Otsuka, Takumi
Fujikawa, Shun-ichi
Yamane, Hideki
Kobayashi, Shiro
Article History
Received: 13 September 2016
Revised: 26 October 2016
Accepted: 31 October 2016
First Online: 21 December 2016
Competing interests
: The authors declare no conflict of interest.
Free to read: This content has been made available to all.