作者机构:[1]Department of Maternal and Child Health, School of Public Health, Peking University, Beijing 100191 China, [2]Institute of Child and Adolescent Health, Peking University, Beijing 100191, China, [3]Key Laboratory of Epidemiology, Ministry of Education, China,, [4]Dongcheng School Health Care Institute, Beijing 100005, China
相关基金:This research was supported by the grant from National Natural Science Foundation of China (30700668), Specialized Research Fund for the Doctoral Program of Higher Education (20070001811), and the Major State Basic Research and Development Program of China (973 program) (2006CB503900).
Correspondence should be addressed to Jun MA Institute ,of Child and Adolescent Health, Peking University, 38 Xueyuan Road,Beijing 100191, China. Tel: 86-10-82801624. Fax: 86-10-82801178. E-mail: majunt@bjmu.edu.cn