{L-End}Objective To investigate the current status and influencing factors of leg work-related musculoskeletal disorders (WMSDs) in shipbuilding workers. {L-End}Methods A total of 3 393 shipbuilding workers from Guangdong Province, Liaoning Province, Shandong Province, and Beijing City were selected as the research subjects using the convenience sampling method. The Chinese Version of the Musculoskeletal Disorders Questionnaire was used to investigate the prevalence of leg WMSDs in the past year. A multivariate logistic regression model was used to analyze the influencing factors of leg WMSDs. {L-End}Results The prevalence of leg WMSDs in the research subjects was 11.3% (382/3 393). The result of multivariate logistic regression showed that the risk of leg WMSDs was higher in workers with a length of service >10 years than those with a length of service <5 years (P<0.05). Workers with frequent used of vibration tools at work had higher the risk of leg WMSDs (all P<0.05). Workers who did the same work every day, had insufficient rest time, had a shortage of department staff, and those who often repeated the same leg movements had a higher risk of leg WMSDs (all P<0.05). The risk of leg WMSDs in workers who sometimes stand for a long time was lower than that in workers who rarely stand for a long time (P<0.01). {L-End}Conclusion Length of service, rarely long-standing work, use of vibration tools at work, daily engagement in the same work, in-adequate rest time, shortage of department staff, and frequent repetition of the same leg movements are all influencing factors for leg WMSDs in shipbuilding workers.

Background Prolonged awkward postures during occupational activities can lead to excessive musculoskeletal load on the wrist of workers and symptoms such as wrist pain or discomfort. Objective To survey the prevalence of wrist pain among workers in 10 key industries and analyze its correlation with wrist working postures. Methods By using stratified cluster sampling method, workers from 10 key industries, such as footwear manufacturing industry, shipbuilding manufacturing industry, and automobile manufacturing industry, were selected from seven regions in North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China. The demographic information, wrist working postures, pain in wrist of the workers were collected through a cross-sectional survey. Pearson χ² test was used to compare prevalence by selected factors, trend χ² test for between group comparison, and unconditional logistic regression models for the association of wrist working postures with wrist pain. Results There were 64052 workers enrolled in this survey, and 56286 provided valid questionnaires (the effective rate was 87.8%). According to the survey, the prevalence of wrist pain was 23.3% (13112/56286), and the industries with higher prevalences were footwear manufacturing (27.1%, 1927/7106), automobile manufacturing (24.9%, 5378/21560), and shipbuilding and related equipment manufacturing (24.4%, 850/3488) industries. Finger pinching (OR=2.09, 95%CI: 1.95-2.24), frequent wrist bending (OR=2.03, 95%CI: 1.92-2.15), fixed wrist bending (OR=1.77, 95%CI: 1.69-1.85), wrist on hard edge (OR=1.34, 95%CI: 1.28-1.40), and arms over shoulders (OR=1.11, 95%CI: 1.05-1.17) increased the risk of reporting wrist pain. Conclusion Awkward postures are related to wrist pain among workers in selected 10 key industries. The related factors are wrist on hard edge, frequent wrist bending, finger pinching, fixed wrist bending, and arms over shoulders.

