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By condensation of 1-(4-alkoxyphenyl)ethanones with aromatic aldehydes in the presence of sodium hydroxide in an aqueous-ethanol solution, (2E)-3-aryl-1-(4-alkoxyphenyl)prop-2-ene-1-ones were obtained. Cyclization of these latter with phenylhydrazine in an acidic medium leads to the corresponding 5-aryl-3-(4-alkoxyphenyl)-1-phenyl-4,5-dihydro-1H-pyrazoles. The luminescent, antimonoamine oxidase, and antioxidant properties of the compounds obtained were studied. [ABSTRACT FROM AUTHOR]

Osteoarthritis is a degenerative disease that affects articular cartilage, leading to changes on the macro and micro levels of this multi-component tissue. Understanding the processes underlying this pathology plays an important role in planning the following management tactics. Timely detection of the knee joint degradation at the level of tissue changes can prevent its progressive damage due to the early beginning of appropriate treatment. This study aimed to provide an overview of the current level of knowledge about the composition of cartilage and menisci using a wide range of different diagnostic methods. A systematic review of the literature published from 1978 to 2023 was conducted. Original studies of the knee joint cartilage (articular and meniscus) research, reporting content composition and mechanical properties, were included. Studies of the non-knee joint cartilage, tissue research other than cartilage and meniscus, or reporting treatment outcomes were excluded (n = 111). Thirty-one papers were included in this review, which reported on the composition of animal and human cartilage (articular and meniscus). The most frequently investigated parameters were quantitative proteoglycan determination and hydration level of the cartilage. Cartilage and meniscus degeneration, i.e., reduced collagen and proteoglycan content, reduced mechanical properties, and increased hydration level, was shown in every article about osteoarthritis. Among all diagnostic methods, laboratory methods (biochemical and histological analysis) are the most frequently used, compared to the instrumental ones (spectroscopy, MRI, and CT). At the same time, spectroscopy takes the lead and becomes the most common approach for determining cartilage composition (collagen and proteoglycans content). [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the dynamics of oxidative stress (OS) development, as well as adaptive response of select enzymes induced by low-energy laser-driven ultrashort pulsed electron beam whole-body irradiation in a Wistar rat brain. The rats were exposed to irradiation at the LD50 dose, following which the levels of the OS, the activities of major antioxidant enzymes, namely superoxide dismutase (SOD) and catalase (CAT), the activity of purine nucleoside phosphorylase (PNP) serving as an indicator of body's immune status, the activity of the key enzyme of energy metabolism, namely creatine kinase (CK), as well as the amount of creatine were assessed on the 1st, 3rd, 7th, 14th, and 28th post-irradiation days. It has been demonstrated that: 1) the maximum intensity of OS occurs between the 1st and the 7th post-irradiation days, followed by a significant decrease detected on the 14th day and return to a control level on the 28th post-irradiation day; 2) the moderate drop in the activity levels, for SOD and CK, or fluctuations in the activity around the control level for CAT during the first post-irradiation days are replaced by the restoration of the initial activity levels for SOD and CK or a compensatory rise in the enzyme activity level for CAT by the 14th and 28th post-irradiation days—sufficient to neutralize the radiation-induced OS; 3) the identified dynamics of the changes of the parameters studied coincides with the terms of the start and end of the acute phase of brain injury induced by ionizing radiation. [ABSTRACT FROM AUTHOR]

An efficient procedure has been proposed for the reaction of molecular iodine with phenylacetylene in the presence of cadmium(II) acetate in DMSO at room temperature, and the reactant ratio has been optimized for the iodination process. Mercuration–demercuration of iodoethynylbenzene with molecular iodine and oxidative homocoupling in the presence of dilithium tetrachlorocuprate have been performed. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests a considerable role of pre-movement beta bursts for motor control and its impairment in Parkinson's disease. However, whether beta bursts occur during precise and prolonged movements and if they affect fine motor control remains unclear. To investigate the role of within-movement beta bursts for fine motor control, we here combine invasive electrophysiological recordings and clinical deep brain stimulation in the subthalamic nucleus in 19 patients with Parkinson's disease performing a context-varying task that comprised template-guided and free spiral drawing. We determined beta bursts in narrow frequency bands around patient-specific peaks and assessed burst amplitude, duration, and their immediate impact on drawing speed. We reveal that beta bursts occur during the execution of drawing movements with reduced duration and amplitude in comparison to rest. Exclusively when drawing freely, they parallel reductions in acceleration. Deep brain stimulation increases the acceleration around beta bursts in addition to a general increase in drawing velocity and improvements of clinical function. These results provide evidence for a diverse and task-specific role of subthalamic beta bursts for fine motor control in Parkinson's disease; suggesting that pathological beta bursts act in a context dependent manner, which can be targeted by clinical deep brain stimulation. How movement speed is neurally modulated remains poorly understood. Here, the authors recorded invasive brain signals in Parkinson's disease patients during drawing and deep brain stimulation, showing a context-dependent relationship between reductions of movement acceleration and dynamic activity of the basal ganglia. [ABSTRACT FROM AUTHOR]

