Wang, Min
Sun, Yuming
Sun, Guomei
Liu, Xiaokang
Zhai, Luchong
Shen, Qirong
Guo, Shiwei
Article History
Received: 26 August 2014
Accepted: 8 December 2014
First Online: 12 January 2015
Competing interests
: The authors declare no competing financial interests.