Text and Data Mining valid from 2018-11-14
Received: 7 April 2018
Accepted: 2 November 2018
First Online: 14 November 2018
Compliance with ethical standards
: The authors declare no conflict of interest.
: All the procedures performed in the studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants involved in the study.