Funding for this research was provided by:
Key Laboratory of Highway Construction and Maintenance Technology in the Loess Region of Shanxi Transportation Research Institute (2016zdyf01)
the Projects of Lishui Key Research and Development Plan in Zhejiang Province, China (2017ZDYF12)
Received: 11 December 2020
Accepted: 28 March 2021
First Online: 1 April 2021
: The study was approved by the Ethics Committee of Lishui Municipal Central Hospital (Approval number: 2020-249). Need for written informed consent was waived owing to the retrospective nature of the study.
: Not applicable as there is no identifiable material in this manuscript.
: The authors declare that they have no competing interests.