Home – Home – Jornals – Russian Geology and Geophysics 2016 number 5

The paper discusses a possible model of the ancient (Hadean-Archean) Earth’s geodynamic evolution. We believe that the early Earth was characterized by a stagnant lid regime and whole-mantle convection suggesting cells that convect through the whole mantle (from the core-mantle boundary to the lithosphere base). The lid tectonics was perturbed by asteroid-meteorite bombardments that destroyed the primary terrestrial partly granitoid crust. The destroyed crust together with the residual enriched mantle reservoirs sank into the lower mantle. In addition to the crust destruction, the bombardments led to emplacement of a huge proportion of basalt-komatiitic melts, which can be interpreted as mantle overturn events. In the Hadean, the Earth survived frequent large-scale asteroid-meteorite bombardments, which resulted in almost a complete destruction of the primary terrestrial crust. In the Early Archean, the Earth still experienced the same tectonic processes, as in the Hadean; however, meteorite impact was small-scale and the bombardments influenced only a limited area of a common, as it seems to us, subequatorial supercontinent. Those bombardments led to the sagduction of the Archean basalt-komatiiic terrestrial crust, which sank into the mantle, transforming into amphibolite-eclogite rocks giving rise to a tonalite-troondhjemite-granodiorite suite. As preserved in the zircon record, the formation of the Archean mantle-derived magmas occurred as pulses at 4.5, 4.2-4.3, 3.8-3.9, and 3.3-3.4 Ga. These peaks, most likely, correspond to the Hadean-Archean meteorite bombardments. There is evidence of formation of the subcontinental lithospheric mantle (SCLM) beneath the cratons between 3.3 and 3.5 Ga. This SCLM was markedly different from peridotites of modern ophiolites. However, the existence of ophiolitic peridotites indicates that modern style plate tectonic processes were in operation at that time, as we will discuss below. The transition from the early Earth (Hadean-Archean) tectonic style to the recent tectonics occurred between 3.4 (2.7?) and 2.0 Ga.

A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dykes and sills in the formerly attached São Francisco craton (SFC)-Congo craton to yield a short-duration LIP event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (six new herein) from dolerite dikes and sills extending across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age uncertainty of the ID-TIMS ages. Geochemical data indicate a tholeiitic basalt composition with low MgO (4-7 wt.%) within-plate character based on trace element classification diagrams and source between E-MORB and OIB with only minor contamination from crust or metasomatized lithospheric mantle. Two subgroups are distinguished: Group 1 has gently sloping LREE ((La/Sm)_PM = 1.9) and HREE ((Gd/Yb)_PM = 1.8) patterns, slightly negative Sr and moderate TiO₂ anomalies (2.2 wt.%), and Group 2 has steeper LREE ((La/Sm)_PM = 2.3) and HREE ((Gd/Yb)_PM = 2.3), strong negative Sr anomaly, is higher in TiO₂ (2.7 wt.%), and is transitional from tholeiitic to weakly alkaline in composition. The slight differences in REE slopes are consistent with Group 2 on average melting at deeper levels. Proposed reconstructions of the Kuonamka LIP with 1500 Ma magmatism of the SFC-Congo craton are supported by a geochemical comparison. Specifically, the chemistry of the Chapada Diamantina and Curaça dikes of the SFC can be linked to that of Groups 1 and 2, respectively, of the Kuonamka LIP and are consistent with a common mantle source between EMORB and OIB and subsequent differentiation history. However, the coeval Humpata sills and dikes of the Angola block of the Congo craton represent a different magma batch.

The study of the Mesoproterozoic (1473 ± 24 Ma) dolerites of the Olenek uplift of the Siberian craton basement has shown their petrologic and geochemical similarity to typical OIB produced with the participation of a mantle plume. The dolerites are characterized by variations in geochemical composition explained by different degrees of melting of the same source. A conclusion is drawn that the parental melts of the rocks were slightly modified by crustal contamination, as evidenced from their Nd isotope composition (εNd(T) = +0.6 to -0.8) and the presence of inherited zircons of four ages (2564, 2111, 2053, and 1865 Ma). Since the Siberian craton in the structure of the Nuna supercontinent (Columbia) was located relatively close to the Baltic continent and the Congo and Saõ Francisco cratons, we assume that the Early Mesoproterozoic mafic intrusions (1500-1470 Ma) of all these cratons belong to the same large igneous province (LIP). The province formation was related to the activity of superplume (or mantle hot field), which supplied mantle matter to the lithosphere basement. The superplume core was probably located beneath the northern part of the Siberian craton, where basites are compositionally most similar to the primary mantle source.

