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The paper provides a detailed description of the numerical implementation of the transport scheme in the Earth's ionosphere three-dimensional dynamical model of the Institute of Numerical Mathematics (INMIM). The presented version of INM-IM model takes into account the global dynamical processes of ion transport and ambipolar diffusion in the altitude range between 100 and 500 km (corresponding to F region). Based upon the splitting method the model solves the equations of ambipolar diffusion on the first split step and incorporates specifically designed advective transport scheme on the second step. The accuracy of transport scheme implementation in the model has been investigated through analytical solutions. The stability of the numerical algorithm has been demonstrated even for cases when transport velocities approaching extreme values. [ABSTRACT FROM AUTHOR]

Nanometer-thin single-walled carbon nanotube (CNT) films collected from the aerosol chemical deposition reactors have gathered attention for their promising applications. Densification of these pristine films provides an important way to manipulate mechanical, electronic, and optical properties. To elucidate the underlying microstructural level restructuring, which is ultimately responsible for the change in properties, we perform large scale vector-based mesoscopic distinct element method simulations in conjunction with electron microscopy and spectroscopic ellipsometry characterization of pristine and densified films by drop-cast volatile liquid processing. Matching with the microscopy observations, pristine CNT films with a finite thickness are modeled as self-assembled CNT networks comprising entangled dendritic bundles with branches extending down to individual CNTs. Simulations of these films under uniaxial compression uncover a soft deformation regime extending up to an ∼75% strain. When removing the loads, the pre-compressed samples evolve into homogeneously densified films with thickness values depending on both the pre-compression level and the sample microstructure. The significant reduction in thickness is attributed to the underlying structural changes occurring at the 100 nm scale, including the zipping of the thinnest dendritic branches. [ABSTRACT FROM AUTHOR]

The problem of variational data assimilation for the INM RAS two-dimensional diffusion model of the Earth's ionosphere F region is considered. Total integral electron contents along given paths are used as observation data. The general statement of the problem in differential form is formulated, and its solvability is analyzed. Based on a regularized statement, an iterative algorithm for solving the assimilation problem is constructed, and its convergence is demonstrated. A finite-dimensional approximation is constructed, the numerical solution of the problem is implemented, and the stability and convergence of the difference scheme are proved. The quality of the reconstruction of electron concentration fields is examined in test numerical experiments. It is shown that a weakly perturbed solution is reconstructed with acceptable accuracy for both stationary and evolutionary statements in the case of vertical and slant integration paths. [ABSTRACT FROM AUTHOR]

State-of-the-art approaches for localization and mapping are based on local features in images. Along with these features, modern augmented and mixed-reality devices enable building a mesh of the surrounding space. Using this mesh map, we can solve the problem of cross-device localization. This approach is independent of the type of feature descriptors and SLAM used onboard the AR/MR device. The mesh could be reduced to the point cloud that only takes vertices. We analyzed and compared different point cloud registration methods applicable to the problem. In addition, we proposed a new pipeline Feature Inliers Graph Registration Approach (FIGRA) for the co-localization of AR/MR devices using point clouds. The comparative analysis of Go-ICP, Bayesian-ICP, FGR, Teaser++, and FIGRA shows that feature-based methods are more robust and faster than ICP-based methods. Through an in-depth comparison of the feature-based methods with the usual fast point feature histogram and the new weighted height image descriptor, we found that FIGRA has a better performance due to its effective graph-theoretic base. The proposed pipeline allows one to match point clouds in complex real scenarios with low overlap and sparse point density. [ABSTRACT FROM AUTHOR]

The sub- and picosecond optical response dynamics of the metal–dielectric metasurface based on gold nanospheres placed in a layer of bismuth-substituted yttrium iron garnet has been studied via the pump–probe femtosecond spectroscopy with time resolution. It is shown that the plasmon modes of the metasurface demonstrate bulk gold dynamics, while the observed relaxation of the polariton mode is slowed down by several picoseconds. The difference arise because of the detection of different processes at the wavelengths of the plasmon and polariton modes by the probe beam. [ABSTRACT FROM AUTHOR]

