Duan, Yongliang
Liu, Lin
Han, Guoqing
Liu, Hongwei
Yu, Weidong
Yang, Guang
Wang, Huiwu
Wang, Haiyuan
Liu, Yanliang
Zahid,
Waheed, Hussain
Article History
Received: 16 November 2015
Accepted: 23 June 2016
First Online: 20 July 2016
Competing interests
: The authors declare no competing financial interests.