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A series of pyridyl (pyridinium) substituted benzoxazoles were studied by steady state absorption, fluorescence spectroscopy, time-resolved fluorescence spectroscopy, fs pulse absorption and polarization spectroscopy, and quantum–chemical calculations. The spectral and kinetic parameters of the fluorophores in MeCN and EtOAc were obtained experimentally and were calculated by means of DFT and TDDFT methods. A scheme including four transient excited states was proposed for the interpretation of differential absorption kinetics of the charged fluorophores. Expressions describing the actual kinetics graphs, the decay associated spectra, and the species-associated spectra were derived. The charge shift step was found to be dependent on average solvation times. A charge shift followed by the formation of the twisted conformer was found for the excited 1-ethyl-3-(5-phenyloxazol-2-yl)pyridinium 4-methyl-1-benzenesulfonate in MeCN and EtOAc. Conformational analysis confirms a large amplitude motion of the meta-substituted ethylpyridinium group as an additional structural relaxation path producing an abnormally large fluorescence Stokes shift.

A series of Al2O3 nanoparticles with the sizes ranging from ~ 2 to 21 nm, according to XRD, HRTEM and BET, was obtained by vaporization of α-Al2O3 in flowing helium and argon at different pressures under the action of a cw CO2 laser. The particle size was changed by varying the composition of ambient gas (He, Ar) and its pressure in a vaporization chamber from 0.034 to 0.9 bar. The effect of the synthesis conditions on the properties of Al2O3 nanopowders is presented and discussed. Particles with the size smaller than 6–7 nm have a faceted shape, whereas the shape of larger particles is close to spherical. It was found that the resulting nanopowders consist of a mixture of transition aluminas, among which the γ-polymorph is dominant. Thermal analysis showed that for smaller nanoparticles the phase transition to α-Al2O3 occurs at a lower temperature. In nominally pure Al2O3 nanoparticles with different sizes, photoluminescence at RT and 80 K is determined by trace level concentrations (≤10–3 wt%) of uncontrolled impurities of 3d elements (Cr3+(Oh) and Fe3+(Td)), surface hydroxyl groups, and point defects represented mostly by F-type centers. The acquired experimental data indicate that manifestation of the size effect for Al2O3 nanoparticles has a boundary corresponding to 6–7 nm. Al2O3 nanoparticles with the dominant γ-Al2O3 structure obtained by the laser method can be promising in many chemical reactions, particularly as the supports of catalysts and sorbents, for which the high specific surface area is of special importance.

Abstract The review analyzes the potential of 31Р MAS NMR spectroscopy of adsorbed trisubstituted phosphines and phosphine oxides for the investigation of the acidic properties of molecular sieve catalysts. The main methodological approaches to identifying sites of different types are considered. The assignment of signals in the 31Р MAS NMR spectra of methyl-, ethyl-, n-butyl-, and phenyl-substituted phosphines and their oxides adsorbed on zeolites of different structural types and other molecular sieves to Lewis and Brønsted acid sites is reported, and the potential of 31Р MAS NMR spectroscopy as a tool for the determination of the strength of these sites and their amount is analyzed. It is shown that varying the size of the substituent allows assessment of the localization and accessibility of acid sites in zeolites.

The results of this study provide data on the luminescence and thermoluminescence properties of fluoride borate Ba12(BO3)6[BO3][LiF4] crystals co-doped with copper, rare earth elements, and strontium. The crystals were grown from high temperature solutions. This study revealed a considerable difference in decay time: about 60 ns for Cu+ photoluminescence at 412 nm in Ba12(BO3)6[BO3][LiF4]:Cu crystals after excitation at 263 nm, and about 1.8 ms for Eu3+ photoluminescence at 612 nm in Ba12(BO3)6[BO3][LiF4]:Cu,Eu crystals after excitation at 300, 325, and 395 nm. The absence of short-wavelength luminescence of Cu+ centers in photoluminescence spectra under 325 nm excitation in Ba12(BO3)6[BO3][LiF4]:Cu,Eu and Ba12(BO3)6[BO3][LiF4]:Cu,Eu,Tb,Ce crystals is associated with the nonradiative energy transfer from the excited electronic state of Cu+ ions to the energy levels of the rare earth elements. The thermoluminescence curves of these crystals lack a peak associated with capture centers. Co-doping with copper and strontium (Ba12(BO3)6[BO3][LiF4]:Cu,Sr, P42/mbc, a = 13.5174 (3) A, c = 14.9399 (3) A) has a noticeable effect on both photo- and thermoluminescence properties. This fosters the formation of deeper capture centers and promotes an increase in the temperature interval between thermoluminescence peaks, which is essential for the stable storage of dosimetric information. First-principles density functional theory investigation indicates that the presence of monovalent copper ions narrows the bandgap width compared to that of undoped Ba12(BO3)6[BO3][LiF4] crystals due to the transitions from the Cu-3d to Ba-5d levels. The presence of bivalent copper in the structure results in unfilled defect levels inside the bandgap. This contributes to the absorption in the visible range due to the electronic transitions from the O-2p to Cu-3d levels.

