Characteristics and influencing factors of hearing loss among noise-exposed workers in a large machinery maintenance enterprise / 环境与职业医学

Background The current increasing trend of new cases of occupational noise-induced deafness indicates that the hearing loss of occupational population has not been effectively controlled in China. It is of great significance to study the characteristics of hearing loss among noise-exposed workers and its related factors. Objective To investigate characteristics and influencing factors of hearing loss among occupational noise-exposed workers in a large machinery maintenance enterprise, and to provide a scientific basis to prevent and control noise-induced hearing loss. Methods A cross-sectional survey was conducted to investigate male Han occupational noise-exposed workers in a large mechanical maintenance enterprise. We acquired demographic characteristics, occupational exposure history, and individual life behavior characteristics of the workers through questionnaires, collected occupational exposure level data from annual occupational disease hazard factor surveillance reports, obtained pure tone hearing threshold test data through occupational health examinations, and estimated individual noise exposure levels using cumulative noise exposure (CNE). According to the results of pure tone air conduction hearing threshold test, the workers were divided into a hearing loss group and a normal hearing group. The chi-square test was employed to compare the occupational exposure characteristics and individual life behavior characteristics between the two groups. Additionally, the trend chi-square test was utilized to analyze the changing trends of age, length of service, CNE, and hearing loss rate within the two groups. The relationship between high-frequency hearing loss in both ears and its related influencing factors was assessed by a multiple logistic regression model. Results The M (P25, P75) of CNE for the 2531 occupational noise-exposed workers was 97.51 (95.39, 99.96) dB(A)·year. The incidence of hearing anomaly, binaural high-frequency hearing anomaly, random ear high-frequency hearing anomaly, binaural low-frequency hearing anomaly, and random ear low-frequency hearing anomaly were 22.48%, 16.59%, 22.13%, 2.77%, and 3.52%, respectively. High-frequency hearing threshold increase was the main reason for hearing anomaly (98.42%). In comparison to the CNE ≤ 97 dB(A)·year group, the 97 dB(A)·year<CNE≤ 100 dB(A)·year group and the CNE>100 dB(A)·year group experienced a 36.4% and 52.3% increase in the risk of bilateral high-frequency hearing loss, respectively. The smoking group exhibited a 43.5% elevated risk of bilateral high-frequency hearing loss when compared to the non-smoking group. Conversely, the group frequently wearing hearing protection equipment demonstrated a 23.6% lower risk of bilateral high-frequency hearing loss in comparison to the group occasionally wearing protective equipment. The data suggested that CNE＞97 dB(A)·year and smoking might be independent risk factors for bilateral high-frequency hearing loss, and frequently wearing hearing protection equipment might be an important protective factor. Conclusion Increased CNE and smoking can elevate the risk of high-frequency hearing loss, while personal hearing protection can effectively reduce the risk of hearing loss.

Analysis on occupational stress status of employees and its influencing factors in pharmaceutical enterprises in Beijing City / 中国职业医学

{L-End}Objective To analyze the current status of occupational stress and its influencing factors among workers in pharmaceutical enterprises in Beijing City. {L-End}Methods A total of 860 employees from six pharmaceutical enterprises in Beijing City were selected as the research subjects using convenience sampling method. The Chinese version of the New Brief Job Stress Questionnaire was used to evaluate the occupational stress, and multiple linear regression analysis was used to analyze the influencing factors of occupational stress. {L-End}Results The detection rate of high occupational stress was 1.40% (12/860). The results of multiple linear regression analysis showed that the workers with higher education level and longer length of service had a higher risk of high occupational stress (all P<0.01). Workers who were satisfied with their jobs had a lower risk of high occupational stress than those who were unsatisfied with their jobs (P<0.01). Workers who were satisfied with life had a significantly lower risk of high occupational stress than those who were unsatisfied with life (P<0.01). {L-End}Conclusion The detection rate of high occupational stress in workers of pharmaceutical enterprises is relatively low. Occupational stress is mainly affected by individual factors such as education level and length of service, and work and life satisfaction. Improving job and life satisfaction is helpful to reduce occupational stress level.

