OBJECTIVE To observe the effect of electroacupuncture(EA)preconditioning at Tianshu(ST25)and Neiguan(PC6)on cardiac function and UCP1/BMP3b signaling pathway in brown adipose tissue(BAT)in mice with acute myocardial infarc-tion(AMI),so as to explore the potential mechanism of EA at different acupoints in improving myocardial infarction.METHODS Healthy adult mice and BAT excision mice were selected as the research objects,and they were divided into sham operation group,model group,PC6 group,and ST25 group.After one week of adaptive feeding,the mice in the intervention group were pretreated with bilateral EA at PC6 or ST25 for 20 minutes,respectively,and the AMI model was established by ligating the left anterior descending branch of the coronary artery.In the BAT resection group,BAT resection of the scapular region was performed before EA,and the rest of the intervention remained the same as before.Echocardiography was used to detect the changes in cardiac function.TTC staining was used to observe the myocardial infarct size.ELISA was used to detect the serum levels of cTnT and BMP3b in each group.The qPCR was used to detect the relative expression of β3-AR,UCP1 and BMP3b mRNA in mouse BAT.The protein expression of BMP3b in BAT and p-Smad1/5 in the heart were detected by Western blot.RESULTS Compared with the sham operation group,the left ven-tricular EF and FS of the model group mice were decreased(P<0.001),the white infarct area was increased(P<0.001),the cTnT level in serum was increased(P<0.001),the mRNA expression levels of β3-AR,UCP1,and BMP3b in BAT were increased(P<0.05,P<0.01),and the protein expression of BMP3b was increased(P<0.01).The BMP3b content in serum was increased(P<0.001),and the protein expression of p-Smad1/5 in the heart was increased(P<0.01).Compared with the model group,the left ventricular EF and FS of mice in the ST25 and PC6 group were increased(P<0.001),the area of white infarction was reduced(P<0.001),and the cTnT level in serum was decreased(P<0.05,P<0.01).The mRNA contents of β3-AR,UCP1,and BMP3b in BAT of the ST25 group were significantly increased(P<0.05,P<0.01,P<0.001),the protein expression of BMP3b was increased(P<0.01),and the protein expression of p-Smad1/5 in the heart was increased(P<0.01),while there was no significant change in the PC6 group.After BAT resection,compared with the model group,the left ventricular EF and FS of the mice in the PC6 group were increased(P<0.001),the area of white infarction was reduced(P<0.001),and the cTnT in serum was decreased(P<0.001),while there was no significant change in the ST25 group;there was no significant change in the protein expression of p-Smad1/5 in the heart and the BMP3b content in the serum of the PC6 and ST25 groups.CONCLUSION EA pretreatment at either ST25 or PC6 acupoints can produce myocardial protective effects.The protective effect of ST25 may be through influencing the UCP1/BMP3b signaling path-way in BAT,while PC6 does not depend on this pathway.

Objective To explore the risk factors and possible preventive measures of delayed postoperative intestinal paralysis(PPOI)in elderly(aged ≥75 years)patients with colorectal cancer.Methods This retrospective study included 333 patients with CRC who underwent laporascopic resection in General Department of Beijing Chaoyang Hospital from June 2016 to August 2023.There were 126 patients were enrolled in PPOI group and 207 patients were enrolled in non-PPOI group.The perioperative clinical characteristics of the patients were compared between PPOI group and non-PPOI group,and the risk factors of PPOI and potential preventive measures for them were investigated usingLogisticregression.Results The incidence of PPOI after laparoscopic surgery in elderly patients with colorectal cancer was 37.84％.The ages of the PPOI group and the non-PPOI group were(82.60±3.587)years and(80.38±3.847)years respectively.The rates of primary enterostomy during the operation were 20.63％and 9.66％,respectively,and the preoperative combined nutritional risks were 53.97％and 20.77％,respectively.The preoperative serum albumin levels were lower,which were(35.32±3.77)g/L and(38.36±3.91)g/L,respectively,and the preoperative hemoglobin levels were(104.47±20.31)g/L and(110.33±20.27)g/L,respectively.The intraoperative blood loss was(140.48±130.65)mland(98.26±56.45)ml,respectively.The patients who received enhanced recovery after surgery(ERAS)measures during the perioperative period were 14.29％and 75.85％,respectively.There was a statistically significant difference between the two groups(P＜0.05).The Logistic analysis showed that the risk factors for elderly patients with PPOI including increased age,preoperative nutritional risk,low preoperative albumin,increased intraoperative blood loss.Moreover,the implementation of ERAS protocols including preoperative nutritional support,multimodal low-opioid anesthesia,gastric tube removal and ground activity early after surgery may be the protective factors of PPOI.Conclusion The risk factors of PPOI for colorectal patients older than 75 years including increased age,preoperative nutritional risk,low preoperative albumin,increased intraoperative blood loss.The ERAS protocols including preoperative nutritional support,multimodal low-opioid anesthesia,gastric tube removal and ground activity early after surgery may be useful to prevent the occurrence of PPOI for elderly patients with colorectal cancer.

