Zhang, Lei
Wu, Tian-Ge
He, Yu-Jie
Guo, Jin-Yan
Han, Li-Shuai
Lu, Jia-Meng
Liu, Sheng-Yun
Li, Tian-Fang
Article History
Received: 31 May 2019
Revised: 31 October 2019
Accepted: 11 November 2019
First Online: 8 February 2020
Compliance with ethical standards
:
: None.
: This retrospective study was approved by the Ethic Committee of Zhengzhou University (SR-2018-LW-050) and was conducted in accordance with the Declaration of Helsinki. When analyzing the data, personal information such as name, hospital number, etc. were replaced by index numbers.