BACKGROUND:The mechanism of programmed death receptor-1(PD-1)effect on osteogenic differentiation of bone marrow mesenchymal stem cells in high glucose environment remains unclear. OBJECTIVE:To explore the effect of PD-1 on osteogenic differentiation of rat bone marrow mesenchymal stem cells in high glucose environment and its regulatory mechanism. METHODS:Rat bone marrow mesenchymal stem cells were randomly divided into normal glucose group(5.6 mmol/L),high glucose group(30 mmol/L),PD-1 overexpression group,PD-1 overexpression no-load group,PD-1 knockdown group,PD-1 knockdown no-load group,and PI3K/AKT pathway inhibitor group(PD-1 knockdown+5 μmol/L LY294002).Rat bone marrow mesenchymal stem cells were cultured in high glucose to simulate the diabetic environment in vitro.The mRNA expression of PD-1 and ligand PD-L1 and the mRNA expression of osteogenic markers Runx2 and OSX in rat bone marrow mesenchymal stem cells were detected by qRT-PCR.The osteogenic differentiation ability was observed by alkaline phosphatase staining and alizarin red staining.Cell proliferation was detected by CCK-8 assay.The protein expressions of PD-1,PD-L1,p-PI3K,and p-AKT were detected by western blot assay. RESULTS AND CONCLUSION:(1)The levels of PD-1 and PD-L1 were significantly increased in the high glucose environment in vitro,and the osteogenic differentiation ability of bone marrow mesenchymal stem cells was inhibited in the high glucose environment.(2)Knockdown of PD-1 expression could promote osteogenic differentiation of bone marrow mesenchymal stem cells,increase cell proliferation activity,and activate the PI3K/AKT pathway.(3)After addition of PI3K/AKT pathway inhibitor LY294002,the ability of bone marrow mesenchymal stem cells to differentiate into osteoblasts decreased.The results show that PD-1 is dependent on the PI3K/AKT signaling pathway to inhibit osteogenic differentiation of rat bone marrow mesenchymal stem cells under high glucose environment.

Objective: To analyze the association between each regional fat mass and total body bone mineral density (BMD) in children and adolescents aged 7-17 years in Beijing, so as to provide theoretical basis and practical guidance for implementing interventions. Methods: From September to December 2020, a stratified cluster random sampling method was used to select 1 423 children and adolescents aged 7-17 years in Tongzhou District, Beijing. Dual energy X-ray absorptiometry (DXA) was employed to measure regional body composition and total body BMD. Multiple linear regression was used to analyze the association between regional fat mass and total body BMD. Results: The median (interquartile range) fat mass values for total body, upper limbs, abdomen, hips, and thighs were 13.51(8.84, 19.21), 1.59(1.08, 2.23), 0.73(0.39, 1.29), 2.32(1.46, 3.26), 5.29(3.59, 7.21)kg, respectively. After adjusting for covariates, the results of multiple linear regression analysis showed that total body fat mass (β=0.010), abdominal fat mass (β=-0.100), and hip fat mass (β=0.104) were significant associations with total body BMD (all P<0.01). Sexstratified analysis revealed that in boys, total body fat mass (β=0.008) and hip fat mass (β=0.058) were positively associated with BMD, while thigh fat mass (β=-0.038) showed a negative association with total body BMD (all P<0.05). In girls, total body fat mass (β=0.013), hip fat mass (β=0.163), and thigh fat mass (β=0.023) were positively associated with total body BMD, whereas abdominal fat mass (β=-0.196) showed a negative association with total body BMD (all P<0.05). Among children and adolescents with body fat percentage below the standard range, within the standard range and above the standard range, total body fat masses were positively associated with total body BMD (β=0.021, 0.016, 0.015); among children and adolescents with body fat percentage within the standard range while upper limb (β=-0.042), abdominal (β=-0.067), and thigh fat mass (β=-0.018) showed negative associations with total body BMD, and hip fat mass demonstrated a positive association with total body BMD (β=0.082) (all P<0.05). Conclusion Regional fat distribution is associated with total body BMD in children and adolescents, with the nature of these associations varying by sex and body fat percentage.

