Text and Data Mining valid from 2019-09-04
Received: 17 March 2019
Accepted: 30 August 2019
First Online: 4 September 2019
Ethics approval and consent to participate
: The Ethical Committee of Jichi Medical University approved this study. This study obtained exempted approval from the institutional review board based on our guideline (approval #Rin-Dai 17–147). The institutional review board waived the requirement for participants or patients to give consent.
: Not applicable.
: The authors declare that they have no competing interests.