Yu, T
Chen, X
Zhang, W
Liu, J
Avdiushko, R
Napier, D L
Liu, A X
Neltner, J M
Wang, C
Cohen, D
Liu, C
Article History
Received: 16 February 2015
Revised: 29 April 2015
Accepted: 22 May 2015
First Online: 26 June 2015
Competing interests
: The authors declare no conflict of interest.