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 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 explore the attitude and behavior of scientific research in professional postgraduates majoring in stomatology in Peking University, proposing suggestions to improve the quality of scientific research training.Methods:150 professional postgraduates of stomatology including the 8-year program stomatological students (the postgraduate stage) of Peking University School of Stomatology were involved in the survey, information including the types of and attitudes to scientific research, the evaluation of research environments, the understanding of the relationship with their mentors, and the expected working institutions after graduation was collected by questionnaires.Results:A total number of 131 valid questionnaires were collected, with an effective rate of 87.3%. In terms of the type of research work, 70 (53.4%) were engaged in basic research and 30 (22.9%) in clinical research. In terms of attitudes towards scientific research training, 69 (52.7%) respondents agreed that scientific research and clinical practice promoted each other. The Likert scores of scientific research interest, ability, and pressure were 3.13 ± 0.84, 3.04 ± 0.84, and 4.14±0.71. The evaluation of laboratory conditions (3.30±0.92), scientific research funding (3.54±1.06), scientific research atmosphere (3.89±0.85), and reward and punishment mechanisms (3.82±0.76) were positive. The evaluations of scientific research training courses (2.89±0.88) and scientific training time (2.79±0.94) were negative. The average score of the rapport level between postgraduates and their mentors was 4.29±0.77, and 111 respondents (84.7%) had a correct understanding of the guiding relationship. Sixty-six respondents (50.4%) expected to engage in clinical and scientific research in stomatological schools and 61 (46.6%) expected to engage in clinical work only, after graduation.Conclusions:The scientific research for graduate students of stomatology in Peking University is mainly basic research, and the research pressure is relatively high. It is recommended to choose research topics in combination with clinical practice, clarify the significance of scientific research, optimize the scientific research environment and facilities, strengthen the tailored guidance of mentors, and to fulfill the " holistic training (Three All-round Education)" in professional postgraduate training.

Objective To clone the HnGUA gene from Hirudo nipponia and conduct bioinformatics analysis,protein prokaryotic expression analysis and gene differential expression analysis.Methods Based on the transcriptome data of H.nipponia in the previous study,the full-length cDNA of HnGUA was cloned by rapid amplification of cDNA ends(RACE),and bioinformatics analysis was performed.The prokaryotic expression vector was constructed,transformed into Escherichia coli BL21(DE3)competent cells and the expression of recombinant protein was induced by IPTG.The qPCR was used to further analyze the tissue-specific expression of HnGUA.Results The size of HnGUA gene was 504 bp,containing an open reading frame(ORF)of 231 bp and encoding 76 amino acids.Its protein molecular weight and isoelectric point are 8.17 kDa and 4.44,respectively.Multiple sequence alignment analysis showed that HnGUA was highly homologous to genes in other leech species that encode inhibitory proteins.The results of the prokaryotic expression analysis showed that the constructed pET32a-HnGUA vector could be successfully expressed in E.coli BL21(DE3),and the SDS-PAGE results showed that the induced recombinantly expressed HnGUA protein was around 6 kDa,which was basically consistent with the predicted protein size.The results of the Real-time PCR revealed spatial and temporal differences in the expression profiles of HnGUA,with high levels of expression detected in the skin and crop tissues.Conclusion This study represents the first successful cloning of the HnGUA gene from H.nipponia and the expression of the corresponding recombinant protein in E.coli.It provides a foundation for future exploration of the biosynthetic pathways and molecular regulatory mechanisms of active small anticoagulant molecules in leeches.

Objective To explore the value of T2*mapping in quantitatively evaluate changes in knee joint cartilage and subchon-dral bone of new recruits before and after intensive training.Methods MRI scans of the right knee joint were performed three times on 20 new recruits:before intensive training,after one week of intensive training,and after one month of rest.The knee joint cartilage was divided into six regions:lateral femur(LF),medial femur(MF),lateral tibia(LT),medial tibia(MT),patella cartilage(PC),and trochlea cartilage(TC).Using the posterior angle of the meniscus as a boundary,LF and MF were divided into the cLF/cMF and pLF/pMF.Divid-ed into superficial zone(SZ)cartilage and deep zone(DZ)cartilage based on a thickness of 1/2 of the cartilage.The subchondral bone was divided into superficial bone(SB)within 5 mm of the joint cartilage,and deep bone(DB)within 6-10 mm of the joint cartilage.The T2*values of each region of cartilage and subchondral bone were evaluated through region of interest(ROI)analysis.Single fac-tor analysis of variance was used to compare the changes in T2*values.The LSD test method was used for inter-group comparison.Results After one week of intensive training,MT-SZ,cMF-SZ,PC-SZ,TC-SZ were significantly higher than before intensive training(P＜0.05).After one month of rest,there was no statistically significant difference in the T2*value of the cartilage area compared with before intensive training(P＞0.05).There was a trend of"rising first and then falling".There was no statistically signifi-cant difference in the T2*value of subchondral bone of the knee joint before intensive training and after one week of intensive training(P＞0.05).Compared with after one month of rest,except for cLF-DB,pLF-DB,trochlea cartilage-deep bone(TC-DB),the T2*value of the subchondral bone of the remaining knee joint increased before intensive training and after one week of intensive training,with sta-tistically significant differences(P＜0.05).Conclusion T2*mapping can display the changes in the ultrastructure and biochemical components of joint cartilage and subchondral bone after the new recruits intensive training,detect early injuries and conduct non-invasive quantitative evaluation.

OBJECTIVE: To summarize the research progress on the role of macrophage-mediated osteoimmune in osteonecrosis of the femoral head (ONFH) and its mechanisms. METHODS: Recent studies on the role and mechanism of macrophage-mediated osteoimmune in ONFH at home and abroad were extensively reviewed. The classification and function of macrophages were summarized, the osteoimmune regulation of macrophages on chronic inflammation in ONFH was summarized, and the pathophysiological mechanism of osteonecrosis was expounded from the perspective of osteoimmune, which provided new ideas for the treatment of ONFH. RESULTS: Macrophages are important immune cells involved in inflammatory response, which can differentiate into classically activated type (M1) and alternatively activated type (M2), and play specific functions to participate in and regulate the physiological and pathological processes of the body. Studies have shown that bone immune imbalance mediated by macrophages can cause local chronic inflammation and lead to the occurrence and development of ONFH. Therefore, regulating macrophage polarization is a potential ONFH treatment strategy. In chronic inflammatory microenvironment, inhibiting macrophage polarization to M1 can promote local inflammatory dissipation and effectively delay the progression of ONFH; regulating macrophage polarization to M2 can build a local osteoimmune microenvironment conducive to bone repair, which is helpful to necrotic tissue regeneration and repair to a certain extent. CONCLUSION At present, it has been confirmed that macrophage-mediated chronic inflammatory immune microenvironment is an important mechanism for the occurrence and development of ONFH. It is necessary to study the subtypes of immune cells in ONFH, the interaction between immune cells and macrophages, and the interaction between various immune cells and macrophages, which is beneficial to the development of potential therapeutic methods for ONFH.
Humans ; Femur Head/pathology* ; Osteonecrosis/therapy* ; Macrophages/pathology* ; Inflammation ; Femur Head Necrosis/pathology*