Study on the methods of individual occupational stress examination and assessment for workers in electronic industry / 中国职业医学

{L-End}Objective To explore the suitable methods for individual occupational stress examination and evaluation for workers in China based on the electronics industry. {L-End}Methods A total of 1 164 workers from four electronics enterprises in Beijing City were selected as the research subjects using a convenient sampling method. The Occupational Stress Measurement Scale, which was developed based on the Japanese Brief Job Stress Questionnaire, was used to assess the occupational stress of the research subjects, and test the reliability and validity of the scale. Percentile norms and T-score norms were established, and the T-scores of the three dimensions of stress reaction (psychological reaction and physical symptoms), stress factors, and social support were divided into five stages using the normal distribution method with x¯±0.5 s and x¯±1.5 s, which was used to explore a proposed standard for assessing individual stress levels. {L-End}Results The revised scale consisted of 57 items, which could explain 64.0% of the total variation of occupational stress based on the result of item analysis and exploratory factor analysis. The results of confirmatory factor analysis showed that the model fitted well, with root mean square error of approximation of 0.052, standardized root mean square residual of 0.070, comparative fit index of 0.960, and Tucker-Lewis index of 0.958. The Cronbach's α coefficient of the scale was 0.951, and the Spearman-Brown coefficient was 0.837. Cronbach's α coefficients of the three dimensions ranged from 0.794 to 0.952, and the Spearman-Brown coefficients ranged from 0.737 to 0.850. The scores of the three dimensions of stress reaction, stress factors, and social support were (49.1±13.0), (44.9±7.7), and (18.1±3.6), respectively. Workers in the electronics industry met one of the following items were identified as the high level of occupational stress individuals: i) a score of stress reaction dimension ≥72.0 points; ii) a sum of stress factor and social support dimension scores ≥81.0 points, and a stress reaction dimension score ≥58.0 points. {L-End}Conclusion The Occupational Stress Measurement Scale and the criteria for determining high level of occupational stress can be used to assess the individual occupational stress levels of workers in the electronics industry in China. This method can provide a theoretical basis for the formulation of occupational stress examination and assessment for Chinese workers.

Evaluating the risk assessment method of occupational stress in workplaces / 中国职业医学

{L-End}Objective To study and develop a suitable scale to identify and assess risks of occupational stress in workplaces of enterprises, and to explore the establishment of a workplace occupational stress risk assessment method aimed at guiding enterprises to improve working conditions based on the electronics industry in Beijing City. {L-End}Methods The initial version of the Workplace Occupational Stress Risk Assessment Scale (WOSRAS) was constructed based on literature review and expert evaluation. A total of 1 284 employees from four electronics enterprises in Beijing City were selected as the research subjects using a convenient sampling method. Item analysis and exploratory factor analysis were used to determine the final items of the scale and test its reliability and validity. The method of percentile norms was used to establish risk assessment method for the electronics industry workplace and its stress sources, and the cut-off values of low, medium, high risk was graded by the 50th and 80th percentiles of the total score and the score of each dimension of the risk assessment scale. {L-End}Results i) Based on item analysis and exploratory factor analysis, a WOSRAS consisting of six dimensions and 23 items was constructed, which could explain 63.2% of the total variation of occupational stress. The results of confirmatory factor analysis showed that the root mean square error of approximation and standardized root mean square residual were both <0.080, and the comparative fit index and Tucker-Lewis index were both >0.900. The total criterion validity of the scale was 0.816. The total Cronbach's α coefficient of the scale was 0.835, and the Spearman-Brown coefficient was 0.802. ii) The cut-off values of WOSRAS scores for high, medium and low risk in electronics industry were <53.0, 53.0-60.0 and >60.0,respectively. According to the result, the workplace stress risk levels of the production, research and development, and logistics departments of the electronics industry in Beijing were medium risk, while the management department was low risk. {L-End}Conclusion The WOSRAS constructed in this study has good reliability and validity. The proposed risk assessment method can reflect the actual risk status of enterprises in the electronic industry and is convenient for widespread application.