Objective: To explore the relationship between depressive symptoms, negative life events and resilience among primary and secondary school teachers, so as to provide a reference for mental health promotion in school teachers. Methods: During November to December 2022, a questionnaire survey was conducted using convenient cluster sampling method to select 11 332 in service teachers from 38 schools in 8 provinces (cities) including Beijing, Guangdong, Anhui, Hubei, Sichuan, Xinjiang, Liaoning, and Heilongjiang. The Patient Health Questionnaire-9 items, a self developed 21-item Adverse Life Events questionnaire, and a 10-item Conner-Davidson Resilience Scale were used to assess depressive symptoms, experiences of negative life events, and resilience levels of the teachers, respectively. The relationship between depressive symptoms, negative life events and psychological resilience were analyzed by multiple linear regression and stratified regression. Results: The detection rate of depressive symptoms among primary and secondary school teachers was 14.0%. Negative life events of primary and secondary school teachers were positively correlated with depressive symptoms ( r =0.35), while psychological resilience was negatively correlated with depressive symptoms ( r =-0.45) ( P <0.05). After adjusting for possible covariates including gender and marital status, negative life events were positively correlated with depressive symptoms ( β=0.22, P <0.01). Resilience played a moderating role in the association of negative life events with depressive symptoms among primary and secondary school teachers ( B=-0.15, P <0.01). Conclusions Negative life events experiences are associated with higher level of depressive symptoms among school teachers. However, resilience might mitigate the negative effects of negative life events on depressive symptoms, playing a protective role in teachers mental health.

Objective: To explore the longitudinal association between organophosphate esters (OPEs) exposure and blood pressure in children, so as to provide a reference for identifying the effects of OPEs exposure on child health. Methods: A total of 404 children from the Beijing Child Growth and Health Cohort (PROC) were enrolled using a case cohort study design, baseline physical examination, urine collection, questionnaires survey were administered in 2018 and follow up surveys in 2019-2020 and 2023. Participants were divided into case group ( n =140) and control group ( n =264) according to the observation of new onset of high blood pressure during the follow up period. High performance liquid chromatography tandem mass spectrometry was used to detect diethyl phosphate (DEP)，bis (2-chloroethyl) phosphate (BCEP)，bis (1-chloro-2-propyl) phosphate, (BCIPP), diphenyl phosphate(DPHP), dibutyl phosphate (DnBP), bis (1,3-dichloro-2-propyl) phosphate(BDCIPP), bis(2-butoxyethyl) phosphate(BBOEP), bis (2-butoxyethyl) 2-hydroxyethyl phosphate (BBOEHEP), 4-hydroxyphenyl diphenyl phosphate (4-OH-TPHP). Generalized linear mixed models and Quantile g computation models were developed to analyze the longitudinal associations between OPEs individual/mixed exposure and blood pressure in children. Results: The detection range of 9 OPEs metabolites,including DEP, BCEP, BCIPP, DPHP, DnBP, BDCIPP, BBOEP, BBOEHEP and 4-OH-TPHP at three time points (baseline, first follow up and second follow up) were 27.7%-92.1%, 24.0%-99.3% and 39.2%-90.9% respectively. Without adjustment for covariates such as gender, age, body mass index, Tanner stage, parental education, and monthly household income, and family history of hypertension, the increase of BDCIPP concentration and mixed exposure of OPEs may reduce children s systolic blood pressure( β= -0.85，-2.40，95%CI=-1.69--0.01，-3.30--1.50，P <0.05). After adjusting for the covariates, the longitudinal association of individual OPEs or mixed exposure with pediatric BP was not statistically significant ( P >0.05). Conclusion Children are commonly exposed to OPEs, and although no significant longitudinal associations are observed between exposure to OPEs and blood pressure among school aged children in Beijing, it is recommended that child exposure should be minimized whenever possible.

