Wang, Hua
Fang, Yan
Wang, Lipeng
Zhu, Wenjuan
Ji, Haipeng
Wang, Haiying
Xu, Shiqing
Sima, Yanghu
Article History
Received: 29 October 2014
Accepted: 2 February 2015
First Online: 4 March 2015
Competing interests
: The authors declare no competing financial interests.