Search

In this study, we report the development of efficient synthetic strategies for the preparation of novel 2'-carboxyl isoflavones and their recyclization products, pyrazoles and oxazoles. Utilizing readily accessible starting materials and mild reaction conditions, the synthesis affords valuable compounds with good to excellent yields. The presence of diverse functional groups, including hydroxyl, carboxyl, and carboxamido moieties, renders these molecules attractive for biological screening and targeted structural modifications. This work unveils new avenues for the design of compounds exhibiting a wide range of beneficial properties and opens new opportunities for future research into intramolecular interactions of proximal functional groups. [ABSTRACT FROM AUTHOR]

The interaction of 7-hydroxyneoflavone-6-enamino ketone with 8-dialkylamino-7-hydroxy-3-hetarylbenzopyran-2- and 4-ones led to the formation of 10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]-chromen-2,6-dione, which incorporated coumarin or chromone fragments at C-7 using a methylene linker. The recyclization of 7-[3-(1,3-benzothiazol-2-yl)-7-hydroxy-2-oxo-2H-8-chromenylmethyl]-10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]chromene-2,6-dione and 7-[6-ethyl-7-hydroxy-3-(4-methyl-1,3-thiazol-2-yl)-4-oxo-4H-8-chromenylmethyl]-10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]chromene-2,6-dione was investigated under the influence of N,N- and N,O-binucleophiles. [ABSTRACT FROM AUTHOR]

We studied the effect of long-term constant light exposure on the severity and reversibility of morphological changes in the liver of laboratory rats. Modeling of light exposure was carried out by means of 24 h exposure to artificial light (in the daytime—300 lk, at night—500 lk). During the study we found that morphological changes in the liver were represented by damage to the parenchyma and circulatory disorders, the degree of which increased with increasing duration of exposure. After providing natural light in the laboratory, gradual recovery of the morphological structure of the organ was observed, which indicates the reversibility of the changes detected. [ABSTRACT FROM AUTHOR]

Microorganisms of the genus Bacillus were shown to have different effects on the degradation of polylactide packaging material. The degradation experiment was carried out on an agar medium at a temperature of 55°C and pH 5.9 for 14 days. This is the first report on the abiotic hydrolysis significantly slowing down during incubation with B. licheniformis S8 and occurring in parallel with the main process, enzymatic hydrolysis. The latter involved sequential cleavage of monomer units from the end of the macromolecule and the formation of low molecular weight products used by microorganisms as a substrate; it contributed to a decrease in the mass of polylactide by 5.1%, while maintaining its molecular weight and decreasing the molecular-weight dispersity. In the presence of bacteria B. amyloliquefaciens, B. subtilis subsp. spizizenii, and B. subtilis subsp. inaquosorum, the mass of polymer sample did not decrease, but the molecular weight decreased significantly, similar to abiotic hydrolysis. [ABSTRACT FROM AUTHOR]

This research focuses on the synthesis and in vitro anticancer evaluation of functionalized 2-aryl-5-(4-piperazin-1-yl)oxazoles and 5-[(4-arylsulfonyl) piperazin-1-yl]-2-phenyloxazoles. Oxazoles are a versatile class of compounds with diverse biological activities, making them attractive targets in medicinal chemistry. We incorporated amino and sulfonamide functionalities into the oxazole scaffold, as they have shown potential for interacting with biological targets. The synthesis of target oxazole derivatives was accomplished using 2-aroylamino-3,3-dichloroacrylonitriles as starting materials and employing efficient reaction conditions. The resulting compounds exhibited structural features that make them promising candidates for further chemical modifications and biological evaluations. Additionally, a series of sulfonamides were synthesized from 5-(piperazin-1-yl)oxazole-4-carbonitrile hydrochloride, offering diverse bioactivity and versatile structural characteristics. However, no potent inhibitors of malignant cell growth were identified among the tested compounds. Nevertheless, we categorized the investigated substances into two distinct groups based on their activity profile. Group A, comprising sulfonamides, displayed pronounced anticancer activity against breast cancer and melanoma cell lines. On the other hand, group B, the 2-aryl-5-(4-R-piperazin-1-yl)oxazole-4-carbonitriles, exhibited a moderate effect primarily on renal cancer cell lines. These findings provide valuable insights for further structural modifications in the quest for more potent anticancer agents. [ABSTRACT FROM AUTHOR]

Influence of light exposure duration (model 18 : 6) on hormonal indices of stress-implementing system in laboratory animals blood is studied. Activity of stress systems central link was evaluated based on data on concentration of adrenocorticotrophic hormone, melatonin and β-endorphin in blood serum, observed during enzyme immunoassay. Reaction of peripheric link of the stress-implementing system was evaluated in blood smears based on results of qualitative count of catecholamine granules in erythrocytes. It was established, that variations of hormonal indices of the stress systems for laboratory animals depend on trigger factor activity periods. With increase of the experiment duration to 21st days the most pronounced reduction of melatonin, β-endorphin and increase of adrenocorticotrophic hormone concentration, as well as sharp increase of catecholamines level are observed in the blood serum. These hormonal changes develop as a result of failure of compensation mechanisms of the stress-implementing systems in connection with melatonin rhythms disturbance, that indicates the gradual development of the general adaptation syndrome. [ABSTRACT FROM AUTHOR]

