International Acupuncture and Moxibustion Innovation Institute, School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine

Conflict of interest statement: The author declares no conflict of interest.

Funding: None.

Author Contributions: Cunzhi Liu drafted and approved the manuscript.

Ethical approval of studies and informed consent: Not applicable.

Acknowledgements: None.

Data Availability: Not applicable.

^*Correspondence: Cun-Zhi Liu, International Acupuncture and Moxibustion Innovation Institute, School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, No. 11 Bei San Huan Dong Lu, Chaoyang District, Beijing 100029, China. Email: [email protected].

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