A new INM RAS global dynamical model of Earth's ionosphere F region (100–500 km), which takes into account plasma-chemical processes, ambipolar diffusion, and advective ion transport due to electromagnetic drifts and neutral wind is presented. The model includes parameterizations of polar electric fields induced by magnetospheric convection and simplified equatorial drifts considerations. The focus of the paper is directed on the description of specific methods developed and utilized in the ionospheric model. Key processes responsible for the formation of global ionospheric features are outlined and their representation in the model is evaluated. The main global ionospheric characteristic features, such as seasonal and diurnal cycles, the equatorial ionization anomaly (EIA), polar ionization caps and the main trough have been adequately reproduced based on this model. [ABSTRACT FROM AUTHOR]

Here, we show a generic approach to synthesis of oligomers which include modelling LC main chain polymers, LC side chain polymers or LC dendrimers. Four new families of LC oligomers derived from 1,6-hexamethylene diisocyanate and their di- or trimers (uretdione, biuret or isocyanurate) and ω-hydroxyalkylated cyanobiphenyls were prepared. Their mesomorphic and optical properties were investigated by differential scanning calorimetry and polarised optical microscopy. Mesomorphic properties were crucially impacted by the structure of the central core spacer (urethane, uretdione, biuret or isocyanurate). Stabilisation of the LC state of synthesised oligomers was attributed to the H-bonding interactions confirmed by FTIR spectra. [ABSTRACT FROM AUTHOR]

The Triple-Modular Redundancy (TMR) technique is one of the conventional approaches to provide reliable functioning of logic circuits. When using outsourcing, it is possible to inject a Trojan Circuit (TC) in the same line of each identical TMR module, and the TMR technique becomes vulnerable. It is necessary to withstand to vulnerability. One way of solving this problem is the application of two approximate logic circuits and one correct circuit that implements the proper functioning in the frame of the TMR technique. However, this approach, as a rule, generates an unprotected area in which a fault of one of the three circuits may be undetected. It is desirable to minimize this area. In this paper, approximate circuits are built based on deriving approximate systems of Boolean functions. These systems are then applied for an approximate circuit synthesis. The approach gives additional possibilities for cutting the unprotected area compared to the methods suggested before. Algorithms of deriving the approximate systems of the Boolean functions based on analysis of an irredundant system of sums of products (SoPs) describing the behavior of the correct circuit have been developed. The algorithm appreciating the size of the unprotected area is also given. [ABSTRACT FROM AUTHOR]

Oxide interfaces provide very intriguing phenomena, in particular a 2D electron gas (2DEG) emerging between robustly insulating perovskites. The 2DEG was detected in 2004 beneath polar LaAlO3 (LAO) epitaxially grown on TiO2‐terminated SrTiO3 (001) (STO). Herein, recent first‐principles studies of 2DEGs are reviewed. Using a Green function method, the family of the polar/nonpolar (001) interfaces: LAO/STO, LaFeO3/STO, and STO/KTaO3 is computed. In the context of 2DEG, one of two insulating perovskites, at least, must be polar. The effect of a polar/polar interface is modeled for LAO/KTaO3(001) and also for the (110) and (111) interfaces of LAO/STO. Starting from the defectless superlattice with its two differently terminated interfaces, we demonstrate that the 2DEG and 2D hole gas appear there, respectively, due to the presence of excessive electrons or holes. 2DEG is evaluated by its layer‐resolved density profile along [001], as well as the Fermi surface cross sections and effective masses, which are directly related to the transport properties. The effects of intermixed cations, their vacancies, and oxygen vacancies at each interface of LAO/STO are calculated. Finally, we show how to tune reversibly the 2DEG by changing the electronic balance at the LAO surface that mimics the effect of ionic liquid gating. [ABSTRACT FROM AUTHOR]

A coupled Earth's thermosohere-ionosphere global dynamics model (for altitudes of 90–500 km) is presented. This model is based on a three-dimensional thermospheric general circulation model and a dynamical model of the ionospheric F-layer, which takes into account plasma-chemical processes, ambipolar diffusion, and advective ion transport due to neutral wind. General upper atmosphere characteristics have adequately been reproduced and the thermosphere–ionosphere interaction has quantitatively been estimated based on this coupled model. The sensitivity of thermospheric characteristics to ionospheric parameters and the sensitivity of the electron-concentration field distribution in the ionospheric F-layer to thermospheric parameters have been studied within a specified diurnal cycle. [ABSTRACT FROM AUTHOR]

