Zhang, Yanting
Dong, Siqin
Fang, Wenjie
Chai, Xiaohui
Mei, Jiaojiao
Fan, Xiuzhen
Funding for this research was provided by:
the Natural Science Foundation of Shandong Province (No. ZR2013CM039)
the comprehensive education and teaching reform program of Shandong University 2015
Article History
Received: 22 August 2017
Accepted: 11 May 2018
First Online: 29 May 2018
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: The Medical Ethics Committee of Shandong University approved the study.