The reaction of (1,2-dibromoethyl)(diphenyl)phosphine oxide with CH-acids (acetylacetone, acetoacetic ester, and malonic ester) in the presence of sodium hydroxide has afforded diphenylphosphoryl-substituted cyclopropanes in high yield. It has been shown that the reaction of (1,2-dibromoethyl)(diphenyl)phosphine oxide with primary arylamines leads to the formation of bis(phosphine oxides), in contrast to alkylamines which lead to phosphoryl-substituted aziridines. [ABSTRACT FROM AUTHOR]

The water and DMSO solutions of two new synthesized compounds, β-dimethylaminoethylamidine N-benzoyl-DL-valineiodomethylate (TVA) and 1-(β-diethylaminoethyl)-2-phenyl-4-benzylidene-5-imidazolone (TVS), were characterized by optical absorbance and fluorescence properties. Earlier, the antiacetylcholinesterase and antibutyrylcholinesterase activities of these compounds have been shown. To prove the eligibility of their use against Alzheimer's disease, the present study demonstrates the ability of the compounds to reduce the aggregation degree of commercial Aβ(1-42) amyloid peptide in vitro. From the concentration dependences, their IC50 values were estimated in the deceleration of Aβ(1-42) aggregation (1.56 ± 0.3 mM for TVA and 1.8 ± 0.28 mM for TVS). The effective destabilization of the preformed aggregates of the peptide was registered with the IC50 values of 0.54 ± 0.06 and 0.67 ± 0.2 mM, for TVA and TVS, respectively. Cell culture experiments have shown the effectiveness of the synthesized compounds in protection the rat hippocampal cells against cytotoxic action of Aβ(1-42) aggregates: during 7 days incubation, the number of neurospheres per microscopic field in the presence of the peptide aggregates fallen down to 34% of the intact cells, but 2 μg/mL TVA kept the cells on the level of the intact, and 5 μg/mL TVS—on the level of 77% of the intact. Subsequent developments based on these compounds will allow the researchers to create the preparations valid for pre-clinical studies with goal to introduce into medical practice as new remedies in prevention/treatment of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

In this article has been achieved that the utilization of quantum programmable logic elements opens new possibilities in cryptography, where the ability to process information irreversibly contributes to enhanced security measures. Furthermore, the development of such elements fosters the advancement of complex computational architectures, facilitating the creation of sophisticated and highly efficient systems. [ABSTRACT FROM AUTHOR]

The article proposes a hypothesis for the functioning of a diatom population under conditions of clearly defined water column stratification. It is assumed that cells in the upper illuminated water layer accumulate biomass based on photosynthesis. In the lower layer, which is rich in minerals, cells replenish their intracellular reserves. Movement from one layer to another allows cells to compensate for lack of resources. Sinking occurs as a result of sedimentation and lifting results from the release of carbon dioxide microbubbles during respiration. This hypothesis was used to construct an agent-based model of a diatom population. Calculations have shown that vertical movements maintain the existence of the population. Different regimes of surface illumination make it possible to obtain various distributions of cell numbers in the upper and lower water layers, which is consistent with the data of expeditionary observations. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to describe and assess the current stage of the artificial intelligence (AI) technology integration in preventive orthopaedics of the knee and hip joints.Materials and Methods: The study was conducted in strict compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Literature databases were searched for articles describing the development and validation of AI models aimed at diagnosing knee or hip joint pathologies or predicting their development or course in patients. The quality of the included articles was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and QUADAS-AI tools.Results: 56 articles were found that meet all the inclusion criteria. We identified two problems that block the full integration of AI into the routine of an orthopaedic physician. The first of them is related to the insufficient amount, variety and quality of data for training, and validation and testing of AI models. The second problem is the rarity of rational evaluation of models, which is why their real quality cannot always be evaluated.Conclusion: The vastness and relevance of the studied topic are beyond doubt. Qualitative and optimally validated models exist in all four scopes considered. Additional optimization and confirmation of the models' quality on various datasets are the last technical stumbling blocks for creating usable software and integrating them into the routine of an orthopaedic physician. [ABSTRACT FROM AUTHOR]

