Objective To prepare recombinant plasminogen activator(Pla) protein in E.coli BL21 cells that can be used in studying interactions between Yersinia pestis proteins and immunologic diagnosis of plague.Methods The pla gene was amplified by PCR and cloned into the pET28a expression vector.E.coli BL21 competent cells were transformed with the recombinant vectors, and isopropyl-β-D-thiogalactopyranoside ( IPTG) was added to induce expression of Pla protein. The expressed protein was detected by SDS-PAGE electrophoresis.The inclusion bodies of Pla protein were denatured in 8 mol/L urea, and then refolded using gradient urea solutions.The purified protein was identified by SDS-PAGE electrophoresis and Western blot.Results and Conclusion The constructed expression vector was demonstrated to be correct through agarose gel electrophoresis and sequencing.The recombinant Pla protein was accumulated as an inclusion body in E.coli, and the overexpression product was mainly a target protein, the yield of which was very high.SDS-PAGE purity of the bioactive Pla protein was obtained by denaturing and refolding the inclusion bodies.This study provides a simple and quick method for highly efficient preparation of biologically active Pla protein.

Objective To establish a simple and quick loop-mediated isothermal amplification (LAMP)method for detection of Yersinia pestis.Methods LAMP Primers were designed based on the specific sequence 3a in Y.pestis chromosome.LAMP reaction results were detected using turbidity meter or visual method.The specificity of the constructed method was evaluated by detecting Y.pestis and its closely-related bacteria.The different dilution DNA template was detected with LAMP and PCR to evaluate the sensitivity of the method.Results Thirty strains of bacteria closely related to Y.pestis were detected by the constructed LAMP,and all the results were negative,indicating that the method had a very high specificity.The detection sensitivity of this LAMP assay was 20 pg of DNA per reaction,which was ten-fold that of the regular PCR.The detection reaction was completed in 25 min.Conclusion This LAMP method is quick,sensitive, specific and simple,which is expecked to become an effective method for rapid detection of Y.pestis on the scene.

Nanopore-based sequencers, as the fourth-generation DNA sequencing technology, have the potential to quickly and reliably sequence the entire human genome for less than $1000, and possibly for even less than$100. The single-molecule techniques used by this technology allow us to further study the interaction between DNA and protein, as well as between protein and protein. Nanopore analysis opens a new door to molecular biology investigation at the single-molecule scale. In this article, we have reviewed academic achievements in nanopore technology from the past as well as the latest advances, including both biological and solid-state nanopores, and discussed their recent and potential applications.

Objective:To investigate public health-related professions' recruit requirements and understand the training scheme for preventive medicine-majored undergraduates in colleges and universities in China.Methods:An online questionnaire was adopted to collect data on the recruit requirements of public health-related professions. Information on the core courses, internship, and practical training for preventive medicine-majored undergraduates was collected through universities' official websites.Results:The employers had a high requirement for education and specific majors. Also, administration professions attached importance to comprehensive quality, while professional positions to professional skills. 47.2% (67/142) employers made Talent Introduction Programs for the next three years. 20.0% (3/15) universities offered all the core courses required by national standards. For internship and practical training, both clinical practice and professional practice's median durations were 16 and 11 weeks, respectively.Conclusion:Employers showed significant demand for public health graduates and having a high requirement for personal ability and comprehensive quality. The universities should improve the setting of core courses and strengthen students' practical ability and overall quality.

Objective:To understand the basic qualities, practitioners will and related influences, of undergraduate, master, and doctoral students majoring in public health (hereinafter referred to as public health students), and explore the influencing factors of practitioners will.Methods:Through the online questionnaire survey, we collected information on the basic qualities of the public health students, their practitioners will and related influencing factors, and their opinions on the current state of public health in China. χ 2 test and multi-factor logistic regression were used to analyze the influencing factors of public health students' willingness to engage in public health related work, and word frequency analysis was used to conduct a descriptive analysis of public health students' views on public health in China. Results:A total of 2 081 pieces of valid information were collected, of which 86.54% (1 801/2 081) of the students in the school chose to engage in public health related work in the future. For public health students, the higher the target after-tax monthly income ( OR=0.345, 95% CI: 0.158-0.751), the lower the willingness to engage in public health related work in the future; Very satisfied with school employment guidance work ( OR=4.072, 95% CI: 1.234-13.436) compared with very dissatisfied, the willingness to engage in public health related work in the future is higher. Conclusion:The willingness of students in public health related majors to engage in public health related majors in China is mainly affected by three factors: payment levels, employment guidance and professional post recognition. It is recommended to appropriately raise the salaries of public health related positions. Strengthening school employment guidance training and professional identity training is conducive to enhancing the willingness of public health students to engage in relevant work in their profession.

