Article History
Received: 11 June 2020
Accepted: 14 September 2020
First Online: 2 October 2020
Ethics approval and consent to participate
: I confirm that I have read the Editorial Policy pages. This study was conducted with approval from the Ethics Committee of the Fourth Hospital of Hebei Medical University. This study was conducted in accordance with the declaration of Helsinki. Consent is not applicable as there were no human participants.
: Not applicable.
: All the authors declare that they have no competing interest.