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The effect of substitution of lithium cations in the sublattice A of sodium bismuth titanate on the parameters of the crystal structure, microstructure, dielectric and local piezoelectric properties of ceramics [(Na0.5Bi0.5)1-xLix] TiO3 with x = 0 ÷ 0.1 has been studied. Modified samples have been characterized by phase transitions manifesting themselves in the form of peaks of permittivity near ∼600 K. An increase in the value of the piezoelectric coefficient d33 at x ≥ 0.08 has been established, which correlates with an increase in the value of dielectric permittivity at room temperature. [ABSTRACT FROM AUTHOR]

LiNbO3 thin films with a thickness of 200 nm were deposited onto Al2O3 substrate by RF-magnetron sputtering technique without intentional substrate heating. The results demonstrate that post-growth infrared pulsed light annealing of the amorphous LiNbO3 films leads to the formation of two phases, LiNbO3 and LiNb3O8. After annealing at temperatures of 700 to 800 °C, the percentage of the nonferroelectric phase LiNb3O8 was minimal. The surface composition of the films annealed at different temperatures was examined by X-ray photoelectron spectroscopy. Piezoresponse force microscopy was used to study both the vertical and the lateral polarization and to visualize the piezoelectric inactivity of LiNb3O8 grains. A comparison of the results of PFM and XPS measurements revealed that there is a correlation between the fraction of the piezoelectric phase and the film composition: At an annealing temperature higher than 850 °C, the atomic ratio of lithium to niobium decreases compared to the initial value along with a decrease of the fraction of the piezoelectric phase. [ABSTRACT FROM AUTHOR]

The article is aimed at developing a functional-structural model for evaluating the impact of digital technologies on the activities of enterprise taking into account the contour of economic policy implementation based on digital transformation. Intensifying the pace of digital transformation at all levels of the economic system, increasing competition in the domestic and foreign markets, limitedness of the traditional growth resources determine an actualization of the problems of ensuring a sustainable development of industrial-economic systems. Defining the factors of progressive development, the scholars are unanimous that the key to the economic growth of enterprise is the introduction of digital technologies. That is why the key condition of development of production-economical systems is management of investment into digitalization. Systematization and generalization of scientific developments of leading domestic and foreign scientists provided an opportunity to isolate directions of digital technologies development, advantages of their incorporation in the production-commercial activities of enterprise and provide the theoretical and instrumental basis for research problems of investment into the process of digitalization. The theoretical basis of the management of investment into digital transformations in the enterprise in the context of a comprehensive approach are the system economic theory and the integrated theory of IT-risk management. A contour of economic policy implementation on the basis of digital transformation is suggested, within its structure a characterization of the levels of implementation of digital technology is given from the standpoint of the architectonics of economy system. A functional-structural model for evaluating the impact of digital technologies on the activities of the enterprise depending on functions, digitalization effects and terms of the investment management is developed.

The article is aimed at forming a mechanism for risk management of construction projects, to provide researching within its terms of the possibility of attracting additional financial resources through compensatory financing on the basis of deferred tax payments (Tax Increment Financing – TIF). Studying the risk management practices in the field of construction has demonstrated the fragmentary nature of the existing system, but with the appropriate legal framework and in view of the experience of other countries, development of preventive measures can be a source of financial resources for the implementation of construction projects. According to the results of the carried out research on the financial compensatory technology of TIF, the authors present proposals as to the formation of a mechanism for risk management of construction projects, with allocation the following components in its structure: theoretical-methodological, organizational-economic, process-empirical.

In this work, we present a comprehensive analytical model and results for an absolute pH sensor. Our work aims to address critical scientific issues such as: (1) the impact of the oxide degradation (sensing interface deterioration) on the sensor’s performance and (2) how to achieve a measurement of the absolute ion activity. The methods described here are based on analytical equations which we have derived and implemented in MATLAB code to execute the numerical experiments. The main results of our work show that the depletion width of the sensors is strongly influenced by the pH and the variations of the same depletion width as a function of the pH is significantly smaller for hafnium dioxide in comparison to silicon dioxide. We propose a method to determine the absolute pH using a dual capacitance system, which can be mapped to unequivocally determine the acidity. We compare the impact of degradation in two materials: SiO2 and HfO2, and we illustrate the acidity determination with the functioning of a dual device with SiO2.

