Funding for this research was provided by:
Clinical medicine +X Project of Affiliated Hospital of Qingdao University (QDFY+X2021016)
Article History
Received: 8 March 2021
Accepted: 5 May 2021
First Online: 10 May 2021
Declarations
:
: The Ethics Committee of The Affiliated Hospital of Qingdao University approved the study. Informed consent was obtained from all these patients or their guardians.
: The written consent is available for review by the chief editor.
: The authors declare that they have no competing interests.