Liu, S
Zhang, F
Shugart, Y Y
Yang, L
Li, X
Liu, Z
Sun, N
Yang, C
Guo, X
Shi, J
Wang, L
Cheng, L
Zhang, K
Yang, T
Xu, Y
Article History
Received: 15 August 2016
Revised: 22 October 2016
Accepted: 13 November 2016
First Online: 10 January 2017
Competing interests
: The authors declare no conflict of interest.