Monitoring of the photosynthetic activity of natural and artificial biocenoses is of crucial importance. Photosynthesis is the basis for the existence of life on Earth, and a decrease in primary photosynthetic production due to anthropogenic influences can have catastrophic consequences. Currently, great efforts are being made to create technologies that allow continuous monitoring of the state of the photosynthetic apparatus of terrestrial plants and microalgae. There are several sources of information suitable for assessing photosynthetic activity, including gas exchange and optical (reflectance and fluorescence) measurements. The advent of inexpensive optical sensors makes it possible to collect data locally (manually or using autonomous sea and land stations) and globally (using aircraft and satellite imaging). In this review, we consider machine learning methods proposed for determining the functional parameters of photosynthesis based on local and remote optical measurements (hyperspectral imaging, solar-induced chlorophyll fluorescence, local chlorophyll fluorescence imaging, and various techniques of fast and delayed chlorophyll fluorescence induction). These include classical and novel (such as Partial Least Squares) regression methods, unsupervised cluster analysis techniques, various classification methods (support vector machine, random forest, etc.) and artificial neural networks (multilayer perceptron, long short-term memory, etc.). Special aspects of time-series analysis are considered. Applicability of particular information sources and mathematical methods for assessment of water quality and prediction of algal blooms, for estimation of primary productivity of biocenoses, stress tolerance of agricultural plants, etc. is discussed. [ABSTRACT FROM AUTHOR]

The condensation of 1-alkylisatines with malononitrile and 8-hydroxyquinoline or 5,5-dimethyl-cyclohexane-1,3-dione in the presence of an aqueous solution of trimethylamine proceeds regioselectively as a one-pot three-component domino process to form spiro[chromene-4,3'-indoline] and spiro(indoline-3,4'-pyrano[3,2-h]quinoline). [ABSTRACT FROM AUTHOR]

Tests on propane pyrolysis in a two-sectioned flow reactor have shown that the introduction of ethylene into the feed mixture leads to an increase in the propylene yield. Under certain conditions, the ethylene content in the mixture at the inlet and outlet of the reactor remains constant. At high temperatures, the process can be accompanied by the formation of tarry products. The absence of oxygen-containing byproducts makes the cocracking of propane and ethylene more attractive than the oxidative pyrolysis of propane. [ABSTRACT FROM AUTHOR]

The magnetic and some physicochemical properties of glasses based on barium-borosilicate eutectic doped with iron and lithium oxides were studied. The magnetic permeability increases with increasing content of Fe2O3. The character of magnetic permeability remains unchanged when Fe2O3 and Li2O are introduced simultaneously. The formation of structural motifs of barium hexaferrite in glass is responsible for magnetic properties. According to EPR data, some iron ions are present in tetrahedral coordination, incorporating into the structural mesh of the glass, and the others in octahedral coordination, acting as a modifier. [ABSTRACT FROM AUTHOR]

The reactions of nucleophilic addition of СН-acids to terminal alkynes under electrophilic catalysis with mercury(II) acetate were studied. As a result of mercury-demercuration reactions, the corresponding aromatic and linear derivatives were obtained. A method was proposed for the regeneration of the resulting amorphous mercury by reduction into mercury(II) acetate. [ABSTRACT FROM AUTHOR]

A fundamentally new microfluorimeter is designed to assess the functional state of primary photosynthesis in individual phytoplanktonic cells. The device is tested during a sea expedition. It allows estimation of the amount of photosynthetic pigments, the primary photosynthetic efficiency, the light slope of the linear electron-transfer rate (light response curve) as well as the degree of nonphotochemical quenching of excited pigment molecules in every cell found in a studied phytoplankton community. This data enables plotting of the distribution diagrams of algal cells for each of the listed characteristics within the population of every algal species. The microfluorimeter has a convenient graphic interface where a user can save the measurement results to spreadsheets. The detection limit of the device is equal to 1 pg of chlorophyll inside the photometric volume. This sensitivity is high enough for the reliable quantification of chlorophyll-fluorescence parameters of individual algal cells. The microfluorimeter is equipped with a system that maintains the object temperature constant over a wide temperature range limited from below by the dew point and water condensation on the cover-glass surface. [ABSTRACT FROM AUTHOR]

