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The primary stages of the Exiguobacterium sibiricum rhodopsin (ESR) photocycle were investigated by femtosecond absorption laser spectroscopy in the spectral range of 400-900 nm with a time resolution of 25 fs. The dynamics of the ESR photoreaction were compared with the reactions of bacteriorhodopsin (bR) in purple membranes (bRPM) and in recombinant form (bRrec). The primary intermediates of the ESR photocycle were similar to intermediates I, J, and K in bacteriorhodopsin photoconversion. The CONTIN program was applied to analyze the characteristic times of the observed processes and to clarify the reaction scheme. A similar photoreaction pattern was observed for all studied retinal proteins, including two consecutive dynamic Stokes shift phases lasting ∼0.05 and ∼0.15 ps. The excited state decays through a femtosecond reactive pathway, leading to retinal isomerization and formation of product J, and a picosecond nonreactive pathway that leads only to the initial state. Retinal photoisomerization in ESR takes 0.69 ps, compared with 0.48 ps in bRPM and 0.74 ps in bRrec. The nonreactive excited state decay takes 5 ps in ESR and ∼3 ps in bR. We discuss the similarity of the primary reactions of ESR and other retinal proteins.

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.

The objective of this study was screening of ommochromes from the compound eyes of insects and comparison of their antioxidant properties. Ommochromes were isolated in preparative quantities from insects of five different families: Stratiomyidae, Sphingidae, Blaberidae, Acrididae, and Tenebrionidae. The yield of ommochromes (dry pigment weight) was 0.9-5.4% of tissue wet weight depending on the insect species. Isolated pigments were analyzed by high-performance liquid chromatography and represented a mixture of several ommochromes of the ommatin series. The isolated ommochromes displayed a pronounced fluorescence with the emission maxima at 435-450 nm and 520-535 nm; furthermore, the emission intensity increased significantly upon ommochrome oxidation with hydrogen peroxide. The ommochromes produced a stable EPR signal consisting of a singlet line with g = 2.0045-2.0048, width of 1.20-1.27 mT, and high concentration of paramagnetic centers (> 1017 spin/g dry weight). All the investigated ommochromes demonstrated high antiradical activity measured from the degree of chemiluminescence quenching in a model system containing luminol, hemoglobin, and hydrogen peroxide. The ommochromes strongly inhibited peroxidation of the photoreceptor cell outer segments induced by visible light in the presence of lipofuscin granules from the human retinal pigment epithelium, as well as suppressed iron/ascorbate-mediated lipid peroxidation. The obtained results are important for understanding the biological functions of ommochromes in invertebrates and identifying invertebrate species that could be used as efficient sources of ommochromes for pharmacological preparations to prevent and treat pathologies associated with the oxidative stress development.

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.

The article provides an overview of the frequency of distribution of pyometra in cats. Risk factors, clinical manifestations and clinical forms of the disease are analyzed. Current methods of pyometra diagnostics and clinical and laboratory criteria for early detection of signs of sepsis (systemic inflammatory response) in cats with pyometra are considered. The methods of pyometra therapy are analyzed. It was emphasized that the most effective and safest method of treating any form of pyometra is a total ovariohisterectomy in combination with broad-spectrum antibiotics. Encouraging results in the treatment of an open uncomplicated form of pyometers in cats were obtained using, along with antibiotics, preparations based on PgF2alfa and aglepristone.

The oxidation resistance of detonation spraying coatings of the FeAlCr/Al2O3 powder fabricated by mechanically assisted self-propagating high-temperature synthesis using aluminothermic reactions of oxide reduction is investigated. The powder has a sufficiently homogeneous composite structure consisting of chromium-alloyed ordered B2-FeAl and fine inclusions of α-Cr2O3 and α-Al2O3. The detonation coatings sprayed on stainless steel substrates have a typical layered structure without cracks and spalling. The coating thickness is 250–300 μm, and microhardness is in a range of 5.9–6.1 GPa. Coatings of the synthesized powder mainly inherit its structure and phase composition, although certain aluminum and chromium oxidation occurs when spraying. The features of the cyclic and isothermal oxidation of coatings in air in a temperature range of 900–1000°C are studied. It is established that the oxidation resistance of detonation coatings of the synthesized powder after oxidation in air for 48 h at 950°C is close that of coatings formed from the FeAl‒FexAly powder with an aluminum content of 45 wt %. At the same time, the linear thermal expansion coefficient (LTEC) of FeAlCr/Al2O3 coatings is closer to the LTEC of the base material, while their creep resistance is higher when compared the latter due to the presence of fine refractory oxide inclusions. It is assumed that α-Cr, Cr2O3, and numerous fine alumina inclusions present in the synthesized powder (and which form when spraying) accelerate the protective film, formation suppressing hematite nucleation and growth at early oxidation stages at temperatures up to 950°C.

