It is impossible to reliably evaluate the ecotoxicity of small subtoxic doses of dioxins without duly taking into account how the factors of real exposure conditions affect their properties. The best approach in this regard may be biomonitoring of the initial manifestations of the toxic effects. In the present work, the authors studied bank voles ( Clethrionomys glareolus ) from the natural population living close to a dumpsite, and more specifically the summer-born adults and overwintered functional groups of animals that differed by the dioxin burden. Voles from the vivarium-kept line served as a control. The initial toxic effects were characterized by the expression levels of the following genetic markers: ahr, cyp1a2, keap1 , dnmt1 , dnmt3a , dnmt3b, LINE-1 and B1-SINE. The expression levels of the ahr, keap1, dnmt3a , and dnmt3b genes were statistically higher in the summer-born adult group than in the control voles. The expression of the cyp1a2 and keap1 genes was increased in the overwintered group compared to the control, while no differences were detected for dnmt1 , LINE-1 , and SINE B1 . The increase in the expression of the marker genes observed in the dioxin-exposed voles is in good correspondence with the mechanisms of formation and development of toxicological effects under the conditions of low-dose toxin action on several generations in the population. Our findings will contribute to the development of an evaluation technique that could be used in biomonitoring of the initial ecotoxicity effects in the dioxin-contaminated environment.

Один из подходов мониторинга загрязнения среды диоксинами – натурно-экспериментальные исследования. Апробирован метод оценки начальных токсических эффектов действия малых субтоксичных доз диоксинов, заключающийся в анализе уровня транскрипции (Т) генов-маркеров с помощью специально введенного статистического показателя Тмакс (максимального значения для каждого гена в контроле). Превышение Тмакс у экспонированных полёвок и высокая частота таких особей рассмотрены как следствие токсического действия.

To assess the ecotoxicity of low doses of dioxins is almost impossible without considering the in uence of real exposure conditions on these substances’ properties. The best approach to take these into account is the biomonitoring of the initial toxic e ects’ manifestation. We studied bank voles from population naturally exposed to dioxins, the summer-born adults and overwintered functional groups of animals di ered by dioxin body burden. Dioxin-free samples of a vivarium bank voles’ line served as a control. Initial e ects of ecotoxicity were characterized by transcriptional levels of genetic markers: ahr, cyp1a2, keap1, dnmt1, dnmt3a, dnmt3b, LINE-1 and B1-SINE. Summer-born functional group had signi cantly higher expression levels of ahr, keap1, dnmt3a and dnmt3b genes versus their control group. Overwintered functional group had elevated expression levels of cyp1a2 and keap1, but no changes were found versus controls for dnmt1, LINE-1 and SINE B1. The increased expression of marker genes in dioxin-exposed voles was quite well associated with toxic process’ mechanisms - their formation and progression under exposure of several generations to low sub-toxic doses. The data obtained will contribute to the development of a biomonitoring method for assessing the initial e ects of dioxin ecotoxicity.

AIM: To study the state of the genome by indicators of retrotransposon activity the gene encoding DNA methyltransferase 1 (DNMT1); DNA damage in animals from the natural population of the bank vole (Clethrionomys glareolus) living in the vicinity of a preserved landfill contaminated with low concentrations of dioxins (landfill of production and consumption waste "Salariyevo", Moscow). MATERIAL AND METHODS: The activity of ERV-L, B1, and L1 retrotransposons and the transcription level of the DNMT1 gene were evaluated by real-time PCR. The stability of DNA in liver and bone marrow cells was characterized by the comet assay method. Afterward, the obtained characteristics of the state (stability, reactivity, and damage) of the genome in response to environmental stress factors were compared in groups of animals from the study and conditionally control samples. RESULTS: The effects of a decrease in the activity of retrotransposons of classes B1 and L1, and an increase in DNMT1 gene expression level were revealed in voles from the natural population living under the long-term chronic exposure to low doses of dioxins decrease in the activity of retrotransposons of classes B1 and L1, and an increase in the expression level of the DNMT1 gene were revealed. An increased level of DNA damage (on average up to 56% of the DNA in the tail of the comet) was detected in hepatocytes, with the addition of winter environmental factors to the chronic effect of small subtoxic doses of dioxins. CONCLUSION: Suppression of retrotransposon activity and increased expression of its epigenetic regulator (DNMT1) are regarded as adaptive responses to long-term chronic exposure to low doses of dioxins polluting the environment. The alteration in the reactivity and destabilization of the genome indicates the launch of the initial mechanisms of the toxic process formation. The created and tested methodological base for its study opens up prospects for establishing a threshold level, and as a result, substantiating indicators for screening assessment of local (territorial) risk to public health by biomonitoring.

