共查询到20条相似文献,搜索用时 200 毫秒
1.
M. M. Asimov R. M. Asimov A. N. Rubinov S. A. Mamilov Yu. S. Plaksii 《Journal of Applied Spectroscopy》2006,73(1):99-102
We have studied the effect of temperature on laser-induced photodissociation of oxyhemoglobin in vivo by recording the change
in the oxygen saturation of arterial blood. We have established that on exposure to low-intensity laser radiation, the local
concentration of free oxygen in tissue significantly increases for a body temperature above 40°C, compared with the normal
temperature. We demonstrate a unique option for selectively and locally increasing the concentration of free molecular oxygen
in tissue, which promotes enhancement of cell metabolism. We consider the possibilities for biomedical use of this phenomenon.
The results obtained show that the temperature dependence of the quantum yield for photodissociation of oxyhemoglobin should
be considered in development of new therapeutic methods for laser medicine.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 90–93, January–February, 2006. 相似文献
2.
We propose and examine an optical method for eliminating the toxic effect of carbon monoxide. The developed method is based
on laser-induced photodissociation of carboxyhemoglobin in blood vessels and capillaries. By numerical simulation of the interaction
of laser radiation with tissue, we calculate the spectra of the action of carboxyhemoglobin and oxyhemoglobin in cutaneous
blood vessels. We show that, despite the sufficiently strong overlap of the action spectra of carboxyhemoglobin and oxyhemoglobin,
the substantial difference in the quantum yield values makes it possible to develop an optical method for eliminating the
toxic effect of carbon monoxide. We determine the criteria for the efficiency of laser-induced photodissociation of carboxyhemoglobin
under direct action on lung alveoli through the skin tissue and intravenously. 相似文献
3.
M. M. Asimov A. N. Korolevich E. É. Konstantinova 《Journal of Applied Spectroscopy》2007,74(1):133-139
We present the results of modeling the action spectrum and an experimental investigation of the effect of laser-induced photodissociation
of oxyhemoglobin in vivo on the increase in the degree of oxygenation of skin tissue in the exposed area. We have shown that controlling the local
concentration of free molecular oxygen in biological tissues together with the possibility of eliminating tissue hypoxia using
laser radiation makes it possible to stimulate aerobic cell metabolism and to achieve the needed therapeutic effect.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 120–125, January–February, 2007. 相似文献
4.
Light action spectra over wavelengths of 300–1000 nm are calculated for components of the human cutaneous covering: melanin,
basal (bloodless) tissue, and blood oxy- and deoxyhemoglobin. The transformation of the spectra with depth in biological tissue
results from two factors. The first is the wavelength dependence of the absorption coefficient corresponding to a particular
skin chromophore and the second is the spectral selectivity of the radiation flux in biological tissue. This factor is related
to the optical properties of all chromophores. A significant change is found to take place in the spectral distribution of
absorbed radiant power with increasing depth. The action spectrum of light for the molecular oxygen contained in all components
of biological tissue is also studied in the 625–645 nm range. The spectra are found to change with both the volume fraction
of blood vessels and the degree of oxygenation of the blood. These results are useful for analyzing processes associated with
optical absorption that are possible mechanisms for the interaction of light with biological tissues: photodissociation of
oxyhemoglobin and the light-oxygen effect. 相似文献
5.
V. V. Barun A. P. Ivanov A. V. Volotovskaya V. S. Ulashchik 《Journal of Applied Spectroscopy》2007,74(3):430-439
A three-layered skin model (stratum corneum, epidermis, and dermis) and engineering formulas for radiative transfer theory
are used to study absorption spectra and light penetration depths of normal and pathologically altered skin. The formulas
include small-angle and asymptotic approximations and a layer-addition method. These characteristics are calculated for wavelengths
used for low-intensity laser therapy. We examined several pathologies such as vitiligo, edema, erythematosus lupus, and subcutaneous
wound, for which the bulk concentrations of melanin and blood vessels or tissue structure (for subcutaneous wound) change
compared with normal skin. The penetration depth spectrum is very similar to the inverted blood absorption spectrum. In other
words, the depth is minimal at blood absorption maxima. The calculated absorption spectra enable the power and irradiation
wavelength providing the required light effect to be selected. Relationships between the penetration depth and the diffuse
reflectance coefficient of skin (unambiguously expressed through the absorption coefficient) are analyzed at different wavelengths.
