Author contributions
Weibin Liu, Lin Ma, and Huaxiu Cai are co-first authors. Jun Cao and Gang Cao are co-corresponding authors. This study was designed by Weibin Liu, Jun Cao, Fang Pei, Gang Cao. Data entry and verification by Yin Zheng and Yongkang Wen; Ultrasonic measurement was performed by Lin Ma. Statistical analysis was conducted by Huaxiu Cai.