Li, Yongfeng
Ma, Hua
Wang, Jiafu
Pang, Yongqiang
Zheng, Qiqi
Chen, Hongya
Han, Yajuan
Zhang, Jieqiu
Qu, Shaobo
Article History
Received: 18 October 2016
Accepted: 9 December 2016
First Online: 12 January 2017
Competing interests
: The authors declare no competing financial interests.