Funding for this research was provided by:
National Natural Science Foundation of China (81272981)
the Beijing Natural Science Foundation (7151003)
nd the Advanced Health Care Professionals Development Project of Beijing Municipal Health Bureau (2014-2-003)
Text and Data Mining valid from 2019-04-29
Received: 13 December 2018
Revised: 3 April 2019
Accepted: 5 April 2019
First Online: 29 April 2019
Compliance with ethical standards
: All authors declare that they have no conflicts of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Following the tenets of the Declaration of Helsinki, the research protocol was approved by the Medical Ethics Committee of the Beijing Tongren Hospital.
: Informed consent was obtained from all individual participants included in the study.