This makes it possible to find relationships between the light fields inside and outside the tissue.
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Translated from Zhurnal Prikladnoi Spektroskopii Vol. 74, No. 3, pp. 387–394, May–June, 2007. 相似文献
6.
Mechanisms of photophysical, photobiological, and therapeutic action of light on blood in vivo are discussed based on results
of spectral and clinical studies of blood, plasma, and erythrocytes. Spectral manifestations of photochemical reactions initiated
in blood by therapeutic doses of radiation in vivo with light of different wavelengths are considered. Spectral and clinical
results of blood investigations are compared for patients whose complex treatment included intravenous blood irradiation and
magnetotherapy. Mechanisms for secondary (dark) reactions induced by the action of light on blood in vivo are discussed. The
radiation of laser and non-laser light sources used at present for intravenous blood irradiation (365, 405, 450, 530, 632,
635, 808 nm) is shown to fall within hemoglobin absorption bands. The conclusion is made that blood absorption of laser and
non-laser light radiation results in functional alteration of hemoglobin as a possible primary photoacceptor absorbing light
radiation of the above wavelengths. The therapeutic effect of intravenous blood irradiation is initiated by hemoglobin functional
activity modulation. Phototherapy is a means to correct it. Intravenous phototherapy should be considered as a therapeutic
method that changes (provided that the dosage is correct) the balance of active oxygen species production and their inhibition
by antioxidants.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 51–75, January–February, 2009. 相似文献
7.
L. G. Astafyeva R. Gade W. -D. Schmidt G. P. Ledneva U. Wollina D. Fassler 《Optics and Spectroscopy》2006,100(5):789-796
The spatial distribution of the energy absorbed by a unit volume of a laser-irradiated biological tissue is calculated by the Monte Carlo method. Based on these calculations, the temperature fields in biological tissues subjected to laser radiation at 810 nm are modeled. The temperature fields in subcutaneous blood vessels are modeled separately taking into account the inhomogeneous volumetric distribution of heat sources inside the vessels. The results of the modeling showed that laser heating can be efficiently used both for small-diameter and large vessels. Experimental clinical trials of therapy of vascular skin changes by pulsed diode laser radiation (at 810 nm) confirmed these results. 相似文献
8.
We have studied the ratio of the intensities of radiation scattered by a layer of blood in a cuvet and by the cuvet walls
for normal incidence or incidence at the Brewster angle for probing radiation from a He-Ne laser, linearly polarized in the
plane of incidence (plane of observation) or orthogonal to that plane. We have compared it with the intensity of the radiation
reflected by the surface of the cuvet wall, as estimated based on the geometric approximation. We have found the optimal conditions
for probing and observing scattering for the layer in a cuvet, where such conditions are characterized by a minimal effect
from the cuvet walls and the maximum ratio of useful signal to background.
Report given at the Fifth International Scientific and Technical Conference on Quantum Electronics, 22–25 November 2004, Minsk,
Belarus.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 270–272, March–April, 2006. 相似文献
9.
We present the results of a spectral study of the effect of low-intensity laser radiation on the molecular structure of blood
and blood components. Analysis of the Fourier transform IR absorption spectra of blood confirmed the changes we observed previously
in the oxygen transport characteristics of blood with intravenous exposure to the emission from a He-Ne laser. We show that
structural and conformational changes in the hemoglobin tetramer, initiated by laser-induced photoreactions between Hb and
oxygen, lead to characteristic changes in the shape and intensity of the IR bands for NH stretching vibrations, and also the
amide I and amide II absorption bands. In the IR spectra of irradiated blood samples, we note increased absorption in the
bands for stretching vibrations of the phosphate groups (945–1280 cm−1), which is evidence for an increase in the nucleic acid content (DNA, RNA). In the spectra of plasma and erythrocytes prepared
from irradiated blood, there are no changes in this region of the IR spectrum. At the same time, in the IR spectra of samples
of irradiated plasma, the intensity of the bands for stretching vibrations of the CH2 groups increases substantially.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 106–112, January–February, 2006. 相似文献
10.
