1. UNAM Institute of Material Science and Nanotechnology; Bilkent University; Ankara 06800 Turkey
2. Department of Electrical and Electronics Engineering; Atilim University; Ankara 06830 Turkey
3. Canary Center at Stanford for Cancer Early Detection; Department of Radiology; Stanford School of Medicine; Palo Alto CA 94304 USA
4. E. L. Ginzton Laboratory; Stanford University; Stanford CA 94305 USA