Nagaoka, K
Fujii, K
Zhang, H
Usuda, K
Watanabe, G
Ivshina, M
Richter, J D
Article History
Received: 10 February 2015
Revised: 28 July 2015
Accepted: 17 August 2015
First Online: 28 September 2015
Competing interests
: The authors declare no conflict of interest.