Phenomena inherent in degenerate branched and completely branched chain reactions are considered from a unified viewpoint. In the case of degenerate branched chain reactions, such phenomena include a negative temperature coefficient, cool flames, and oscillations arising in slow combustion of hydrocarbons. Another phenomenon (intermittent flames) is inherent only in completely branched chain reaction of low-temperature combustion of hydrogen at reduced pressures in the presence of SO₂ additives. These kinetic manifestations of chain branching processes are characterized by a variety of elementary reactions with participation of intermediate compounds and free radicals with different structures. A specific kinetic feature of reactions of both types is simultaneous participation of the active center responsible for chain branching in the branched reaction and in the reaction of propagation of an ordinary chain.

Normal burning velocities in methanol-air mixtures and in the same mixtures with added 4.5 and 7.2% hydrogen as a second fuel were measured over a wide range of equivalence ratio and for initial conditions of 0.16 MPa and 354 K. It has been shown that the mechanism previously proposed for the combustion of mixtures of CO, CH₂O and CH₃OH with air is applicable to multicomponent mixtures containing hydrogen and methanol.

Molecular beam mass spectrometry was used to measure mole fraction profiles of the reactants, major reaction products and intermediates, including precursors of polycyclic aromatic hydrocarbons, in a premixed fuel-rich (equivalence ratio of 1.75) n -heptane/toluene/O2/Ar flame stabilized on a flat burner at atmospheric pressure. The ratio of the liquid volumes in the n -heptane/toluene mixture was7:3. The chemical structure of the flame was modeled using a detailed mechanism of chemical reactions tested against experimental data of other authors on n -heptane/toluene flames and comprising the reactions of formation of polycyclic aromatic hydrocarbons. The mechanism was extended with cross-reactions involving derivatives of n -heptane and toluene. Overall, the new experimental data are in satisfactory agreement with the numerical simulation results; however, there are differences between the measured and calculated mole fraction profiles of some species. Analysis shows that in the n -heptane/toluene flame, the main reactions leading to the formation of low-aromatic compounds (benzene and phenyl) are reactions typical of the pure toluene flame.

A PIV study of a conical premixed methane-air Bunsen flame has shown that the inside of the cone has a complex gas-dynamic structure. In this system, the velocity of the gas flow entering the flame front varies in different parts of the flame cone and the stream tubes are not straight. The Landau-Markstein effect is discussed in the interpretation of the experimental data. A method of processing PIV measurement results is proposed that improves the accuracy of determining the burning velocity and allows a quantitative determination of the catalytic effect of submicron TiO2 particles, which is proportional to the particle surface area. The relative increase in the burning velocity is 2% per each »0.01 cm2/cm3 (particle surface/gas volume) of the total specific surface area of the particles. The experimental data are well described by modeling using well-known literature data on the detailed mechanism of chemical reactions and the mechanism of catalytic oxidation of methane with oxygen on metal oxides.

The influence of an electric field whose intensity vector rotates around the flame axis on the shape of the diffusion flame of propane is experimentally studied. Application of spectrozonal registration makes it possible to obtain information about the radiation intensity distribution at wavelengths of intermediate reaction products (OH, CH, and C2). Different positions of the peak intensity of the own radiation of the flame at different wavelengths testify to the influence of such an electric field on the mixing processes, namely, mixing is more intense than that in the regime without application of the electric field. This feature may turn out to be useful for increasing the efficiency of combustion of gaseous hydrocarbon fuels.

Experimental data on the critical pressure of ignition of titanium alloy fragments in gaseous oxygen are analyzed. The fragments are obtained after fracture of alloy samples in the dynamic mode (p₂*) and under natural convection conditions (p₁*). The results are analyzed with allowance for the heat transfer coefficients from material ignition initiators under similar conditions. Based on the shape of the experimental thermograms of plate cooling, the coefficient of heat transfer from microcraters with a juvenile surface formed due to knockout of metal particles from the plate by the high-velocity flow is found: α₂ ~ 11 W(m² × K). The value of α₂ is close to the value of this coefficient calculated with the use of the coefficient α₁ ~ 5 kW/(m² × K) of heat transfer from titanium rod microfragments (with the size of the order of metal grains) formed during titanium rod fracture in oxygen under conditions of natural convection with allowance for the ratio p₂*/p₁*.