An approach to the preparation of hereto unknown parent 5- and 7-azachromones was developed. The key step relied on the NaHmediated condensation of isomeric 2(4)-acetyl-3-hydroxypyridines (obtained from isomeric 3-hydroxypyridine carboxylic acids) with ethyl formate. Physicochemical studies revealed that no significant changes in lipophilicity and slightly higher basicity values were observed upon introduction of the nitrogen atom into the parent chromone; therefore, 5- and 7-azachromones can be used as direct analogs of this classical heterocyclic fragment. The synthetic utility of azachromones was demonstrated by the preparation of a series of 3,4-dihydro-2H-pyrano[3,2-b]pyridines and -[2,3-c]pyridines. The catalytic hydrogenation of the pyranone ring of azachromones was performed for the selective preparation of isomeric azachromanols, which could be oxidized with MnO2 (to azachromanones) or involved into Barton–McCombie deoxygenation (for the synthesis of the non-substituted derivatives). [ABSTRACT FROM AUTHOR]

Feasible, scalable, and cost-effective method for the synthesis of low-molecular 2-(trifluoroacetyl)oxazoles from the corresponding oxazoles and trifluoroacetic anhydride was elaborated. The procedure was scaled up to 70 g of the desired ketones in a single run. Tolerance of the oxazole core to various functional group transformations was demonstrated. Thus, synthesis of various building blocks approved the possibility of using 2-(trifluoroacetyl)oxazoles as a starting materials for medicinal chemistry. [ABSTRACT FROM AUTHOR]

This microreview provides a comprehensive analysis of synthetic approaches to chromeno[2,3-c]pyrrol-9(2H)-ones, a promising class of compounds that incorporate chromene and pyrrole frameworks. Starting from their earliest mentions and encompassing the latest advancements, this review categorizes the synthetic methods based on the structure of the starting materials. [ABSTRACT FROM AUTHOR]

Effect of the structural mechanical modification via the crazing mechanism and composition of films based on HDPE nanocomposites and highly dispersed silica particles on the thermo-oxidative degradation and pyrolysis is studied. The incorporation of highly dispersed silica particles into the polymer matrix causes a reduction in the onset temperature of the intense weight loss of the composites by about 30°С and an increase in the temperature interval by 100°С under conditions of thermo-oxidative degradation. It is shown that in pyrolytic decomposition the HDPE‒SiO2 composite also starts to lose weight at lower temperatures (smaller by 50°С). Using various kinetic approaches to process the TGA curves the activation energy for each stage of thermal oxidation and pyrolysis is determined for structurally different HDPE-based samples. In the case of thermo-oxidative degradation, dependence of the activation energy on conversion is shown to be complex, thereby reflecting the multistage nature of the process. In pyrolysis, the activation energy is almost constant at all stages of the process. For various models of the processes, the activation energy is calculated by the Coats–Redfern method and the most probable mechanisms of thermal degradation and pyrolysis of the samples are proposed. [ABSTRACT FROM AUTHOR]

A nanocomposite based on high-density polyethylene with 13–15 wt % of barium titanate was obtained by the low-temperature synthesis of the inorganic component directly in the mesopores of an oriented polymer matrix using the sol-gel method followed by hydrothermal treatment in an alkaline medium. Crystallization of barium titanate in nanopores was detected by X-ray powder diffraction and electron microscopy to occur mainly in a cubic crystalline modification with an average crystallite size of 16 nm, where crystallites form chain structures. The dielectric properties of the polymer nanocomposite and barium titanate synthesized under similar conditions were comparatively assessed. [ABSTRACT FROM AUTHOR]

Using the methods of scanning and transmission electron microscopy, the microstructure of a gradient material "Fe-18Cr-10Ni-Ti-0.08C steel / 80Ni-20Cr alloy" (wt.%) produced by the double-wire electron-beam additive manufacturing is studied. The chemical composition of the material continuously changes from the one corresponding to the Fe-18Cr-10Ni-Ti-0.08C stainless steel to that of the 80Ni-20Cr alloy, with the intermediate gradient layer formed by deposition of two wires in different ratios. The microstructure of the part of the samples, which corresponds to pure steel without any addition of the NiCr alloy, is characterized by large columnar austenitic grains (γ-phase) with a small fraction of dendritic δ-ferrite (about 20%). An addition of the NiCr alloy suppresses the formation of the δ-phase during the steel additive growth, thus the main part of the gradient sample has an austenitic coarse-grained structure. In the part of the material, containing a high fraction of the NiCr alloy, particles of intermetallic phases are formed. Stabilization of the austenitic structure of the stainless steel with an addition of the NiCr alloy is discussed in terms of changing the chromium-nickel equivalent and the mechanism of crystallization in the melting pool during the additive manufacture. [ABSTRACT FROM AUTHOR]

The methylenebisflavonoids 7-hydroxy-3-hetaryl-8-(4-oxo-4H-3-chromenylmethyl)-4H-4-chromenones and 7-hydroxy-3-hetaryl-8-(4-oxo-4H-3-chromenylmethyl)-2H-2-chromenones were synthesized via the reaction of 7-hydroxy-8-dialkylaminomethyl-3-hetarylcoumarins and chromones with 3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one. Recyclization of 3-(1,3-benzthiazol-2-yl)-7-hydroxy-8-(4-oxo-4H-3-chromenylmethyl)-2H-2-chromenone through the action of N,N- and N,O-binucleophiles produced new 3-benzthiazolylcoumarin derivatives modified by pyrazole, isoxazole, and pyrimidine heterocycles. [ABSTRACT FROM AUTHOR]

