Text and Data Mining valid from 2018-07-18
Received: 9 March 2018
Accepted: 27 June 2018
First Online: 18 July 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The present study was approved by the Research Ethics Committee of the Federal University of Rio Grande do Sul, Porto Alegre, Brazil (CAAE 51315215.7.0000.5342).All procedures performed in studies involving human participants were in accordance with the ethical standards of the Institutional Review Board and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.