Background The prevalence of low back pain among workers using vibrating tools in the automobile manufacturing industry is high; however, research on associated risk factors remains limited. Objective To investigate the association between use of vibrating tools and low back pain among automobile manufacturing workers, and to estimate related population attributable risk percentage (PAR%). Methods A cross-sectional survey was conducted using the Chinese Musculoskeletal Disorders Questionnaire among workers with over one year of service in an automobile manufacturing enterprise. Workers were categorized into an exposed group (vibrating tool users) and a control group (non-users) based on their use of vibrating tools during work. The variables showing statistically significant differences between the two groups were selected as covariates for matching by 1∶2 nearest-neighbor propensity score. Chi-square test was used to compare the prevalence of low back pain between the matched exposed and control groups. Log-binomial regression model was employed to calculate the prevalence ratio (PR), and the PAR% of low back pain attributable to vibrating tool use was subsequently determined. Results A total of 6973 valid questionnaires were collected, comprising 5676 males and 1297 females, with an overall low back pain prevalence of 40.3% (2809/6973). The exposed group included 1255 workers (1134 males, 121 females), with a mean age of (44.2 ± 8.7) years and a mean tenure in the current position of (23.5 ± 9.9) years; the matching control group consisted of 2510 workers (2279 males, 231 females), with a mean age of (44.7 ± 8.6) years and a mean tenure in the current position of (24.0 ± 10.0) years. The prevalence of low back pain was 76.7% (963/1255) in the exposed group, significantly higher than the 29.9% (750/2510) in the control group (P<0.001). The log-binomial regression analysis showed a PR of 2.57 (95%CI: 2.28, 2.90) for the exposed group, with a PAR% of 22.03%. Conclusion The use of vibrating tools among automobile manufacturing workers is positively associated with reporting low back pain. Implementing effective measures to mitigate vibration hazards is crucial for reducing the burden of low back pain in this population.

AIM: To observe the effect of RBC preservation solution with sodium pyruvate on the morphology, structure and function of RBC stored in vitro in type 2 diabetes rats. METHODS: Thirty SPF male SD rats, were randomly divided into 3 groups (n=10): non-T2DM conventional RBC preservation solution (group A), T2DM conventional RBC preservation solution (group B) and T2DM sodium pyruvate RBC preservation solution (group C). The leukoreduced RBC from the tail vein and stored for 0 d (T0), 7 d (T1), 14 d (T2), 21 d (T3) and 28 d (T4) to detect the morphology, structure and the contents of 2, 3-DPG, reactive oxygen species (ROS), malondialdehyde (MDA) and lactic acid (LA) of RBC in group A, B and C. The RBC stored for 14 days in vitro were labeled with PKH26, and its survival rate were tested in vivo at 1, 4, 10 and 16 hours after intravenous infusion. RESULTS: At T0, the RBC morphology of group A was intact, which was better than that of group B and group C. With the extension of storage time, the morphology of RBC in each group gradually transformed into a spindle-spherical shape. Compared with group A, the incidence of acanthocytes in group B and group C was higher, and the incidence of acanthocytes in group C was lower than that in group B. Compared with group A, the content of 2, 3-DPG in group B and group C decreased, while ROS and MDA increased at different time points (P<0.05). The content of 2,3-DPG in group C was higher than that in group B (P<0.05), and the contents of ROS and MDA were lower than those in group B (P<0.05). LA content in group B was higher than that in group A and group C (P<0.05). At T2-T4, the LA content in group C was lower than that in group A (P<0.05). The survival rate of RBC in group A was higher than that in group B and C, and the survival rate of RBC in group B was lower than that in group C (P<0.05). CONCLUSION: Sodium pyruvate added RBC preservation solution has a certain protective effect on RBC stored in vitro in type 2 diabetic rats, and its mechanism may be related to its antioxidant effect.

ObjectiveTo explore the effect of occupational stress on work-related musculoskeletal disorders (WMSDs) in electronics manufacturing workers. Methods A total of 392 front-line workers in two electronic manufacturing enterprises in Guangdong Province were selected as the research subjects using the judgment sampling method. The prevalence of WMSDs and the level of occupational stress of the research subjects were investigated using the Musculoskeletal Disorders Questionnaire and the Core Occupational Stress Scale. Results The total WMSDs detection rate was 39.5%, and the multi-site WMSDs detection rate was 30.6%. The detection rate of occupational stress was 14.8%. The total WMSDs detection rate and multi-site WMSDs detection rate in the occupational stress group were higher than those in the non-occupational stress group (65.5% vs 35.0%, 56.9% vs 26.0%, both P<0.01). Binary logistic regression analysis result showed that the risk of WMSDs in the occupational stress group was higher than that in the non-occupational stress group after adjusting the effect of confounding factors such as age, gender, job type and work days per week (P<0.01). Conclusion The occupational stress may increase the risk of WMSDs in electronics manufacturing workers. Reducing the level of occupational stress among workers in electronic manufacturing enterprises is beneficial for reducing the risk of WMSDs.