Technique optimization of intravenous or intraperitoneal injection of Evans blue combined with retinal preparations in mice / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To optimize the technique of intravenous injection of Evans blue and retinal preparations in mice, improving the accuracy and repeatability of staining experiment of retinal preparations.METHODS: C57BL/6 male mice were intravenous injected with 10g/L(1%)Evans Blue 0.3mL and circulated in vivo for 10 or 20min, and the eyes were removed after sacrificed and fixed in 4% paraformaldehyde for 20, 40 or 60min. When failure of intravenous injection, the experiment was remediated by intraperitoneal injection of 1% Evans Blue 0.3mL, circulated in vivo for 3h and fixed for 60min to observe morphology, distribution and leakage of the retinal vessels. Besides, we compared the morphology, distribution and leakage of the retinal vessels after intravenous injection with those after intraperitoneal injection to determine the optimal conditions for in vivo circulation time and retinal preparations.RESULTS: After intravenous injection, compared to the retinal vascular condition under 20min in vivo circulation time of Evans blue and 20 or 40min of fixation, with 10min of in vivo Evans blue circulation and 60min of fixation, the morphology of retinal vascular was more intact with less retinal vascular leakage, and the vascular branches are clear. When intravenous injection failed, remediated results from intraperitoneal injection showed that the morphology and distribution of retinal vessels were intact. There was no significant difference in morphology, distribution and leakage of the retinal vessels after 3h of intraperitoneal Evans blue circulation compared to 10min intravenous Evans blue circulation.CONCLUSION: This experiment optimizes the protocol, improves the accuracy and reproducibility of retinal preparations, and provides a reference for the study of related retinal vascular diseases.

Job burnout and influencing factors among Chinese manufacturing employees / 环境与职业医学

Background Manufacturing industry is the main body of China's national economy, and manufacturing employees provide solid guarantee and support for the vigorous development of China's manufacturing industry. The research on job burnout of manufacturing employees is helpful to prevent or alleviate the health damage and economic loss caused by job burnout. Objective To investigate the status and influencing factors of job burnout among manufacturing employees in China, and evaluate the potential mediating effect of job burnout between job stress and depressive symptoms. Methods A cross-sectional study was performed from August to October 2019 and from June to September 2020 in seven provinces of China. Study participants were recruited from 21 manufacturing companies covering 11 manufacturing subdivisions using multistage stratified cluster sampling. General Burnout Scale, Core Occupational Stress Scale, and Patient Health Questionnaire-9 were used to evaluate job burnout, job stress, and depressive symptoms. Mann-Whitney U test and Kruskal-Wallis H test were used to compare data between two independent samples and multiple independent samples of measurement data; Pearson χ2 test was used to compare the rate of enumeration data; Spearman rank correlation analysis was used to evaluate correlation between selected variables; binary logistic regression was used for multivariate analysis; stepwise regression and bias-corrected Bootstrap method were used to test potential mediating effect. Results A total of 10973 valid questionnaires were collected. The M (P25, P75) scores of exhaustions, cynicism, professional efficacy, job burnout, job stress, and depressive symptoms were 1.6 (0.4, 3.0), 1.0 (0.2, 2.2), 4.8 (3.2, 5.7), 1.6 (0.8, 2.5), 45.0 (40.0, 50.0), and 7.0 (4.0, 11.0), respectively. The positive rates of job burnout, job stress, and depressive symptoms were 53.4% (5865/10973), 28.4% (3116/10973), and 29.4% (3231/10973), respectively. The influencing factors of job burnout were gender (versus male; OR for female=0.852), age (versus≤25 years old; ORs for 26-30, 31-40, 41-50, 51-60 years old=0.824, 0.819, 0.738, 0.677), education level (versus junior high school or below; ORs for senior high school/technical secondary school, junior college/vocational college, graduate school or above=1.119, 1.345, 1.331), income per month (versus＜3000 yuan; ORs for 3000-4999, 5000-6999, 7000-8999, 9000-10999, ≥11000 yuan=0.513, 0.470, 0.430, 0.375, 0.411), position (versus assembly line; OR for non-assembly line=0.814), average weekly working hours (versus ≤40 h; ORs for 61-70, ＞70 h=1.199, 1.519), and drinking (versus non-drinking; OR for drinking=1.261). Job burnout was positively correlated with job stress and depressive symptoms (r=0.556, 0.508, P<0.001). Job burnout played a partial mediating role between job stress and depressive symptoms, and its contribution value accounted for 63.2% of the total effect. Conclusion Manufacturing industry employees' job burnout problem is prominent in China, and there are many factors affecting job burnout. Job burnout may play a partial mediating role between job stress and depressive symptoms in the target group.

