Study of physico-mechanical properties of epoxy coatings modified with liquid rubbers with terminal carboxyl group

The effect of co-condensation products of low molecular weight carboxylated butadiene and butadienenitrile rubbers with epoxy resin ED-20 on physico-mechanical properties of epoxy-rubber coatings and free films was studied.     

Electrochemical properties of solid electrolytes based on BaSm<Subscript>2</Subscript>S<Subscript>4</Subscript>

Solid solutions based on BaSm₂S_{4 ? x} mol % BaS (Sm₂S₃) are obtained. Oxide intermediates were homogenized using chemical and mechanical mixing methods. The solid solution region is determined. Complex conductivity is studied and conductivity activation energy is calculated for samples with different history. Electrolytic properties of phases based on barium thiosamarate are studied. Vacancy mechanism of defect formation is suggested.     

Relaxation of strains in fibrillar porous carbon dioxide saturated media near their critical point

The isothermal relaxation of strains in deformed fibrillar porous layers saturated with subcritical or supercritical carbon dioxide has been studied at different temperatures by full-field speckle correlometry. The relaxation of strains is produced by the porous layer—fluid transition of a system from one equilibrium thermodynamic state to another due to a jump-like change in pressure. It has been established that the relaxation time attains a maximum near a critical point and rapidly decreases with increasing deviation of the system temperature from its critical value. The mechanisms of hydrodynamic relaxation in the density of a fluid layer and viscoelastic relaxation in a porous matrix are discussed. It is shown that the experimentally observed slow relaxation of a system is due to the viscoelastic relaxation of a porous fluid saturated layer at equal fluid densities inside and outside the layer.     

Synthesis of amino-containing meso-aryl-substituted porphyrins and their conjugates with the closo-decaborate anion

Amphiphilic meso-aryl-substituted porphyrins containing an amino group and long-chain hydrophobic substituents were synthesized. Two strategies of the synthesis of asymmetric amino-containing porphyrins using p-acetamidobenzaldehyde and p-nitrobenzaldehyde were developed and investigated. A series of new substituted porphyrin-containing closo-decaborates were prepared based on the synthesized porphyrins and nitrilium derivatives of the closo-decaborate anion [B₁₀H₁₀]^2?.     

Nano Carrier Drug Delivery Systems for the Treatment of Neuropsychiatric Disorders: Advantages and Limitations

Neuropsychiatric diseases are one of the main causes of disability, affecting millions of people. Various drugs are used for its treatment, although no effective therapy has been found yet. The blood brain barrier (BBB) significantly complicates drugs delivery to the target cells in the brain tissues. One of the problem-solving methods is the usage of nanocontainer systems. In this review we summarized the data about nanoparticles drug delivery systems and their application for the treatment of neuropsychiatric disorders. Firstly, we described and characterized types of nanocarriers: inorganic nanoparticles, polymeric and lipid nanocarriers, their advantages and disadvantages. We discussed ways to interact with nerve tissue and methods of BBB penetration. We provided a summary of nanotechnology-based pharmacotherapy of schizophrenia, bipolar disorder, depression, anxiety disorder and Alzheimer’s disease, where development of nanocontainer drugs derives the most active. We described various experimental drugs for the treatment of Alzheimer’s disease that include vector nanocontainers targeted on β-amyloid or tau-protein. Integrally, nanoparticles can substantially improve the drug delivery as its implication can increase BBB permeability, the pharmacodynamics and bioavailability of applied drugs. Thus, nanotechnology is anticipated to overcome the limitations of existing pharmacotherapy of psychiatric disorders and to effectively combine various treatment modalities in that direction.     

Preliminary structural characterization, anti-inflammatory and anticoagulant activities of chondroitin sulfates from marine fish cartilage

Chondroitin sulfates isolated from cartilage of five marine fish species: Atlantic salmon (Salmo salar), Greenland shark (Somniosus microcephalus), blackmouth catshark (Galeus melastomus), birdbeak dogfish (Deania calcea), and Arctic skate (Amblyraja hyperborea), were characterized in detail by ¹H and ¹³C NMR spectroscopy. The complete signal assignments for carbohydrates were made and the relative contents of the key structural units were estimated by 2D homonuclear and heteronuclear NMR spectroscopy (COSY, TOCSY, NOESY, HSQC, and HMBC). The average length of the polysaccharide chain was evaluated from the integrated intensity ratio of the terminal and internal monosaccharide residues. The anti-inflammatory and anticoagulant activities of the specimens were studied. Chondroitin sulfates from salmon and Arctic skate exhibit considerable anti-inflammatory activity. All specimens manifest weak anticoagulant activity. The results of the present study indicate that chondroitin sulfates deserve more detailed investigation as potential anti-inflammatory agents.     

Fluorescence Study of the Membrane Effects of Aggregated Lysozyme

The last decade has seen unprecedented upsurge of interest in the structural and toxic properties of particular type of protein aggregates, amyloid fibrils, associated with a number of pathological states. In the present study fluorescence spectroscopy technique has been employed to gain further insight into the membrane-related mechanisms of amyloid toxicity. To this end, erythrocyte model system composed of liposomes and hemoglobin was subjected to the action of oligomeric and fibrillar lysozyme. Acrylamide quenching of lysozyme fluorescence showed that solvent accessibility of Trp₆₂ and Trp₁₀₈ increases upon the protein fibrillization. Resonance energy transfer measurements suggested the possibility of direct complexation between hemoglobin and aggregated lysozyme. Using the novel squaraine dye SQ-1 it was demonstrated that aggregated lysozyme is capable of inhibiting lipid peroxidation processes. Fluorescent probes pyrene, Prodan and diphenylhexatriene were employed to characterize the membrane-modifying properties of hemoglobin and lysozyme. Both oligomeric and fibrillar forms of lysozyme were found to exert condensing influence on lipid bilayer structure, with the membrane effects of fibrils being less amenable to modulation by hemoglobin.     

Pontryagin Type Maximum Principle for budget-constrained infinite horizon optimal control problems with linear dynamics

In this paper a class of infinite horizon optimal control problems with an isoperimetrical constraint, also interpreted as a budget constraint, is considered. Herein a linear both in the state and in the control dynamic is allowed. The problem setting includes a weighted Sobolev space as the state space. For this class of problems, we establish the necessary optimality conditions in form of a Pontryagin Type Maximum Principle including a transversality condition. The proved theoretical result is applied to a linear–quadratic regulator problem.