IR Spectroscopic signs of malignant neoplasms in the thyroid gland

We use Fourier transform IR spectroscopy to study thyroid tumor tissues which were removed during surgery. The IR spectra of the tissues with pathological foci are compared with data from histologic examination. In the region of N–H, C–H, and C = O stretching vibrations, the IR spectra of the tissues for thyroid cancer are different from the IR spectra of tissues without malignant formations. We identify the spectral signs of thyroid cancer. We show that IR analysis is promising for identification of thyroid pathology at the molecular level.     

Improving information content of images of vegetation objects using spectral data

We propose a calculation procedure for obtaining multispectral images in remote sensing of vegetation objects in the spectral range 400–1000 nm, based on three-channel spectral zonal images and reference spectra measured at several points of the recorded scene. The procedure makes it possible to improve the information content of the data for solving various thematic classification problems. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 670–676, September–October, 2007.     

Measurement of the space–time interval between two events using the retarded and advanced times of each event with respect to a time-like world-line

Several recent studies have been devoted to investigating the limitations that standard quantum mechanics and/or quantum gravity might impose on the measurability of space–time observables. These analyses are often confined to the simplified context of 2D flat space–time and rely on a simple procedure for the measurement of space-like distances based on the exchange of light signals. We present a generalization of this measurement procedure applicable to all three types of space–time intervals between two events in space–times of any number of dimensions. We also present a preliminary account of an alternative measurement procedure that can be applied taking into account the gravitational field of the macroscopic measuring apparatus.     

Infrared spectra of proteins and lipids in human breast malignant tissues

IR spectroscopy methods have been adopted for investigating resected tissues of mammary glands. IR spectra of surgical material are compared with histological data. Spectra of proteins and lipids in malignant tumors are shown to be different from those in benign tumors and in tissues outside the pathologically impacted volume. Differences in the protein spectra are due to changes in the supramolecular structure because of the cleavage of intramolecular C=O⋅⋅⋅H–N H-bonds. Spectral signatures of malignant pathologies are identified. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 261–266, March–April, 2009.     

Synthesis and luminescence of a folic acid-europium chelate conjugate

We have synthesized a folic acid–europium complex conjugate which shows promise for biomedical applications. We have studied the absorption spectra, the luminescence spectra, and the luminescence excitation spectra of folic acid–spacer–amino-substituted phenanthroline and folic acid–spacer–europium chelate conjugates, and also of the individual components of the synthesized triads. All the spectral luminescence data obtained confirm that a folic acid–europium complex conjugate is fogrmed. Binding of the synthesized conjugate to a folate receptor on HeLa tumor cells is demonstrated.     

Formation of SERS-active silver structures on the surface of mesoporous silicon

We have optimized the procedure for preparation of nanostructured silver films on the surface of mesoporous silicon (PSi) to use them as active substrates in surface-enhanced Raman scattering (SERS) spectroscopy. The greatest enhancement of the SERS signal was observed for samples obtained when the silver was deposited on PSi from an aqueous AgNO₃ solution with concentration 1⋅10^–2 M over a 10–15 minute period. The detection limit for rhodamine 6G on SERS-active substrates prepared by the optimized procedure was 1⋅10^–10 M. The enhancement factor for the SERS signal on these surfaces was estimated as ≈2⋅10⁸. We have shown that SERS-active substrates based on mesoporous silicon are promising for detection and study of complex organic compounds, in particular tetrapyrrole molecules. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 298–306, March–April, 2009.     

Procedure for retrieval of atmospheric aerosol backscatter coefficient profiles from results of multi-wavelength lidar sounding

A measurement procedure is proposed to retrieve the profiles of atmospheric aerosol backscatter coefficients (β_a) from the results of multi-wavelength sounding of the atmosphere by a laser location system based on a Nd: YAG-laser. The procedure uses a regression dependence between spectral values of β_a (background aerosol model) and involves the determination of coefficients which characterize the relative spectral behavior of aerosol extinction. The stability of the procedure to spatial variations of the above coefficients, a deviation of β_a from the dependence used, and calibration and measurement errors is examined. This procedure is compared with the widely used Fernald method by means of a numeric experiment. This procedure is demonstrated to be effective for retrieving vertical profiles of β _a in the troposphere, especially in the short-wavelength region. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 347–353, May–June, 2008.     

Imaging of subcutaneous blood vessels and flow velocity profiles by optical coherence tomography

We have applied a compact low power rapid scanning Doppler Optical Coherence Tomography system to monitor multi-dimensional velocity profiles within the complex vessels and simultaneous real-time non-invasive imaging of skin tissues morphology in vivo, in the wavelength range of 1.3–1.5 nm. Optical clearing of skin tissues has been utilized to achieve depth of OCT images up to 1.7 mm. Current approach enables applying low-power (0.4–0.5 mW) and low-noise broadband near-infrared light sources and obtaining OCT images with down to 12 μm spatial resolution. Two-dimensional time-domain OCT images of complex flow velocity profiles in blood vessel phantom and in vivo subcutaneous human skin tissues are presented. The effect of optical clearing on in vivo images is demonstrated and discussed.     

