Fukui, H
Zhang, X
Sun, C
Hara, K
Kikuchi, S
Yamasaki, T
Kondo, T
Tomita, T
Oshima, T
Watari, J
Imura, J
Fujimori, T
Sasako, M
Miwa, H
Article History
Received: 10 February 2014
Revised: 17 May 2014
Accepted: 20 May 2014
First Online: 17 June 2014
Competing interests
: The authors declare no conflict of interest.