Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (01EC1404A)
Received: 13 November 2017
Accepted: 9 April 2019
First Online: 30 April 2019
Ethics approval and consent to participate
: This study has been approved by the Ethical Review Committees of the Faculties of Medicine in Tuebingen (Project number 150/2015BO1) and Heidelberg (Project number S-256/2015).In accordance with the ethical standards and the Declaration of Helsinki, written informed consent to participate in the study is obtained from all participants (or legal guardian).
: Not applicable.
: The authors declare that they have no competing interests.
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