Chen, Weiguo
Liu, Yang
Li, Hongxing
Chang, Shuang
Shu, Dingming
Zhang, Huanmin
Chen, Feng
Xie, Qingmei
Article History
Received: 19 November 2014
Accepted: 17 March 2015
First Online: 15 April 2015
Competing interests
: The authors declare no competing financial interests.