Ohira, Suguru
Tanaka, Hideo
Harada, Yoshinori
Minamikawa, Takeo
Kumamoto, Yasuaki
Matoba, Satoaki
Yaku, Hitoshi
Takamatsu, Tetsuro
Article History
Received: 25 July 2016
Accepted: 9 January 2017
First Online: 10 February 2017
Competing interests
: The authors declare no competing financial interests.