The paper deals with the problem of the equatorial ionization anomaly (EIA) modelling and its representation in the global dynamical models of Earth's ionosphere and thermosphere. A new version of the coupled thermosphere-ionosphere global dynamical model which reproduce the equatorial anomaly considerably well is presented. Key processes responsible for the EIA formation are outlined and their representation in the model is indicated. It was shown that the developed coupled thermosphere-ionosphere model with additional accounting of vertical electromagnetic drift at the equator realistically represents the EIA characteristics. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "High Spin Polarization in All-3d-Metallic Heusler Compounds: The Case of Fe2CrZ and Co2CrZ (Z=Sc, Ti, V)" published in the Journal of Physics D: Applied Physics in 2019. The correction addresses errors in the caption of figure 4 and the first paragraph of subsection 3.3. The errors are related to the representation of the bands and the number of electrons in the minority-spin states. The correction does not affect the final conclusions of the paper. [Extracted from the article]

Highlights • Analytical formula-based method for resonance frequency measurement. • Simple quartz crystal microbalance (QCM) using a fixed frequency drive. • Ultrafast QCM with sub-millisecond time resolution and low noise. • Validated against impedance analysis method for mass and viscous loading. Abstract A new method for determination of resonance frequency and dissipation of a mechanical oscillator is presented. Analytical expressions derived using the Butterworth-Van Dyke equivalent electrical circuit allow the determination of resonance frequency and dissipation directly from each impedance datapoint acquired at a fixed amplitude and frequency of drive, with no need for numerical fitting or measurement dead time unlike the conventional impedance or ring-down analysis methods. This enables an ultrahigh time resolution and superior noise performance with relatively simple instrumentation. Quantitative validations were carried out successfully against the impedance analysis method for inertial and viscous loading experiments on a 14.3 MHz quartz crystal resonator (QCR). Resonance frequency shifts associated with the transient processes of quick needle touches on a thiol self-assembled-monolayer functionalised QCR in liquid were measured with a time resolution of 112 μs, which is nearly two orders of magnitude better than the fastest reported quartz crystal microbalance. This simple and fast fixed frequency drive (FFD) based method for determination of resonance frequency and dissipation is potentially more easily multiplexable and implementable on a single silicon chip delivering economies of scale. [ABSTRACT FROM AUTHOR]

1 H spin-diffusion solid-state NMR, in combination with other techniques, was utilized to investigate the effect of molecular architecture, solubility parameter of hard and soft segments, and their length on the domain size, interphase thickness and degree of phase separation in polyurethane-ureas based on oligomeric 4,4′-diisicyanate diphenylmethane, methylene-bis-(2-chloroaniline) and polyols based on polyethylene oxide, polypropylene oxide and polybutadiene with different length. Polyurethane-ureas based on polyethylene oxide soft blocks did not form rigid domains as a result of absence of microphase separation. The domain sizes of the hard segments in polyurethane-ureas under study practically did not show any dependence on their composition, but interphase thicknesses are higher for systems based on polybutadiene soft blocks. This indicates that the degree of phase separation depends strongly not only on the binary thermodynamic interaction between hard and soft segments in polyurethane-ureas, but is also influenced by their molecular architectures in the experimental temperature range. [ABSTRACT FROM AUTHOR]

The paper describes a sensor for single-stranded DNA (ssDNA) biomarker based on anharmonic acoustic signals arising during hybridization with complementary thiolated ssDNA functionalised on the gold electrode of an electrochemical quartz crystal resonator. The steps of sensor preparation and hybridization are carried out in an electrochemical microfluidic flowcell. While the electrochemical impedance spectroscopy does not allow a definitive interpretation, the changes in resonance frequency and third Fourier harmonic current of the resonator on actuation at the fundamental mode indicate formation of a flexibly bound layer. The functionalization and hybridization steps monitored by the anharmonic detection technique (ADT) are described with a simple model based on Duffing nonlinear equation. [ABSTRACT FROM AUTHOR]

Microelectromechanical systems (MEMS) have enabled the development of a new generation of sensor platforms. Acoustic sensor operation in liquid, the native environment of biomolecules, causes, however, significant degradation of sensing performance due to viscous drag and relies on the availability of capture molecules to bind analytes of interest to the sensor surface. Here, we describe a strategy to interface MEMS sensors with microfluidic platforms through an aerosol spray. Our sensing platform comprises a microfluidic spray nozzle and a microcantilever array operated in dynamic mode within a closed loop oscillator. A solution containing the analyte is sprayed uniformly through picoliter droplets onto the microcantilever surface; the micrometer-scale drops evaporate rapidly and leave the solutes behind, adding to the mass of the cantilever. This sensing scheme results in a 50-fold increase in the quality factor compared to operation in liquid, yet allows the analytes to be introduced into the sensing system from a solution phase. It achieves a 370 femtogram limit of detection, and we demonstrate quantitative label-free analysis of inorganic salts and model proteins. These results demonstrate that the standard resolution limits of cantilever sensing in dynamic mode can be overcome with the integration of spray microfluidics with MEMS. [ABSTRACT FROM AUTHOR]