Objective:To evaluate the effect of novel erythrocyte preservation solution on the quality of erythrocytes in stored blood of type 2 diabetes mellitus (T2DM) rats.Methods:Forty SPF male Sprague-Dawley rats, aged 8 weeks, weighing 180-220 g, were used in this study. Ten rats randomly selected served as conventional erythrocyte preservation solution group (group A). T2DM model was prepared in the remaining 30 rats. Twenty T2DM rats were divided into 2 groups ( n=10 each) using a random number table method: T2DM conventional erythrocyte preservation solution control group (group C) and T2DM novel erythrocyte preservation solution observation group (group Y). Erythrocyte preservation solution was prepared to simulate the preoperative autologous blood donation process, and blood was collected from the tail vein to isolate the red blood cells, and then the corresponding preservation solution was added. Immediately after blood collection (T 0) and at 7, 14 and 21 days of preservation (T 1-3), the morphological structure of erythrocytes was observed with a light microscope, and the concentrations of 2, 3-diphosphoglycerate (2, 3-DPG) and reactive oxygen species (ROS) were also determined by enzyme-linked immunosorbent assay at T 0-T 3 and 28 days of preservation (T 4). PKH26 was used to label the erythrocytes stored in vitro for 28 days, and then the erythrocytes were transfused back into rats. The survival rate of erythrocytes was detected by flow cytometry at 1, 7, 13 and 18 h after retransfusion. Results:The erythrocyte damage was aggravated at different time points of preservation in group C when compared with group A. Compared with group C, the damage to erythrocytes was significantly alleviated at different time points of preservation in group Y. Compared with group A, the concentration of 2, 3-DPG in erythrocytes was significantly decreased at T 0 and T 2-T 4, the concentration of ROS was increased at T 0-T 4, and the survival rate of erythrocytes was decreased at 1, 7 and 18 h after retransfusion in group C ( P<0.05). Compared with group C, the concentration of 2, 3-DPG in erythrocytes was significantly increased at T 0-T 4, the content of ROS was decreased at T 1, T 3 and T 4, and the survival rate of erythrocytes was increased at 1, 7 and 18 h after retransfusion in group Y ( P<0.05). Conclusions:The novel erythrocyte preservation solution can improve the quality of stored erythrocytes and increase the survival rate of erythrocytes in vivo after retransfusion in T2DM rats.

ObjectiveTo observe the effectiveness and safety of the Chinese herbal medicine Mingshi Granules （明视方颗粒） for low myopia in children with heart yang insufficiency. MethodsA multicentre， prospective， double-blind randomised controlled study was conducted， in which 290 children with low myopia from 8 centres were randomly divided into 145 cases in the treatment group and 145 cases in the control group， and the treatment group was given education， dispensing glasses， and Chinese herbal medicine Mingshi Granules， while the control group was given education， dispensing glasses， and granules placebo. Both Mingshi Granules and placebo granules were taken orally， 1 bag each time， twice daily， 4 weeks of oral intake and 2 weeks of rest as 1 course of treatment， a total of 4 courses of treatment （24 weeks）. Equivalent spherical lenses， best naked-eye distance visual acuity， ocular axis， corneal curvature K1， adjustment amplitude， traditional Chinese medicine （TCM） symptom scores， calculate the amount of progression of equivalent spherical lenses， were observed at the 12th and the 24th week of treatment， at the 36th week and 48th week of follow-up， resectively， the control rate of myopia progression was evaluated at the 24th week， and safety indexes were observed before treatment. ResultsThe amount of progression of equivalent spherical lenses was lower in the treatment group than in the control group at the 48-week follow-up （P＜0.05）. The control rate of myopia progression at 24 weeks after treatment in the treatment group was higher （57.60%， 72/125） than that in the control group （44.63%， 54/121） （P＜0.05）. The best naked-eye distance visual acuity at 36-week follow-up in the treatment group was higher than that in the control group （P＜0.05）. Equivalent spherical lenses were significantly lower in both groups at all observation time points compared with pre-treatment （P＜0.05）， and were higher in the treatment group than in the control group at the 48-week follow-up （P＜0.05）. The ocular axes of both groups were significantly higher at each observation time point after treatment and at follow-up compared with before treatment （P＜0.05）. The amount of eye axis growth in the treatment group was lower than that in the control group at 24 weeks after treatment and at the 48-week follow-up （P＜0.05）. Corneal curvature K1 was significantly lower in the treatment group at the 24th week of treatment compared to pre-treatment （P＜0.05）. The magnitude of adjustment in the treatment group was significantly higher at the 36-week follow-up and at the 48-week follow-up than before treatment （P＜0.05）. The scores of white/dark complexion， white coating thin pulse， fatigue and total TCM symptom scores of children in both groups at the 12th， 24th， 36th and 48th weeks of follow-up were significantly lower than those before treatment （P＜0.05）； the scores of blurred vision at the 24th and 36th weeks of follow-up were significantly lower than those before treatment （P＜0.05）； and the scores of blurred vision in the treatment group at the 48th week of follow-up were signi-ficantly lower than those before treatment （P＜0.05）. In the treatment group， the score of fatigue was higher than that of the control group at the 36-week follow-up， and the score of blurred vision was lower than that of the control group at the 48-week follow-up （P＜0.05）. No adverse reactions or obvious abnormalities of the safety indexes were observed of the two groups during the treatment. ConclusionChinese herbal medicine Mingshi Granules showed the effect of controlling the progression of low myopia， improving the best naked eye distance visual acuity， slowing down the growth of the eye axis， improving some of the TCM symptoms， with good safety.