Lipofuscin granules accumulate in the retinal pigment epithelium (RPE) with age, especially in patients with visual diseases, including progressive age-related macular degeneration (AMD). Bisretinoids and their photooxidation and photodegradation products are major sources of lipofuscin granule fluorescence. The present study focused on examining the fluorescence decay characteristics of bisretinoid photooxidation and photodegradation products to evaluate the connection between fluorescence lifetime and spectral characteristics of target fluorophore groups. The primary objective of the study was to apply experimental spectral analysis results of lipofuscin granule fluorescence properties to interpretation of fluorescence lifetime imaging ophthalmoscopy data. Fluorescence analysis of the lipofuscin granule fluorophores in RPE collected from cadaver eyes was performed. The fluorescence lifetimes were measured by picosecond-resolved time correlated single photon counting technique. A global analytical method was applied to analyze data sets. The photooxidation and photodegradation products of bisretinoids exhibited a longer fluorescence lifetime (average value approximately 6 ns) and a shorter wavelength maximum (530–580 nm). Further, these products significantly contributed (more than 30%), to total fluorescence compared to the other fluorophores in lipofuscin granules. Thus, the contribution of oxidized lipofuscin bisretinoids to autofluorescence decay kinetics is an important characteristic for fluorescence lifetime imaging microscopy data analysis. The higher average fluorescence lifetime in AMD eyes was likely due to the higher abundance of oxidized bisretinoids compared with non-oxidized bisretinoids. Because higher level of oxidized bisretinoids is indicative of pathological processes in the retina and RPE, the present findings have the potential to improve fluorescence lifetime imaging approaches for early diagnosis of degenerative processes in the retina and RPE.

This paper presents the results of study of titanium–magnesium catalysts often used in polymerization processes, by photoluminescence spectroscopy (PL) in combination with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The interaction of dibutyl phthalate (DBP) with MgCl2was studied at DBPadded/Mg = 0–1 (mol/mol). The luminescence spectra with excitation at 278 nm and the excitation spectra for main emission bands were recorded. It was shown that DBP adsorbed on magnesium chloride, both in the form of donor–acceptor complexes (D+A–) and in the form of molecular complexes. At DBPadded/Mg +A–complexes occur predominantly; with an increase in DBPadded/Mg, the fraction of molecular complexes increases. Molecular complexes are destroyed during the treatment of the support by TiCl4. In this case, the structure of magnesium chloride is disordered and new coordination–unsaturated sites are formed. This work is a first attempt to apply PL spectroscopy in combination with DRIFTS spectroscopy to study titanium–magnesium Ziegler–Natta catalysts. The application of PL spectroscopy to such systems made it possible to detect interactions within and between donor molecules, which would be particularly challenging to achieve using other spectroscopic methods. Both spectroscopic methods provided crucial information about the existence of two types of complexes on the sample surface which is important for tuning the synthesis procedure of the titanium–magnesium catalysts for olefin polymerization.

A global analysis of the fluorescence decay kinetics of a chloroform extract of lipofuscin granules from the retinal pigment epithelium cells of human cadaver eyes is performed. The analysis makes it possible to reconstruct the individual fluorescence properties of four groups of fluorophores belonging to bisretinoids and the products of their photooxidation and photodegradation. The characteristic fluorescence lifetimes are correlated with the spectral characteristics of the indicated fluorophore groups using the averaged spectral and kinetic characteristics of the chloroform extract.

Photochemical properties of a new bis-cyanine dye have been investigated, including spectral kinetic characteristics of singlet and triplet excited states as well as affinity to BSA as a representative blood protein. The results obtained reveal, that the dye is a promising agent for imaging and fluorescent labeling of biomacromolecules.

Influence of small additives of copper, silver and tin on the angle of wetting and work of adhesion of monocrystals of chlorides of potassium and sodium is considered. The nature of interphase interaction of limit of the section monocrystals of chlorides of sodium and potassium with additives of the specified metals is revealed.

The effect of C60 fullerene aqueous colloid solution (C60FAS) on the intensity of long‑lasting (persisting for one hour) rotational movements in non‑anesthetized rats was investigated. For this purpose, an experimental hemiparkinsonic animal model was used in the study. Rotational movements in hemiparkinsonic animals were initiated by the intraperitoneal administration of the dopamine receptor agonist apomorphine. It was shown that a preliminary injection of C60FAS (a substance with powerful antioxidant properties) in hemiparkinsonic rats induced distinct changes in animal motor behavior. It was revealed that fullerene‑pretreated animals, in comparison with non‑pretreated or vehicle‑pretreated rats, rotated for 1 h at an approximately identical speed until the end of the experiment, whereas the rotation speed of control rats gradually decreased to 20-30% of the initial value. One can assume that the observed changes in the movement dynamics of the hemiparkinsonic rats after C60FAS pretreatment presumably can be induced by the influence of C60FAS on the dopaminergic system, although the isolated potentiation of the action of apomorphine C60FAS cannot be excluded. Nevertheless, earlier data on the action of C60FAS on muscle dynamics has suggested that C60FAS can activate a protective action of the antioxidant system in response to long‑lasting muscular activity and that the antioxidant system in turn may directly decrease fatigue‑relate d changes during long‑lasting muscular activity.

