Text and Data Mining valid from 2018-06-25
Received: 8 March 2018
Accepted: 12 June 2018
First Online: 25 June 2018
Compliance with ethical standards
: We declare that no conflicts of interest exist. No financial gain is obtained from this study and its findings.
: All procedures performed in studies involving human participants were carried out in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 (and subsequent) Helsinki declaration(s) and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in this study.