Text and Data Mining valid from 2020-01-13
Received: 12 November 2019
Accepted: 5 January 2020
First Online: 13 January 2020
Compliance with ethical standards
: The authors declare that they have no conflicts of interest.
: All procedures performed were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards, and ethical approval was obtained from the Institutional Review Board of the University of Toyama.
: Informed consent was obtained from all individual participants included in the study.