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Regular version of the site
Of all publications in the section: 600
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Article
Pouvreau M., Greathouse J. A., Cygan R. T. et al. The Journal of Physical Chemistry C. 2019. Vol. 123. P. 11628-11638.

Toward the development of classical force fields for the accurate modeling of clay mineral-water systems, we have extended the use of metal–O–H (M–O–H) angle bending terms to describe surface Si–O–H bending for hydrated kaolinite edge structures. Kaolinite, comprising linked octahedral Al and tetrahedral Si sheets, provides a rigorous test by combining aluminol and silanol groups with water molecules in hydrated edge structures. Periodic density functional theory and classical force fields were used with molecular dynamics to evaluate the structure, dynamics, hydrogen bonding, and power spectra for deriving optimum bending force constants and optimal equilibrium angles. Cleavage energies derived from density functional theory molecular dynamics calculations indicate the relative stabilities of both AC1 and AC2 edge terminations of kaolinite where Si–OH and Al–(OH2) or Si–OH, Al–OH, and Al–(OH2) groups exist, respectively. Although not examined in this study, the new Si–O–H angle bending parameter should allow for improved modeling of hydroxylated surfaces of silica minerals such as quartz and cristobalite, as well as amorphous silica-based surfaces and potentially those of other silicate and aluminosilicate phases.

Added: Nov 2, 2019
Article
Chernyshov A., Spicher A., Ilyasov A. et al. Physics of Plasmas. 2018. Vol. 25. No. 4. P. 042902-10.

Microprocesses associated with plasma inhomogeneities are studied on the basis of data from the Investigation of Cusp Irregularities (ICI-3) sounding rocket. The ICI-3 rocket is devoted to investigating a reverse flow event in the cusp F region ionosphere. By numerical stability analysis, it is demonstrated that inhomogeneous-energy-density-driven (IEDD) instability can be a mechanism for the excitation of small-scale plasma inhomogeneities. The Local Intermittency Measure (LIM) method also applied the rocket data to analyze irregular structures of the electric field during rocket flight in the cusp. A qualitative agreement between high values of the growth rates of the IEDD instability and the regions with enhanced LIM is observed. This suggests that IEDD instability is connected to turbulent non-Gaussian processes. Published by AIP Publishing.

Added: Nov 28, 2019
Article
Chernyshov A., Chugunin D. V., Mogilevsky M. M. et al. Acta Astronautica. 2020. Vol. 167. P. 455-459.

The principal possibility to measure the plasma density and its fluctuations in the ionosphere on ultra-small space vehicles using radiophysical methods is shown. These methods allow us to determine the characteristics of the medium by the properties of the received radiation. It is assumed that each small spacecraft has a satellite navigation receiver as well as a device for emitting and detecting a signal at two multiple frequencies in the radio band. In this approach, information on plasma density is contained in the received phase difference. Radio receivers and radio transmitters on satellites constantly exchange radio signals and then it is possible to determine the plasma density and its fluctuations from the phase shift. Numerical estimates are also made to determine the maximum distance between satellites where one can reliably receive a radio signal.

Added: Dec 5, 2019
Article
Chernyshov A., Kozelov B., Mogilevsky M. M. Journal of Atmospheric and Solar-Terrestrial Physics. 2017. Vol. 161. P. 127-133.

In this work, values of the fractal dimension and the connectivity index characterizing the structure of Hall conductivities on the night side of the auroral ionosphere are derived in general form. Restrictions imposed on fractal structure of the ionospheric conductivity are analyzed in terms of the percolation of the ionospheric Hall currents. It is shown that the structure of ionospheric Hall conductivities can be described as asymptotically path connected fractal. This result is supported by analysis of typical structure observed in auroral electron precipitation which are also the main source of ionization on the night side of the ionosphere. It is demonstrated that crossing the precipitation region in the direction perpendicular to the multiple arcs system, one should observe the structure of the precipitation which looks like a generalized Cantor set.