Abstract Healthy lifestyles are the most effective means of promoting the physical and mental health of children and adolescents. In China, unhealthy lifestyles, such as insufficient physical activity, inadequate sleep, poor dietary choices, smoking, and alcohol consumption are prevalent among this population, posing a threat to healthy growth and development. An initial review of global research examining healthy lifestyles reveals a continually evolving landscape, emphasizing the pressing need to update intervention strategies and theories for children and adolescents health promotion in China. The article presents the most recent state of the art healthy lifestyle indicators and the development of healthy lifestyle intervention strategies. In the future, interventions and monitoring of the health lifestyles of children and adolescents should be conducted in conjunction with schools and families which provide optimal settings, while utilizing advanced methods such as the Internet and digital technologies, artificial intelligence, and integrated omics technologies incorporating genetics and the environment.

Objective: To explore sex difference in the cardiovascular health (CVH) status of 6-8 year old children in Beijing, so as to inform the early intervention of CVH related lifestyles. Methods: Based on the Beijing Children s Growth and Health Cohort (PROC), baseline physical examination, sequential questionnaire survey, and laboratory tests were conducted among 1 914 grade 1 students. Children s CVH and its subscales (health behaviors and health factors) scores were calculated according to the Life s Essential 8 (LE 8) index and categorized into high, moderate, and low CVH. CVH scores were reported as medians and interquartile ranges; sex differences were compared using the Chi square test and Wilcoxon test. Results: Among the 1 914 participants, the percentages of high, moderate, and low CVH were 35.7%, 63.5%, and 0.8%, respectively, and the percentages of high, moderate, and low health behavior scores were 25.9%, 67.5%, and 6.6%, respectively, with no statistically significant differences between sex ( χ 2=2.30, 0.07, P >0.05). The rates of high, moderate, and low health factor scores for boys and girls were 61.1%, 36.0%, 2.9% and 71.1%, 28.4%, 0.5%, respectively, with a statistically significant sex difference ( χ 2=31.88, P < 0.01). The overall CVH score was 76.0(70.0, 83.0), 76.0(69.0, 82.0) for boys, and 77.0(71.0, 83.0) for girls. Among the health behavior metrics, sleep scores were the best and physical activity scores were the worst[100.0(90.0,100.0), 40.0(20.0, 80.0 )]; among the health factor metrics, blood glucose scores were the best and lipid scores were the worst[100.0(100.0,100.0), 60.0(40.0,100.0)]. In respect to health factors, there were significant gender differences in body mass index, blood lipids, blood sugar, and blood pressure scores ( Z =-6.92, 3.01, -6.60, -2.30, <0.05), but there were no significant gender differences in diet, physical activity, nicotine exposure, or sleep scores with regards to health behaviors ( Z =0.99, 0.88, -0.13, 0.36, P > 0.05 ). Compared to boys, girls in the low and moderate CVH groups had high health factor scores despite low health behavior scores. Conclusion Most 6 to 8-year-old children in Beijing were found to have relatively good CVH, and optimization of children s CVH status can be achieved by promoting healthier lifestyles and monitoring health factors, especially among boys.

