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We analyzed the distribution of the ordering parameter of raft-like microdomains in the mitochondrial membranes of halophytes, which differ in the type of salt tolerance: Salicornia perennans, Halocnemum strobilaceum, and Artemisia santonica. The packing density of the membrane lipids (lipid order) was assessed by measuring generalized polarization (GP) of the Laurdan fluorescence. In the mitochondrial membrane material of S. perennans, H. strobilaceum, and A. santonica, in the range of 15 and 25% of the sucrose density gradient, the GP distributions contain 4–6 components presumably related to the raft structures. Lipids isolated from ordered domains are enriched in sterols, cerebrosides, and saturated fatty acids; the quantitative content of raft-forming lipids depends on the salt tolerance strategy of halophytes.

The genus Rhodococcus includes polymorphic non-spore-forming gram-positive bacteria belonging to the class Actinobacteria. Together with Mycobacterium and Corynebacterium, Rhodococcus belongs to the Mycolata group. Due to their relatively high growth rate and ability to form biof ilms, Rhodococcus are a convenient model for studying the effect of biologically active compounds on pathogenic Mycolata. Colchicine was previously found to reduce biof ilm formation by P. carotovorum VKM B-1247 and R. qingshengii VKM Ac-2784D. To understand the mechanism of action of this alkaloid on the bacterial cell, we have studied the change in the fatty acid composition and microviscosity of the R. qingshengii VKM Ac-2784D membrane. Nystatin, which is known to reduce membrane microviscosity, is used as a positive control. It has been found that colchicine at concentrations of 0.01 and 0.03 g/l and nystatin (0.03 g/l) have no signif icant effect on the survival of R. qingshengii VKM Ac-2784D cultivated in a buffered saline solution with 0.5 % glucose (GBSS). However, colchicine (0.03 g/l) signif icantly inhibits biof ilm formation. Rhodococcus cells cultivated for 24 hours in GBSS with colchicine acquire a rounded shape. Colchicine at 0.01 g/l concentration increases C16:1(n-7), C17:0, C20:1(n-9) and C21:0 fatty acids. The microviscosity of the membrane of individual cells was distributed from the lowest to the highest values of the generalized laurdan f luorescence polarization index (GP), which indicates a variety of adaptive responses to this alkaloid. At a higher concentration of colchicine (0.03 g/l) in the membranes of R. qingshengii VKM Ac-2784D cells, the content of saturated fatty acids increases and the content of branched fatty acids decreases. This contributes to an increase in membrane microviscosity, which is conf irmed by the data on the GP f luorescence of laurdan. All of the above indicates that colchicine induces a rearrangement of the Rhodococcus cell membrane, probably in the direction of increasing its microviscosity. This may be one of the reasons for the negative effect of colchicine on the formation of R. qingshengii VKM Ac-2784D biof ilms.Род Rhodococcus объединяет полиморфные неспорообразующие грамположительные бактерии, относящиеся к классу Actinobacteria. Rhodococcus вместе с Mycobacterium и Corynebacterium входят в группу Mycolata. Благодаря относительно высокой скорости роста и способности к образованию биопленок, Rhodococcus являются удобной моделью для изучения действия биологически активных соединений на патогенные Mycolata. Ранее было показано, что колхицин угнетал образование биопленок у P. carotovorum ВКМ В-1247 и R. quingshengii ВКМ Ac-2784D. Целью настоящей работы было изучение действия колхицина на жирнокислотный состав и микровязкость мембран Rhodococcus qingshengii ВКМ Ac-2784D для понимания механизма действия этого алкалоида на бактериальную клетку. В качестве положительного контроля использовали нистатин, снижающий микровязкость мембран. Установлено, что колхицин в концентрациях 0.01 и 0.03 г/л и нистатин (0.03 г/л) не оказали существенного влияния на выживаемость R. qingshengii ВКМ Ac-2784D, культивируемого в забуференном физиологическом растворе глюкозы (ЗФРГ). Однако колхицин (0.03 г/л) значительно угнетал образование биопленки. Клетки Rhodococcus, культивируемые в течение суток в ЗФРГ с колхицином, приоб- ретали округлую форму. Колхицин в концентрации 0.01 г/л вызывал увеличение жирных кислот C16:1(n-7), С17:0, C20:1(n-9) и C21:0. Микровязкость мембраны отдельных клеток распределялась от максимально низких до максимально высоких значений показателя обобщенной поляризации флуоресценции лаурдана (GP), что свидетельствует о разнообразии адаптационных ответов на этот алкалоид. При более высокой концентрации колхицина (0.03 г/л) в мембранах клеток R. qingshengii ВКМ Ac-2784D увеличивалось содержание насыщен- ных жирных кислот и падало – разветвленных. Это способствовало увеличению микровязкости мембраны, что подтверждается данными по GP. Таким образом, колхицин индуцирует перестройку клеточной мембраны Rhodococcus, вероятно, в сторону увеличения ее микровязкости, что может быть одной из причин негативного действия колхицина на образование биопленок R. qingshengii ВКМ Ac-2784D.

