Text and Data Mining valid from 2019-01-22
First Online: 22 January 2019
Compliance with Ethical Standards
: None of the authors have any financial disclosure/conflict of interest related to this manuscript.
: 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: Informed consent was obtained from all individual participants included in the study.