Objective: To understand the prevalence of Lying Flat behaviors and its association with depressive symptoms among Chinese college students, so as to provide a scientific basis for promoting the physical and mental health development of adolescents. Methods: From July to October 2023, three universities were selected through convenient sampling from Jiangxi Province, Liaoning Province and Beijing City, respectively. Selfdesigned questionnaire links were distributed on campus to collect basic information and Lying Flat behaviors among college students, and the Patient Health Questionnaire-9 (PHQ-9) was utilized to screen for students with depressive symptoms. Finally, a total of 4 225 valid questionnaires were obtained. Chisquare was used to compare of report rates of Lying Flat behaviors across different demographic characteristics. Ordered Logistic regression analysis was used to explore the association between Lying Flat behaviors and depressive symptoms, with Z test used to assess variations in the strength of associations. Results: The reporting rates of academic, life, and social Lying Flat were 32.7%, 17.8% and 17.5%, respectively. And 6.7% of the participants were found of all three Lying Flat behaviors simultaneously.Among college students with three Lying Flat behaviors, the constituent ratios of no, mild, moderate and above depressive symptoms were 9.9%, 30.5% and 59.6%, respectively. Additionally, college students who had three Lying Flat behaviors were more likely to show mild, moderate and above depressive symptoms [OR(95%CI)=2.49(1.60-3.87), 7.69(5.01-11.79), P<0.01]. Conclusions Academic Lying Flat behavior is most prevalent among college students. Academic, life and social Lying Flat behaviors are all significantly positively correlated with depressive symptoms. Attention should be paid to the Lying Flat behaviors and college students psychological health conditions to promote their physical and mental health development.

Objective:To evaluate the immunogenicity, safety, and immune persistence of the sequential booster with the recombinant protein-based COVID-19 vaccine (CHO cell) in healthy people aged 18-84 years.Methods:An open-label, multi-center trial was conducted in October 2021. The eligible healthy individuals, aged 18-84 years who had completed primary immunization with the inactivated COVID-19 vaccine 3 to 9 months before, were recruited from Shangyu district of Shaoxing and Kaihua county of Quzhou, Zhejiang province. All participants were divided into three groups based on the differences in prime-boost intervals: Group A (3-4 months), Group B (5-6 months) and Group C (7-9 months), with 320 persons per group. All participants received the recombinant COVID-19 vaccine (CHO cell). Blood samples were collected before the vaccination and after receiving the booster at 14 days, 30 days, and 180 days for analysis of GMTs, antibody positivity rates, and seroconversion rates. All adverse events were collected within one month and serious adverse events were collected within six months. The incidences of adverse reactions were analyzed after the booster.Results:The age of 960 participants was (52.3±11.5) years old, and 47.4% were males (455). The GMTs of Groups B and C were 65.26 (54.51-78.12) and 60.97 (50.61-73.45) at 14 days after the booster, both higher than Group A′s 44.79 (36.94-54.30) ( P value<0.05). The GMTs of Groups B and C were 23.95 (20.18-28.42) and 27.98 (23.45-33.39) at 30 days after the booster, both higher than Group A′s 15.71 (13.24-18.63) ( P value <0.05). At 14 days after the booster, the antibody positivity rates in Groups A, B, and C were 91.69% (276/301), 94.38% (302/320), and 93.95% (295/314), respectively. The seroconversion rates in the three groups were 90.37% (272/301), 93.75% (300/320), and 93.31% (293/314), respectively. There was no significant difference among these rates in the three groups (all P values >0.05). At 30 days after the booster, antibody positivity rates in Groups A, B, and C were 79.60% (238/299), 87.74% (279/318), and 90.48% (285/315), respectively. The seroconversion rates in the three groups were 76.92% (230/299), 85.85% (273/318), and 88.25% (278/315), respectively. There was a significant difference among these rates in the three groups (all P values <0.001). During the sequential booster immunization, the incidence of adverse events in 960 participants was 15.31% (147/960), with rates of about 14.38% (46/320), 17.50% (56/320), and 14.06% (45/320) in Groups A, B, and C, respectively. The incidence of adverse reactions was 8.02% (77/960), with rates of about 7.50% (24/320), 6.88% (22/320), and 9.69% (31/320) in Groups A, B, and C, respectively. No serious adverse events related to the booster were reported. Conclusion:Healthy individuals aged 18-84 years, who had completed primary immunization with the inactivated COVID-19 vaccine 3 to 9 months before, have good immunogenicity and safety profiles following the sequential booster with the recombinant COVID-19 vaccine (CHO cell).

