. 2018 Dec 18;2018:8923520. doi: 10.1155/2018/8923520
Copyright © 2018 Xiuyuan Zheng et al.
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 1.
Flowchart of the study.