Received: 20 November 2018
Accepted: 5 September 2019
First Online: 14 September 2019
Ethics approval and consent to participate
: The study was approved by the Ethical Board Review of the Beilun People’s Hospital (Ningbo, Zhejiang, China), participant consent was written, and the reference number was ChiCTR1800019089 and was performed in accordance with the ethical standards of the Declaration of Helsinki of 1964.
: Not applicable
: The authors declare that they have no competing interests.