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.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Objective To investigate the efficacy of antibacterial photodynamic therapy(aPDT)as an adjunct to subgingival scaling and root planning in the treatment of chronic periodontitis.Methods This study followed medical ethics guidelines,and informed consent was obtained from all patients.Sixteen patients were recruited for this random-ized split-mouth controlled trial.The control group underwent subgingival scaling and root planning(SRP),while the ex-perimental group received subgingival scaling and root planing plus aPDT treatment using Perowave? with a toluidine blue O solution photosensitizer.The probing pocket depth(PD),recession,plaque index(PLI),bleeding index(BI)and proportion of positive sites of bleeding on probing(BOP)(BOP%)at all sites were examined at baseline(before treat-ment)and at 1,3 and 6 months after treatment.Results Follow-up was completed for 13 patients.On the control side,356 teeth were tested at 2 136 sites.A total of 360 teeth on the test side and 2 160 sites were included in the study.Before treatment,there was no significant difference in the baseline indicators between the two groups.After treatment,both groups showed significant improvement in clinical parameters,including PD,PLI,BI,and BOP%,compared with baseline.At 3 months,the BOP%and PLI in the experimental group were significantly lower than those in the control group(P＜0.05).The improvement in BOP%and PLI in the experimental group was significantly greater than that in the control group 3 months after treatment(P＜0.05).Conclusion aPDT,as an adjuvant treatment to SRP for chronic periodontitis,can improve gingival bleeding and control periodontal inflammation in the early stage.

Objective:To investigate the risk factors and cumulative risk of myopia in children and adolescents, providing a basis for identifying cumulative risk factors in preventing and controlling myopia.Methods:Baseline data from the mental and physical health cohort of children and adolescents established in Inner Mongolia Autonomous Region were used. A stratified random cluster sampling method was adopted to select 138 974 students from fourth to twelfth grade as participants. Distance visual exams, refractive assessments, and questionnaires were conducted on the included students. Logistic regression analysis was used to evaluate each risk factor's impact on myopia's prevalence. The number of risk factors was summed to form a cumulative risk score, and logistic regression analysis was conducted to examine the association between the cumulative risk score and the prevalence of myopia. Additionally, the association between the cumulative risk score of myopic students and their degree of refractivity was analyzed using a generalized estimating equation.Results:The study found a high prevalence of myopia among children and adolescents at baseline (70.2%). Girls exhibited a higher prevalence (74.8%) than boys (65.6%), urban areas (74.3%) surpassed suburban ones (68.6%), and the incidence was greater in high schools (80.3%) compared to middle schools (75.3%), which, in turn, was higher than in elementary schools (57.7%) (all P<0.05). Analysis of risk factors revealed that children and adolescents experiencing improper reading and writing distances ( OR=1.10, 95% CI: 1.07-1.13), excessive homework ( OR=1.09, 95% CI: 1.06-1.12), insufficient sleep ( OR=1.10, 95% CI: 1.07-1.13), having myopic father ( OR=1.98, 95% CI: 1.91-2.05), having myopic mother ( OR=2.04, 95% CI: 1.97-2.10), or using classroom chairs not matched to their height faced ( OR=1.04, 95% CI: 1.01-1.07) increased myopia risks. Additionally, the prevalence and significant odds ratio of myopia increased with the increase in cumulative risk score, with every additional unit of cumulative risk score increasing the right eye's refractive error by -0.10 D. Conclusion:The presence of multiple factors and their comprehensive score increases the prevalence of myopia in children and adolescents.

Objective: To explore the current status and progress of regional school health work to provide policy reference for school health improvement. Methods: Survey data on school health work in Tianjin from 2019, 2021 and 2023 was used. School health staff allocation and expenditure of the health administrative department, CDC and education department, as well as the annual implementation of health education, prevention and control of common diseases and infectious diseases, sports activities and food nutrition in primary and secondary schools were analyzed. Statistical analysis was conducted using KruskalWallis test, Chisquare test, and Fishers exact test. Results: The number of school health staff in the health commissions and education departments from 2019, 2021 and 2023 was relatively stable. Parttime staffs were often employed by health commissions while fulltime staffs were mainly employed by education departments. The number of school health staff at CDCs increased gradually (H=12.65, P<0.01). School health expenditure of administrative departments and schools in 2021 and 2023 increased significantly compared with that in 2019 (H=22.28, 23.75, P<0.05). More than 95% of schools set up clinics or health care rooms, and about 97% of schools had school health technicians or health teachers. More than 90% of schools had health education courses over 4 hours per semester. The rate of mental health education increased by year (86.87%, 89.91%, 96.30%, Z=2.40，P<0.05). Lack of courses regarded safety emergency and risk avoidance, growth and development, and adolescent health education. The provision rate of psychological counseling services (89.00%, 97.25%, 100.00%) and psychological problem prevention and control (56.12%, 71.56%, 81.48%) also increased by year (Z=3.83, 3.96, P<0.01). The implementation rates of prevention and control of poor vision, dental caries, overweight and obesity were all higher than 80%, and the prevention and control rate of abnormal spinal curvature showed an increasing trend (38.78%, 77.06%, 72.22%, Z=4.87, P<0.01). More than 90% of schools met the standard for physical education class hours, and the proportion of schools conducting at least 30 minutes of recess physical activities every day increased year by year (65.00%, 80.73%, 85.98%, Z=3.59, P<0.01). All schools did not have shops. Conclusions School health work in Tianjin is effective and constantly developing. It is necessary to continue to increase the investment of human resources and expenditure in school health, explore the approaches of cooccurrence and prevention of common diseases, and improve the school sports and nutrition environment.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.