An efficient and practical synthetic procedure for libraries of diversified 1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones using a multicomponent process is presented. A convenient synthetic procedure for obtaining functionalized 3-(2-hydroxyphenyl)-4,5-dihydropyrrolo[3,4-c]pyrazol-6(1H)-ones via ring-opening strategy has also been developed. This protocol was found to be compatible with a wide range of substituents and paves the way for the practical synthesis of title compounds with a broad range of substituents under mild condition. The products can be easily isolated by crystallization without the use of chromatography. [ABSTRACT FROM AUTHOR]

Furo[3,2-g]neoflavones and furo[2,3-h]neoflavones modified by coumarin and (het)aroyl substituents were synthesized via reactions of 7-hydroxy-6(8)-acetyl(formyl)neoflavones with substituted phenacyl bromides, 2-bromacetylbenzofuran, and 4-chloromethylcoumarins. [ABSTRACT FROM AUTHOR]

The phase composition, plastic deformation and fracture micromechanisms of Fe–(25–26)Cr–(5–12)Mn–0.15C–0.55N (wt.%) high-nitrogen chromium-manganese steel, manufactured by electron-beam 3D-printing (additive manufacturing) and subjected to heat treatment (at a temperature of 1150°C followed by quenching), are studied. In order to identify the effect of the electron-beam 3D-printing process on the phase composition, microstructure and mechanical properties of high-nitrogen steel, the data obtained are compared with those for Fe–21Cr–22Mn–0.15C–0.53N austenitic steel (wt.%) formed by traditional methods (casting and heat treatment) and used as a material for additive manufacturing. It is experimentally observed that in the specimens formed by additive manufacturing, the depletion of the steel composition in manganese during the electron-beam 3D-printing and post-built heat treatment contributes to the formation of a macro- and microscopically inhomogeneous two-phase structure. The steel specimens contain irregularly shaped macroscopic regions with large ferrite grains or with a two-phase austenite-ferrite structure (microscopic inhomogeneity). Despite the change in the concentration of the basic elements (chromium and manganese) in additive manufacturing, there remains a high concentration of interstitial atoms (nitrogen and carbon). This contributes to a macroscopically heterogeneous distribution of interstitial atoms in the specimens – the formation of a supersaturated interstitial solid solution in the austenitic regions due to the low solubility of nitrogen and carbon in the ferrite regions. This inhomogeneous heterophase (ferrite-austenite) structure exhibits high strength properties, good ductility and work hardening, which are close to those of the specimens of the initial high-nitrogen austenitic steel used as the raw material for additive manufacturing. [ABSTRACT FROM AUTHOR]

Polylactide-based materials are often considered an alternative to materials produced from traditionally hardly degradable polymers. Porous polylactide membranes, matrices, and scaffolds are especially attractive for use in biomedicine. The review concerns the physicochemical basis and structural and morphological opportunities of various methods for the manufacture of porous polylactide, such as sintering, 3D printing, electrospinning, foaming, etching, and the processes of phase separation and orientational drawing. Special attention is focused on the effect of porous structure parameters on the rate of hydrolytic degradation of the polymer and the prospects for the development of application areas of similar porous materials. [ABSTRACT FROM AUTHOR]

We studied the formation of the reparative regenerate of the skin wound in rats under the effect of drug products based on keratan and secretome of bone marrow mesenchymal stem cells (MSC), as well as bone marrow cells (native and exposed to laser radiation with a wavelength of 1.56 μm). Due to the biological affinity for the dermal tissue, keratan preparations being applied to the skin stimulate regeneration of the wound defect. This substance in the form of a gel is characterized by high diffusion capacity, penetrates into the deeper layers of the dermis, and promotes the growth of the granulation tissue. Application of an ointment prepared on the basis of MSC secretome promotes quick transition of the healing process from the inflammatory to the regenerative stage. Thus, bone marrow cells were successfully used for skin wound healing. The results of the use of bone marrow cells for the healing of skin wounds were successful; bone marrow exposed to laser radiation demonstrated high efficiency in promoting reparative processes. [ABSTRACT FROM AUTHOR]

Approaches to the synthesis of isocoumarins and 3,4-dihydroisocoumarins containing natural or synthetic amino-acid fragments are reviewed. Most attention is paid to the two most numerous groups of natural 3,4-dihydroisocoumarins, i.e., ochratoxins and amicoumacins. [ABSTRACT FROM AUTHOR]

This review analyzes immunological impairments in Parkinson's disease (PD). We present data on neuroinflammation, with which cell degeneration in the substantia nigra of the brain is associated and in which innate and adaptive immune system cells are involved. Brain, cerebrospinal fluid, and peripheral blood cytokine levels are analyzed. The interaction between neuroinflammation and neuron dysfunction is considered. Data on immunological impairments in people with PD and animals with models of this disease are presented. The characteristics of models of PD are discussed. Data on impairments to the blood–brain barrier are presented, along with evidence for the occurrence of autoimmune inflammation in this disease. We discuss the question of preclinical markers of PD, including immunological, i.e., cytokines, HLA-DR and HLA-DQ antigens, autoantibodies, etc. The creation of algorithms for the presymptomatic diagnosis of PD and its prophylaxis and treatment at the presymptomatic stage will lead to the cessation or slowing of neuron death. [ABSTRACT FROM AUTHOR]

