Since the examination of doctor's qualifications came into effect, methods that are set by standard to judge whether one passes the examination or not were in dispute all the while. This article is going to introduce four kinds of methods (Angoff method、Modified Angoff method、Nedelsky method、Borderline group method) which are commonly used at home and abroad. Summarizing their advantages, disadvantages and the usage in the process of standards setting in various countries, we aim to provide reference for setting cutoff score of the examination of doctor's qualifications in China.

Objective To understand the present status and explore the influencing factors of quality of life(QOL)among medical students,so as to provide a reference for the improvement of the QOL. Methods A total of 1 898 medical students sampled by stratified cluster sampling method were recruited and investigated by wHO-BREF scale. The influencing factors were assessed by t-test and one-way ANOVA. The data were analyzed by SPSS 19.0. Results Scores of the physical,psychological,social relationship,environmental domain of quality of life were 64.99±13.28,61.85± 13.79,61.58±14.53,and 54.91±13.91,respectively. The results indicated grade,monthly income of family,physical training,quality of sleep and history of trauma were the influencing factors of QOL among medical students,and the differences were all statistically significant(P<0.05). Con?clusion The score of environmental domain of QOL among medical students was the lowest. In order to improve the QOL of medical students, schools should take different measures to them according to different grades or monthly income.

Objective To investigate the anticancer effects and detailed mechanisms of Saikosaponin D (SSD) in human hepatoma HepG2 cells. Methods Cell proliferation and apoptosis were tested by MTT assay and Annexin-V/PI assay respectively. The expressions of CCAAT enhancer binding protein β(C/EBPβ) and p53 were detected by RT-PCR and Western blotting. Results SSD inhibited cell proliferation in a dose-dependent manner and induced apoptosis at the concentration of 5.0mg/L. SSD significantly increased the mRNA and protein levels of C/EBPβ and p53 in a dose-dependent manner. Conclusion SSD exerts its anticancer effect by inhibiting cell proliferation and inducing apoptosis partly through C/EBPβ-p53 signal pathway in HepG2 cells.

Objective To explore the expression of COX-2,PD-ECGF and VEGF in gastric carcinoma tissue,and analyze and identify the relationship between the expression and tumor angiogenesis together with biological behaviour in gastric carcinoma.Methods ElivisionTM immunohistochemical method was performed to detect the expression of COX-2,PD-ECGF,VEGF and CD34,and evaluate the value of MVD in surgically resected gastric carcinoma specimens and biopsy tissues under gastroscope,including normal gastric mucosa tissues, metaplasia tissues and gastric mucosal atypical hyperplasia tissues. Clinicopathologic data of patients were analyzed retrospectively. Results The positive expression of COX-2, PD-ECGF,VEGF and MVD in gastric carcinoma were significantly higher than those in normal gastric mucosa, metaplasia or gastric mucosal atypical hyperplasia,and also their expression and MVD were closely related to lymph node metastasis and depth of invasion. The MVD in the groups of COX-2,PD-ECGF,VEGF positive-expression were significantly higher than those in negative-expression groups respectively. There were positive correlations among the expression of COX-2,PD-ECGF and VEGF in gastric carcinoma. MVD increased significantly when COX-2, PD-ECGF and VEGF coexpressed. Conclusion The expression of COX-2,PD-ECGF,VEGF and tumor angiogenesis participated in the genesis,invasion and metastasis of human gastric carcinoma.COX-2,PD-ECGF and VEGF participated in the tumor angiogenesis of gastric carcinoma. In the process of tumor angiogenesis and expression in gastric carcinoma, COX-2, PD-ECGF and VEGF could strengthen the effectiveness each other.They could strengthen the effective ness of tumor angiogenesis when they coexpressed. They could be selected as targets for tumor anti-angiogenesis treatment.

