Funding for this research was provided by:
BMWi (KF 2026723AK4)
Article History
Received: 17 May 2018
Accepted: 28 November 2018
First Online: 5 December 2018
Compliance with ethical standards
:
: The authors declare no conflict of interest.
: 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 Declaration of Helsinki and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.