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The effect of treatment of polyacrylonitrile (PAN) fibers with nanoparticles of silk fibroin on the dyeability of fibers with acid dyes was investigated. As a result of the attachment of oligomeric protein fragments containing amino groups to the fibers the affinity of the anionic dye to the fibers increases. Modification of PAN fibers with oligomers of fibroin obtained from silk waste can be recommended for the dyeing of mixed materials and articles.

Non-woven needle-punched material with silver nanoparticles was obtained from the waste of natural silk cocooning process. Silver nanoparticles were synthesized by chemical reduction from an ammonia solution of silver nitrate. It is shown that the treatment of silk material with a solution of 1-butyl-3-methylimidazolium chloride affects the amorphous-crystalline state of the fiber, its sorption properties and the resistance of silver nanoparticles on the fiber to wet treatments.

An aqueous solution of fibroin nanoparticles, obtained as a result of thermal hydrolysis of the waste products from silk fibers, was used to modify polyacrylonitrile fibers. According to light scattering data, the fibroin nanoparticles in aqueous solution had hydrodynamic radii of 75-95 nm. It was established by chromato-mass spectroscopy that the nanoparticles contain oligomeric fragments of a polypeptide chain and the products from their condensation with the formation of cyclic diketopiperazines. In the IR spectra of the fibers after treatment with fibroin nanoparticles there are bands associated with the absorption of N–H groups. The intermolecular interaction between the carbonyls of PAN in the fiber and the active groups of the fibroin oligomers can be judged from the shift of the C=O bands of itaconic acid into the low-frequency region and from the increase in the absorption of the ester groups. Strong attachment of the fibroin nanoparticles to the PAN fiber is favored by chemical reaction between the carboxyls of the itaconic acid in the structure of the fiber and the amino groups of the fibroin fragments. The increase of the relative nitrogen content after modification of the PAN fibers with fibroin nanoparticles is confirmed by the results of elemental analysis.

Silk fibers served as a matrix for the reduction of nanoparticles from a silver salt solution. A mathematical model describing the dependence of the total content of reduced silver on a fiber Y on the input parameters X1, X2, X3, X4 (silver concentration in the treatment solution, concentration of reducing agent, temperature and duration of the reduction process, respectively) is constructed. A chemically substantiated nonlinear regression model and a two-layer perceptron are proposed, which make it possible to obtain mathematical expressions for the dependence of the silver content on silk fibers on the input parameters. Both models adequately reflect the experimental data – the error of the regression model is 0.16, the error of the two-layer perceptron is 0.14.

The model of multiphase media analyzes the effectiveness of describing thermal expansion and shrinkage of unidirectional polymer composites at their uniform heating by linear law. It is shown that the nature of change in thermal deformation as a function of the composite temperature is similar for an unreinforced matrix, and the maximum absolute value of chemical shrinkage is slightly lower than that of a matrix. The calculated deformations describing thermal expansion are compared with experimental deformations obtained in the process of thermal-oxidative destruction.

Impairments of sleep and waking in diseases such as Parkinson’s disease, dementia, Lewy body dementia, and Alzheimer’s disease are encountered in a large proportion of patients. Sleep has many functions, supporting the normal operation of the brain, and impairments to sleep may be among the factors promoting the development of neurodegenerative diseases. Impairments to sleep and waking may exacerbate the course of the neurodegenerative process and lead to increases in symptoms, including cognitive impairments. This article presents a detailed analysis of the literature linking sleep and waking impairments and cognitive impairments in neurodegenerative diseases. The phenomenology and methods of correcting sleep and waking impairments in these diseases are discussed.

Objectives. To study the N-acetylaspartate (NAA) content in the plasma of elderly patients with depression during treatment with antidepressants combined with Actovegin. Materials and methods. Nineteen patients – seven men, 12 women, age 70.5 ± 5.8 years – were treated in hospital conditions. Patients underwent clinical psychiatric evaluation using a series of psychometric scales, along with computerized tomography (CT) and biochemical assay of NAA. Patients received antidepressants (venlafaxine and fluvoxamine at therapeutic doses) and Actovegin for 28 days and were investigated before and after treatment (day 28). Results and conclusions. Decreases in blood NAA were found in pretreatment patients as compared with healthy subjects, with increases after treatment, which corresponded to a significant improvement in patients’ status both clinically and on psychometric scales. Heterogeneity was found in the cohort of patients in relation to the nature of changes in contents (increases or decreases) of NAA, which was not linked with treatment efficacy but correlated with the burden of comorbid somatic diseases, especially vascular, and some CT features (leukoaraiosis). The authors emphasize the preliminary nature of the results.

