Tong, Qingjun
Yu, Hongyi
Zhu, Qizhong
Wang, Yong
Xu, Xiaodong http://orcid.org/0000-0003-0348-2095
Yao, Wang http://orcid.org/0000-0003-2883-4528
Article History
Received: 14 July 2016
Accepted: 27 October 2016
First Online: 28 November 2016
Competing interests
: The authors declare no competing financial interests.