Hirata, Naoya
Yamada, Shigeru
Shoda, Takuji
Kurihara, Masaaki
Sekino, Yuko
Kanda, Yasunari
Article History
Received: 28 December 2013
Accepted: 25 July 2014
First Online: 25 September 2014
Competing interests
: The authors declare no competing financial interests.