Objective: To investigate the distribution characteristics and related factors of weight loss behavior among middle school students in Shanghai, so as to provide a reference for guiding scientific weight loss among middle school students. Methods: From May to June 2021, a stratified cluster random sampling method was used to select 16 758 junior and high school students in 16 districts of Shanghai. Youth Risk Behavior Surveillance System was administered to assess the basic condition and weight loss behaviors of the students. An unordered multinomial Logistic regression model was employed to analyze the factors associated with weight loss behaviors. Results: A total of 5 881 (35.09%) reported engaging in exercise for weight loss, 6 344 (37.86%) reported dieting for weight loss, and 461 (2.75%) engaged in unhealthy weight loss behaviors. The unordered multinomial Logistic regression analysis indicated that compared with the no weight loss behavior group, students from urban areas( OR =1.35,95% CI =1.10-1.66), those with Internet addiction ( OR =1.71,95% CI =1.23-2.38), those with victims of bullying ( OR =2.09, 95% CI =1.68-2.61), those experiencing insomnia ( OR =2.33,95% CI = 1.74-3.11), those feelings of sadness or despair ( OR =3.10, 95% CI =2.42- 3.97 ), and those who perceived their body weight as slightly heavy ( OR =2.77, 95% CI = 2.17-3.55) or very heavy ( OR =3.41, 95% CI =2.44-4.75) were more likely to engage in unhealthy weight loss behaviors ( P <0.05). Conclusions There are significant differences in weight loss behaviors among middle school students with varying characteristics in Shanghai. Negative emotions such as insomnia and feelings of sadness or despair, Internet addiction, cognitive bias in weight and experiences of bullying are identified as related factors for unhealthy weight loss behaviors. Targeted intervention measures should be implemented to guide students towards scientific approaches to weight management.

Objective: To understand the subjective and objective comfort evaluations of students from different age groups on desks and chairs, so as to provide reference for standardized allocation and use of desks and chairs. Methods: From January to April 2024, a total of 2 446 students were selected from 26 schools in 13 districts (counties/cities) in Shanghai, Tianjin, and Wuxi from Jiangsu Province by using cluster random method, including students in kindergartens, primary schools, junior high schools,senior high schools, colleges and universities. Standardized procedures were used to measure the height and weight of participants, and the matching desks and chairs models were selected according to the height. The subjective comfort of students on matching desks and chairs was investigated, and their objective comfort was evaluated by using a self designed questionnaire. The χ 2 test was used to analyze the differences of subjective perception and objective evaluation in comfort between different types of desks and chairs. Results: About 84.1% of the students subjectively thought that large desks and small chairs were very comfortable or relatively comfortable, followed by large desks and chairs (75.7%), and the proportion of small desks and chairs was the lowest among the three types (46.2%), and the difference was statistically significant ( χ 2=722.46, P <0.01). The reporting rates of primary school, junior high school and senior high school students who subjectively considered large desks and chairs to be very comfortable/relatively comfortable were higher than that of other types of desks and chairs, and the differences were statistically significant ( χ 2=297.49, 252.82, 343.67, P <0.01). However, there was no significant difference in the subjective comfort evaluation of different types of desks and chairs among kindergarten children ( χ 2=3.21, P >0.05), and 66.3% of the students in colleges and universities felt very comfortable/relatively comfortable when they used the matching standard desks and chairs. The objective evaluation results of the comfort for the three types of desks and chairs were consistent with the subjective evaluation, but the proportions of the objective evaluation as very comfortable/relatively comfortable were higher than that of the subjective evaluation ( χ 2=20.76- 813.47, P <0.01). Conclusions Large desks and chairs, as well as large desks with small chairs are perceived comfortable, while small desks and chairs are perceived less comfortable. It is recommended to match the large desks and chairs or large desks and small chairs that are suitable for them according to the "standard", to promote physical and mental health of students.

