[Status quo regarding the recruit requirements of public health-related employers and training scheme for undergraduates majored in preventive medicine in colleges and universities].

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.

[A survey on the willingness of college students majoring in public health to work in their majors].

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. χ2 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.

[Employment, turnover intention and the associated factors among public health graduates in China].

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.

Patient-derived organoids of non-small cells lung cancer and their application for drug screening.

Patient-derived organoids (PDOs) are emerging as preclinical models with promising values in personalized cancer therapy. The purpose of this study was to establish a living biobank of PDOs from patients with non-small cell lung cancer (NSCLC) and to study the responses of PDOs to drugs. PDOs derived from NSCLC were cultured in vitro, and then treated with natural compounds including chelerythrine chloride, cantharidin, harmine, berberine and betaine with series of concentrations (0.5-30 µM) for drug screening. Phenotypic features and treatment responses of established PDOs were reported. Cell lines (H1299, H460 and H1650) were used for drug screening. We successfully established a living NSCLC organoids biobank of 10 patients, which showed similar pathological features with primary tumors. Nine of the 10 patients showed mutations in EGFR. Natural compounds chelerythrine chloride, cantharidin and harmine showed anticancer activity on PDOs and cell lines. There was no significant difference in the 95% confidence interval (CI) for the IC50 value of chelerythrine chloride between PDOs (1.56-2.88 µM) and cell lines (1.45-3.73 µM, p>0.05). PDOs were sensitive to berberine (95% CI, 0.092-1.55 µM), whereas cell lines showed a resistance (95% CI, 46.57-2275 µM, p<0.0001). PDOs had a higher IC50 value of cantharidin, and a lower IC50 value of harmine than cell lines (p<0.05, 7.50-10.45 µM and 4.27-6.50 µM in PDOs, 3.07-4.44 µM and 4.69-544.99 µM in cell lines, respectively). Both PDOs and cell lines were resistant to betaine. Chelerythrine chloride showed the highest inhibitory effect in both models. Our study established a living biobank of PDOs from NSCLC patients, which might be used for high-throughput drug screening and for promising personalized therapy design.

Body distribution in mice of intravenously injected camptothecin solid lipid nanoparticles and targeting effect on brain.

The objective of the present study was to investigate the specific drug targeting of anticarcinogenic drugs, such as camptothecin (CA), after intravenous (i.v.) injection by incorporation into solid lipid nanoparticles (SLN). A CA loaded SLN suspension consisted of 0.1% (w/w) camptothecin, 2.0% (w/w) stearic acid, 1.5% (w/w) soybean lecithin and 0.5% (w/w) polyoxyethylene-polyoxypropylene copolymer (Poloxamer 188) was prepared by high pressure homogenization. In vitro drug release was investigated in pH 7.4 phosphate-buffered saline at 37 degrees C. The concentrations of camptothecin in various organs were determined using reversed-phase high-performance liquid chromatography with a fluorescence detector after i.v. administration of CA-SLN and a camptothecin control solution (CA-Sol). The results showed that the CA-SLN had an average diameter 196.8 nm with a Zeta potential of -69.3 mV and in vitro drug release was achieved for up to a week. In tested organs, the AUC/dose and the mean residence times (MRT) of CA-SLN were much higher than those of CA-Sol, especially in brain, heart and reticuloendothelial cells containing organs. The brain AUC ratio of CA-SLN to CA-Sol was the highest among the tested organs. These results indicate that SLN are a promising sustained release and drug targeting system for lipophilic antitumour drugs, and may also allow a reduction in dosage and a decrease in systemic toxicity.

[Effect of pulse current iontophoretic transdermal delivery of insulin on blood glucose in diabetic rats].

Iontophoresis of pulse current with various current intensity, frequency, on/off ratio and duration of treatment was used to facilitate the transdermal delivery of insulin in order to control blood glucose levels in diabetic rats. Male Sprague-Dawley rats were made diabetic by i.p. injection of streptozotocin (65 mg . kg-1 body weight). After two days, diabetic rats were anaesthetized with urethane (as 25% aqueous solution, 1.5 mg . g-1). Both the reservoir electrodes and the receptor electrodes were applied on the abdominal site of the diabetic rats. Iontophoresis was carried out using a prototype transdermal periodic iontophoretic system in order to provide the required direct current with desired pulse modes. The extent of reduction of blood glucose levels was found to be positively correlated with the current intensity, frequency and duration of treatment to some extent. But when the current intensity was over 0.8 mA/cm2 and the frequency was over 3000 Hz, the reduction of blood glucose levels did not continuously increase. Blood glucose levels were found to be better controlled when the on/off ratio of 1 : 1 was used.

[Facilitated transdermal delivery of insulin by pulse current iontophoresis].

Facilitated transdermal delivery of insulin by pulse current iontophoresis was investigated. It was found that pulse current iontophoresis can increase the transdermal permeation rate, and there was a positive correlation between reservoir insulin concentration and skin permeation rate of insulin. Moreover, when the reservoir solution pH (3.6) was below the isoelectric point of insulin (pI 5.2), the transdermal permeation rate of insulin was the highest, 324.3 +/- 33.4 microU/(cm2.h). When the pH of the reservoir solution was brought up to 7.4, the transdermal permeation rate of insulin declined markedly to 143.7 +/- 27.3 microU/(cm2.h). When the reservoir solution pH was close to the isoelectric point of insulin, the transdermal permeation rate of insulin was the lowest, 78.4 +/- 21.9 microU/(cm2.h).