Text and Data Mining valid from 2019-02-01
Received: 31 October 2018
Accepted: 25 January 2019
First Online: 1 February 2019
Compliance with ethical standards
: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
: 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.
: Informed consent was obtained from all individual participants included in the study.