Liu, Xiaoyuan
Xiang, Wensheng
Jiao, Xiaoguo
Zhang, Youjun
Xie, Wen
Wu, Qingjun
Zhou, Xuguo
Wang, Shaoli
Article History
Received: 8 January 2014
Accepted: 13 June 2014
First Online: 6 August 2014
Competing interests
: The authors declare no competing financial interests.