Background The job content of aircraft maintenance workers is complex, with high intensity and high requirements, and they are prone to work-related musculoskeletal disorders (WMSDs), but related research is relatively rare. Objective To investigate the positive rate of WMSDs among aircraft maintenance workers, evaluate ergonomic load, and analyze the risk factors of WMSDs. Methods We used a self-compiled questionnaire for WMSDs and the Quick Exposure Checklist (QEC) to investigate the basic situation, positive rate of WMSDs, and the ergonomic load of 2271 male maintenance workers in 6 departments of an aircraft maintenance company, including airline maintenance, overall overhaul, accessory/landing gear overhaul, engine overhaul, product customization, and power assist. We used a logistic regression model to analyze the risk factors of WMSDs in the neck, shoulder, hand/wrist, and lower back. Results The positive rate of WMSDs in the past 12 months was 70.4% (1598/2271) and the positive rate of WMSDs in different body parts ranged from 6.6% to 49.5%, with the top three parts of lower back, neck, and knee, respectively. There were statistically significant differences in the positive rate among different departments (P<0.05). The average QEC scores for neck, hand/wrist, and back (static) were moderate, while those for shoulder and back (dynamic) were high, and the body part specific positive rate of WMSDs increased with the increase of ergonomic load level. Working years (5-<10 years, ≥20 years), working with back flexed or twisted or side bent (moderately, excessively), high maximum force level exerted by one hand, and feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of lower back pain (OR=1.486, 1.505; 2.151, 3.769; 1.637; 2.110, 2.407; 1.637, 1.794; P<0.05). Working years (15-<20 years, ≥20 years), working with head/neck bent or twisted (occasionally, continuously), feeling difficult (sometimes) and stressful (very) while working were associated with higher risks of neck pain (OR=1.731, 1.586; 3.732, 8.341; 1.633; 1.696; P<0.05). Working years (15-<20 years, ≥20 years), working with hands in a high position (at shoulder or above), very frequent shoulder/arm movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of shoulder pain (OR=1.587, 1.709; 1.299; 1.521; 1.643, 2.239; 1.659, 1.977; P<0.05). Working with wrist at deviated or bent angle, high repetition of similar movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of hand/wrist pain (OR=1.692; 1.670; 1.827, 2.884; 2.190, 2.625; P <0.05) . Physical exercise after work (≥3 times·week⁻¹) was associated with a lower risk of neck pain (OR=0.582, P<0.05). Shift workers were at a lower risk of shoulder pain and hand/wrist pain (OR=0.737 and 0.554, P<0.05). Conclusion The high positive rate of WMSDs symptoms among aircraft maintenance workers is related to individual, occupational ergonomic, and psychological factors, and active prevention and intervention should be taken.

Objective To assess the current state and influencing factors of multi-site work-related musculoskeletal disorders (WMSDs) among front-line employees in the assembly workshop of an automobile manufacturing enterprise. Methods A total of 394 front-line workers in the assembly workshop of an automobile manufacturing enterprise in Beijing City were selected as the research subjects using the judgmental sampling method. The Chinese version Musculoskeletal Disorders Questionnaire was used to assess the presence of WMSDs over the past 12 months in nine body regions: neck, shoulders, upper back, lower back, elbows, wrists, hips and thighs, knees, ankles and feet. The multivariable logistic regression was employed to investigate the influencing factors. Results The detection rate of overall WMSDs was 32.7% (129/394), with the top three single-site WMSDs being in the neck, shoulders, and lower back, and their detection rates were 14.0%, 12.7% and 9.6%, respectively. The detection rate of multi-site WMSDs was 17.8% (70/394). The result of multivariable logistic regression analysis revealed that workers who turned or bent their upper body while keeping their legs stationary, frequently performed wrist flexion/extension/lateral bending/rotation, or stood for prolonged period of time had significantly higher risks of developing multi-site WMSDs compared with those who did not (all P<0.05). Workers who perceived uncomfortable workplace lighting had higher risk of multi-site WMSDs than those who perceived it as comfortable (P<0.01). Conclusion The development of multi-site WMSDs among workers in the assembly workshop of this automobile manufacturing enterprise is strongly related to poor working postures at work.

