Text and Data Mining valid from 2018-11-15
Received: 20 June 2018
Accepted: 6 November 2018
First Online: 15 November 2018
Compliance with ethical standards
: The 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 and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.For this type of study, formal consent is not required.
: Informed consent was obtained from all individual participants for whom identifying information is included in this article.