Essential tremor is a common neurological disorder, characterised by involuntary shaking of a limb. Patients are usually treated using medications which have limited effects on tremor and may cause side-effects. Surgical therapies are effective in reducing essential tremor, however, the invasive nature of these therapies together with the high cost, greatly limit the number of patients benefiting from them. Non-invasive therapies have gained increasing traction to meet this clinical need. Here, we test a non-invasive and closed-loop electrical stimulation paradigm which tracks peripheral tremor and targets thalamic afferents to modulate the central oscillators underlying tremor. To this end, 9 patients had electrical stimulation delivered to the median nerve locked to different phases of tremor. Peripheral stimulation induced a subtle but significant modulation in five out of nine patients—this modulation consisted mainly of amplification rather than suppression of tremor amplitude. Modulatory effects of stimulation were more pronounced when patient's tremor was spontaneously weaker at stimulation onset, when significant modulation became more frequent amongst subjects. This data suggests that for selected individuals, a more sophisticated control policy entailing an online estimate of both tremor phase and amplitude, should be considered in further explorations of the treatment potential of tremor phase-locked peripheral stimulation. [ABSTRACT FROM AUTHOR]

'Ecological photobiology' session of the Russian Photobiology Society 9th Congress was devoted to a wide range of problems related to the assessment of the environmental state by photobiological methods and included oral presentations and a poster session. A short survey of these presentations is given. [ABSTRACT FROM AUTHOR]

The phytoplankton activity was analyzed in June 2015 in Onega Bay of the White Sea. The chlorophyll a concentration, as well as cell abundance and cell biomass, were assessed in natural phytoplankton samples and individually for the picoplankton fraction. These data were compared with the results of additional optical measurements for the same water samples. A strong correlation (R2 = 0.82) was found between chlorophyll absorbance (~680 nm, absorbance spectra) and in vivo chlorophyll fluorescence intensity. Мicroalgae had a high level of photosynthetic efficiency (Fv/Fm > 0.4). The picoplankton fraction was characterized by less efficient photosynthesis, probably due to the presence of cyanobacteria. The picoplankton fraction contributed a few percent to the total biomass, whereas its contribution to the total chlorophyll fluorescence intensity reached up to 40%. [ABSTRACT FROM AUTHOR]

The search for microorganisms in cosmic bodies of the Solar System is of great importance for understanding the problem of the origin of life. At present, it is difficult to create specialized laboratories searching for living microorganisms on the surface of planets or cosmic bodies that either formed in the Solar System or were captured by the Solar gravity from interstellar space. Existing experiments on search for life on landers and planet research vehicles allow this research to be conducted on the surface of planets and their satellites, but on a limited area near the landing site. This paper considers a method of remote sensing of outer space by light flashes of cosmic objects to detect bioactivity on almost all of their surfaces. The presence of bioactivity is the detected by specific luminescence of microorganisms when they are illuminated by probing radiation that causes their fluorescence. [ABSTRACT FROM AUTHOR]

Bioindication, a method for the assessment of the quality of the natural environment with allowance for the state of the biota, is widely used to assess the impact of various factors on an ecosystem. Two problems remain relevant: on the one hand, the adequate selection of biological indicators of the ecosystem state with the greatest bioindicative potential, and, on the other, the establishment of the numerical boundaries of the norm for the indicators. A laboratory algocenosis has been created to study the bioindicational potential of hydrobiological and biophysical indicators. It consists of representatives of various classes of microalgae and cyanobacteria: Anabaena variabilis, Pleurochloris magna, Ankistrodesmus falcatus, and Stichococcus bacillaris. Salts of copper and zinc and diuron were used as effective toxicants. The method of local ecological norms was used for the analysis of the experimental data. The method is based on a computer analysis of the interrelated distribution of biological and physicochemical characteristics, i.e., on the search for boundaries of the factor and indicator norms for which suitable values of the indicator correspond to acceptable values of the factor and unacceptable values of the factor correspond to unsuitable indicator values. The paper analyzes data on 27 bioindicators: various fluorescence indicators, spectral characteristics; number and average volumes of cells of each type; parameters of the rank distribution of the number of species in the sample; evenness indices; nonparametric indices of species diversity; and the phytoplankton saprobity index. The boundaries of each indicator norm have been calculated; the most significant factors, as well as the boundaries of those factors' norm, have been revealed and determined. The bioindicators were compared by the average strength of connection with factors, the number of found significant factors, and their geometric mean value. [ABSTRACT FROM AUTHOR]

