OBJECTIVE To observe the changes of cardiac function,local inflammation level and macrophage M2 polarization in mice with acute myocardial infarction(AMI after electroacupuncture preconditioning at the Neiguan point,and to explore the possible mechanisms from the perspective of regulating the DNA-PK/Rictor/Myc signaling pathway.METHODS Male C57BL/6J mice were randomly divided into sham group,model group and electroacupuncture group,with 10 mice in each group.The electroacupuncture group received bilateral electroacupuncture interventions at the Neiguan points,sparse-dense wave,2/15 Hz,1 mA,20 min/time,once a day for 3 consecutive days,and AMI models were performed 0.5 h after the electroacupuncture interventions.The myocardial ischemia model was prepared by ligating the left anterior descending branch.Echocardiography was used to detect cardiac ejection frac-tion(EF and fractional shortening(FS to evaluate cardiac function;HE and TUNEL staining were used to observe the pathological morphology of myocardium and apoptosis of cardiomyocytes,and immunohistochemistry and ELISA were used to detect IL-1β,TNF-α and NLRP3 in infarcted myocardium and peripheral blood to evaluate the level of inflammation;flow cytometry was used to detect cardiac macrophage polarization status,and Western blot method to detect the protein expression levels of DNA-PK,p-DNA-PK,Rictor and Myc in infarcted myocardium.RESULTS Compared with the sham group,the model group showed significantly lower EF and FS(P<0.000 1,significant inflammatory cell infiltration,significantly higher cardiomyocyte apoptotic index(P<0.001,up-regulated expression of IL-1β,NLRP3 and TNF-α in the myocardium and serum(P<0.01,P<0.001,a significant increase in the percentage of macrophages(P<0.001,a decrease in the percentage of cardiac M2-type macrophages(P<0.000 1,and a significant decrease in the expression levels of p-DNA-PK,Rictor and Myc proteins in myocardium(P<0.05,P<0.000 1.Compared with the model group,EF and FS were significantly higher in the electroacupuncture group(P<0.000 1,inflammatory cell infiltration was re-duced,cardiomyocyte apoptotic index was decreased(P<0.01,and the expression of IL-1β,NLRP3 and TNF-α was down-regula-ted in myocardium and serum(P<0.05,P<0.01,P<0.001;the macrophage percentage was decreased(P<0.05,cardiac M2-type macrophage percentage was increased(P<0.01,and p-DNA-PK,Rictor and Myc protein expression was enhanced in myocardium(P<0.05,P<0.01,P<0.000 1.CONCLUSION Electroacupuncture preconditioning may promote macrophage M2 polarization,attenuate local inflammation,and reduce cardiomyocyte apoptosis by modulating the DNA-PK/Rictor/Myc signaling pathway,thus im-proving cardiac function and achieving myocardial protective effects.

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.

Background The converter stations of high-voltage direct current (HVDC) transmission lines generate special total electric fields. At present, few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health. Objective To understand the current situation of total electric field strength in the workplace of converter stations. Methods Using purposive sampling, a calibrated HDEM-1 direct current (DC) total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines (DL/T 1089—2008). The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at ±800 kV UHV DC converter station (DL/T 275—2012), the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Results A total of 615 check points were planned, the total electric field strength was 0.05-37.05 kV·m⁻¹, and the median was 10.45 kV·m⁻¹. The total electric field strength of 39 check points (6.3%) exceeded 25 kV·m⁻¹ (the limits of ACGIH and ICNIRP), and the total electric field strength of 12 check points (2.0%) exceeded 30 kV·m⁻¹ (the limit of DL/T 275—2012). There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m⁻¹ between the neutral regions and the positive regions and between the neutral regions and the negative regions (P < 0.01). The proportion of total electric field strength exceeding 30 kV·m⁻¹ in the negative regions was higher than that in the positive regions (P < 0.01). There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes (P > 0.05). There were no significant differences in the proportions of total electric field exceeding 25 kV·m⁻¹ and exceeding 30 kV·m⁻¹ in converter stations at different voltage levels and different altitudes (P > 0.05). Conclusion The total electric field in some workplace of converter stations exceeds selected limits. Converter station operators may be exposed to high-strength total electric field for a short time.

