short of meeting the national requirement.There was a need to build a supportive environment consisting of fami-ly,school,and community for physical activity,to promote the students'sports skills,to establish the idea of independent physical activity,and to ensure that primary and secondary school students were given one hour of physical activity time every day,both inside and outside the school.

Objective:To analyze the regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014.Methods:The Chinese Han students aged 7 to 18 years with complete basic information and height data from 30 mainland provinces (excluding Hong Kong, Macao, Taiwan and Tibet in China) were extracted as participants from 6 successive cross-sectional surveys of the Chinese National Survey on Student′s Constitution and Health (CNSSCH). After excluding extreme and illogical cases, a total of 1 495 182 students were included in the analysis. The data of gross domestic product (GDP) per capita of each province at each survey year were collected from the website of National Bureau of statistics of China. Mann-Kendall trend test was used to analyze the trend of mean height across years. Weighted linear regression model was used to analyze the association between mean height of students aged 7 to18 years and GDP per capita at provincial level. Height difference, height ratio, slope index of inequality (SII) and relative index of inequality (RII) were used to measure the height inequality by gender and age groups.Results:The mean height of Chinese Han students aged 7 to 18 years increased from 144.9 cm in 1985 to 151.8 cm in 2014 ( P<0.05). The height difference between urban and rural students in all age groups was reducing ( P<0.05). The height difference between urban and rural boys aged 13 to 15 years decreased from 5.3 cm in 1985 to 2.5 cm in 2014, and the difference between urban and rural girls aged 7 to 12 years decreased from 4.6 cm in 1985 to 2.4 cm in 2014. The mean height of students aged 7 to 18 years was positively associated with GDP per capita in all survey years for both genders ( P<0.001). Taking Shanghai and Guizhou as the representatives of economically developed and underdeveloped provinces, from 1985 to 2014, the height differences between two provinces were 6.8-9.2 cm, 8.0-12.4 cm and 6.3-8.8 cm for boys aged 7 to 12 years, 13 to 15 years and 16 to 18 years, respectively, and the height ratios were stable at 1.05-1.07, 1.05-1.08 and 1.04-1.05 respectively. From 1985 to 2014, the SII of mean height for boys in three age groups were 4.4-6.2, 4.9-6.7 and 2.5-4.7, respectively. The RII of mean height of boys in three age groups were 1.03-1.05, 1.03-1.04 and 1.01-1.03, respectively. In the same period, the SII of mean height for girls in three age groups were 4.2-6.2, 2.8-4.5 and 2.5-3.9, and the RII were 1.03-1.05, 1.02-1.03 and 1.02, respectively. Conclusion:From 1985 to 2014, the urban-rural inequality of height development among Chinese Han students aged 7 to 18 years was narrowing, but the socio-economic inequality of height persisted and remained at a relatively stable level.