New substituted spiro[chromene-4,3′-indoles] and spiro[indole-3,4′-quinolines] have been synthesized in 35-65% yields by one-pot regioselective three-component condensation of N-substituted isatins with two active methylene compounds. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is central to storing and exchange of energy and information in cells including those of microalgae. The overwhelming majority of microalgae are naturally acclimated to low-P environments; hence, they are capable of taking up and storing P in large amounts whenever it becomes available. The ability to take up more P than necessary for immediate growth is termed "luxury uptake." Understanding this phenomenon constitutes a crucial insight into nutrient-driven processes in natural algal communities such as harmful algal blooms, as well as into the operation of algae-based technologies for sustainable usage of P such as recycling of the nutrient from wastewater to biofertilizers. The bulk of P acquired during luxury uptake is stored in the form of inorganic polyphosphate, the compound with nearly ubiquitous presence and multifaceted function in the cell. Although seminal works on luxury P uptake and polyphosphate metabolism were carried out fifty years ago, application of modern "omics" approaches and advanced imaging microscopy techniques enabled obtaining a deeper mechanistic insight into these processes. Nevertheless, our knowledge about luxury P uptake remains much more limited in comparison with that about P shortage and mechanism tolerance to this stress in microalgae. In this review the knowledge of luxury P uptake originating from classical phycological and biochemical methods is confronted with the recently obtained understanding of molecular mechanisms of P transport to the cell, polyphosphate biosynthesis, regulation, and genetic control of these processes. Biotechnological implications of the knowledge about luxury P uptake accumulated to date are discussed in the context of algae-based approaches to sustained usage of nutrients and industrial cultivation of microalgae. [ABSTRACT FROM AUTHOR]

Abstract—The paper presents the results of monitoring of the photosynthetic activity of the green microalga Chlorella. A thermophilic strain of Chlorella with a high rate of cell division was cultivated in a photobioreactor. Three medium variants with different mineral composition were used. Chlorophyll fluorescence induction curves and microalgal suspension absorption spectra were recorded every hour during 40-hour culture growth for each medium. The method of spectral multiexponential approximation we have developed was used to analyze 120 induction curves obtained after monitoring. This method revealed the dynamics of gradual changes in the number of phases of induction curves, their amplitudes and characteristic times during culture growth. The relationship between the parameters of induction curves and electron transfer processes in the reaction center of photosystem II allowed for interpretation of the changes in the shape of the induction curves in terms of the processes in the reaction center of photosystem II. The spectral multiexponential approximation method was shown to be highly sensitive to physiological state of microalgae and suitable for analyzing a huge amount of experimental data. The physiological processes accompanying the depletion of nitrogen in the environment are discussed. [ABSTRACT FROM AUTHOR]

A description, the scientific and technical tasks, and the development projects of the system of objective remote monitoring of facilities and resources in Russia are presented. The main objective of such a system is to obtain objective operational information for assessing the current state of regions, their resource potential, planning directions for the development of the country, and objective monitoring of the implementation of infrastructure projects. The proposed system can be an integral part of complex scientific and technological projects and programs aimed at solving the problems of connectedness of the territory of Russia. [ABSTRACT FROM AUTHOR]

The main instrument for implementing the Strategy for the Scientific and Technological Development of the Russian Federation should be integrated scientific and technical programs and projects of the full innovation cycle, the selection and development of which are assigned to the councils on the priorities of scientific and technological development. The authors present an approach to designing such programs and projects worked out by the Council on the priority of scientific and technological development "Territorial Connectivity of the Russian Federation." The concept of "territorial connectivity" is defined, and its main types and subtypes are identified, which are characterized by the presence of specific social, economic, control, and administrative functions. The proposed sequence of steps is a targeted movement from defining the main directions of the program implementation to identifying relevant complex socio-economic problems within each area, and then to developing research plans, scientific and technical projects, and systemic measures of the state policy that ensure their solution. The "gate approach" applied to the program design makes it possible at each stage of its development and implementation to make the necessary adjustments and to organize effective communication with potential customers and participants. [ABSTRACT FROM AUTHOR]

The feasibility of the production of ethylene and heavier olefins by introducing methane into the products of a rich methane flame is experimentally demonstrated. Such a process is promising for the direct production of ethylene, propylene, and heavier olefins directly from methane, the main component of natural gas. [ABSTRACT FROM AUTHOR]

It has been shown that in the case of noncatalytic oxidative pyrolysis of propane, the admixture of ethylene in the reactants significantly increases the concentration of propylene in the products. This process can be arranged in such a manner that the ethylene will not be noticeably consumed, i.e., will actually act as a propylene formation catalyst. This arrangement opens up a possibility to design a selective process for producing propylene directly from propane. [ABSTRACT FROM AUTHOR]