The temperature dependences of luminescence in slip planes (111) of diamond plates containing nitrogen defects A and B1 upon excitation by a laser with a wavelength of 532 nm were investigated with the use of confocal scanning luminescence microscopy. The red glow of the diamond in the slip planes was dominated by the glow of the center with a zero phonon line (ZPL) of 656 nm at 290 K and the glow of the center with a zero phonon line of 701 nm at 80 K (i.e., spectra were different at different temperatures).

The results of the study of the parameters of the surface layer of a LiF crystal irradiated by Ag or Cu ion beam through a metal mask in the form of a grid with a period of 7 µm are presented. It was shown that a composite layer with a thickness of 3–5 µm is formed in the crystal in the form of a periodic structure containing F2 and F3+ color centers and (sub)nanometer metal particles. A diffraction pattern is observed on this structure upon irradiation with a laser beam.

The paper presents the results of luminescent studies of organs and tissues of endemic pelagic crustaceans during ontogenesis through the example of Epischura baikalensis. The spectral-kinetic characteristics of luminescence of E. baikalensis specimens have been measured. The results of laser confocal scanning luminescence microscopy studies with time resolution showed that the luminescence spectra of E. baikalensis is mainly defined by emission of Green Fluorescent Protein (GFP) and chlorophyll contained in cells of phytoplankton.

Color centers, found in lithium fluoride crystals grown in a reducing atmosphere and irradiated with a low dose of X-ray radiation, emit spectral luminescence band with maximum λmax = 800 nm and decay time constant of 26.5 ± 1 ns at room temperature. As the radiation dose increases, the concentration of these centers quickly saturates, while the concentrations of known intrinsic color centers continue to increase. This indicates the impurity nature of these color centers. The trajectories of the luminescence intensity and the decay time constants of single centers of this type were investigated. The luminescence is of flickering character. The temporal characteristics of the trajectories of luminescence intensity for different centers of the same type are different, while their decay time constants are the same. Similar pattern was revealed for the F2 color centers. These properties of single color centers in monocrystals are discussed.

The formation of thin layers of luminescent defects on the faces of planar lithium fluoride crystals located in the positive column and Faraday dark space of a glow gas discharge was studied by time-resolved confocal scanning luminescent microscopy and time-correlated single photon counting. The formation of aggregated color centers in the surface layers of crystals was established using the spectral and kinetic characteristics of luminescence appearing after irradiation. The role of gas discharge electrons, ions, and photons in the defect formation mechanism was considered. The defects were shown to be formed under the influence of vacuum ultraviolet (VUV) photons. The VUV radiation intensity distribution in the discharge gap was measured by the method of thermostimulated luminescence. The main source of this radiation was the anodic and cathodic voltage drop regions in a glow discharge.

Structural peculiarities and supramolecular organization of medicinally promising nanocomposites, synthesized from humic substances, which essentially differ depending on decomposition degree, have...

Proportions between oxidized and reduced glutathione forms were determined in vacuoles isolated from red beet (Beta vulgaris L.) taproots. The pool of vacuolar glutathione was compared with glutathione pools in isolated plastids and mitochondria. The ratio of glutathione forms was assessed by approved methods, such as fluorescence microscopy with the fluorescent probe monochlorobimane (MCB), high-performance liquid chromatography (HPLC), and spectrophotometry with 5,5′-dithiobis-2-nitrobenzoic acid (DTNB). The fluorescence microscopy revealed comparatively low concentrations of reduced glutathione (GSH) in vacuoles. The GSH content was 104 μM on average, which was lower than the GSH levels in mitochondria (448 μM) and plastids (379 μM). The content of reduced (GSH) and oxidized (GSSG) glutathione forms was quantified by means of HPLC and spectrophotometric assays with DTNB. The glutathione concentrations determined by HPLC in the vacuoles were 182 nmol GSH and 25 nmol GSSG per milligram protein. The respective concentrations of GSH and GSSG in the plastids were 112 and 6 nmol/mg protein and they were 228 and 10 nmol/mg protein in the mitochondria. The levels of GSH determined with DTNB were 1.5 times lower, whereas the amounts of GSSG were, by contrast, 1.5–2 times higher than in the HPLC assays. Although the glutathione redox ratios depended to some extent on the method used, the GSH/GSSG ratios were always lower for vacuoles than for plastids and mitochondria. In vacuoles, the pool of oxidized glutathione was higher than in other organelles.