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: To analyze the status of noise hazard in workplace of key industries in Guangdong Province. Methods: A total of 1 061 enterprises from 14 key industries in 21 prefecture-level cities in Guangdong Province were selected as the research subjects using stratified sampling method. The occupational health survey was carried out, and the noise intensity in the workplace was detected. Results: There were 12 606 workplaces and 5 570 work sites involved among 1 061 enterprises. The median and the 0-100th percentile value ［M (P₀-P₁₀₀)］ of noise intensity in workplace were 82.6 (46.5-112.6) dB(A), and 35.03% of the workplace exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in workplace were in the northern part of Guangdong and the stone processing industry respectively. The M (P₀-P₁₀₀) of noise intensity in the work sites was 83.7 (47.5-106.2) dB(A), and 36.00% of the work sites exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in work sites were in the Pearl River Delta region and the ferrous metal mining and dressing industry respectively. The rate of noise protection facilities setting was 66.45%, and the validity of personal protection was 61.73%. The occupational medical examination was performed in 73.24% of the research subjects, and 3.25% of the result was abnormal. The industry with the highest occupational medical examination rate was nonferrous metal smelting and rolling processing, and the industry with the highest abnormal rate of occupational medical examination was stone processing industry. Conclusion: Noise hazards in workplaces of key industries in Guangdong Province are relatively severe, necessitating strengthened supervision and management, noise control measures, and efforts to reduce noise exposure levels in workplaces and work sites.

Objective To analyze the characteristics of work-related musculoskeletal disorders (WMSDs) among sonographers in Guangdong Province, and to explore the disease pattern of the cases. Methods A total of 512 sonographers from 31 hospitals in Guangdong Province were selected as the research subjects using stratified cluster sampling method. The prevalence of WMSDs in the past year was investigated using the Musculoskeletal Disorders Questionnaire, and the characteristics of WMSDs were analyzed. Latent class analysis was used to identify the disease pattern of WMSDs. Results The overall prevalence of WMSDs was 94.3%. The top five affected body parts were right shoulder, neck, right hand/wrist, lower back and right forearm/elbow, with the prevalence of 80.3%, 75.4%, 61.1%, 55.5% and 45.3%, respectively. The prevalence of WMSDs was higher on the right side for the shoulder, hand/wrist, forearm/elbow, hip/leg and knee compared with the left side (80.3% vs 31.3%, 61.1% vs 13.9%, 45.3% vs 10.0%, 17.4% vs 8.6%, 13.1% vs 8.4%, all P<0.05). The prevalence of WMSDs increased with work years, as well the prevalence of WMSDs in the top five affected body parts among the sonographers (all P<0.05). However, there were no statistical differences in prevalence of WMSDs between general hospitals and maternal and child health hospitals, tertiary hospitals and non-tertiary hospitals, Pearl River Delta hospitals and non-Pearl River Delta hospitals; there was also no statistical difference between different genders and age groups of the sonographers (all P>0.05). The best-fit latent disease pattern for sonographers WMSDs comprised three categories： symptom of neck-right shoulder, symptom of neck-lower back-right shoulder-right elbow-right hand/wrist, and symptom of multi-parts above the knees, with the latent probabilities of 0.438, 0.427 and 0.135, respectively. Conclusion The prevalence of WMSDs in sonographers is extremely high, with a dose-effect relationship with work years. The most common affected parts are neck, lower back and right shoulder, right hand/wrist, and right forearm/elbow. The prevalence of WMSDs in the right side of limb was higher than that in the left. WMSDs primarily occur in multiple parts simultaneously. The most common symptoms occur in the neck-right shoulder and neck-lower back-right shoulder-right elbow-right hand/wrist.

Objective To investigate the level of finger systolic blood pressure (FSBP) in healthy young adults. Methods A total of 28 healthy young adults were selected as the study subjects by convenient sampling method. The FSBP of the study subjects was detected at 30 and 10 ℃, and the FSBP index (F_i) was calculated. Results The FSBP of the study subjects at 30 and 10 ℃ were (102.0±16.5) and (104.4±15.2) mmHg, respectively. The FSBP in male group at 30 and 10 ℃ was (99.6±18.6) and (107.2±17.0) mmHg, respectively. The FSBP in female group at 30 and 10 ℃ was (104.4±13.9) and (101.5±2.8) mmHg, respectively. The results of factorial analysis showed that the interaction between gender and temperature on FSBP was statistically significant (P<0.05). FSBP in male group was higher at 10 than 30 ℃ (P<0.05) and higher than female group at 10 ℃ (P<0.05). There was no statistical significance for the main effect of gender, temperature, finger, or the interaction effect of gender and finger, temperature and finger for FSBP (all P>0.05). The average F_i of the study subjects was (98.0±16.6)%, with males and females having the average F_i of (100.7±20.7) % and (95.2±10.6) % respectively. The results of factorial analysis of variance showed that there was no significant difference on F_i in the main effect gender and fingers or the interaction effect between them(all P>0.05). Conclusion The FSBP test could be used as a detection method for assessing peripheral microcirculation function in Chinese population. However, further research is needed to establish reference ranges and influencing factors.

