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Article History

Received: 17 January 2018

Accepted: 15 May 2018

First Online: 29 May 2018

Ethics approval and consent to participate

: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was endorsed by the Leipzig Ethics Committee (file: 030–14-27012014).

: Informed consent was obtained from all individual participants included in the study.

: The authors declare that they have no competing interests.

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