Added: Nov 28, 2019
Article
Zakharov V., Trofimov I., Minin A. A. Russian Journal of Developmental Biology. 2018. Vol. 49. No. 1. P. 1-11.

⎯The study of the indices of developmental homeostasis in natural populations leads to the definition of the fundamentals of population developmental biology, which is associated with the assessment of the nature of phenotypic diversity and the mechanisms of population dynamics and microevolutionary changes. Characterization of environmental quality based on the assessment of population status by developmental homeostasis determines the fundamentals of the health of environment concept. The use of the ideas of developmental homeostasis and the health of environment in the studies of homeostatic mechanisms of biological systems of different levels (from the organism and population to the community and ecosystem) is promising. This gives new opportunities for understanding the mechanisms that provide sustainability and their ratio at different levels as well as for the characterization of ontogenetic stability significance. The notion of developmental homeostasis, or homeorhesis, is promising for the elaboration of the ecological and biological basics of sustainable development.

Added: Feb 26, 2018
Article
Idrissi A., Kiselev M. G., Kalinichev A. G. Journal of Molecular Liquids. 2017. Vol. 239. P. 1-2.

Professor Yuri E. Gorbatywas born 30 July 1932 in the city Grozny, in the Soviet Union. He has graduated from the Mendeleev Institute of Chemical Technology,Moscow, in 1955. He has got his Candidate of Sciences (Ph.D.) degree in 1963 for his work on “Non-equilibrium crystallization of the three-componentmelts”, and later in 1988 he was awarded a Doctor of Sciences degree for the work “The effect of temperature and pressure on the nearest ordering in liquid and supercritical water”. Between these two dates and then later in his scientific career Yuri E. Gorbaty has become one of the leading experts in the field of experimental studies of the structure and properties of fluids, especially aqueous fluids at high temperatures and pressures, by methods of IR and Raman spectroscopy and by X-ray diffraction.

Added: Jul 13, 2017
Article
Thornbush M., Golubchikov O., Bouzarovski S. Sustainable Cities and Society. 2013. Vol. 9. P. 1-9.

This paper examines recent literature on achieving sustainable cities that incorporate a combined mitigation–adaptation approach towards improved urban resilience as a way of future-proofing. A multidisciplinary approach, which integrates scientific as well as ecopolitical frameworks, is found to benefit this sustainability discourse.

Added: Oct 9, 2014
Article
Ilina I. N., Голубчиков Ю. Н., Маркова О. И. et al. International Journal of Sustainable Development and World Ecology. 2016. Vol. 23. No. 5. P. 1-10.

The article discusses the modern periglacial environment of high-latitude and high-altitude regions that extends from the cold limits of forest to the snowline. Within a compact space, several sharply contrasting mountain landscape belts interchange. Living organisms there are particularly affected by cosmic and random-destructive forces. Precisely in these areas, various global geographical, geological, and biological problems are manifested most vividly. The upper limits of agriculture and their importance for high-altitude areas in the main mountain systems of the world are considered. Tourism changes the periglacial environment approach paradigm from the use- and risk-management perspective to the axiological, with attractive categories, angle.

Added: Aug 23, 2016
Article
Ермоленко Г. В., Proskuryakova L. N., Ермоленко Б. В. Foresight. 2017. Vol. 19. No. 5. P. 528-540.