We apply the modern technique of approximation of multivariate functions – tensor train cross approximation – to the problem of the description of physical interactions between complex-shaped bodies in a context of computational nanomechanics. In this note we showcase one particular example – van der Waals interactions between two cylindrical bodies – relevant to modeling of carbon nanotube systems. The potential is viewed as a tensor (multidimensional table) which is represented in compact form with the help of tensor train decomposition. The described approach offers a universal solution for the description of van der Waals interactions between complex-shaped nanostructures and can be used within the framework of such systems of mesoscale modeling as recently emerged mesoscopic distinct element method (MDEM). [ABSTRACT FROM AUTHOR]

We studied the structural, electronic, and magnetic properties of a cubic perovskite BaFeO3-δ (0 ≤ δ ≤ 0.5) within the density-functional theory using a generalized gradient approximation (GGA) and a GGA + U method. According to our calculations, BaFeO3 in its stoichiometric cubic structure should be half-metallic and strongly ferromagnetic, with an extremely high Curie temperature (TC) of 700-900 K. However, such an estimate of TC disagrees with all available experiments, which report that TC of the BaFeO3 and undoped BaFeO3-δ films varies between 111 and 235 K, or, alternatively, that no ferromagnetic order was detected there. Fitting the calculated x-ray magnetic circular dichroism spectra to the experimental features seen for BaFeO3, we concluded that good agreement can be obtained when oxygen vacancies are included in our model. Thus, the relatively low TC measured in BaFeO3 can be explained by oxygen vacancies intrinsically present in the material. Since iron species near the O vacancy change their oxidation state from 4+ to 3+, the interaction between Fe4+ and Fe3+, which is antiferromagnetic, weakens the effective magnetic interaction in the system, which is predominantly ferromagnetic. With increasing S in BaFeO3-δ, its TC decreases down to the critical value when the magnetic order becomes antiferromagnetic. Our calculations of the electronic structure of BaFeO3-δ illustrate how the ferromagnetism originates and also how one can keep this cubic perovskite robustly ferromagnetic far above room temperature. [ABSTRACT FROM AUTHOR]

Thegeometry and internal packing of twisted ropes composed ofcarbon nanotubes (CNTs) are considered, and a numerical solution inthe context of the mesoscopic distinct element method (MDEM) is proposed.Compared to the state of the art, MDEM accounts in a computationallytractable manner for both the deformation of the fiber and the distributedvan der Waals cohesive energy between fibers. These features enableus to investigate the torsional response in a new regime where thetwisted rope develops packing rearrangements and aspect-ratio-dependentgeometric nonlinearities. MDEM emerges as a robust simulation methodfor studying twisted agglomerates comprising semiflexible nanofibers. [ABSTRACT FROM AUTHOR]

Spin-dependent electronic transport through multiferroic Co/PbTiO3/Co tunnel junctions is studied theoretically in view of the recent observation of an inverse TMR in Co/PbTiO3/LaSrMnO3 heterostructures. Conductances calculated within the Landauer-Büttiker formalism yield a four-conductance state characterized by sizable positive tunnel magnetoresistances (TMR) and tunnel electroresistances (TER). The conductances depend crucially on the details of the electronic structure at the interfaces. In particular, the spin polarization of the tunneling electronic states is affected by the hybridization of orbitals and the associated charge transfer at both interfaces. Digital doping of the PbTiO3 barrier with Zr impurities at the TiO2/Co2 interface removes the excessive metalization of the barrier and significantly enhances the TMR but is not sufficient to switch the TMR's sign. Our results indicate that the origin of the TMR inversion might be attributed to the magnetoelectrically active LaSrMnO3/PbZr0.2Ti0.8O3 interface. [ABSTRACT FROM AUTHOR]

