Funding for this research was provided by:
China Association for Science and Technology (castqk2017-qnkt-01)
Received: 27 November 2018
Accepted: 27 November 2019
First Online: 5 December 2019
Ethics approval and consent to participate
: The study is exempt from review by the Ethics Committee of Nanfang Hospital based on the basis that this type of study is non-human subject research, and waived the need for informed consent.
: Not applicable.
: The authors declare that they have no competing interests.