Raman spectral properties of squamous cell carcinoma of oral tissues and cells

Early diagnosis is the key of the improved survival rates of oral cancer. Raman spectroscopy is sensitive to the early changes of molecular composition and structure that occur in benign lesion during carcinogenesis. In this study, in situ Raman analysis provided distinct spectra that can be used to discriminate between normal and malignant tissues, as well as normal and cancer cells. The biochemical variations between different groups were analyzed by the characteristic bands by comparing the normalized mean spectra. Spectral profiles of normal, malignant conditions show pronounced differences between one another, and multiple Raman markers associated with DNA and protein vibrational modes have been identified that exhibit excellent discrimination power for cancer sample identification. Statistical analyses of the Raman data and classification using principal component analysis (PCA) are shown to be effective for the Raman spectral diagnosis of oral mucosal diseases. The results indicate that the biomolecular differences between normal and malignant conditions are more obviously at the cellular level. This technique could provide a research foundation for the Raman spectral diagnosis of oral mucosal diseases.     

Ultrasonic backscatter from bovine tissues: variation with pathology

This is the second in a series of two papers reporting results collected on ultrasonic propagation properties, namely, velocity, attenuation, and backscatter of various mammalian tissues. In the first paper [J. Acoust. Soc. Am 78, 871 (1985)], the experimental results of five different types of normal bovine tissues were given. In this paper, results obtained for the most common bovine disease in the liver, liver abscess, and in the heart, lymphosarcoma, will be presented. These data show that the ultrasonic properties of tissues with these two types of pathologies are significantly deviated from those of normal tissues, thus providing further evidence that ultrasonic properties may be used as quantitative indicators of a certain disease for diagnostic purposes.     

Correlation-induced spectral changes in tissues

We report experimental evidence of correlation-induced spectral changes in biological tissues. The overall spectral shift in our transmission measurements is to the red and the mean wavelength of the original spectrum is up 10% larger. These results indicate that the spectral changes due to elastic scattering are significant and likely to hinder all spectroscopic measurements based on the inelastic (i.e., emission and absorption) interaction between light and tissues. Thus, simultaneous morphology and spectral measurements are required for accurate measurements spectroscopic information.     

Fluorescence lifetime-enhanced spectral characterization of human serum

Frequency-domain fluorescence lifetime techniques were used for the characterization of pooled human serum, including normal serum, hyperlipid serum, and sera that had been stripped of various components. Fluorescence lifetime measurements of normal human serum revealed lifetime components primarily in the regions of 10² ps, 1–2 ns, 4–7 ns, and 9–10 ns. Phase-resolved fluorescence spectroscopy (PRFS), a frequency-domain technique that combines spectral and lifetime information, in measurements of phase-resolved fluorescence intensity (PRFI), provided the basis for comparison of the various sera. Measurements of PRFI vs excitation wavelength and emission wavelength yield a phase-resolved excitation-emission matrix (PREEM) at a given modulation frequency. Multifrequency measurements yield a three-way excitation-emission-frequency array. The multifrequency PREEMs of the various sera were compared with each other and with the corresponding two-way excitation-emission matrices (EEMs) that are obtained using conventional, steady-state fluorescence spectroscopy. Application of matrix-based analysis techniques to the steady-state and PRFS data arrays allowed direct comparison between the two approaches. Results demonstrate the enhanced discrimination among samples that is achieved through the additional dimension of fluorescence lifetime in PRFS.     

Optical absorption and scattering spectra of pathological stomach tissues

Diffuse reflection spectra of biotissues in vivo and transmission and reflection coefficients for biotissues in vitro are measured over 300–800 nm. These data are used to determine the spectral absorption and scattering indices and the scattering anisotropy factor for stomach mucous membranes under normal and various pathological conditions (chronic atrophic and ulcerous defects, malignant neoplasms). The most importan tphysiological (hemodynamic and oxygenation levels) and structural-morphological (scatterer size and density) parameters are also determined. The results of a morphofunctional study correlate well with the optical properties and are consistent with data from a histomorphological analysis of the corresponding tissues.     