New derivatives of furodihydroquinoline (FDHQ) with substituents at the 5 position of the benzene ring have been synthesized, and their photophysical and photochemical properties have been studied. The triplet nature of short-lived states generated on photoexcitation of FDHQ has been shown with the use of pulse photolysis and triplet–triplet energy transfer to biscarbocyanine dye. Spectral and kinetic parameters of the triplet states for the synthesized FDHQ have been established. It has been shown that the FDHQ triplet state participates in the formation of the reactive oxygen species (ROS). Processes involving the FDHQ triplet state are important for PUVA-therapy and other processes of photochemotherapy.

Complexes of photosensitizers with blood proteins play an essential role in their delivery to the cell, as well as in the efficacy of photodynamic therapy. Biscarbocyanine dye non-covalently binds human serum albumin (HSA), the dissociation constant of the dye with albumin being Kd = (1.7 ± 0.1) × 10-5 M. According to time correlated single photon counting (TCSPC) fluorescence lifetime spectroscopy data, two types of complexes with lifetimes of 1.0 ns and 2.5 ns are formed between the dye and HSA. Confocal fluorescence microscopy has unambiguously shown the penetration of biscarbocyanine into endoplasmic reticulum, lysosomes, mitochondria and nuclei of the cells. The dye demonstrates photocytotoxicity towards the colon carcinoma HCT116 cells with IC50 = 0.3 μM. Hydrophobicity of the polymethine chain and the presence of two positive charges on the dye molecule contribute to the effective binding of the dye with HSA and the penetration into cells. These facts allow considering the biscarbocyanine dye as a promising agent for the photodynamic therapy of cancer.

A comprehensive study of optical and catalytic properties of highly dispersed single-phase η-, γ- and γ*-Al2O3 ([Cr3+] ∼ 10–4 wt.%) powders and the related model chromia-alumina catalysts with different chromium content ([Cr3+] = 0.25, 0.5 and 1 wt%) was carried out. The catalytic characteristics (product yield, conversion and selectivity) in isobutane dehydrogenation to isobutylene were measured for all the samples under consideration. The surface Cr3+S luminescence centers were detected by photoluminescence spectroscopy in all the samples. The content of Cr3+S centers in the samples was estimated before and after isobutane dehydrogenation. It was shown that the amount of surface Cr3+S centers correlates with isobutylene yields of the reaction. Among the studied samples, the maximum amount of Cr3+S luminescence centers was found for the model 1% Cr/γ-Al2O3 catalyst. This sample has the highest values of isobutane conversion and isobutylene yield. The comprehensive study of the Cr/Al2O3 systems made it possible to propose a method for predicting the catalytic activity of nanostructured materials using the photoluminescence detection of surface luminescence centers and their quantitative evaluation.

We present results of studies of formation mechanism of luminescence centers of the blue range in lithium fluoride crystals. We found that the centers under study are intrinsic defects of crystal lattice formed as a result of a radiation-thermal process in the temperature range much higher than room temperature. Experimental confirmation of simultaneous formation of these centers and F3+ centers, the increase in their concentration during thermal destruction of F3+ centers, and absence of the phonon structure characteristic of R2 centers give basis to attribute the considered centers to a stable configuration of intrinsic radiation defects constituting isomer of F3 center.

This paper is devoted to a determination of the 0% probability laser-induced damage threshold of the BaGa4Se7 and BaGa2GeSe6 nonlinear elements by the R-on-1 procedure. A Ho:YAG laser radiation at 2091 nm with pulse duration 13-17 ns and varied pulse repetition rate, 2 kHz, 5 kHz and 10 kHz, was used for testing.

The fundamental aspects related to the mechanisms of action of C60 fullerene nanoparticles on the level of the central nervous system in different experimental conditions are still unclear. Electrophysiological investigation and immunohistochemical techniques of c-fos expression were combined to determine which neural elements within the lumbar segments and in the central nucleus of the amygdala (CeA) are activated under skeletal muscle fatigue development with prior application of C60 fullerenes (dissolved in dimethyl sulfoxide and in distilled water, FDS). After high-frequency electrical stimulation of the triceps surae muscle, the main fatigue-related increases in the c-Fos expression level were registered ipsilaterally within lamina 1 and 5 of the lumbar segments and within the contralateral capsular part of the CeA. C60 fullerene pretreatment in animals with subsequent electrical stimulation induced a distinct (2–4 times) decrease in the level of Fos immunoreactivity in the observed structures in comparison with only fatigue-induced rats. It can be supposed that FDS, as antioxidant compound, can decrease the concentration of free radicals in fatigued tissue and reduce the transmission intensity of nociceptive information from muscles to the spinal cord and amygdala, thereby changing the level of c-Fos expression within the lumbar segments and CeA.

A method for the synthesis of a series of symmetric and asymmetric conformationally fixed tricarbocyanines was developed based on benzоindolenine containing ethyl phosphonate and diethyl phosphonate groups in the linker at the quaternary nitrogen atom of the indolenine fragment. The polymethine chain meso position was modified by nucleophilic substitution of chlorine with O- and N-nucleophiles. Their absorption and fluorescence spectra were recorded, the possibility of further use of phosphonate-substituted tricarbocyanines as biomarkers was demonstrated. The dark cytotoxicity of synthesized compounds was studied, the possibility of their accumulation in HCT116, MCF7 cancer cells was shown.

