Objective: To investigate the prevalence and risk factors of occupational musculoskeletal disorders among workers in heavy-duty automobile parts factories in Beijing Municipality, so as to provide insights into development of effective interventions for occupational musculoskeletal disorders. Methods: The workers in three heavy-duty automobile truck parts factories in Beijing Municipality were recruited using the convenient sampling method during the period from May 2019 to October 2020. Subjects' demographic characteristics, type of job and prevalence of occupational musculoskeletal disorders at various sites were collected using self-designed electronic questionnaires, and the factors affecting the development of occupational musculoskeletal disorders were identified using a multivariable logistic regression model. Results: A total of 264 workers were enrolled, including 260 males (98.48%) and 4 females (1.52%). The participants had a mean age of (31.71±6.13) years, and mean duration of (7.51±5.25) years at current position, and mechanical technician was the major type of work (129 workers, 48.86%). The prevalence of occupational musculoskeletal disorders was 70.08% among the participants, and high prevalence of occupational musculoskeletal disorders was found in the lower back/waist (41.28%), shoulder (40.15%), neck (39.02%) and upper back (33.33%). Multivariable logistic regression analysis identified females (OR=1.280, 95%CI: 1.021-1.602) and head-down posture at work (OR=2.644, 95%CI: 1.034-6.763) as risk factors for occupational musculoskeletal disorders at neck; females (OR=1.633, 95%CI: 1.624-2.117), sheet metal workers, mechanical technicians and painters (OR: 5.811-10.452, 95%CI: 1.205-54.027), working in an uncomfortable posture (OR：1.376-7.749, 95%CI: 1.034-27.270) and frequent working overtime (OR=2.081, 95%CI: 1.192-4.137) as risk factors for occupational musculoskeletal disorders at shoulder; and sheet metal workers, mechanical technicians and painters (OR: 8.760-11.948, 95%CI: 1.630-66.927), working in an uncomfortable posture (OR：4.067-12.185, 95%CI: 1.332-47.523) and frequent working overtime (OR=2.201, 95%CI: 1.142-4.244) as risk factors for occupational musculoskeletal disorders at waist/back. Conclusions The prevalence of occupational musculoskeletal disorders is high among workers in heavy-duty automobile parts factories, which mainly occur at shoulder, neck, waist and back. Type of work, working posture and working duration are main factors affecting the development of occupational musculoskeletal disorders.

Objective To observe the pharmacokinetics and concentration of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in brain tissue after BCNU-polylactic acid (PLA) delayed release wafer embedded in brain tissues of dogs.Methods 10% BCNU-PLA delayed release wafer were prepared and embedded in brains of 12 dogs. Peripheral blood of dogs was taken and the animals were executed for brain tissue after surgery in different times. BCNU concentrations in blood and brain tissue were quantified by high-performance liquid chromatography.Results BCNU was able to be detected at 22nd hour, and the Cmax (average 243.64 ng/ml) appears at 35th hour after surgery. The average BCNU concentration in brain tissue was 26.60 μg/g at 5th day after surgery.Conclusion BCNU-PLA delayed release wafer is a useful type for treatment of malignant gliocoma.

Objective To investigate the antitumor effect of Haishengsu injection extracted from marine shellfish. Methods Transplant tumor models of sarcoma 180 (S 180), Ehrlich ascites carcinoma (EAC), and hepatoma (Heps) in mice were established. Different doses of Haishengsu injection were given to the mice and the tumor inhibition rates of Haishengsu injection, life span of the mice were calculated. Results The tumor inhibition rates of haishengsu injection (490～1000mg?kg -1?d -1,iv) were 41.10%～49.08% in mice with S 180 and 36.29%～49.19% in mice with hepatoma,respectively. The same doses of Haishengsu injection prolonged the life spans of EAC-bearing mice by 22.93%～69.98%. Conclusion The haishengsu injection has the antitumor effects on the tumor-bearing mice without evident side effects.

