The main scenarios of nonequilibrium diffusional transformations induced by moving defects (dislocations, grain boundaries) in alloys under severe plastic deformation are considered. It has been shown that the phase state locally changes in the area of a defect where thermodynamic properties of alloy are locally changed, and the attained state is frozen after the displacement of a defect due to the difference between the rates of bulk diffusion and diffusion on a defect. For this reason, an alloy shifts from the state of its thermodynamic equilibrium under treatment, thus different nonequilibrium states, such as the disordering of alloy, the dissolution of equilibrium phase precipitates, the appearance of nonequilibrium phases, and the formation of regular structures, are possible depending on the type of the system. These effects may take place if the treatment of an alloy is performed at moderate temperatures, when diffusion is frozen in the bulk and rather active on defects. The phenomena of phase and structural instability developing under severe plastic deformation at moderate temperatures are considered within the framework of the proposed model.

AbstractThe absorption spectra of cobalt-doped anatase TiO_2 nanopowders in the infrared and visible ranges have been studied after various oxidative and reductive treatments. The annealing leads to the appearance of the Drude-like contribution in the infrared region and significant change in the absorption in an visible range due to the formation of defects of the oxygen-vacancy-type and Ti^3+ ions. The observed additional contribution in the absorption spectra of TiO_2:Co nanopowders as compared to the spectra of undoped powders is ascribed to the d – d transitions in ions Co^2+. The change in the absorption related to cobalt after annealing is explained by a change in the local environment of Co ions from the octahedral to the tetrahedral environment.

Nanoparticles Co 3 C were prepared using solid-phase synthesis under high pressure. The phase composition of the nanoparticles has been analyzed; the magnetization has been measured and 59 Со NMR spectra in a local field have been recorded. It is shown that Co 3 C is a ferromagnet with the Curie temperature T C = 498(10) K. The hyperfine fields and components of electric field gradient tensor were determined for two nonequivalent Co positions in the carbide. The obtained hyperfine fields correspond to the spin state of Co ions S = 1.

Nanoparticles Co3C were prepared using solid-phase synthesis under high pressure. The phase composition of the nanoparticles has been analyzed; the magnetization has been measured and 59Со NMR spectra in a local field have been recorded. It is shown that Co3C is a ferromagnet with the Curie temperature TC = 498(10) K. The hyperfine fields and components of electric field gradient tensor were determined for two nonequivalent Co positions in the carbide. The obtained hyperfine fields correspond to the spin state of Co ions S = 1.

Based on analyzing experimental data and existing theoretical approaches, this study has formulated concepts of regular change in scenarios of phase transformations developing under severe plastic deformation. Depending on the temperature and deformation conditions, the dissipation of delivered energy can be realized by various routes (dislocation glide and climb, dynamic recrystallization, amorphization, and redistribution of alloy components), giving rise to a diversity of observed phase and structural states. A diagram of nonequilibrium states of alloy as a function of conditions of severe plastic deformation has been proposed. The applicability of the presented concepts has been demonstrated for a wide range of alloys and compounds.

Abzymes with various catalytic activities are the earliest statistically significant markers of existing and developing autoimmune diseases (AIDs). Currently, schizophrenia (SCZD) is not considered to be a typical AID. It was demonstrated recently that antibodies from SCZD patients efficiently hydrolyze DNA and myelin basic protein. Here, we showed for the first time that autoantibodies from 35 SCZD patients efficiently hydrolyze RNA (cCMP > poly(C) > poly(A) > yeast RNA) and analyzed site-specific hydrolysis of microRNAs involved in the regulation of several genes in SCZD (miR-137, miR-9-5p, miR-219-2-3p, and miR-219a-5p). All four microRNAs were cleaved by IgG preparations (n = 21) from SCZD patients in a site-specific manner. The RNase activity of the abzymes correlated with SCZD clinical parameters. The data obtained showed that SCZD patients might display signs of typical autoimmune processes associated with impaired functioning of microRNAs resulting from their hydrolysis by the abzymes.

The magnetic properties of an oxygen-deficient nanocrystalline undoped titanium dioxide synthesized by the gas-phase, electric-explosion, and chemical method have been studied. The defect state was controlled using reduction treatments in vacuum or in a hydrogen atmosphere. It is shown that the defect state of the surface of nanocrystalline oxides (for example, the existence of vacancies in the anion sublattice and other defects) has a dominant influence on the formation of the magnetic properties of the samples under study. The main contributions to the magnetism of TiO2 nanoparticles after the reduction treatments are the paramagnetic contribution of the matrix, the paramagnetic Curie–Weiss contribution, and the contribution of the spontaneous magnetic moment provided by the existence of regions with different spin ordering. A heterogeneous magnetic state is found to exist in the TiO2 nanopowders; for example, at low temperatures, shifted hysteresis loops are observed as a result of a possible set of magnetic states with different spin orders. It is shown that a soft compaction or grinding of nanopowders in an agate mortar lead to substantial increase in the magnetization, sometimes, by a factor of more than two, regardless of the nanopowder synthesis method and the initial phase state of TiO2 (anatase or rutile structures). This experimental fact proves the key role of the surface defects and the magnetic moment carriers with different spin configurations localized mainly on the nanoparticle surface. The compaction changes the magnetization only in the case when the initial magnetic state has a nonlinear “quasi-superparamagnetic” character of the magnetization curve. As a result of predominant exchange interaction between the nanoparticles with a frustrated character of spin ordering on the nanoparticles surface, the ferromagnetic contribution increases as nanoparticles contact.

The magnetization of a series of Al 2 O 3 with different particle sizes and their 27 Al NMR spectra have been studied at room temperature. The field dependence of the magnetization demonstrated the existence of a long-range ferromagnetic order in a small part of the sample at room temperature; however, the relative volume of this contribution was very small (less than 1%), and this seems likely due to an impurity phase. The NMR spectra did not contain any lines of metallic aluminum the existence of which in these nanooxides was assumed before in a surface layer of the nanoparticles, according to the data of other techniques. The data on the phase composition and the charge distribution in different phases of the Al 2 O 3 nanoparticles have been obtained. The change in the mean particle size (by a factor of almost three) only insignificantly changed their phase composition.

Выполнены исследования магнитных свойств кислород-дефицитного нанокристаллического недопированного диоксида титана, синтезированного газофазным, электровзрывным и химическим методами. Дефектное состояние контролировалось с помощью восстановительных обработок в вакууме или в среде водорода. Показано, что дефектное состояние поверхности нанокристаллических оксидов (например, наличие вакансий по анионной подрешетке и других дефектов) оказывает доминирующее влияние на формирование магнитных свойств исследуемых образцов. Основные вклады в магнетизм наночастиц TiO2 после восстановительных обработок --- это парамагнитный вклад матрицы, парамагнитный вклад Кюри-Вейсса и вклад спонтанного магнитного момента, обусловленного существованием областей с различным спиновым порядком. Установлено существование гетерогенного магнитного состояния в нанопорошках TiO2; так при низкой температуре обнаружены смещенные петли гистерезиса, как результат возможного набора магнитных состояний с различным спиновым порядком. Показано, что мягкое компактирование или растирание нанопорошков в агатовой ступке, при котором увеличивается только доля контактирующих поверхностей нанопорошков, приводит к существенному росту намагниченности, иногда более чем в 2 раза, независимо от метода синтеза нанопорошков и исходного фазового состояния TiO2 (структура анатаза или рутила). Этот экспериментальный факт доказывает ключевую роль поверхностных дефектов и носителей магнитного момента с различными спиновыми конфигурациями, локализованных в основном на поверхности наночастиц. Изменение намагниченности при компактировании наблюдается только в том случае, когда исходное магнитное состояние имеет нелинейный "квазисуперпарамагнитный" характер кривой намагничивания. В результате, преимущественно, обменного взаимодействия между наночастицами с фрустрированным характером спинового упорядочения на поверхности наночастиц усиливается ферромагнитный вклад при их контакте. Выражаем благодарность Российскому научному фонду за финансовую поддержку исследований (грант N 16-12-10004). Электронно-микроскопические исследования проводились в ЦКП ОЭМ ИФМ УрО РАН. DOI: 10.21883/FTT.2017.03.44154.324

