Text and Data Mining valid from 2018-02-16
Received: 4 December 2017
Accepted: 1 February 2018
First Online: 16 February 2018
Compliance with ethical standards
: On behalf of all authors, the corresponding author states that there are no relationships that could be construed as a conflict of interest.
: All procedures performed in study involving human participants were approved by the local institution’s ethics committee.