Представлен результат обоснования и апробации методической базы для осуществления мероприятий, направленных на минимизацию вредного воздействия на окружающую среду и здоровье населения, вызванного выбросами диоксинов, производимыми примитивными свалками отходов производства и потребления. Ее основой стал биомониторинг опосредованного средой воздействия диоксинов на мелких млекопитающих из природных популяций, а также первоначальный прогноз ожидаемого для человека уровня общей токсичности относительно накопленных в тканях животных конгенеров. Сравнение результатов исследований содержания диоксинов в окружающей среде и тканях ее обитателей на территориях экоцида во Вьетнаме и в окрестностях свалки «Саларьево» показало, что обитатели выбранных для обследований территорий во Вьетнаме и в России могли испытывать длительное опосредованное средой хроническое воздействие малых доз диоксинов (включая тетрахлордибензодиоксины, ТХДД). Средние и медианные значения показателей содержания ТХДД и общего количества диоксинов в тканях обследованных животных из окрестностей свалки оказались даже выше, чем в тканях живущих в настоящее время вьетнамских крестьян. Предлагается выделить широко распространенные виды мелких млекопитающих, обитающих на исследуемых территориях, как доступную практике биологическую модель для изучения общих закономерностей накопления диоксинов в условиях хронической экспозиции организмов малыми дозами экотоксикантов. The article presents the results of substantiation and testing a methodological base for implementation of measures aimed at minimizing the harmful effects on the environment and public health caused by dioxin emissions produced by primitive landfills of production and consumption waste. This methodology is based on biomonitoring of environment-mediated effects of dioxins on small mammals from natural populations, coupled with primary forecast of levels of general toxicity expected for humans caused by congeners accumulated in the animal tissues. Comparison of the results of measurements of dioxins levels in the environment and tissues of its inhabitants for two different testing sites - the ecocide areas in Vietnam and in the vicinity of the Salaryevo landfill (Novomoskovsky Administrative District, Russia) showed that the inhabitants of the areas selected for testing in Vietnam and Russia could experience long-term environment-mediated chronic exposure to low doses of dioxins (including tetrachlorodibenzodioxins, TCDD). The average and median values of the indicators of the TCDD content and the total amount of dioxins in the tissues of the examined animals from the vicinity of the landfill are found to be even higher than that in the tissues of the currently living Vietnamese peasants. It is proposed to turn to account the widespread species of small mammals inhabiting the studied territories as a practically available biological model for studying the general patterns of dioxin accumulation under conditions of chronic exposure of living organisms to low doses of the ecotoxicants.

The existing methods for obtaining amorphous wires of large diameters from a melt are considered. The advantages of the Ulitovsky–Taylor method for obtaining amorphous wires in a wide range of diameters with stable geometric characteristics are underlined. The factors that affect the process of obtaining “thick” amorphous wires by a continuous version of the Ulitovsky–Taylor method are analyzed. It is demonstrated why it is necessary to use alloys with a high glass-forming ability and with melting temperatures of 950–1150°C. The practicability of introducing technological additives (Nb, Mo, Cr, etc.) is justified. It is noted that, to ensure a continuous process of producing a “thick” wire, it is necessary to use a high-purity precursor with stable geometric parameters. A variant of a quenching device is proposed for cooling a melt jet with a counterflow of water. The technique for removing the glass cover is based on elastic bending of the metal core and brittle cracking of glass. The technology for producing “thick” wires was tested. Long wires with diameter of 50–200 μm with a high set of properties were manufactured.

