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.

Background During urbanization, the passenger load on urban public transport systems continues to increase, exposing bus drivers to a high risk of musculoskeletal disorders (MSDs). This occupational health issue may also potentially compromise public transport safety. Objective To investigate the prevalence of MSDs among bus drivers in a first-tier city and to explore associated influencing factors. Methods A self-administered questionnaire survey was conducted from December 2024 to March 2025 among 1300 bus drivers in a bus company. Data were collected on general demographic information, occupational activities, and MSDs indicators. A total of 1268 valid questionnaires were returned, yielding a response rate of 97.5%. Descriptive statistics were used to analyze the distribution characteristics of MSDs. Pearson χ² tests were employed to examine the association between MSDs prevalence and individual/occupational characteristics. Logistic regression was performed to identify the influencing factors of MSDs. Results The survey revealed that the prevalence of MSDs among the bus drivers was 28.5%, with the highest prevalence in the 41–50 years age group (30.5%). The conditions primarily affected the cervical spine (60.5%) and lumbar spine (61.9%), with some cases involving multiple sites. The logistic regression model indicated that the following factors were associated with a higher risk of MSDs: frequent smoking (OR=1.477), poor or moderate self-reported health status (OR=4.422), 11–20 years of service (OR=1.749), daily cumulative driving time ≥361 min (OR=1.616), frequent whole-body fatigue during driving (OR=2.077), occasional whole-body fatigue during driving (OR=1.873), feeling tense during driving (OR=1.518), fatigue after work (OR=2.485), work-related stress (OR=1.882), and prolonged smartphone use with head-down posture (OR=1.671). Conversely, occasional exercise (OR=0.713)/frequent exercise (OR=0.569), driving intervals ≥21 min per round (OR=0.645), and perceiving the driving seat comfortable (OR=0.429) were associated with a lower risk of MSDs. Conclusion Physical exercise, smoking, years of service, daily cumulative driving time, driving intervals per round, prolonged smartphone use with head-down posture, self-reported health status, and psychological factors such as work-related stress are influencing factors for MSDs among bus drivers. Drivers should increase physical exercise and change unhealthy living habits. Employers should optimize working conditions, arrange reasonable driving schedules, and foster a positive work environment to reduce MSDs prevalence.

Background During urbanization, the passenger load on urban public transport systems continues to increase, exposing bus drivers to a high risk of musculoskeletal disorders (MSDs). This occupational health issue may also potentially compromise public transport safety. Objective To investigate the prevalence of MSDs among bus drivers in a first-tier city and to explore associated influencing factors. Methods A self-administered questionnaire survey was conducted from December 2024 to March 2025 among 1300 bus drivers in a bus company. Data were collected on general demographic information, occupational activities, and MSDs indicators. A total of 1268 valid questionnaires were returned, yielding a response rate of 97.5%. Descriptive statistics were used to analyze the distribution characteristics of MSDs. Pearson χ² tests were employed to examine the association between MSDs prevalence and individual/occupational characteristics. Logistic regression was performed to identify the influencing factors of MSDs. Results The survey revealed that the prevalence of MSDs among the bus drivers was 28.5%, with the highest prevalence in the 41–50 years age group (30.5%). The conditions primarily affected the cervical spine (60.5%) and lumbar spine (61.9%), with some cases involving multiple sites. The logistic regression model indicated that the following factors were associated with a higher risk of MSDs: frequent smoking (OR=1.477), poor or moderate self-reported health status (OR=4.422), 11–20 years of service (OR=1.749), daily cumulative driving time ≥361 min (OR=1.616), frequent whole-body fatigue during driving (OR=2.077), occasional whole-body fatigue during driving (OR=1.873), feeling tense during driving (OR=1.518), fatigue after work (OR=2.485), work-related stress (OR=1.882), and prolonged smartphone use with head-down posture (OR=1.671). Conversely, occasional exercise (OR=0.713)/frequent exercise (OR=0.569), driving intervals ≥21 min per round (OR=0.645), and perceiving the driving seat comfortable (OR=0.429) were associated with a lower risk of MSDs. Conclusion Physical exercise, smoking, years of service, daily cumulative driving time, driving intervals per round, prolonged smartphone use with head-down posture, self-reported health status, and psychological factors such as work-related stress are influencing factors for MSDs among bus drivers. Drivers should increase physical exercise and change unhealthy living habits. Employers should optimize working conditions, arrange reasonable driving schedules, and foster a positive work environment to reduce MSDs prevalence.

Background Bus drivers are a high-risk group for work-related musculoskeletal disorders (WMSDs). There are a large number of bus drivers in mega-cities. High volumes of passenger traffic and complexity of road conditions may elevate their risk of WMSDs, but there are few studies related to this group. Objective To investigate the prevalence of WMSDs among bus drivers in a mega-city and to analyze potential influencing factors. Methods Based on cross-sectional study design and self-administered questionnaire, the prevalence of WMSDs in past 12 months were estimated by stratified cluster sampling among bus drivers in a mega-city. Pearson χ² and logistic regression models were used to analyze the influencing factors for the body regions with a high prevalence. Results The overall prevalence of WMSDs in past 12 months among bus drivers in a mega-city was 49.5% (551/1113). The prevalence of WMSDs by body regions ranged from 4.0% to 38.5%, and led by neck pain (38.5%), lower back pain (25.5%), and shoulder pain (20.8%). The results of logistic regression showed that the risk factors for neck pain were age (>50 years), smoking, tiredness after work (moderate, severe), long sitting (frequently), awkward postures (sometimes, often, frequently), overtime(occasionally, often), workplace temperature (uncomfortable), and noise (severe) (OR=2.014、1.577、2.793、3.025、2.708、2.032、3.406、2.746、1.442、2.998、1.456、3.506；P<0.05); the lower back pain risk factors were current work experience (6-10 years, 11-15 years, and 16-20 years), smoking, tiredness after work (moderate, severe), and awkward postures(sometimes, often, frequently)(OR=1.777、2.130、2.400、1.503、2.951、3.364、1.836、4.569、2.786，P<0.05); and the shoulder pain risk factors were age (46-50 years, and >50 years), smoking, tiredness after work (moderate, severe), vehicle type (hybrid power, diesel oil), awkward postures (often, frequently), overtime (often), and workplace temperature (uncomfortable) (OR=1.737、2.357、1.553、2.259、2.489、1.659、3.295、2.777、3.320、2.266、1.426，P<0.05). Identified protective factors for neck and lower back pain were off-duty physical activity (1-2 times per week, and ≥3 times per week) (OR=0.553、0.470、0.586、0.485，P<0.05). Conclusion Nearly half of the bus drivers in the mega-city report symptoms of WMSDs, mainly in the neck, lower back, and shoulders. The prevalence is related to individual and occupational factors, and prevention and intervention measures should be actively taken.

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 investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

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.