The features of crack formation near the fracture region and the fracture micromechanism are investigated during uniaxial tension of specimens of Ni–Cr stainless steels, Fe–19Cr–9Ni–0.1C and Fe–19Cr–9Ni–1.4Nb–0.1C, produced by the method of 3D wire-feed electron beam additive manufacturing (EBAM) as a function of the phase composition and phase distribution in the structure. It is found out that in the specimens with a twophase (austenite/δ-ferrite) microstructure the ferrite morphology and its volume content (up 25%) affect the plastic shear distribution in austenite and ferrite and exert a slight influence on the formation of strain localization micro- and macrobands in the pre-fracture stage, and the crack-formation mechanism is similar to that observed in cast stainless steels of similar compositions, which possess single-phase austenitic structure. In additively-manufactured steel containing niobium the formation of brittle niobium- and iron-based intermetallic phases favors the formation of pores and microcracks at the austenite/NbFeCrNi-phase or the δ- ferrite/NbFeCrNi-phase interfaces, while the processes of cracking in the strain localization bands (and their formation) turn out to be suppressed. Irrespective of the elemental and phase compositions of steel specimensformed by the method of 3D additive manufacturing, the principal micromechanism of their fracture, transgranular dimple fracture, is similar to that observed in the cast specimens of austenitic stainless steels. [ABSTRACT FROM AUTHOR]

The use of boron for microalloying structural steels allowed increasing the strength characteristics of fasteners produced under the JSC BelZAN conditions. Boron-containing steels serve as an effective replacement for medium-carbon and alloy steels 35, 45, 40Kh, 40KhN, and 38KhGNM. [ABSTRACT FROM AUTHOR]

A methodology for synthesizing amino-acid derivatives of pyranocoumarins in three steps using pyranocoumarin oximes as starting compounds was developed. A series of pyranocoumarins containing the amino acids glycine, alanine, phenylalanine, methionine, leucine, and β-alanine in their structures could be prepared using the activated ester method. [ABSTRACT FROM AUTHOR]

An alternative method for production of hybrid organic–inorganic nanocomposites based on porous polyolefin films (isotactic polypropylene, high density polyethylene), deformed via crazing mechanism in physically active media, and calcium phosphates is proposed. Film composite materials of different structure and containing 10–25 wt % of filler are obtained. Particles of calcium hydroxyapatite with a diameter of 15–50 nm are formed in these films at once in the pores of the polymer matrices with the development of a layer, the morphology of which is determined by the structure of the original porous films, and its parameters can be controlled by the reaction conditions. It is found that the composites obtained are characterized by anisotropy of mechanical properties, and the introduction of the calcium phosphate particles results in some increase in the mechanical characteristics of the polymer matrices. High-temperature heating (up to 700°C) of nanocomposites leads to burning out of the polymer matrix and formation of porous calcium hydroxyapatite residues consisting of nanoparticles with different morphology depending on the initial porous structure of polymer (from needle-shaped crystals with a length of 100–150 nm and about 10 nm in diameter to spheres with a diameter of 50–90 nm). The results obtained are relevant for the directional regulation of the structure and properties of bioactive substances and creation of modern materials for biomedical use. [ABSTRACT FROM AUTHOR]

A convenient method was developed for the synthesis of novel isoquinolin-1(2H)-ones, 1-chloroisoquinolines, and 1-aminoisoquinolines with a heterocyclic substituent in position 3 via a recyclization of 3-hetarylisocoumarins with (NH4)2CO3. 1-Aminoisoquinolines were efficiently obtained from corresponding 1-chloro-3-hetarylisoquinolines (obtained by interaction of isoquinolin-1(2H)-ones with POCl3) and cyclic secondary amines (morpholine or 1-methylpiperazine). Literature data and preliminary results of biological assays allow to consider 1-amino-3-hetarylisoquinolines a promising family of anticancer compounds. [ABSTRACT FROM AUTHOR]

A billet of an AISI 304-type austenitic stainless steel has been built using a wire-feed electron beam additive manufacturing (EBAM) in a layer-by-layer strategy. A microstructure, grain boundary assemble, phase composition and tensile properties of steel billet have been investigated in as-built specimens and after post-built solid-solution treatment. As-built austenitic stainless steel is a highly anisotropic heterophase material with high fraction of interphase boundaries (austenite/ferrite) and intergranular boundaries (austenite/austenite). A macroscopically inhomogeneous (layered) structure with columnar austenitic grain growth has been produced during EBAM processing. The coarse-grained austenitic structure contains δ-ferrite of dendritic morphology in as-built specimens. Ductility and strength properties of the additively manufactured steel show substantial anisotropy, which is strongly correlated with macro- and microstructural peculiarities of the as-built billet. Post-built solid-solution treatment decreases a volume fraction of ferrite in the microstructure, changes the morphology of ferrite phase and, therefore, varies the distribution of interphase boundaries (ferrite/austenite). The effect of post-built solid-solution treatment on tensile properties of the EBAM manufactured steel is discussed taking into account a change in microstructure and phase composition, grain and phase boundary distribution in the specimens. [ABSTRACT FROM AUTHOR]