The possibilities of obtaining porous permeable cermet SHS-materials with catalytic properties are studied. The charge composition consists of powders of alloy steel scale, ilmenite concentrate, aluminum or chromium oxides, the basis of material forming the backbone of cermet (Al2O3) and reduced iron, and also added metaloxides. The material obtained is intended for the catalytic purification of diesel engine exhaust gases, particularly from nitrous oxide, carbon monoxide and soot.

A model of primary photosynthetic reactions in the thylakoid membrane was developed and its validity was tested by simulating three types of experimental kinetic curves: (1) the light-induced chlorophyll a fluorescence rise (OJIP transients) reflecting the stepwise transition of the photosynthetic electron transport chain from the oxidized to the fully reduced state; (2) the dark relaxation of the flash-induced fluorescence yield attributed to the QA− oxidation kinetics in PSII; and (3) the light-induced absorbance changes near 820 or 705 nm assigned to the redox transitions of P700 in PSI. A model was implemented by using a rule-based kinetic Monte-Carlo method and verified by simulating experimental curves under different treatments including photosynthetic inhibitors, heat stress, anaerobic conditions, and very high light intensity.

An optimum charge composition is developed for preparing porous permeable cermet SHS-materials with prescribed operating properties for cleaning exhaust gases of industrial installations and internal combustion engines. Physicomechanical properties of the materials obtained are determined with a different content of charge components and the range of vibration frequency is established suitable for material operation as filters. It is shown that addition of 0.5 – 1.5 wt.% of alloying elements to a charge increases SHS-material mechanical strength and shock resistance.

Objective. To carry out a comparative assessment of the efficacy and safety of monotherapy with a new-generation antidepressant (venlafaxin, agomelatine, or fluvoxamine) and complex antidepressant therapy using one of these antidepressants in combination with acetyl-L-carnitine (ALC, Carnicetin) for the treatment of depression in elderly patients in a gerontology psychiatric out-patients clinic. Materials and methods. Two groups of patients (aged 60–79 years) with mild or moderate depression, comparable in terms of the main demographic and clinical characteristics, received antidepressant mono- or complex (antidepressant and ALC) therapy for eight weeks. Results. The use of complex therapy including the neuroprotector Carnicetin, which has neurotrophic and energotropic mechanisms of action, was found to provide a faster-onset therapeutic response and a stronger effect than antidepressant monotherapy, which was supported by a significant reduction in depressive disorders, including measures of the severity of anxiety, along with improvements in the patients’ cognitive functioning. Use of complex therapy was accompanied by a decrease in the frequency of adverse events. Conclusions. The results obtained here allow inclusion of Carnicetin into the complex antidepressant treatment to be recommended for use in gerontology psychiatric out-patient clinics.

During pregnancy, several complications have been associated with hyperhomocysteinemia (HHcy) and elevated homocysteine (Hcy) levels have been shown to play a role in the etiology of preeclampsia, placental abruption, intrauterine growth retardation, and neural tube defects and associated with the neurological consequences. In the present work, we investigated the effects of chronic maternal HHcy on the development and neurobehavioral maturation of the offspring. We analyzed classical parameters of development such as body weight, eyelid opening, ear unfolding, incisor eruption, and the appearance of hair, and subjected the pups to various tests that reflected the neurobehavioral maturation extending from 4th to 20th postnatal days (righting reflex, negative geotaxis, cliff avoidance, head shake, acoustic startle reflex, free-fall righting, cliff avoidance caused by visual stimulus, olfactory discrimination). We have shown that newborn animals were characterized by lower body weight and higher mortality. Besides, the delay in neurobehavioral maturation of the pups from the Hcy group was observed. The obtained results indicate that early developmental impairments of brain maturation induced by prenatal HHcy may underlie long-term deficits in the learning and memory behaviors.

Neurophysiological correlates of treatment efficacy in late-onset depression were identified by analyzing EEG spectral parameters, the peak latencies of the “late” components of cognitive auditory evoked potentials, and sensorimotor reaction times during antidepressant treatment in two groups of older patients (53‐72 years) with long-lasting psychogenic depressive reactions (ICD-10 F43.21) and endogenous depression (ICD-10 F33.1 and F31.3). The initial severity of depression was associated with EEG signs of decreases in the functional status of the anterior parts of the left hemisphere and increased activation of the right hemisphere (particularly the temporal areas). Improvements in patients’ mental status in response to antidepressant medication were accompanied by decreases in the peak latencies of the “late” components (P2, N2, and P3) of cognitive auditory evoked potentials and acceleration of sensorimotor reactions, and were linked with improvements in EEG measures of the functional status of the posterior areas of the cerebral cortex and increases in inhibitory processes in the right hemisphere (particularly its frontal-central-temporal areas). These data are consistent with views of the systems nature of impairments to brain activity in depression and the predominant involvement of the left hemisphere in regulating positive emotions and of the right hemisphere in regulating negative emotions, including the pathogenesis of depression.

