Ethics approval and consent to participate
This trial was registered in ClinicalTrials.gov on 21/04/2014 (NCT02117557). The Ethics Committee of Southern Medical University approved the trial (Reference number: NFEC-2014-026). Written informed consent was obtained from all patients before they were enrolled in this study. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013) and methods were carried out in accordance with relevant guidelines and regulations.