Excitation of coherent second sound waves in a dense magnon gas.

Second sound is a quantum mechanical effect manifesting itself as a wave-like (in contrast with diffusion) heat transfer, or energy propagation, in a gas of quasi-particles. So far, this phenomenon has been observed only in an equilibrium gas of phonons existing in liquid/solid helium, or in dielectric crystals (Bi, NaF) at low temperatures. Here, we report observation of a room-temperature magnonic second sound, or a wave-like transport of both energy and spin angular momentum, in a quasi-equilibrium gas of magnons undergoing Bose-Einstein condensation (BEC) in a ferrite film.

Comparative Study of Electrochemical Sensors Based on Enzyme Immobilized into Polyelectrolyte Microcapsules and into Chitosan Gel.

The characteristics of an electrochemical biosensor based on a Prussian-blue screen-printed electrode containing glucose oxidase incorporated into polyelectrolyte microcapsules (PMC) are considered. PMC with the embedded enzyme were formed using sodium polystyrene sulfonate and poly(allylamine hydrochloride). The characteristics were compared with those of the enzyme immobilized in chitosan gel.

Can absence seizures be predicted by vigilance states?: Advanced analysis of sleep-wake states and spike-wave discharges' occurrence in rats.

Spike-wave discharges (SWDs) are the main manifestation of absence epilepsy. Their occurrence is dependent on the behavioral state, and they preferentially occur during unstable vigilance periods. The present study investigated whether the occurrence of SWDs can be predicted by the preceding behavioral state and whether this relationship is different between the light and the dark phases of the 24-h day.

Nanofocusing and deceleration of terahertz plasma waves in tapered metal-insulator-graphene heterostructure.

Nanofocusing and deceleration of terahertz plasma waves in tapered metal-insulator-graphene heterostructure is studied theoretically. It is shown that, choosing an appropriate value of taper length for given values of the taper angle and the Fermi energy in a doped or gated graphene, the plasma wave energy density value in the vicinity of the taper apex exceeds its value in the taper inlet cross-section by tens of percent in spite of the Drude losses in graphene. The plasma wave decelerates while moving toward taper apex and its energy velocity becomes several times smaller as compared to that in the taper inlet cross-section.

Bioelectrochemical Properties of Enzyme-Containing Multilayer Polyelectrolyte Microcapsules Modified with Multiwalled Carbon Nanotubes.

This work investigated changes in the biochemical parameters of multilayer membrane structures, emerging at their modification with multiwalled carbon nanotubes (MWCNTs). The structures were represented by polyelectrolyte microcapsules (PMCs) containing glucose oxidase (GOx). PMCs were made using sodium polystyrene sulfonate (polyanion) and poly(allylamine hydrochloride) (polycation).

Theory of Magnetic Domain Phases in Ferromagnetic Superconductors.

Recently discovered superconducting P-doped EuFe_{2}As_{2} compounds reveal the situation when the superconducting critical temperature substantially exceeds the ferromagnetic transition temperature. The main mechanism of the interplay between magnetism and superconductivity occurs to be an electromagnetic one, and a short-period magnetic domain structure was observed just below Curie temperature [V. S.

Guided acoustic waves at the intersection of interfaces and surfaces.

In numerical calculations, guided acoustic waves, localized in two spatial dimensions, have been shown to exist and their properties have been investigated in three different geometries, (i) a half-space consisting of two elastic media with a planar interface inclined to the common surface, (ii) a wedge made of two elastic media with a planar interface, and (iii) the free edge of an elastic layer between two quarter-spaces or two wedge-shaped pieces of a material with elastic properties and density differing from those of the intermediate layer. For the special case of Poisson media forming systems (i) and (ii), the existence ranges of these 1D guided waves in parameter space have been determined and found to strongly depend on the inclination angle between surface and interface in case (i) and the wedge angle in case (ii). In a system of type (ii) made of two materials with strong acoustic mismatch and in systems of type (iii), leaky waves have been found with a high degree of spatial localization of the associated displacements, although the two materials constituting these structures are isotropic.