The composition and content of exchange cations on the surface and in the interior volume of different clays are studied. It is found that the atomic (ionic) composition of the surface of clay particles influences the adsorption and rheological properties of a suspension upon introduction of electrolytes. The possible exchange reactions between the molecules of the electrolyte and the ions of a clay particle are determined.

IR absorption spectra of mesogenic crystals based on substituted aryl propargyl ethers of phenols (APEP) are calculated and analyzed using the LADY program. Force constants and interatomic potentials of atoms not covalently bonded adequately describe experimental IR spectra. The corresponding bands in the absorption spectra are interpreted. The influence of the substitution type on the force field of separate molecules in APEP crystals is clarified.

Data on the synthesis of 19 new azo-pyrazoles which are promising for use as dyes for polycaproamide are reported. Their structure and the properties of the polycaproamide fabrics dyed with them were investigated and a correlation was established between the structure of the azo-pyrazoles and the color fastness of the fabrics in laundering, wet and dry rubbing, and exposure to light and molds.

The paper presents results of lithological-mineralogical, Mossbauer, and isotope-geochronological study of globular phyllosilicates (glauconite and illite) from the Lower Cambrian Virbalis Formation in western Lithuania. K-Ar dates of these minerals (382 and 374 Ma) do not correspond to stratigraphic positions of the studied samples and indicate the loss of radiogenic 40Ar, probably, in Middle Devonian. Simulation of cation distribution in the mineral structure and comparison of the obtained data with Mossbauer spectral characteristics suggest that loss of 40Ar was caused by the structural rearrangement of globular phyllosilicates during the postdiagenetic substitution of Fe2+, Mg2+, and Fe3+ by Al3+, with the subsequent ordering of cation distribution in octahedral layers. These processes were presumably related to the same Caledonian tectonic events that were responsible for metasomatic dolomitization of Lower Paleozoic rocks in adjacent areas of the Baltic region at the terminal Silurian-Devonian. Diffraction analysis showed that globules consist of two micaceous phases with different Fe contents (illite and glauconite). Two alternative models are considered to explain the formation of two-phase globules: (1) disequilibrium conditions of diagenetic mineral formation; (2) transformation of glauconite into illite. Although the available data are insufficient to make an unambiguous choice between these models, the second mechanism seems to be more preferable.

For several surfactants, free energies of adsorption Δ(G a 0 )γ are calculated relative to a symmetrically chosen standard state. It is shown that they characterize the strength of organic molecule-metal bond. The effect of these surfactants on active corrosion of lead in acetic acid solution, as well as correlation between the inhibition coefficient and the free energy of adsorption Δ(G a 0 )γ, is studied by measuring the polarization resistance. The corrosion rate of lead in acetic acid solution with and without adding surfactants was studied gravimetrically. In this case, the corrosion rate was virtually independent of surfactant additives and their chemical nature; this is associated with the oxidation of lead surface.

We studied the role of ryanodine receptors in the effects of hydrogen sulfide on transmitter release from frog motor nerve ending. Sodium hydrosulfide (300 μM), a donor of hydrogen sulfide, reversibly increased the frequency of miniature endplate current without changes in its amplitude-time parameters. These effects were associated with reversible increase in endplate current amplitude, which was abolished by activation of ryanodine receptors of intracellular Ca(2+)stores with caffeine (3 mM) and ryanodine (0.5 μM). Under conditions of ryanodine receptors blockade with ryanodine (10 μM), sodium hydrosulfide had no effect on induced transmitter release, but its effects remained unchanged during ryanodine receptors blockade with dantrolene (25 μM). We concluded that an enhanced acetylcholine release induced by hydrogen sulfide is related to an increase of intracellular Ca(2+)concentration due to activation of ryanodine receptors for intracellular Ca(2+)-pool.

A method for estimating thermodynamic parameters of adsorption of a surface-active substance (SAS) from an aqueous electrolyte solution on a metal is proposed on the basis of Bockris' equation taking into account the activity coefficients of the organic compound. The method enables one to calculate the thermodynamic functions related both to the bulk characteristics of the aqueous SAS solution and the properties of the surface layer at the metal–solution boundary. The feasibility of the method is illustrated by the thermodynamic analysis of the experimental data on the adsorbability of tertiary butyl alcohol on an uncharged surface of mercury.

Rheological and electrical properties of fluid PVA-based composites with phosphoric acid are studied. Formation of ordered liquid-crystal structures in the PVA matrix with addition of phosphoric acid to the system is assumed, with the structural ordering dependent on the polymer to acid ratio and solution temperature.

Rheological and electrical properties of polyvinyl alcohol solutions containing copper(II) and cobalt(II) chlorides are studied. Anomalous behavior of these properties is associated with complex formation, depending on the component ratio and temperature.