We investigated neuronal activation of the rat intermediolateral (IML) nucleus of the thoracolumbar spinal cord, initiated by Achilles tendon vibration, after intramuscular (m. triceps surae) administration of 7‑nitroindazole (7‑NI) or L‑arginine (LA). The spindle afferent response to vibratory stimuli induced a distinct bilateral increase in the activation of c‑Fos immunoreactivity in the spinal neurons in three groups of rats (tendon‑vibrated, tendon‑vibrated + 7‑NI and tendon‑vibrated + LA). The T5/T13 segments in tendon‑vibrated +7‑NI animals showed the highest increase of Fos‑immunoreactive neurons. This increase was two times higher than that in tendon only‑vibrated control rats and endon‑vibrated + LA animals. The highest mean number of labelled neurons were observed in the IML nucleus and in layers 4 and 7 of the T5-L3 segments in tendon‑vibrated and tendon‑vibrated + 7‑NI animals, and in the IML nucleus and layer 4 in tendon‑vibrated + LA rats. The highest mean number of activated neurons was found ipsilaterally in the IML nucleus of the T5/T13 segment. These results indicate that decreased nitric oxide release after injection of 7‑NI was accompanied by a potentiation of the early c‑fos gene expression induced by muscle proprioceptive activity within the thoracolumbar region of the rat spinal cord. Thus, enhanced c‑Fos immunoreactivity in the IML nucleus indicated that the sympathetic nervous system can exert a direct influence on the muscle spindles.

Oxygen vacancies represented by F and F2 centers were detected in faceted Al2O3 nanoparticles with the size less than 10 nm by a photoluminescence method. Al2O3 nanoparticles with such intrinsic defects were synthesized by evaporation of α-Al2O3 in flowing helium using a continuous wave CO2 laser. The XRD analysis showed that the crystal structure of Al2O3 nanoparticles is represented mostly by the low-temperature γ- and/or η-Al2O3 phases. The luminescence maxima of F and F2 centers in the Al2O3 nanoparticles were found to be 3.07 and 2.47 eV. These values are close to the luminescence maxima of F and F2 centers in bulk α-Al2O3.

New hetarylazo dyes with dihydroquinoline and tetrazole moieties with different substituents at the tetrazole cycle were synthesized and their spectral properties and thermal Z‒E isomerization were investigated in toluene, MeCN and DMSO. The substitution of H with the CH3 group at the tetrazole fragment results in the disappearance of concentration dependence of the absorption spectra observed for the dyes with unsubstituted tetrazole in MeCN and DMSO. The time-resolved measurements in MeCN and DMSO show the existence of several forms of Z-isomers with lifetimes on μs‒ms time scale for the dyes with unsubstituted tetrazole and a single Z-isomer for the dyes with the CH3 group at tetrazole. The position of the CH3 group at the tetrazole fragment affects the lifetime of the Z-isomer, which changes from ms to seconds and minutes on passing from 2-methyl- to 1-methyl-tetrazole. The structural features of the dihydroquinolylazotetrazole dyes and complex formation with solvents are discussed.

Polyethylene m-Y2O3:Eu3+ composites (PECs) containing 0.32, 0.77, and 1.79 wt% of well-dispersed sphere-like m-Y2O3:Eu3+ nanoparticles were obtained by in situ polymerization in the presence of a titanium-magnesium catalyst (TMC). TMC was synthesized by sequential deposition of organic magnesium and TiCl4 on m-Y2O3:Eu3+ that had been previously dehydroxylated at 650 °C. Detailed photoluminescence properties of the obtained composites as a function of m-Y2O3:Eu3+ content were investigated in combination with UV–Vis and IR spectroscopy data. It was shown that Eu3+ ions in monoclinic Y2O3 lattice are responsible for the high red emission of the composites. The effect of the РЕС host on the luminescence properties of m-Y2O3:Eu3+ was revealed. The obtained chromaticity coordinates with improved red color (0.653, 0.347) and high absolute luminescence quantum yield up to 23% make РЕСs potential promising materials for luminescent applications.

The photoinduced electron transfer from ascorbic acid as a donor to the dication of the bis-carbocyanine dye (BCD2+) in its triplet state was studied by flash photolysis. The differential absorption spectrum of the BCD•+ radical cation was recorded and its decay kinetics was measured. Possible mechanisms for the deactivation of this radical were proposed.

Phototransformation of a cyanine dye with two chromophores (biscyanine dye, BCD) subject to visible light in phosphate buffer was studied using optical absorption and fluorescence spectroscopic techniques. The effects of the dye concentration and molecular oxygen were demonstrated. The monoexponencial dependence of optical absorption of the BCD solution on the irradiation time was observed. The increase of the characteristic phototransformation time with the dye concentration is explained in terms of the dye aggregation. The explanation is confirmed by experiments in the presence of SDS micelles, where the concentration effect is absent, since at binding with SDS micelles BCD does not aggregate. The dye phototransformation rate increase in the presence of oxygen is explained in terms of singlet oxygen formation due to energy transfer from the dye excited triplet state to molecular oxygen. Singlet oxygen was detected, and its quantum yield was determined by an indirect chemical method. The effect of singlet oxygen on the BCD phototransformation was confirmed by reduction of its phototransformation rate in the presence of 2,5-dimethylfuran, a known singlet oxygen water soluble quencher. Singlet oxygen may destroy the π-conjugation of the BCD chromophores. A possible structure of the dye photoproduct is proposed based on the similarity of its spectral characteristics and those of monochromophoric cyanine dye and confirmed by quantum chemical modelling.

