Funding for this research was provided by:
Natural Science Foundation of Tongzhou District (KJ2019CX013)
Article History
Received: 4 January 2020
Accepted: 10 March 2020
First Online: 4 April 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: The study was in accordance with the guidelines of the Declaration of Helsinki, as revised in 2000, and approved by the ethics committee of Luhe Hospital.
: Informed consent was obtained from all participants.