Text and Data Mining valid from 2018-02-21
Received: 13 December 2017
Accepted: 16 February 2018
First Online: 21 February 2018
Compliance with ethical standards
: The authors did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors, and report no conflicts of interest in this work.
: This study was conducted in accordance with the International Conference on Harmonisation-Good Clinical Practice and the Declaration of Helsinki (2008), and was approved by the institutional research ethics committee of Shinshu University School of Medicine (No. 2099).
: All subjects were given an adequate explanation of the study and provided written informed consent.