Funding for this research was provided by:
Henan Province Science and Technology Tackling Project (172102310116)
Text and Data Mining valid from 2020-03-07
Received: 11 November 2019
Accepted: 26 February 2020
First Online: 7 March 2020
Ethics approval and consent to participate
: This study was performed in accordance with institutional ethical guidelines and was approved by the Ethics Committee of Henan Provincial Chest Hospital. Informed written consent was obtained from each participants.
: All authors approved publication of the manuscript.
: The authors report no conflicts of interest in this work.