Purpose – The purpose of the study is to show the technical potentials of a variety of renewable energy sources in Russia, as well as benefits from their deployment including hydrocarbon savings, emission reduction and lower energy cost. Design/methodology/approach – In the paper, Russia is compared with other countries in terms of actual installed capacity and its dynamics, actual and projected share of renewables in the energy mix. The authors offer calculations of the technical potentials (fuel, heat energy, electrical energy, resource saving and environmental) of renewables (solar PV, wind, biomass, geothermal, low-grade heat, small hydro), identify social and economic preconditions and key effects of their deployment. Findings – The paper features calculations on the renewable energy technology potential, based on the data by Andreenko et al. (2015), authors’ calculations and statistical data. This study proves that the cumulative technical potential of the renewables in Russia amounts to 133,935 million units of oil equivalent. This study also offers assessments of oil fuel, black coal and natural gas savings that may be achieved by replacing fossil fuels with renewables; assessments of avoided air pollution calculated as CO- and CO2-equivalents. Originality/value – The paper fills in the gap of comprehensive assessments of renewable energy potentials in Russia and a variety of effects that their deployment may entail, based on a single integral methodology. The authors offer a new evaluation of existing and future renewable energy potentials, overcoming the methodological and data constraints faced by previous similar studies. The up-to-date, comprehensive and accurate data will help make the right investment and policy choices.

Added: Sep 25, 2017
Article
Lavrenov S., Luzikov Y., Bykov E. et al. Bioorganic and Medicinal Chemistry. 2010. Vol. 18. No. 18. P. 6905-6913.

Novel derivatives of tris(indol-3-yl)methane and tris(indol-3-yl)methylium salts with the alkyl substituents at the N-atoms of the indole rings were synthesized. An easy substitution of indole rings in trisindolylmethanes for other indoles under the action of acids is demonstrated, and the mechanism of substitution is discussed. To obtain trisindolylmethylium salts, the environmentally safe method of oxidation of trisindolylmethanes with air oxygen in acidic conditions was developed. Tris(1-alkylindol-3-yl)methanes and tris(1-alkylindol-3-yl)methylium salts represent three-bladed molecular propellers whose physico-chemical and biological properties strongly depend on the N-alkyl substituent. The cytotoxicity of novel compounds increased with the number of C atoms in the alkyl chains, with optimal number n = 3-5 whereas the derivatives with longer side chains were less cytotoxic. The most potent novel compounds killed human tumor cells at nanomolar-to-submicromolar concentrations, being one order of magnitude more potent than the prototype antibiotic turbomycin A [tris(indol-3-yl)methylium salt]. Apoptosis in HCT116 colon carcinoma cell line induced by tris(1-pentyl-1H-indol-3-yl)methylium methanesulfonate was detectable at concentrations tolerable by normal blood lymphocytes. Thus, N-alkyl substituted tris(1-alkylindol-3-yl)methylium salts emerge as perspective anticancer drug candidates. 

Added: Jul 14, 2015
Article
Shchekotikhin A., Glazunova V.A., Dezhenkova L. et al. Bioorganic and Medicinal Chemistry. 2009. Vol. 17. No. 5. P. 1861-1869.

We developed the synthesis of a series of thiophene-fused tetracyclic analogues of the antitumor drug ametantrone. The reactions included nucleophilic substitution of methoxy groups in 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-diones with ethylenediamines, producing the derivatives of 4,11-diaminoanthra[2,3-b]thiophene-5,10-dione in good yields. Several compounds showed marked antiproliferative potency against doxorubicin-selected, P-glycoprotein-expressing tumor cells and p53-/- cells. The cytotoxicity of some novel compounds for P-glycoprotein-positive cells is highly dependent on N-substituent at the terminal amino group of ethylenediamine moiety. The cytotoxic potency of selected compounds correlated with their ability to attenuate the functions of topoisomerase I and telomerase, strongly suggesting that these enzymes are the major targets of antitumor activity of anthra[2,3-b]thiophene-5,10-dione derivatives.

Added: Jul 14, 2015
Article
Shchekotikhin A., Glazunova V.A., Dezhenkova L. et al. European Journal of Medicinal Chemistry. 2014. Vol. 86. P. 797-805.