OBJECTIVE To observe the effect of electroacupuncture(EA)preconditioning at Tianshu(ST25)and Neiguan(PC6)on cardiac function and UCP1/BMP3b signaling pathway in brown adipose tissue(BAT)in mice with acute myocardial infarc-tion(AMI),so as to explore the potential mechanism of EA at different acupoints in improving myocardial infarction.METHODS Healthy adult mice and BAT excision mice were selected as the research objects,and they were divided into sham operation group,model group,PC6 group,and ST25 group.After one week of adaptive feeding,the mice in the intervention group were pretreated with bilateral EA at PC6 or ST25 for 20 minutes,respectively,and the AMI model was established by ligating the left anterior descending branch of the coronary artery.In the BAT resection group,BAT resection of the scapular region was performed before EA,and the rest of the intervention remained the same as before.Echocardiography was used to detect the changes in cardiac function.TTC staining was used to observe the myocardial infarct size.ELISA was used to detect the serum levels of cTnT and BMP3b in each group.The qPCR was used to detect the relative expression of β3-AR,UCP1 and BMP3b mRNA in mouse BAT.The protein expression of BMP3b in BAT and p-Smad1/5 in the heart were detected by Western blot.RESULTS Compared with the sham operation group,the left ven-tricular EF and FS of the model group mice were decreased(P<0.001),the white infarct area was increased(P<0.001),the cTnT level in serum was increased(P<0.001),the mRNA expression levels of β3-AR,UCP1,and BMP3b in BAT were increased(P<0.05,P<0.01),and the protein expression of BMP3b was increased(P<0.01).The BMP3b content in serum was increased(P<0.001),and the protein expression of p-Smad1/5 in the heart was increased(P<0.01).Compared with the model group,the left ventricular EF and FS of mice in the ST25 and PC6 group were increased(P<0.001),the area of white infarction was reduced(P<0.001),and the cTnT level in serum was decreased(P<0.05,P<0.01).The mRNA contents of β3-AR,UCP1,and BMP3b in BAT of the ST25 group were significantly increased(P<0.05,P<0.01,P<0.001),the protein expression of BMP3b was increased(P<0.01),and the protein expression of p-Smad1/5 in the heart was increased(P<0.01),while there was no significant change in the PC6 group.After BAT resection,compared with the model group,the left ventricular EF and FS of the mice in the PC6 group were increased(P<0.001),the area of white infarction was reduced(P<0.001),and the cTnT in serum was decreased(P<0.001),while there was no significant change in the ST25 group;there was no significant change in the protein expression of p-Smad1/5 in the heart and the BMP3b content in the serum of the PC6 and ST25 groups.CONCLUSION EA pretreatment at either ST25 or PC6 acupoints can produce myocardial protective effects.The protective effect of ST25 may be through influencing the UCP1/BMP3b signaling path-way in BAT,while PC6 does not depend on this pathway.

