Funding for this research was provided by:
the Grant-in-Aid for Young Scientists (20K18847)
Received: 11 June 2020
Accepted: 8 December 2020
First Online: 4 January 2021
Ethics approval and consent to participate
: The study did not require ethical approval because the study was a review of the published articles and websites.
: Not applicable.
: There are no potential competing interests to be declared relevant to this work.