The kinetic characteristics and temperature quenching of the luminescence of optical centers of silicon vacancies (SiVs) in diamond films grown in microwave plasma on substrates of aluminum nitride and synthetic diamond are investigated via laser excitation at a wavelength of 640 nm.

Natural diamonds are studied via confocal scanning fluorescent spectroscopy. Defects 523 and 794 nm have a number of similar features and are associated with one another. Features of their localization in the (111) planes of the individual growth pyramids testify to their postgrowth origin and are the result of plastic deformations. The structure of the defects presumably contains dislocations. The participation of other impurities in the structures of the defects is doubtful.

The role of glutathione in the plant vacuole is still being debated. In the present paper, the redox state of glutathione and the activity of glutathione S-transferase (GST, E 2.5.1.18) in the vacuole compared to those in leucoplast have been studied. Organelles were isolated from dormant red beet (Beta vulgaris L.) taproots. Two generally used approaches have been applied to quantitatively assess the content of glutathione. Initially, levels of glutathione were measured in isolated organelles after labeling with monochlorobimane (MCB) and imaging with the use of confocal laser scanning microscopy. However, there are factors limiting the specificity of this method, because of which the resulting concentrations of vacuolar GSH have been underestimated. Another approach used was HPLC, which allows to simultaneously quantify the reduced glutathione (GSH) and glutathione disulfide (GSSG). The concentration of the total glutathione (GSHt) and GSSG in vacuoles determined with the aid of HPLC-UV was higher in comparison to that in the leucoplasts. The reduction potential (Eh) for the glutathione couple in the vacuoles was more positive (−163 mV), than that in plastids (−282 mV). The relatively rapid increase in fluorescence in the isolated vacuoles and plastids during MCB-labeling has indicated to the contribution of GSTs, since the conjugation of GSH to bimane is catalysed by these enzymes. The GST activity in the vacuoles has been assessed to be quite high compared to that of leucoplasts. The number of isoforms of GSTs also differed markedly in vacuoles and plastids. Collectively, our findings suggest the idea that the glutathione accumulated by central vacuole seems to contribute to the redox processes and to the detoxification, which can take place in this compartment.

The microstructure of lithium fluoride thin films deposited on a glass substrate by thermal vacuum evaporation was investigated. An additional annealing of the films in air at temperatures of 400, 500, and 600°C resulted in an increase in the size of grains forming the film, as well as in the transformation of luminescence spectra of the initial and annealed samples before and after their X-ray irradiation used to generate in the films color centers that played the role of luminescent probes. It was found that an increase in the annealing temperature with an increase in the size of grains leads to a decrease in the intensity of the characteristic photoluminescence bands of color centers in lithium fluoride and to the appearance of new luminescence bands that are not characteristic of this material. Based on the results of the X-ray powder diffraction analysis, it was concluded that the increase in the grain size is caused by the change in the chemical composition of the films primarily due to the interaction of lithium fluoride with the substrate material.

The commented article contains numerous errors. The presentation of experimental data is slipshod and biased. They are not credible. The author had no reason to write about the scientific achievements outlined in the sections Abstract and Conclusion. One of the main conclusions of the work, that the author for the first time experimentally observed relation between orbital angular momentum of femtosecond laser radiation and induced by this radiation helicity of the tracks in crystals, has not been confirmed by direct check experiments. No orbital angular momentum of the exciting radiation nor the twisted tracks has been observed in the experiments. Other conclusions are also baseless.

A miniature low-voltage vacuum spark is an effective facility for creating composite layers in a dielectric matrix, including metal clusters, which have numerous optical applications. The results of studies of the optical characteristics of alkali-halide crystals (LiF and KCl) irradiated with beams of accelerated metal ions, which are emitted by a small-sized, low-voltage (2.5 kV) and low-energy (10 J) vacuum spark and a high-voltage (50 kV) pulsed ion implanter are presented. In both cases, composite layers of metal nanoparticles and/or molecular clusters are formed at submicrometer depth when irradiating these crystals. The low voltage implant method produces similar optical effects as seen in crystals processes at much higher energies. This result shows the possibility of creating a desktop metal ion implanter for various applications.

