Wang, Xuezhen
Zhang, Lecheng
Yu, Yi-Hsien
Jia, Lisi
Sam Mannan, M.
Chen, Ying
Cheng, Zhengdong
Article History
Received: 7 April 2015
Accepted: 23 July 2015
First Online: 17 August 2015
Competing interests
: The authors declare no competing financial interests.