Article History
Received: 26 December 2018
Revised: 24 April 2019
Accepted: 20 May 2019
First Online: 4 July 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in this study were in accordance with the ethical standards of the Beijing Tongren Hospital research committee and with the 1964 Helsinki declaration and its later amendments.
: Informed consent was obtained from all individual participants in the study.