Funding for this research was provided by:
Japan Society for the Promotion of Science (18K07660)
Received: 30 April 2021
Accepted: 5 November 2021
First Online: 15 November 2021
: Hiroyuki Katoh received research funding from Toshiba Energy Systems & Solutions Corporation. The other authors declare that they have no conflict of interest to report.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: The research protocols were approved by the institution review boards of each institution, which granted a waiver of informed consent from study participants due to the retrospective nature of the study.