The paper considers modern methodological approaches of Russian and foreign authors to assess the investment attractiveness of the industry. The object of analysis is a new industry telemedicine. As a result of the study, industry specifics and factors affecting its investment attractiveness were identified. The work also explores methodological approaches to assessing investment attractiveness and investment efficiency. The uniqueness of the study consist in the fact that previously there were no works, approaches and methods analyzing investment attractiveness in terms of their applicability to the selected industry. Based on the results of a critical analysis of the proposed approaches and methods for assessing investment attractiveness, requirements were formed that need to be considered when developing and applying methodological approaches to assessing the investment attractiveness of telemedicine.

Currently the processes of digitalization have a strong impact on all spheres of society. Fundamental changes are observed in the economy due to digital expansion, implementing and usage of various modern technologies. The financial market as an essential part of the economy was the first thing that had to be digitalized. The Central Bank of the Russian Federation is actively engaged in the development of financial technologies in the financial market. Financial technologies can affect the availability of financial products and services, which in the future will contribute to sustainable development and increase the competitiveness of the entire financial sector. The Central Bank of the Russian Federation as a megaregulator monitors the financial market and currently a comprehensive system of relevant indicators is being formed. It is to assess the specifics of different profiles of the financial market, reflecting its most important characteristics, including the level of digitalization. It has been recognized to take a closer look at the description of such a concept as the digital profile of the financial market. To describe the entire financial market, we need comprehensive methodological approach that would reflect its characteristics. The research was conducted on the basis of studying the existing experience of analyzing the market of financial and technological services, its features, as well as methods and indicators for assessing the level of digitalization of the financial sector. The article proposed the concept of a digital profile of the financial market and developed a methodological approach for its analysis in order to implement the functions of the Central Bank of Russian Federation.

Single-phase ceramic samples of new compositions (Na1 –хSrх)0.5Bi0.5TiO3 (x = 0–0.5), including those modified by additives of SiO2 and ZnO oxides, have been obtained by solid-phase synthesis. The crystal structure and microstructure of these samples, as well as their dielectric, nonlinear optical, and local piezoelectric properties, have been studied. The formation of a perovskite-type phase with a pseudocubic unit cell in all synthesized samples and an increase in the cell volume as a result of partial substitution of perovskite structure cations are established. A decrease in the temperature of ferroelectric phase transitions (confirmed by the methods of dielectric spectroscopy and laser second-harmonic generation) to the tetragonal paraelectric phase is revealed. Remanent piezoelectric hysteresis loops are obtained for the synthesized samples in the polarization switching mode; this result confirms the occurrence of ferroelectric polarization switching. [ABSTRACT FROM AUTHOR]

The stems of Rubus idaeus L., a byproduct of the fruit-food industry, are known sources of bioactive compounds. The main objective of this study was to investigate the composition of polyphenolic compounds in R. idaeus stems. Seven cultivated raspberry varieties, thirteen garden samples, including five well-known raspberry varieties, and thirteen wild raspberry samples from different locations in Estonia were analyzed. The HPLC-MS method detected 62 substances, of which 42 were identified, 12 were tentatively identified, and 8 compounds remained unknown. Protocatechuic acid pentoside was dominant in most varieties and in all garden and wild raspberry samples. Dihydroxybenzoic acid hexoside 1, p -coumaroyl quinic acid 1, quercetin 4'-glucuronide, and p -coumaric acid glycoside were found in significant quantities. Correlations among the contents of individual compounds were established. When studying the dynamics of polyphenolic compound accumulation in, for example, the GR1 sample over a year, it was found that, in raspberry stems, the largest amount of them accumulated in April and slightly less in January and October. Investigating the dependence of the accumulation of polyphenols on the parts of the stem, it was found that the upper parts have the highest phenolic contents. Therefore, it is recommended to harvest approximately the upper third of the stem.

