Funding for this research was provided by:
Japan Agency for Medical Research and Development (JP19fk0108061)
Received: 10 December 2019
Accepted: 18 February 2020
First Online: 4 March 2020
Ethics approval and consent to participate
: This study has been approved by the ethical committee of Hiroshima University Hospital review board (E-1704).
: Not applicable.
: The authors declare that they have no competing interests.