This paper describes the results of an investigation into a microstructure formation on a wire-feed electron beam additive manufactured "steel–copper" bimetallic sample. The peculiarities of a gradient zone structure with a smooth change of components' concentration are revealed. The heterogeneity of copper and steel distribution in the gradient zone is provided by copper solidification and precipitation mechanisms. Both solidification of coarse copper inclusions in the interdendrite areas or along the dendrite boundaries and precipitation of fine Cu-based particles at the cooling stage from the solid solution of Cu in γ-Fe are the main factors of structure formation during the double wire gradient zone deposition. The presence of such fine copper precipitates from the supersaturated solid solution was revealed by means of transmission electron microscopy. The shape of copper particles in the gradient zone varies from spherical to oblong and irregular. The shape of steel particles and/or grains is mainly determined by the peculiarities of the crystallization zone and is characterized by the primary crystallization of γ-iron dendrites from the liquid melt. A physical scheme describing a variation in phase composition and microstructure in gradient zone of the bimetallic specimen was proposed. [ABSTRACT FROM AUTHOR]

Systematic investigations of uniaxial deformation of an amorphous isotropic polylactide film in water-ethanol solutions of different composition are carried out and optimal conditions for polymer deformation by the crazing mechanism are determined. In the whole range of the solution compositions, the polylactide deformation is accompanied by the formation of a highly dispersed fibrillar-porous structure according to the mechanism of classical crazing. When the ethanol content is ~35 wt %, the film deformability increases sharply, and it reaches 400-500% in solutions with the ethanol content of more than 45 wt %. The fine structure of the polylactide crazes during deformation in a 50% aqueous ethanol solution is studied in situ by X-ray scattering at small angles. The intensity distribution curves for polylactide samples, regardless of the degree of deformation, are characterized by the presence of an interference maximum, which indicates the regular arrangement of the individual fibrils in crazes relative to each other. The interfibrillar distance is 40 nm at the degree of deformation up to 200%. Composite materials containing nanoparticles (average crystallite size is ~30 nm) of various biologically active calcium phosphates are obtained on the basis of porous polylactide matrices (with a volumetric porosity of ~45 vol %) using the method of countercurrent diffusion between aqueous solutions of calcium nitrate and ammonium hydrogen phosphate. The filler content has reached 30 wt %. Such organomineral materials are considered promising in the field of biomedicine. [ABSTRACT FROM AUTHOR]

The effect of a finely divided structure created via the mechanism of delocalized crazing on the processes of thermo-oxidative degradation of isotactic polypropylene has been studied. It has been shown that the thermal stability of porous films is reduced at relatively low temperatures (up to 155°C) and they become brittle. In contrast, their degradation rate at temperatures above 400°C is two times below that for the original, nonporous films because of the formation of crosslinked network structures and carbonization. The formation of titania and silica nanoparticles via hydrolytic decomposition of the respective alkoxides directly in the pore space of the polypropylene matrix substantially alters its thermal stability, depending on the precursor concentration, the extent of hydrolysis, and the composite structure. The greatest increases in the mass-loss-onset temperature and the temperature of the maximum mass-loss rate (by 80-100°C) have been observed for the composites with 40 wt % titanium dioxide. It has been assumed that the enhancement of thermal stability is due to the significant concentration of the products of incomplete hydrolysis of titanium alkoxy derivatives. The silica particles, in contrast, exert a signification influence on the thermo-oxidative-degradation processes in polypropylene at their low concentration (up to 5 wt %), a result that is associated with the structural features of such composites. [ABSTRACT FROM AUTHOR]

The surface composition of two samples synthesized by the combined carbonization of poly(vinylidene fluoride) (PVDF) films is studied by X-ray photoelectron spectroscopy. One of them is successively exposed only to chemical and radiation impacts, and the treatment of the other includes chemical, heat, and radiation exposure. The chemical preparation of both samples is the same. It is shown that the magnitude and direction of the gradient of the residual fluorine concentration in the surface layer of PVDF carbonization products can be controlled. Since dehydrofluorination decreases the surface electrical resistance of the material, a combination of chemical, heat, and radiation treatments can be used to create a predetermined sequence of heterolayers with different fluorine concentration on a flexible and transparent polymer base and, therefore, with different conductivities. [ABSTRACT FROM AUTHOR]

Nonprofit organizations in Russia are introducing for-profit activities as a means of gaining autonomy from external donors, and as instruments of strategic planning and sustainable development. This study focuses on organizations that work with welfare provision and explores how they reconcile entrepreneurial activities with their social mission. More specifically, we interrogate how two institutional logics, business and nonprofit, are defined and reconciled in organizational identities, structures and hierarchies. Socially oriented nonprofits define their mission through service to beneficiaries, through personal and professional dedication to beneficiaries’ well-being, and through making an impact on public policies and the society at large. They mimic a business approach in strategic planning and meticulous reporting, but subordinate profit-seeking to social mission by integrating entrepreneurial activities into already existing organizational structures, or by separating them into independent entities. [ABSTRACT FROM AUTHOR]

