Objective To understand the current situation and influencing factors of work-related musculoskeletal disorders (WMSDs) in medical staff in Beijing City. Methods A total of 2 687 medical staff were selected as the research subjects using the multi-stage sampling method. The current situation of WMSDs and occupational stress, anxiety symptoms, depressive symptoms, and insomnia symptoms were investigated using the Musculoskeletal Disorders Questionnaire, the Core Occupational Stress Scale, the Generalized Anxiety Disorder Scale, the Patient Health Questionnaire Depression Scale, and the Self-Sleep Management Questionnaire. The Max-Min Hill-Climbing algorithm was used to construct a Bayesian network model to analyze the influencing factors and internal relationships of WMSDs and to conduct reasoning and prediction of the model. Results The prevalence of WMSDs among the research subjects was 88.9%. Binary logistic regression analysis was used to identify age, educational level, personal monthly income, anxiety symptoms, depressive symptoms, insomnia symptoms, prolonged forward-head desk work, and prolonged static posture work to construct the Bayesian network model. The model consisted of nine nodes and eleven directed edges. Prolonged static posture work, prolonged forward-head desk work, and anxiety symptoms were directly related to WMSDs. Age and educational level were indirectly related to WMSDs through their influence on prolonged forward-head desk work. Depression symptoms were indirectly associated with WMSDs through their influence on anxiety symptoms. The model's prediction accuracy was 90.5%. Conclusion The prevalence of WMSDs among medical staff in Beijing City is relatively high. Prolonged static posture work, prolonged forward-head desk work, and anxiety symptoms may directly increase the risk of developing WMSDs.

Objective To evaluate the clinical effectiveness of single-incision intervertebral foraminotomy in treating double-segment lumbar spinal stenosis accompanied by lumbar disc herniation.Methods A retrospective analysis was conducted on 40 cases of double-segment lumbar spinal stenosis and lumbar disc herniation treated in our orthopedic(spinal surgery)department from March 2016 to May 2018.Among these cases,11 patients(Group A)were treated with percutaneous discectomy,13 patients(Group B)underwent percutaneous endoscopic discec-tomy,and 16 patients(Group C)received double-incision percutaneous surgery.General clinical data for all patients were recorded.Visual Analog Scale(VAS)scores,Japanese Orthopaedic Association(JOA)scores,and clinical outcomes were assessed at five different time points:preoperatively,immediately postoperatively,one week postoperatively,one month postoperatively,and at the final follow-up.Statistical analysis was performed on the collected data.Results The operation time,the number of fluoroscopies performed on the hands,the length of the skin incision,and patient satisfaction were all statistically significant(P<0.05).An interaction effect was observed between the operation time and the surgical procedure on both the VAS and JOA scores.Both the operation time and the surgical method had significant main effects on the VAS and JOA scores(P<0.05).Significant differences in VAS and JOA scores were found among the three groups immediately post-surgery,one week post-surgery,one month post-operation,and at the end of the study(P<0.05).Immediately after surgery,there were statistically significant differences in VAS and JOA scores among the three groups(P<0.05).One week post-surgery,there were also statistically significant differences in VAS scores among the three groups(P<0.05).Conclusions The single-incision intervertebral foramen technique is an effective approach for simultaneously addressing double-seg-ment lumbar spinal stenosis and lumbar disc herniation through decompression.This method boasts a shorter opera-tive duration,reduced intraoperative radiation exposure,and minimal tissue damage.Patient satisfaction is high,making it a valuable addition to clinical practice.

Objective To evaluate the clinical effectiveness of single-incision intervertebral foraminotomy in treating double-segment lumbar spinal stenosis accompanied by lumbar disc herniation.Methods A retrospective analysis was conducted on 40 cases of double-segment lumbar spinal stenosis and lumbar disc herniation treated in our orthopedic(spinal surgery)department from March 2016 to May 2018.Among these cases,11 patients(Group A)were treated with percutaneous discectomy,13 patients(Group B)underwent percutaneous endoscopic discec-tomy,and 16 patients(Group C)received double-incision percutaneous surgery.General clinical data for all patients were recorded.Visual Analog Scale(VAS)scores,Japanese Orthopaedic Association(JOA)scores,and clinical outcomes were assessed at five different time points:preoperatively,immediately postoperatively,one week postoperatively,one month postoperatively,and at the final follow-up.Statistical analysis was performed on the collected data.Results The operation time,the number of fluoroscopies performed on the hands,the length of the skin incision,and patient satisfaction were all statistically significant(P<0.05).An interaction effect was observed between the operation time and the surgical procedure on both the VAS and JOA scores.Both the operation time and the surgical method had significant main effects on the VAS and JOA scores(P<0.05).Significant differences in VAS and JOA scores were found among the three groups immediately post-surgery,one week post-surgery,one month post-operation,and at the end of the study(P<0.05).Immediately after surgery,there were statistically significant differences in VAS and JOA scores among the three groups(P<0.05).One week post-surgery,there were also statistically significant differences in VAS scores among the three groups(P<0.05).Conclusions The single-incision intervertebral foramen technique is an effective approach for simultaneously addressing double-seg-ment lumbar spinal stenosis and lumbar disc herniation through decompression.This method boasts a shorter opera-tive duration,reduced intraoperative radiation exposure,and minimal tissue damage.Patient satisfaction is high,making it a valuable addition to clinical practice.

