Funding for this research was provided by:
Tianjin Municipal Bureau of Public Health (16KG158)
Foundation of Tianjin Union Medical Center (2017YJ024, 2018YJ010)
Received: 30 June 2019
Accepted: 12 September 2019
First Online: 22 October 2019
Ethics approval and consent to participate
: This article does not contain any studies with animals. Written informed consent was obtained from all individual participants included in the study according to the rules of the Institutional Review Committee of Tianjin Union Medical Center. All procedures performed in our study were in accordance with the ethical standards of the Institutional Review Committee of Tianjin Union Medical Center and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The manuscript submitted contains no information about medical device(s)/drug(s). No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. The authors declare that they have no competing interests.