Text and Data Mining valid from 2018-05-02
Received: 27 October 2017
Accepted: 24 April 2018
First Online: 2 May 2018
Ethics approval and consent to participate
: This study was approved by the Research Ethics Committee of the Federal University of Rio Grande do Norte under protocol number 31747714.7.0000.5568. The study was conducted in accordance with the requirements of the declarations of Helsinki. All participants were informed about the procedures and signed an informed consent form prior to enrollment in the study.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.