Li, Pan
Liu, Haowen
Lai, Chaohua
Sun, Peibei
Zeng, Wenping
Wu, Fangming
Zhang, Longhua
Wang, Sheng
Tian, Changlin
Ding, Jiuping
Article History
Received: 23 December 2013
Accepted: 17 April 2014
First Online: 15 May 2014
Competing interests
: The authors declare no competing financial interests.