The interpretation of the nature and parameters of the source for the earthquake that occurred in Sumatra on December 26, 2004 is suggested. Our study relies on a variety of data on the geological structure of the region, long-term seismicity, spatial distribution of the foreshocks and aftershocks, and focal mechanisms; and the pattern of shaking and tsunami, regularities in the occurrence of the earthquakes, and the genetic relationship between the seismic and geological parameters inherent in various types of seismogenic zones including island arcs. The source of the Sumatran earthquake is a steep reverse fault striking parallel to the island arc and dipping towards the ocean. The length of the fault is ∼450 km, and its probable bedding depth is ∼70-100 km. The magnitude of this seismic event corresponding to the length of its source is 8.9-9.0. The vertical displacement in the source probably reached 9-13 m. The fault is located near the inner boundary of the Aceh Depression between the epicenter of the earthquake and the northern tip of the depression. The strike-slip and strike-slip reverse the faults cutting the island arc form the northern and southern borders of the source. The location and source parameters in the suggested interpretation account quite well for the observed pattern of shaking and tsunami. The Aceh Depression and its environs probably also host other seismic sources in the form of large reverse faults. The Sumatran earthquake, which was the culmination of the seismogenic activation of the Andaman-Sumatra island arc in the beginning of XXI century, is a typical tsunamigenic island-arc earthquake. By its characteristics, this event is an analogue to the M = 9 Kamchatka earthquake of November 4, 1952. The spatial distribution of the epicenters and the focal mechanisms of the aftershocks indicate that the repeated shocks during the Sumatran event were caused by the activation of a complex system of geological structures in various parts of the island arc and Andaman Sea instead of the slips on a single rupture (a subduction thrust about 1200-1300 km in length). [ABSTRACT FROM AUTHOR]

An interpretation of the type, size, and location of the source of the Aleutian earthquake on April 1, 1946, which was characterized by the highest intensity ( I = 4), is proposed. The earthquake source is a subvertical reverse fault striking along the island arc and dipping at an angle of 85° toward the deep-sea trench. The reverse fault is located in the lower part of the island slope, within the eastern termination of the Aleutian terrace. The western end of the reverse fault is located in the area of the Krenitsyn Islands (λ ∼ 165°W), where the pattern of isobaths changes, and an abrupt widening of the shelf part of the Fox Islands takes place. Large ( MS ∼ 7) shocks, preceding the 1946 earthquake, occurred here in 1940, 1942, and 1944. Structural inhomogeneities in the island slope in the area of the Sanak Islands (λ ∼ 162°W) determine the eastern edge of the source-reverse fault, whose length within the specified boundaries is about 200 km. The mean magnitude of the earthquake corresponding to such a source is ∼8.3. According to the regular relation between the rupture length and the mean movement, the vertical displacement of the ocean floor in the source region could attain 5–6 m. A significant vertical displacement of the ocean floor over its large length (∼200 km) was responsible for the high tsunamigenic ability of this earthquake. A favorable combination in the source area of the topographic and other conditions necessary for the tsunami formation could additionally contribute to an increase in the intensity of the tsunami. The earthquake of April 1, 1946, in the Fox Islands, as well as the tsunamigenic earthquakes of March 9, 1957, in the Andreanof Islands and February 4, 1965, in the Rat Islands, does not belong to the class of “slow” earthquakes. [ABSTRACT FROM AUTHOR]

The spatiotemporal evolution of the intense burst in seismogenesis within the Andaman-Sumatra island arc in 2000-2010 is analyzed. The onset of seismogenic activation was marked by two strong ( M ∼ 7.9, M ∼ 7.8) quakes that occurred in the lithosphere of the South Sumatra region on June 4, 2000 and by the strongest ( M = 7.3) earthquake of July 25, 2004 that took place in the lower part of the focal zone. These seismic events were the foreshocks of the main episode of seismogenic activation of the island arc-the catastrophic earthquake of December 26, 2004, with its source near the northern coast of Sumatra. The large shocks ( M ∼ 7.7-8.4) that occurred from March 28, 2005 to October 25, 2010 between the source of the Sumatran earthquake and epicentral zone of the foreshocks of June 4, 2000, are the aftershocks of the Sumatran event. The spatiotemporal evolution of seismogenic activation of the Andaman-Sumatra island arc at the beginning of the 21 century is compared to the seismogenic activation of the Kuril-Kamchatka arc in the middle of the 20 century. The positions, geological conditions, and focal parameters of the strongest Sumatran earthquakes of 2000-2010 are determined. The interpretation of the sources relies on the (1) complex analysis of all the manifestations of the earthquakes of 2000-2010 and (2) the established regularities of the occurrence of the earthquakes in the island arcs. The sources of the earthquakes of 2005-2010 are the steep longitudinal (trending along the arc) reverse faults of a backthrust type, which have a bedding depth of about a few dozen kilometers. The reverse-fault sources of the earthquakes of March 28, 2005, September 12, 2007 (11:10 UT), and October 10, 2010 are located in the zone of the Outer Range, and the earthquakes of September 12, 2007 (23:49 UT) fall in the Mentawai Trough. The strike-slip reverse fault, which cuts the island arc, is likely to be the focal mechanism of the earthquake of June 4, 2000. The sources of the events of March 28, 2005 and September 12, 2007 did not coincide with the sources of the historical devastating earthquakes of 1861 and 1833, respectively. The system of seismic sources in the form of a series of subparallel arc-parallel steep reverse faults off the western coast of Sumatra is similar to the system of seismic sources in the Kuril-Kamchatka island arc. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are frequently used for hydrogen applications due to their high ductility at low temperatures and lower hydrogen environment embrittlement compared to ferritic steels. We study the effect of electrochemical hydrogen saturation up to 40 h on tensile behavior and fracture mechanisms in high-nitrogen austenitic 17Cr-24Mn-1.3V-0.2C-1.3N steel. Hydrogen saturation weakly influences the characteristic of stress-strain curves, but decreases steel ductility, yield stress, and ultimate tensile stress. Hydrogenation provides a change in steel fracture peculiarities-a hydrogen-assisted thin brittle surface layer of ≈5 μm and ductile subsurface layer of 50-150 μm in width in hydrogen-saturated specimens. The subsurface layer shows ductile transgranular fracture with elongated dimples and flat facets. The central parts of fracture surfaces for hydrogenated specimens show ductile fracture mode similar to hydrogen-free state, but they include numerous secondary cracks both for central part and for transition zone between ductile central part and subsurface layer associated with highest hydrogen saturation. The possible reasons of decrease in hydrogen-associated ductility and change in fracture character are discussed. [ABSTRACT FROM AUTHOR]