Objective To analyze the current situation of depressive symptoms among medical staff in Beijing City and its correlation with symptoms of anxiety, occupational stress and insomnia. Methods A total of 2 687 medical staff from 28 medical institutions in eight municipal districts of Beijing City were selected as study subjects using multi-stage sampling method. The basic situation, depression symptoms, anxiety symptoms, occupational stress and insomnia symptoms were investigated using the National Occupational Health Literacy Monitoring Questionnaire for Key Groups, Patient Health Questionaire-9, 7-item Generalized Anxiety Disorder Scale, Core Occupational Stress Scale, and Self-Sleep Management Questionnaire. Results The detection rate of depressive symptoms was 28.3%, and the detection rates of moderate, moderate-severe and severe depressive symptoms were 18.9%, 6.9% and 2.5%, respectively. The detection rate of anxiety symptoms was 41.3%, and the detection rates of mild, moderate and severe anxiety symptoms were 29.7%, 7.7% and 3.9%, respectively. The detection rate of occupational stress was 26.7%. The detection rate of insomnia symptoms was 36.6%. The results of multivariate logistic regression analysis showed that the risk of depressive symptoms in male medical staff was higher than that in female (P<0.05). The risk of depressive symptoms in night shift staff was higher than that in staff without night shift (P<0.05). The more severe the anxiety symptoms, the higher the risk of depressive symptoms (all P<0.01). The risk of depressive symptoms in medical staff with occupational stress was higher than those without occupational stress (P<0.01). The risk of depressive symptoms in medical staff with insomnia symptoms was higher than those without insomnia symptoms (P<0.01). Conclusion The detection rate of depressive symptoms among medical staff in Beijing City is relatively high. Gender, night shift, anxiety symptoms, occupational stress, and insomnia symptoms were independent risk factors of depressive symptoms.

Objective To evaluate the applicability of the comprehensive index method for assessing occupational health risks on chemical hazards in key work sites of a metal product enterprise. Methods A metal product enterprise in Beijing City was chosen as the research subject using the convenience sampling method. Occupational health investigations and chemical hazard monitoring were conducted at four work sites: grinding machine operation, welding, cutting, and painting. The comprehensive index method was used to determine the risk levels of chemical hazards. Results The grinding dust in the grinding machine operation work site was assessed as moderate risk. The nitrogen oxides and ozone in the welding (southeast) work sites were assessed as moderate risk. The nitrogen oxides ozone and welding fumes in the welding (northwest) and cutting work site were assessed as moderate risk. Benzene in the painting work site was assessed as moderate risk. All chemical hazards in other work sites were determined to pose low risks. Co-exposures to nitrogen oxides and ozone in the two welding work sites and cutting work site were classified as moderate risk. Co-exposure to ethylbenzene, xylene, methanol, ethyl acetate, and butyl acetate in the painting work site also posed moderate risk, while the co-exposure to toluene and methanol in the painting work site was assessed as low risk. Conclusion The comprehensive index method could be used for the occupational health risk assessment in the metal product enterprise. The enterprise should strengthen hazard control measures for exposure to grinding dust, welding fumes, nitrogen oxides, ozone, and benzene, and closely monitor the health risks associated with co-exposures of chemical hazards.

Objective To investigate the relationship between lesion size of solitary bone cyst ( SBC) and pathological fracture of calcaneus, so as to provide references for the treatment of SBC. Methods The three dimensional (3D) finite element model of foot and ankle was established based on CT images. Four models with gradient spherical bone defects were constructed in the focal area to simulate different SBC lesion sizes, and the biomechanical characteristics of calcaneus in different gait phases were analyzed. Results With the increasement of SBC size, the kinematics of calcaneus did not change significantly, but the peak stress of calcaneus increased gradually. When the SBC size exceeded 75% of the calcaneal width, the stress in calcaneal sulcus and cortical bone below SBC increased by 1. 48 times and 7. 74 times, respectively. Conclusions The risk of pathological fracture increases when the SBC diameter exceeds 75% of the calcaneal width, and early surgical intervention should be recommended. The calcaneal sulcus and the cortex bone below SBC are stress concentration regions and can be used as important areas to evaluate pathological fractures.

