Ma, Ning
Cheng, Huaibing
Lu, Minjie
Liu, Qiong
Chen, Xiuyu
Yin, Gang
Zhu, Hao
Zhang, Lianfeng
Meng, Xianmin
Tang, Yue
Zhao, Shihua
Article History
Received: 25 June 2014
Accepted: 5 February 2015
First Online: 12 March 2015
Competing interests
: The authors declare no competing financial interests.