Text and Data Mining valid from 2018-11-19
Received: 17 June 2018
Accepted: 18 October 2018
First Online: 19 November 2018
Compliance with ethical standards
: The authors have no sources of funding or conflicts of interest to declare.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional 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.