Objective: To analyze the current status of work-related musculoskeletal disorders (WMSDs), work fatigue and musculoskeletal pain in Chinese occupational population, and to study the relationship between work fatigue and musculoskeletal pain and WMSDs. Methods: A total of 66 961 employees from 323 enterprises in 15 key industries in China were selected as the study subjects using stratified cluster sampling method. The incidence of WMSDs in the past year was investigated using the Chinese version of the Musculoskeletal Disorders Questionnaire, and the work fatigue and musculoskeletal pain were investigated using Borg 6-20 Rating of Perceived Exertion Scale and visual analogue scale. The data were standardized using the age composition data of 18 to 60 years from the seventh national population census. Results: The standardized annual incidence of WMSDs was higher in the front-line workers than that in the administrative and other supportive staff (38.82% vs 36.30%). The detection rates of work fatigue and musculoskeletal pain in the study subjects were 44.54% and 63.08%, respectively. The result of S-curve fitting showed that the risk of WMSDs increased with the level of work fatigue (P<0.01). Among the front-line workers, the average of monthly fatigue frequency in the neck, shoulder, lower back, upper back, wrist/hand, foot and ankle, knee, leg, and elbow were higher in the group with WMSDs compared to those without WMSDs (all P<0.01). The pain degree of musculoskeletal pain was higher in all nine sites in the fatigued group than in the no-fatigue group (all P<0.01). The standardized detection rate of musculoskeletal pain was higher in the fatigued group than in the non-fatigued group (80.38% vs 25.71%). The work fatigue was moderate and positively correlated with musculoskeletal pain in all seven sites except the lower back and elbow, with Kendall Tau-b correlation coefficients ranging from 0.423 to 0.546 (all P<0.01). Conclusion: There is a good correlation between work fatigue and local musculoskeletal pain, work fatigue and WMSDs in Chinese occupational population. Implementing ergonomic interventions to control the development of work fatigue can be an effective measure for preventing WMSDs.

Objective:Rapid assessment of the outcome after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) is an important clinical issue. In this study, an electrocardiogram (ECG) analysis method based on dynamic learning was proposed.Methods:A total of 203 patients with ACS after successful PCI were enrolled for prospective analysis at the Emergency Department of Qilu Hospital of Shandong University from April 2019 to December 2020. All patients were divided into group without ≥70% postoperative stenosis ( n=72) and group with ≥ 70% postoperative stenosis ( n=131) according to the presence of 70% or more stenosis after PCI. The clinical data of ACS patients were collected and analyzed by χ2 test, t-test, or Mann-Whitney test. ECGs were recorded before and 2 h after PCI, and were dynamically analyzed to generate cardiodynamicsgram (CDG) using dynamic learning. In the group without ≥ 70% postoperative stenosis, the model and CDG index for evaluating myocardial ischemia were obtained by training support vector machine (SVM) using 10 times 10-fold cross-validation. Results:There was no significant difference in clinical data between the two groups. The prediction accuracy and sensitivity of the support vector machine model for myocardial ischemia in group without≥70% postoperative stenosis were 73.61%, and 84.72% respectively. CDG transformed from disorderly to regular after PCI, and CDG index decreased significantly ( P<0.001): 90.28% (65) patients in group without≥70% postoperative stenosis, and 79.39% (104) patients in group with≥70% postoperative stenosis had lower CDG indexes than before PCI. Conclusions:In this study, CDG obtained by dynamic learning can intuitively and effectively evaluate the changes of myocardial ischemia before and after PCI, which is helpful to assist clinicians to formulate the next treatment plan.

Objective:To estimate the safety of myomectomy in twin pregnant women with intramural myomas during cesarean section.Methods:The clinical data of 145 cases of twin pregnancies with intramural myomas who were delivered by cesarean section in Beijing Obstetrics and Gynecology Hospital, Capital Medical University from June 2013 to December 2021 were collected. Maternal demographics, fibroids′ characteristics, maternal and fetal outcomes were compared between groups of cesarean section with myomectomy (myomectomy group, 49 cases) and cesarean section only (non-myomectomy group, 96 cases).Results:Compared with non-myomectomy group, myomectomy group had significantly prolonged operative time [50.0 minutes (37.5-57.5 minutes) vs 40.0 minutes (35.0-50.0 minutes), respectively; P=0.007] and significantly longer postoperative hospital stay [4.0 days (3.0-4.0 days) vs 3.0 days (3.0-4.0 days), respectively; P=0.047). Other maternal and fetal outcomes such as estimated blood loss, hemoglobin difference, postpartum hemorrhage, blood transfusion, B-Lynch structure, uterine artery ligation, postoperative fever and neonatal Apgar score showed no significant differences (all P>0.05). For intramural myomas <5 cm, there were no significant differences in maternal and fetal outcomes between myomectomy group and non-myomectomy group (all P>0.05). For intramural myomas ≥5 cm, operative time [55.0 minutes (40.0-60.0 minutes) vs 42.5 minutes (40.0-50.0 minutes), respectively; P=0.019] was significantly prolonged, postoperative hospital stay [4.0 days (4.0-5.0 days) vs 4.0 days (3.0-4.0 days), respectively; P=0.048] was significantly longer in myomectomy group than non-myomectomy group, but there were no significant differences in other maternal and fetal outcomes (all P>0.05). Conclusion:For twin pregnancies with intramural myomas, it is safe and feasible to remove intramural myomas during cesarean section by experienced obstetricians.

