Object Effectively extracting RNA from Anoectochilus roxburghii (Wall.) Ldl. lays a foundation to research the mechanism of endomycorrhiza promoting its growth. Methods RNA was prepared by CTAB, electrophoresis on 1% agroses gel and photo are taken with MutiImage TM Light Cabinet. Results The ratios of RNA A 260 /A 230 and A 260 /A 280 were 2.054 and 1.818, respectively. And the yield was 154.35 ?g/g fresh. The bands were clear on agrose gel and integrity of RNA was good. Conclusion RNA with high quality and high quantity is isolated by the method of CTAB for medicinal plants with high concentrations of polysaccharides and phenolics.

Objective: To investigate the factors influencing the development of gastric cancer in Chinese populations, so as provide insights into creating a model for predicting gastric cancer incidence among Chinese populations. Methods: The case-control and cohort studies pertaining to factors affecting the development of gastric cancer were retrieved in electronic Chinese and English databases, including CNKI, Wanfang Data, VIP, PubMed, Web of Science and Embase from their inception until September 30, 2021. A meta-analysis was performed using R package version 4.1.0. Sensitivity analysis was performed using the “leave-one-out” evaluation procedure, and the publication bias was evaluated using the Egger regression test and the trim-and-fill procedure. Results: A total of 5 301 publications were screened and 116 eligible studies were included in the final analysis, including 103 case-control studies and 13 cohort studies, which covered approximately 3.23 million study subjects. A total of 45 factors affecting the development of gastric cancer were collected, and there were less than 4 publications reporting 7 factors, which were only qualitatively described. There were 38 factors included in the final meta-analysis. A total of 21 factors were identified as risk factors of gastric cancer, including a history of gastrointestinal diseases (pooled OR=4.85, 95%CI: 3.74-6.29), H. pylori infection (pooled OR=3.18, 95%CI: 2.35-4.32), binge eating and drinking (pooled OR=2.88, 95%CI: 2.09-3.97) and a family history of tumors (pooled OR=2.78, 95%CI: 2.17-3.56), and 10 factors as protective factors, including vegetable intake (pooled OR=0.48, 95%CI: 0.38-0.61), tea consumption (pooled OR=0.55, 95%CI: 0.47-0.64), administration of aspirin (pooled OR=0.53, 95%CI: 0.31-0.92) and administration of statins (pooled OR=0.59, 95%CI: 0.44-0.80). Sensitivity analyses of eating moldy food frequently, white meat intake, favoring spicy food and administration of sulfonylureas were not robust. Following correction with the trim-and-fill procedure, there was still a publication bias pertaining to high income, diabetes, administration of stains, alcohol consumption, tea consumption and white meat intake. Conclusions The development of gastric cancer is associated with a medical history of gastrointestinal disease, H. pylori infection, family history of tumors and poor dietary habits. Risk and protective factors of gastric cancer are recommended to be included in models used to predict gastric cancer incidence among Chinese populations.

Objective: To understand the awareness of sexual knowledge among primary and secondary school students, as well as their attitudes towards school sex education and to provide a reference for school-based sex education. Methods: A total of 5 531 primary and secondary school students were selected from Beijing, Chongqing, Heilongjiang (Harbin and Jiamusi) and Hubei (Wuhan and Xiaogan) by stratified cluster sampling and were investigated with self-reported questionnaire. Results: Sex-related knowledge scored 62.33±19.35, with a pass rate of 61.9%, and the excellent rate 17.5%. Sexual knowledge of junior high school students scored 64.30±19.07, with the pass rate of 64.7%, and the excellent rate 22.0%. A large proportion of primary students reported unaware of pubertal growth and HIV/AIDS-related knowledge, and a large proportion of junior high students unaware of reproductive physiology. Multivariate Logistic regression analysis showed region, grade, gender, and suburban areas were related to the level of sexual knowledge(P<0.05). More than 76.0% primary students and 85.9% middle school students agreed on the importance of school sexuality education. 59.7% of primary school students and 73.3% of junior high school students hoped to include school sexuality education in compulsory education courses; 59.8% of primary school students and 68.3% of junior high school students felt that school sexuality education should be equipped with specialized teachers. Conclusion Chinese primary and secondary school students are lack of sexual knowledge. As students have strong wills to get more information on sexual knowledge, schools should provide them with more comprehensive and effective sex education through appropriate courses and activities.

Epidemiology is one of main courses for undergraduate students majoring in preventive medicine.There are some limitations in the traditional epidemiology teaching,which is usually characterized in indoctrinated education:"lectured by the teachers and listened by the students." In Zhejiang University,staff of the epidemiology division tried to explore a new teaching mode as ‘student-centered,teacher-leading,question-based,and combining with literature discussion and course practice.'After practicing for two years,students were inspired in learning initiatives,with teaching effectiveness obviously improved.