The joint effect of the impurity profile of a material and the thermal conditions of the formation of color centers upon irradiation in crystalline optical media is investigated. Special attention is given to additional gamma re-irradiation in thermally effective ranges for active centers, which establishes conditions for their preferential production.

Electron-microscopic and electron-probe x-ray spectral studies of nitride fuel microstructure in thin sections and fractures of pellets in correlation with the xenon distribution were conducted in order to obtain data on the particulars of porosity formation and mechanisms of swelling of nitride fuel during low-temperature irradiation. The results attest indications of restructuring of nitride fuel irradiated to burn up 5.5% h.a. at temperature below 880°C. The formation of some grain structure in the restructuring process, accompanied by emission of gaseous fission products from the fuel matrix into pores, affects the swelling rate of uranium-plutonium nitride fuel.

The monograph is devoted to molecular mechanics simulations of biologically important polymers like proteins and nucleic acids. It is shown that the algorithms based on the classical laws of motion of Newton, with high-quality parameterization and sufficient computing resources is able to correctly reproduce and predict the structure and dynamics of macromolecules in aqueous solution. Summarized the development path of biopolymers molecular mechanics, its theoretical basis, current status and prospects for further progress. It may be useful to researchers specializing in molecular Biophysics and molecular biology, as well as students of senior courses of higher educational institutions, studying the biophysical and related areas of training.

Davydov, A.S., Teoriya moleculyarnykh eksitonov (Theory of Molecular Excitons), Moscow: Nauka, 1968. Borisevich, Yu.E., Dokl. Akad. Nauk. SSSR, 1978, vol. 241, p. 743. Borisevich, Yu.E., Kuzmin, V.A., Mikhailenko, F.A., and Dyadyusha, G.G., Dokl. Akad. Nauk. SSSR, 1976, vol. 228, p. 375. Borisevich, Yu.E., Kuzmin, V.A., Dyadyusha, G.G., and Mikhailenko, F.A., Dokl. Akad. Nauk. SSSR, 1976, vol. 229, p. 131. Schaberle, F.A., Kuzmin, V.A., and Borissevitch, I.E., Biochim. Biophys. Acta, 2003, vol. 1621, part 2, p. 183. Murakami, L.S., Ferreira, L.P., Santos, J.S., Silva, R.S., Nomizo, A., Kuzmin V.A., and Borissevitch, I.E., Biochim. Biophys. Acta, 2015, vol. 1850, p. 1150. Jiao, L., Song, F., Cui, J., and Peng, X., Chem. Comm., 2018, vol. 54, p. 9198. Kuzmin, V.A., Tatikolov, A.S., and Borisevich, Y.E., Chem. Phys. Lett., 1978, vol. 53, p. 52. Kostyukov, A.A., Nekipelova, T.D., Borissevitch, I.E., and Kuzmin, V.A., High. Energy Chem., 2019, vol. 53, p. 87. Kostyukov, A.A., Nekipelova, T.D., Radchenko, A.S., Golovina, G.V., Klimovich, O.N., Shtil, A.A., Codograto, D.C.K., Goncalves, P.J., Pavanelli, A.L.S., Ferreira, L.P., Amado, A.M., Borissevitch, I.E., and Kuzmin, V.A., High. Energy Chem., 2017, vol. 51, p. 148. Radchenko, A.S., Kostyukov, A.A., Mestergazi, M.G., Borissevitch, I.E., and Kuzmin. V.A., 17th International Congress on Photobiology, Barcelona, Spain, August 25−30,2019, Book of Abstracts, p. 759. Download references Spectral measurements were carried out on the spectrophotometric complex of the Shared Facilities of Institute of Biochemical Physics, Russian Academy of Sciences. The study was supported by the Russian Scientific Foundation, agreement no. 18-13-00463. Correspondence to A. E. Egorov. Translated by T. Nekipelova Reprints and Permissions Egorov, A.E., Kostyukov, A.A., Nekipelova, T.D. et al. Photoreduction of the Triplet State of Biscarbocyanine Dye. High Energy Chem 54, 142–144 (2020). https://doi.org/10.1134/S001814392002006X Download citation Received: 26 September 2019 Revised: 26 September 2019 Accepted: 23 October 2019 Published: 25 March 2020 Issue Date: March 2020 DOI: https://doi.org/10.1134/S001814392002006X

