Ding, Li Ping
Zhang, Fang Hui
Zhu, Yong Sheng
Lu, Cheng
Kuang, Xiao Yu
Lv, Jian
Shao, Peng
Article History
Received: 20 July 2015
Accepted: 2 October 2015
First Online: 3 November 2015
Competing interests
: The authors declare no competing financial interests.