Received: 23 February 2021
Accepted: 24 May 2021
First Online: 7 June 2021
: The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Review Board (or Ethics Committee) of the University of Palermo (Comitato Etico Palermo 1, N. 04, 2018).
: Informed consent was obtained from all subjects involved in the study.
: The authors declare no conflict of interest.