A mathematical model of combustion of a composite solid propellant called ALICE (frozen suspension of nanosized aluminum in water) is presented. The model takes into account the combustion of aluminum nanoparticles in water vapor, the motion of combustion products, and the smaller velocity of particles as compared to the gas. The calculated burning rate is consistent with available experimental data on the burning rate of ALICE as a function of pressure.

The aluminothermic reduction of some oxide systems in the solid-state combustion mode in nitrogen in a high-pressure reactor has been studied for the purpose of obtaining nitride-containing composites. The properties of the synthesis products obtained at various nitrogen pressures were determined.

This paper describes the numerical simulation of combustion with the manifestation of the Vilyunov-Dvoryashin effect that comes down to reduction of the burning rate in the case of blowing of gaseous combustion products past the propellant gasification surface. The cases of endothermic and exothermic reactions of gasification of the solid propellant are considered. The Vilyunov-Dvoryashin effect can terminate combustion even before the erosion coefficient reaches a minimum value of 0.61. Self-oscillating combustion may also occur. The simulation of propellant combustion similar in its properties to the propellant N shows qualitative agreement between the theoretical and experimental results. However, it also reveals the need for more accurate data with regard to performance conditions and experimental results. The existing models of solid-propellant combustion require significant updates as well.

The oxidation kinetics of a diamond powder, P-803 carbon black, and the OSUNT raw material (obtained by electric arc synthesis of single-walled carbon nanotubes) in a stream of steam in the temperature range 600-1315 K was studied. The parameters of the kinetic equations were determined. The temperature dependence of the oxidation rate was found to consist of three regions with different activation energies.

Based on numerical simulations of two-dimensional unsteady flows of gas suspensions, the contribution of particle collisions to dispersion processes during interaction of shock waves with dense dust layers is analyzed. A model of collision dynamics of the two-phase medium based on molecular-kinetic approaches is used. The model is tested by using a problem of a shock wave passing along a dense layer of particles; the model predictions are found to agree well with available experimental data. The problem of interaction of a blast wave with a dense layer on a flat surface is also considered. A comparative analysis of various mechanisms acting on particles and the influence of the initial parameters of the layer on the particle lifting dynamics is performed. A weak effect of the Saffman force and inhomogeneity of the layer surface (waviness) and a significant effect of the Magnus force on dispersion of the layer directly behind the shock wave are demonstrated. In some cases, the contribution of the particle collision dynamics is found to be comparable with the Magnus force effect. Dust lifting due to the development of the Kelvin-Helmholtz instability occurs at late stages of the process.

A mathematical model of synthesis in a mechanically activated SiO₂ + Al mixture is constructed in the macroscopic approximation. It is demonstrated that preliminary mechanical activation makes it possible to obtain solid-phase ignition and to ensure synthesis of Al₂O₃ and Si products in the thermal explosion regime. Based on experimental data, thermophysical and thermokinetic constants of the process are determined.

A superadiabatic regime of the thermal explosion in mechanically activated stoichiometric mixtures of tungsten and carbon black is obtained. Regimes of preliminary mechanical activation of mixtures and the subsequent thermal explosion that allow obtaining a single-phase carbide WC with a submicron grain size are determined. The mechanical energy accumulated in the sample as a result of preliminary activation is estimated. Results of the x-ray diffraction analysis and electron microscopy of mechanically activated samples and thermal explosion products are reported.

The dependences of the critical energy density required to initiate the explosive decomposition of lead azide and the radius of the most heated nanoparticle on the pulse duration of the first harmonic of neodymium laser (1064 nm) are calculated within the framework of the micro-hotspot model of thermal explosion. The calculations are carried out with account for the dependence of the absorption efficiency factor of the laser pulse on the lead nanoparticle radius. With the maximum value of the absorption efficiency factor (1.18), the lead nanoparticle radius (in lead azide) becomes 74 nm. If the pulse duration is short (smaller than 40 ns), the radius of the most heated lead nanoparticle in the lead azide matrix varies slightly (less than 15%) and equals 63.5 nm within the range of short pulse durations. Accounting for the dependence of the absorption efficiency factor of the laser pulse on the nanoparticle radius makes it possible to resolve the paradox of small particles.

