Text and Data Mining valid from 2020-02-28
Received: 8 December 2019
Accepted: 19 February 2020
First Online: 28 February 2020
Ethics approval and consent to participate
: The study was approved by the ethics committee of the Ruhr-University Bochum (No. 4929–14). All experimental work was conducted in accordance with the Declaration of Helsinki. Subjects gave written informed consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.