We investigated the effect of the mode composition (longitudinal and transverse modes) of laser radiation on the basic parameters
of the stroke pattern formed on a treated surface placed inside a laser cavity. We found that the contrast of the stroke pattern
formed by a laser beam with a complex set of longitudinal modes depends, in the first place, on the width of the laser radiation
spectrum and the laser cavity length and is virtually independent of the angle of rotation of the beam. In the region of small
rotation angles the broadening of strokes caused by the effect of transverse modes becomes predominant.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikaladnoi Spektroskopii, Vol. 64, No. 1, pp. 50–54, January–February, 1997. 相似文献
11.
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. 相似文献
12.
We have obtained quantitative data on the differential (with respect to depth) and the integrated oxyhemoglobin photodissociation
efficiency in the dermis when the skin surface is exposed to a light beam in the wavelength range 300–650 nm. With this aim,
we have used our own previously developed optical model for skin tissue and analytical procedure for calculating the characteristics
of optical fields in a medium. We have estimated the number of oxygen molecules formed at different depths in the medium,
and also their integrated number over the entire thickness of the dermis as a function of the irradiation wavelength. We consider
models for a dermis that is homogeneous with respect to depth and a dermis that has a layered structure. We show that the
spectral photodissociation efficiency has a number of maxima associated with the absorption spectrum of oxyhemoglobin and
the optical properties of all the layers of skin tissue. We discuss the effect of the epidermis on these maxima. 相似文献
13.
N. S. Leshenyuk M. V. Prigun G. S. Kruglik N. S. Petrov 《Journal of Applied Spectroscopy》2006,73(2):251-258
Based on analysis of the properties of macromolecules in a coherent optical radiation field and taking into account experimentally
established data on the specificity of the interaction between laser radiation and biomolecules (the dependence of the efficacy
of the interaction on the coherence length, the presence of an effect in a region of the spectrum far away from the absorption
band), we propose a mechanism for wave interaction of coherent optical radiation with macromolecules, and we construct a very
simple mathematical model for such interaction. Using the mathematical model, we calculate the dependence of the vibrational
energy of the macromolecule in a coherent radiation field on the coherence time and the intramolecular relaxation rate. We
show that the increase in the vibrational energy of the macromolecules strongly depends on the radiation coherence length.
When exposed to incoherent radiation, the vibrational energy of the biomolecules remains practically constant, while when
exposed to laser radiation (coherence length ≈3 cm), the vibrational energy of the atoms increases by 2–4 orders of magnitude,
leading to a change in the conformation of the biomolecules and the activity of enzymes.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 225–231, March–April, 2006. 相似文献
14.
S. A. Bakhramov A. M. Kokhkharov U. K. Makhmonov O. R. Parpiev P. K. Khabibullaev 《Journal of Applied Spectroscopy》2009,76(1):82-88
We have experimentally studied for the first time the effect of photoinduced rotation of the plane of polarization for pulsed
laser radiation in solutions of C70 fullerene in organic solvents and their mixtures. We have shown that the effect is observed for elliptical polarization of
the laser radiation and is absent for linear polarization. We present the results of a study of the nonlinear optical characteristics
of the C70 solutions. We discuss the physical mechanisms by which nonlinear gyrotropy is induced in solutions.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 93–99, January–February, 2009. 相似文献
15.
We propose and examine a new approach to visualizing a local network of cutaneous blood vessels using laser optical methods
for applications in biometry and photomedicine. Various optical schemes of the formation of biometrical information on the
architecture of blood vessels of skin tissue are analyzed. We developed an optical model of the interaction of the laser radiation
with the biological tissue and a mathematical algorithm of processing of measurement results. We show that, in medicine, the
visualization of blood vessels makes it possible to calculate and determine regions of disturbance of blood microcirculation
and to control tissue hypoxia, as well as to maintain the local concentration of oxygen at a level necessary for the normal
cellular metabolism. We propose noninvasive optical methods for modern photomedicine and biometry for diagnostics and elimination
of tissue hypoxia and for personality identification and verification via the pattern of cutaneous blood vessels. 相似文献
16.