Abstract OBJECTIVE To determine the index weight, optimize the extraction process of gastropathy oral thick paste 1. METHODS Taking the amount of water added, extraction time and extraction times as factors, depend on the single factor experiment, L9(34) orthogonal table was selected to design the experiment. The content of chlorogenic acid was determined by HPLC and the content of total flavonoids content was determined by ultraviolet spectrophotometry. With the above two contents plus the yield of dry extractum as the evaluation index, the weights were assigned based on the analytic hierarchy process, entropy weight method and independence weight method, and the extraction process was optimized by orthogonal experimental design. RESULTS Multi-index scoring was more scientific and reasonable, and the final optimal extraction conditions for gastropathy oral thick paste 1 were as follows: add 8 times the amount of water, extract twice and 0.5 h for each time. CONCLUSION The optimized extraction process using analytic hierarchy process, entropy weight method and independence weight method is reasonable, feasible, stable, and reproducible, which is suitable for the preparation of gastropathy oral thick paste 1, providing reference for subsequent research and development.

In this study, the virtual simulation tutoring system was applied to the teaching of dental residents in the standardized training stage for the first time, including the curriculum preparation, curriculum design and teaching practice. Through the practice of the preparation of class Ⅱ holes and the tooth preparation of PFM (porcelain fused to metal) by the dental residents in the virtual simulation teaching system, the teaching arrangement of three courses as one term was explored. Each course adopted the matching interactive teaching mode. Finally, the transcripts would be given by the virtual simulation teaching system to comment and summarize. This study has laid a foundation for future promotion of virtual simulation teaching system in the standardized training stage of stomatology residents and found a new direction for improving the proficiency and accuracy of residents' clinical operation skills.

Objective:To evaluate the detection accuracy of hepatitis B virus (HBV) serological markers among grassroots medical institutions in the demonstration areas of infectious diseases.Methods:A fixed sampling method was used among the followed-up hepatitis B cohort in general population of six infectious disease demonstration areas nationwide. Blood samples of chosen objects were collected, in which HBsAg and anti-HBs were tested by grassroots medical institutions and were also parallely tested by the third-party platform. The test results were compared between the two groups. Statistical analyses were conducted by SAS 9.4 software.Results:A total of 5 756 and 5 263 samples of HBsAg and anti-HBs were successfully tested, respectively. Comparing the results of HBsAg and anti-HBs from grassroots medical institutions with the results from the third platform, the agreement of HBsAg and anti-HBs was 97.13% and 77.33%, respectively. The Kappa value was 0.56 (95% CI 0.50-0.62) for HBsAg and 0.54 (95% CI 0.52-0.56) for anti-HBs, respectively; and the McNemar tests indicated the difference between the results (all P<0.01). There were also significant differences in agreement of testing results with the third platformin among different regions ( P<0.05 or <0.01). The Kappa values indicated that Jiangsu province and Guangdong province had high accordance rates of HBsAg (0.87 and 0.81, respectively), and Gansu province and Guangdong province had high accordance rates of anti-HBs (Both were 0.74). Regarding the results from the third platform as the standard, the sensitivity of HBsAg testing in grassroots medical institutions was moderate (40.51%) and the specificity was well (99.96%). The sensitivity of anti-HBs testing was substantial (73.18%) and the specificity was well (84.31%). Guangdong province (Youden index: 0.69) and Jiangsu province (Youden index: 0.80) had high identification ability for HBsAg, and for indicator of anti-HBs, Gansu province (Youden index: 0.78) and Guangdong province (Youden index: 0.76) had high identification ability. Conclusion:There are certain differences in results of HBV serological markers tests between the grassroots medical institutions in the demonstration areas of infectious diseases and the third platform. Current testing strategies in grassroots medical institutions are suitable for identifying people without hepatitis B infection, while it is necessary to pay attention to the situation of potential false negative error.