Quan, Kai
Liu, Qun
Wan, Jin-Yi
Zhao, Yi-Jing
Guo, Ru-Zhou
Alolga, Raphael N.
Li, Ping
Qi, Lian-Wen
Article History
Received: 28 October 2014
Accepted: 28 January 2015
First Online: 26 February 2015
Competing interests
: The authors declare no competing financial interests.