Funding for this research was provided by:
National Key Technologies R&D Program (2015BAI13B09)
Received: 25 March 2018
Accepted: 10 June 2019
First Online: 8 July 2019
Ethics approval and consent to participate
: This study was approved by Ethic Committee of Beijing Friendship Hospital, and this Ethic Committee comply with the Declaration of Helsinki (Approval No. 2016-P2–107-01).This is a retrospective study. The ethics committee agreed to exempt the informed consent. According to the China Health Committee issued “Ethical Review of Biomedical Research involving Human Beings” (2016), thirty-ninth: on the identity information of human material or data, has been unable to find the subjects, and the research project is not related to personal privacy and commercial interests, can be exempt from informed consent.
: Not applicable. Our manuscript does not contains any individual person’s data in any form (including individual details, images or videos).
: The authors declare that they have no competing interests.