Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (17K09070)
Text and Data Mining valid from 2019-11-26
Received: 23 June 2019
Accepted: 19 November 2019
First Online: 26 November 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: This article does not contain patient data.