Funding for this research was provided by:
Technische Universität München
Received: 14 April 2020
Accepted: 22 May 2020
First Online: 6 June 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article reviews studies involving human participants. To the best of our knowledge, the included studies were in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: As no human participants were included in our study, the need for informed consent was not applicable.