Text and Data Mining valid from 2019-04-26
Received: 11 November 2018
Accepted: 24 December 2018
First Online: 26 April 2019
Compliance with ethical standard
: All authors declare that they have no conflict of interest.
: This study was approved by the local ethic committee. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all participants included in the study.