Normal and pathological gait classification LSTM model.

Computer vision-based clinical gait analysis is the subject of permanent research. However, there are very few datasets publicly available; hence the comparison of existing methods between each other is not straightforward. Even if the test data are in an open access, existing databases contain very few test subjects and single modality measurements, which limit their usage.

Sensor for ampicillin based on a microwave electrodynamic resonator.

The paper describes a new biological sensor which represents a resonator based on a segment of a rectangular waveguide of 8 GHz band with shear dimensions of 28.5 × 12.6 mm.

The Brain Network in a Model of Thalamocortical Dysrhythmia.

Sensory information processing and higher cognitive functions rely on the interactions between thalamus and cortex. Many types of neurological and psychiatric disorders are accompanied or driven by alterations in the brain connectivity. In this study, putative changes in functional and effective corticocortical (CC), thalamocortical (TC), and corticothalamic (CT) connectivity during wakefulness and slow-wave sleep (SWS) in a model of thalamocortical dysrhythmia, TRIP8b mice, and in control (wild-type or WT) mice are described.

Exact equations for averaged electromagnetic field and its fluctuations at wave multiple scattering by plane periodic array of magnetic microelements.

Electromagnetic wave (EM) multiple scattering by a plane periodic array of magnetic microelements in free space is considered analytically by natural subdividing of the EM wave into the averaged and fluctuation components. Each magnetic element is characterized by magnetic susceptibility tensor and shape. An exact Dyson integral equation is derived for the magnetic field Floquet-Bloch amplitude in-plane averaged over an array unit cell.

Light-Tuned DC Conductance of Anatase TiO₂ Nanotubular Arrays: Features of Long-Range Charge Transport.

Experimental results related to the photoactivated dc conductance of anatase TiO₂ nanotubular arrays (aTNTAs) under pulsed irradiation by a laser light inside and outside the fundamental absorption band are presented. It is found that the mobility and diffusion coefficients of charge carriers in the examined aTNTA are extremely low due to a strong charge-phonon coupling, abundance of shallow traps, and hopping conductivity between adjacent nanotubes. We consider that the confining electric field appeared within the array structure due to the difference in the local concentrations of excess electrons and holes at large values of the dc conductance suppresses the drift current.

Effects of Polymer Matrices and Carbon Nanotubes on the Generation of Electric Energy in a Microbial Fuel Cell.

The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or -vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate.

The effect of the conductivity of a film located near a piezoelectric resonator with a lateral electric field based on the PZT ceramics on its characteristics.

In this paper, we investigated theoretically and experimentally the effect of the conductivity of the film located in the immediate vicinity of the free side of a piezoelectric resonator based on the PZT ceramics on its characteristics. It is shown that with increasing the conductivity of the film at first the parallel resonant frequency does not change, then it decreases in a certain interval and after that remains practically constant. With increasing the width of the gap between the film and the resonator, the resonant frequency increases and reaches the saturation.

Synchronization of infra-slow oscillations of brain potentials with respiration.

We study the synchronization of infra-slow oscillations in human scalp electroencephalogram signal with the respiratory signal. For the cases of paced respiration with a fixed frequency and linearly increasing frequency, we reveal the phase and frequency locking of infra-slow oscillations of brain potentials by respiration. It is shown that for different brain areas, the infra-slow oscillations and respiration can exhibit synchronous regimes of different orders.

[Application of brain electrical activity burst analysis method for detection of EEG characteristics in the early stage of Parkinson's disease].

Aim: To develop a mathematical method of analysis and visualization of EEG based on the ROC analysis of burst electrical activity in the cerebral cortex.

Material And Methods: Using a new method of analysis of EEG burst activity, the frequency parameters of brain electrical activity have been investigated in patients in the first stage of Parkinson's disease (PD) defined by the Hoehn and Yahr scale. Patients were right-handed, with disease onset in either the right or the left side.

Interaction between cardiovascular autonomic control and sex hormones in perimenopausal women under menopausal hormone therapy.

Objective: The aim of this study was to assess the dynamical interaction between the cardiovascular autonomic control and sex hormones in perimenopausal women under menopausal hormone therapy (MHT).