Измерена намагниченность при комнатной температуре, получены спектры ЯМР 27Аl в серии наночастиц Al2O3 c разным размером частицы. Полевая зависимость намагниченности свидетельствует о наличии у небольшой части образца дальнего ферромагнитного порядка при комнатной температуре, однако относительный объем этого вклада очень мал (меньше 1%) и, вероятно, это связано с примесной фазой. В спектрах ЯМР отсутствует линия от металлического алюминия, наличие которого в этих нанооксидах ранее предполагалось в поверхностном слое наночастиц по данным других методик. Получены данные о фазовом составе и зарядовом распределении в различных фазах наночастиц Al2O3. Изменение среднего размера частиц (в ~3 раза) лишь незначительно изменяет их фазовый состав. Работа выполнена в рамках государственной программы, тема "Спин" N 01201463330 с финансовой поддержкой по проектам РФФИ N 16-02-00416 и 14-02-00032. Измерения намагниченности выполнены в рамках темы "Магнит" N 01201463228. DOI: 10.21883/FTT.2017.03.44160.309

OBJECTIVETo study the correlations between the level of antibodies to native and denatured DNA and psychopathological symptoms and illness duration in patients with schizophrenia.MATERIAL AND METHODSThe level of antibodies to native (double-stranded) DNA and denatured (single-stranded) DNA was studied in the serum of 50 patients with schizophrenia, including 12 patients with tardive dyskinesia (TD). The control group consisted of 30 people.RESULTSA significant twofold increase in antibodies to native DNA was detected in patients with TD. There was no correlation of the amount of antibodies to double-stranded DNA with the duration of disease and leading symptoms both between the groups of patients as well as in comparison with controls. A significant decrease in antibody levels to the denatured (single-stranded) DNA was found in schizophrenic patients compared to the control group (p=0.009). A significant decrease in the concentration of antibodies to single-stranded DNA in patients with increasing duration of the disease, as well as in patients with leading negative symptoms was revealed.CONCLUSIONThe results suggest that anti-DNAantibodies may not play a major role in the pathogenesis of schizophrenia.

The distribution of iron-carbon nanoparticles in FeC-DSPE-PEG-2000 modification (micellar particles with structure (Fe) core-carbon shell; PEG-based coating) is studied. The greater part of the nanoparticles accumulated in the spleen and liver, a small amount in the lungs, and the minimum amount in the thymus. The structural changes in the lymphoid organs were minor and involved only the microcirculatory bed. Analysis of the peripheral blood showed manifest anemia, thrombocytopenia, and leukocytosis.

We studied new magnetic nanocomposites consisting of a core(Fe) and carbon-shell inert to biological media. Iron-carbon nanoparticles circulate in the bloodstream for several minutes and are primarily accumulated in the liver; less intensive accumulation was found in the spleen and minimum in the lungs, kidneys, and heart. Accumulation of nanoparticles in the liver leads to the development of destructive processes and is accompanied by activation of compensatory-adaptive mechanisms. In the liver and spleen, structural changes are mild and mainly relate to changes in the microvasculature. In 6 months, the total content of nanoparticles in all tissues decreased due to their elimination from the body and the structure of the organs returned to normal.

Oxidation stability and etch resistance of iron-carbon nanocomposite produced by gas-condensation method is investigated. To modify composite structure vacuum annealing at (200-1100) °С is used. It is shown that the vacuum heat treatment of Fe@C nanocomposites at (500-700) °С leads to both worsening of chemical stability (acid etching) and decreasing intensive oxidation temperature of nanocomposite at heating in air. On the contrary, annealing of Fe@C at high temperature (1000-1100)°С in vacuum improves the quality of carbon coating and enhances the oxidation stability of Fe@C composite.

The possibility of using iron oxide(III) nanoparticles covered with photoactive derivative of zinc phthalocyanine for diagnostics and treatment of malignant tumors was studied experimentally.

The composition and electronic structure of carbon-encapsulated iron nanoparticles Fe@C are examined by X-ray photoelectron, X-ray absorption, and resonant emission spectroscopy methods. It is found that the core in the Fe@C nanocomposite is in the metallic state with an impurity of iron carbide, which is preserved for two years. Experimentally measured spectra are compared to the calculations of the electronic structure of graphene performed at the density functional theory level. It is revealed that the Fe@C carbon shell can be presented as several graphene layers with Stone-Wales topological defects. Based on the measurements of X-ray resonant emission Kα spectra of carbon, the energy band dispersion of the carbon shell of Fe@C nanoparticles is investigated and the manifestation of Stone-Wales defects in them is shown.