Kawasaki, Seiji
Takahashi, Ryota
Yamamoto, Takahisa
Kobayashi, Masaki
Kumigashira, Hiroshi
Yoshinobu, Jun
Komori, Fumio
Kudo, Akihiko
Lippmaa, Mikk
Article History
Received: 29 November 2015
Accepted: 3 May 2016
First Online: 3 June 2016
Competing interests
: The authors declare no competing financial interests.