Text and Data Mining valid from 2018-12-19
Received: 13 November 2018
Revised: 9 December 2018
Accepted: 12 December 2018
First Online: 19 December 2018
Compliance with Ethical Standards
: The authors declare no conflicts 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.