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 studythe cephalocaudal relationship ofabdominal aortic bifurcation relative toumbilicus and iliac crest vertex and their correlations with abdominal adipose tissue thickness and age. Methods The vertical distances,cephalocaudal relationship and other related anatomic parameters of aortic bifurcation relative to umbilicus and iliac crest vertex in 108 patientswere measured by consecutive abdominal CT scanning. The correlations of the acquired data with abdominal adipose tissue thickness and age were analyzed using Pearson correlation coefficient. Results Umbilicus was located at cephalad to aortic bifurcation in 67 patients(62.0%), caudal in 34(31.4%)andthe same level in 7(6.5%),with the vertical distance of(4.53 ± 17.51)mm to the aortic bifurcation. No statistically significant relationship was found between abdominal adipose tissue thickness(P>0.05) or age(P>0.05). Iliac crest vertex relative to aortic bifurcationwas located at cephalad,caudal and the same level in 31,71 and 6 patients,taking up 28.7%,65.7%and 5.6%,respectively. Its vertical distance to the bifurcation was(-6.34 ± 14.49)mm,nonrelated with abdominal adipose tissue thickness(P>0.05),but positively correlated with age(P<0.01). The difference in the cephalocaudal relationship of aortic bifurcation relative to umbilicus and iliac crest vertex was statistically significant(P<0.01). Conclusion Compared with iliac crest vertex,umbilicus is an important landmark of locating abdominal aortic terminal occlusion position in vitro because it mostly lies cephalad to aortic bifurcation in the front of the body,not easy to vary with abdominal adipose tissue thickness and age.

Objective To investigate the effect of perioperative treatment and protection in human immunodeficiency virus (HIV) infected patients with osteoporotic vertebral compression fracture by percutaneous kyphoplasty (PKP).Methods From February 2010 to December 2015,206 cases with osteoporotic vertebral compression fracture treated by PKP were admitted,including 13 HIV infected patients.Blood routine,biochemical indexes,liver and kidney function,blood coagulation function,immune index and preoperative nutritional status were detected before operation.Highly active antiretroviral therapy (HAART),reasonable antibiotics,nutritional and immune support were given to the HIV infected patients.Standardized operation process and meticulous operative manipulation were applied during operation.The prevention of occupational exposure protection standardization process was strictly enforced.The postoperative complications,improvement of immune function and nutritional status,vertebral height,VAS,ODI and exposure occupation of medical personnel were observed.Results All 13 HIV infected patients had successful operations,without bone cement leakage and toxic reaction.One patient had perficial infection and the others had operative incisionprimary healing.There was no death.The levels of vertebral height,VAS scores and ODI scores were significantly improved after intervention and at the end of follow-up (P ＜ 0.05),but there were no significant differences between after the intervention and at the end of follow-up (P ＞ 0.05).Eleven malnutrition patients with HIV infected were received nutritional and immune support,and the levels of CD4 +,ALB and Hb were significantly improved:(289.00 ± 54.29) × 106./L vs.(237.25 ± 72.70) × 106/L,(38.04 ± 5.17) g/L vs.(33.73 ± 7.16) g/L,(112.87 ± 15.54) g/L vs.(100.68 ± 18.95) g/L,P ＜ 0.05.The levels of PLT and WBC had no significantly change (P ＞ 0.05).Two medical personnel had occupational exposure,and none had HIV infection.Conclusions Perioperative adjuvant treatment in HIV infected patients with osteoporotic vertebral compression fracture can achieve satisfactory outcomes.Strict implementation of protective standardization process should be focused.