Studies of the impact of inorganic phosphorus (Pi), an important nutrient, on the growth and physiological parameters of single-celled algae are important for investigations of the dynamics of phytoplankton abundance and productivity in natural ecosystems as well as in industrial systems for the cultivation of microalgae. Difficulties in carrying out such studies are associated with the complex kinetics of Pi uptake by cells and the ability of microalgae to store phosphorus in their cells. This situation necessitates efficient methods for express monitoring of microalgal cultures, such as the methods based on the registration of optical properties of cells, in particular absorption and scattering of light and fluorescence of chlorophyll contained in the cells. Here, the results of monitoring the cultures of the chlorophyte Chlorella vulgaris IPPAS C-1 starving for phosphorus are described. It was found that both optical (light absorption in the bands of the key pigments—chlorophylls and carotenoids) and luminescent (variable fluorescence of chlorophyll) parameters closely reflect the culture condition. Registration of optical properties required correction for the contribution of light scattering to the overall extinction of light by microalgal cell suspensions. At the same time, the light scattering signal is an accurate measure of the total number of suspended particles in the suspension. However, it is difficult to monitor cultures containing a significant amount of light-scattering particles lacking photosynthetic pigments (such as heterotrophic bacteria). For such cultures, the use of variable fluorescence- based parameter Fv/Fm reflecting the maximum photochemical efficiency of the photosystem II is advisable. [ABSTRACT FROM AUTHOR]

A mechanism of nucleation and formation of Ti-Cr coatings on synthetic diamond powders of grade HSD 90 has been revealed and investigated. The metal deposition has been found to occur selectively and heal surface defects (microcracks, steps, etc.). Ti is the matrix metal that forms the coating as a whole, while Cr is the alloying element. Thermal stability of metal-coated diamond powders has been studied by derivatography. It has been found out that in comparison to non-coated powders the coated ones have the oxidation resistance increased by 40°C and feature an interdiffusion at the coating-bond interface. [ABSTRACT FROM AUTHOR]

Onega Bay waters are characterized by a high content of chromophoric dissolved organic matter (CDOM). The absorbance spectra and fluorescence intensity (excitation wavelength 455 nm, emission wavelength >680 nm) were used to assess the distribution of CDOM content in water filtered through a GF/F filter. The CDOM content at different points in Onega Bay showed more than a fourfold difference, as inferred from the measured values. The CDOM content in surface waters was, as a rule, higher than in the deeper horizons. A higher CDOM content was measured near the Onega River, near the middle part of the Onega shore, and near the Pomor shore opposite the town of Belomorsk. River runoff is the major source of CDOM in Onega Bay water. The CDOM chemical composition in Onega Bay waters was heterogeneous. The ratio of the fluorescence intensity to the absorbance value was higher near the mouths of rivers and in intensive mixing zones than in water characterized by high salinity. A highly significant linear correlation (R2 = 0.7825) between water salinity and CDOM fluorescence intensity was demonstrated. The contribution of fluorescent compounds to river runoff CDOM is substantially higher than the contribution to the composition marine CDOM. [ABSTRACT FROM AUTHOR]

The influence of the ratio of the reactants on the characteristics of the cooxidation of ethylene and methane in a two-section flow reactor is examined. It is shown that the radical oxidation of ethylene implicates methane into the oxidation process. The interaction of the thereby formed methyl radicals with ethylene leads to a significant increase in the yield of propylene, an effect that enables to consider the co-oxidation of ethylene and methane as a promising method for producing propylene. A methane-rich flame stabilized on the surface of a flat permeable matrix is proposed as a more efficient source of methyl radicals for converting ethylene into propylene. [ABSTRACT FROM AUTHOR]

The influence of the initial concentration of oxygen and temperature on the oxidative conversion of propane in a two-sectional flow reactor at constant pressure and contact time was studied. It was shown that an increase in the initial concentration of oxygen not only increases the conversion of propane, but also affects the ratio of the reaction products. The yield of ethylene and propylene was found to depend on the initial propane to oxygen ratio and reaction temperature. [ABSTRACT FROM AUTHOR]

The combined effect of 3 mg/L potassium dichromate, 1.5 mg/L cadmium sulfate, and 100 g/L shungite on the growth of chlorococcales green microalgae culture Scenedesmus quadricauda (Turp.) Bréb. is studied. The toxic effect of potassium dichromate and cadmium sulfate on S. quadricauda is estimated by calculating the share of living and dead cells and physiological parameters. The toxic effect of heavy metals does not manifest itself under the combined action of potassium dichromate or cadmium sulfate and shungite on S. quadricauda. The best growth of the algae culture occurred only when only shungite was added to the culture medium. Shungite can be used to neutralize the toxic effect of heavy metals. [ABSTRACT FROM AUTHOR]

