Funding for this research was provided by:
Major Research Plan (No. 8167102678)
special project of social undertakings and social security innovation in Chongqing (81502241)
Text and Data Mining valid from 2019-08-09
Received: 19 March 2019
Accepted: 26 June 2019
First Online: 9 August 2019
Compliance with ethical standards
: Luo Hao, Zhang Liang, Yang Bo, Feng Yan, Xiong Yanli, Zhang Shiheng, Li Xuemei, Qian Chengyuan, Dong Wang and Dai Nan declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethics committee of Daping Hospital & Army Medical Center of PLA and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.