Objective:To understand the basic qualities, practitioners will and related influences, of undergraduate, master, and doctoral students majoring in public health (hereinafter referred to as public health students), and explore the influencing factors of practitioners will.Methods:Through the online questionnaire survey, we collected information on the basic qualities of the public health students, their practitioners will and related influencing factors, and their opinions on the current state of public health in China. χ 2 test and multi-factor logistic regression were used to analyze the influencing factors of public health students' willingness to engage in public health related work, and word frequency analysis was used to conduct a descriptive analysis of public health students' views on public health in China. Results:A total of 2 081 pieces of valid information were collected, of which 86.54% (1 801/2 081) of the students in the school chose to engage in public health related work in the future. For public health students, the higher the target after-tax monthly income ( OR=0.345, 95% CI: 0.158-0.751), the lower the willingness to engage in public health related work in the future; Very satisfied with school employment guidance work ( OR=4.072, 95% CI: 1.234-13.436) compared with very dissatisfied, the willingness to engage in public health related work in the future is higher. Conclusion:The willingness of students in public health related majors to engage in public health related majors in China is mainly affected by three factors: payment levels, employment guidance and professional post recognition. It is recommended to appropriately raise the salaries of public health related positions. Strengthening school employment guidance training and professional identity training is conducive to enhancing the willingness of public health students to engage in relevant work in their profession.

Objective:To understand the employment situation of graduates of public health-related majors and explore the associated factors of turnover intention among public health practitioners in China.Methods:In April 2020, the convenient sampling method was used to recruit public health related graduates from 98 universities with public health-related majors from 31 provinces in China (excluding Hong Kong, Macao and Taiwan) and from Chinese Center for Disease Control and Prevention (only including working or unemployed status, no requirement for graduation years). A total of 1 322 questionnaires were collected, of which 1 165 (88.1%) were valid. Through the network questionnaire survey, the information of public health graduates′ work situation, job satisfaction and turnover intention were collected. Multivariate logistic regression model was used to analyze the associated factors of turnover intention, and structural equation model was constructed to explore the correlation between turnover intention and job satisfaction.Results:The age of 1 165 graduates was (28.1 ±4.8) years. Among them, 719 (61.7%) were female and 856 (73.5%) graduates were engaged in public health-related work after graduation. The results of multivariate logistic regression analysis showed that compared with those over 30 years old, graduates under 30 years old had higher turnover intention ( OR=2.531, 95% CI: 1.549-4.155). Compared with those with junior or no title, graduates with senior title had higher turnover intention ( OR=2.310, 95% CI: 1.047-5.162). The results of structural equation model analysis showed that the four factors of job satisfaction, ‘salary and welfare’, ‘promotion development’, ‘work itself’, and ‘internal and external environment’, were negatively correlated with turnover intention. The internal and external environment had the greatest impact on turnover intention (total effect =-0.539). Conclusion:Most graduates of public health-related majors are engaged in public health-related work in China. Age, professional title and job satisfaction are the associated factors of turnover intention.

Objective:To understand the employment situation of graduates of public health-related majors and explore the associated factors of turnover intention among public health practitioners in China.Methods:In April 2020, the convenient sampling method was used to recruit public health related graduates from 98 universities with public health-related majors from 31 provinces in China (excluding Hong Kong, Macao and Taiwan) and from Chinese Center for Disease Control and Prevention (only including working or unemployed status, no requirement for graduation years). A total of 1 322 questionnaires were collected, of which 1 165 (88.1%) were valid. Through the network questionnaire survey, the information of public health graduates′ work situation, job satisfaction and turnover intention were collected. Multivariate logistic regression model was used to analyze the associated factors of turnover intention, and structural equation model was constructed to explore the correlation between turnover intention and job satisfaction.Results:The age of 1 165 graduates was (28.1 ±4.8) years. Among them, 719 (61.7%) were female and 856 (73.5%) graduates were engaged in public health-related work after graduation. The results of multivariate logistic regression analysis showed that compared with those over 30 years old, graduates under 30 years old had higher turnover intention ( OR=2.531, 95% CI: 1.549-4.155). Compared with those with junior or no title, graduates with senior title had higher turnover intention ( OR=2.310, 95% CI: 1.047-5.162). The results of structural equation model analysis showed that the four factors of job satisfaction, ‘salary and welfare’, ‘promotion development’, ‘work itself’, and ‘internal and external environment’, were negatively correlated with turnover intention. The internal and external environment had the greatest impact on turnover intention (total effect =-0.539). Conclusion:Most graduates of public health-related majors are engaged in public health-related work in China. Age, professional title and job satisfaction are the associated factors of turnover intention.