The luminescent characteristics of the layers formed in the LiF and KCl crystals as a result of irradiation of the crystals by ions emitted by a small-sized low-voltage vacuum spark with a voltage < 2 kV and a pulse duration of about 1 µs were studied. The photoluminescence technique showed that because of the irradiation, layers of sub-nanoscaled metal clusters are formed in crystals. Optical characteristics of these layers are close to those of layers formed owing to irradiating of the crystals by an ion beam with energy up to 150 keV emitted by a high-voltage ion implanter MEVVA. The results show that this "table-top" source of high-energy beams of metallic ions accelerated by a collective mechanism can be used to create modified micron scale layers in optical crystals for various applications.

The axial VUV radiation intensity distribution (< 130 nm) of an air glow discharge at pressure 50–530 Pa was obtained by the thermoluminescent method using the CaSO4·Mn thermoluminophor. The regions of maximum intensity of VUV radiation are the near-electrode regions in a wide range of pressures and voltages. The positive column of a glow discharge is also an area of intense VUV radiation at high-voltage. The formation of thin layer of luminescent defects on the faces of planar lithium fluoride crystals located in the positive column and Faraday dark space of a glow gas discharge was studied. By using a MicroTime 200 time resolution laser confocal scanning luminescence microscope (PicoQuant Gmbh) it was shown that the highest concentration of luminescent defects corresponds to the sides of the crystals that were irradiated near the electrodes.

Luminescence kinetics in the temperature range of 80–480 K and the red region of the spectrum is studied for Brazilian diamonds. Components with decay time constants of 23 and 83 ns are observed at room temperature after being excited by laser radiation with wavelengths of 375 and 532 nm, which differs considerably from the data published earlier for the luminescence kinetics of NV0- and NV–-centers.

The rate of intercombination transitions for single F2 color centers in a LiF crystal is estimated, in order of magnitude, as ΓTS ∼ 104 transitions/s using the results from the computer modeling of quantum trajectories of photoluminescence intensity of these centers. The lifetime of an F2 center in the first triplet state is found to be equal to 6.9 ± 0.7 s.

Results of investigation of peculiar properties related to the structure of plant cell vacuolar membranes are discussed. This investigation was conducted with the aid of confocal microscopy, which allowed us, in the process of scanning, to reveal nanotubes and vesicules in the preparations of isolated vacuoles. Such membrane nanotubes were observed both inside and outside the vacuoles, and, in the case of scanning intermittently at equal time intervals, transition of vesicules with a membrane nanotube. Furthermore, scanning of isolated vacuoles was conducted at various distances from the glass basement. Each time, in the upper part of an isolated vacuole lying on the basement, we observed a large segment of vacuolar membrane and registered the effect of highly intense fluorescing of some of the membrane segments. Distributions of laurdan fluorescence generalized polarization (GP) values for the vacuolar membrane on the whole and for the intensely fluorescing membrane segments have been obtained. It was discovered that the microviscosity of intensely fluorescing membrane segments essentially differs from the microviscosity of the rest part of the membrane.

Plates made of diamonds from the São Luiz province (Brazil) were investigated by confocal scanning luminescence microscopy. The samples have many macroinhomogeneities (cracks and inclusions), but there is a quasi-uniform distribution of luminescence centers in the bulk. At all investigated points of the crystals, the same group of centers was observed: N3, H4, 575, and a red band with a maximum at 690–700 nm. The visible nonuniformities in the distribution of luminescence over the area of the plates are determined by relatively small fluctuations in the ratio of the intensities of individual bands in the spectra. Nitrogen centers of different degrees of aggregation (H4, N3, and 575 nm, with four, three, and one nitrogen atom, respectively) coexist in these crystals. In the same zones of the samples, the distribution of blue luminescence (N3 centers) is diffuse (uniform), but the distribution of yellow-green luminescence is characterized by layering on (111). This might be a consequence of the tangential growth of octahedron faces or a result of plastic deformation of the crystals and dislocations along (111).

We present new data on the main and additional optically active defects in diamonds with cloudy microinclusions from the Mir kimberlite pipe. It has been found that reshaping might have occurred either in a closed system with nitrogen and hydrogen depletion or owing to new portions of a diamond-forming fluid/melt. The internal structure and the distribution of optically active defects suggest both continuous growth of such diamonds and a multistage scenario with a series of postcrystallizational transformations, including resorption, high-temperature annealing, and degradation of nickel-nitrogen complexes. © 2015, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

