Based on a terahertz (THz) pipe-based near-field imaging system, we demonstrate the capability of THz imaging to diagnose freshly surgically excised human colonic tissues. Through THz near-field scanning the absorbance of the colonic tissues, the acquired images can clearly distinguish cancerous tissues from healthy tissues fast and automatically without pathological hematoxylin and eosin stain diagnosis. A statistical study on 58 specimens (20 healthy tissues and 38 tissues with tumor) from 31 patients (mean age: 59 years; range: 46 to 79 years) shows that the corresponding diagnostic sensitivity and specificity on colonic tissues are both 100%. Due to its capability to perform quantitative analysis, our study indicates the potential of the THz pipe-based near-field imaging for future automation on human tumor pathological examinations.
Based on a THz pipe-based near-field imaging system, we demonstrated the capability of THz imaging to diagnose human breast and liver cancers. Through THz near-field mapping of the absorption constants of cancer tissues, the acquired images can not only clearly distinguish cancer from normal tissues fast, automatically, and correctly without pathological H&E staining, but also identify the distribution region of cancer, which matches well with the identification with pathological examination. Due to its capability to perform quantitative analysis, our study indicates the potential of the THz pipe-based near-field imaging for future automation on human tumor pathological examinations and for quick definition of the tumor margins during the surgical procedure such as breast-conserving surgery. With the help of THz imaging, we can expect to economize the use of hospital and human resources.
Fourier transform infrared spectrometer and THz-TDS were used to obtain the experimental spectrum of glycine below 600 cm<sup>-1</sup>, and theoretical results of one or more zwitterionic glycine were calculated by DFT at the basis set of b31yp 6- 31+g(d,p) level based on Gaussian 03 software package in FIR region. There is more reasonable qualitative agreement between the calculated data of crystalline and observed line positions. Detailed assignments of the observed vibrational frequencies are discussed and the origins of some frequencies are analyzed by contrast. The low frequency collective mode of zwitterionic glycine is affected greatly by the intermolecular interaction and hydrogen-bonding effects and their vibrational modes are collective motion.
We used terahertz time-domain spectroscopy (THz-TDS) to probe the enhancement transmission of
Ag<sub>2</sub>O-Ag compound. Using a 500μm- GaAs substrate attaching to the sample, the evanescent wave
is coupled to the far field. And the transmitted amplitude is enhanced, corresponding to the frequent
shift and spectra broadening.