Nagashima, Yukiko
Shigeishi, Hideo
Fukada, Eri
Amano, Hideaki
Urade, Masahiro
Sugiyama, Masaru
Article History
Received: 3 March 2018
Accepted: 12 July 2018
First Online: 10 September 2018
Ethics approval and consent to participate
: The study design was approved by the Ethical Committee of Hiroshima University (No. 1814) and informed consent was obtained from all participants and individuals in parental authority.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.