Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (14207020, 17209024)
Received: 19 August 2019
Accepted: 10 February 2020
First Online: 17 February 2020
Ethics approval and consent to participate
: This study protocol was approved by the Medical Ethics Committee of Showa University School of Medicine (Approval No. 127). Written informed consent was obtained from the parent or guardian of each subject prior to the subject’s participation in this study.
: Not applicable.