Funding for this research was provided by:
Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México (IN221219, IN224617)
Received: 4 March 2020
Accepted: 18 June 2020
First Online: 28 July 2020
Ethics approval and consent to participate
: This study was approved by Ethical Committees of INCan (019/060/OMI) and UNAM (FM/DI/108/2015).
: Not Applicable.
: The authors declare no competing interest.