Objective To explore the correlation between polycystic ovary syndrome(PCOS)and periodontitis in light of cytokines levels,sex hormone levels and metabolism-related indicators and their changes during progression of the two diseases.Methods Twenty healthy subjects and 40 patients diagnosed with PCOS underwent full-mouth periodontal examinations to obtain full-mouth plaque score(FMPS),gingival bleeding index of probing(BOP),probing depth(PD),and clinical attachment level(CAL).The participants were divided into Group A without periodontitis or PCOS(n=15),Group B with PCOS but without periodontitis(n=28),Group C with periodontitis but without PCOS(n=5),and Group D with both diseases(n=12).Serum levels of luteinizing hormone/follicle stimulating hormone(LH/FSH),testosterone,prolactin,progesterone and estradiol,and the levels of interleukin 6(IL-6),IL-17A,tumor necrosis factor α and matrix metalloproteinase 8(MMP-8)in both serum and saliva samples were measured at the time of enrolment and at 3 and 6 months after enrolment and compared among the 4 groups.Results Serum MMP-8 level was significantly higher in Group B than in Group A(P<0.05).Salivary MMP-8 level was significantly higher in Group D than in Group B(P<0.05).Salivary MMP-8,LH,and LH/FSH levels and serum and salivary IL-6 and progesterone levels all tended to increase in the 6 months after enrollment(OR>1,P<0.05).During the follow-up period,serum IL-6 levels differed significantly between the non-PCOS groups(A and C)and PCOS groups(B and D)(P<0.05);serum IL-6 and salivary MMP-8 levels differed significantly between the non-periodontitis groups(A and B)and periodontitis groups(C and D)(P<0.05).Spearman correlation analysis indicated positive correlations of LH and LH/FSH with PD(P<0.05);testosterone and LH/FSH were positively correlated with serum MMP-8 levels(P<0.05),and PD,BOP and FMPS were positively correlated with salivary MMP-8 levels(P<0.01).Conclusion There is a correlation between PCOS and periodontitis,and their progression is accompanied by changes in serum and salivary levels of pro-inflammatory cytokines and serum sex hormones.