Five profiles and influencing factors of burnout-engagement continuum in working populations of China / 环境与职业医学

Background With the rise and deepening of positive psychology research, theoretical research on job burnout is also deepening worldwide, and some new theoretical models are proposed, such as the burnout-engagement continuum, but there is still a lack of empirical research and application in China. Objective To analyze the current situation and influencing factors of five profiles in the burnout-engagement continuum in working populations of China: job engagement, ineffective, overextended, disengaged, and burnout. Methods From August to October 2019 and June to September 2020, a total of 27344 subjects of key occupations in six typical industries, including teachers, firefighters, manufacturing workers, medical staff, flight attendants, and traffic police, were selected from 10 provinces (cities) in the eastern, middle, and western regions of China by multistage stratified cluster sampling method for cross-sectional investigation. Maslach Burnout Inventory-General Survey and Core Occupational Stress Scale were used to evaluate job burnout and occupational stress respectively. χ2 test was used to compare rates of count data. Binary logistic regression was used for multivariate analysis of the five profiles. Results Among the subjects, 24.4%, 61.9%, 31.9%, 12.7%, and 11.8% were the prevalence rates of job engagement, ineffective, overextended, disengaged, and burnout, respectively. Flight attendants (35.7%), firefighters (29.0%), traffic police (28.5%), and manufacturing workers (26.5%) had high prevalence rates of job engagement profile. Medical stuff (62.9%) and manufacturing workers (61.8%) had high prevalence rates of ineffective profile. Teachers (39.2%), traffic police (37.2%), and medical stuff (35.5%) had high prevalence rates of overextended profile. Traffic police (17.9%), medical staff (14.3%), and teachers (13.4%) had high prevalence rates of disengaged profile. Traffic police (16.9%), medical staff (13.4%), and teachers (13.3%) had high prevalence rates of burnout profile. The results of multivariate analysis showed that gender, age, education level, marital status, weekly working hours, length of service, income per month, shift work, smoking, drinking, industry, and occupational stress entered into the regression equations of job engagement, ineffective, overextended, disengaged, and burnout. The risks of overextended (OR=1.456-2.970), disengaged (OR=1.306-4.092), and burnout (OR=1.302-4.102) among the high rating groups of the four factors of occupational stress were higher than those among the low rating groups. Flight attendants (OR=0.296) and firefighters (OR=0.329) had lower risks of burnout than teachers, and flight attendants (OR=0.392) and firefighters (OR=0.466) had lower risks of disengaged than teachers. Conclusion Among the prevalence rates of the five profiles in the burnout-engagement continuum in the 6 typical occupational populations in China, ineffective profile is the highest, followed by overextended, and burnout is the lowest. Gender, age, education level, marital status, weekly working hours, length of service, income per month, shift work, smoking, drinking, industry, and occupational stress have different effects on the five profiles, but industry and occupational stress have greater impacts on job burnout.

Study on criteria for selection of general practice doctoral supervisors / 中华全科医师杂志

Objective:To explore the criteria of general practice doctoral supervisors.Methods:The expert consultation questionnaire was formed by literature analysis. Experts in the field of general medicine from universities and tertiary hospitals in Shanghai were invited to participate in two rounds of Delphi consultation. The consultation content included the basic requirements and the importance evaluation of the selection criteria for general practice doctoral supervisors. Descriptive analysis and Analytic Hierarchy Process (AHP) were used to analyze the results of the study.Results:A total of 29 experts participated in the consultation, all with senior professional titles and doctoral degrees. The positive coefficient and expert authority coefficient of the two rounds of expert consultation were 1.0 and 0.925, respectively. The Kendall coordination coefficient of indicator importance evaluation were 0.436 and 0.397, respectively. The ethics, age, professional title, educational background and academic degree and diploma were considered to be included in the basic qualifications. The optimal standards for supervisor selection included teaching ability, scientific research ability, student training and team promotion ability that subdivided into 13 evaluation indexes.Conclusion:The basic qualifications and optimal standards for general practice doctoral supervisors have been preliminarily developed, which provides reference for selection of qualified general practice doctoral supervisors.

