Funding for this research was provided by:
National Natural Science Foundation of China (30770724)
Received: 4 July 2019
Accepted: 13 July 2020
First Online: 20 July 2020
Ethics approval and consent to participate
: The Institutional Ethics Committee of Dalian Medical University approved the study and waived the need for written informed consent from the participants, as the samples were remnants following clinical use and therefore not specifically collected for this study and without risk to patients.
: Not applicable.
: None declared.