Text and Data Mining valid from 2018-11-05
Received: 29 August 2018
Accepted: 4 September 2018
First Online: 5 November 2018
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: For this type of study consent for publication is not required.
: 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 Declaration of Helsinki and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
: This study has obtained approval from our institutional review board, and the need for informed consent was waived.