1. Department of Ultrasound Affiliated Hospital of North Sichuan Medical College Nanchong 637000 China
2. College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 China
3. Department of Chemistry Lorestan University Khorramabad 68137‐17133 Iran
4. Institute of Chemistry and Biochemistry Freie Universitat Berlin Takustr. 3 14195 Berlin Germany
5. Department of Medical Ultrasound West China Hospital Sichuan University Chengdu 610041 China
6. State Key Laboratory of Oral Diseases National Clinical Research Center for Oral Diseases West China Hospital of Stomatology Sichuan University Chengdu 610041 China