Horiuchi, Sachio
Kobayashi, Kensuke
Kumai, Reiji
Minami, Nao
Kagawa, Fumitaka
Tokura, Yoshinori
Article History
Received: 13 January 2015
Accepted: 12 May 2015
First Online: 16 June 2015
Competing interests
: The authors declare no competing financial interests.