Ueno, Akio
Shimizu, Satoru
Tamamura, Shuji
Okuyama, Hidetoshi
Naganuma, Takeshi
Kaneko, Katsuhiko
Article History
Received: 21 August 2015
Accepted: 2 December 2015
First Online: 8 January 2016
Competing interests
: The authors declare no competing financial interests.