Text and Data Mining valid from 2018-04-12
Received: 19 December 2017
Accepted: 7 April 2018
First Online: 12 April 2018
Compliance with Ethical Standards
: The authors declare that they have no conflicts of interest.
: Institutional. All procedures performed in studies involving human participants were in accordance with ethical standards of the institution committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individuals.