Xu, Chenggang
Huang, Ranran
Teng, Lin
Jing, Xiaoyan
Hu, Jianqiang
Cui, Guzhen
Wang, Yilin
Cui, Qiu
Xu, Jian
Article History
Received: 5 August 2014
Accepted: 11 March 2015
First Online: 24 April 2015
Competing interests
: The authors declare no competing financial interests.