The enlightenment of German genral physician training system on the clinical education of community general practitioners in China / 中华医学教育探索杂志

German family physicians practice independently in clinics, and provide primary health care services. General practitioners are a type of specialists. The basis for the self-management of German doctors is the homogeneous medical education in Germany. The new round of medical education reform emphasizes the theory and practical training throughout the entire process of medical education. All medical students in Germany need to go to the clinic for internship and be familiar with primary health care models. Post-graduation education sets rotation plans and assessment standards according to the characteristics of general practice specialties, emphasizes the clinical practice time in the clinics, and urges doctors to continue medical education through the payment of medical insurance. This article draws on the German general practitioner training model, proposes to strengthen the enlightenment of general practice education during the education of undergraduate medical colleges, and strengthen the clinical practice of general practitioners and the construction of general practice training bases, as well as improve the ability of the community physician faculties, in order to provide a reference for the training of general practitioners in China.

Effect of blended teaching method in epidemiology teaching for students in clinical medicine / 上海预防医学

ObjectiveTo determine the effect of blended teaching method in epidemiology teaching for students in clinical medicine. MethodsA total of 143 students in clinical medicine at Tongji University School of Medicine in the fall semester of 2021‒2022 were enrolled in the study. A self-assessment questionnaire was used to assess the satisfaction and recognition on the blended teaching method in epidemiology. ResultsIn terms of teaching effect， 84.6% of the students obtained excellent and good grades in the final evaluation， while 7.0% of the students did not pass the final exam. Approximately 21.0% of the students had difficulties in understanding the concept of bias and its control. The 90.2% were satisfied with the design of the blended teaching method， 84.2% were satisfied with the online video courses， and 60.9% completed more than 75.0% of the online learning resources before class. Additionally， 80.5% of the students responded that they could master the knowledge of epidemiology， and 81.2% considered that the blended teaching method may facilitate personalized learning and they could learn more knowledge of epidemiology. ConclusionBlended teaching method attains remarkable achievements in epidemiology teaching. However， curriculum design， teaching effect， and acceptance may be further strengthened.

Comparative analysis of work-related musculoskeletal disorders catalogues / 中华劳动卫生职业病杂志

Work-related musculoskeletal disorders (WMSDs) refer to musculoskeletal disorders caused by work or work as the main cause, which are characterized by high prevalence and heavy burden of disease as a global problem. The classification and catalog of occupational diseases is of great significance for guiding the prevention and control of occupational diseases and safeguarding the rights and interests of workers. The types of WMSDs included in the list of occupational diseases vary greatly from country to country, and the regulations on specific pathogenic factors are also inconsistent. By sorting out and analyzing the lists and characteristics of WMSDs at home and abroad, and using the International Statistical Classification of Diseases and Related Health Problems (ICD-10) in occupational health to standardize of WMSDs in various countries, which would lay the foundation for future multi-country WMSDs occupational health registration and disease burden research, and provide a reference for China to revise the WMSDs list.

Relationship between pesticide exposure and lipid metabolism in population / 中华劳动卫生职业病杂志

Objective: To investigate the effect of pesticides and herbicides on lipid metabolism. Methods: In November 2020, Based on the data of the national health and Nutrition Survey (NHANES) (2011-2014) , select the population aged 20~65 who have demographic information, pesticide use and data of four lipid metabolism indicators [total cholesterol (TC) , triglyceride (TG) , high density lipoprotein cholesterol (HDLC) and low density lipoprotein cholesterol (LDLC) ] (n=3039) . The subjects were divided into insecticide group (320 people) and non insecticide group (2719) according to the use of insecticides, and herbicide group (156 people) and non herbicide group according to the use of herbicides. Results: Among the 3039 subjects, the males and female were 1509 (49.7%) and 1530 (50.3%) respectively. The males age was (39.7±12.0) years and the females age was (40.2±12.0) years The concentration of HDLC in the NHANES (55.4±15.0) mg/dl was lower than that of (58.2±14.2) mg/dL in the non herbicide group (P<0.05) (b=-0.044, P<0.05) . The results showed that the use of herbicides was related to the decrease of HDLC and the increase of LDLC and LDLC/HDLC in female population (b=-0.050, 0.062, 0.067, all P<0.05) . Conclusion: Herbicide exposure can cause the change of lipid metabolism, and the effect on female population is more obvious.

