Text and Data Mining valid from 2017-07-01
Received: 11 February 2017
Accepted: 22 June 2017
First Online: 1 July 2017
Compliance with Ethical Standards
: The authors declare 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.