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An algorithm of channel joint equalization and demodulation of multicarrier signals with nonorthogonal frequency spacing (spectrally efficient frequency division multiplexing, SEFDM) is proposed. It is based on DFT (Discrete Fourier Transform) and BCJR (Bahl, Cocke, Jelinek and Raviv) algorithm adapted to work with frequency samples of received signal. The performance of proposed receiver is comparable with performance of classic OFDM-signal receivers.

We describe the formation of swift heavy ion tracks in polyethylene (PE) by combining the Monte Carlo code TREKIS, which models electronic excitation in nanometric proximity of the ion trajectory, with the molecular dynamics simulating a response of the atomic system to the excitation. The model predicts circular tracks in amorphous PE but elliptical ones in crystalline PE caused by preferential propagation of excitation along polymer chains during the cooling stage. The obtained track sizes and shapes agree well with the high-resolution transmission microscopy of tracks in PE with colorant. The velocity effect in PE is shown: the track parameters differ for ions with the same linear energy losses but different velocities. Graphical abstract

Etching kinetics of swift heavy ions (SHI) tracks in olivine is investigated in frame of experimentally verified numerical approach. The model takes into account variation of induced chemical reactivity of the material around the whole ion trajectory with the nanometric accuracy. This enables a quantitative description of wet chemical etching of SHI tracks of different lengths and orientations towards to the sample surface. It is demonstrated that two different modes of etching, governed by diffusion of etchant molecules and by their reaction with the material must be observed in experiments using techniques with different resolution thresholds. Applicability limits of the optical microscopy for detection of heavy ion parameters by measuring of the lengthwise etching rates of the ion track are discussed.

— Adhesion/decohesion processes on the surface of dense metallic diffusion membranes in direct contact with hydrogen have been studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. The elemental composition of the alloys has been determined to be (wt %) Pd 93 Y 7 , Pd 100 – х Pb х ( х = 5, 20), and Pd 94 Ru 6 . We have revealed Pb emission from the surface of the Pd 100 – х Pb х membranes and Pb adhesion to the surface of the Pd 93 Y 7 membranes. No adhesion of yttrium particles to the surface of the palladium–lead membranes has been detected. The surface of Pd 94 Ru 6 alloy has good stability to adhesion/decohesion processes.

Surface morphology features of dense palladium-based membrane filters are studied using atomic force microscopy and scanning electron microscopy methods. Elemental compositions of the filters are Pd 95 Pb 5 and Pd 93.5 In 6.0 Ru 0.5 (hereafter, numerical coefficients mean the composition in wt %). The thickness of the dense membrane filters is 50 and 70 µm, respectively. High-purity metal samples are obtained by methods of electric arc fusion in a protective atmosphere and cold rolling with intermediate vacuum annealing. There are differences in morphology of the filter surface due to the elemental composition of the alloys. Manifestations of cavitation in the form of µm-sized funnels are found upon palladium doping with lead, and there are no such funnels for palladium alloyed with indium and ruthenium. Differences in the surface roughness of the samples are revealed. Surface areas of different hardness are detected using atomic force microscopy in the lateral force contrast mode. The obtained results are important not only for the choice of material for the manufacture of membrane filters with improved performance characteristics but also for the development of the elemental composition of membrane filters in order to optimize their operation in high-tech modern technological processes.

In-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is 5–6%. Consequently, it is necessary to develop fundamentally novel drugs capable of reducing mortality in patients with acute myocardial infarction. Apelins could be the prototype for such drugs. Chronic administration of apelins mitigates adverse myocardial remodeling in animals with myocardial infarction or pressure overload. The cardioprotective effect of apelins is accompanied by blockage of the MPT pore, GSK-3β, and the activation of PI3-kinase, Akt, ERK1/2, NO-synthase, superoxide dismutase, glutathione peroxidase, matrix metalloproteinase, the epidermal growth factor receptor, Src kinase, the mitoKATP channel, guanylyl cyclase, phospholipase C, protein kinase C, the Na+/H+ exchanger, and the Na+/Ca2+ exchanger. The cardioprotective effect of apelins is associated with the inhibition of apoptosis and ferroptosis. Apelins stimulate the autophagy of cardiomyocytes. Synthetic apelin analogues are prospective compounds for the development of novel cardioprotective drugs.

Coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats in vivo , as well as total ischemia (45 min) of an isolated rat heart followed by reperfusion (30 min) were reproduced. The selective δ 2 -opioid receptor agonist deltorphin II (0.12 mg/kg and 152 nmol/liter) was administered intravenously 5 min before reperfusion in vivo or added to the perfusion solution at the beginning of reperfusion of the isolated heart. The peripheral opioid receptor antagonist naloxone methiodide and δ 2 -opioid receptor antagonist naltriben were used in doses of 5 and 0.3 mg/kg, respectively. It was found that the infarct-limiting effect of deltorphin II is associated with the activation of δ 2 -opioid receptors. We have demonstrated that deltorphin II can improve the recovery of the contractility of the isolated heart after total ischemia.

A hybrid multiscale model consisting of two coupled modules is used to study the effect of irradiation temperature on the kinetics of the formation of swift heavy ions tracks in silicon carbide (6 H -SiC). Excitation of the electronic and atomic subsystems of the material is simulated using the Monte Carlo TREKIS-3 code. The profile of energy transferred to the atomic lattice is used as the initial conditions for molecular-dynamics simulations (using the LAMMPS package) of structural changes in the material near the trajectory of the swift heavy ion. Using the example of Bi-ion irradiation with an energy of 710 MeV, it is found that increasing irradiation temperature leads to an increase in the energy density transferred to the lattice. This induces rapid disordering of the core structure of the track at timescales on the order of 0.25 ps. At irradiation temperatures below 1800 K, subsequent recrystallization of the amorphous region within the cooling track leads to complete restoration of the material structure. At temperatures above the threshold of 1800 K, mass transfer, determined by the ejection of dislocations from the track core, results in the formation of nanoscale voids with a diameter of approximately 3 nm along the ion trajectory. The simulation results are useful for assessing the radiation resistance of silicon carbide under extreme irradiation conditions and for formulating ideas and designing new experiments on high-temperature SiC irradiation.

— The effect of ion velocity in the synthesis of nanopores with a noncircular cross section by the etching tracks of swift heavy ions in olivine is studied. The developed atomistic model of the etching of olivine irradiated with swift heavy ions predicts the possibility of synthesizing nanopores with a noncircular cross section in it. The model consists of connected blocks that describe the sequential stages of track formation and etching. The TREKIS Monte Carlo model describes the initial electronic and lattice excitations in the nanoscale vicinity of the trajectory of an incident ion. These results are used as initial conditions for the molecular-dynamics simulation of structural changes along the ion trajectory. The obtained atomic coordinates after cooling of the structurally damaged region serve as the initial data for an original atomistic model of track etching in olivine. The results of application of the model demonstrate that it is possible to control the cross section of resulting nanopores by changing the orientation of the crystal relative to the direction of irradiation. The presented simulation results for Xe ions demonstrate that the size of the resulting pores depends on the velocity of the incident ion, and not only on its linear energy losses.