Funding for this research was provided by:
China Medical Board (no. #15-224)
the National Social Science Found of China (no. 17BGL190)
Received: 4 December 2020
Accepted: 24 August 2021
First Online: 30 August 2021
: Written informed consent from each participant was obtained prior to data collection and sample collection. The study procedure was approved by the Human Studies Committee of Sun Yat-sen University in compliance with the Declaration of Helsinki—Ethical Principles for Medical Research Involving Human Subjects (no. IRB2014.9).
: Not applicable.
: The authors declare that they have no competing interests.