Background Occupational stress has emerged as a critical public health concern affecting the physical and mental well-being of workers in the manufacturing sector. However, researchers typically evaluate its core driver—cumulative fatigue—using a crude binary “present/absent” variable, thereby overlooking the high-dimensional complexity and heterogeneity inherent in fatigue characteristics. This oversimplification constrains both the precision and predictive performance of occupational stress risk assessment model. Objective Leveraging a data-driven approach, to survey data on cumulative fatigue among manufacturing employees, and then use this new classification to develop and validate an occupational stress prediction model, with an ultimate aim of enhancing the accuracy and effectiveness of occupational stress assessment. Methods A set of cross-sectional survey data on 3871 manufacturing employees in 2021 were derived from the “Long working hours exposure and its adverse health effect risk assessment” program of the National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention. Occupational stress was assessed using the Core Occupational Stress Measurement Scale, while cumulative fatigue was evaluated via the Worker’s Self-Diagnostic Questionnaire for Fatigue Accumulation. Boruta method was applied to screen core variables from 20 occupational stress influencing factors. Dimensionality reduction of cumulative fatigue features was performed using a Bayesian sparse autoencoder (BASE), followed by comparison and application of clustering methods to achieve multi-class classification of the reduced features. Six machine learning classification models were then selected including logistic regression, support vector machine, decision tree, random forest, adaptive boosting, and lightweight gradient boosting machine (LightGBM) to construct and compare two occupational stress prediction models involving cumulative fatigue combined with ten other core variables: one utilizing the original binary cumulative fatigue label as a core variable, and another employing the novel fatigue classification proposed herein as a core variable. Results The positive rate of occupational stress among the manufacturing employees was 38.9%. The Boruta method identified 11 core variables of occupational stress: depressive symptoms, cumulative fatigue, age, length of service, tenure in current position, average weekly working hours, average daily overtime hours, average monthly income, low levels of exercise, life satisfaction, and sleep quality. The BSAE reduced the original cumulative fatigue factors to 12 dimensions, while the K-means clustering grouped the reduced fatigue features into three categories: no fatigue, moderate fatigue, and sever fatigue. Six occupational stress prediction models were constructed using the three-category labels of cumulative fatigue and ten additional factors. The results indicated that the LightGBM model performed best, achieving an area under the curve (AUC) of 0.78, an accuracy of 0.77, and an F1 score of 0.72. Compared with the model incorporating the traditional binary labels for cumulative fatigue, the best prediction AUC (0.72), accuracy (0.66), and F1 score (0.65) improved by 6%, 11%, and 7%, respectively. Conclusion Cumulative fatigue is a significant predictor of occupational stress among manufacturing employees. Applying data dimensionality reduction combined with three-class cluster analysis to characterize cumulative fatigue improves the performance of occupational stress prediction models. From a data-driven perspective, machine learning methods demonstrate strengths in processing complex datasets, capturing nonlinear relationships, and generating predictions based on key variables. This study therefore confirms that refined processing of core factors substantially enhances the predictive capability of machine learning models in assessing occupational stress risk in the manufacturing workforce.

Objective:To explore the prognostic value of BRCA1-associated protein 1 (BAP1) expression loss in patients with malignant mesothelioma (MM) .Methods:A total of 82 MM patients from January 1998 to December 2017 in Zhejiang Province were selected to detect the expression of BAP1 protein by immunohistochemical analysis. Kaplan-Meier method was used to draw the survival curve, and multivariate Cox proportional risk model was used to analyze the factors affecting the survival rate.Results:Among 82 MM patients, 61 (74.4%) were female, aged (57±11) years. BAP1 protein expression was deficient in 39 patients (47.6%). The survival rate was correlated with the loss of BAP1 protein expression and age (χ 2=5.27, 5.66, P=0.022, 0.017). Subgroup analysis showed that loss of BAP1 protein expression was associated with better prognosis in MM patients <57 years of age, female, pleural MM, epithelial MM, and treated with drugs or surgery ( P<0.05). Multivariate model results showed that positive expression of BAP1 protein ( HR=3.75, 95% CI: 2.23-6.30, P<0.001) and age ≥57 years ( HR=1.66, 95% CI: 1.01-2.72, P=0.049) were risk factors for survival in patients with MM. Conclusion:Loss of BAP1 protein expression may be an independent prognostic factor in patients with MM, which is associated with longer survival.

