Open Access
Volume 9, Number 4, December 2019
Article Number 27
Number of page(s) 7
Published online 14 November 2019

© Author(s) 2019. This article is published with open access by China Medical University

Licence Creative CommonsOpen Access This article is distributed under terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided original author(s) and source are credited.