Mass velocity profiles of detonation waves in mixtures of nitromethane with acetone and methanol with added diethylenetriamine sensitizer were measured using a VISAR laser interferometer. It was found that even small, about 1%, concentrations of acetone and methanol, inert diluents, led to instability of the one-dimensional detonation front in nitromethane. The results of the experiment show that the use of the sensitizer is an effective method of flow stabilization and if the concentration of the inert diluent does not exceed 10%, the detonation front becomes stable with the addition of 1% diethylenetriamine. At a higher diluent concentration, the sensitizer does not suppress the instability but decreases the oscillation amplitude by several times. The addition of diethylenetriamine to the mixture has been found to increase the detonation velocity.

The temperature of a shock-compressed invert emulsion based on an aqueous solution of ammonium and sodium nitrates was measured using two experimental techniques: using planar thermocouples at pressures of 3.4-12.0 GPa and optical pyrometry at pressures of 9-22 GPa. The experimental data obtained using the thermocouple method are consistent with the calculated values. The optical measurement results are significantly higher than the calculated data and indicate the presence of a spatially inhomogeneous temperature field behind the shock front in the emulsion due to the structural inhomogeneity of the medium.

It has been found that gold mine waste in the Amur River Area (Priamurye, Russian Far East) contain associated minerals of gold belonging in the group of useful components. In view of the complicated nature of the mine waste, it is decided on the appraisal and recovery of the associated useful components with the help of rational technologies.

The article describes the research results on evaluation of rational technological parameters for open pit mining of Oshkurkovskoe apatite deposit using Wirtigen Surface Miners. Basic relations between the surface miner capacity, ground conditions and technological factors are substantiated. The authors have constructed lag models and determined optimal design capacity of open pit mine.

The authors analyze feasibility of voltage stabilization for permanent magnet synchronous generators in independent variable-frequency power networks. The method of voltage stabilization is based on series connection of the generator and a semiconductor converter generating wattles power. Basic energy characteristics of the semiconductor converter and synchronous generator are analytically defined, frequency constraints of the proposed method are found, and rational frequency range and overall power of the system are determined.

Electrical insulation of open pit shovels has been tested. It is found that line-to-ground short circuit current in up to 1000 V network is lower than setting current of safety cut-out. The authors propose a method to improve efficiency of safety cut-out of mining shovels and drill rigs. The method is based on superimposing D/C current on three-phase network with fixed setting of cut-out operation, i.e. when a person touches live parts the electrics is cut-out owing to increase in capacitance of phase relative to ground.

The article gives new experimental data on spectral characteristics of photoluminescence of natural diamonds extracted from deep horizons of Mir and Internatsionalnaya Pipes, Republic of Sakha (Yakutia) depending on composition of basic and additional optically active structural defects in crystals and on temperature during spectrum recording, considering kinetics of luminescence. It is hypothesized on applicability of low-temperature effects to enhance efficiency of photoluminescence separation of diamond crystals.

From the analysis of information on flotation of quartz, barite, hematite and diamond spar using cationic reagents (amines), the authors show deficiency of thermodynamic approach to explain flotation results by one type of adsorption due to ion-electrostatic mechanism. The discussion offers hypothesis that says that at low pH collecting ability of a reagent is connected with hydrophobic attachment of reagent ions in adsorption layer. In alkaline range of pH, the collecting ability is conditioned by formation and precipitation of ion-molecular associates in the adsorption layer of a mineral. These types of adsorption attach particle surface which is preliminarily made hydrophobic by ion-electrostatic mechanism. These adsorption types are active at bubble-liquid interface and can go to this interface upon rupture of water film between a particle and a bubble. According to the suggested hypothesis, liquid tension in the film becomes nonuniform and a surface force arises and expels kinematic constraint for particle-bubble attachment. The analytical review of the collected test data on cationic reagents proves the suggested hypothesis. The causes of breakdown of correlation between surface pressure and collecting ability for initial conditions of flotation are explained.

Air bubble and pyrite grain attachment is studied. It is found that mineralization area on air bubble depends on pulp agitation time, potassium butyl xanthate concentration and pyrite grain size. The authors show the connection between mineralization area of air bubble and weight of mineral load. Using experimental data, it is calculated how many pyrite grains from a narrow size range attach air bubble during pulp agitation time, and the weight of these grains is estimated. Physical forces on mineral loading exerted by pyrite grains -_{0.1 + 0.071, - 0.071 + 0.044 and -0.044 + 0 mm in size on air bubble at different pulp agitation times, as well as the absolute and specific retention forces are calculated, too.}

The article gives analytical and experimental data on separation of sulfide minerals in bulk concentrates of complex ores. The separation methods for minerals having similar process properties are selected. It is found which factors influence mineral separation efficiency in concentrates of rebellious and complex ore processing. The authors present fresh data on activating effect exerted by cations of copper on floatability of sphalerite, galena, pyrite and pyrrhotine species, as well as on activating effect of copper minerals. It has been studied how species of pyrite and nonferrous metal sulfides influence oxidation, floatability and depression. The selected methods to separate complex ore concentrates provide for multi-stage flotation circuit, with recovery of rebellious species into rough concentrates and products and their separation in different cycles later on. A system mode has been developed and recommended for dosing selective collectors, depressors and modifiers to achieve the best flotation performance.

The article describes theoretical and experimental data on dearsenation of gold-containing scorodite ore in water vapor. It is shown that roasting of scorodite with pyrite in super-heated vapor enables complete removal of arsenic and sulfur in the form of sulfides of the original material and exposes noble metals.

The author performs the comparative analysis of the international standards on determination of elastic properties of rocks from uniaxial compression tests, with benefits and shortcomings of the standards presented. The measurement data on lateral and transverse strains obtained in rocks and model metal samples under compression using different type extensometers are reported. The scope of the analysis embraces applicability of extensometers to the determination of elasticity modulus and Poisson’s ratio in rocks under variation in temperature. Examples of estimating elastic properties in thawed and frozen rocks are given in terms of enclosing rocks at Botuobinskaya diamond pipe.

The designed automated system for pitwall deformation monitoring consists of an independent data recorder, strain sensors, AD converters, and front-end and back-end controls. Data are accumulated in server in on-line mode via cellular modem. The self-contained tools are supplied from accumulators recharged by solar batteries, which expands operational life of the system. The system has been trailed in an open pit mine at Nyurbinskaya kimberlite pipe in deformation monitoring of faults in the eastern pitwall and estimation of its geomechanical stability.

The authors prove relevance of digital space data to be used for regional and local operational quantitative estimation of nature in the area of mining and processing. The research findings are analyzed in terms of environmental appraisal for the area of an open pit mine at Gusevogorskoe deposit of titano-magnetite ore with vanadium admixture (Sverdlovsk Region, Russia).

The article gives new information on integrated assessment of the environmental impact of mining in the south of Russia’s Far East. The assessment is based on: Earth remote sensing data; normalized difference vegetation index for nature-technology systems; combination of the calculated vegetation index and digital relief model to implement individual estimation of the induced impact and natural effects; joint analysis of the induced impact based on satellite monitoring and field survey data; computation of ecological-and-economic damage.

Objective. To study the effect of sesquiterpene γ-lactone achillin on the lipid content and mRNA expression of key genes of lipid metabolism in the hepatoma tissue cell line HTC in the experimental hyperlipidemia. Materials and methods. The experimental hyperlipidaemia in HTC cells simulated by adding fat emulsion Lipofundin MCT/LCT at a final concentration 0.05 % to the incubation medium. After 48 h of incubating cell culture with achillin at the final concentration 500 μM the cell viability was investigated by using the MTT assay and assessed level of lipids by fluorescent vital stain Nile Red and the content of triacylglycerols (TAG) and cholesterol by enzymatic method. RNA was isolated from cells using the set Illustra RNAspin Mini RNA Isolation Kit («GE Healthcare»). The level of mRNA expression of key genes in lipid metabolism was assessed using a real-time quantitative polymerase chain reaction with reverse transcription by TaqMan technology. Results. Incubation cells with Lipofundin MCT/LCT (0.05%) resulted in an increase in the fluorescence intensity of Nile Red and increase the levels of TAG in cells. Achill (500 µM) had no cytotoxic effect on HTC cell and led to reduction of cholesterol and TAG in cells with hyperlipidemia induced by Lipofundin. This was accompanied by a decrease in fluorescence intensity of Nile Red dye in the cells. In the hepatoma culture achillin increased gene expression of carnitine palmitoyltransferase 1 (Cpt1a) and 2 (Cpt2) , 7-alpha-hydroxylase (Cyp7a1) and 3-hydroxy-3-methylglutaryl CoA reductase (Hmgcr) . On expression of gene acetyl-CoA cholesterol acyltransferase (Soat1) achill had an inhibitory effect. Conclusion. Lowering of cholesterol, TAG and Nile Red fluorescence intensity in hepatoma cells in experimental hyperlipidemia under the action of achillin in the final concentration 500 µM could be caused by increase of gene expression carnitine palmitoyltransferase 1 and 2; 7-alpha-hydroxylase, which contributes to increase the transport of fatty acids into the mitochondria, and synthesis of bile acids from cholesterol. In addition, inhibition of acetyl-CoA cholesterol acyltransferase helps to reduce the formation of cholesterol esters and their accumulation in the hepatocytes.

The aim of this study was to investigate associations of meteorological factors with complications of hospital stage of acute myocardial infarction in Surgut city. 337 consecutive patients (278 men and 59 women), mean age 53,7 ± 8,9 years, with acute myocardial infarction (AMI) with ST-segment elevation were examined. In the group of female patients with AMI the early post-infarction angina was positively correlated with the maximum atmospheric pressure in the debut day of AMI (r = 0,294, p = 0,028). Using binary logistic regression (χ²=14,7, p=0,002) we revealed that the deaths in patients with AMI positively depends on the aged (p = 0,001), minimum level of atmospheric pressure in the period from the start of AMI to the end of hospital stage (p = 0,039). It was found that the occurrence of pulmonary edema in women with AMI is directly dependent on the level of minimum atmospheric pressure in the period from the start of AMI to the end of the hospital stage (p = 0,032).

The aim of the study. Study of electrophysiological signs ofmyocardial metabolic disorders (MMD) and the search for their associations with metabolic syndrome (MS) in men with coronary atherosclerosis (CA). Materials and methods. The study included 123 men with stenotic CA, verified during coronary angiography (CAG), without acute coronary syndrome (ACS) and with stable angina functional class (FC) II-IV.Was spend ECG alone in 12 standard leads. We analyzed ECG signs of MMD (length of the interval QT, above the contour >5mm, ST segment depression below the contour >5mm non-ischemic type, T-wave changes, syndrome TV1> TV6, signs of left ventricular hypertrophy (LVH), arrhythmias and asequence). Evaluated components and markers MS: waist circumference (WC), body mass index (BMI), systolic and diastolic blood pressure (SBP, DBP) blood levels of total cholesterol (TC), cholesterol of lowand high-density lipoproteins (LDL-cholesterol, HDL-cholesterol), c-peptide, and glucose, tumor necrosis factor (TNF-alpha), interleukin 6 (IL-6). Results and discussion. It was found that men with a significant stenotic atherosclerosis of one or more branches of the coronary arteries has a high incidence of MS (69%), its features / components and nonspecific ECG signs of MMD. In addition, men with SC and MS or with the frequency component of the electrophysiological signs MMD ECG signs of LVHand syndrome TV1> TV6 higher by more than 1.5 times in comparison with the absence of MS. Conclusion. Results of the study reflect the impact of common metabolic disorders in the body of the emergence and development of not only the metabolic syndrome, and metabolic myocardial damage.

Earlier research revealed that the decrease in ankle-brachial index (ABI) indicates the presence of atherosclerosis of the arteries of the lower extremities and increased risk of cardiovascular events, including stroke risk. Less studied is the relationship of ABI with clinical manifestations of stroke, the effect on recovery of neurological deficit. Therefore, the aim of the present study was to evaluate the relationship between pathological ABI and clinical outcomes of acute disorders of cerebral circulation (cerebral vascular accident) by the time of discharge from the hospital. Materials and Methods: The study included 375 patients after stroke. All patients underwent investigation of the state of the peripheral arteries using the device VaSera VS-1000 (Fukuda Denshi, Japan). Patients evaluated the presence of cardiovascular disease, previously vascular events, type and subtype of stroke. Also assessed neurological status with neurological scales: NIHSS, Barthel, Rankin, Ashworth, mobility index Rivermid and test swallowing. Cognitive function was assessed by Mini-Mental State Examination (MMSE). Results: In patients with abnormal ABI often identified ischemic stroke (99.4%). The study found that patients with abnormal levels of ABI (1.3 <ABI <0.9) often have concomitant cardiovascular disease. It was found that the speech disorders, central paresis of muscles of the face, tongue, and paresis of the extremities are more common in patients with a pathological ABI. In assessing the neurological deficit via neurological scales, patients with abnormal levels of ABI also showed poorer results on the scales MMSE, NIHSS, Barthel and Rankin. Conclusions: Pathological ABI values were detected in almost half of patients who have suffered acute violation of cerebral circulation. In patients with pathological ABI the restoration of disturbed functions runs worse compared with patients who had normal ABI. Also, this group of patients has a more pronounced cognitive impairment compared with the group with normal ABI.

Primary health prevention of cardiovascular disease is a major focus of preventive measures among the population. In order to develop the most appropriate and effective preventive measures it is advisable to study the characteristics of the population based on the formation of the socio-demographic profile, using a sociological survey method.

Purpose. To evaluate the effect of the changed living conditions during the last decade, the prevalence of obesity as a risk factor for cardiovascular disease among residents of Mountain Shoria. Materials and methods. During the periods since 1998 till 2002 and since 2012 till 2015 in field conditions by continuous method we examined 1215 and 774 inhabitants correspondingly in the outlying hard-to-reach villages of Mountain Shoria. About half of them was represented by indigenous inhabitants - Shors, the other half by more than 95% was represented by Russians. The examination included: clinical examination, measurement of height, body mass, waist circumference (WC), hip circumference (HC), body mass index, WC/HC index. Obesity diagnosis was made in accordance with WHO criteria (1997). Results. During all the examination periods women of non-indigenous nationality revealed obesity more often (3.9% of obesity cases among Shor women, 31.3% cases among non-Shor women over the period since 1998 till 2002 (р=0.0001), 7.3% of obesity among indigenous female inhabitants and 31.4% among non-indigenous women over the period since 2012 till 2015 (р=0.0001)). Over the last 15 years a number of individuals with obesity and overweight has significantly increased: the percentage of men with obesity (over the period since 1998 till 2002 - 0.8% of Shor and 2.4% of non-Shor men had BMI≥30 kg/m2 (р=0.072), as compared to 2012-2015 period - 7.3% of Shor and 27% of non-Shor men had obesity (р=0.00001). Among Shor women the percentage of obese individuals increased significantly at the age of 40-49, 60-69 and over 70 years old. In representatives of male indigenous population the number of obese individuals increased significantly at the age of 40-49 years old, in non-Shor men - at the age of 18-29, and 30-39 years old. Conclusion. Regardless of gender and ethnicity the number of individuals with overweight and obesity increased significantly among the inhabitants of Mountain Shoria, as well as the value of WC/HC index, especial among Shor women.

The metabolic syndrome and visceral obesity have an increasing prevalence and incidence in the generalpopulation. The actual prevalence of the metabolic syndrome is 24% in US population and between 24,6% and 30,9% in Europe. As demonstrated by many clinical trials (NAHANES III, INTERHART) the metabolic syndrome is associated with an increased risk of both diabetes and cardiovascular disease. In addition to cardiovascular disease, individual components of the metabolic syndrome have been linked to the development of cancer, particularly to colorectal cancer. Colorectal cancer is an important public health problem; in the year 2000 there was an estimated total of 944717 incident cases of colorectal cancer diagnosed world-wide. This association is sustained by many epidemiological studies. Recent reports suggest that individuals with metabolic syndrome have a higher risk of colon or rectal cancer. Moreover, the clusters of metabolic syndrome components increase the risk of associated cancer. The physiopathological mechanism that links metabolic syndrome and colorectal cancer is mostly related to abdominal obesity and insulin resistance. Population and experimental studies demon trated that hyperinsulinemia, elevated C-peptide, elevated body mass index, high levels of insulin growth factor-1, low levels of insulin growth factor binding protein-3, high leptin levels and low adiponectin levels are all involved in carcinogenesis. Understanding the pathological mechanism that links metabolic syndrome and its components to carcinogenesis has a major clinical significance and may have profound health benefits on a number of diseases including cancer, which represents a major cause of mortality and morbidity in our societies.

This article is devoted to discussion about main aspects of current use of non-statin hypolipidemic drugs according last international guidelines (including fibrates, nicotinic acid, resins, polyunsaturated fatty acids, ezetimibe, PCSK9-inhibitors). For each group mechanism of action, effects on lipid profile, main results of randomized trials and practical use approaches are shortly represented.