Huang, L
Wang, Z
Liu, C
Xu, C
Mbofung, R M
McKenzie, J A
Khong, H
Hwu, P
Peng, W
Article History
Received: 2 September 2016
Revised: 4 January 2017
Accepted: 5 January 2017
First Online: 6 March 2017
Competing interests
: The authors declare no conflict of interest.