Objective: To investigate the differences in the comfort of desks and chairs furniture among students with different body types according to the standard, so as to provide a reference for guiding students with overweight and obesity to choose the correct study furniture and revising the standards. Methods: From January to April 2024, 2 443 students from 26 schools in 13 districts (counties/cities) in Shanghai, Tianjin, and Jiangsu Province were selected by the cluster random sampling method to conduct physical examination. The subjective and objective evaluations of the comfort of height matched desks and chairs were investigated. The students were divided into non overweight, overweight, and obesity groups according to relevant criteria, and stratified analysis was performed. The χ 2 test was used to analyze differences in the comfort evaluations of desks and chairs among students with different body types. Results: Among the 2 443 students surveyed, 16.7% and 12.6% were respectively classified as overweight and obese. All students assigned the highest comfort ratings to large desks and small chairs (84.1%), and consistency was observed between students subjective and objective evaluations. The reporting rate of samll desks and chairs of obesity students subjective evaluation was lower (36.8%) than that of overweight and non overweight/obesity students (52.1%, 48.0%) ( χ 2=14.63, P <0.01). The overweight and obese group of primary school students had a worse evaluation of the comfort of large desks and chairs and small desks and chairs than those of the non overweight and obese groups( χ 2=15.78, 7.63, P <0.05). Among high school students, the overweight and obese group had worse evaluation of the comfort of large desks and chairs, as well as large desks and small chairs, than those of the non-overweight and obese groups( χ 2=9.62, 11.77, P <0.05). The objective evaluations revealed low compliance ratings on the posture of the thighs and calves for naturally forming an angle greater than 90° (55.6%), and headroom height under the table (50.3%) with small desks and chairs ( χ 2=94.05, 166.47, P <0.05). Conclusions Compared with non overweight/obese students, students with overweight and obese students report poor comfort evaluations of height matched desks and chairs. Revision of the standard should consider the body types of students, and evaluations of the comfort of desks and chairs furniture by students with overweight and obesity should be improved.

Objective: To investigate the association of moderate to vigorous intensity physical activity (MVPA) and screen time (ST) with emotional and behavioral problems in middle school students, so as to provide a basis for improving the mental health level of adolescents. Methods: Four public junior high schools in Jinshan District, Shanghai were selected by random cluster method from September 19 to October 18, 2023, with 779 first grade students included. Strengths and Difficulties Questionnaire (SDQ), as well as physical activity and screen time were collected. Binary Logistic regression analysis was used to investigate the association between MVPA, ST and different dimensions of emotional and behavioral problems. Results: Students with MVPA<60 min/d accounted for 82.4%, and with ST>2 h/d accounted for 29.5%. The abnormal rate of SDQ dimensions among students ranged from 6.8 % to 19.3%, with the highest abnormal rate observed in behavioral problems. The results of binary Logistic regression analysis showed that, compared with high level of MVPA, students with low level of MVPA had a significantly increased risk of developing problems in prosocial behavior [ OR (95% CI )=2.16(1.37-3.41), P <0.05]. Compared with low level ST, students with high level had an increased risk of experiencing emotional symptoms, behavioral problems and peer interaction problems [ OR (95% CI )=2.00(1.25-3.22), 2.00(1.41-2.84), and 1.69(1.22-2.33), P <0.05]. Compared with high MVPA and low ST, students with low MVPA and high ST had an increased risk of developing problems in the dimensions of conduct problems, prosocial behavior, and overall difficulty score [ OR (95% CI )=1.92(1.13-3.23), 2.73(1.56-4.77), and 2.07(1.19-3.60), P <0.05]. Conclusions Physical activity and screen time are related to emotional and behavioral problems in middle school students. Insufficient physical activity time and excessive screen time might increase the risk of emotional and behavioral problems. Interventions can be administered on physical activity and screen time among adolescents to promote their mental health.

ObjectiveTo unveil the mechanism of Jianpi Huogu prescription （JPHGP） in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head （SONFH） by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal， model， low-， medium-， and high-dose （2.5， 5， 10 g·kg^-1， respectively） JPHGP， and Jiangushengwan （1.53 g·kg^-1） groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg^-1 on days 1 and 2， and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg^-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection， and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head， and the number of adipocytes， the rate of empty bone lacunae， and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）， apolipoprotein A1 （ApoA1）， and apolipoprotein B （ApoB）. At the same time， the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed， and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking， immunohistochemistry， and Western blot. ResultsCompared with the normal group， the model group showcased thinning of the femoral head， trabecular fracture， karyopyknosis， subchondral cystic degeneration， increases in the number of adipocytes and the rate of empty bone lacunae （P<0.01）， a reduction in the trabecular area （P<0.01）， decreases in BMD， Tb.Th， Tb.N， and BV/TV， and increases in Tb.Sp and BS/BV （P<0.01）. Compared with the model group， the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae， an increase in the trabecular area （P<0.05， P<0.01）， rises in BMD， Tb.Th， Tb.N， and BV/TV， and decreases in Tb.Sp and BS/BV （P<0.05， P<0.01）. Compared with the normal group， the model group showcased raised serum levels of TG， TC， LDL， and ApoB and lowered serum levels of HDL and ApoA1 （P<0.01）. Compared with the model group， the JPHGP groups had lowered serum levels of TG， TC， LDL， and ApoB （P<0.05， P<0.01） and a risen serum level of ApoA1 （P<0.05， P<0.01）. Moreover， the serum level of HDL in the high-dose JPHGP group increased （P<0.01）. A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head， and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation， lipids， apoptosis， and osteoclast differentiation. Molecular docking， immunohistochemistry， and Western blot results showed that compared with the normal group， the model group displayed increased content of 5-lipoxygenase （5-LO） and peroxisome proliferator-activated receptor γ （PPARγ） in the femoral head （P<0.01）. Compared with the model group， medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ （P<0.05， P<0.01）. ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.

