Document is current

Article History

Received: 27 February 2017

Accepted: 7 February 2018

First Online: 20 February 2018

Ethics approval and consent to participate

: All participants gave written informed consent for study participation. The study was conducted in accordance with the Declaration of Helsinki. The study protocol was approved by the Ethics Committee (No 3278–10/11) of the Friedrich-Schiller-University, Jena, Germany.

: Not applicable.

: The authors declare that they have no competing interests.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.