ObjectiveTo identify the prototypical components and metabolites absorbed into blood and cerebrospinal fluid of Schisandrae Chinensis Fructus（SCF） based on sequential metabolism combined with liquid chromatography-mass spectrometry. MethodBlood and cerebrospinal fluid samples of integrated metabolism， intestinal metabolism and hepatic metabolism were collected from male SD rats after gavage and in situ intestinal perfusion administration， and ultra-performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry（UPLC Q-Exactive Orbitrap MS） was used to analyze and compare the differences in the spectra of SCF extract， blank plasma， administered plasma， blank cerebrospinal fluid and administered cerebrospinal fluid with ACQUITY UPLC BEH Shield RP18 column（2.1 mm×100 mm， 1.7 µm）， the mobile phase was acetonitrile（A）-0.1% formic acid aqueous solution（B） for gradient elution（0-7 min， 95%B； 7-12 min， 95%-35%B； 12-17 min， 35%-15%B； 17-20 min， 15%-12%B； 20-22 min， 12%-5%B； 22-23 min， 5%B； 23-25 min， 5%-95%B； 25-28 min， 95%B）. And heated electrospray ionization（HESI） was used with positive and negative ion modes， the scanning range was m/z 100-1 500. The prototypical constituents and their metabolites absorbed into blood and cerebrospinal fluid of SCF were identified according to the retention time， characteristic fragments， molecular formulae and the information of reference substances. ResultA total of 42 chemical components were identified in the extract of SCF， including lignans， flavonoids， amino acids， tannins， and others， of which lignans were the main ones. A total of 27 prototypical components and 14 metabolites were identified in plasma samples from different sites. A total of 15 prototypical components and 9 metabolites were identified in cerebrospinal fluid. The main metabolic reactions involved in the formation of metabolites were mainly demethylation， methylation， demethoxylation and hydroxylation. ConclusionThrough the systematic identification of the prototypical components and metabolites of SCF in rats， it provides data support for further better exploring the material basis of SCF in the treatment of central nervous system diseases.

ObjectiveTo examine the inhibitory effects of berberine compounds， including columbamine， on acetylcholinesterase from the perspectives of drug-target binding affinity and kinetics and explore the blood-brain barrier （BBB） permeability of these compounds in different multi-component backgrounds. MethodThe median inhibitory concentration （IC₅₀） of acetylcholinesterase by berberine compounds including columbamine was measured using the Ellman-modified spectrophotometric method. The binding kinetic parameters （K_off） of these compounds with acetylcholinesterase were determined using the enzyme activity recovery method. A qualitative analysis of the ability of these components to penetrate the BBB and arrive at the brain tissue in diverse multi-component backgrounds （including medicinal herbs and compound formulas） was conducted using ultra performance liquid chromatography-high resolution mass spectrometry （UPLC-HRMS）. ResultBerberine compounds， including columbamine， exhibited strong inhibition of acetylcholinesterase， with IC₅₀ values in the nanomolar range. Moreover， they displayed better drug-target binding kinetics characteristics （with smaller K_off values） than the positive control of donepezil hydrochloride （P<0.01）， indicating a longer inhibition duration of acetylcholinesterase. Berberine components such as columbamine could penetrate the BBB to arrive at brain tissue in the form of a monomer， as well as in the multi-component backgrounds of Coptis and Phellodendri Chinensis Cortex medicinal extracts and the compound formula Huanglian Jiedutang. ConclusionThese berberine compounds such as columbamine exhibit a strong inhibitory effect on acetylcholinesterase and can arrive at brain tissue in multi-component backgrounds. In the level of pharmacological substance， this supports the clinical efficacy of compound Huanglian Jiedutang in improving Alzheimer's disease， providing data support for elucidating the pharmacological basis of compound Huanglian Jiedutang.