Objective:To analyze the detection and influencing factors of work-related musculoskeletal disorders (WMSDs) of workers in an automobile manufacturing enterprise in Guangzhou City.Methods:In April 2020, a total of 7065 workers of an automobile manufacturing enterprise in Guangzhou City were selected as research subjects using cluster sampling method. The Nordic Musculoskeletal Questionnaire (NMQ) was used to investigate the detection of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors of WMSDs.Results:The detection rate of WMSDs was 43.9% (3102/7065) , among which the detection rate of multiple WMSDs was 31.4%. The detection rates of WMSDs in different parts from high to low were as follows: neck (24.5%) , shoulder (21.1%) and ankle (20.1%) . Multivariate logistic regression analysis showed that working experience of 3-8 years, >8 years, age>30 years old, repetitive work every day, multiple repetitions per minute, uncomfortable work posture, frequent overtime work and lack of staff in the department were risk factors for multi-site WMSDs ( P<0.05) . Adequate rest time was a protective factor for multi-site WMSDs ( P<0.05) . Conclusion:The detection rates of WMSDs in neck, shoulder, ankle, and multisite in automobile manufacturing enterprise are relatively high. The primary risk factors include adverse ergonomic factors and unreasonable organization of labour factors, optimize the work breaks can effectively reduce the risk of disease, effective ergonomic interventions should be carried out to prevent the occurrence of WMSDs among workers in the automobile manufacturing industry.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in the cabinet factory workers, and explore the influencing factors of workers' WMSDs.Methods:A cross-sectional survey method was used to investigate the risk factors such as basic conditions, labox dnganiza, ergonomics load and occurrence of WMSDs of 821 workers in a cabinet factory of a furniture manufacturing company in Guangdong Province using the electronic version of the Musculoskeletal Injury Questionnaire from October to December 2019. χ 2 test and logistic regression were used to analyze the risk factors leading to WMSDs. Results:The incidence of WMSDs in cabinet production workers reached 51.5% (423/821) , and the top three incidences were shoulder (28.4%, 233/821) , neck (28.1%, 231/821) , and wrist (25.9%, 213/821) . The incidence of neck WMSDs was statistically significant among different types of work ( P<0.05) . Multiple repetitive operations per minute ( OR=1.70) , torso often maintaining the same posture ( OR=1.61) , turning heads for a long time ( OR=1.58) and frequent heavy lifting ( OR=1.44) were risk factors for the occurrence of shoulder WMSDs ( P<0.05) . Frequent maintenance of the same posture in the neck ( OR=1.91) , repeated operations per minute ( OR=1.87) , shortage of department staff ( OR=1.65) and turning head for a long time ( OR=1.48) were risk factors for the occurrence of neck WMSDs ( P<0.05) . Long-term bending of the wrist ( OR=2.25) , grasping objects tightly ( OR=2.13) , working hard on the upper limbs or hands ( OR=1.91) , shortage of department personnel ( OR=1.84) , repeated operations per minute ( OR=1.68) and the use of vibration tools ( OR=1.51) were risk factors for the occurrence of WMSDs in the wrist ( P<0.05) . Conclusion:The incidence of WMSDs in cabinet factory is relatively high, the occurrence of WMSDs in the shoulders, necks and wrists is more serious. Reasonable labor organization and reducing the load of poor ergonomics in the workplace, can reduce the occurrence of WMSDs in production workers.

Objective:To analyze the detection and influencing factors of work-related musculoskeletal disorders (WMSDs) of workers in an automobile manufacturing enterprise in Guangzhou City.Methods:In April 2020, a total of 7065 workers of an automobile manufacturing enterprise in Guangzhou City were selected as research subjects using cluster sampling method. The Nordic Musculoskeletal Questionnaire (NMQ) was used to investigate the detection of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors of WMSDs.Results:The detection rate of WMSDs was 43.9% (3102/7065) , among which the detection rate of multiple WMSDs was 31.4%. The detection rates of WMSDs in different parts from high to low were as follows: neck (24.5%) , shoulder (21.1%) and ankle (20.1%) . Multivariate logistic regression analysis showed that working experience of 3-8 years, >8 years, age>30 years old, repetitive work every day, multiple repetitions per minute, uncomfortable work posture, frequent overtime work and lack of staff in the department were risk factors for multi-site WMSDs ( P<0.05) . Adequate rest time was a protective factor for multi-site WMSDs ( P<0.05) . Conclusion:The detection rates of WMSDs in neck, shoulder, ankle, and multisite in automobile manufacturing enterprise are relatively high. The primary risk factors include adverse ergonomic factors and unreasonable organization of labour factors, optimize the work breaks can effectively reduce the risk of disease, effective ergonomic interventions should be carried out to prevent the occurrence of WMSDs among workers in the automobile manufacturing industry.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in the cabinet factory workers, and explore the influencing factors of workers' WMSDs.Methods:A cross-sectional survey method was used to investigate the risk factors such as basic conditions, labox dnganiza, ergonomics load and occurrence of WMSDs of 821 workers in a cabinet factory of a furniture manufacturing company in Guangdong Province using the electronic version of the Musculoskeletal Injury Questionnaire from October to December 2019. χ 2 test and logistic regression were used to analyze the risk factors leading to WMSDs. Results:The incidence of WMSDs in cabinet production workers reached 51.5% (423/821) , and the top three incidences were shoulder (28.4%, 233/821) , neck (28.1%, 231/821) , and wrist (25.9%, 213/821) . The incidence of neck WMSDs was statistically significant among different types of work ( P<0.05) . Multiple repetitive operations per minute ( OR=1.70) , torso often maintaining the same posture ( OR=1.61) , turning heads for a long time ( OR=1.58) and frequent heavy lifting ( OR=1.44) were risk factors for the occurrence of shoulder WMSDs ( P<0.05) . Frequent maintenance of the same posture in the neck ( OR=1.91) , repeated operations per minute ( OR=1.87) , shortage of department staff ( OR=1.65) and turning head for a long time ( OR=1.48) were risk factors for the occurrence of neck WMSDs ( P<0.05) . Long-term bending of the wrist ( OR=2.25) , grasping objects tightly ( OR=2.13) , working hard on the upper limbs or hands ( OR=1.91) , shortage of department personnel ( OR=1.84) , repeated operations per minute ( OR=1.68) and the use of vibration tools ( OR=1.51) were risk factors for the occurrence of WMSDs in the wrist ( P<0.05) . Conclusion:The incidence of WMSDs in cabinet factory is relatively high, the occurrence of WMSDs in the shoulders, necks and wrists is more serious. Reasonable labor organization and reducing the load of poor ergonomics in the workplace, can reduce the occurrence of WMSDs in production workers.

