Funding for this research was provided by:
grant-in-aid for scientific research on innovative areas (No. 21119002)
Received: 17 March 2020
Accepted: 30 September 2020
First Online: 7 October 2020
Ethics approval and consent to participate
: The ethics committee of the Graduate School of Medicine and Faculty of Medicine, The University of Tokyo approved this study [No.3073, approved 27/6/2010, last update 11/7/2017]. Consent for participation in the study and the agreement for publication was indicated by completing and returning the self-administered questionnaire.
: Not Applicable.
: The authors declare that they have no competing interests.