Objective:To investigate the clinical value of left ventricular shape index (SI) and eccentricity index (EI) in evaluating left ventricular remodeling.Methods:A retrospective analysis was performed on 324 patients (264 males, 60 females, age (62.5±11.8) years) diagnosed with myocardial infarction (MI) and 113 healthy controls (HC; 47 males, 66 females, age (57.8±10.7) years) who received gated myocardial perfusion imaging (GMPI) in First Hospital of Shanxi Medical University from January 2016 to September 2020. SI (end-diastolic SI (EDSI), end-systolic SI (ESSI)), EI and left ventricular function parameters (end-diastolic volume (EDV), end-systolic volume (ESV), left ventricular ejection fraction (LVEF), summed motion score (SMS), summed thickening score (STS), peak ejection rate (PER) and peak filling rate (PFR)) were obtained by quantitative gated SPECT (QGS) software. Propensity score (PS) inverse probability of treatment weighting (IPTW) was used to balance the intergroup covariates. The differences and correlations of EDSI, ESSI, EI and left ventricular function parameters between patients in MI group and HC group were analyzed. ROC curve analysis was used to evaluate the values of EDV, EDSI, ESSI and EI alone and in combination in the assessment of left ventricular systolic function impairment. Data were analyzed by independent-sample t test, Pearson correlation and Spearman rank correlation analyses, and Delong test. Results:After IPTW, EDSI and ESSI in MI group ( n=319) were higher than those in HC group ( n=133; EDSI: 0.66±0.09 vs 0.60±0.06; ESSI: 0.59±0.11 vs 0.47±0.07; t values: 8.05, 14.67, both P<0.001), and EI was lower than that in HC group (0.81±0.06 vs 0.85±0.03; t=-8.93, P<0.001). In both groups, there were significant correlations between EDSI and ESSI ( r values: 0.928, 0.873), between EDSI, ESSI and EI ( r values: from -0.831 to -0.641), between EDSI, ESSI and LVEF ( r values: from -0.627 to -0.201), between ESSI and EDV, ESV and SMS ( rs values: 0.336-0.584), between ESSI and -PER, PFR ( rs values: from -0.406 to -0.402, r values: from -0.352 to -0.325) (all P<0.01). ROC curve analysis showed that EDV (AUC: 0.895) and ESSI (AUC: 0.839) had the highest efficacy in evaluating left ventricular systolic function impairment in MI group and HC group, respectively. EDV-EDSI-ESSI-(1-EI) had higher efficacy in the assessment of impaired left ventricular systolic function in MI group (AUC: 0.956), which was higher than that of EDV or EDV-EDSI or EDV-ESSI or EDV-(1-EI) ( z values: from -2.64 to -2.18, P values: 0.008-0.029); EDV-EDSI-ESSI-(1-EI) also had high efficacy in HC group (AUC: 0.911), which was higher than that of EDV or EDV-EDSI or EDV-(1-EI) ( z values: from -2.60 to -2.43, P values: 0.009-0.015). Conclusions:In MI patients, the increase of SI and the decrease of EI indicate the increase of left ventricular sphericity and the aggravation of left ventricular remodeling. SI and EI have certain clinical application values in evaluating left ventricular morphology, predicting left ventricular remodeling and left ventricular systolic function impairment.

Background The high-quality development of manufacturing in China has spurred industrial transformation and upgrading, placing higher demands on the skills of employees in the electronic manufacturing industry. This situation may induce psychological health problems such as job burnout and depressive symptoms in the employees, and also lead to insomnia, which has become a public health problem that urgently needs attention and solution. Objective To investigate the relationship between job burnout, depressive symptoms, and insomnia among employees in the electronic manufacturing industry. Methods A total of 3034 employees from four electronic manufacturing companies in Beijing City, Shanghai City, and Guangdong Province were selected using judgment sampling from September to November 2019. The Maslach Burnout Inventory-General Survey, Patient Health Questionnaire-9, and Self-Administered Sleep Questionnaire were used to collect data. The correlation between job burnout, depressive symptoms, and insomnia was evaluated by hierarchical regression. Results A total of 3034 survey questionnaires were distributed, and 2614 valid questionnaires were collected, with a response effectiveness rate of 86.2%. The reporting rates of job burnout, depressive symptoms, and insomnia among employees in the electronic manufacturing industry were 47.2%, 19.5%, and 29.1%, respectively. The reporting rates of insomnia of employees in the job burnout group and depressive symptoms group were higher than those in the non-job burnout group and non-depressive symptoms group (35.3% vs. 23.6%, 47.2% vs. 24.7%, P＜0.001). The results of hierarchical regression showed that job burnout explained 2.8% of the variation of insomnia (P<0.001), and the inclusion of depressive symptoms explained 1.2% of the variation of insomnia (P<0.001). Conclusion Job burnout and depressive symptoms could both affect insomnia of employees in the electronic manufacturing industry.