The prospect of creating a new medicine with psychotropic activity is shown as a result of studying the chemical composition and pharmacological activity of modified dry extracts of motherwort ( Leonurus cardiaca L.) tincture. The most promising substances were the dry extracts, modified by adding small amounts of arginine, valine, phenylalanine, glycine, lysine, and alanine. A total of 15 main phenolic substances were found in the extracts, and eight of them were identified. There were also 10 hydroxycinnamic acids in these extracts, three of which were identified (chlorogenic, caffeic, and rosmarinic acids). The dominant hydroxycinnamic acids were chlorogenic and caffeic acids. Among flavonoids, catechin, hyperoside, and rutin were identified. It should be noted that the extracts had a significant content of ellagic acid. On the basis of the results of the phytochemical analysis of the extracts, it can be concluded that the composition of phenolic compounds does not differ significantly, and the main differences are related to amino acids, which obviously have an impact on the overall pharmacological effect. The results obtained indicate the presence of anxiolytic activity in the motherwort extracts studied in complex with amino acids. The extracts with glycine, valine, and arginine were more effective in reducing anxiety in animals.

Extracts from aerial parts of G. aparine (cleavers) constitute a herbal remedy with monography in British Herbal Pharmacopeia. On the European market, there are several drugs and food supplements consisting of Galium extracts. In folk medicine, cleavers was used topically in Europe, Asia, and the Americas to treat skin diseases. In several remedies, cleavers is also listed as an immunomodulatory active herb influencing the defense response of the human body. The aim of this study was to investigate the immunostimulatory activity and antioxidant potential in vitro of a raw infusion of cleavers and bioactive fractions. The functional activity of lymphocytes in the reaction of the lymphocyte blast transformation (RLBT) method was used for immunomodulatory activity assays and direct scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and hydrogen peroxide (H 2 O 2 ) was chosen for the examination of antioxidant activity. It was shown that both the raw extract and fractions show significant immunostimulatory and scavenging activities. The obtained data partially justify the traditional use of cleavers as topical remedy for skin infections and for wounds.

Galium aparine L., family Rubiaceae, is a widely spread species in the Galium genus. The herb of G. aparine is part of folk remedies and dietary supplements. In this study, we analyzed the chemical composition and immunomodulatory activities of G. aparine herb ethanolic extracts obtained from the plant material by maceration with 20%, 60% or 96% ethanol. The contents of hydroxycinnamic acid derivatives, flavonoids and polyphenols were determined spectrophotometrically, with extractives and polysaccharides quantified gravimetrically. The qualitative composition was studied using UHPLC-DAD-MS/MS analysis; isolation not previously described in G. aparine quercetin rhamnoglucoside was carried out through column chromatography, and the immunomodulatory activity of extracts was determined in the reaction of lymphocyte blast transformation. Major constitutes of extracts were iridoids, i.e., monotropein, 10-desacetylasperulosidic acid and asperulosidic acid; p -hydroxybenzoic acid; hydroxycinnamic acid derivatives, i.e., 3- O -caffeoylquinic, 5- O -caffeoylquinic, 3,4- O -dicaffeoylquinic, 3,5- O -dicaffeoylquinic, 4,5-O-dicaffeoylquinic acids and caffeic acid derivatives; flavonoids, i.e., rutin, quercetin 3- O -rhamnoglucoside-7- O -glucoside, and isorhamnetin 3- O -glucorhamnoside. Significantly, quercetin 3- O -rhamnoglucoside-7- O -glucoside was first isolated and identified in Galium species so far investigated. All G. aparine herb ethanolic extracts stimulate the transformational activity of immunocompetent blood cells, with 96% ethanolic extract being the most active. The data obtained necessitate further research into the mechanisms of immunomodulatory activity of extracts from G. aparine herb.