Europium doped Gd2O3 sphere-like nanoparticles with dm = 9.3 ± 3.5 nm were synthesized by cw CO2 laser vaporization technique in a flowing mixture of argon and oxygen. According to XRD data, the Eu:Gd2O3 nanoparticles crystallize in the monoclinic symmetry class (C2/m space group). High-resolution luminescence spectroscopy study showed that the ultra-narrow 5D0 → 7F0 transition of Eu3+ demonstrates only two peaks corresponding to two inequivalent Cs positions of Eu3+ ion in monoclinic Gd2O3 lattice that is explained by the peculiarities of local environment of Eu3+ ion at these sites. The hypersensitive transition 5D0 → 7F2 dominates in the spectrum and is expanded to the red part of the spectrum in comparison with cubic Eu:Gd2O3 due to intense transitions terminating at higher-lying components of the crystal-field-split 7F2 state. In the luminescence spectrum, an additional weak band with the maximum at 407 nm corresponding to the electronic transitions 4f65 d1(7FJ) → 4f7(8S7/2) of Eu2+ was detected. The obtained values of chromaticity coordinates and absolute quantum yield are (0.644; 0.325) and ca. 1%, respectively. The phase transformations have been investigated using differential scanning calorimetry and thermogravimetry (50–1400 °C). After annealing in air at 700 °C, the monoclinic symmetry class of the Eu:Gd2O3 nanoparticles is preserved and the particle size increases to dm = 17.8 ± 6.1 nm. After annealing, the chromaticity coordinates (0.659; 0.334) and absolute quantum yield (ca. 4%) can be obtained using red phosphor based on monoclinic Gd2O3:Eu3+. The lifetime of the excited 5D0 state of Eu3+ in the annealed nanoparticles is longer than that in the as-synthesized nanoparticles, due to the suppression of nonradiative decay after annealing.

A new approach to functionalize porphyrinoids was developed based on the Vilsmeier formylation followed by the azine formation and a new class of the compounds namely azines of porphyrinoids was obtained. Variously substituted azine porphyrins, chlorins and their dyads were synthesized, and their structural and electronic parameters were studied with X-ray diffraction analysis, electronic absorption and emission spectra, electrochemistry and DFT calculations. Azine represents a very peculiar bridge with an unclear conjugation ability affecting optical properties of chromophores. This work was aimed to reveal azine properties and the influence of the azine bridge on the chromophores linked. The results of investigation allowed to conclude that azine bridge can partly be regarded as a conjugation switch with a high threshold level of switching, where limited conjugation in the ground state can be greatly increased at higher energy states of the azine molecule.

New tricarbocyanine dyes with phosphonate groups (2, 3) were synthesized and their binding constants to bovine serum albumin (BSA) were determined. The binding constants of the synthesized tricarbocyanines and cardiogreen (1) (K b ~ 105 M–1) are similar, indicating an insignificant contribution of the Coulomb interaction to the complex formation, which is determined by the polymethine chain interaction with BSA. The fluorescence lifetimes attest to the formation of two types of complexes: the lifetime of the dye complex with BSA with a major contribution (~80%) is 740–800 ps, and a lifetime of ~210 ps corresponds to the complex of dye aggregates with BSA.

Tetrapyrrolic macrocycles are suitable for a variety of chemical modifications aimed at new agents for binary antitumor treatment and diagnosis. Previously we have reported that the conjugation of one single carborane cage to the chlorin e6 macrocycle, a modification designed for tumor sensitization in photodynamic (PDT) and boron neutron capture (BNCT) therapies, yielded the derivative with a higher photosensitizing potency in the models of transplanted rodent tumors. This effect was mechanistically linked to the localization of the carboranylchlorin in membrane organelles due to the carborane moiety. Further exploring the potential of modified tetrapyrrolic compounds as photoradiosensitizers we synthesized the chlorin derivative carrying four closo-carborane cages (44 boron atoms) and 16 fluorine atoms at the periphery of the macrocycle (fluorinated tetracarboranylchlorin, compound 1). For comparison of the properties of 1, its fluorine free congener (tetracarboranylchlorin 6) was obtained. The water soluble 1 and 6 accumulated preferentially in cells selected for resistance to chemotherapeutic drugs (multidrug resistance and cisplatin resistance) than in the parental non-selected counterparts. Compounds 1 and 6 showed a negligible dark cytotoxicity. In contrast, a monochromatic light illumination of cells loaded with low micromolar concentrations of 1 or 6 triggered rapid (within minutes) photonecrosis as determined by the entry of propidium iodide or SYTOX dyes into the parental as well as into resistant cells. In vivo 1 or 6 (up to 80 mg/kg i.p.) caused no general toxicity in Balb/c or C57BL6 mice. Illumination with a monochromatic light of B16 melanoma transplants in mice injected with 5 mg/kg 1 or 6 caused a significant shrinkage of tumor foci, with no re-growth in 77.8% animals by day 21 post PDT. BNCT on C6 rat glioma xenografts in Balb/c nu/nu mice injected i.p. with 5 mg/kg 1 led to a decrease of tumor foci and cure of animals by day 29 whereas the radiosensitizing potency of 6 was less pronounced. This difference was attributable to a limited intratumoral accumulation of 6. Altogether, an extensive modification of the chlorin macrocycle periphery with polyfluorines and polycarboranes yielded potent and well tolerable compounds for PDT and BNCT.