X-ray fluorescence analysis of Ni–Fe–Mn/Cr systems

We have developed a procedure for x-ray fluorescence determination of the constituent composition and thickness of two-layer Ni–Fe–Mn/Cr films deposited on Polikor, an aluminum oxide ceramic. We have calculated correction coefficients taking into account interelement interference effects in this system. We have experimentally determined the density of the materials making up the composition of the films. We have established and present the metrological characteristics of the procedure developed.     

Application of the differential method for determining the composition of a toluene-methyl ethyl ketone mixture by an IR analyzer

A differential method is suggested to analyze two-component systems. It allows a 1.5-fold increase in sensitivity as compared to the ordinary procedure for determination of the composition of toluene-methyl ethyl ketone by an 1R continuous-flow analyzer. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 408–409, May–June, 1999.     

Whole-body distribution of <Superscript>14</Superscript>C-labeled silica nanoparticles and submicron particles after intravenous injection into Mice

We analyzed the whole-body distribution of ¹⁴C–ADP-labeled silica nanoparticles (¹⁴C–ADP–SiO₂ nanoparticles) and submicron particles (¹⁴C–ADP–SiO₂ submicron particles) after intravenous injection into ICR mice. The ¹⁴C–ADP–SiO₂ nanoparticles and submicron particles were synthesized before the injection and the particle size was 19.6 and 130 nm, respectively. Similarly, the shape was spherical and the crystallinity was amorphous. After the synthesis, we injected mice with the ¹⁴C–ADP–SiO₂ nanoparticles or the ¹⁴C–ADP–SiO₂ submicron particles and dissected tissues after 1, 2, 4, 8 and 24 h. The radioactivity in the tissues was measured with a liquid scintillation counter. As a result, the retention percentage in bone, skin, lymph nodes, and the digestive mixture was at least twofold higher in the ¹⁴C–ADP–SiO₂ nanoparticles-exposed mice, whereas the retention percentage in the kidney was statistically higher in the ¹⁴C–ADP–SiO₂ submicron particles-exposed mice. Both types of ¹⁴C–ADP–SiO₂ particles mainly translocated to the muscle, bone, skin, and liver, but hardly translocated to the brain and olfactory bulb. Furthermore, the ¹⁴C–ADP–SiO₂ nanoparticles had a higher retention percentage (62.4 %) in the entire body at 24-h post-injection than did the ¹⁴C–ADP–SiO₂ submicron particles (50.7 %). Therefore, we suggested that the ¹⁴C–ADP–SiO₂ nanoparticles might be more likely than the ¹⁴C–ADP–SiO₂ submicron particles to be retained in the body, and consequently they might be gradually accumulated by chronic exposure.     

FTIR study of zinc-induced biochemical changes in the liver of Indian carp <Emphasis Type="Italic">Labeo rohita</Emphasis>

Zinc is an essential metal for different physiological functions and becomes toxic when elevated concentrations are introduced into the environment. In the present study, an attempt is made to analyze zinc-induced biochemical changes in the liver tissues of freshwater fingerlings of Labeo rohita using Fourier Transformation Infrared Spectroscopy. Several important features have been observed in the FTIR spectra of zinc-intoxicated liver tissues, namely, altered membrane lipid, altered protein profile, and increased glycogen content, indicating an alteration in the lipid and protein profiles leading to modification in membrane composition. Further, it is observed that acute exposure to zinc causes some alteration in protein profile with a decrease in α-helix and an increase in random coil structure. Treatment with the chelating agent D-penicillamine reduces the biochemical contents in the liver tissues. This shows that D-penicillamine is a good antidote for zinc toxicity. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 746–752, September–October, 2008.     

Spectroscopic analysis of bladder cancer tissues using Fourier transform infrared spectroscopy

Bladder cancer is one of the most common cancers in Africa. It takes several days to reach a diagnosis using histological examinations of specimens obtained by endoscope, which increases the medical expense. Recently, spectroscopic analysis of bladder cancer tissues has received considerable attention as a diagnosis technique due to its sensitivity to biochemical variations in the samples. This study investigated the use of Fourier transform infrared (FTIR) spectroscopy to analyze a number of bladder cancer tissues. Twenty-two samples were collected from 11 patients diagnosed with bladder cancer from different hospitals without any pretreatment. From each patient two samples were collected, one normal and another cancerous. FTIR spectrometer was used to differentiate between normal and cancerous bladder tissues via changes in spectra of these samples. The investigations detected obvious changes in the bands of proteins (1650, 1550 cm^–1), lipids (2925, 2850 cm^–1), and nucleic acid (1080, 1236 cm^–1). The results show that FTIR spectroscopy is promising as a rapid, accurate, nondestructive, and easy to use alternative method for identification and diagnosis of bladder cancer tissues.     