ObjectiveTo unveil the mechanism of Jianpi Huogu prescription （JPHGP） in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head （SONFH） by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal， model， low-， medium-， and high-dose （2.5， 5， 10 g·kg^-1， respectively） JPHGP， and Jiangushengwan （1.53 g·kg^-1） groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg^-1 on days 1 and 2， and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg^-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection， and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head， and the number of adipocytes， the rate of empty bone lacunae， and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）， apolipoprotein A1 （ApoA1）， and apolipoprotein B （ApoB）. At the same time， the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed， and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking， immunohistochemistry， and Western blot. ResultsCompared with the normal group， the model group showcased thinning of the femoral head， trabecular fracture， karyopyknosis， subchondral cystic degeneration， increases in the number of adipocytes and the rate of empty bone lacunae （P<0.01）， a reduction in the trabecular area （P<0.01）， decreases in BMD， Tb.Th， Tb.N， and BV/TV， and increases in Tb.Sp and BS/BV （P<0.01）. Compared with the model group， the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae， an increase in the trabecular area （P<0.05， P<0.01）， rises in BMD， Tb.Th， Tb.N， and BV/TV， and decreases in Tb.Sp and BS/BV （P<0.05， P<0.01）. Compared with the normal group， the model group showcased raised serum levels of TG， TC， LDL， and ApoB and lowered serum levels of HDL and ApoA1 （P<0.01）. Compared with the model group， the JPHGP groups had lowered serum levels of TG， TC， LDL， and ApoB （P<0.05， P<0.01） and a risen serum level of ApoA1 （P<0.05， P<0.01）. Moreover， the serum level of HDL in the high-dose JPHGP group increased （P<0.01）. A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head， and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation， lipids， apoptosis， and osteoclast differentiation. Molecular docking， immunohistochemistry， and Western blot results showed that compared with the normal group， the model group displayed increased content of 5-lipoxygenase （5-LO） and peroxisome proliferator-activated receptor γ （PPARγ） in the femoral head （P<0.01）. Compared with the model group， medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ （P<0.05， P<0.01）. ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.

Objective: To investigate the effect of a free pit and fissure sealing program for caries prevention on first permanent molars (six-year molars) in Haizhu District, Guangzhou, three years after its implementation in 2019. The study aims to provide a reference for the future development of pit and fissure sealing programs for children’s first permanent molars and the effective prevention and treatment of permanent tooth caries in children. Methods: A random sampling method was used. In 2022 October, 270 sixth-grade primary-school students in Haizhu District, Guangzhou, who had participated in the free pit and fissure sealing program for their first permanent molars in 2019, were placed in the sealant group. Another 223 age-matched students from the same schools who met the criteria for the pit and fissure sealing but did not participate in the program were placed in the control group. The first permanent molars of students in both groups were examined. The retention status of the sealant and the caries status of the first permanent molars were recorded for the sealant group, and the caries status of the first permanent molars was recorded for the control group. The 2022 results were compared with the results of a prior pit and fissure sealing program implemented in Haizhu District in 2011, three years after its implementation. Results: Compared with the control group, the caries rate in the sealant group decreased (15.56% vs. 21.52%, P>0.05), the caries detection rate was significantly lower (6.12% vs. 9.00%, P<0.001), and the mean number of decayed teeth was significantly reduced (0.19 vs. 0.37, P<0.001). Compared with the results of the pit and fissure sealing program in Haizhu District in 2011 (in 2014, the retention rate of the first permanent molar sealant was 65.56%, the intact rate was 42.25%, and the protection rate was 38.34%), the results of the pit and fissure sealing program in Haizhu District in 2019 [in 2022, the retention rate of the first permanent molar sealant was 86.09% (P<0.001), the intact rate was 47.00% (P<0.001), and the protection rate was 51.97%] were improved. Conclusion The quality of the pit and fissure sealing program for the first permanent molars in Haizhu District, Guangzhou in 2019 was good. It reduced the caries detection rate, and the retention rate of the sealant was maintained at a high level. However, the intact rate was less than 50%; therefore, it is necessary to vigorously promote oral-health education and examinations in all age groups, and to be attentive to the re-examination and re-sealing of fissure sealants.

