Cong, Xiaowei
Article History
Received: 26 November 2017
Accepted: 13 February 2018
First Online: 27 February 2018
Compliance with ethical standards
: This study was approved by the Human Ethics Committee of Shantou University Medical College, China, and limited to analysis of existing data that involved no direct inter action with subjects and therefore met criteria for a waiver of informed consent (Smith et al. CitationRef removed).
: The author declares that he has no conflict of interest.