Text and Data Mining valid from 2019-05-10
Received: 9 January 2019
Accepted: 19 April 2019
First Online: 10 May 2019
Compliance with Ethical Standards
: On behalf of all authors, the corresponding author states that there is 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, and this study has obtained IRB approval.