Stability and Radiation Damage of Protein Crystals as Studied by Means of Molecular Dynamics and Monte Carlo Simulation

Molecular Dynamics (MD) and Monte Carlo (MC) simulations of crystals can help in interpretation of experimental X-ray crystallography data. Particularly, they can be useful for understanding how various crystallization techniques affect protein conformational plasticity within the crystal lattice and the stability of biomolecular crystals. The latter has become especially important since the modern and extremely intense X-ray radiation sources (such as free electron lasers, FELs) appeared recently. In the present study we were able to show by means of computer simulations that the lysozyme crystals obtained using the Langmuir-Blodgett technique have an advantage over the classical ones (\u201cHanging Drop\u201d) in terms of their thermal stability as well as their stability against the radiation damage. We also demonstrate an important role of crystal water dynamics for stability of protein crystals

Live imaging of micro and macro wettability variations of carbonate oil reservoirs for enhanced oil recovery and CO/ trapping/storage

Carbonate hydrocarbon reservoirs are considered as potential candidates for chemically enhanced oil recovery and for CO² geological storage. However, investigation of one main controlling parameter—wettability—is usually performed by conventional integral methods at the core-scale. Moreover, literature reports show that wettability distribution may vary at the micro-scale due to the chemical heterogeneity of the reservoir and residing fluids. These differences may profoundly affect the derivation of other reservoir parameters such as relative permeability and capillary pressure, thus rendering subsequent simulations inaccurate. Here we developed an innovative approach by comparing the wettability distribution on carbonates at micro and macro-scale by combining live-imaging of controlled condensation experiments and X-ray mapping with sessile drop technique. The wettability was quantified by measuring the differences in contact angles before and after aging in palmitic, stearic and naphthenic acids. Furthermore, the influence of organic acids on wettability was examined at micro-scale, which revealed wetting heterogeneity of the surface (i.e., mixed wettability), while corresponding macro-scale measurements indicated hydrophobic wetting properties. The thickness of the adsorbed acid layer was determined, and it was correlated with the wetting properties. These findings bring into question the applicability of macro-scale data in reservoir modeling for enhanced oil recovery and geological storage of greenhouse gases

Enhancement of keV X-rays from low-density cellulose triacetate (TAC) foam targets

The interaction of a high-power laser with a low-density foam target can in some instances result in a significant enhancement in x-ray generation relative to that when the same laser is incident upon a homogenous solid. In this paper, we present x-ray emission studies from foam targets where the density is varied from under-dense to over-dense. The targets are irradiated with the first harmonic of Nd:Glass laser. The laser intensity on the target was approximately 2 × 1014 W/cm2 with the pulse duration of 500 ps. Mass-matched cellulose triacetate foam targets with densities of 2 mg/cc, 4 mg/cc, 7 mg/cc, and 20 mg/cc were used. The areal density presented by the targets on the laser beam axis was held constant at 0.2 mg/cm2 by varying the target thickness in inverse proportion to the density. The x-ray yield in the spectral range (5-8 keV) and (4.5-16 keV) was found to be enhanced by approximately 2.3 times in foam targets with the density of 2 mg/cc (under-dense) compared with foam targets with the density of 20 mg/cc (over-dense)

A Lithium Experiment in the Program of Solar Neutrino Research

The experiments sensitive to pp-neutrinos from the Sun are very perspective for the precise measurement of a mixing angle $\theta_{12}$. A $\nu$e$^{-}$ scattering experiment (Xmass) and/or a charged-current experiment (the indium detector) can measure the flux of electron pp-neutrinos. One can find the total flux of pp-neutrinos from a luminosity constraint after the contribution of $^7$Be and CNO neutrinos to the total luminosity of the Sun are measured. The radiochemical experiment utilizing a lithium target has the high sensitivity to the CNO neutrinos, thus, it has a good promise for the precise measurement of a mixing angle and for the test of a current theory of the evolution of the stars.Comment: 6 pages, 2 figures, 1 table, A report made by A.Kopylov at International Conference NANP-2005, June 2005, Dubna, Russi

The Interaction of Plasma Sialylated and Desialylated Lipoproteins with Collagen from the Intima and Media of Uninvolved and Atherosclerotic Human Aorta

