Morgenthal, S.
Bayer, R.
Doerre, A.
Dreßler, J.
Article History
Received: 4 May 2015
Accepted: 9 September 2015
First Online: 19 September 2015
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: All procedures performed were carried out in accordance with the Helsinki Declaration of 1964 (in its current, revised form from 2013).
: Informed consent was obtained from all individual participants included in the study.