Objective:To evaluate the reliability and validity of a questionnaire assessing the leadership qualities of primary healthcare institution managers, and to further clarify the current state of leadership development among management teams of community health service centers in Shanghai.Methods:The study was a cross-sectional survey. It was conducted from August to December 2021, and used a stratified sampling method. Using a self-developed questionnaire for primary healthcare institution managers, we surveyed 279 individuals from 10 community health service centers in Shanghai, including management teams, middle-level cadres, general practitioners, and staff from health administrative departments in their respective districts. Leadership qualities were evaluated on five dimensions: inspiration, decisiveness, control, influence, and foresight. Cronbach′s α coefficient and split half coefficient were used to analyze the reliability of the questionnaire, and confirmatory factor analysis was used to assess the structural validity of the scale.Results:The overall Cronbach′s α reliability of the questionnaire for the comprehensive management of community health service centers was 0.96, and the Spearman-Brown split-half coefficient was 0.94. The validity analysis yielded a KMO value of 0.975, the RMSEA for factor analysis was 0.085, and the adaptation indexes all met the model adaptation conditions. Of the 279 participants, 174 were female (62.4%), 257 held a mid-level or higher professional title (92.1%). The overall leadership score of the community health service center management teams was (4.43±0.59), with the dimensions ranked from highest to lowest as follows: inspiration (4.52±0.55), decisiveness (4.46±0.62), control (4.44±0.60), influence (4.42±0.63), and foresight (4.32±0.69). The foresight score was significantly lower than the other four dimensions (all P<0.05). Conclusions:The questionnaire used to assess the leadership qualities of primary healthcare institution managers is reliable and valid. The development of leadership qualities among management teams of community health service centers in Shanghai is unbalanced, with foresight being the weakest dimension.

Objective: To analyze the current status and related factors of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing, so as to provide a basis for comprehensive public health interventions for common diseases. Methods: Through stratified cluster random sampling in October 2022, a total of 11 262 junior high school, senior high school, and vocational high school students in 16 districts of Beijing were surveyed with self administered questionnaires, physical examinations and visual acuity examinations. The χ 2 test and binary Logistic regression model were used to analyze group differences in the comorbidity of myopia, obesity and depression symptoms and factors influencing the comorbidity. Stratified analysis was applied to analyze the associations between health risk behaviors and the comorbidity. Results: The detection rate of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing was 3.35%, the comorbidity rate among vocational high school students (4.61%) was higher than that in junior high school students (2.80%) and senior high school students (3.41%). The comorbidity rate was higher among students in suburban areas (3.66%) than that in urban areas (2.92%), and the differences was statistically significant ( χ 2=15.02, 4.63, P <0.05). Binary Logistic regression analyses indicated that middle school students with poor dietary behaviors ( OR =1.59) and excessive screen time ( OR =1.70) were associated with elevated risk of comorbidity of myopia, obesity, and depression symptoms. Both boys and girls with poor dietary behaviors ( OR =1.63, 1.69) and excessive screen time ( OR =1.45, 2.23) had elevated likelihood of comorbidity of myopia, obesity and depression symptoms. Students in junior high school and senior high school with poor dietary behaviors ( OR =2.16, 1.47) and excessive screen time ( OR =2.20, 1.63 ) had elevated likelihood of comorbidity of myopia, obesity, and depression symptoms ( P <0.05). Conclusions The current status of comorbidity of myopia, obesity, and depression symptoms among middle school students in Beijing is concerning. Schools and parents should work together to guide students to develop healthy behaviors such as balanced diet and moderate video, in order to achieve the goal of controlling myopia, obesity and depression symptoms.

