Authors’ contributions
All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published. Changgui Li and Mingshu Sun were responsible for study conception and design; Can Wang and Wenyan Sun were responsible for data analysis and manuscript preparation; Zhongjun Wang, Xuefeng Wang, Xiaopeng Ji, Lin Han, Lingling Cui, Xinde Li, Zhen Liu, Aichang Ji, and Yuwei He all participated in data and sample acquisition; Nicola Dalbeth and Xiaomei Xue participated in data interpretation and manuscript revision.