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A theoretical study is presented of the effect of an in-plane magnetic exchange field on the band structure of centrosymmetric films of noble metals and topological insulators. Based on an ab initio relativistic k ⋅ p theory, a minimal effective model is developed that describes two coupled copies of a Rashba or Dirac electronic system residing at the opposite surfaces of the film. The coupling leads to a structural gap at Γ ¯ and causes an exotic redistribution of the spin density in the film when the exchange field is introduced. We apply the model to a nineteen-layer Au(111) film and to a five-quintuple-layer Sb 2 Te 3 film. We demonstrate that at each film surface the exchange field induces spectrum distortions similar to those known for Rashba or Dirac surface states with an important difference due to the coupling: at some energies, one branch of the state loses its counterpart with the oppositely directed group velocity. This suggests that a large-angle electron scattering between the film surfaces through the interior of the film is dominant or even the only possible for such energies. The spin-density redistribution accompanying the loss of the counterpart favors this scattering channel.

The quantum spin Hall insulators predicted ten years ago and now experimentally observed are instrumental for a break- through in nanoelectronics due to non-dissipative spin-polarized electron transport through their edges. For this transport to persist at normal conditions, the insulators should possess a sufficiently large band gap in a stable topological phase. Here, we theoretically show that quantum spin Hall insulators can be realized in ultra-thin films constructed from a trivial band insulator with strong spin-orbit coupling. The thinnest film with an inverted gap large enough for practical applications is a centrosymmetric sextuple layer built out of two inversely stacked non-centrosymmetric BiTeI trilayers. This nontrivial sextuple layer turns out to be the structure element of an artificially designed strong three-dimensional topological insulator Bi 2 Te 2 I 2 . We reveal general principles of how a topological insulator can be composed from the structure elements of the BiTe X family ( X  = I, Br, Cl), which opens new perspectives towards engineering of topological phases.

We studied the effect of graphene oxide (GO) nanoparticles on differentiation of human myeloid suppressor cells (MDSC) in an in vitro system. Separated mononuclear cells of healthy donors were induced with cytokines (IL-6 and GM-CSF) into the MDSC phenotype (both polymorphonuclear (PMN-MDSC) and monocyte (M-MDSC) subsets of these cells were taken into account). Pegylated GO nanoparticles (GO-PEG; mean size 569±14 nm, PEG content ~20%) were used. GO-PEG in low concentrations (2.5 and 5 μg/ml) increased the percentage of MDSC in cultures, but reduced their content in high concentration (10 μg/ml). After exposure to GO-PEG (2.5 and 5 μg/ml), the MDSC content increased at the expense of M-MDSC, while the level of PMN-MDSC did not change. The decrease in MDSC levels after exposure to high doses of GO-PEG (10 μg/ml) was due to a decrease in PMN-MDSC. Thus, GO-PEG nanoparticles can oppositely regulate differentiation of MDSC by inhibiting or stimulating differentiation of these cells depending on the concentration.

We studied the effect of graphene oxide nanoparticles on the differentiation of human dendritic cells and uptake of nanoparticles by these cells in vitro . The objects of the study were mononuclear cells from healthy donors induced into the phenotype of dendritic cells by cytokines (IL-6 and GM-CSF). We used graphene oxide nanoparticles of different sizes functionalized with linear or branched PEG (P-GO or bP-GO) in concentrations of 5 and 25 μg/ml. It was found that graphene oxide nanoparticles did not affect the viability and percentage of dendritic cells in the culture. However, P-GO nanoparticles (25 μg/ml) suppressed the expression of CD83 on the surface of dendritic cells in cultures, thereby suppressing cell differentiation. Dendritic cells internalized P-GO nanoparticles, particles in high concentration were more actively engulfed, but the size of the particles and the type of PEG did not affect the intensity of this process. In general, P-GO nanoparticles in a concentration of 25 μg/ml can regulate differentiation of dendritic cells by suppressing their maturation.

A two-level problem for electricity generation scheduling in the wholesale market environment is proposed. The lower level of the problem corresponds to System Operator's (SO) efforts to schedule generation and calculate local marginal prices (LMPs) on the basis of total production cost minimization. The upper level corresponds to the profit maximization of each Generating Company (GC) with true cost functions and true generation ranges. The lower level of the problem is represented as a Mathematical Program with Equilibrium Constraints (MPEC). The problem is deemed solved, when the Nash equilibrium point is reached among strategic producers. The two-level optimization problem is formulated and the method for its solving is developed. A numerical example of a 15-bus Electric Power System (EPS) with thermal and hydro power plants is used to test the applicability of the approaches. The efficiency of the proposed approach is shown in comparison with traditional methods.

The topic of this article is a discussion of the prospects for using methods of recycling and desalination of waters of various composition that allow the implementation of schemes for the reuse of water in various production processes, while reducing both the total water consumption and the value of the resources received. Recycling itself is seen as an integral part - the addition of a single scheme of water supply, including, including the desalination stage.

Spintronics, or spin electronics, is aimed at efficient control and manipulation of spin degrees of freedom in electron systems. To comply with demands of nowaday spintronics, the studies of electron systems hosting giant spin-orbit-split electron states have become one of the most important problems providing us with a basis for desirable spintronics devices. In construction of such devices, it is also tempting to involve graphene, which has attracted great attention because of its unique and remarkable electronic properties and was recognized as a viable replacement for silicon in electronics. In this case, a challenging goal is to lift spin degeneracy of graphene Dirac states. Here, we propose a novel pathway to achieve this goal by means of coupling of graphene and polar-substrate surface states with giant Rashba-type spin-splitting. We theoretically demonstrate it by constructing the graphene@BiTeCl system, which appears to possess spin-helical graphene Dirac states caused by the strong interaction of Dirac and Rashba electrons. We anticipate that our findings will stimulate rapid growth in theoretical and experimental investigations of graphene Dirac states with real spin-momentum locking, which can revolutionize the graphene spintronics and become a reliable base for prospective spintronics applications.

Hardware and software for surgical instrument navigation using stereo X-ray imaging were developed. The developed surgical stereo X-ray navigation system provides 3D imaging in the process of surgery or during diagnostic examination of deep-lying abnormal foci or structural abnormalities of organs and tissues. Application of the developed system makes it possible to reduce considerably the duration of surgery. The obtained 3D X-ray images are automatically processed to provide accurate real-time guidance of the medical instrument (i.e., adjustment of the penetration depth, position, and orientation of the instrument). The developed technique of stereo X-ray navigation can be used for purposes of upgrading medical X-ray equipment, such as C-arch (Arcoscope) surgical X-ray devices.

The aim of this work is to develop an ecologically safe energy efficient system of supplying water with production of light-water on the basis of a nuclear desalination complex with low-power reactors in order to solve the problem of water shortage, reduction of ecological load on the environment, and secure freshwater in regions where it is in short supply. A fundamentally new combined scheme of a water supply system with light-water produced on the basis of nuclear desalination and water circulation (recycling) using membrane and distillation methods is proposed. The system provides for maximum extraction of contaminants before the desalination stage by less expensive methods of purification, which decreases the load on desalination and makes it more efficient.

By the interaction of formaldehyde with mixtures of phenol, phenolphthalein, and phthalimidine-containing bisphenols in the presence of an acidic catalyst, new co-oligophenol formaldehyde novolacs and crosslinked copolymers based on them are produced. Their properties are studied.