Ethics approval and consent to participate
This study was approved by the Ethics Committee of the Guangdong Provincial Hospital of Chinese Medicine (Approval No. B2016-202-01). All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with those of the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants involved in the study. All procedures in this study were carried out in accordance with relevant guidelines and regulations.