We have studied dark-adaptation at three levels in the eyes of the crustacean Mysis relicta over 2–3 weeks after exposing initially dark-adapted animals to strong white light: regeneration of 11-cis retinal through the retinoid cycle (by HPLC), restoration of native rhodopsin in photoreceptor membranes (by MSP), and recovery of eye photosensitivity (by ERG). We compare two model populations (“Sea”, Sp, and “Lake”, Lp) inhabiting, respectively, a low light and an extremely dark environment. 11-cis retinal reached 60–70% of the pre-exposure levels after 2 weeks in darkness in both populations. The only significant Lp/Sp difference in the retinoid cycle was that Lp had much higher levels of retinol, both basal and light-released. In Sp, rhodopsin restoration and eye photoresponse recovery parallelled 11-cis retinal regeneration. In Lp, however, even after 3 weeks only ca. 25% of the rhabdoms studied had incorporated new rhodopsin, and eye photosensitivity showed only incipient recovery from severe depression. The absorbance spectra of the majority of the Lp rhabdoms stayed constant around 490–500 nm, consistent with metarhodopsin II dominance. We conclude that sensitivity recovery of Sp eyes was rate-limited by the regeneration of 11-cis retinal, whilst that of Lp eyes was limited by inertia in photoreceptor membrane turnover.

Structure and properties of detonation gun sprayed (DS) coatings from the synthesized FeAlSi/Al2O3 powder have been investigated. The powder was manufactured through a mechanically assisted self-propagating high-temperature synthesis route. A small addition of nanosized SiO2 particles to the reaction mixture for the synthesis of FeAl-FeAl2 eutectoid refines the thickness of B2-FeAl lamellar grains in the synthesized powder. Silicon arisen from the aluminothermic reduction of SiO2 during the synthesis is preferentially located in the B2-phase. High-quality coatings with porosity less than 1 vol% and nanocomposite structure have been obtained from the synthesized powder using a computer-aided ‘Perun-S’ detonation gun complex. Phase composition of the coatings includes B2-FeAl, hercinite FeAl2O4, FeAl2, A2-Fe-based solid-solution, Al2O3, and probably complex Fe2.95Si0.05O4 oxide. It is formation of nanocomposite structure with the mean crystallite size of main components in the range of ≈9–15 nm that seems to be responsible for the lower microhardness of the coatings from the FeAlSi/Al2O3 powder than that of the basic Fe-Al eutectoid composition. As-sprayed coatings from the synthesized FeAlSi/Al2O3 powder demonstrate good room and elevated temperature erosion behavior. Oxide dominated erosion with mixed brittle-ductile wear behavior is thought to occur in the coatings at 550 °C. The proposed powder modification is found to be beneficial for the oxidation resistance of DS coatings in air at 950 °C. Promoting of alumina formation during oxidation and the corresponding decline in Fe2O3 content in the oxide scale are considered as the main reasons for the slower oxidation kinetics of the FeAlSi/Al2O3 coatings as compared with those of the basic Fe-Al eutectoid composition.

Hydroxyapatite was synthesized in conditions of mechanoacoustic treatment of an aqueous reaction mixture consisting of ammonium hydrogen phosphate and calcium nitrate using a commercially available rotary pulsation apparatus. Mechanoacoustic treatment of the reaction mixture was found to lead to the formation of nanosized hydroxyapatite particles with a predominant mean diameter of about 20 nm. Purification of technical hydroxyapatite to remove traces of ammonium nitrate by thermal processing at 350°C is proposed. The crystalline phase of hydroxyapatite was found not to be dominant in the structure. The porosity of hydroxyapatite amounted to about 75% with a mean pore diameter of 2.8 × 103 nm. Thermal processing of hydroxyapatite in aqueous medium was found to yield a paste-like form. Hydroxyapatite paste had no cytotoxicity and did not prevent cell adhesion, though it almost completely inhibited cell spreading.

The presence of carotenoids in the vitreous body, retina, lens, retinal pigment epithelium together with choroid (hereinafter RPE), and ciliary body and iris together with choroidal stroma (hereinafter CBI) was studied throughout the second trimester of prenatal development of the human eye. It has been found that the vitreous body, retina, and RPE contain lutein and its oxidized forms. Zeaxanthin was not found in the tissues studied. The presence of lutein in the vitreous body is transient and no longer detected after 28 weeks of gestation. Lutein was not detected in the lens and CBI, but its oxidized forms were found. The presence of carotenoids in different tissues of the eye in the course of normal eye development and the antioxidant role of carotenoids are discussed.