A phenomenological model describing the change in the structural characteristics of loose zinc deposits obtained in pulsed current modes is presented. Comparison of experimental data on the structural properties of deposits with the results of model calculations indicates the adequacy of the model. To describe the features of the dendritic deposit growth and to determine the duration of the homogeneous structure formation in pulsed modes, the concept of critical thickness is introduced, at which a sharp change in the loose deposit density occurs. The dependence of the zinc deposit critical thickness on the pulse duty ratio under pulsed current modes is determined. The increasing of the pulse duty ratio leads to denser deposits with rounded dendrite shapes and fewer growth points, as compared with the deposit obtained in galvanostatic mode. [ABSTRACT FROM AUTHOR]

One of the important properties of physical systems is reliability.of their functioning, in particular, reliability of functioning of logical control components of the systems. A new approach to partially programmable circuit design that allows masking stuck-at faults at gate poles of logical circuits is considered. The logical circuit consists of gates. It is supposed that only one gate pole may be fault. There are reserved programmable blocks configurable logic blocks (CLBs) based on Look Up Table (LUT) technology that may mask the fault. First, the suggested approach in contrast to the well-known ones, allows masking any stuck-at fault rather than a part of them. Second, the approach is oriented to deriving more simple masking circuit from CLBs based on a compact description of incompletely specified functions of subcircuits. [ABSTRACT FROM AUTHOR]

Magnetoelectric coupling at the interface between PbTi(Zr)O3 (001) (PZT) and a Co film as well as its tuning by Zr substitutions is studied here from first principles. Chemically disordered 25% Zr-doped compositions were modeled within the supercell approach. Our calculations suggest that ferroelectric ionic displacements in PZT can be locally enhanced, especially when the interfacial Ti cations are replaced with Zr. Regarding Co films their structure tends to become hexagonal for thicker films, while rather significant changes in Co magnetization are anticipated in response to the electric polarization reversal in PZT. [ABSTRACT FROM AUTHOR]

Despite advancements in analytical technologies, their complexity and cost have largely restricted their application in scalable online or multiplexed measurements. Here we report a quartz crystal resonator (QCR)-based method for detection of macromolecules that allows immensely simpler and faster measurements by employing for the first time a fixed frequency drive (FFD) and analytical expressions of acoustic parameters. Using human immunoglobulin E (hIgE) as an exemplar macromolecule and an anti-hIgE aptamer functionalised on a QCR, quantitative accuracy was benchmarked against the traditional impedance analysis method. The ability of FFD to capture data over longer observation periods at significantly higher acquisition rates at a fixed amplitude showed improvement in the QCR's sensitivity and specificity of transduction. The foundations for low-cost and low-power online integration and large-scale multiplexability are also discussed. • Analytical expressions for acoustic shift measurement. • Simpler quartz crystal microbalance (QCM) using a fixed frequency drive. • Ultrafast QCM with sub-millisecond time resolution. • Ultralow baseline noise, higher transduction sensitivity and specificity. • Promising for online integration and large-scale multiplexability. [ABSTRACT FROM AUTHOR]

Combining mesoscale distinct element method simulations with analytical modeling, we predict the ability of individual single-wall carbon nanotubes to form stable ring windings with multiple turns, in spite of their remarkable stiffness. The stability of these structures arises from the energy balance between the bending strain energy stored in the covalent bonds and the long-ranged van der Waals attraction along the turns. The significant energy density achieved in the ring windings made out of ultralong carbon nanotubes makes these architectures interesting for energy storage applications. [ABSTRACT FROM AUTHOR]

Magnetoelectric coupling has attracted interest due to its potential to write magnetic information with electric fields. In the model system of Fe islands on Cu(111), electric fields can induce martensitic phase transitions between ferromagnetic body-centered cubic and antiferromagnetic face-centered cubic phases. Here, we present a detailed study of the dynamics and energetics of the phase transition in the electric field of the junction of a scanning tunneling microscope. Statistical measurements allow us to reveal the influence of both the electric field and the crystallographic strain on the energy landscape of the two competing phases. [ABSTRACT FROM AUTHOR]

Consideration was given to the problem of time verification of the combinational circuits, namely, to the problem of determining the false paths. The delays arising in the false paths do not manifest themselves in the circuit operational mode. At determination of the maximal circuit delay as a whole it is recommendable to detect and disregard such paths. It was proposed to reduce the problem of detecting a false path to the search of a test pattern for the stuck-at 0.1 faults of the character of the equivalent normal form corresponding to this path. Search of the test patterns comes to analyzing the conjunctions of the equivalent normal form represented compactly by the AND-OR trees and the structurally synthesized binary decision diagrams. The joint analysis of the AND-OR trees and such diagrams was oriented to reducing the computer burden at seeking the test patterns. [ABSTRACT FROM AUTHOR]

