Submitted on: 20 March 2001.
Revised on: 02 April 2001.
Accepted on: 24 April 2001.
Minerva Respiratory Medicine
http://reply.papertrans.cn/3/221/22060/22060-32.png
http://reply.papertrans.cn/3/221/22060/22060-33.png
Submitted on: 13 March 2016.
Revised on: 21 March 2016.
Accepted on: 14 April 2016.
Minerva Respiratory Medicine
http://reply.papertrans.cn/3/221/22060/22060-35.png
http://reply.papertrans.cn/3/221/22060/22060-36.png