We have shown that brief exposure of sturgeon embryos (fertilized roe) in the organogenesis stage to low-intensity radiation
in the visible region of the spectrum can have a long-term effect on embryonic and post-embryonic development of the fish,
detectable 50 days after the irradiation procedure. The biological effects (size-weight characteristics and hardiness parameters
of the fish relative to unfavorable habitat conditions) induced by linearly polarized emission from a monochromatic laser
source (helium-neon laser, λ = 632.8 nm, Δλ ≈ 0.02 nm) and a quasi-monochromatic light-emitting diode (LED) source (maximum
in emission spectrum λ = 631 nm, Δ λ = 15 nm) are practically the same. Going to broadband linearly polarized radiation (λ
= 420–800 nm) is accompanied by a decrease in the biological effect.
From the results of studies of the effect on embryos from linearly polarized and unpolarized radiation from an LED source
and also the effect of linearly polarized, circularly polarized, and unpolarized radiation from a helium-neon laser, we concluded
that the type of polarization is of critical importance in realization of the biological effect of radiation. In this case,
the maximum stimulating effect (on the size×weight characteristics and the hardiness parameters for juvenile fish) is observed
on exposure to linearly polarized radiation; the photobiological effect induced in the same dose range by light with natural
polarization (i.e., unpolarized) is significantly less pronounced; the stimulating effect of circularly polarized radiation
occupies an intermediate position.
Based on the presented data and also on data obtained previously, we conclude that among the resonant and nonresonant photophysical
processes (orientational effect of light, effect of gradient forces, dipole-dipole interactions, thermooptic processes) capable
of inducing photobiological effects dependent on such laser-specific characteristics as polarization and coherence, the determining
influence in the processes studied in this work comes from the orientational effect of light and dipole×dipole interactions.
And the orientational effect can appear for anisotropic media with liquid-crystal type ordering (especially domains in membranes
and multiple-enzyme complexes) both under conditions when there is no resonant absorption and for weakly absorbing structures,
and can initiate a change in their conformations and accordingly their functional characteristics.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 843–858, November–December, 2008. 相似文献
17.
V. S. Burakov N. A. Savastenko N. V. Tarasenko E. A. Nevar 《Journal of Applied Spectroscopy》2008,75(3):394-401
Composite copper-containing carbon nanosized structures were synthesized in the plasma of a pulsed electrical discharge, initiated
between two graphite electrodes in an aqueous copper chloride solution. We studied the effect of laser radiation on the morphology
of the nanoparticles formed, whose properties we studied by optical absorption spectroscopy and transmission electron microscopy.
We discuss the mechanisms for nanoparticle formation in a discharge submerged in a liquid, and the possibilities for laser-induced
modification of the nanoparticles. We estimated the temperature of the nanoparticles when exposed to laser radiation pulses.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 372–378, May–June, 2008. 相似文献
18.
The method of diffusion-wave spectroscopy based on the analysis of fragments of temporal autocorrelation functions or power
spectra of intensity fluctuations of scattered coherent laser radiation is considered as applied to noninvasive in vitro diagnostics
of blood. The results of experiments on noninvasive diagnostics of blood in vitro are interpreted within the framework of
the theory of diffusion wave spectroscopy. The proposed method can be recommended for laboratory and clinical investigations
of formed blood elements.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 515–519, July–August, 2000. 相似文献
19.
R. Schützhold C. Maia 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(2):375-378
In addition to the Larmor radiation known from classical electrodynamics,
electrons in a laser field may emit pairs of entangled photons – which
is a pure quantum effect.
We investigate this quantum effect and discuss why it is suppressed
in comparison with the classical Larmor radiation (which is just
Thomson backscattering of the laser photons).
Further, we provide an intuitive explanation of this process
(in a simplified setting) in terms of the Unruh effect. 相似文献
20.
A. V. Kuptsova 《Journal of Applied Spectroscopy》2000,67(1):77-81
The spectra of Faraday rotation of the plane of polarization of laser radiation in strong radiation fields and a magnetic
field were investigated for alkali atoms. The spectra were obtained using the known method of computer simulation of polarization
effects in real multilevel atoms. The possibility of using these effects in the phase-polarization method of selection of
laser frequencies was considered.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 61–64, January–February, 2000. 相似文献