Funding for this research was provided by:
the Beijing Medical and Health Foundation , China (YWJKQ4008)
Article History
First Online: 15 October 2019
Compliance with ethics guidelines
: Ge-han XU, Hua-wei ZOU, and Ashley B. GROSSMAN declare that they have no conflict of interest.
: This article does not contain any studies with human or animal subjects performed by any of the authors.