Funding for this research was provided by:
damascus university (1938)
Received: 23 March 2020
Accepted: 18 June 2020
First Online: 10 August 2020
Ethics approval and consent to participate
: This study has been approved by the ethical committee of Damascus University-Syria (no.1052/ 2018). A written informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.