Introduction The environmentally acceptable management of solid domestic and industrial waste is one of the most urgent problems in Russia. For example, the total number of authorized and natural landfills in the Moscow region reaches several thousand. In addition to the visible negative impact on the environment, such landfills, serve as a source of highly toxic chemicals. The 2,3,7,8-substituted congeners of the PCDD/Fs are the most toxic. These persistent toxic compounds are ubiquitous and highly bioaccumulative in nature. Their biological activity is determined by an ability to influence cellular energy capabilities, genome activity (with shifting in genes expression and signals transduction), and carcinogenicity. The world authorities overview these chemicals and the dioxinand POP-contaminated sites as challenges for human future generations well-being and health [1]. Accumulation of municipal solid wastes (MSW) in the open landfills near cities creates the possibility of the long-term exposure of surrounding area and humans to toxicants’ (including dioxins) from some components of MSW. We investigated the ecotoxicological situation outside the sanitary zone of the landfill “Salariyevo” (Moscow) closed and remediated in 2007.

The effect of the wire diameter and tensile and torsion loads on the remagnetization ability and the stress sensitivity of amorphous Co-alloy wires is investigated. It is shown that amorphous wires have a high magnetic softness to the applied external field in a wide range of diameters of 20–300 μm. The amplitude of the electromagnetic signal of electromotive force (EMF) increases with increasing wire diameter. It is established that amorphous wires with diameter in the range of 50–140 μm are sensitive to applied elastic tensile stresses. Increase in stresses to 300 MPa is accompanied by a fourfold decrease in the amplitude of the EMF signal. These wires are also sensitive to torsion stresses in a weakly and strongly stretched state. The first stage is accompanied by an intense increase in the amplitude of the EMF signal to values near to the amplitude of the original unloaded wire. At the second stage, the amplitude value achieved is preserved. It is established that an optimum interval of recording torsion stresses is determined by the wire diameter and values of applied tensile load. It is concluded that amorphous wires in a wide range of diameters can be used as highly sensitive noncontact sensors of field and tensile and torsion load detectors.

Abstract—The bending-deformation behavior of rapidly quenched Co69Fe4Cr4Si12B11 alloy wires 0.1–1 mm in diameter, which are fabricated by the Ulitovskii–Taylor method, are studied. A correlation between the failure mechanism of a wire and its diameter and bending loading conditions is shown. It is found that wires up to 0.2 mm in diameter exhibit no bending failure. The wedge-type fracture is observed for wires 0.2–0.35 mm in diameter; wires more that 0.35 mm in diameter exhibit steplike fracture. The wedge-type fracture, a dense regular shear-band network, and vein- and corallike fracture are shown to correspond to the 100% amorphous state of wires. This combination of signs is observed for wires up to 0.4 mm in diameter.

The changes of local atomic structure of amorphous magnetically soft iron-based Fe50Ni33B17, Fe54Ni29B17, Fe58Ni25B17, and Fe75Si8B17 alloys have been studied upon high-pressure torsion (HPT) at 77 K and 293 K. The set of structure research methods used for the study included EXAFS spectroscopy in synchrotron radiation, X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The effect of HPT regimes on the character of the local atomic environment of iron and nickel atoms has been established. The magnetic properties of the alloys were measured with a vibration magnetometer at room temperature. The correlation between the specific saturation magnetization and the parameters of the local atomic structure has been revealed. It is shown that the amorphous state after HPT is characterized by a significant change in the saturation magnetization and coercive force relative to those of the initial state. (C) 2019 Elsevier B.V. All rights reserved.

The principal aim of this study was to evaluate the effect of the electromechanical treatment (EMT) on the elastic properties of the air plasma sprayed coating from Ni powder. During the EMT process the boundaries of the splats welded and the quantity of the pores decreased from 8.0 ± 1.5% to 2.5 ± 0.5%, thus the elastic modulus of the coating increased from 63 ± 5 GPa to 95 ± 5 GPa. The obtained results revealed the high potential of the EMT for post-treatment of the plasma sprayed coatings.