The quantitative contents of 40 carboxylic acids, with the prevalence of hexadecanedioic, lignocerinic, behenic, azelaic, palmitic and benzoic acids, and 39 components of essential oil were determined in the extracts of the bark of Sorbus aucuparia by the GC-MS method. The quantitative contents of 6 phenolic compounds, i.e., chlorogenic, caffeic, and gallic acids, catechin, quercetin, and apigenin-7-glucoside were determined by the HPLC method in the ethanolic extract of the bark of Sorbus aucuparia. Key words: Sorbus aucuparia bark carboxylic acids phenolic compounds essential oil, GC-MS, HPLC.

A series of DNA primers containing nucleotides with various sugar pucker conformations at the 3'-terminus were chemically synthesized by solid-phase synthesis. The ability of wild-type (WT) HIV-1 reverse transcriptase (RT) and AZT-resistant (AZTr) RT to excise the 3'-terminal nucleotide was assessed. Nucleosides with a preference for the North conformation were more refractory to excision by both WT-RT and AZTr-RT. We found that DNA primers that contain North puckered-nucleotides at the 3'-terminus can also affect the translocation status of the RT/template/primer complex, which provides an underlying mechanism to avoid being excised. Together, these results point to a correlation between the sugar conformation of the 3'-terminal nucleotide, the precise position of HIV-1 RT on its nucleic acid substrate, and, in turn, its catalytic function. Nucleotide sugar conformation is therefore an important parameter in defining the susceptibility to RT-catalyzed phosphorolytic excision.

We report the synthesis, thermal stability, and RNase H substrate activity of 2'-deoxy-2',4'-difluoroarabino-modified nucleic acids. 2'-Deoxy-2',4'-difluoroarabinouridine (2,'4'-diF-araU) was prepared in a stereoselective way in six steps from 2'-deoxy-2'-fluoroarabinouridine (2'-F-araU). NMR analysis and quantum mechanical calculations at the nucleoside level reveal that introduction of 4'-fluorine introduces a strong bias toward the North conformation, despite the presence of the 2'-βF, which generally steers the sugar pucker toward the South/East conformation. Incorporation of the novel monomer into DNA results on a neutral to slightly stabilizing thermal effect on DNA-RNA hybrids. Insertion of 2',4'-diF-araU nucleotides in the DNA strand of a DNA-RNA hybrid decreases the rate of both human and HIV reverse transcriptase-associated RNase H-mediated cleavage of the complement RNA strand compared to that for an all-DNA strand or a DNA strand containing the corresponding 2'-F-araU nucleotide units, consistent with the notion that a 4'-fluorine in 2'-F-araU switches the preferred sugar conformation from DNA-like (South/East) to RNA-like (North).

Human immunodeficiency virus (HIV) encodes four essential enzymes: protease, integrase, reverse transcriptase (RT)-associated DNA polymerase, and RT-associated ribonuclease H (RNase H). Current clinically approved anti-AIDS drugs target all HIV enzymatic activities except RNase H, which has proven to be a very difficult target for HIV drug discovery. Our high-throughput screening activities identified the dihydroxycoumarin compound F3284-8495 as a specific inhibitor of RT RNase H, with low micromolar potency in vitro. Optimization of inhibitory potency can be facilitated by structural information about inhibitor-target binding. Here, we report the crystal structure of F3284-8495 bound to the active site of an isolated RNase H domain of HIV-1 RT at a resolution limit of 1.71Å. From predictions based on this structure, compounds were obtained that showed improved inhibitory activity. Computational analysis suggested structural alterations that could provide additional interactions with RT and thus improve inhibitory potency. These studies established proof of concept that F3284-8495 could be used as a favorable chemical scaffold for development of HIV RNase H inhibitors., (Copyright © 2014 Elsevier Ltd. All rights reserved.)