Text and Data Mining valid from 2018-08-01
Received: 21 March 2018
Accepted: 8 June 2018
First Online: 1 August 2018
Ethics approval and consent to participate
: The protocol of this study was carried out according to the principles of the Declaration of Helsinki and approved by the Medical Ethics Committee of First Affiliated Hospital of Soochow University. As this article is a retrospective study, ethics committees have been granted exemption of patient informed consent.
: No applicable.
: The authors declare that they have no competing interests.