The paper studies the effect of electrolytic hydrogen charging on the plastic flow, strength properties, ductility, and fracture mechanisms in austenitic stainless steels Cr17Ni13Mo3C0.01, Cr18Ni10TiC0.12, and Cr18Ni9C0.17 with different stacking fault energies. The investigated steels are subjected to warm ABC-pressing and thermomechanical processing, including cold rolling and annealing, to produce the ultrafine-grained structure of different morphologies, such as ultrafine-grained (submicrocrystalline), misoriented grain-subgrain and mixed (grain and subgrain) structures of submicron scale. The strength properties of the steels after warm pressing and rolling with annealing exceed 3.5–6.0 times the properties of the quenched steels with coarse-grained structure. Electrolytic hydrogen charging of the studied steels with submicron-sized structure reduces the yield strength irrespective of the grain/subgrain size, structure, steel composition, and its stacking fault energy. The formation of a highly defective grain-subgrain structure with high dislocation density suppresses the effect of hydrogen embrittlement in Cr17Ni13Mo3C0.01 and Cr18Ni10TiC0.12 steels, in which no or a small volume fraction of strain-induced α′ martensite forms in tension. The tempering of the highly defective structure and the formation of a large fraction of high-angle misorientations in the stable Cr17Ni13Mo3C0.01 steel enhances the effect of hydrogen embrittlement in the specimens as compared to the specimens with a grain-subgrain structure with a high density of dislocations and low-angle boundaries. The hydrogen embrittlement effects are most pronounced in ultrafine-grained (submicrocrystalline) Cr18Ni10TiC0.12 and Cr18Ni9C0.17 steels with predominantly grain structure, which undergo induced γ→α′ phase transformation. [ABSTRACT FROM AUTHOR]

An organizational structure consists of a network where employees are connected by working and social ties. Analyzing this network, one can discover valuable insights into information flow within the organization. We develop this idea and propose a simple network model that is consistent with management theory, and that captures main traits of large corporations. The carcass of the model is an organizational hierarchy. We extend it by allowing additional types of connections such as collaboration, consultation, and friendship. Having both formal and informal interpersonal ties, our model supports a multilevel approach to social networks. Using a centrality-based definition of power, we are able to identify important individuals in the network. Our model provides novel insights into a range of organizational properties: (1) organizations have limited hierarchy height. (2) Flattening, the process when a business changes from a tall to a flat hierarchy by delayering, is intimately related to changes in the power of employees. (3) Informal relations significantly impact power of individuals. (4) Leadership styles could be reflected and analyzed through understanding weights on the ties in an organizational network. We implement our model and tools in a stand-alone application $${\mathsf{CORPNET}}$$ , which provides functions for generating synthesized organizational networks, analyzing and visualizing interpersonal relations, and computing network measures. [ABSTRACT FROM AUTHOR]

[Figure not available: see fulltext.] An efficient approach based on pyrone ring opening in 3-arylisocoumarins in the presence of cyclic secondary amines was developed in order to prepare amides of deoxybenzoin-2'-carboxylic acids, diverse functionalized structures useful for the synthesis of polyfunctional compounds. [ABSTRACT FROM AUTHOR]

Additional information about risk genes or risk pathways for diseases can be extracted from genome-wide association studies through analyses of groups of markers. The most commonly employed approaches involve combining individual marker data by adding the test statistics, or summing the logarithms of their P-values, and then using permutation testing to derive empirical P-values that allow for the statistical dependence of single-marker tests arising from linkage disequilibrium (LD). In the present study, we use simulated data to show that these approaches fail to reflect the structure of the sampling error, and the effect of this is to give undue weight to correlated markers. We show that the results obtained are internally inconsistent in the presence of strong LD, and are externally inconsistent with the results derived from multi-locus analysis. We also show that the results obtained from regression and multivariate Hotelling T2 (H-T2) testing, but not those obtained from permutations, are consistent with the theoretically expected distributions, and that the H-T2 test has greater power to detect gene-wide associations in real datasets. Finally, we show that while the results from permutation testing can be made to approximate those from regression and multivariate Hotelling T2 testing through aggressive LD pruning of markers, this comes at the cost of loss of information. We conclude that when conducting multi-locus analyses of sets of single-nucleotide polymorphisms, regression or multivariate Hotelling T2 testing, which give equivalent results, are preferable to the other more commonly applied approaches. [ABSTRACT FROM AUTHOR]

Spectral-fluorescent properties of 6-pyrazolyl-4-methylubbelliferone have been investigated in comparison with 4-methylumbelliferone and its methyl ester. Abnormally large Stokes shifts and the fluorescence ability of these compounds have been interpreted using quantum-chemical analysis by the DFT and TDDFT methods with the B3LYP/6-31G(d,p) basis set of the change of charge and bond orders in the ground and first excited states. It has been established that the significant difference in the absorption and fluorescence spectra of the studied 7-hydroxycoumarins in proton-donor solvents is caused by proton abstraction and transfer in their neutral form upon photoexcitation with probable formation of the anion and the tautomer depending the pH of the medium. It has been shown that the formation probability for these species is increased by introducing the pyrazolyl cycle in the 6-position of 4-methylumbelliferone. [ABSTRACT FROM AUTHOR]

