Pang, Xiaojing
Xiao, Xiaoping
Liu, Yang
Zhang, Rudian http://orcid.org/0000-0003-2214-4892
Liu, Jianying
Liu, Qiyong
Wang, Penghua
Cheng, Gong
Article History
Received: 16 October 2015
Accepted: 1 February 2016
First Online: 14 March 2016
Competing interests
: The authors declare no competing financial interests.