Objective To explore the risk factors and possible preventive measures of delayed postoperative intestinal paralysis(PPOI)in elderly(aged ≥75 years)patients with colorectal cancer.Methods This retrospective study included 333 patients with CRC who underwent laporascopic resection in General Department of Beijing Chaoyang Hospital from June 2016 to August 2023.There were 126 patients were enrolled in PPOI group and 207 patients were enrolled in non-PPOI group.The perioperative clinical characteristics of the patients were compared between PPOI group and non-PPOI group,and the risk factors of PPOI and potential preventive measures for them were investigated usingLogisticregression.Results The incidence of PPOI after laparoscopic surgery in elderly patients with colorectal cancer was 37.84％.The ages of the PPOI group and the non-PPOI group were(82.60±3.587)years and(80.38±3.847)years respectively.The rates of primary enterostomy during the operation were 20.63％and 9.66％,respectively,and the preoperative combined nutritional risks were 53.97％and 20.77％,respectively.The preoperative serum albumin levels were lower,which were(35.32±3.77)g/L and(38.36±3.91)g/L,respectively,and the preoperative hemoglobin levels were(104.47±20.31)g/L and(110.33±20.27)g/L,respectively.The intraoperative blood loss was(140.48±130.65)mland(98.26±56.45)ml,respectively.The patients who received enhanced recovery after surgery(ERAS)measures during the perioperative period were 14.29％and 75.85％,respectively.There was a statistically significant difference between the two groups(P＜0.05).The Logistic analysis showed that the risk factors for elderly patients with PPOI including increased age,preoperative nutritional risk,low preoperative albumin,increased intraoperative blood loss.Moreover,the implementation of ERAS protocols including preoperative nutritional support,multimodal low-opioid anesthesia,gastric tube removal and ground activity early after surgery may be the protective factors of PPOI.Conclusion The risk factors of PPOI for colorectal patients older than 75 years including increased age,preoperative nutritional risk,low preoperative albumin,increased intraoperative blood loss.The ERAS protocols including preoperative nutritional support,multimodal low-opioid anesthesia,gastric tube removal and ground activity early after surgery may be useful to prevent the occurrence of PPOI for elderly patients with colorectal cancer.

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 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 investigate the prevalence and risk factors of multi-site work-related musculoskeletal disorders(WMSDs) among workers in the industry of electronic equipment manufacturing. METHODS: A total of 815 workers in three factories of electronic equipment manufacturing in Guangdong Province were selected as study subjects by convenience sampling. The prevalence of multi-site WMSDs in the past year was investigated using Musculoskeletal Disorders Investigating Questionnaire and the influencing factors were analyzed. RESULTS: The total prevalence of WMSDs was 69.4%(566/815). The prevalence of multi-site WMSDs was 54.5%(444/815), and the prevalence of one-site WMSDs was 15.0%(122/815). Multiple logistic regression showed that female workers had higher prevalence of multi-site WMSDs than males [odds radio(OR) and 95% confidence interval(CI): 1.59(1.12-2.26), P<0.05]. The prevalence of multi-site WMSDs in left-handed workers was lower than that of right-handed workers [OR(95% CI): 0.42(0.19-0.91), P<0.05]. The longer service of current position and the more neck forward movement, the higher prevalence of multi-site WMSDs [OR(95% CI) were 1.33(1.09-1.63) and 1.62(1.23-2.15), P<0.01]. The workers who had long-time sitting at work, adopted uncomfortable working posture, could decide when to work on their own, kept head down for a long time, or often bending wrists up/down had higher prevalence of multi-site WMSDs [OR(95% CI) were 1.41(1.16-1.73), 1.82(1.40-2.38), 1.79(1.16-2.75), 1.92(1.38-2.69) and 1.60(1.14-2.24), respectively, P<0.01]. The workers who could take turns with colleagues to finish work or had enough rest time had lower prevalence of multi-site WMSDs [OR(95% CI): 0.57(0.41-0.78) and 0.67(0.48-0.92), P<0.05]. The workers who worked >10 h per day had lower prevalence of multi-site WMSDs than those who worked ≤8 h per day [OR(95% CI): 0.57(0.37-0.87), P<0.05]. CONCLUSION: Multi-site WMSDs were more common than one-site WMSDs among workers in the industry of electronic equipment manufacturing, and the prevalence of multi-site WMSDs was high. The risk factors include personal factors, work organization and adverse ergonomic factors.

It is important to bring the principal role of medical students into full play and to develop their learning motivation and enthusiasm in order to obtain the satisfactory teaching effect in the clinical practice of preventive medicine and pediatric dentistry.Methods of timely summing-up,self-evaluation,making assumption and pair combination should be recommended.Cultivation for medical students should focus on the idea for diagnosis and treatment,skill of clinical practice and ability of doctor-patient communication.