Modeling laser irradiation conditions for mucosal tissues in antimicrobial photodynamic therapy

We use computer modeling to analzye empirically selected conditions for antimicrobial photodynamic therapy of mucosal tissues. We calculate the optical and thermal fields for experimental conditions for low-intensity (cold) laser irradiation used in treatment of lesions in mucosal tissues stained by methylene blue: λ = 670 nm, power density 150–300 mW/cm², doses 9–18 J/cm²; λ = 632.8 nm, 15 mW/cm², dose 4.5 J/cm². For numerical estimates, we used the optical characteristics of methylene blue and three layers of mucosal tissues at the laser radiation wavelengths, and also the thermal characteristics of the tissues. The experimental conditions were optimized using the ratio of the tissue penetration depth for the absorbed optical energy and the penetration depth of methylene blue into the lesion, while maintaining safe tissue heating temperatures.     

Regaining profiles of extinction coefficients of optically dense scattering media in laser location measurements

We suggest a procedure for regaining spectral values of the extinction coefficients ε(r) of optically dense scattering media in laser location measurements. Allowance is made for the contribution of multiple scattering to a recorded signal and its correction for the degree of change of the qualitative composition of the scattering medium. The procedure can increase the accuracy of regaining ε(r) and eliminate the “edge effect” at the end of the probed path. The latter is achieved by determining a calibration constant from the transparency value of the whole probing range, which is calculated from back-scattered signals corrected based on the constancy of the lidar ratio. We present an algorithm for calculating the correction coefficient. The efficiency of regaining profiles of ε(r) is estimated using the atmospheric situation of a pure atmosphere and an extended smoke cloud arising from forest fires as an example. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 522–527, July–August, 2007.     

Luminescence analysis of blood components in studies of the neuroprotective properties of the drug “Semax” in cerebral ischemia

Luminescence-spectral analysis is used to study the neuroprotective effect of the drug Semax on the level of oxidative stress in cerebral tissues during cerebral ischemia through estimation of the free-radical damage to low density lipoproteins in animal blood serum. It is found that Semax decreases the oxidative stress in cerebral tissues during ischemia by reducing the production of free-radical compounds owing to activation of an inflammation line of protection for the organism. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 131–137, January–February, 2009.     

Bilinear optical susceptibilities of potassium dihydrogen phosphate and of III–V,II–VI and I–VII semiconductors

The approximate orbital-approach of Jha and Bloembergen is used to calculate the non-dispersive part of the bilinear optical susceptibility,χ ⁽²⁾, for various compounds. Using bonding and antibonding states of the molecular orbital theory it is shown thatχ ⁽²⁾ satisfies a simple relation in terms of other measurable physical quantities. This relation is used to calculateχ ⁽²⁾ for various III–V, II–VI and I–VII semiconductors, both with cubic zinc blende structure and with hexagonal wurtzite structure. The same procedure is used to obtainχ ⁽²⁾ for potassium dihydrogen phosphate (KDP). The calculated values are compared with the experimentally observed values and it is found that the present model gives excellent results for II–VI compounds and for KDP.     

Renormalization beyond the framework of the perturbation theory

By the example of a scalar field model with ϕ⁴ interaction, the possibility of separating the finite parameters beyond the framework of standard (in the interaction representation) perturbation theory is discussed. A scheme of divergence separation for large momenta and their compensation by infinite initial parameters – mass and coupling constant – is examined. The one-particle sector of the diagonal component of the total Hamiltonian admits this procedure. In this case, the energy of the one-particle spectrum has a relativistic form.     

Device for UV irradiation of blood with a disposable blood flow system

A device for extracorporal irradiation of blood by UV light with λ=300–400 nm is described. A disposable blood flow system with a specially profiled polymer cuvette is proposed. Mixing of blood during irradiation ensures uniform irradiation of blood cells passing through the cuvette, which makes it possible to enhance the healing effect of the procedure. B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 289–292, March–April, 1999.     

Adjustment of radiation spectrum of injection lasers by doppler-signal optical heterodyning

A procedure for changing the spectral characteristics of injection lasers by Doppler-signal optical heterodyning by changing the injection current is discussed. Results of current tuning of the radiation frequency, coherence, and other characteristics of AlGaAs-heterolasers by using the above procedure under conditions of c.w. lasing are reported. Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 503–508, July–August, 1998.