Adaptive response of A549 cell apoptosis induced by low-dose X-ray irradiation / 中国辐射卫生

Objective@#To study the adaptive response and time effect of A549 cell apoptosis induced by low-dose X-ray irradiation, and to preliminarily explore the possible mechanism of adaptive effect. @*Methods@#A549 cells were irradiated with X-ray of 50 mGy, 200 mGy and 500 mGy, respectively, and then irradiated with an effect dose of 20 Gy after intervals of 3 h, 6 h, 12 h, 24 h and 48 h, respectively, for cell apoptosis detection. The cell cycle distribution and DNA damage were detected after an interval of 6 h between the initial dose and the effect dose. 20 Gy and 0 Gy were set as the control.@*Results@#After irradiation at 20 Gy at intervals of 3 h, 6 h, 12 h and 24 h from the low- dose irradiation, the apoptosis rates of the 50 mGy～20 Gy, 200 mGy～20 Gy, and 500 mGy~ 20 Gy groups were significantly lower than that of the 20 Gy group (P < 0.05); after an interval of 48 h, there was no significant difference in the apoptosis rate between the 50 mGy～20 Gy, 200 mGy～20 Gy, and 500 mGy～20 Gy groups and the 20 Gy group. After an interval of 6 h between the low-dose irradiation and the effect dose irradiation, the percentage of cells at G0/G1 phase in the 50 mGy～20 Gy and 200 mGy～20 Gy groups was significantly lower than that in the 20 Gy group (P < 0.05); the percentage of cells at G2/M phase in the 50 mGy～20 Gy and 200 mGy~20 Gy groups were significantly reduced compared with the 20 Gy group (P < 0.05). There was no significant difference in the percentage of cells at G0/G1 and G2/M phases between the 500 mGy～20 Gy and 20 Gy groups. Compared with the 20 Gy group, the cell DNA damage in the 50 mGy～20 Gy, 200 mGy～20 Gy and 500 mGy~20 Gy groups were decreased, but without significant difference. @*Conclusion@#Low-dose X-ray irradiation can induce the adaptive response of A549 cells apoptosis, which is related to the time interval between the initial dose and the effect dose. The adaptive effect may be related to the changes in cell cycle induced by low-dose X-ray.

Risk factors associated with hypoglycemia in patients with type 2 diabetes mellitus： a community based case-control study / 上海预防医学

ObjectiveTo determine the risk factors associated with hypoglycemia in community patients with type 2 diabetes mellitus（T2DM）. MethodsA case-control study was performed among 914 patients with T2DM and no medical history of hypoglycemia were selected in the Diabetes Unit of Tongji University School of Medicine Affiliated Anting Community Health Center in 2018. A total of 196 patients with T2DM who had ≥1 hypoglycemia event in the past 12 months were presented as the case group， and 718 patients who did not have any hypoglycemia event during the same period were included as the control group. Medical history， medication， life style， and related factors were collected. Multivariate logistic regression analysis was used to determine the risk factors associated with hypoglycemia. ResultsHistory of coronary heart disease ［adjusted odds ratio（aOR）=2.077， 95% CI： 1.293-3.337］， renal disease （aOR=4.775， 95% CI： 1.537-14.830）， and previous insulin use （aOR =1.765， 95%CI： 1.147-2.716） significantly increased the risk of hypoglycemia， while angiotensin converting enzyme inhibitors（ACEI）（aOR =0.127， 95%CI： 0.044-0.366） and β-receptor blockers （aOR =0.271， 95%CI： 0.119-0.616） decreased the risk of hypoglycemia among diabetic patients. ConclusionIncidence of hypoglycemia in community patients with diabetes is high. History of coronary heart disease and kidney disease， and previous insulin use may increase the risk of hypoglycemia， which warrants further attention by community general practitioners.

Study on training requirements of doctoral candidates in general practice / 中华全科医师杂志

