1. Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
2. Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
3. School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
4. Department of Mathematics and Statistics, Texas Tech University, 1108 Memorial Circle, Lubbock, TX 79409, USA
5. Harvinder Singh Gill, Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA