Optics and Spectroscopy最新文献

The method of static (non-flow) spectral digital microscopy (SSDM) method to identify, to count and to determine the standard and individual characteristics of native blood erythrocytes is suggested. The object to study was the whole donor blood diluted by saline and placed into the counting Goryaev camber. Among the standard characteristics of erythrocytes, the following were determined: the concentration of erythrocytes in a blood sample RBC (Red Blood Cells concentration), the scatter of erythrocytes by volume RDW (Red cells Distribution Width), including RDW-SD and RDW-CV, hematocrit HCT, mean erythrocyte volume MCV (Mean Cell Volume). n addition, the possibility of measuring the average hemoglobin content in erythrocyte MCH (Mean Cell Hemoglobin), MCHC (Mean Corpuscular Hemoglobin Concentration), as well as the total content of hemoglobin HGB in the blood sample (Hemoglobin) was investigated. The peculiarity of SSCM method proposed lies in the fact that it fundamentally allows to determine not only the general hematological characteristics of blood samples (RBC, RDW-SD and RDW-CV, HGB), but also the mean values of the characteristics of native blood erythrocytes (MCV, MCH, MCHC), and also, and most importantly, the individual characteristics of each erythrocyte. The latter permitted the authors to introduce a new type of erythrocyte characteristics ICV, ICH, ICHC (Individual Cell Volume, Individual Cell Hemoglobin, Individual Corpuscular Hemoglobin Concentration). In turn, this made it possible to obtain the histograms of hemoglobin distribution in erythrocytes of a blood sample along with the traditional distribution of their volumes, which can serve as an additional tool in the field of hemodiagnostics. Thus, the paper shows that SSCM method makes it possible to compile an individual metrological “passport” for each erythrocyte of the blood sample under study—this is the main feature of this work.

The luminescence excitation energy transfer in europium and terbium indole-3-carboxylates, indole-3-acetates and indole-3-propionates as well as ternary indolecarboxylates containing 1,10-phenanthroline and 2,2'-bipyridine molecules have been studied. The luminescence excitation spectra, the lifetimes of the ⁵D₀ (Eu³⁺) and ⁵D₄ (Tb³⁺) states, and the luminescence intensity are analyzed. The decisive role of ligand-metal charge transfer (LMCT) states in the quenching of the luminescence of europium aromatic carboxylates containing a π-excessive pyrrole or indole fragment is demonstrated. Most europium compounds are characterized by quenching due to the depopulation of the ⁵D₀ state of the Eu³⁺ ion through the low-energy LMCT state. But in some ternary compounds, the LMCT state being of higher energy participates in the nonradiative depopulation of the excited electronic states of the ligand.

Influence of light exposure duration (model 18 : 6) on hormonal indices of stress-implementing system in laboratory animals blood is studied. Activity of stress systems central link was evaluated based on data on concentration of adrenocorticotrophic hormone, melatonin and β-endorphin in blood serum, observed during enzyme immunoassay. Reaction of peripheric link of the stress-implementing system was evaluated in blood smears based on results of qualitative count of catecholamine granules in erythrocytes. It was established, that variations of hormonal indices of the stress systems for laboratory animals depend on trigger factor activity periods. With increase of the experiment duration to 21st days the most pronounced reduction of melatonin, β-endorphin and increase of adrenocorticotrophic hormone concentration, as well as sharp increase of catecholamines level are observed in the blood serum. These hormonal changes develop as a result of failure of compensation mechanisms of the stress-implementing systems in connection with melatonin rhythms disturbance, that indicates the gradual development of the general adaptation syndrome.

A study of high-NA focusing process of ultrashort laser pulses in bulk of ZnSe has been carried out. It is shown that when focusing laser Gaussian beam with high-aperture lenses into a transparent medium aberration distortions occur leading to an increase in focal spot size. The results of experimental studies on ablation of front and back surfaces of a plane-parallel plate with 4 mm thickness made of ZnSe by laser pulses with a duration of 0.3, 1, 10 ps and a wavelength of 1030 nm focused by a micro lens (NA = 0.55) are presented. It is shown that at low pulse energies focusing can be considered in a linear mode in which focal spot size is due to aberration distortions.

An efficient pulsed gas-discharge inductive CO₂-laser with a radiation energy of 1.05 J has been developed for the first time. In this case, the pulse duration of the laser radiation was about 10 ms. The maximum efficiency of 21.1% was obtained at a radiation energy of 340 mJ. HF current pulses propagated along the inductor conductor and, thus, an inductive discharge was formed to create a population inversion at the infrared (IR) transitions of CO(_{2}^{*}) molecules. The temporal and energy characteristics of the radiation of the inductive CO₂-laser depending on the duration of the pump pulse are investigated. The spatial characteristics and spectrum of the radiation of the developed laser are estimated. The divergence of the laser radiation was 0.52 mrad. The cross-sectional dimension of the laser output beam was about 35 mm in diameter.

Crystals of the concentration series ZrO₂–(8–10) mol % Sc₂O₃–(1–2) mol % Tb₂O₃ were grown by the method of directional crystallization of the melt from a cold container. Analysis of the spectral-luminescence characteristics of these crystals after growth and after annealing processing in a vacuum revealed the presence of both Tb³⁺ and Tb⁴⁺ ions in them. In crystals ZrO₂–(8–10) mol % Sc₂O₃–(1–2) mol % Tb₂O₃, the presence of a process of non-radiative energy transfer from Tb⁴⁺ ions to Tb³⁺ ions was revealed.

A formula for calculating the relativistic electron localization function (RELF) within the framework of the Dirac–Fock method is obtained. An approach similar to that used earlier in [A.D. Becke and K.E. Edgecombe, The Journal of Chemical Physics 92, 5397 (1990)] in deriving an expression for the nonrelativistic electron localization function (ELF) is applied. It is demonstrated that the expression for RELF differs from the expression for ELF with replacement of the nonrelativistic electron density by its relativistic counterpart. Relativistic calculations of ELF and RELF for a number of superheavy elements are performed and the results are compared. By several examples it is shown that the ELF value equal to 0.5 does not necessarily correspond to the distribution density of homogeneous electron gas.

Using the method of dynamic light scattering, it was found that the rate of collagen cleavage under the influence of bacterial collagenase decreases by almost 4 times when protein molecules are doped with Cr³⁺ ions, and when the enzyme activator of Zn²⁺ ions is added, it increases by 1.3 times. Based on the experimental data, the reaction rate constants k₁ were calculated. It was found that when collagen molecules are tanned with a chromium salt, it becomes more resistant to degradation in solutions containing zinc ions than in solutions with the addition of calcium ions, as we described in earlier works.

Regeneration of cartilaginous tissue and its shape change at laser exposure can be used as a basis for prospective medical operations, improving patient’s quality of life. The most important criterion of such operations success is a cell survival after laser exposure, therefore reduction of exposure duration and power is an important task at such methods development. Nanoparticles are actively used in medicine, and one of their intended usages is photothermal effect enhancement at laser exposure to biological tissue. However, articular tissue is quite resistant to foreign agents penetration, therefore the study of nanoparticles penetration capability and their impregnation effect is the priority task for achieving the desired medical effect. Optical coherence tomography (OCT) of gel phantoms and cartilaginous tissue of a joint, impregnated with nanoparticles, at laser exposure with erbium fiber laser with length wave of 1.56 μm is performed in this study. Articular cartilaginous tissue sections of three types (intact, with laser damage and after low laser exposure) were impregnated with nanoparticles of Fe₃O₄ for further study using OCT elastography. Increase of deformations, caused by heating of phantoms and tissue, impregnated with nanoparticles, is observed. OCT elastography data indicate the dependence of tissue deformation on previous tissue exposure history. The work substantiates increase of photothermal impact of laser exposure to tissue deformation at various nanoparticles introduction.

ZnAl₂O₄ nanocrystallites doped with Cr³⁺ ions with mean sizes ranging from 2 to 16 nm were synthesized by the hydrothermal method. Chromium ions occupy the aluminum positions, which symmetry depends on the crystallite size. The smallest nanocrystals have a much larger unit cell than the bigger ones. The metal to ligand distance increases when the size of the nanocrystals decreases. This causes the nephelauxetic effect, which is for the first time (to our knowledge) observed as a size effect. It was also observed that ZnAl₂O₄:Cr³⁺ nanocrystals with size larger than 10 nm possesses the same spectroscopic properties as monocrystal.