Objective:To survey the training requirements for doctoral candidates in general practice.Methods:A questionnaire survey was conducted to investigate the requirements for general practice doctorate training; the items included the training target, training objectives and training contents. A total of 130 stakeholders of general practice participated in the survey, including administrators in health committees, general practice educators of medical schools, general practitioners in hospital and community health service centers and students in general medicine. The participants were divided into training unit group ( n=42), employer group ( n=42) and doctor and student group ( n=46). Results:Among all training objectives, the training "general medicine scientific research ability" ranked the first (121, 93.1%); while 114 (87.7%) respondents believed that the training target should be the leading talents in general medicine. Regarding the content of clinical competence training, 86 (66.1%) respondents believed that there was a lack of medical care training for whole life-cycle and whole population currently. The training requirement for acute disease management and referral competence in employer group was significantly higher than the training unit group (χ2=25.73, P<0.01) and the doctor and student group (χ2=24.37, P<0.01). Most survey respondents believed that the doctorate candidates in general medicine should focus on scientific research training in community clinical medicine ( n=110, 84.6%), community preventive medicine and epidemiology ( n=114, 87.7%); 117 (90.0%) respondents believed that clinical research design and methodology training should be strengthened, and 125 (96.2%) respondents believed that clinical teaching thinking training should be strengthened; 108 (83.1%) survey respondents believed that it is necessary for their units to recruit personnel with doctoral degree in general medicine. Conclusion:The training of doctorate candidates in general medicine should aim at cultivating leading talents in general medicine, strengthen the training of clinical scientific research capabilities, and focus on cultivating their comprehensive abilities of "being able to research, be good at teaching, and understand management", so that they can truly become the leaders in this discipline.

Relationships between solar greenhouse working and selected blood biochemical indexes of elderly workers / 环境与职业医学

Background The aging of the labor force has become a global trend, and various occupational activities can affect blood biochemical indexes and increase the risk of metabolic diseases. Elderly workers are the main laborers in the solar greenhouse industry, and their blood biochemical indexes need more attention. Objective The purpose of this study is to explore the alternation of selected blood biochemical indexes and provide clues for conducting management programs of metabolic diseases in the elderly solar greenhouse workers. Methods The research subjects of the greenhouse group and the non-greenhouse group were selected from a vegetable production base in Northwest China. The elderly workers were selected from a recruited subjects pool for an earlier project by means of matching and non-matching respectively. The matching conditions were gender (consistent), age (±2 years old), body mass index (BMI) (±1 kg·m−2), education level (±1 level), smoking (consistent), and drinking (consistent). Routine clinical tests were used to detect serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), fasting blood glucose (GLU), and albumin (ALB), and single-factor and multi-factor analyse were used to identify different indexes in matching and non-matching samples, respectively. The matching and the non-matching samples included 80 pairs of subjects and 327 subjects, respectively. Results In the matching sample set, the greenhouse group's HDLC [(1.61±0.34) mmol·L−1] was lower than the non-greenhouse group's [(2.09±0.37) mmol·L−1] (P<0.05), the level of TG/HDLC in the greenhouse group was (1.17±0.74), higher than that in the non-greenhouse group (0.78±0.47) (P<0.05), and the level of LDLC/HDLC in the greenhouse group was (1.87±0.36), also higher than that in the non-greenhouse group(P<0.05), while there was no statistical difference of the other indexes between the two groups (all Ps>0.05). In the non-matching sample set, the results of multiple linear regression analysis showed that solar greenhouse working correlated with decreased HDLC, and increased TG/HDLC and LDLC/HDLC among the elderly workers (all Ps<0.05). Conclusion Solar greenhouse working may correlate with variations of selected blood biochemical indexes in elderly workers, and the occupational health surveillance of elderly workers should be strengthened.

Characteristics of blood lipid in solar greenhouse workers / 环境与职业医学

Background As a new type of vegetable production method, solar greenhouse has been widely promoted nationwide. The influence of solar greenhouse working on blood lipid cannot be ignored. Objective The aim of the study is to explore the relationship between solar greenhouse working and blood lipid and family clustering. Methods A total of 744 solar greenhouse workers in northwestern China were selected as the greenhouse group, and 231 general open field farmers in the same area were selected as the non-greenhouse group. The levels of serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) in the two groups were detected. Dyslipidemia was determined by a two-classification criteria in the national guideline of 2007. Multiple logistic regression model and multilevel multiple linear regression model were used to explore the relationship of blood lipid with solar greenhouse working, and its family clustering. Results The number of dyslipidemia cases in the greenhouse group and non-greenhouse group was 142 (19.1%) and 43 (18.6%), respectively, and the difference was not statistically significant (P>0.05). The results of multiple logistic regression analysis showed that increasing age (OR=1.019, 95% CI: 1.001-1.038) and increased BMI (OR=1.162, 95% CI: 1.106-1.220) were related to elevated risk of dyslipidemia (all Ps<0.05). The results of multilevel multiple linear regression model showed that the changes of TC, HDLC, and TG/HDLC had family clustering (b=0.238, 95%CI: 0.132-0.430; b=0.044, 95%CI: 0.033-0.065; b=1.003, 95%CI: 0.947-1.059) (all Ps<0.05). Conclusion Solar greenhouse working does not significantly increase the incidence of dyslipidemia, but the levels of TC, HDLC, and TG/HDLC levels in the solar greenhouse workers have family clusters.