The spatiotemporal manifestations of seismicity in the Andaman-Sumatra island arc are studied using the instrumental data for 1900-2010. The data on the largest tsunamigenic earthquakes of the 18th-19th centuries were also taken into account. The epicenters of the earthquakes are established to cluster in some areas; their possible relation to the structural features of the island arc is considered. A distinctive feature of seismicity in the region of the Andaman Sea is the presence of compact swarms of numerous earthquakes occurring during short intervals of time. The distribution of the earthquakes by the depth of their hypocenters in different segments of the island arc is investigated. The focal mechanisms of the earthquakes are analyzed using the centroid-moment-tensor (CMT) determinations over the period of 1980-2004, and the characteristic features of their parameters in different segments of the Andaman-Sumatra island arc are formulated. The focal parameters of the earthquakes determined by CMT and the moment-tensor-solution (MTS) are compared; the possible uncertainty in the estimates of the focal mechanisms is assessed. The pattern of the spatiotemporal manifestations of the Andaman-Sumatra earthquakes and their focal mechanisms are compared to the data on the Kuril-Kamchatka and the Aleutian island arcs previously studied by the authors. The results of analyzing the long-term seismicity and focal mechanisms in the Andaman-Sumatra island arc provide a necessary basis for the further thorough investigation of the geological conditions and source parameters of the major Sumatra earthquakes of 2000-2010. [ABSTRACT FROM AUTHOR]

Genome-wide association (GWAS) analyses have identified susceptibility loci for many diseases, but most risk for any complex disorder remains unattributed. There is therefore scope for complementary approaches to these data sets. Gene-wide approaches potentially offer additional insights. They might identify association to genes through multiple signals. Also, by providing support for genes rather than single nucleotide polymorphisms (SNPs), they offer an additional opportunity to compare the results across data sets. We have undertaken gene-wide analysis of two GWAS data sets: schizophrenia and bipolar disorder. We performed two forms of analysis, one based on the smallest P-value per gene, the other on a truncated product of P method. For each data set and at a range of statistical thresholds, we observed significantly more SNPs within genes (Pmin for excess<0.001) showing evidence for association than expected whereas this was not true for extragenic SNPs (Pmin for excess>0.1). At a range of thresholds of significance, we also observed substantially more associated genes than expected (Pmin for excess in schizophrenia=1.8 × 10−8, in bipolar=2.4 × 10−6). Moreover, an excess of genes showed evidence for association across disorders. Among those genes surpassing thresholds highly enriched for true association, we observed evidence for association to genes reported in other GWAS data sets (CACNA1C) or to closely related family members of those genes including CSF2RB, CACNA1B and DGKI. Our analyses show that association signals are enriched in and around genes, large numbers of genes contribute to both disorders and gene-wide analyses offer useful complementary approaches to more standard methods.Molecular Psychiatry (2009) 14, 252–260; doi:10.1038/mp.2008.133; published online 9 December 2008 [ABSTRACT FROM AUTHOR]

Abstract  New functionalized derivatives of 8,8,10-trimethyl-4-phenyl-7,8-dihydro-2H,6H-pyrano[3,2-g]-chromene-2,6-dione – analogues of the natural compound graveolone – possessing hydrazine, hydroxylamine, and thiosemicarbazide residues were synthesized and their reactions with acetic anhydride were studied. The structure of the obtained compounds was confirmed by NMR spectroscopy. [ABSTRACT FROM AUTHOR]

An interpretation of the type, size, and interrelations of sources is proposed for the three large Aleutian earthquakes of March 9, 1957, May 7, 1986, and June 10, 1996, which occurred in structures of the Andreanof Islands. According to our interpretation, the earthquakes were caused by steep reverse faults confined to different structural units of the southern slope of the Andreanof Islands and oriented along the strike of these structures. An E-W reverse fault that generated the largest earthquake of 1957 is located within the Aleutian Terrace and genetically appears to be associated with the development of the submarine Hawley Ridge. The western and eastern boundaries of this source are structurally well expressed by the Adak Canyon in the west (∼177°W) and an abrupt change in isobaths in the east (∼173°W). The character of the boundaries is reflected in the focal mechanisms. The source of the earthquake of 1957 extends for about 300 km, which agrees well with modern estimates of its magnitude ( M w = 8.6). Because the earthquake of 1957 caused, due to its high strength, seismic activation of adjacent areas of the Aleutian island arc, its aftershock zone appreciably exceeded in size the earthquake source. Reverse faults that activated the seismic sources of the earthquakes of 1986 and 1996 were located within the southern slope of the Andreanof Islands, higher than the Aleutian Terrace, outside the seismic source of the 1957 earthquake. The boundaries of these sources are also well expressed in structures and focal mechanisms. According to our estimate, the length of the 1986 earthquake source does not exceed 130–140 km, which does not contradict its magnitude ( M w = 8). The length of the 1996 earthquake source is ∼100 km, which also agrees with the magnitude of the earthquake ( M w = 7.8). [ABSTRACT FROM AUTHOR]