The behavior of detonation and plasma coatings in conditions of dry friction against titanium alloy OT-4 and stainless steel 07Kh16N6 has been studied. The detonation coatings show significantly better tribological properties than the plasma coatings. This is probably due to the presence of aluminum and titanium nitrides possessing high wear resistance in the detonation coatings. Oxidation of the plasma and detonation coatings at a temperature of 900°C in air has been examined. The detonation and plasma coatings exhibit greater oxidation resistance than uncoated titanium alloy VT-16.

The supramolecular organization of the visual pigment rhodopsin in the photoreceptor membrane remains contentious. Specifically, whether this G protein-coupled receptor functions as a monomer or dimer remains unknown, as does the presence or absence of ordered packing of rhodopsin molecules in the photoreceptor membrane. Completely opposite opinions have been expressed on both issues. Herein, using small-angle neutron and X-ray scattering approaches, we performed a comparative analysis of the structural characteristics of the photoreceptor membrane samples in buffer, both in the outer segment of photoreceptor cells, and in the free photoreceptor disks. The average distance between the centers of two neighboring rhodopsin molecules was found to be ~5.8 nm in both cases. The results indicate an unusually high packing density of rhodopsin molecules in the photoreceptor membrane, but molecules appear to be randomly distributed in the membrane without any regular ordering.

Photochemical reaction dynamics of the primary events in recombinant bacteriorhodopsin (bRrec) was studied by femtosecond laser absorption spectroscopy with 25-fs time resolution. bRrec was produced in an Escherichia coli expression system. Since bRrec was prepared in a DMPC–CHAPS micelle system in the monomeric form, its comparison with trimeric and monomeric forms of the native bacteriorhodopsin (bRtrim and bRmon, respectively) was carried out. We found that bRrec intermediate I (excited state of bR) was formed in the range of 100 fs, as in the case of bRtrim and bRmon. Further processes, namely the decay of the excited state I and the formation of intermediates J and K of bRrec, occurred more slowly compared to bRtrim, but similarly to bRmon. The lifetime of intermediate I, judging from the signal of ΔA ESA(470-480 nm), was 0.68 ps (78%) and 4.4 ps (22%) for bRrec, 0.52 ps (73%) and 1.7 ps (27%) for bRmon, and 0.45 ps (90%) and 1.75 ps (10%) for bRtrim. The formation time of intermediate K, judging from the signal of ΔA GSA(625-635 nm), was 13.5 ps for bRrec, 9.8 ps for bRmon, and 4.3 ps for bRtrim. In addition, there was a decrease in the photoreaction efficiency of bRrec and bRmon as seen by a decrease in absorbance in the differential spectrum of the intermediate K by ~14%. Since photochemical properties of bRrec are similar to those of the monomeric form of the native protein, bRrec and its mutants can be considered as a basis for further studies of the mechanism of bacteriorhodopsin functioning.

Integral parameters of bacterial lipopolysaccharide concentration and antiendotoxin immunity activity were determined in the blood serum of subjects with two extreme variants of eating disorders: obesity and anorexia nervosa (in its clinical model, long-term starvation). The results of the study showed that obese patients had initially higher endotoxin concentrations (2.41 ± 0.11 vs 1.13 ± 0.05 EU/mL in the control), which significantly decreased as a result taking a course of orlistat or after starvation (for no longer than 20 days) (to 1.34 ± 0.04 and 1.01 ± 0.09 EU/mL, respectively). The decrease in the endotoxin serum level was associated with an increase in the concentration of high-density lipoproteins (HDLs) and a decrease in the concentration of low-density lipoproteins (LDLs). This allowed us to assume that the complex of the latter with the endotoxin is the LDL fraction that may function as a depot of the hydrophobic form of the lipopolysaccharide molecule in the bloodstream. Long-term starvation (starting from day 20) led to the appearance of symptoms characteristic of septic states, which was preceded by a twofold increase in the concentration of the endotoxin and antibodies against the enterobacterial common antigen and subsequent increase in the level of anti-glycolipid antibodies (from 133.2 ± 2.6 to 355.6 ± 15.0 optical density arbitrary units) starting from day 25–27 of starvation, which is characteristic for the initial phase of the systemic inflammatory response syndrome.