Patients And Methods: Seventy women (age: 51.6±2.

Effect of the conductivity of a thin film located near the acoustic delay line on the characteristics of propagating SH wave.

The results of the study of the influence of the conductivity of a thin film located with a certain gap above the acoustic delay line on the characteristics of propagating acoustic wave with a quasi-shear-horizontal polarization (SH) are presented. The delay line was made of Y-X lithium niobate plate with a thickness of 200 μm containing two interdigital transducers for exciting and receiving SH wave. The operating frequency range of the delay line was equal to 2.

Transient and equilibrium causal effects in coupled oscillators.

Two quite different types of causal effects are given by (i) changes in near future states of a driven system under changes in a current state of a driving system and (ii) changes in statistical characteristics of a driven system dynamics under changes in coupling parameters, e.g., under switching the coupling off.

Discrepancy between the European clinical guidelines and myocardial revascularization in patients with stable coronary artery disease in Russia.

Objective: In European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines, six indications have been proposed for making a decision on myocardial revascularization in patients with stable coronary artery disease (CAD). Our aim was to study a discrepancy between the actual clinical situation and ESC/EACTS indications on performing the revascularization in patients with CAD in Russia.

Design And Setting: We used retrospective clinical data on patients with stable CAD enrolled in the 2012-2015 Russian Registry of Hypertension, Coronary Artery Disease, and Chronic Heart Failure.

Analysis of the microbial cell-Ab binding in buffer solution by the piezoelectric resonator.

The possibility of the registration of the interaction of the cells Azospirillum lipoferum Sp59b with the specific antibodies directly in the conducting suspensions by using an acoustic sensor was shown. The main element of the sensor is a piezoelectric resonator with a lateral electric field. The analysis is based on a comparison of the resonator's electrical impedance before and after the specific biological interaction between the cells and antibodies.

Comparative study of short-term cardiovascular autonomic control in cardiac surgery patients who underwent coronary artery bypass grafting or correction of valvular heart disease.

Our aim was to perform a comparative study of short-term cardiovascular autonomic control in cardiac surgery patients who underwent coronary artery bypass grafting (CABG) or surgical correction of valvular heart disease (SCVHD ). The synchronous 15 minutes records of heart rate variability (HRV) and finger's photoplethysmographic waveform variability (PPGV) were performed in 42 cardiac surgery patients (12 women) aged 61.8 ± 8.

Influence of electrical boundary conditions on profiles of acoustic field and electric potential of shear-horizontal acoustic waves in potassium niobate plates.

The profiles of an acoustic field and electric potential of the forward and backward shear-horizontal (SH) acoustic waves of a higher order propagating in X-Y potassium niobate plate have been theoretically investigated. It has been shown that by changing electrical boundary conditions on a surface of piezoelectric plates, it is possible to change the distributions of an acoustic field and electric potential of the forward and backward acoustic waves. The dependencies of the distribution of a mechanical displacement and electrical potential over the plate thickness for electrically open and electrically shorted plates have been plotted.

Giant amplification of terahertz plasmons in a double-layer graphene.

The amplification of terahertz plasmons in a pair of parallel active graphene monolayers is studied theoretically. The plasmon wave in a symmetric double-layer graphene structure splits into two branches with a symmetric and an antisymmetric distribution of tangential to graphene component of the electric field across the plane of symmetry of the structure. It is shown that, normalized to the wavelength, the terahertz plasmon amplification factor of the symmetric mode in the double-layer graphene structure could be greater than that in a single graphene layer by four orders of magnitude.

Modeling spike-wave discharges by a complex network of neuronal oscillators.

Purpose: The organization of neural networks and the mechanisms, which generate the highly stereotypical for absence epilepsy spike-wave discharges (SWDs) is heavily debated. Here we describe such a model which can both reproduce the characteristics of SWDs and dynamics of coupling between brain regions, relying mainly on properties of hierarchically organized networks of a large number of neuronal oscillators.

Model: We used a two level mesoscale model.