Funding for this research was provided by:
Agenzia Spaziale Italiana (2013–040–I.0)
Received: 19 October 2018
Accepted: 24 June 2019
First Online: 4 July 2019
Ethics approval and consent to participate
: This observational study was conducted in accordance with the ethical principles of the Declaration of Helsinki and was approved by the local institutional Ethics Committees (n. 5/2012 and 4/2013). All participants were enrolled after having signed an informed consent.
: Not applicable.
: The authors declare that they have no competing interests.