Received: 9 December 2020
Accepted: 19 April 2021
First Online: 14 May 2021
: The protocol of the study was approved by the Ethics Committee of The Third Affiliated Hospital of Guangzhou Medical University (GD2019–033). The participation was voluntary for each person involved in this study. Before launching the study, each volunteer signed an informed consent which contained the following information: (1) aims and tasks of the study; (2) protocol of the study; (3) criteria for inclusion in the study; (4) duties of a volunteer participating in the study; (5) benefits for taking part in the study; (6) potential risks, inconvenience, and adverse effects. The volunteers could refuse participation in the study at any stage without any consequences.
: Not applicable.
: The authors declare that they have no competing interests.