Guo, Chenyi
Yang, Xianwei
Wu, Yarong
Yang, Huiying
Han, Yanping
Yang, Ruifu
Hu, Liangping
Cui, Yujun
Zhou, Dongsheng
Article History
Received: 17 July 2014
Accepted: 3 December 2014
First Online: 5 January 2015
Competing interests
: The authors declare no competing financial interests.