Text and Data Mining valid from 2019-05-15
Received: 21 December 2018
Accepted: 13 May 2019
First Online: 15 May 2019
Compliance with Ethical Standards
: All authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional ethics committee (EC/329/17/03) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants enrolled in the study.