Objective:To explore the prognostic value of BRCA1-associated protein 1 (BAP1) expression loss in patients with malignant mesothelioma (MM) .Methods:A total of 82 MM patients from January 1998 to December 2017 in Zhejiang Province were selected to detect the expression of BAP1 protein by immunohistochemical analysis. Kaplan-Meier method was used to draw the survival curve, and multivariate Cox proportional risk model was used to analyze the factors affecting the survival rate.Results:Among 82 MM patients, 61 (74.4%) were female, aged (57±11) years. BAP1 protein expression was deficient in 39 patients (47.6%). The survival rate was correlated with the loss of BAP1 protein expression and age (χ 2=5.27, 5.66, P=0.022, 0.017). Subgroup analysis showed that loss of BAP1 protein expression was associated with better prognosis in MM patients <57 years of age, female, pleural MM, epithelial MM, and treated with drugs or surgery ( P<0.05). Multivariate model results showed that positive expression of BAP1 protein ( HR=3.75, 95% CI: 2.23-6.30, P<0.001) and age ≥57 years ( HR=1.66, 95% CI: 1.01-2.72, P=0.049) were risk factors for survival in patients with MM. Conclusion:Loss of BAP1 protein expression may be an independent prognostic factor in patients with MM, which is associated with longer survival.

Objective To isolate and culture neural crest cells(NCCs)from lung tissue of mice and to identify the characteristics of the cells in order to provide a new cell model for studying lung injury and injure repair.Methods The mT/mG dual-fluorescence reporter mice and Wnt1-Cre transgenic mice were hybridized,and mT/mG;Wnt1-Cre transgenic mice were screened to obtain enhanced green fluorescent protein(EGFP)permanently labeled NCCs.Cell suspension of mouse lung tissue was prepared by enzymolysis.EGFP+cells(namely NCCs)were har-vested by flow cytometry.Primary culture was performed with DMEM/F12 culture medium optimized in the labora-tory,NCCs was characterized by immunofluorescence microscopy.Then NCCs differentiation was directed by mouse bone marrow mesenchymal stem cells osteogenic induction.Results The mT/mG of EGFP permanently labeled NCCs was successfully obtained by hybridization and high-purity NCCs were isolated from Wnt1-Cre transgenic mice lung tissue.They can be cultured in vitro and with spindle morphology which was,similar to fibroblast adherent proliferation.NCCs expressed the neural crest stem cell marker Sox10 and induced to differentiate into osteoblasts.Conclusions NCCs isolated and cultured from lung tissue of mT/mG;Wnt1-Cre transgenic mice show stable prolif-eration and have the characteristics of neural crest stem cells,which may function as a potential cell model for re-search on lung tissue injury and the mechanism of repair.

Objective: To analyze the semen quality parameters of sperm donor volunteers, so as to provide insights into male infertility control and related research. Methods: A total of 155 sperm donors were recruited from the Human Sperm Bank of Zhejiang Province using the convenience sampling method from January to March 2021. Demographic information were collected through questionnaire surveys. Semen were collected, and parameters including semen volume, sperm concentration, total number of sperm, forward motility rate and total sperm viability were measured. Semen quality was evaluated according to the WHO Laboratory Manual for the Examination and Processing of Human Semen. : Results Conclusion There were 20.65% of the 155 sperm donors with unqualified semen, and the unqualified rates of forward motility rate and total sperm viability were relatively high.

Objective: To explore the changes in ribosomal DNA copy number in peripheral blood among patients with pneumoconiosis and its influencing factors, so as to provide insights into prevention and treatment of pneumoconiosis. Methods: Eighty-eight patients with pneumoconiosis who visited a designated hospital and 71 community residents with no history of pneumoconiosis or dust exposure were selected as the pneumoconiosis group and control group, and age, smoking history, drinking history and cumulative years of exposure to dust were collected through questionnaire surveys. The copy number of 45S rDNA and 5S rDNA was detected using real-time fluorescence quantitative PCR, and the differences between the two groups were compared. Factors affecting the copy number of 45S rDNA and 5S rDNA were identified by a multiple linear regression model. Results: The pneumoconiosis group had a median age of 56.00 (interquartile range, 15.25) and a mean cumulative dust exposure duration of (12.40±8.08) years, with 56.82% smoking and 62.50% drinking. The control group had a median age of 64.00 (interquartile range, 37.00) years, with 32.39% smoking and 26.76% drinking. The median copy number of 45S rDNA in the pneumoconiosis group was 1.29 (interquartile range, 0.59), which was lower than 2.10 (interquartile range, 1.88) in the control group; the median copy number of 5S rDNA in the pneumoconiosis group was 5.33 (interquartile range, 0.85), which was higher than 4.66 (1.34) in the control group (both P<0.05). Multiple linear regression analysis identified age (β=-0.034) and pneumoconiosis (β=-1.595) as factors affecting 45S rDNA copy number, age (β=-0.013) as a factor affecting 5S rDNA copy number, and age (β=0.018) as a factor affecting 5S rDNA copy number in the pneumoconiosis group (all P<0.05). Conclusions Compared with community residents with no history of pneumoconiosis or dust exposure, the copy number of 45S rDNA in peripheral blood among patients with pneumoconiosis is reduced and the copy number of 5S rDNA is increased.