Objective: To investigate the comorbidity of screening myopia and scoliosis among primary and secondary school students in Beijing from 2019 to 2022 and its influencing factors, in order to provide new ideas for comprehensive prevention and control of myopia and scoliosis in children and adolescents. Methods: From 2019 to 2022, 34 923, 34 321, 36 008 and 35 598 primary and secondary school students in Beijing were selected by stratified cluster random sampling method, and visual acuity examination, scoliosis examination and questionnaire survey were conducted on them. Chisquare test was used to analyze the intergroup differences between screening myopia and scoliosis among primary and secondary school students, and the correlation factors between screening myopia and scoliosis were analyzed by multivariate Logistic regression. Results: From 2019 to 2022, the prevalence of screening myopia increased by year,while scoliosis decreased by year, and the comorbidity rate in 2022 (0.69%) decreased by 1.62% compared with 2019 (2.31%). In 2022, screening myopia with scoliosis rates (0.98%) than urban suburbs (0.50%), high school students (1.65%) >professional high school students (1.21%) >junior middle school students (0.76%) >primary school students (0.22%) (χ2=28.97, 153.55, P<0.01). The results of multivariate Logistic analysis found that insufficient sleep time and parents did not limit the use of electronic screen time were the risk factors for screening myopia and scoliosis [OR(95%CI)=1.59(1.20-2.12), 1.34(1.02-1.76), P<0.05]. Teachers often or always remind that reading and writing posture and one hour or more of moderateintensity physical activity every day were protective factors for screening myopia and scoliosis [OR(95%CI)=0.70(0.52-0.96), 0.56(0.34-0.92), P<0.05]. Conclusions The comorbidity of acadmic screening myopia and scdiosis is not optimistic in Beijing. Attention should be paid to the reading and writing posture and related behavioral habits of children and adolescents, and ensure that children in each school section have sufficient sleep time, so as to prevent the occurrence and development of screening myopia and scoliosis.

Objective: To study the correlation between electronic screen use and myopia among primary and secondary school students in six provinces and cities in China, in order to provide a scientific basis for comprehensive prevention and control of myopia. Methods: From November 2020 to June 2022, a total of 16 557 primary and secondary school students from six provinces and cities in China (Beijing City, Liaoning Province, Zhejiang Province, Henan Province, Shaanxi Province, Chongqing City) were selected by stratified cluster random sampling and probability smampling methods, and a questionnaire prepared by Beijing Center for Disease Control and Prevention was used to investigate their electronic screen use. According to Screening Criteria for Myopia in Children and Adolescents, 0.5% mass concentration of compound topicamide eye drops was used to paralyze the ciliary muscle and undergo slit lamp optometry. Chisquare test was used to compare the differences between groups, and binary Logistic regression was used to analyze the association between electronic screen use and myopia. Results: About 58.3% of primary and secondary school students used electronic screens for more than two hours a day on average, and 63.4% of primary and secondary school students used continuously electronic products for more than 15 minutes at a time for nonstudy purposes. After adjusting for confounding factors, parents unrestricted use of electronic screen time and electronic screen time ≥2 h/d were positively correlated with myopia (OR=1.27, 1.13, P<0.05). Gender stratified analysis showed that boys who used electronic screen time ≥2 h/d had a higher risk of myopia (OR=1.15, P<0.05). The results of grade stratification analysis showed that parents unrestricted electronic screen use time and electronic screen time ≥2 h/d were positively correlated with myopia in the lower grade of primary school students (OR=1.34, 1.18, P<0.05). Among the higher grade of primary school students, continuous use of electronic screens for nonstudy purposes for more than 15 minutes at one time was positively correlated with myopia (OR=1.18, P<0.05). There was a multiplicative interaction between total screen time and one continuous screen time (OR=1.04, P<0.05). Conclusions Primary and secondary students in six provinces and cities in China reports excessive electronic screen usage which is associated with myopia. Schools and parents should jointly limit the use of electronic screen among primary and secondary students to reduce the occurrence of myopia.

