Funding for this research was provided by:
Natural Science Foundation of Shandong Province (ZR2017BH095, ZR2017BH072, ZR2014P065)
National Natural Science Foundation of China (81702362, 81802379, 81803026)
Jinan Science and Technology Bureau (201805029)
Text and Data Mining valid from 2019-11-04
Received: 18 August 2019
Accepted: 16 October 2019
First Online: 4 November 2019
Ethics approval and consent to participate
: The study protocol was performed following the Declaration of Helsinki. Samples were collected after approval by the Medical Ethics Committee of Shandong Provincial Hospital affiliated to Shandong University and written informed consents were obtained from each patient.
: All authors have seen and approved the manuscript and consent for publication.
: The authors declare that they have no competing interests.