Background As one of the common tools for job burnout assessment, Maslach Burnout Inventory-General Survey (MBI-GS), its reliability and validity across different populations in China have not been examined yet. Objective To evaluate the reliability and validity of General Burnout Scale (GBS) by multiple occupational groups through the translation and preliminary test of MBI-GS. Methods Based on the Special Project of Occupational Hazards in Key Populations led by the Institute of Occupational Health and Poison Control, China CDC, key occupational groups in five typical industries were selected by multi-stage stratified cluster sampling, including teachers, firefighters, manufacturing workers, medical staff, and traffic police. Confirmatory factor analysis (CFA) was used to evaluate the construct validity of GBS by single-factor, two-factor, and three-factor structure models. The model fitness was assessed by ratio of the chi-square statistic to the respective degrees of freedom (χ²/ν), root mean square error of approximation (RMSEA), goodness-of-fit index (GFI), comparative fit index (CFI), and parsimony-adjusted non-normed fit index (PNFI). Spearman correlation analysis was used to calculate the criterion validity of GBS with occupational stress, depressive symptoms, and sleep disorders. Cronbach's α coefficient and composite reliability (CR) coefficient were used to evaluate the internal consistency reliability of GBS. Results A total of 3485 subjects were surveyed in this study, 3375 valid questionnaires were recovered with a valid response rate of 96.84%. The results of CFA showed that in the adjusted three-factor structure model of GBS (exhaustion, cynicism, and professional efficacy), the χ²/ν < 4, the RMSEA ranged from 0.032 to 0.069, the GFI > 0.90, the CFI > 0.90, and the PNFI > 0.70, which illustrated a good fitness than that of the single- or the two-factor structure models in different occupational groups. The Spearman correlation analysis results showed that occupational stress, depressive symptoms, and sleep disorders were positively correlated with exhaustion and cynicism dimensions, and negatively correlated with professional efficacy dimension of the GBS, with the \begin{document}$ \left| r \right| $\end{document} ranging from 0.139 to 0.662 (P<0.05) in overall subjects. For traffic police and firefighters, professional efficacy was not correlated with depressive symptoms or sleep disorders (P>0.05). The Cronbach's α coefficients ranged from 0.819 to 0.899, and the CR values ranged from 0.941 to 0.978 in different occupational groups. Conclusion The GBS shows high reliability and validity, as well as good application effects in different occupational groups.

