Text and Data Mining valid from 2018-10-10
Received: 10 July 2018
Accepted: 26 September 2018
First Online: 10 October 2018
Compliance with Ethical Standards
: All authors disclose no conflict of interest with respect to the research, authorship, and 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.