The structure, phase composition, and C, O, and N content in two cermet coatings sprayed from powders of the initial composition of 30SiC–NiCr and 30SiC–TiNi are studied. The change in the chemical and phase composition is monitored at the stage of obtaining powders and plasma spraying of the coatings. The powder is obtained by mechanical alloying and subsequent sintering of the compact. With mechanical alloying, the content of oxygen and nitrogen increases. When sintering, the content of silicon carbide is reduced by 10 times, silicides are formed, and the content of light elements at this stage changes insignificantly. After plasma deposition, the phase composition of the coatings does not qualitatively change with respect to the powder to be sprayed, but nonequilibrium crystalline and amorphous phases are formed and the content of carbon and oxygen decreases. The microhardness of coatings of 10 GPa at load on an indenter of 10 g is determined by 50% of the volume fraction of SiC in the initial powder.

Results are presented from investigating the structural and magnetic characteristics of Co 69 Fe 4 Cr 4 Si 12 B 11 amorphous microwires with magnetic core diameters of 35–360 µm, obtained using an updated Ulitovskii–Taylor approach. It is found that the microwires have stable geometric dimensions along their lengths and almost defect-free surfaces. They are characterized by high plasticity and strength, and their magnetic characteristics depend on their diameter. The possibility of the microwires’ practical application is shown.

Аннотация - Данные собственных многолетних исследований эколого-зависимой патологии, возникшей у населения Вьетнама в местах применения армией США c 1962 по 1971 гг. смеси «Оранжевый агент», содержащей диоксины, систематизированы и применены при рассмотрении проблем токсикометрии малых доз диоксинов, загрязняющих среду в России. Результаты этих исследований апробированы на модели скрининговой оценки риска для здоровья населения диоксинов, загрязняющих среду селитебных зон в окрестностях свалки «Саларьево» в Новой Москве. Научная значимость работы отвечает задаче преодоления так называемых больших вызовов, принятых в качестве стратегического ориентира научно-технического развития Российской Федерации. Abstract - The data obtained by the authors in their own long-term investigations of an ecologically-dependent pathology emerged among the population of Vietnam as a result of applying dioxin-contaminated Agent Orange by the US Army between 1962 and 1971, were systematized and used for addressing a problem of low dose toxicometry of dioxins and their prolonged chronic effects on mammals and humans. The prospects for extending the above scientific research data to public health hazards in Russia were demonstrated in screening evaluation study of an ecotoxicological situation observed in the residential areas located in the vicinity of a municipal solid waste landfill (Salariyevo, New Moscow). These data provide a basis for creating a new approach for identifying disadvantaged areas polluted with dioxins. The scientific relevance of the studies is consistent with a task of overcoming the so-termed big challenges taken as strategic guidelines for scientific and technological development of the Russian Federation.

The mechanism of formation and propagation of shear bands on the surface of a model Co 69 Fe 4 Cr 4 Si 12 B 11 alloy amorphous wire 90 μm in diameter without a glass cover, which was subjected to different types of loading, such as uniaxial tension, drawing, bending, and torsion, is studied. For all applied loadings, the wire exhibits the ability to forming at a retained amorphous state. Depending on the type of loading, deformation is distributed either uniformly along the wire or is localized in a stress concentration zone. In this case, the contributions of forming mechanisms, namely, elastic deformation, ductile flow in the volume, and formation of shear bands on the wire surface, change. The wire is concluded to exhibit the pseudoplasticity effect.

The effect of the deformation temperature (293 and 77K) by high-pressure torsion (HPT) on the atomic structure of melt-quenched amorphous Fe83−xNiхB17 alloys (х=25, 29, 33) and their crystallization thermal effect upon continuous heating have been analyzed by method of Extended X-Ray Absorption Fine Structure (EXAFS) in synchrotron radiation, transmission electron microscopy, and X-ray diffraction analysis. HPT at 293K decreases the crystallization thermal effect, whereas HPT at 77K increases it regardless of the alloy composition. The observed effect is caused by the reversibility of the structural transformations in the alloys upon variation in the deformation temperature. According to the results of the structure examination, HPT at 293K leads to the formation of more ordered state (partially crystallized) of the initial amorphous alloys. On the contrary, HPT at 77K stimulates the formation of more disordered amorphous structure (by destruction of short-range order and an increase in the average values of the coordination numbers around the iron atoms in the first coordination sphere).