Objective: To understand the moderating effect of cohabitation with parents on the association between peer dating behavior and sexual behaviors among secondary vocational school students, so as to provide a scientific basis for preventing sexual behaviors among secondary vocational school students. Methods: From March to April 2021, an electronic questionnaire survey was conducted among 3 180 students from 6 vocational schools in Shanghai (urban, suburban, exurban) and Shaanxi (Shangluo, Ankang, Baoji) using cluster sampling. Spearman correlation analysis was used to investigate the relationship of cohabitation with parents, peer dating behavior and sexual behaviors among secondary vocational school students. Binary Logistic regression analysis was performed to investigate the role of cohabitation with parents on peer dating behavior and sexual behaviors among secondary vocational students. Results: There was a significant negative between cohabitation with parents and sexual ( r =-0.04); and there was a positive correlation between peer dating behavior and sexual behaviors ( r =0.24), as well as cohabitation with parents and peer dating behavior ( r =0.04)( P <0.05). Multivariable Logistic regression analysis showed an association between peer dating behavior and the occurrence of sexual behaviors ( OR=2.79-12.95, P <0.05). Cohabitation with parents played a moderating role in the association between peer dating behavior and sexual behaviors, and a signification interaction was found between cohabitation with parents and reporting that a small part or about half of their peers had dating behavior ( OR =0.48, P <0.05). Conclusions The more peers dating behavior are associated with a higher risk of sexual behaviors among secondary vocational school students, and cohabitation with parents can partly reduce this risk. School and family sexuality education for secondary vocational students should be strengthened to improve their interpersonal skills and decision-making, and ability to resist peer pressure, so as to reduce their risk of sexual behaviors.

Objective:To analyze the association between moderate-to-vigorous-physical activity (MVPA) and obesity, poor sleep quality, as well as multimorbidity in 7- to 8-year-old children in Shanghai City.Methods:From September to November 2023, a cluster sampling method was used to select second-grade students from four primary schools in Jinshan District, Shanghai. Three-axis acceleration motion sensors (GT3X+, Acti-graph) were used to monitor daily physical activity for seven consecutive days. A multivariate logistic regression model was used to analyze the association between MVPA duration characteristics and obesity, poor sleep quality and multimorbidity in school-age children.Results:Of the 937 study participants, 512 (54.64%) were boys and 425 (45.36%) were girls. Among them, 89 (9.50%) were obese and 782 (83.46%) had poor sleep quality. A total of 77 cases (8.22%) were affected by obesity and poor sleep quality. The average daily MVPA time was (45.97±15.87) minutes, and the MVPA attainment rate was 17.18%. The multivariate logistic regression model analysis showed that, after adjusting for covariates, the daily average MVPA time was negatively associated with the risk of obesity ( OR=0.982, 95% CI: 0.968-0.997), as well as multimorbidity ( OR=0.981, 95% CI: 0.965-0.997). The risk of obesity, poor sleep quality and multimorbidity in <1 d was 2.228 ( OR=2.228, 95% CI: 1.398-3.549), 1.702 ( OR=1.702, 95% CI: 1.141-2.540) and 2.150 ( OR=2.150, 95% CI: 1.310-3.528) times higher than that in ≥1 d. Conclusion:Obesity, poor sleep quality and multimorbidity of school-age children are closely related to the level of moderate-to-vigorous physical activity.

Objective:To establish a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for accurate determination of plasma Lyso-GL-3 concentration.Method:Solid phase extraction technology was used to process plasma samples, and under positive ion mode and multiple reaction monitoring (MRM) conditions, LC-MS/MS was used to determine the concentration of Lyso-GL-3. The linear range, detection and quantification limits, accuracy, precision, matrix effect, carrier effect of the method, and plasma sample stability were validated. And the accuracy of Lyso-GL-3 positive patients was compared by combining enzymatic and genetic testing results.Result:Lyso-GL-3 had good linearity in the range of 1.25-400 nmol/L. The detection limit and quantification limit were 0.15 nmol/L and 0.50 nmol/L, respectively. The spiked recovery rate was 88.78%-108.96%. The coefficient of variation ( CV) for intra batch precision, inter batch precision, and matrix effect were all less than 15%, the result of carrier effect was 0.55%. Plasma samples could be stably stored for 30 days under refrigeration conditions. The clinical conformity of the patient was 100%. Conclusion:The established LC-MS/MS detection method for plasma Lyso-GL-3 concentration takes 2.5 minutes, which is simple, fast, accurate, and reliable.