Objective: To investigate the changes in the composition of intestinal microbiota in mice with acute liver failure and identify characteristic bacteria, and to provide a basis for the diagnosis and treatment of acute liver failure with intestinal microbiota disorders. Methods: A total of 30 specific pathogen-free male BALB/c mice were used in this study, including 25 mice in the model group and 5 mice in the control group. An acute liver failure model was induced by D-galactosamine. Microbial DNA was extracted from intestinal contents in different segments of the lower digestive tract (ileum and colon) and feces and then were amplified using PCR. The regions of 16S V3-V4 were subjected to high-throughput sequencing, followed by bioinformatics analyses, including OTU hierarchical clustering, species annotation, alpha-diversity analysis, and LEfSe (LDA Effect Size) analysis. Comparison of continuous data was made using t-test, while comparison of categorical data was made using χ2 test. Results: A total of 10 mice survived in the two groups, with 80% mortality rate in the model group. The alpha-diversity analysis revealed increased bacterial diversity and abundance in the ileum, increased bacterial diversity and reduced bacterial abundance in the colon, and reduced bacterial diversity and insignificantly changed bacterial abundance in feces in the model group compared with the control group. Based on the optimized classification level, significantly reduced abundance of Clostridiaceae (44.95% ± 19.28% vs 7.51% ± 16.57%, P = 0.011) in the ileum, whereas significantly increased abundance of Rikenellaceae (1.08% ± 1.01% vs 4.18% ± 2.39%, P = 0.028), S24-7 (4.75% ± 4.87% vs 22.77% ± 13.05%, P = 0.020), and F16 (0.24% ± 0.28% vs 2.18% ± 1.61%, P = 0.029) in the colon were found in model group compared with the control group. The LEfSe analysis demonstrated that there were significant differences in Staphylococcaceae and S24-7 between the two groups, and S24-7 could be defined as the characteristic bacteria. Conclusion Intestinal microbiota disorders, especially the excessive growth of microbes in the ileum, are observed in mice with acute liver failure. Moreover, acute liver failure may be closely associated with the excessive growth of S24-7.

Objective: To investigate relationship between sexual behavior and health-risk behavior of college students, and to provide suggestions for sex education in university. Methods: Using stratified cluster sampling and selected 1 585 college students to complete questionnaires in Chongqing University of Arts and Sciences. Results: The sexual behavior rate was 16.1%, energy drinking rate was 39.2%, smoking rate was 18.0%, alcohol drinking rate was 34.8%, gambling rate was 9.2%. There were significant differences between different gender, native place, drinking energy drink, smoking, drinking alcohol, gambling students’ sexual behaviors’ rates(χ2=42.84, 31.11, 40.12, 18.96, 53.66, 70.17, 42.50,P<0.01).The results of multivariate logistic regression showed that, drinking energy drink(OR=0.71, 95%CI=0.53-0.96), somking(OR=0.47, 95%CI=0.33-0.66), drinking alcohol(OR=0.50, 95%CI=0.37-0.69), gambling (OR=0.52, 95%CI=0.35-0.79)was positively associated with sexual behavior of college students(P<0.05). Conclusion The sexual behavior co-occurs with energy drinking, smoking, drinking and gambling; the college should lead students to keep away from health-risk behaviors in sexual education.

Objective To explore the association of ATP-binding cassette (ABC) efflux pump gene Rv1217c-Rv1218c and the drug resistance of Mycobacterium tuberculosis.Methods A total of 34 Mycobacterium tuberculosis clinical isolates including 24 drug-resistance isolates which were resistant to riffampicin,isoniazid,streptomycin or ethambutol and resistant to at least one second-line antituberculosis drug,and 10 drug-sensitive isolates were involved in this study.The RNA of isolated strains was extracted and then reverse transcribed. Gene expression was performed by real-time polymerase chain reaction (PCR) and data was analyzed by t test and Logistic regression analysis.Results The expressions of Rv1217c in rifampicin-resistant group (2.13 ± 1.89,t =3.44,P＜0.01),isoniazid-resistant group ( 1.84 ± 1.86,t =3.16,P＜ 0.05),streptomycin-resistant group ( 1.86 ±1.96,t=2.78,P＜0.05) and ethambutol-resistant groups (3.36±2.35,t=3.04,P＜0.05) were all higher than sensitive isolates (0.42 ± 0.31).The expressions of Rv1218c in rifampicin-resistant group (2.54±1.84,t=3.82,P＜0.01),isoniazid-resistant group (2.34± 1.84,t=3.72,P＜0.01),streptomycin-resistant group (2.15±1.86,t=3.01,P＜0.01) and ethambutol-resistant groups (3.78± 1.78,t=4.22,P＜0.01 ) were all higher than sensitive isolates (0.65 ± 0.42).The expressions of Rv1217c and Rv1218c in multidrug resistant group were 2.74±2.07 and 3.33± 1.77,respectively,which were both higher than polydrug resistant group (0.79 ± 0.47 and 1.03 ± 0.79,respectively; t =2.91,P＜0.05 ; t =3.84,P＜0.01,respectively).Logistic regression analysis found that high Rv1217c expression was positively correlated with rifampicin resistance and negatively correlated with isoniazid resistance (both P＜ 0.01 ),while high Rv1218c expression was negatively correlated with rifampicin resistance and positively correlated with isoniazid resistance (both P＜0.01 ).High expressions of two genes were both positively correlated with ethambutol resistance and multidrug resistance (both P＜0.01 ) and not statistically correlated with streptomycin resistance (P＞0.05).Conclusions The expressions of ABC efflux pump gene,Rv1217c-Rv1218c,are correlated with multiple drug resistance.The overexpression may contribute to the multidrug resistance of Mycobacterium tuberculosis.