The effect of electron-impurity scattering on momentum and spin relaxation times in graphene is studied by means of relativistic ab initio calculations. Assuming carbon and silicon adatoms as natural impurities in graphene, we are able to simulate fast spin relaxation observed experimentally. We investigate the dependence of the relaxation times on the impurity position and demonstrate that C or Si adatoms act as real-space spin hot spots inducing spin-flip rates about 5 orders of magnitude larger than those of in-plane impurities. This fact confirms the hypothesis that the adatom-induced spin-orbit coupling leads to fast spin relaxation in graphene. [ABSTRACT FROM AUTHOR]

The coherent potential approximation has historically allowed the efficient study of disorder effects over a variety of solid state systems. Its original formulation is, however, limited to a single-site or uncorrelated model of local substitutions. This neglects the effects of correlation and short-range ordering, often found in real materials. Recent theoretical work has shown one possible way to systematically address such shortcomings for simple materials with only one element per unit cell. We briefly review the basic ideas of such development within the framework of multiple scattering theory and suggest its generalization to materials with complex lattices. We validate our extension through a systematic comparison with a classic Cu1-cZnc reference test case and propose, for further illustration of local environment effects, the example of the yttria-stabilized cubic phase of zirconia, re-examined through various techniques for the first-principles treatment of disorder. [ABSTRACT FROM AUTHOR]

Abstract: The quartz crystal resonator has been traditionally employed in studying surface-confined physisorbed films and particles by measuring dissipation and frequency shifts. However, theoretical interpretation of the experimental observations is often challenged due to limited understanding of physical interaction mechanisms at the interfaces involved. Here we model a physisorbed interaction between particles and gold electrode surface of a quartz crystal and demonstrate how the nonlinear modulation of the electric response of the crystal due to the nonlinear interaction forces may be used to study the dynamics of the particles. In particular, we show that the graphs of the deviation in the third Fourier harmonic response versus oscillation amplitude provide important information about the onset, progress and nature of sliding of the particles. The graphs also present a signature of the surface–particle interaction and could be used to estimate the interaction energy profile. Interestingly, the insights gained from the model help to explain some of the experimental observations with physisorbed streptavidin-coated polystyrene microbeads on quartz resonators. [Copyright &y& Elsevier]

Abstract: We have developed a new method of controlling the pipette for scanning ion conductance microscopy to obtain high-resolution images faster. The method keeps the pipette close to the surface during a single line scan but does not follow the exact surface topography, which is calculated by using the ion current. Using an FPGA platform we demonstrate this new method on model test samples and then on live cells. This method will be particularly useful to follow changes occurring on relatively flat regions of the cell surface at high spatial and temporal resolutions. [Copyright &y& Elsevier]

Abstract: We investigated the influence of Panagen DNA preparations on laboratory animals and IFN-induced human dendritic cells, as well as analyzed the data from a phase II clinical trial in the therapy of breast cancer. It was shown that this treatment resulted in increased number of CD8+/perforin+ T cells in peripheral lymphoid organs of experimental animals, in mixed lymphocyte culture population and in peripheral blood of breast cancer patients. Moreover, we demonstrated that when Panagen DNA preparations are used in combination with the standard FAC-based breast cancer therapies, non-specific immune response activity remains at the same levels as observed prior to therapy, whereas in FAC-placebo patients, non-specific immunity is greatly diminished. [Copyright &y& Elsevier]

Magnetoelectric coupling allows for manipulating the magnetization by an external electric field or the electrical polarization by an external magnetic field. Here, we propose a mechanism to electrically induce 180° magnetization switching combining two effects: the magnetoelectric coupling at a multiferroic interface and magnetic interlayer exchange coupling. By means of first-principles methods, we investigate a ferroelectric layer in contact with a Fe/Au/Fe trilayer. The calculations show mat the interface magnetism is strongly coupled to the ferroelectric layer. Furthermore, under certain conditions a reversal of polarization causes a sign reversal of the interlayer exchange coupling which is results in a 180° switching of the free layer magnetization. We argue that this magnetoelectric coupling mechanism is very robust and can find applications in magnetic data storage. [ABSTRACT FROM AUTHOR]

