Text and Data Mining valid from 2018-01-29
Received: 6 September 2017
Accepted: 17 January 2018
First Online: 29 January 2018
Compliance with ethical standards
: 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.