Yuan, Hongjun
Li, Xin
Tian, Xiaomei
Ji, Kan
Liu, Fengyong
Funding for this research was provided by:
National Natural Science Foundation of China (81671800)
Natural Science Foundation of Beijing Municipality (7172204)
Article History
First Online: 27 February 2020
Compliance with ethical standards
:
: All authors declare that they have no conflict of interest.
: For retrospective studies, this type of study formal consent is not required.