Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (13GW0203A)
Text and Data Mining valid from 2020-01-10
Received: 25 July 2019
Accepted: 13 December 2019
First Online: 10 January 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in this study were approved by the local Ethical Committee of the University of Freiburg, Germany. This article does not contain any studies with animals performed by any of the authors.
: Subject retrospective data was handled with anonymity; therefore, no informed consent was obtained from all individual participants included in the study.