Text and Data Mining valid from 2018-07-11
Received: 9 May 2017
Accepted: 26 June 2018
First Online: 11 July 2018
Compliance with Ethical Standards
: All authors declares that they have no conflict of interest.
: 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.