Du, P.
Hou, X.
Xie, Y.
Xu, S.
Li, L.
Zhang, J.
Wan, K.
Lou, Y.
Li, Z.
Funding for this research was provided by:
Ministry of Science and Technology of the People's Republic of China (2014AA021404)
National Health and Family Planning Commission of the People's Republic of China (CN) (2013ZX10004221)
National Health and Family Planning Commission of the People's Republic of China (CN) (2013ZX10004607)