Notable within-crystal variability of mineralogical and geochemical properties of single natural diamonds are commonly attributed to changing chemistry of parental fluids, sources of carbon and redox conditions of diamond precipitation. A distinct type of compositional heterogeneity (mixed-habit structure) is well-known to occur in diamonds as well as in many other minerals due to purely “structural” reasons that are unequal crystal chemistry of crystallographically different faces and selective absorption and fractionation of impurities between adjacent growth pyramids. Based on the combined cathodoluminescence, Fourier-transformed infrared spectroscopy and photoluminescence spectroscopy, study of nine diamond crystals with different growth histories and external morphology, but all showing mixed-habit patterns at different growth stages, we show that mixed-diamonds may grow in closed system conditions or with a slowly decreasing growth rate from a media with a much lower impurity content than previously thought. Intracrystal nitrogen distribution seems to be a function of growth rate even in the cases of unusual impurity partitioning between growth sectors. Generally poor with IR-active hydrogen at moderate nitrogen aggregation parameters, studied diamonds likely resemble the low hydrogen content from the growth medium that, for cubic diamonds, was typically suggested hydrogen-rich and a crucial factor for growth of cubic and mixed-habit diamonds. We also show that mixed-habit diamond growth may occur not only in peridotitic suite but also in an extended field of geochemical affinities from high-Ni to low-Ni or maybe even Ni-free environments, such as pyroxenitic or eclogitic.

Under radiation from a barrier discharge, luminescent color centers are formed in a surface layer of lithium fluoride crystal served as a dielectric barrier. Analysis of the damping kinetics and luminescence spectra has revealed these centers to be F3+ and F2 centers. Structural defects are mainly formed via the photon-induced mechanism (i.e., defects are formed due to the generation of electron-hole pairs as a result of absorption of photons of barrier-discharge radiation). Barrier discharge in different gases can be successfully used to form thin layers containing luminescence centers on the surface of transparent insulators for various scientific and practical applications.

Line-by-line two-dimensional step small-scale scanning irradiation of a transparent cubic LiF crystal was carried out by intense linearly polarized femtosecond laser radiation in the multiple filamentation mode. As a result, isolated longitudinal extended tracks consisting of induced color centers were formed in the medium. It was found that no transverse periodicity associated with the scanning step is observed in the arrangement of tracks formed by laser filaments. This is because inhomogeneities that stimulate filamentation are not contained in the laser beam itself but are formed randomly when the medium interacts with the first laser pulses and are supported and amplified by subsequent pulses. The efficiency of color center formation in crystals at normal laser beam incidence on the cube face depends periodically on the azimuth angle θ between the electric vector and the cube edge on the face, with the period of π/2. It was found that azimuthal dependences for defect formation (maximum at θ = π/4) and for carrier photogeneration (maximum at θ = 0) are in the antiphase. Calculations showed that the processes of self-focusing and filamentation controlled by the components of the third-order nonlinear susceptibility tensor are most effective at the orientation where θ = π/4. The experiment showed that at such an orientation, the critical power and the length of self-focusing decrease, and therefore, the density of the number of filaments in the beam section increases and, as a result, the average concentration of the color centers created by laser filaments increases.

The spectral properties of a promising laser material, ternary molybdate Li3Ba2Gd3(MoO4)8:Nd3+, are studied (i.e., its optical absorption spectra, luminescence spectra, kinetic of luminescence decay, and temperature dependence of luminescence). Luminescence of the crystalline matrix is detected, and the temperature dependence of its intensity and reabsorption by neodymium are investigated.

The experiments conducted on tonoplast of Beta vulgaris L. roots were performed to identify detergent-resistant lipid-protein microdomains (DRMs, interpreted as lipid rafts).The presence of DRMs can be found when dynamic clustering of sphingolipids, sterols, saturated fatty acids is registered, and the insolubility of these microdomains in nonionic detergents at low temperatures is proven. The elucidation of tonoplast microdomains has been based on results obtained with the aid of high-speed centrifuging in the sucrose gradient. The experiments have shown that tonoplast microdomains are rich in sphingolipids, free sterols and saturated fatty acids (such a lipid content is also typical of lipid-protein microdomains of other membranes), while only few phospholipids are present in tonoplast microdomains. The presence of microdomains has been confirmed by fluorescence and confocal microscopy using filipin and Laurdan as fluorescent probes. The experiments with Laurdan have shown that tonoplast microdomains are characterized by a high order compared to characteristics of the rest of the tonoplast. Thus, the presence of detergent-resistant lipid-protein microdomains in the tonoplast has been demonstrated.

We offer the technique of differentiation of individual quantum systems based on the analysis of their time on the emitting and non-emitting state and on the frequency of transitions between them.

Using confocal fluorescence microscopy technique, we observed experimentally the luminescence of single F2 color centers in LiF crystal. It is disclosed that the fluorescence shows blinking behavior. It is shown that this phenomenon is caused by the F2 center reorientation occurring during the experiment. The ratio of luminescence intensities of differently oriented centers is assessed theoretically for two different experiment configurations. The calculated ratios are in fine agreement with experimental result.