Zhang, Haicheng
Liu, Shuguang
Yuan, Wenping
Dong, Wenjie
Ye, Aizhong
Xie, Xianhong
Chen, Yang
Liu, Dan
Cai, Wenwen
Mao, Yuna
Article History
Received: 28 July 2014
Accepted: 12 November 2014
First Online: 28 November 2014
Competing interests
: The authors declare no competing financial interests.