【Objective】 To investigate the effect of optimized preoperative hemoglobin (Hb) level on clinical outcome in patients undergoing coronary artery bypass grafting (CABG). 【Methods】 Retrospective analysis was performed on patients who were selected to receive CABG from April 2020 to August 2021 in our hospital. Preoperative basic data, perioperative blood transfusion volume, blood transfusion rate, acute liver function impairment, renal function impairment (AKI), ICU stay, length of hospital stay, and in-hospital mortality of patients, meeting the inclusion criteria, were collected. According to the perioperative red blood cell transfusion, the optimal preoperative Hb threshold was calculated by receiver operating characteristic curve (ROC). According to the threshold, all patients were divided into two groups, and the blood transfusion volume and clinical outcomes of the two groups were compared to evaluate the predictive value of the optimal threshold of Hb. 【Results】 A total of 915 patients who met the inclusion criteria were enrolled in the study. The optimal threshold for predicting red blood cell transfusion rate by calculating preoperative Hb value by ROC curve was 118 g/L for males and 116g/L for females. Group A: Hb≤ threshold (n=293) was divided into the red blood cell transfusion group A1 and the red blood cell non-transfusion group A2. Group B: Hb>threshold (n=622) was divided into the red blood cell non-transfusion group B1 and no red blood cell non-transfusion group B2. The risk factors for perioperative red blood cell transfusion were age (OR=1.033 874, 95%CI 1.000 4-1.068 3, P<0.01), gender (female) (OR=3.268 5, 95%CI 2.353 1-4.540 0, P<0.01), BMI (OR=0.927 8, 95%CI 0.883 3-0.974 4, P<0.01), chronic renal insufficiency (CKD) (OR=2.041 1, 95%CI 1.347 8-3.091 0, P<0.01). Preoperative Hb≤ threshold (OR=3.517 4, 95%CI 2.502 1-4.944 7, P<0.01) was an independent risk factor for perioperative red blood cell transfusion. Perioperative red blood cell transfusion in patients with preoperative anemia further increases the incidence of postoperative complications (acute liver injury, AKI) and length of ICU stay. 【Conclusion】 Preoperative Hb≤ threshold can effectively predict perioperative red blood cell transfusion in patients with CABG, and increase the risk of postoperative acute liver injury, AKI, prolonged ICU stay and hospital stay. Optimizing the preoperative Hb level in CABG patients, increasing the Hb level to 118 g/L in males and 116 g/L in females can reduce the incidence of perioperative red blood cell transfusion and postoperative complications.

Purpose/Significance User portraits of doctors offering free medical advice in online live streaming are constructed and further used to analyze the behavioral characteristics of various types of doctors,so as to provide references for improving the effect of live streaming and their influence.Method/Process A sample of 1 816 doctors who offer free medical advice on the Haodf.com platform is used for clustering analysis to generate different doctor group portraits by using the two-step clustering algorithm.Then an evaluation system for live streaming influence is constructed to explore the differences in online influence among doctors with different styles of live streaming.Result/Conclusion Three types of doctor group portraits are identified,including knowledge-sharing,self-promotional and sociable.There are significant differences in their online influence and three dimensions of live streaming effects including activeness,reputation,and hotness among different doctor groups.Comparative analysis is further performed to find potential solutions for enhancing their live streaming influence.

OBJECTIVE: To compare the occupational health risk assessment results of 3 risk assessment methods in workers exposed to methyl isoamyl ketone(MIAK). METHODS: A rubber antiaging agent manufacturer and its workers in Shandong Province were selected as study subjects. An on-site occupational health survey was conducted and MIAK levels in workplace detected. We chose Romania occupational accidents and occupational disease risk assessment method(hereinafter referred to as “the qualitative assessment method”), Singapore harmful chemicals contact ratio method occupational exposure to risk assessment(hereinafter referred to as the “half-quantitative assessment method”) and the occupational hazards risk index method to conduct occupational health risk assessment for MIAK exposure in workers in the enterprise, and use risk ratio method to compare the results of the 3 different risk assessment methods at the same time. RESULTS: All the results of qualitative assessment method on the risk grade of inspectors, dose inspectors, recovery inspectors in the production workshop, laboratory analysts and warehouse keepers were grade 2. The results of semi-quantitative assessment method on the risk ratio of inspectors, dose inspectors, recovery inspectors in the production workshop were grade 2, while the risk ratios of laboratory analysts and warehouse keepers were grade 1. The assessment result of occupational hazard risk index method on the risk level of inspectors in the production workshop was grade 4, and the assessment results of dose inspectors, recovery inspectors in the production workshop, laboratory analysts and warehouse keepers were grade 3.CONCLUSION: Compared with the qualitative assessment method and the semi-quantitative assessment method, the occupational hazard risk index method has a higher risk ratio of occupational health risk of MIAK and the assessment results were relatively more comprehensive, reasonable and objective.