Wang, Jing
He, Linfeng
Fan, Dunhuang
Ding, Defang
Wang, Xufei
Gao, Yun
Zhang, Xuxia
Li, Qiang
Chen, Honghong
Article History
Received: 22 March 2016
Accepted: 27 June 2016
First Online: 22 July 2016
Competing interests
: The authors declare no competing financial interests.