A technique for calculating standard Gibbs adsorption energies of organic molecules on various metals is proposed. For using the technique in practice, one needs only the parameters of molecules adsorbed on the same metal. The technique is shown to be applicable to estimating the Gibbs adsorption energies on metals with a relatively low hydrophilicity. A model for the surface layer of chemisorbed water molecules and adsorbed molecules of surface active substances (SAS) on uncharged iron is proposed. The available experimental data on the adsorption of SAS on iron can be explained in terms of the model.

The relative yield of variable chlorophyll fluorescence in the bark of annual shoots of woody plants was measured with a portable pulse-modulated fluorometer designed for this purpose at the Department of Biophysics (Biological Faculty, Moscow State University). Experiments were performed to study the response of this parameter to external influences (treatment with an herbicide, water loss, etc.). The results demonstrated the possibility of reliably recording the parameters of fluorescence in the annual shoots of various woody plants without damaging these shoots. It is concluded that measurements of chlorophyll fluorescence in the bark of woody plants can be used for analyzing changes in the physiological state of tree stands under the effects of natural and anthropogenic factors.

The relaxation and new fluctuation effects shown in Mossbauer hyperfine spectra of a Jahn-Teller (JT) ion are briefly discussed. The analysis is carried out in cases of both weak and strong JT coupling.

Some features of the: formation of liquid-crystal structures based on polymer complexes are discussed for composites of polyvinyl alcohol with cellulose esters, polyacids, inorganic acids and variable-valence metals. Rheological and optical methods of research as well as a dielectric relaxation method have revealed the formation of several types of interpolymer complexes in liquid flowable media. This leads to formation of associates and results in an increase of the molecular mobility of macromolecules and their fragments. The structure and properties of the complexes depend on the media compositions and on the method of additive introduction. The composites obtained -can be used for producing light-, electric- and heat-sensitive film materials and sensors of various types.

The scalemic form of active alkaloid (−)-dipthocarpamine was synthesized by asymmetric oxidation ofN-isopropyl-N′-(methylthiohexyl)urea with hydrogen peroxide in the presence of vanadium(IV) complexes with chiral Shiff's bases.

Reaction of 1,2,3,4-tetrafluorodibenz[b,f][1,4]oxazepin-11(10H)-one with nucleophilic reagents (MeONa in refluxing MeOH; piperidine in DMF at 100‡C) leads to substitution of the fluorine atom para to the CONH group. 6,7,8,9-Tetrafluorodibenz[b,f][1,4]oxazepin-11(10H)-one is inert to these conditions.

The influence of crystal field fluctuations on Mossbauer hyperfine spectra is analyzed. These fluctuations lead to violation of cubic symmetry of the environment, to a time-dependent splitting of a quadruplet and, as a consequence, to a temporal modulation of the hyperfine interaction. It is found that fluctuations of E-type do not lead to a complete averaging of the hyperfine interaction in the fast relaxation limit, unlike the case of e.g. magnetic relaxation and any other type of crystal field fluctuations. Moreover, for ions with J=7/2 in the fast relaxation limit the relaxation spectra of Γ8 are identical to the spectra of the Γ8 doublet.

Superoperator equations of Fokker-Planck type, describing the common dynamics of the hyperfine field and the nuclear spin are derived under the conditions of diffusional motion of the magnetic moment of the particles. The solution of this equation in the case of particles with zero energy of magnetic anisotropy is considered. Mossbauer spectra of57Fe nuclei are calculated over a large range of the diffusion coefficient.

The previously unknown mixed thioanhydrides of 1,3-alkylenedithiophosphorous and O,O-dialkyldi-thiophosphoric acids were obtained and some of their chemical properties were studied.

The influence of spin-lattice relaxation on the Mossbauer hyperfine spectra of the Fe3+ ion is investigated in the case of an axial crystal field. All the various influences of the relaxation process on the spectra can be explicitly described using two relaxation parameters. A detailed analysis of the Mossbauer relaxation spectra for the various temperatures, relations between the relaxation parameters and external magnetic field directions is carried out. When the magnetic field direction is nearly collinear with the symmetry axis and one of the relaxation parameters is small, the dynamics of Mossbauer spectra is shown to have anomalous features. The influence of random magnetic fields is shown to give an unconventional development of patterns as a function of the relaxation parameters.

In has been shown in the experiments on male rats that alimentary vitamin E deficit causes the decrease of reduced glutathione and ascorbic acid concentration in the liver and lungs and that of glutathione-S-transferase, glutathione reductase in the liver and lungs, catalase in the liver and glutathione peroxidase in the heart activity, but increases the amount of glutathione disulfide in the liver and lungs and superoxide dismutase and gamma-glutamyltransferase activity in the liver. The data obtained show the selective character of reaction participants of the antioxidant system of rats' organism to the deficit of one of the antioxidant factors--vitamin E and also testify to complex interrelation between separate members of this system.