Reactions of copper(II) carboxylates with dibenzyl ether (DBE) gave binuclear complexes of the formula Cu2(μ-OOCR)4(DBE)2 (R = But, Ph, and CF3). The complexes were characterized by X-ray diffraction. The axial positions in the lantern-type dimer are occupied by the coordinated DBE molecules. The complexes seem to be analogs of intermediate catalysts for the oxidation of DBE with atmospheric oxygen in the presence of transition metal complexes. When stored in air, the complex Cu2(μ-OOCPh)4(DBE)2 underwent oxidation into Cu2(μ-OOCPh)4(HOOCPh)2, which was characterized by X-ray diffraction. The geometry of its framework is similar; the structure is stabilized by intramolecular H bonds between the axially oriented benzoic acid molecules and the adjacent bridging benzoate anions.

A room-temperature reaction of cupric acetate dihydrate with 3,5-bis(trifluoromethyl)pyrazole ((CF3)2pzH) in chloroform in the presence of triethylamine gave a complex of the formula [Cu2(μ-(CF3)2pz)2(μ-OH2)(OC(Me)OHNEt3)(OH2)(HCCl3)(OOCMe)(μ-OOCMe)]2 (2). Heating of this complex at 180°C in dibenzyl ether (DBE) in air yielded the tetranuclear pyrazolate-benzoate cluster Cu4(μ4-OH)(μ-(CF3)2pz)4(μ-OOCPh)2(μ-OH)2(OH2)(Et3NH)[O(CH2Ph)2]2. It was suggested that such complexes can be intermediates in the liquid-phase oxidation of DBE with atmospheric oxygen in the presence of copper complexes containing pyrazolate bridges.

Deprotonation reactions of pyrazole and its analogs by aqueous copper acetate in benzene at room temperature in the presence of triethylamine were studied. Unlike 3,5-dimethylpyrazole, more acidic pyrazole, 5-methyl-3-trifluoromethylpyrazole, and 3,5-bis(trifluoromethyl)pyrazoles are deprotonated to give pyrazolate bridges. The structural features of the obtained compounds are discussed based on X-ray diffraction data.

The content of carotenoids and retinoids was compared in the eyes of two Finnish populations of the opossum shrimp, Mysis relicta, which have been reproductively isolated for at least 9000 years: one from the deep, dark, Lake Paajarvi, the other from the Baltic Sea (Pojoviken Bay). The eyes of the lake population (LP) are highly susceptible to light damage, while those of the sea population (SP) are more resistant. Carotenoids are known to act as antioxidants protecting cells against free radicals and reactive oxygen species; retinoids, on the contrary, may be phototoxic in certain conditions. Analyzed by spectrophotometry and HPLC, the carotenoid content was broadly similar in the eyes of the two populations as regards both total amount and relative proportions of more than 20 components. Noteworthy differences were found in only three of the major components, among these astaxanthin, which was two times higher in SP compared with LP. The most interesting finding was the 1.6-fold higher content ...

The reaction between Co(Hdmpz)2(OOCPh)2 and cobalt acetate hydrate leads to the deprotonation of coordinated pyrazole and formation of pyrazolate-bridged Co2(μ-dmpz)2(Hdmpz)2(OOCPh)2 binuclear complex. The structure of the complex was determined by X-ray crystallography.

Dissolution of benzoic or pivalic acid in excess triethylamine followed by crystallization was found to yield single crystals of 1: 1 and 1: 2 complexes, respectively. X-ray crystallography have shown that the complex with benzoic acid is an (Et3NH)+(OOCPh)− ion pair, in which the proton is transfered from the acid to the base (N⋯O 2.629(2) A), and the complex with pivalic acid contains, in addition to the ion pair (N⋯O 2.649 A), the homoconjugate anion (ButCOO)(H)(OOCBut)− (O⋯O 2.521 A).

The dissolution of aqueous copper acetate in tetrahydrofuran gives the Cu2(μ-OOCMe)4(thf)2 complex (1), and its reaction with triethylamine in the presence of acetic acid yields “[Cu2(μ-OOCMe)4[μ-OOCMe(HNEt3)]”n polymer (2). Complexes 1 and 2 react with 3,5-dimethylpyrazole to form Cu(Hdmpz)2(OOCMe)2 (3) and Cu2(μ-OOCMe)4(Hdmpz)2 (4), respectively. The structures of complexes 1–4 and that of solvate 4 × 0.5C6H6 (5) are determined by X-ray diffraction.

