Text and Data Mining valid from 2019-07-19
Received: 21 December 2018
Accepted: 5 July 2019
First Online: 19 July 2019
Ethics approval and consent to participate
: No patient-related data was used in our work, therefore there is no need for approval by an ethics committee.
: All authors gave consent for submission and publication.
: The authors declare that they have no competing interests.