Heat transport properties within living biological tissues with temperature-dependent thermal properties

Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explored in this paper. Taking into account of variable physical properties, the governing equation of temperature is first derived in the context of the dual-phase-lags model (DPL). An effective method, according to the Laplace transform and a linearization technique, is then employed to solve this nonlinear governing equation. The temperature distribution of a biological tissue exposed to a pulsed heat flux on its exterior boundary, which frequently happens in various heat treatments, is predicted and analyzed. The results state that a lower temperature can be predicted when temperature dependence is considered in the heating process. The contributions of key thermal parameters are different and dependent on the ratio of phase lag and the amplitude of the exterior pulsed heat flux.     

Infrared spectral radiative properties of high temperature gas with multi-component

The shock layer of high-speed missiles is a highly uneven gas medium with multi-component and high temperature. Its spectral radiation effects degrade and distort the remote sensing images of infrared sensors. The exact numerical calculating method of the shock wave thermal radiation noise has been developed in this paper. With the multi-temperature model and the rectangular grid recursive method of ray tracing, atomic-molecular absorption and emission spectra of CO₂, H₂O and N₂ were obtained along the line of sight along the seeker detectors. Based on image degradation evaluation criteria and the wind tunnel experimental results, how images blurred by the proposed model were verified. The relations between the shock wave thermal radiation noise and flow parameters were also analyzed. For the 3–8 μm infrared band, shock wave thermal radiation noise is little effected by flight altitude, and close relations with Mach number, as the empirical formula given.     

炼油废水的荧光指纹特征

荧光有机物携带了有机物总量和组成信息,可作为新型水质参数来弥补COD和BOD等不能表达有机物组成的不足。炼油废水是典型的难降解工业废水,含有大量有毒化合物。我国某大型炼油企业废水的三维荧光光谱的研究结果表明,炼油废水的荧光光谱与水样一一对应;荧光强度很高,主要由λex/λem=270/300nm,220/300nm和230/350nm附近的荧光峰叠加而成,其中270/300nm的荧光强度最大,220/300nm稍弱;各峰的位置和荧光强度对于炼油废水是稳定的。炼油废水的荧光包含了产物和原料的信息。苯酚对270/300nm,220/300nm附近的荧光峰的荧光强度贡献显著,而二氯苯和苯等其他单环化合物对这两峰可能也有贡献。230/350nm附近的荧光峰可能与烷烃和苯有密切关系。各峰的位置和荧光强度可以作为炼油生产以及废水处理厂来水是否正常的判据。     

Fluorescence properties of natural eumelanin biopolymer

Results about fluorescence spectroscopy of natural eumelanin are presented and compared to analogous results related to synthetic eumelanin, with the aim to investigate the structural organization of eumelanin and the role of the protein coat in its optical and structural properties. The spectra of synthetic and natural eumelanin have similar optical spectra, except for the features related to proteins in natural eumelanins. Fluorescence due to ensembles of large oligomer systems has been spectrally distinguished from that due to monomers and small oligomer systems. Nonetheless, the natural (protein-containing) eumelanin results to consist of aggregates having a larger size than that of synthetic eumelanin.     

Fluorescence properties of the dye-intercalated smectite

The fluorescence properties of the dye Rhodamine 590 and Rhodamine 640 intercalated into montmorillonite were studied. All of the intercalation reactions were accomplished in an ethanol solution which contained the corresponding quality of Rhodamine. The TG-DTA and the X-ray diffraction data showed that the immobilization of Rhodamine depended on the amount of ethanol incorporated in the interlayer space of montmorillonite. The 14.8 Å basal spacing of products indicated a conformation of Rhodamine with the xanthene nucleus and the phenyl group positioned parallel and perpendicular to the silicate layer, respectively. Also, the infrared pleochromism, which supported the proposed orientation of the phenyl group, was observed at 1250 and 712 cm⁻¹. The main fluorescence bands of both products were observed near 600 nm when excited by the 514.5 nm line of an argon ion laser. The results indicated that the mesomeric structure determined the fluorescence behavior, which was little different for the two products owing to the environment of the interlayer. These data are briefly discussed relative to the reaction conditions utilized for the synthesis of products. Also, the results support the idea that the products have a high potential for use as a host for a tunable laser.     