Laser vaporized xCr/Al2O3 nanopowders with the particle size of ca. 15 nm were studied by XRF, EDX, HRTEM, XRD, DD, BET, TGA, UV–Vis DRS, Raman and PL spectroscopy methods as a catalytic system in dehydrogenation of isobutane. The nanopowders were found to contain not only the Cr6+ ions located on the surface of nanoparticles, but also two different types of Cr3+ sites as components of the γ-Al2O3 solid solution. One type consists of the bulk Cr3+b sites in a strong crystal field. Another type is represented by the Cr3+s sites residing near the surface of xCr/Al2O3 nanoparticles. Such sites are in a weak crystal field. It was shown that catalytic activity of the nanostructured xCr/Al2O3 system is provided by the high content of surface Cr3+s sites. The results obtained make it possible to propose the nanopowders obtained by laser synthesis as a promising catalytic system that can be used in the development of highly active catalysts for dehydrogenation of alkanes with the decreased chromium content.

In this work experimental research results of silicon deep plasma etching features during 3D-TSV structure producing in inductively coupled plasma are presented. Silicon etching operational parameters influence (inductor RF power, working gas consumption) on process technological characteristics (Si etching rate, selectivity and etching profile) is investigated. Wherein passivation stage’s operational parameters were not changed and were constant. It is shown that microroughness in the form of microneedles and column structures can be formed on the bottom of formed structures at low RF power values; full stop of Si etching process can be also possible. It has been revealed that during polymerization stage fluorocarbon film’s deposition rate increase is observed on structure’s inclined surface in comparison with film’s deposition rate on vertical surfaces. At the same time fluorocarbon film’s deposition rate on the bottom of trench is higher than in inclined surface of the structure. Silicon surface after deep plasma etching process is studied. Fluorocarbon film’s adhesion to silicon and silicon oxide ability is researched. It is demonstrated that adhesion on test samples has small values or missing.

A series of novel meso- triazoloporphyrin-carborane conjugates was prepared in good yields via the copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of Zn(II) or Pd(II) 5,10,15,20-tetrakis[4-(2-propargyloxy)-2,3,5,6-tetrafluorophenyl]porphyrin or Zn(II) 5,10,15,20-tetra(p-propargyloxyphenyl)porphyrin with 1-azidomethyl-o-carborane in CH2Cl2. Zinc metalloporphyrins were demetallated under acidic conditions to afford the corresponding free-base triazolo-carborane porphyrins in excellent yields. All new compounds were characterized by MS, NMR and UV–vis spectroscopy and their photophysical properties were studied.

Europium doped Y2O3spherical nanoparticles with the diameter ~10 nmobtained via cw laser vaporization are shown to crystallize in monoclinic symmetry class (C2/m space group). The size of nanoparticles established via HRTEM coincides with coherent scattering region established by XRD. Luminescence spectrum in the vicinity of ultranarrow transition demonstrates three peaks consistent with three inequivalent positions of Eu3+ ion in monoclinic Y2O3 lattice. Hypersensitive transition dominates in the spectrum, admitting the lack of inversion symmetry at Cs sites occupied by Eu3+. The spectrum of hypersensitive transition is expanded to the red part of spectrum due intense transitions terminating at higher-lying components of crystal-field-split 7F2 energy level. Obtaining chromaticity coordinates (0.669, 0.331)and absolute quantum yield (~21%) is possible using red phosphor based on monoclinic Y2O3:Eu3+.

The high sensitivity of modern techniques for lifetime detection opens new significant opportunities for investigation of various processes in the biological media. Here, we report on the novel sub-class of cyanine dyes. We examined the effect of electronic coupling on the optical properties of the complex of the dye with the human serum albumin. TCSPC measurements of fluorescence decay provided evidence that the studied dye generates more than two kinds of complexes with albumin. It was established that the effect of “frozen structure” in complex changes the rate of photoisomerization way of the dye’s excited state degradation. Furthermore, by means of molecular docking, the experimentally proposed mechanism of complex formation and the existence of several binding sites were confirmed.

A set of AT-specific fluorescent dimeric bisbenzimidazoles DBPA(n) with linkers of different lengths bound to DNA in the minor groove were synthesized and their genetic, virological, and biochemical studies were performed. The DBPA(n) were shown to be effective inhibitors of the histon-like protein H-NS, a regulator of the DNA transcription factor, as well as of the Aliivibrio logei Quorum Sensing regulatory system in E. coli cells. Their antiviral activity was tested in model cell lines infected with herpes simplex virus type I. Also, it was found that DBPA(n) could inhibit catalytic activities of HIV-1 integrase at low micromolar concentrations. All of the dimeric bisbenzimidazoles DBPA(n) manifested fluorescent properties, were well soluble in water, nontoxic up to concentrations of 200 µM, and could penetrate into nuclei followed by binding to DNA.