A series of new 3-aminomethyl-411-dihydroxynaphtho[2,3-f]indole-5,10-diones 6-13 bearing the cyclic diamine in the position 3 of the indole ring was synthesized. The majority of new compounds demonstrated a superior cytotoxicity than doxorubicin against a panel of mammalian tumor cells with determinants of altered drug response, that is, Pgp expression or p53 inactivation. For naphtho[2,3-f]indole-5,10-diones 6-9 bearing 3-aminopyrrolidine in the side chains, the ability to bind double-stranded DNA and inhibit topoisomerases 1 and 2 mediated relaxation of supercoiled DNA were demonstrated. Only one isomer, (R)-4,11-dihydroxy-3-((pyrrolidin-3-ylamino)methyl)-1H-naphtho[2,3-f]indole-5,10-dione (7) induced the formation of specific DNA cleavage products similar to the known topoisomerase 1 inhibitors camptothecin and indenoisoquinoline MJ-III-65, suggesting a role of the structure of the side chain of 3-aminomethylnaphtho[2,3-f]indole-5,10-diones in interaction with the target. Compound 7 demonstrated an antitumor activity in mice with P388 leukemia transplants whereas its enantiomer 6 was inactive. Thus, 3-aminomethyl derivatives of 4,11-dihydroxynaphtho[2,3-f]indole-5,10-dione emerge as a new prospective chemotype for the search of antitumor agents. © 2014 Elsevier Masson SAS.

Added: Jul 14, 2015
Article
Kertesz-Farkas A., Noble W. Journal or Proteome Research. 2015. Vol. 14. No. 8. P. 3027-3038.
Added: Sep 25, 2015
Article
Chugunov A., Volynsky P., Krylov N. et al. Scientific Reports. 2016. Vol. 6. No. 33112. P. 1-16.

Heat-activated transient receptor potential channel TRPV1 is one of the most studied eukaryotic proteins involved in temperature sensation. Upon heating, it exhibits rapid reversible pore gating, which depolarizes neurons and generates action potentials. Underlying molecular details of such effects in the pore region of TRPV1 is of a crucial importance to control temperature responses of the organism. Despite the spatial structure of the channel in both open (O) and closed (C) states is known, microscopic nature of channel gating and mechanism of thermal sensitivity are still poorly understood. In this work, we used unrestrained atomistic molecular dynamics simulations of TRPV1 (without N- and C-terminal cytoplasmic domains) embedded into explicit lipid bilayer in its O- and C-states. We found that the pore domain with its neighboring loops undergoes large temperature-dependent conformational transitions in an asymmetric way, when fragments of only one monomer move with large amplitude, freeing the pore upon heating. Such an asymmetrical gating looks rather biologically relevant because it is faster and more reliable than traditionally proposed "iris-like" symmetric scheme of channel opening. Analysis of structural, dynamic, and hydrophobic organization of the pore domain revealed entropy growth upon TRPV1 gating, which is in line with current concepts of thermal sensitivity.

Added: Nov 11, 2016
Article
Kychkin A., Krysin N., Krivoshchekov S. et al. Neftyanoe Khozyaistvo - Oil Industry. 2016. No. 12. P. 136-139.

The article describes testing of dispatching module of developing telemetry system of well borehole trajectory monitoring for well drilling with use of rotary steerable system. A scheme of reliability evaluation and a stand for load testing of program apparatus complex of surface equipment are discussed. A scheme includes communication controller, input module, and operator’s station and power supplies. These functional units, connected in series, create dispatching system with performance parameters that may be evaluated by continuous formation, sending, processing and saving of recorded data on well state. A well is modeled on regimes close to real production on a drill site. Load testing on stand consist of formation and sending of data array from communication controller to an operator’s station. An array carries time label with date and time, coordinates in metrical notation system and attributes – data about odometry, azimuthal angles and temperature. Modeling signals on well trajectory and additional attribute parameter, arrived to dispatching module, provide automated test regime of program apparatus complex of surface equipment of dispatching module and allow revealing elements that decrease general reliability of entire system of telemetry monitoring on development stage. During continuous load testing failures of program code of operator’s station are found. Border conditions when a system maintains reliable state during long time and parameters of information transmission rate are determined. Based on scheme of series connection reliability of dispatching system main parameters of reliability are calculated.