We have evaluated the binding of sialylated and desialylated lipoproteins to collagen isolated from the proteoglycan and musculoelastic layers of intima and media of uninvolved human aorta and atherosclerotic lesions. Comparing various collagen preparations from the uninvolved intima-media, the binding of sialylated apoB-containing lipoproteins was best to collagen from the intimal PG-rich layer. Binding of sialylated apoB-containing lipoproteins to collagen from this layer of fatty streak and fibroatheroma was 1.4- and 3.1-fold lower, respectively, in comparison with normal intima. Desialylated VLDL versus sialylated one exhibited a greater binding (1.4- to 3.0-fold) to all the collagen preparations examined. Desialylated IDL and LDL showed a higher binding than sialylated ones when collagen from the intimal layers of fibroatheroma was used. Binding of desialylated HDL to collagen from the intimal PG-rich layer of normal tissue, initial lesion, and fatty streak was 1.2- to 2.0-fold higher compared with sialylated HDL

Альтернативность в архитектурном проектировании мостов и путепроводов

Modern extensive foreign and domestic experience in design and construction of multifunctional overpasses and bridges indicates that they have become an integral part of urbanised systems. They are endowed with the functions of important urban objects, and with their appearance they have won the right to be considered iconic structures. The subject of the article refers to architectural design of bridges and overpasses. The authors set themselves the task of considering the aspects of combining the main functional characteristics with the aesthetic properties of the object, designating visual components of the project and the specifics of alternativeness of design.The objective of the work is to consider alternativeness in architectural design of bridges and overpasses. A complex method, combining an analysis of the historical and modern experience of architectural theory and design practices, was based on technical literary materials. The study resulted in formulating indicators and leading principles of alternative design.The use of alternatives in the process of designing urban bridges and overpasses allows not only to consider functionality and economic feasibility of a particular project and construction of an object, but also its architectural and artistic orientation, aesthetic component, as well as the designer’s worldview and current trends in architecture. In the process of alternative design of bridges and overpasses, it is required to reproduce the overall complete image of the future structure, consider all kinds of details in structures and shape, and various criteria for layout and location in the environment.Современный обширный зарубежный и отечественный опыт проектирования и строительства многофункциональных путепроводов и мостов свидетельствует о том, что они стали неотъемлемой частью урбанизированных систем. Их наделяют функциями важных городских объектов, а своим обликом они завоевали право считаться знаковыми сооружениями. Предметом статьи является архитектурное проектирование мостов и путепроводов. Авторы в качестве задачи ставили перед собой рассмотрение аспектов объединения основных функциональных характеристик с эстетическими свойствами объекта, обозначение визуальных составляющих проекта и специфику вариантного проектирования.Цель работы – рассмотреть альтернативность в вопросах архитектурного проектирования мостов и путепроводов. Использован комплексный метод, включающий анализ исторического и современного опыта архитектурной теории и проектной практики на основе специализированных литературных материалов. В результате исследования сформулированы показатели и ведущие принципы альтернативного проектирования.Использование альтернативности в процессе проектирования городских мостов и путепроводов позволяет не только учитывать функционал и экономическую целесообразность конкретного проекта и строительства объекта, но и его архитектурно-художественную направленность, эстетический компонент, а также мировоззрение проектировщика и современные тенденции в сфере архитектуры. В процессе альтернативного проектирования мостов и путепроводов требуется воспроизводить общий полный образ будущего сооружения, принимать во внимание всевозможные детали в конструкциях и форме, учитывать различные критерии по компоновке и расположению в окружающей среде

Antimicrobial Resistance: A Risk Factor for the Biosafety System

Scientific relevance. In recent years, antimicrobial resistance in pathogenic microorganisms has become a global problem that threatens the health of humans and animals and poses a risk to the biosafety of Russia.Aim. The study aimed to analyse the prevalence of antimicrobial resistance, consider the risks and medical consequences of this biological phenomenon, and suggest ways to optimise the use of existing antimicrobial agents and search for new ones.Discussion. The emergence of antibiotic resistance in bacteria is a natural biological process; the selection of resistant microorganisms occurs constantly with the use of the entire spectrum of antimicrobial agents in healthcare, agriculture, and other fields. The World Health Organisation (WHO) monitors these processes using the Global Antimicrobial Resistance Surveillance System (GLASS). Russia has adopted the Strategy to prevent the spread of antimicrobial resistance in the Russian Federation to 2030. The country has established a regulatory framework that supports the operation of the national antimicrobial resistance prevention system. The strategy to prevent the spread of antimicrobial resistance is being implemented through making organisational arrangements and developing novel medicines with mechanisms of action based on an understanding of the molecular mechanisms of infection and resistance. This review considers the main approaches to designing exploratory studies and evaluating the antimicrobial activity of the innovative molecules obtained. The rapid development of synthetic biology increases the likelihood of creating synthetic biological pathogens with high virulence and resistance to antimicrobial agents, which might pose risks of artificial epidemics.Conclusions. The antimicrobial resistance prevention system in Russia should be considered a strategically essential medical technology ensuring the biosafety of the country and the people