Funding for this research was provided by:
National Natural Science Foundation of China (81472729, 81672426)
Article History
Received: 26 April 2018
Accepted: 22 June 2018
First Online: 28 June 2018
Compliance with ethical standards
:
: The authors declare no conflict of interest.
: This study has been approved by Tianjin Union Medical Center’s ethics committee and has been performed according to the ethical standards laid down in the 1964 Declaration of Helsinki.
: Informed consent was obtained from all individual participants included in the study.