Bus drivers, as an important occupational group in urban public transportation system, are prone to suffer from work-related musculoskeletal disorders (WMSDs) due to prolonged fixed postures and repetitive movements. The T/WSJD 14.9-2024 Ergonomic Guidelines for the Prevention of Work-related Musculoskeletal Disorders: Part 9: Bus Driving Work is a recommended standard developed to prevent WMSDs among bus drivers. This standard, guided by the principles of T/WSJD 14.1-2020 Ergonomic Principle for the Prevention of Work-related Musculoskeletal Disorders: Part 1: General Principles, is based on a preliminary work of comprehensive review of domestic and international research, workplace on-site surveys and questionnaires, data analysis, and factor identification. It defines the scope of application, identifies relevant risk factors and potential affected body parts, and offers ergonomic solutions in the form of intervention examples. The issuance of this guideline as a organization standard will facilitate the promotion and implementation of intervention measures.

Objective: The spatial distribution model of particulate matter based on time change in a specific place was established to analyze the spatial and temporal distribution characteristics and movement of particulate matter. Methods: A convenience store was selected as the research subject. The micro-climate and particle number concentration (PNC) of the site were detected, and numerical simulation was carried out by computational fluid dynamics (CFD) simulation method. Based on the discrete phase model, the temporal and spatial distribution characteristics and movement rules of simulated particles were analyzed. Results: The wind speed at the entrance of the convenience store was low and almost unchanged during the detection, while the wind speeds outside and inside outlets were high and changed sharply. The PNC of particle size of 0.02-1.00 μm was higher than that of particle size >1.00 μm (all P<0.05). The PNC with particle size of 0.02-1.00 μm from high to low were checkout counter, entrance, outer outlet and inner outlet (all P<0.05). The PNC of the checkout counter and entrance varies greatly, while the PNC of the outer outlet and inner outlet was relatively steady. The CFD simulation results showed that particles exhaled by individuals near the entrance of the checkout counter of the convenience store could be expelled outdoors more quickly with the influence of airflow. However, particles exhaled by individuals in the middle of the shelves remained suspended indoors for a longer period of time compared to those near the checkout counter. Particles emitted from the air conditioning outlet diffuse throughout the entire store and reach a steady state in 300 seconds. Conclusion: The particulate matter in the convenience store was mainly small particle with the size less than 1.00 μm. The residence time, downward trend and number of suspended particulates of human exhaled particles were related to air flow. The particulates escaped from the air conditioner could quickly spread to almost the entire convenience store.

Objective: To study the relationship between XRCC1 gene polymorphism and DNA damage in peripheral blood lymphocytes of workers exposed to coal tar pitch. Methods: 203 coal tar asphalt device operation area workers (exposure group) and 76 logistics management personnel (control group) as the research ob-ject, determination of 1-hydroxypyrene concentrations in the urine as polycyclic aromatic hydrocarbons expo-sure dose, using the alkaline comet assay evaluation a peripheral blood lymphocyte DNA damage degree, using TaqMan MGB real time PCR method to detect XRCC1 gene 3 loci (XRCC1-194, XRCC1-280 and XRCC1-399) single nucleotide polymorphism. Results: No significant differences was observed in age, sex, smoking and alco-hol consumption between the two groups (P>0.05). The level of 1-OHP in the exposed group was significantly higher than that in the control group (1.27±0.93 μg/g creatinine) (P<0.05). The comet Olive tail moment level (3.21±0.93) in the peripheral blood lymphocytes of the exposed group was significantly higher than that in the control group (0.94 ± 0.39) (P<0.05). There was no significant difference in genotype distribution of XRCC1-194, XRCC1-280 and XRCC1-399 between the two groups (P>0.05). There was a significant correlation be-tween the XRCC1-280 locus gene polymorphism and comet Olive tail moment in the exposure group (P<0.05) af-ter adjustment for sex, age, smoking rate, drinking rate, length of service and urinary 1-OHP concentration. The comet Olive tail moment level of GG individuals carrying wild homozygous genotype was significantly lower than that of individuals carrying heterozygous genotype GA and carrying mutant homozygous genotype AA (P< 0.05) , and the difference was statistically significant (P<0.05) The comet Olive tail moment level of heterozy-gous genotype GA was significantly lower than that of genotype AA with mutational homozygous genotype AA (P<0.05) , and the difference was statistically significant (P<0.05). Conclusion Arg280His locus polymor-phism of XRCC1 gene may influence the DNA damage level of peripheral blood lymphocytes induced by occupational exposure to coal tar pitch.