OBJECTIVE:To understand the main diseases research area and tendency of the literatures published on top-five global biomedicine journals,and provide reference for topics and designs of domestic medical research. METHODS:Studies pub-lished on NEJM,JAMA,BMJ,Lancet and PLoS Medicine from 2004 to 2013 were searched via Web of Science;types of disease were classified by using International Classification of Diseases(version 10)(ICD-10);research types were analyzed according to the rules in clinical epidemiology. RESULTS:Most of studies(25.8%)were published on BMJ;USA(39.1%),UK(25.7%) and Canada(5.1%)were top-three countries for the first authors;circulation system disease,infectious and parasitic diseases,can-cer,endocrine,nutritional and metabolic disease and respiratory system disease were top-five in disease categories list,accounting for 61.7%;ischemic heart disease,HIV-related disease,diabetes,other heart disease and influenza and pneumonia were the main top-five specific diseases;and randomized controlled trials were main study type. CONCLUSIONS:The proportion of the first au-thor for the Chinese literature in the host country is very low. Top-five specific diseases are placed on circulation system disease,in-fectious and parasitic diseases,endocrine,nutritional and metabolic disease and respiratory system disease,with the main study types of randomized controlled trial,cohort study and systematic review.

Objective:To understand the positive rate of 2019 novel coronavirus (2019-nCoV) specific IgG antibody induced by Coronavirus Disease 2019 (COVID-19) inactivated vaccine in healthy population in Xizang Autonomous Region, and evaluate the immune effect of the vaccine.Methods:Serum samples were collected from COIVD-19 vaccine immunized health population without history of 2019-nCoV infection from six prefecture-level cities in Xizang Autonomous Region. The IgG antibody against 2019-nCoV were tested by chemiluminescence method. Then, the positive rate of IgG antibody was analyzed for different immunization histories and age groups.Results:A total of 22 255 participants were enrolled in this survey. After full-access (two doses of vaccine) and booster immunization, the overall positive rate of specific IgG antibody against 2019-nCoV was 96.38%. The positive rate of IgG antibody in the booster immunized population was 97.12%, which was much higher than the 88.38% in the full-access immunization population, the difference is statistically significant ( χ2=381.11, P<0.001). There was a significant differences in the positive rates of specific IgG antibodies in different age groups ( χ2=138.28, P<0.001). Especially in the younger age groups, including less than 10 years old and the 11-20 years age group, the positive rate of specific IgG antibody were 93.44% and 89.03% respectively, which were lower than those in other age groups. Except for Naqu city and the age group ≤ 10 years old, the differences in antibody positivity rates were statistically significant between different age groups in the same region and between the different regions in the same age group for the two populations with different immunization histories ( P<0.05). Conclusions:The COVID-19 inactivated vaccine showed a good immune effect in the healthy population in Xizang Autonomous Region, and the booster immunization helps to increase the positive rate of specific IgG antibody in healthy population.