Yan, H
Solozobova, V
Zhang, P
Armant, O
Kuehl, B
Brenner-Weiss, G
Blattner, C
Article History
Received: 5 August 2014
Revised: 15 December 2014
Accepted: 15 January 2015
First Online: 26 February 2015
Competing interests
: The authors declare no conflict of interest.