Added: Nov 25, 2018
Article
Yemelina Natalya K., Kudryavtsev S. S., Yemelin P. V. Safety and Health at Work. 2018. Vol. 9. No. 1. P. 30-41.

Background: The purpose of the work is to develop a system that allows processing of information for analysis and industrial risk management, to monitor the level of industrial safety and to perform necessary measures aimed at the prevention of accidents, casualties, and development of professional diseases for effective management of industrial safety at hazardous industrial sites. Methods: Risk assessment of accidents and incidents is based on expert evaluations. Based on the lists of criteria parameters and their possible values, provided by the experts, a unified information and analytical database is compiled, which is included in the final interrogation questionnaires. Risk assessment of industrial injuries and occupational diseases is based on statistical methods. Results: The result of the research is the creation of Guidelines for risk management on hazardous industrial sites of the Republic of Kazakhstan. The Guidelines determine the directions and methods of complex assessment of the state of industrial safety and labor protection and they could be applied as methodological basis at the development of preventive measures for emergencies, casualties, and incidents at hazardous industrial sites. Conclusion: Implementation of the information-analytical system of risk level assessment allows to analyze the state of risk of a possible accident at industrial sites, make valid management decisions aimed at the prevention of emergencies, and monitor the effectiveness of accident prevention measures.

Added: Apr 20, 2019
Article
Linder D. P., Silvernail N. J., Barabanschikov A. et al. Journal of the american chemical society. 2014. Vol. 136. No. 28. P. 9818-9821.

Heme-carbonyl complexes are widely exploited for the insight they provide into the structural basis of function in heme-based proteins and enzymes, by revealing the nature of their bonded and nonbonded interactions with the protein. This report presents two novel results which, taken together, clearly establish a FeCO vibrational signature for crystallographically verified penta-coordination. First, anysotropy in the NRVS density of states for \nu_{Fe-C} and \delta_{FeCO} in oriented single crystals of [Fe(OEP)(CO)] clearly reveals that the Fe-C stretch occurs at higher frequency than the FeCO bend and considerably higher than any previously reported heme carbonyl. Second, DFT calculations on a series of heme carbonyls reveal that the frequency crossover occurs near the weak trans O-atom donor, furan. As \nu_{Fe-C} occurs at lower frequencies than \delta_{FeCO} in all heme protein carbonyls reported to date, the results reported herein suggest that they are all hexacoordinate.

Added: Mar 14, 2016
Article
Sawada T., Petrov A. A. Journal of Neurophysiology. 2017. Vol. 118. P. 3051-3091.

This is a review study.  The physiological responses of simple and complex cells in the primary visual cortex (V1) have been studied extensively and modeled at different levels. At the functional level, the divisive normalization model (DNM; Heeger DJ. Vis Neurosci 9: 181–197, 1992) has accounted for a wide range of single-cell recordings in terms of a combination of linear filtering, nonlinear rectification, and divisive normalization. We propose standardizing the formulation of the DNM and implementing it in software that takes static grayscale images as inputs and produces firing rate responses as outputs. We also review a comprehensive suite of 30 empirical phenomena and report a series of simulation experiments that qualitatively replicate dozens of key experiments with a standard parameter set consistent with physiological measurements. This systematic approach identifies novel falsifiable predictions of the DNM. We show how the model simultaneously satisfies the conflicting desiderata of flexibility and falsifiability. Our key idea is that, while adjustable parameters are needed to accommodate the diversity across neurons, they must be fixed for a given individual neuron. This requirement introduces falsifiable constraints when this single neuron is probed with multiple stimuli. We also present mathematical analyses and simulation experiments that explicate some of these constraints.

Added: Sep 29, 2017
Article
Dubois J., Dehaene-Lambertz G., Kulikova S. et al. Neuroscience. 2015. Vol. 276. P. 48-71.