Phytoplankton communities can serve as bioindicators of the water system state. It is necessary to select the appropriate species of microalgae to develop a model of a natural ecosystem that will allow performing multifactor experiments on the influence of physicochemical factors on the biophysical and hydrobiological characteristics of phytoplankton. This study has allowed selecting six species from those available in a museum to establish a model algal community. We have found that similar conditions are required for their optimal growth (light, temperature, and medium nutrients' supply). A medium with low nitrogen content is proposed to be used as a basal medium. Under these conditions, the cells function in a proper way and the cultures show satisfactory growth, while the duration of reaching the stationary stage of growth (10-15 days) allows having more experiments for a limited time. The cells of the selected species have morphological differences that are sufficient for the automated identification within the polyculture. We have obtained the geometric characteristics of cells for the computer counting of each species in the community on the microphotographs. [ABSTRACT FROM AUTHOR]

The use of CALS technology in the development and preproduction of the SSJ100 airplane is outlined. [ABSTRACT FROM AUTHOR]

The optimal geometric and physical parameters of a stepped cylindrical shell are determined. These parameters are optimal in the sense that they ensure the maximum carrying capacity of the shell for its given overall size and weight. The shell is made of a composite material. The refined theory of anisotropic shells is used with consideration of transverse shear effects on the stress-strain state. [ABSTRACT FROM AUTHOR]

Eigenfunctions of the Schrödinger equation with the Coulomb potential in the imaginary Lobachevsky space are studied in two coordinate systems admitting solutions in terms of hypergeometric functions. Normalization and coefficients of mutual expansions for some sets of solutions are found. [ABSTRACT FROM AUTHOR]

The classical Kepler-Coulomb problem on the single-sheeted hyperboloid H is solved in the framework of the Hamilton-Jacobi equation. We have proven that all the bounded orbits are closed and periodic. The paths are ellipses or circles for finite motion. [ABSTRACT FROM AUTHOR]

Methods have been developed for the synthesis of new heterocyclic systems, spiro[chromene-4,3′- indoles] and spiro[indole-3,4′-quinolines] by the base-catalyzed domino reaction of isatins with 5,5-dimethylcyclohexane- 1,3-dione (or 5,5-dimethyl-3-anilinocyclohex-2-en-1-one) and ethyl cyanoacetate. [ABSTRACT FROM AUTHOR]

It has been shown that the high-temperature hydrogen treatment of aluminum oxide nanowires coated with a monolayer of titanium oxide causes them to curl into nanotubes as a result of self-organization. The physicochemical properties of the nanotubes of a composite aluminum oxide aerogel coated with titanium oxide have been studied using X-ray phase analysis (XRD) and transmission electron microscopy (TEM). As a result of TiO/AlO nanofibrous aerogel treatment with hydrogen, a conversion of amorphous aluminum oxide fibers into tubes of nanocrystalline η-AlO occurs, but in this case the titanium dioxide monolayer does not form a separate phase. A study of the porous structure by the low-temperature adsorption of nitrogen vapors has shown that the aerogels of TiO/AlO nanotubes have a developed mesoporous structure with a small amount of micropores and a specific surface of more than 300 m/g. An increase in the temperature of hydrogen treatment first leads to the growth of an increase in the specific surface to 348 m/g at 923 K, and then to a gradual decrease to 145 m/g at 1123 K. In this case, the diameter of mesopores corresponding to a maximum on a curve of the pore size distribution decreases from 35 nm for a freshly prepared sample to 25 nm at 923 K and to 20 nm at 1123 K. The most homogeneous pores of a 25 nm diameter have the samples activated at 923 K. As a result of the high-temperature hydrogen treatment of the samples, the number of primary adsorption centers of water vapor adsorption decreases about two times. The resulting samples of TiO/AlO aerogels are close in structure to the initial aluminum oxide, whose wires just form nanotubes having a surface coated with titanium dioxide. As a result of the interaction between molecules of titanium dioxide adsorbed on the surface of aluminum oxide tubes, a substantial densification of the composite structure occurs. [ABSTRACT FROM AUTHOR]