Objective:To evaluate the quality and item characteristics of the Brief Job Stress Questionnaire (BJSQ) among employees in manufacturing and service industries.Methods:From December 2021 to December 2022, a total of 2077 employees from 4 manufacturing and service enterprises in Beijing were selected by the method of combining purpose sampling and convenience sampling. The Chinese version of BJSQ was used to carry out a survey on occupational stress from 57 items in 4 dimensions including job stress factors, stress response, social support factors and satisfaction. Classical test theory (CTT) was used to analyze the validity and reliability of the questionnaire. The Semejima hierarchical response model in item response theory (IRT) was used to analyze the differentiation a, difficulty coefficient b and information content of each item.Results:Among the 2077 subjects, the age M ( Q1, Q3) was 33 (28, 37) years old, and the working age M ( Q1, Q3) was 4 (2, 8) years. There were 723 (34.8%) people in manufacturing industry and 1354 (65.2%) people in service industry. Eleven common factors were extracted by exploratory factor analysis, with a cumulative variance contribution rate of 62.823%, the variance of the common factors of each entry ranging from 0.451 to 0.865, and the range of factor loading values from 0.413 to 0.825, with 5 items having cross-loadings. The results of the validation factor analysis showed that the model fit indexes of root means square error of approximation was 0.055, comparative fit index was 0.950, Tucker Lewis index was 0.948, and standardized root mean square was 0.066. Content validity results showed that the total scores of the Chinese version of the BJSQ were positively correlated with the scores of the 4 dimensions ( rs=0.487-0.936, P<0.05) . The results of the reliability analysis showed that the Cronbach's alpha coefficient for the total questionnaire was 0.945, and the Cronbach's alpha coefficients of job stress factors, stress response and social support factors were 0.775, 0.957, and 0.830, respectively. The Spearman-Brown coefficient for the total questionnaire was 0.866, and for the 3 dimensions, it was 0.572, 0.882 and 0.772. The results of IRT analysis showed that only 1 of the 57 items had a differentiation a-value<0.30, the difficulty coefficient b-value of each item ranged from -12.02 to 11.09, of which 8 items had a difficulty coefficient that was too high, 3 items had a difficulty coefficient that was too low, and 3 items did not meet the requirements, and the average amount of information in each item ranged from 0.022 to 2.566, and there were 47 items with average amount of information>0.088 (5/57) . Conclusion:The Chinese version of BJSQ has good reliability and validity in the typical occupational groups of manufacturing and service industries in China, and most of the items have good performance, but some items still need to be further improved and optimized or deleted.

Objective:To analyze the current situation and influencing factors of work-related musculoskeletal disorders (WMSDs) among scientific researchers in a computer workstation of a high-tech aerospace enterprise, and to provide data support for the improvement of occupational health management policies in this type of enterprise.Methods:From March to April 2023, using convenient sampling method, 1398 scientific researchers using computer workstations in an aerospace high-tech enterprise in Beijing were selected as the research subjects. The incidence of WMSDs in various parts of the body was investigated by using the Musculoskeletal Disorders Questionnaire, and the influencing factors of WMSDs in neck, lower back, shoulder and upper back were analyzed by logistic regression.Results:The total incidence of WMSDs was 55.4% (774/1398) in the scientific researchers who used computer workstations. The top 4 body parts in WMSDs incidence were neck (24.3%, 340/1398), lower back (20.4%, 285/1398), shoulder (18.7%, 262/1398), upper back (12.7%, 177/1398). The results of multivariate logistic regression analysis showed that feeling slightly tired and tired after work, setting a rest/break time of 10 to 15 min before the next continuous job, and operating computer for 2 to 4 hours and >4 hours were the influencing factors for the occurrence of neck WMSDs ( OR=3.08, 1.90, 0.60, 2.00, 1.49, P<0.05). Female, 5-<10 years of working experience, feeling slightly tired, tired and very tired after work, operating computer for 6-<8 hours and 8-10 hours a day were all the influencing factors for the occurrence of WMSDs in the lower back ( OR=1.82, 0.64, 2.95, 1.80, 1.61, 1.82, 1.73, P<0.05). Female, feeling slightly tired and tired after work were the influencing factors of shoulder WMSDs occurrence ( OR=2.42, 2.09, 2.00, P<0.05). Female, 5-<10 years, 10-15 years of working age, 1-3 times of physical exercise/quarter, feeling slightly tired, tired and very tired after work were the influencing factors for the occurrence of upper back WMSDs ( OR=2.76, 2.19, 2.78, 0.48, 4.20, 2.66, 2.19, P<0.05) . Conclusion:The incidence of WMSDs among scientific researchers in computer workstations of aerospace high-tech enterprises is high, which is closely related to individual characteristics and workstation usage characteristics. Measures should be taken to prevent and improve the WMSDs status of scientific researchers.