Zhang, Yonggang
Jia, Airong
Chen, Huabin
Wang, Menghua
Ding, Gang
Sun, Liyan
Li, Li
Dai, Meixue
Article History
Received: 14 June 2017
Revised: 30 August 2017
Accepted: 4 September 2017
First Online: 11 October 2017
Competing interests
: The authors declare no conflict of interest.
Free to read: This content has been made available to all.