Yao, Bo
Liu, Wen-juan
Liu, Di
Xing, Jin-yan
Zhang, Li-juan
Funding for this research was provided by:
China Postdoctoral Science Foundation (2019M662306)
Postdoctoral Applied Research Programs Foundation of Qingdao city of China (201918)
Article History
Received: 28 May 2020
Accepted: 26 October 2020
First Online: 3 November 2020
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the affiliated hospital of Qingdao University (No. QYFY WZLL 25945) and therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The written informed consent is not needed because this study is a retrospective study.
: Not applicable.
: The authors declare that they have no competing interests.