Text and Data Mining valid from 2019-07-13
Received: 4 April 2019
Revised: 19 June 2019
Accepted: 5 July 2019
First Online: 13 July 2019
Compliance with ethical standards
: The study was approved by the local ethical Committee of the University Federico II, Naples, Italy (number approval 5/12), and was conducted in conformity with The Declaration of Helsinki and its later amendments. A written informed consent was obtained from all participants.