Text and Data Mining valid from 2018-07-03
Received: 6 April 2018
Accepted: 29 May 2018
First Online: 3 July 2018
Ethics approval and consent to participate
: 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.
: The authors of this manuscript declare no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.