Fluorescence and persistent spectral hole burning of Eu in Ge-Ga-S-KBr glasses

Fluorescence and efficient persistent spectral hole burning of Eu³⁺ at 77 K were observed in chalcohalide glasses. The depth of the hole was approximately 30% after a burning process of 1 min with 50 mW power, and it was completely erased with Ar⁺ laser irradiation. The hole survived room temperature heat treatment and showed good thermal stability. The hole-burning mechanism was most probably the photo-reduction of Eu³⁺→Eu²⁺. Fluorescence from Eu³⁺ decreased with increasing temperature and disappeared at the temperature above ∼130 K.     

On spectral properties ofq-oscillator operators

The property of self-adjointness of the operatorQ =a ₊ +a _- in three types ofq-oscillator algebras is considered. Spectral measures and generalized eigenfunctions ofQ are found in the cases when this operator is bounded. Generalized eigenvectors are expressed in terms ofq-Hermite polynomials. If the operatorQ is unbounded, then its closure is not self-adjoint. However, in this case, admits self-adjoint extensions. Deficiency subspaces are one-dimensional. These subspaces are explicitly found.     

Biomechanical properties of soft tissues

Viscoelasticity is the primary mechanical property of bio-soft tissues. It has been widely applied in basic research of biological tissues including cornea, lung, heart and blood vessels. Along with the development of tissue engineering research, the evaluation of soft tissue viscoelasticity is becoming more and more important. In this paper, using the Whittaker function, we give an approximate power series of the exponential integralE ₁(X) and the parametersC, ?₁ and ?₂ of the generalized relaxation functionG(t) and generalized creep functionJ(t). With expanded skin as an example, the relationship between stress relaxation, creep and stress-strain finite deformation are studied.     

Structure and spectral properties of triphenylamine dye functionalized with 3,4-propylenedioxythiophene

Based on the density functional theory with the B3LYP, BMK, and PBE1PBE hybrid functionals and 6?C31G(d) atomic-orbital basis set, the structure and electronic-spectral properties of a triphenylamine dye sensitizer for photoelectric converters that is functionalized with 3,4-propylenedioxythiophene have been studied. The nature of an intense color of the sensitizer is elucidated. The relation of the orbital structure of the first excited state to the mechanism by which the intensity and polarization of the visible absorption band are formed, as well as the electron injection efficiency into the conduction band of titanium oxide, are explained. In terms of the Bader theory, a complete analysis of the electron density distribution in the dye molecule under study has been performed and the role played by nonvalent interactions in its stabilization has been determined.     

Features of applying fiber-optic sensors in spectral measurements of biological tissues

The fiber-optic sensor is a key element for in vivo spectral measurements of the diffusion reflection of biotissues. Its construction and geometry of the detection of light emerging from the biotissue have a significant effect upon the spectral composition of the detected light. This work presents the results of theoretical and experimental studies of the effect of the detection area on the spectral composition of diffusion reflection of skin. It was found that significant losses took place when detecting the light of the red and near-infrared light ranges if the dimensions of the detection area were comparable with the dimensions of the illuminated skin. The losses can be minimized with an increase in the detection area up to dimensions exceeding those of the illuminated skin by a factor of 3–4. In this case, losses during detection of the long-wavelength spectral range of light diffusely reflected by the skin are less than 5%.     

Determination of optical properties of tissues

Recent results and used way of tissue optical properties measurements in vitro with laser goniophotometer are presented. The optical properties were obtained on the basis of an indirect technique using solution of the radiative transfer equation, which relate the optical parameters of tissue with the measured parameters of reflected and transmitted radiation. The angular patterns of reflected and transmitted radiation by optically thick saline-soaked samples of tumor tissue, namely, mammary fibroadenoma, were measured at the wavelength of 0.63 μm, and the measurement data were inverted to find the absorption and extinction coefficients and the parameters of the phase function of these tumor samples. Obtained values of the optical parameters have been found to be of the same order of magnitude as the earlier reported data for similar tumor samples.