Objective:To construct a new thrombus risk assessment model and evaluate its predictive ability for venous thromboembolism(VTE)in the patients with malignant tumors,and to provide the basis for the early predition of the malignant tumor patients with high risk for VTE.Methods:A total of 128 untreated malignant tumor patients were included,of which 40 were diagnosed with VTE within 2 months of malignant tumor diagnosis and categorized as VTE group.A total of 88 patients who did not develop VTE were categorized as non-VTE group.The clinical risk factors and laboratory indicators of the patients in two groups were compared and analyzed;the types of thrombotic events of the patients were analyzed;the diagnostic values of thrombin-antithrombin-complex(TAT),α2-plasmin inhibitor-plasmin complex(PIC),D-dimer(D-dimer),and fibrin degradation products(FDP)in malignant tumors complicated by VTE were assessed using receiver operating characteristic(ROC)curve analysis;Multivariate Logistic regression analysis was used to analyze the correlations of the clinical risk factors and biomarkers with the malignant tumors complicated with VTE.A new thrombus risk assessment model was constructed,consisting of TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors.The predictive probability of the model for malignant tumors complicated by VTE was evaluated based on the significance,goodness of fit,calibration curve,and C value of the model.The clinical application value of the new thrombus risk assessment model,COMPASS-CAT risk score(CRS),and Khorana risk score(KRS)in assessing malignant tumor patients complicated by VTE was compared using the C value and decision curve analysis(DCA).Results:The plasma levels of TAT(P＜0.001),PIC(P＜0.001),D-dimer(P＜0.05),and FDP(P＜0.01)of the patients in VTE group were higher than those in non-VTE group.Compared with the patients without cardiovascular risk factors,poor differentiation,and lymphatic metastasis,the malignant tumor patients with cardiovascular risk factors(P＜0.001),poor differentiation(P＜0.001),and lymphatic metastasis(P＜0.05)were more likely to develop VTE.Most VTE events(65％)were isolated deep vein thromboembolism(DVT).The ROC curve analysis showed that the area under the curve(AUC),sensitivity,and specificity of TAT and PIC were higher than those of D-dimer and FDP.TAT≥0.70 μg·L-1(P＜0.05),poor differentiation(P＜0.01),and cardiovascular risk factors(P＜0.01)were the independent risk factors for VTE in the malignant tumor patients.A new thrombus risk assessment model consisting of TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors was constructed.The new risk assessment model had a high goodness of fit(P=0.805)and good predictive ability during internal validation(x2=75.266,P＜0.001).The ROC curve analysis results showed that the C values for the new thrombus risk prediction model,CRS,and KRS were 0.908,0.676,and 0.541,respectively.The DCA curve analysis results showed that the new thrombus risk assessment model had a higher net benefit rate compared with CRS and KRS.Conclusion:TAT and PIC have greater diagnostic efficiency than D-dimer in the early prediction of the malignant tumor patients with high-risk VTE.For the patients included in this study,the new thrombus risk assessment model,constructed from TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors,has superior diagnostic efficiency and clinical predictive value compared with CRS and KRS.

Objective To explore the correlation between polycystic ovary syndrome(PCOS)and periodontitis in light of cytokines levels,sex hormone levels and metabolism-related indicators and their changes during progression of the two diseases.Methods Twenty healthy subjects and 40 patients diagnosed with PCOS underwent full-mouth periodontal examinations to obtain full-mouth plaque score(FMPS),gingival bleeding index of probing(BOP),probing depth(PD),and clinical attachment level(CAL).The participants were divided into Group A without periodontitis or PCOS(n=15),Group B with PCOS but without periodontitis(n=28),Group C with periodontitis but without PCOS(n=5),and Group D with both diseases(n=12).Serum levels of luteinizing hormone/follicle stimulating hormone(LH/FSH),testosterone,prolactin,progesterone and estradiol,and the levels of interleukin 6(IL-6),IL-17A,tumor necrosis factor α and matrix metalloproteinase 8(MMP-8)in both serum and saliva samples were measured at the time of enrolment and at 3 and 6 months after enrolment and compared among the 4 groups.Results Serum MMP-8 level was significantly higher in Group B than in Group A(P<0.05).Salivary MMP-8 level was significantly higher in Group D than in Group B(P<0.05).Salivary MMP-8,LH,and LH/FSH levels and serum and salivary IL-6 and progesterone levels all tended to increase in the 6 months after enrollment(OR>1,P<0.05).During the follow-up period,serum IL-6 levels differed significantly between the non-PCOS groups(A and C)and PCOS groups(B and D)(P<0.05);serum IL-6 and salivary MMP-8 levels differed significantly between the non-periodontitis groups(A and B)and periodontitis groups(C and D)(P<0.05).Spearman correlation analysis indicated positive correlations of LH and LH/FSH with PD(P<0.05);testosterone and LH/FSH were positively correlated with serum MMP-8 levels(P<0.05),and PD,BOP and FMPS were positively correlated with salivary MMP-8 levels(P<0.01).Conclusion There is a correlation between PCOS and periodontitis,and their progression is accompanied by changes in serum and salivary levels of pro-inflammatory cytokines and serum sex hormones.