The aim of this study is to detect the effects of C60 fullerenes, which possess pronounced antioxidant properties, in comparison with the actions of the known exogenous antioxidants N-acetylcysteine (NAC) and β-Alanine in terms of exercise tolerance and contractile property changes of the m. triceps surae (TS) during development of the muscle fatigue in rats. The electrical stimulation of the TS muscle during four 30 min series in control rats led to total reduction of the muscle contraction force. Furthermore, the effects of prior intraperitoneal (i.p.) or oral C60FAS application and preliminary i.p. injection of NAC or β-Alanine on muscle contraction force under fatigue development conditions is studied. In contrast to control rats, animals with C60FAS, NAC, or β-Alanine administration could maintain a constant level of muscle effort over five stimulation series. The accumulation of secondary products and changes in antioxidant levels in the muscle tissues were also determined after the fatigue tests. The increased levels of lactic acid, thiobarbituric acid reactive substances and H2O2 after stimulation were statistically significant with respect to intact muscles. In the working muscle, there was a significant (p < 0.05) increase in the activity of endogenous antioxidants: reduced glutathione, catalase, glutathione peroxidase, and superoxide dismutase. Treated animal groups showed a decrease in endogenous antioxidant activity relative to the fatigue-induced animals (P < 0.05). Oral C60FAS administration clearly demonstrated an action on skeletal muscle fatigue development similar to the effects of i.p. injections of the exogenous antioxidants NAC or β-Alanine. This creates opportunities to oral use of C60FAS as a potential therapeutic agent. Due to the membranotropic activity of C60 fullerenes, non-toxic C60FAS has a more pronounced effect on the prooxidant-antioxidant homeostasis of muscle tissues in rats.

Spectroscopic features of the local structure of high purity (with the content of impurities −3 wt.%) spinel-like γ- and γ ∗ -Al 2 O 3 phases differing in the unit cell parameters were studied. Samples of these phases were synthesized from crystalline boehmite and nanodispersed pseudoboehmite, respectively. For each of the phases, photoluminescence of transition metal ions and oxygen vacancies – F- and F 2 -centers – was detected, and Raman scattering spectra were recorded. The photoluminescence study of γ ∗ -Al 2 O 3 revealed octahedrally coordinated ions Mn 4+ . Values of the crystal field strength and Racah parameters for Mn 4+ ions in γ ∗ -Al 2 O 3 were determined. Manifestation of PL of Mn 4+ ions in γ ∗ -Al 2 O 3 and its absence in γ-Al 2 O 3 can serve as the indicator for distinguishing between these phases. It was found that γ- and γ ∗ -Al 2 O 3 samples have individual Raman spectra. The revealed spectroscopic features in the local structure of γ- and γ ∗ -Al 2 O 3 phases confirm the differences between these spinel-like structures.

Laser evaporation of an Al2O3 target by a continuous wave CO2 laser was used to obtain nanostructured Al2O3 condensates with a mean crystallite size of 6 nm, one nominally pure and another doped with chromium at a concentration of 0.2 wt%. Photoluminescence of Cr3+ was observed in all the samples of the Al2O3 condensate. In all the Al2O3 condensates the α-Al2O3 phase, undetectable by XRD and HRTEM, was revealed by Cr3+ probing. Photoluminescence studies with the use of Cr3+ as a probe also revealed the θ- and (γ + δ)-crystal phases of Al2O3; this finding was supported by XRD and HRTEM data.

Research is devoted to studying properties of YAG:Ce luminophores prepared by reverse heterophase coprecipitation followed by annealing. Luminophore specimens are synthesized using fluxes of different composition and with different grain size. Property indices are determined for the specimens obtained by electron-probe analysis methods for phase chemical composition, x-ray phase analysis, and spectrofluorimetry.

The thermal properties and phase compositions of zeolite from the Vanginskoe and Kulikovskoe deposits in Amur Oblast were studied by means of x-ray diffraction. The temperature interval for the existence of the zeolite structure in these deposits was determined. A scheme for obtaining zeolite concentrated was tested.

The effects of C60FAS (50 and 500 μg/kg) supplementation, in a normal physiological state and after restraint stress exposure, on prooxidant/antioxidant balance in rat tissues were explored and compared with the effects of the known exogenous antioxidant N-acetylcysteine. Oxidative stress biomarkers (ROS, O2⋅−, H2O2, and lipid peroxidation) and indices of antioxidant status (MnSOD, catalase, GPx, GST,γ-GCL, GR activities, and GSH level) were measured in the brain and the heart. In addition, protein expression of Nrf2 in the nuclear and cytosol fractions as well as the protein level of antiradical enzyme MnSOD and GSH-related enzymesγ-GCLC, GPx, and GSTP as downstream targets of Nrf2 was evaluated by western blot analysis. Under a stress condition, C60FAS attenuates ROS generation and O2⋅−and H2O2releases and thus decreases lipid peroxidation as well as increases rat tissue antioxidant capacity. We have shown that C60FAS supplementation has dose-dependent and tissue-specific effects. C60FAS strengthened the antiradical defense through the upregulation of MnSOD in brain cells and maintained MnSOD protein content at the control level in the myocardium. Moreover, C60FAS enhanced the GSH level and the activity/protein expression of GSH-related enzymes. Correlation of these changes with Nrf2 protein content suggests that under stress exposure, along with other mechanisms, the Nrf2/ARE-antioxidant pathway may be involved in regulation of glutathione homeostasis. In our study, in anin vivomodel, when C60FAS (50 and 500 μg/kg) was applied alone, no significant changes in Nrf2 protein expression as well as in activity/protein levels of MnSOD and GSH-related enzymes in both tissues types were observed. All these facts allow us to assume that in thein vivomodel, C60FAS affects on the brain and heart endogenous antioxidative statuses only during the oxidative stress condition.