Visible light-induced changes in fluorescence characteristics of lipofuscin granules (LG) isolated from retinal pigment epithelium of human cadaver eyes are compared with the analogous age-related changes and correlated with the content and photooxidation of LG main fluorophore, A2E. We used HPLC to examine changes of LG fluorophore composition with donor age, as well as before and after visible-light irradiation (the latter HPLC tests were also done with synthetic A2E). Visible light induces oxidation of LG fluorophores. As a result, their fluorescence characteristics change: the emission spectrum is blue-shifted by 25–40 nm. The observed age-dependent changes in the relative content of LG fluorophores and their oxidized derivatives were qualitatively similar with those caused by irradiation. To improve the accuracy of a new noninvasive diagnostic method, fundus autofluorescence imaging, it is important to know the ratio of nonoxidized and oxidized fluorophore derivatives depending on age and eye pathology.

We discovered that reactions of [Pd(OOCMe)2] n and Pd3(μ-OOCMe) with 3,5-dimethylpyrazole (Hdmpz) yield mononuclear complex [Pd(Hdmpz)4](OOCMe)2, in which acetate anions can exchange for pivalate or benzoate anions in reactions with proper acids. The specifics of intramolecular hydrogen bonding in the complexes prepared are discussed as dependent on the nature of the carboxylate anion using X-ray crystallography data.

Carotenoids were found for the first time in the vitreous body of human eye during the fetal period from week 15 until week 28. Their maximum content was timed to week 16–22. No carotenoids were found the vitreous body of 31-week fetuses, as well as adult humans, which corresponds to the published data. It was shown using HPLC that chromatographic characteristics of these carotenoids correspond to those of lutein and zeaxanthin, characteristic pigments of the retinal yellow macula.

The possibility of replacing the electrolyte based on imported ethylene carbonate with a domestic SO2-containing electrolyte based on propylene carbonate was considered for the example of operation of the negative electrode of a lithium-ion battery.

Using synchrotron-based in situ X-ray diffraction, the structural changes of LiCoO 2 , LiCo 0.5 Ni 0.5 O 2 , and LiNi 0.65 Co 0.25 Mg 0.05 Ti 0.05 O 2 cathode materials during charge in the voltage range of 3.5 to 5.2 V have been studied. When a LiCoO 2 cathode was charged above 4.5 V, a new intermediate phase O1a was observed, before the terminal phase O1 was formed around 4.8 V. In the X-ray diffraction spectra for LiCo 0.5 Ni 0.5 O 2 and LiNi 0.65 Co 0.25 Mg 0.05 Ti 0.05 O 2 cathode materials, Bragg peaks representing the O1 structure were also observed. The amounts of O1 structure formed at the end of charge (5.2 V for LiNi 0.65 Co 0.25 Mg 0.05 Ti 0.05 O 2 and 5.0 V for LiCo 0.5 Ni 0.5 O 2 ) were increased with increasing Co content.

Individual sensitivity to nickel compounds was studied in workers employed in nickel industry. The mutagen sensitivity was inferred from the number of sister chromatid exchanges (SCEs), which was used to characterize the structural alterations of the chromosomes in workers' lymphocytes before and after administration of retinol for a month. The SCE number decreased after retinol administration in nine out of eleven workers.

The reactions of [Pd(Hdmpz)4](OOCR)2 (R = Me, Bu t , Ph, Hdmpz = 3,5-dimethylpyrazole) with the heterometallic acetate Pd(μ-OOCMe)4Co(NCMe) gives pyrazolate-bridged dimers Pd2(μ-dmpz)2(Hdmpz)2(OOCR)2 (R = Me, Bu t , Ph), which were characterized by X-ray diffraction.

The ability of deuteromycetes of the genera Penicillium, Aspergillus, and Botrytis to retain collagenolytic activity was studied after both 2 and 10 years of storage on a Czapek medium under a layer of mineral oil at 4°C, as well as in silica gel granules at 20 and −60°C. The enzymatic activity of several species, including Botrytis terrestris, Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum, was retained under both conditions of storage. Aspergillus repens retained enzymatic activity only if stored under a layer of mineral oil. The viability of conidia and the collagenolytic activity of Botrytis terrestris, P. janthinellum, P. chrysogenum, and Penicillium citrinum, maintained on silica gel for 10 years, depended on the storage temperature. The viability of the test strains improved after storage on a silica gel at −60°C. A strain of Aspergillus repens lost its ability to dissolve collagen at various storage tempeatures on the silica gel. The index of lysis for three strains of Penicillium deuteromycetes (Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum) increased after a 10-year storage on silica gel at −60°C.