Article History
Received: 7 August 2018
Accepted: 4 October 2018
First Online: 20 October 2018
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study has been examined and approved by the Institutional Ethics Committee of Shanghai Chest.
: Informed consent was obtained from all individual participants included in the study.