Funding for this research was provided by:
Grants from the Japan Society for the Promotion of Science KAKENHI (26860372, 25870541, 24249036)
Received: 27 December 2018
Accepted: 19 May 2019
First Online: 27 May 2019
Ethics approval and consent to participate
: The Human Ethics Review Committee of Kumamoto University approved the study protocol. Subjects or families of subjects provided signed consent forms.
: Not applicable.
: The authors declare that they have no competing interests.