The experimental studies of granular structures based on ZnO films that are randomly arranged small areas, granules or crystallites, which have different conductivity and are in direct contact, were carried out. The influence of donor complex, consisting of an oxygen vacancy and interstitial zinc atom, the donor impurity Ga, and acceptor impurity Li on the structural conductivity of the films is considered. The specifics of the conductivity in lightly doped wide band gap semiconductors with hydrogen-like impurities are investigated. The influence of grain size and crystallite structure on the conductivity kinetics is discussed. A new method for current density determination as a function of the coordinates for thin conductive films is developed. The experimental data are interpreted on the basis of the percolation theory. [ABSTRACT FROM AUTHOR]

Buta-1,3-diene-1,4-diylbis(triphenylphosphonium) iodide reacted with alkanethiols at room temperature in the presence of triethylamine to give [4-(alkylsulfanyl)buta-1,3-diene-1-yl]triphenylphosphonium iodides and triphenylphosphine in high yields. Two presumable reaction mechanisms involving ethynylvinyl intermediate (formed via the Hofmann decomposition of the starting diiodide and the initially formed 1,4-adduct with a thiol) were discussed. [ABSTRACT FROM AUTHOR]

In the present work, the problem of the motion of the classical particle in the Kepler-Coulomb field in three-dimensional hyperbolic space H: z + z − z − z = R is solved in the framework of Hamilton-Jacobi equation. The requirements for the existence of bounded motion of particle are formulated. The equation of the trajectory of particle is obtained, and it is shown that all the finite trajectories are closed. It is also demonstrated that under the certain values (zero or negative) of the separation constant A the fall of the particle onto the center takes place. [ABSTRACT FROM AUTHOR]

In this note the Kepler-Coulomb problem in hyperbolic space H: z + z − z − z = R is discussed. [ABSTRACT FROM AUTHOR]

Mathematical programs with vanishing constraints constitute a new class of difficult optimization problems with important applications in optimal topology design of mechanical structures. Vanishing constraints usually violate standard constraint qualifications, which gives rise to serious difficulties in theoretical and numerical treatment of these problems. In this work, we suggest several globalization strategies for the active-set Newton-type methods developed earlier by the authors for this problem class, preserving superlinear convergence rate of these methods under weak assumptions. Preliminary numerical results demonstrate that our approach is rather promising and competitive with respect to the existing alternatives. [ABSTRACT FROM AUTHOR]

Age of patients and oxidative stress in brain cells may contribute to pathogenesis of Alzheimer's disease (AD). Erythrocytes (red blood cells, RBC) are considered as passive 'reporter cells' for the oxidative status of the whole body and remain poorly investigated in AD. The aim of this study was to assess whether the antioxidant status of RBC changes in aging and AD. Blood was taken from AD and non-Alzheimer's dementia patients, aged-matched and younger controls. The antioxidant status of RBC was evaluated in each person participated in the study by measuring levels of HO, organic hydroperoxides, glutathione (GSH) and glutathione disulfide (GSSG), activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and glucose-6-phosphate dehydrogenase. In both aging and dementia, oxidative stress in RBC was shown to increase as evidenced by elevated concentrations of HO, organic hydroperoxides, decreased GSH/GSSG ratio, and decreased glutathione S-transferase activity. Decreased glutathione peroxidase activity in RBC may be considered as a new peripheral marker for Alzheimer's disease while changes of other parameters of oxidative stress reflect age-related events. [ABSTRACT FROM AUTHOR]

Low-frequency oscillations in the basal ganglia are prominent in patients with Parkinson's disease off medication. Correlative and more recent interventional studies potentially implicate these rhythms in the pathophysiology of Parkinson's disease. However, effect sizes have generally been small and limited to bradykinesia. In this study, we investigate whether these effects extend to rigidity and are maintained in the on-medication state. We studied 24 sides in 12 patients on levodopa during bilateral stimulation of the STN at 5, 10, 20, 50, 130 Hz and in the off-stimulation state. Passive rigidity at the wrist was assessed clinically and with a torque-based mechanical device. Low-frequency stimulation at ≤20 Hz increased rigidity by 24 % overall ( p = 0.035), whereas high-frequency stimulation (130 Hz) reduced rigidity by 18 % ( p = 0.033). The effects of low-frequency stimulation (5, 10 and 20 Hz) were well correlated with each other for both flexion and extension ( r = 0.725 ± SEM 0.016 and 0.568 ± 0.009, respectively). Clinical assessments were unable to show an effect of low-frequency stimulation but did show a significant effect at 130 Hz ( p = 0.002). This study provides evidence consistent with a mechanistic link between oscillatory activity at low frequency and Parkinsonian rigidity and, in addition, validates a new method for rigidity quantification at the wrist. [ABSTRACT FROM AUTHOR]