Abstract: Receptor-based detection of pathogens often suffers from non-specific interactions, and as most detection techniques cannot distinguish between affinities of interactions, false positive responses remain a plaguing reality. Here, we report an anharmonic acoustic based method of detection that addresses the inherent weakness of current ligand dependant assays. Spores of Bacillus subtilis (Bacillus anthracis simulant) were immobilized on a thickness-shear mode AT-cut quartz crystal functionalized with anti-spore antibody and the sensor was driven by a pure sinusoidal oscillation at increasing amplitude. Biomolecular interaction forces between the coupled spores and the accelerating surface caused a nonlinear modulation of the acoustic response of the crystal. In particular, the deviation in the third harmonic of the transduced electrical response versus oscillation amplitude of the sensor (signal) was found to be significant. Signals from the specifically-bound spores were clearly distinguishable in shape from those of the physisorbed streptavidin-coated polystyrene microbeads. The analytical model presented here enables estimation of the biomolecular interaction forces from the measured response. Thus, probing biomolecular interaction forces using the described technique can quantitatively detect pathogens and distinguish specific from non-specific interactions, with potential applicability to rapid point-of-care detection. This also serves as a potential tool for rapid force-spectroscopy, affinity-based biomolecular screening and mapping of molecular interaction networks. [Copyright &y& Elsevier]

The electronic structure of (Zn,V)O dilute magnetic semiconductors (DMSs) was investigated theoretically from first principles, using the fully relativistic Dirac linear muffin-tin orbital band structure method and the Korringa-Kohn-Rostoker Green's function approach within the local spin-density approximation. X-ray magnetic circular dichroism (XMCD) spectra at the V L2,3 edges were calculated. Comparing the experimental results and the theoretical simulations we discuss possible crystal and magnetic structures of (Zn,V)O and reach the best agreement with the experimental XMCD spectra for the antiferromagnetically ordered DMSs in the presence of an oxygen vacancy. The corresponding structure was used to determine the electronic and magnetic properties of (Zn,V)O. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a sensitive and economical method to directly detect bacteria, based on the interaction between the bacteria and specific antibodies attached to an oscillating surface. By monotonously increasing the amplitude of oscillation of a quartz crystal microbalance (QCM) coated with the antibody, the QCM can be used to sensitively detect the acoustic noise produced when the interactions between the bacteria and the surface were broken. We term this process rupture event scanning (REVS). The method is quantitative over at least 6 orders of magnitude and can detect as few as 10 bacteria. We demonstrate here that this approach allows one to arrange separation of bacteria and follow the process completion on the basis of the acoustic signal. Detection is not significantly affected by non-specific binding of sample contaminants and thus can be achieved both in buffer and in serum. [Copyright &y& Elsevier]

We present a first-principles investigation of the electronic properties of Ge/Mn digital alloys obtained by the insertion of Mn monolayers in the Ge host. The main attention is devoted to the study of the magnetic properties of the Mn layers for various types of ordering of the Mn atoms. Depending on the type of Mn position three different structures are considered: substitutional, interstitial, and combined substitutional-interstitial. In all three cases numerical structural relaxation of the atomic positions has been performed. We find that the intralayer exchange parameters depend strongly on the crystal structure. For the substitutional and interstitial types of structure the stable magnetic order was found to be ferromagnetic. For the mixed substitutional-interstitial structure the ferromagnetic configuration appears unstable and a complex ferrimagnetic structure forms. The spin-wave excitations are calculated within the Heisenberg model. The critical temperatures of the magnetic phase transitions are determined using Monte Carlo simulations with interatomic exchange parameters obtained for two different magnetic reference states: a ferromagnetic and a disordered local moment state. [ABSTRACT FROM AUTHOR]

The acoustic response of conventional mechanical oscillators, such as a piezoelectric crystal, is predominantly harmonic at modest amplitudes. However, here, we observe from the electrical response that significant motional anharmonicity is introduced in the presence of attached analyte. Experiments were conducted with sireptavidin-coated polystyrene microbeads of various sizes attached to a quartz crystal resonator via specific and nonspecific molecular tethers in liquid. Quantitative analysis reveals that the deviation of odd Fourier harmonics of the response caused by introduction of microbeads as a function of oscillation amplitude presents a unique signature of the molecular tether. