Text and Data Mining valid from 2020-03-20
Received: 9 May 2019
Accepted: 23 January 2020
First Online: 20 March 2020
Ethics approval and consent to participate
: The study protocol was approved by the institutional review board of Hiroshima International University (12-025), and informed consent was obtained from all subjects included in the study prior to the initiation of this study.
: Not applicable.
: The authors declare that they have no competing interests.