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.
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.
THz-TDS are used to study four kinds of drug: cortisone, hydrocortisone, prednisone and prednisolone. The THz spectra
of them are obtained and analyzed from 0.2 - 1.6 THz. The experimental results shows the four samples have the
different THz spectra. Cortisone has a peak at 1.5 THz and a broad absorption peak at 0.96 THz, while hydrocortisone
has a weak absorption peak that lies at 1.27 THz. At the same time the prednisone has the stronger absorption peaks than
the others, and its two peaks shows at 1.24 THz and 1.5 THz. Prednisolone has a weak broad peak at 1.43 THz. The
results of the theoretical calculation were performed using Gaussian 03 software with Density Functional Theory at the
basis set of 6-31+G (d, p). The theoretical vibrational frequencies are compared with the experimental results, and the
deviations are discussed. The THz spectra of the medicine show THz technique may be help to distinguish some
different chemical bond and functional group.
In this paper, THz-TDS has been used to measure the spectral properties of two active ingredients of Herba Ephedrae:
ephedrine and pseudoephedrine, which exist in hydrochloride salts. The THz spectra of the sole-ingredient, twoingredient
and three-ingredient compounds are studied. We obtained the finger-print spectra of the net active ingredients of the medicine, and also measured the mixtures of by two or three active ingredients at the different ratios. At the same time, theoretical analysis and quantitative analysis is applied to foretell the different THz spectra, identify the ingredients and infer the contents of principal components in samples. The THz spectroscopy is a potential and promising technique in evaluating and inspecting the quality of the drugs in the TCM field.
Absorption spectra and index of refraction of aminophenol compounds are obtained using Terahertz time-domain
spectroscopy (THz-TDS) in the frequency range between 0.3 and 2.0 THz at room temperature. Quantum chemical
calculations are performed to better understand the origin of the absorption features observed in experiments. Different
weight ratios of isomeric mixtures are analyzed by THZ-TDS with the help of linear regression technology. It is
concluded that THZ-TDS is able to identify the components and their relative percentage in isomeric mixtures.
Terahertz spectroscopy has tremendous potential for applications to evaluate the quality of the drugs including the TCM.
In this paper, the Terahertz Time-Domain Spectroscopy investigated two active ingredients: Andrographolide and
Dehydroandrographoline, isolated from Andrographis paniculata (Burm. f.) Nees. We also measured the mixtures of two
active ingredients at the different ratio and the quantitative analysis is also applied to determine the contents of
compound. The Terahertz spectroscopy is a potential and promising technique in identifying the components, evaluating
the drugs sanitation and inspecting the quality of medicine including TCM.