The improvement of micronucleus test method / 公共卫生与预防医学

Objective To simplify and optimize the micronucleus test method. Methods The preparation process of micronucleus test was simplified and optimized. In the improved method, the superfine solution was directly absorbed and discarded after cell culture, and then potassium chloride solution was added for hypotonic treatment. Then pre-fixation, centrifugation. Once the centrifugation was completed, the cells which fixed only once were directly dropped to the slide. Results The background of the slides was clear and the cells were slightly darker, but the observation of cells and micronucleus was not affected. There were a lot of binuclear cells, which can meet the counting requirements. With oil and high magnification, the image wais clearer and the background was cleaner. The cytoplasmic integrity rate, cell stain rate and the average number of cells per high magnification field of cells by the improvement method were significantly increased compared with that by the traditional methods, the probability P values were 0.0051 (χ2=7.8375), 0.0140 (χ2=6.0437) and 0.0025 (t=3.0951), respectively. The rate of micronucleus cells and cells group index had no statistical significance compared with the traditional method, the probability P values were 0.7749 (χ2=0.0817) and 0.5152 (U =0.0000), respectively. Conclusion The new method is more simple, easier to control the test quality, more reliable test results, and save time, manpower and material resources.

Prevalence of heart failure in Chinese cognitive impairment patients： a meta-analysis / 上海预防医学

Objective:Heart failure （HF） and cognitive impairment have become serious medical problems in China. This study used meta-analysis to comprehensively evaluate the prevalence of cognitive impairment in patients with HF in China， and provided suggestions for intervention and prevention of cognitive impairment in this population. Methods:A systematic retrieval was conducted by searching relevant literatures regarding cognitive impairment in Chinese HF patients. These reports were published on CNKI， Wanfang， SinoMed， VIP and PubMed， from January 1， 1980 to July 10， 2020. The Agency for Healthcare Research and Quality （AHRQ） criteria and Newcastle-Ottawa Scale were used to evaluate the literature quality of cross-sectional studies and case-control studies， respectively. Stata16.0 was used for combined prevalence and effect value. Results:A total of 20 articles with medium quality were included. Six of them were case-control studies， with a total sample size of 933 people， and healthy people as controls. The Odds Ratios （OR） value of the prevalence of cognitive impairment in patients with HF was 2.77 （95% CI： 2.05-3.74）. 14 articles were cross-sectional studies with a total sample size of 3000. In China， the prevalence of cognitive impairment in patients with HF was 54.3% （95% CI： 0.43-0.65）. Subgroup analysis showed that the prevalence of cognitive impairment was increased with age， and women had a higher prevalence （58.4%） than that in men （48.4%）. The prevalence in studies using the Montreal Cognitive Assessment （MoCA）to evaluate cognitive impairment （63.6%） was higher than those using Mini-mental State Examination （MMSE）（41.7%）. The limitations of this study include the following： only used the relevant literature on cognitive impairment in patients with HF in China； failed to explain the source of heterogeneity， unable to determine the impact of the study area on heterogeneity， and unable to determine the causality of HF and cognitive impairment. Conclusion:The prevalence of cognitive impairment in patients with HF in China is high and significantly affected by age， gender and other factors. Appropriate measures should be taken for prevention and timely intervention.

Advancement of Cancer Associated Fibroblasts-derived Exosomes in Lung Cancer / 中国肺癌杂志

Tumor microenvironment (TME) is a dynamic network distributed around tumor cells. Cancer-associated fibroblasts (CAFs), as an important component of the TME, are not only closely related to normal fibroblasts, but also can secrete a variety of substances to participate in the regulation of the TME. Exosomes, one of the substances from CAFs, can promote the formation and development of lung cancer, including promoting the formation of TME, increasing pulmonary tumor cell invasion and metastasis, mediating pulmonary tumor immunosuppression and participating in radiotherapy and chemotherapy resistance. This article reviews the current research status and progress of cancer associated fibroblasts-derived exosomes in lung cancer.
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