1. Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States
2. Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409, United States
3. School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P. R. China
4. Department of Chemistry & Biochemistry and the Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States