Studying how the healthy human brain develops is important to understand early pathological mechanisms and to assess the influence of fetal or perinatal events on later life. Brain development relies on complex and intermingled mechanisms especially during gestation and first post-natal months, with intense interactions between genetic, epigenetic and environmental factors. Although the baby's brain is organized early on, it is not a miniature adult brain: regional brain changes are asynchronous and protracted, i.e. sensory-motor regions develop early and quickly, whereas associative regions develop later and slowly over decades. Concurrently, the infant/child gradually achieves new performances, but how brain maturation relates to changes in behavior is poorly understood, requiring non-invasive in vivo imaging studies such as magnetic resonance imaging (MRI). Two main processes of early white matter development are reviewed: (1) establishment of connections between brain regions within functional networks, leading to adult-like organization during the last trimester of gestation, (2) maturation (myelination) of these connections during infancy to provide efficient transfers of information. Current knowledge from post-mortem descriptions and in vivo MRI studies is summed up, focusing on T1- and T2-weighted imaging, diffusion tensor imaging, and quantitative mapping of T1/T2 relaxation times, myelin water fraction and magnetization transfer ratio.

Added: Oct 22, 2015
Article
Blythe D., Haufe S., Müller K. et al. Neuroimage. 2014. Vol. 99. No. 1. P. 377-387.

Although the long-range temporal correlation (LRTC) of the amplitude fluctuations of neuronal EEG/MEG oscillations is widely acknowledged, the majority of studies to date have been performed in sensor space, disregarding the mixing effects implied by volume conduction and confounding noise. While the effect of mixing on the evaluation of evoked responses and connectivity measures has been extensively studied, there are, to date, no studies reporting on the differences in the values of the estimated Hurst exponents when moving between sensor and source space representations of the multivariate data or on the effect of noise. Such differences, if not duly acknowledged, may lead to erroneous data interpretations. We show in simulations and in theory that measuring Hurst exponents in sensor space may lead to an incomplete picture of the LRTC properties of the underlying data and that noise may significantly bias the estimate of the Hurst exponent of the underlying signal. Moreover, these predictions are confirmed in real data, where we analyze the amplitude dynamics of neuronal oscillations in the resting state from EEG data. By moving either to an independent components representation or to a source representation which maximizes the signal to noise ratio in the alpha frequency range, we observe greater variance, skewness and kurtosis over measured Hurst exponents than in sensor space. We confirm the suitability of conventional source separation methodology by introducing a novel algorithm HeMax which obtains a source maximizing the Hurst exponent in the amplitude dynamics of narrow band oscillations. Our findings imply that the long-range correlative properties of the EEG should be studied in source space, in such a way that the SNR is maximized, or at least with spatial decomposition techniques approximating source activities, rather than in sensor space.

Added: Feb 17, 2015
Article
Shchekotikhin A., Glazunova V.A., Dezhenkova L. et al. European Journal of Medicinal Chemistry. 2011. Vol. 46. No. 1. P. 423-428.

We developed the synthesis of a series of furan-fused tetracyclic analogues of the antitumor agent ametantrone. The reactions included nucleophilic substitution of propoxy groups in 4,11-dipropoxyanthra[2,3-b]furan-5,10-diones with ethylenediamines, producing the derivatives of 4,11-diaminoanthra[2,3-b] furan-5,10-dione in good yields. Studies of anti-proliferative activity on a panel of mammalian tumor cell lines demonstrated that anthra[2,3-b]furan-5,10- diones were the most potent derivatives among heteroarene-fused ametantrone analogues with one heteroatom. We identified several compounds that evoked a growth inhibitory effect at submicromolar concentrations. The anthra[2,3-b]furan-5,10-dione 9 with distal methylamino groups was markedly potent against drug-resistant cell lines with P-glycoprotein overexpression or p53 gene deletion. Furthermore, this derivative attenuated in vitro topoisomerase I-mediated DNA uncoiling at low micromolar concentrations. These results demonstrate that anthrafurandiones are a new class of heterocyclic anthraquinone derivatives with the properties potentially valuable for anticancer therapy.

 

 

Added: Jul 14, 2015