Funding for this research was provided by:
Young Scientists Fund (81801990)
Text and Data Mining valid from 2019-08-05
Received: 6 September 2018
Accepted: 17 June 2019
First Online: 5 August 2019
Ethics approval and consent to participate
: The protocol was established according to the ethical guidelines of the Helsinki Declaration and approved by the Human Ethics Committee of Department of Respiratory Disease, The Seventh People’s hospital of Chongqing. Written informed consent was obtained from individual participants.
: Not applicable.
: The authors declare that they have no competing interests.