Objective:To investigate the current status of endoscopic treatment for gastroesophageal varices in portal hypertension in China, and to provide supporting data and reference for the development of endoscopic treatment.Methods:In this study, initiated by the Liver Health Consortium in China (CHESS), a questionnaire was designed and distributed online to investigate the basic condition of endoscopic treatment for gastroesophageal varices in portal hypertension in 2022 in China. Questions included annual number and indication of endoscopic procedures, adherence to guideline for preventing esophagogastric variceal bleeding (EGVB), management and timing of emergent EGVB, management of gastric and isolated varices, and improvement of endoscopic treatment. Proportions of hospitals concerning therapeutic choices to all participant hospitals were calculated. Guideline adherence between secondary and tertiary hospitals were compared by using Chi-square test.Results:A total of 836 hospitals from 31 provinces (anotomous regions and municipalities) participated in the survey. According to the survey, the control of acute EGVB (49.3%, 412/836) and the prevention of recurrent bleeding (38.3%, 320/836) were major indications of endoscopic treatment. For primary [non-selective β-blocker (NSBB) or endoscopic therapies] and secondary prophylaxis (NSBB and endoscopic therapies) of EGVB, adherence to domestic guideline was 72.5% (606/836) and 39.2% (328/836), respectively. There were significant differences in the adherence between secondary and tertiary hospitals in primary prophylaxis of EGVB [71.0% (495/697) VS 79.9% (111/139), χ2=4.11, P=0.033] and secondary prophylaxis of EGVB [41.6% (290/697) VS 27.3% (38/139), χ2=9.31, P=0.002]. A total of 78.2% (654/836) hospitals preferred endoscopic therapies treating acute EGVB, and endoscopic therapy was more likely to be the first choice for treating acute EGVB in tertiary hospitals (82.6%, 576/697) than secondary hospitals [56.1% (78/139), χ2=46.33, P<0.001]. The optimal timing was usually within 12 hours (48.5%, 317/654) and 12-24 hours (36.9%, 241/654) after the bleeding. Regarding the management of gastroesophageal varices type 2 and isolated gastric varices type 1, most hospitals used cyanoacrylate injection in combination with sclerotherapy [48.2% (403/836) and 29.9% (250/836), respectively], but substantial proportions of hospitals preferred clip-assisted therapies [12.4% (104/836) and 26.4% (221/836), respectively]. Improving the skills of endoscopic doctors (84.2%, 704/836), and enhancing the precision of pre-procedure evaluation and quality of multidisciplinary team (78.9%, 660/836) were considered urgent needs in the development of endoscopic treatment. Conclusion:A variety of endoscopic treatments for gastroesophageal varices in portal hypertension are implemented nationwide. Participant hospitals are active to perform emergent endoscopy for acute EGVB, but are inadequate in following recommendations regarding primary and secondary prophylaxis of EGVB. Moreover, the selection of endoscopic procedures for gastric varices differs greatly among hospitals.

Hip fracture in the elderly is characterized by high incidence, high disability rate, and high mortality and has been recognized as a public health issue threatening their health. Surgery is the preferred choice for the treatment of elderly patients with hip fracture. However, lower extremity deep venous thrombosis (DVT) has an extremely high incidence rate during the perioperative period, and may significantly increase the risk of patients′ death once it progresses to pulmonary embolism. In response to this issue, the clinical guidelines and expert consensuses all emphasize active application of comprehensive preventive measures, including basic prevention, physical prevention, and pharmacological prevention. In this prevention system, basic prevention is the basis of physical and pharmacological prevention. However,there is a lack of unified and definite recommendations for basic preventive measures in clinical practice. To this end, the Orthopedic Nursing Professional Committee of the Chinese Nursing Association and Nursing Department of the Orthopedic Branch of the China International Exchange and Promotive Association for Medical and Health Care organized relevant nursing experts to formulate Expert consensus on perioperative basic prevention for lower extremity deep venous thrombosis in elderly patients with hip fracture ( version 2024) . A total of 10 recommendations were proposed, aiming to standardize the basic preventive measures for lower extremity DVT in elderly patients with hip fractures during the perioperative period and promote their subsequent rehabilitation.