Published on in Vol 7, No 9 (2019): September
1 Department of Social Medicine and Health Education, School of Public Health, Peking University, Beijing, China
2 Institute of Reproductive and Child Health, School of Public Health, Peking University, Beijing, China
3 Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, China
4 School of Journalism and Communication, Peking University, Beijing, China
5 Global health center office of Beijing Research Center for preventive medicine, Beijing Center for Disease Control and prevention, Beijing Center for Disease Control and prevention, Beijing, China
*these authors contributed equally