About the Authors
- Li Liu, Mengying Li, Neff Walker, Jennifer Bryce, Robert E. Black
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Li Yang
- Guangxi Medical University, School of Public Health, Nanning, China
- Lirong Ju
- Capital Medical University, School of Public Health, Beijing, China
- Biqin Tan
- Gongcheng County Maternal and Child Health Hospital, Gongcheng County, China
- Harry Campbell
- University of Edinburgh Medical School, Edinburgh, United Kingdom
- Yan Guo
- Peking University Health Science Center, School of Public Health, Beijing, China
The authors have declared that no competing interests exist.
Interpretation of results and subsequent revision of the manuscript: LL ML LY LJ BT NW JB HC REB YG. Conceived and designed the experiments: LL NW JB HC RB YG ML. Performed the experiments: LL ML LJ LY BT YG. Analyzed the data: ML LL. Wrote the paper: LL ML.