This study aims to analyze the biomechanical stability of Magic screw in the treatment of acetabular posterior column fractures by finite element analysis. A three-dimensional finite element model of the pelvis was established based on the computed tomography (CT) and magnetic resonance imaging (MRI) data of a volunteer and its effectiveness was verified. Then, the posterior column fracture model of the acetabulum was generated. The biomechanical stability of the four internal fixation models was compared. The 500 N force was applied to the upper surface of the sacrum to simulate human gravity. The maximum implant stresses of retrograde screw fixation, single-plate fixation, double-plate fixation and Magic screw fixation model in standing and sitting position were as follows: 114.10, 113.40 MPa; 58.93, 55.72 MPa; 58.76, 47.47 MPa; and 24.36, 27.50 MPa, respectively. The maximum stresses at the fracture end were as follows: 72.71, 70.51 MPa; 48.18, 22.80 MPa; 52.38, 27.14 MPa; and 34.05, 30.78 MPa, respectively. The fracture end displacement of the retrograde tension screw fixation model was the largest in both states, and the Magic screw had the smallest displacement variation in the standing state, but it was significantly higher than the two plate fixations in the sitting state. Magic screw can satisfy the biomechanical stability of posterior column fracture. Compared with traditional fixations, Magic screw has the advantages of more uniform stress distribution and less stress, and should be recommended.
Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Finite Element Analysis ; Fracture Fixation, Internal/methods* ; Fractures, Bone/surgery* ; Humans ; Spinal Fractures

Objective:To evaluate the effects of mouse nerve growth factor (mNGF) on the brain water content and the expressions of β-amyloid precursor protein (β-APP) and neurofilament light polypeptide (NF-L) in rats with traumatic brain injury (TBI) complicated by seawater drowning (SWD). Methods:A total of 60 male rats were randomly divided into three groups: Sham group ( n=12), TBI+ SWD group ( n=24), and mNGF group ( n=24). The rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. The mNGF group was administered mNGF intraperitoneally; while the Sham group and the TBI+ SWD group were injected with an equivalent amount of normal saline. The brain water content was measured by using the dry-wet weight method. The pathological changes of the hippocampal tissue and the expressions of β-APP and NF-L were observed through hematoxylin-eosin (HE) staining and immunohistochemical (IHC) staining. Results:Brain water content in the mNGF group was similar to that in the TBI+ SWD group ( P>0.05). Compared with the TBI+ SWD group, the expressions of β-APP and NF-L in the hippocampal tissue of the mNGF group were significantly reduced. Conclusion:mNGF can reduce the expressions of β-APP and NF-L, and protect the neurons of the rats after TBI+ SWD.

Objective:To evaluate the effects of mouse nerve growth factor (mNGF) on the brain water content and the expressions of β-amyloid precursor protein (β-APP) and neurofilament light polypeptide (NF-L) in rats with traumatic brain injury (TBI) complicated by seawater drowning (SWD). Methods:A total of 60 male rats were randomly divided into three groups: Sham group ( n=12), TBI+ SWD group ( n=24), and mNGF group ( n=24). The rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. The mNGF group was administered mNGF intraperitoneally; while the Sham group and the TBI+ SWD group were injected with an equivalent amount of normal saline. The brain water content was measured by using the dry-wet weight method. The pathological changes of the hippocampal tissue and the expressions of β-APP and NF-L were observed through hematoxylin-eosin (HE) staining and immunohistochemical (IHC) staining. Results:Brain water content in the mNGF group was similar to that in the TBI+ SWD group ( P>0.05). Compared with the TBI+ SWD group, the expressions of β-APP and NF-L in the hippocampal tissue of the mNGF group were significantly reduced. Conclusion:mNGF can reduce the expressions of β-APP and NF-L, and protect the neurons of the rats after TBI+ SWD.

Objective: To investigate the prevalence of reproductive system diseases among female workers in a city and related occupational influencing factors. Methods: From June to September, 2016, a cross-sectional survey was used to select 9 944 female workers from six districts of Beijing and then a face-to-face questionnaire survey was performed. Univariate analysis using chi-square test and multivariate logistic regression analysis were used to investigate the risk factors for reproductive system diseases. Results: The age of 9944 female workers ranged from 18 to 65 years (mean 35.53±9.52 years) , and among them, 7 351 (73.92%) were married. The overall prevalence rate of reproductive system diseases among these 9944 female workers during the past three months was 28.29%, and the prevalence rates of hyperplasia of mammary glands, vaginitis, and hysteromyoma were 15.54%, 11.25%, and 6.77%, respectively. After adjustment for age, marital status, education level, and annual family income, the multivariate logistic regression analysis showed that frequent overtime work (odds ratio[OR]=1.119, 95% confidence interval[CI]: 1.070-1.343) , frequent night shifts (OR=1.198, 95%CI: 1.054-1.361) , standing for a long time (OR=1.197, 95%CI: 1.063-1.347) , sitting for a long time (OR=1.327, 95%CI: 1.191-1.479) , heavy workload (OR=1.429, 95%CI: 1.262-1.615) , exposure to lead (OR=1.696, 95%CI: 1.307-2.201) , exposure to mercury (OR=1.452, 95%CI: 1.086-1.940) , and exposure to ionizing radiation (OR=1.679, 95%CI: 1.424-1.980) were associated with reproductive system diseases. Conclusion The prevalence of reproductive system diseases among female workers in Beijing is not optimistic. Reproductive system diseases are associated with frequent overtime work, frequent night shifts, standing for a long time, sitting for a long time, heavy workload, and exposure to lead, mercury, and ionizing radiation.