Objective To observe the effect of perioperative treatment on complications in human immunodeficiency virus positive patients undergoing spinal surgery, and summarize effective perioperative management to make these patients to get better treatment. Methods Forty-eight HIV positive patients (experimental group) and 79 HIV negative patients (control group) undergoing spinal surgery from November 2010 to March 2016 were retrospectively reviewed. The two groups were comparable in age, gender, type of spinal surgery and basic diseases. Nutritional support and the uses of antibiotics and blood transfusion were strengthened in patients of experimental group. Immunomodulatory drugs, the treatment with HAART and occupational protection were also used in patients of experimental group. The patients in control group only received conventional perioperative treatment. Wound healing, opportunistic infection, the failure of internal fixation and death after the operation was observed. The perioperative treatment methods were summarized. Chi square test was used in comparison of the rate and P < 0.05 was considered statistically significant. Results Surgery was successfully completed in all patients in experimental group and control group. Two cases (4.2%) in experimental group and 4 cases(5.1%) in control group showed delayed healing of incisions. All incisions were healed after debridement and no incision infection happened. CD4+T lymphocyte count of 2 cases in the experimental group was in stage 3. Among them, 1 patient underwent emergency surgery and opportunistic infection appeared after the operation. The other patients for elective surgery took operation when CD4+T lymphocyte counts were adjusted to 2 and no complications appeared. The two groups had no internal fixation failure cases and deaths. Conclusions HIV positive patients with spinal diseases are special patients. HIV positive patients with spinal surgery can reduce complications, and achieve good clinical curative effect by reasonable preoperative assessment, optimization of perioperative treatment, proper type of operation and active prevention of opportunistic infections after surgery.

Objective To construct a colon cancer chemotherapy-resistant cell line COLO,and study its characteristics and its relationship with tumor stem cells.Methods We constructed two 5-fluorouraci (5-FU)-resistant colon cancer cell line COLO/5-FU-1 and COLO/5-FU-2, which were resistant to 0.1 0 μmol/ml and 0.20 μmol/ml 5-FU respectively through gradiently increased drug concentration.The cha-racteristics of 5-FU-resistant cell lines were compared with parental colon cancer cell line COLO related to proli-feration,colony forming ability,migration and invasion,sphere forming ability,expression of stemness genes and cross drug-resistance.Results In the cell viability assay,4 days after regular training,the absorbancy of colon cancer 5-FU-resistant cell lines COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were 0.61 ±0.1 3,0.54 ±0.07 and 0.41 ±0.09 respectively,with significant difference (F =63.43,P =0.033).With the increased concentration of 5-FU,5-FU-resistant cell lines presented increasing clonality. The cloning efficiency of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were (87.6 ±1 2.7)%,(65.3 ±9.7)% and (38.5 ±7.6)% respectively,with significant difference (F =33.64, P =0.01 7).In each high power field of vision,the cell numbers of migration through the basement membrane of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were 482 ±39,434 ±45 and 373 ±38 respectively;and the cell numbers of invasion through the basement membrane were 1 74 ±42,1 1 2 ± 31 and 87 ±29 respectively,with significant differences (F =1 09.61 ,P =0.009;F =67.31 ,P =0.032). Compared with parental colon cancer cell line COLO,5-FU-resistant cell lines had higher expression of stem-ness genes (F =47.31 ,P =0.042).5-FU-resistant cell lines were cross-resistant to other chemotherapeutic drugs such as mitoxantrone.For example,after incubation for 96 hours,inhibition rate of mitoxantrone to parent colon cancer cell line COLO was higher significantly than COLO/5-FU-1 and COLO/5-FU-2 (0.749 ± 0.042,0.423 ±0.024,0.342 ±0.01 8),with significant difference (F =1 2.61 ,P =0.028).The micro-sphere forming rates of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were (8.90 ± 0.97)%,(6.20 ±0.75)% and (3.90 ±0.32)% respectively,with significant difference (F =1 64.32,P =0.006).Conclusion Colon cancer drug-resistant cell line COLO possess tumor stem cell-like characteristics, which are enriched in cancer stem cells.