Background With the rise and deepening of positive psychology research, theoretical research on job burnout is also deepening worldwide, and some new theoretical models are proposed, such as the burnout-engagement continuum, but there is still a lack of empirical research and application in China. Objective To analyze the current situation and influencing factors of five profiles in the burnout-engagement continuum in working populations of China: job engagement, ineffective, overextended, disengaged, and burnout. Methods From August to October 2019 and June to September 2020, a total of 27344 subjects of key occupations in six typical industries, including teachers, firefighters, manufacturing workers, medical staff, flight attendants, and traffic police, were selected from 10 provinces (cities) in the eastern, middle, and western regions of China by multistage stratified cluster sampling method for cross-sectional investigation. Maslach Burnout Inventory-General Survey and Core Occupational Stress Scale were used to evaluate job burnout and occupational stress respectively. χ² test was used to compare rates of count data. Binary logistic regression was used for multivariate analysis of the five profiles. Results Among the subjects, 24.4%, 61.9%, 31.9%, 12.7%, and 11.8% were the prevalence rates of job engagement, ineffective, overextended, disengaged, and burnout, respectively. Flight attendants (35.7%), firefighters (29.0%), traffic police (28.5%), and manufacturing workers (26.5%) had high prevalence rates of job engagement profile. Medical stuff (62.9%) and manufacturing workers (61.8%) had high prevalence rates of ineffective profile. Teachers (39.2%), traffic police (37.2%), and medical stuff (35.5%) had high prevalence rates of overextended profile. Traffic police (17.9%), medical staff (14.3%), and teachers (13.4%) had high prevalence rates of disengaged profile. Traffic police (16.9%), medical staff (13.4%), and teachers (13.3%) had high prevalence rates of burnout profile. The results of multivariate analysis showed that gender, age, education level, marital status, weekly working hours, length of service, income per month, shift work, smoking, drinking, industry, and occupational stress entered into the regression equations of job engagement, ineffective, overextended, disengaged, and burnout. The risks of overextended (OR=1.456-2.970), disengaged (OR=1.306-4.092), and burnout (OR=1.302-4.102) among the high rating groups of the four factors of occupational stress were higher than those among the low rating groups. Flight attendants (OR=0.296) and firefighters (OR=0.329) had lower risks of burnout than teachers, and flight attendants (OR=0.392) and firefighters (OR=0.466) had lower risks of disengaged than teachers. Conclusion Among the prevalence rates of the five profiles in the burnout-engagement continuum in the 6 typical occupational populations in China, ineffective profile is the highest, followed by overextended, and burnout is the lowest. Gender, age, education level, marital status, weekly working hours, length of service, income per month, shift work, smoking, drinking, industry, and occupational stress have different effects on the five profiles, but industry and occupational stress have greater impacts on job burnout.

Background Manufacturing industry is the main body of China's national economy, and manufacturing employees provide solid guarantee and support for the vigorous development of China's manufacturing industry. The research on job burnout of manufacturing employees is helpful to prevent or alleviate the health damage and economic loss caused by job burnout. Objective To investigate the status and influencing factors of job burnout among manufacturing employees in China, and evaluate the potential mediating effect of job burnout between job stress and depressive symptoms. Methods A cross-sectional study was performed from August to October 2019 and from June to September 2020 in seven provinces of China. Study participants were recruited from 21 manufacturing companies covering 11 manufacturing subdivisions using multistage stratified cluster sampling. General Burnout Scale, Core Occupational Stress Scale, and Patient Health Questionnaire-9 were used to evaluate job burnout, job stress, and depressive symptoms. Mann-Whitney U test and Kruskal-Wallis H test were used to compare data between two independent samples and multiple independent samples of measurement data; Pearson χ² test was used to compare the rate of enumeration data; Spearman rank correlation analysis was used to evaluate correlation between selected variables; binary logistic regression was used for multivariate analysis; stepwise regression and bias-corrected Bootstrap method were used to test potential mediating effect. Results A total of 10973 valid questionnaires were collected. The M (P₂₅, P₇₅) scores of exhaustions, cynicism, professional efficacy, job burnout, job stress, and depressive symptoms were 1.6 (0.4, 3.0), 1.0 (0.2, 2.2), 4.8 (3.2, 5.7), 1.6 (0.8, 2.5), 45.0 (40.0, 50.0), and 7.0 (4.0, 11.0), respectively. The positive rates of job burnout, job stress, and depressive symptoms were 53.4% (5865/10973), 28.4% (3116/10973), and 29.4% (3231/10973), respectively. The influencing factors of job burnout were gender (versus male; OR for female=0.852), age (versus≤25 years old; ORs for 26-30, 31-40, 41-50, 51-60 years old=0.824, 0.819, 0.738, 0.677), education level (versus junior high school or below; ORs for senior high school/technical secondary school, junior college/vocational college, graduate school or above=1.119, 1.345, 1.331), income per month (versus＜3000 yuan; ORs for 3000-4999, 5000-6999, 7000-8999, 9000-10999, ≥11000 yuan=0.513, 0.470, 0.430, 0.375, 0.411), position (versus assembly line; OR for non-assembly line=0.814), average weekly working hours (versus ≤40 h; ORs for 61-70, ＞70 h=1.199, 1.519), and drinking (versus non-drinking; OR for drinking=1.261). Job burnout was positively correlated with job stress and depressive symptoms (r=0.556, 0.508, P<0.001). Job burnout played a partial mediating role between job stress and depressive symptoms, and its contribution value accounted for 63.2% of the total effect. Conclusion Manufacturing industry employees' job burnout problem is prominent in China, and there are many factors affecting job burnout. Job burnout may play a partial mediating role between job stress and depressive symptoms in the target group.

Objective: To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. : Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio. : Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. Conclusions Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.