Nagai, Jun
Kitamura, Yoshiteru
Owada, Kazuki
Yamashita, Naoya
Takei, Kohtaro
Goshima, Yoshio
Ohshima, Toshio
Article History
Received: 11 September 2014
Accepted: 14 January 2015
First Online: 5 February 2015
Competing interests
: The authors declare no competing financial interests.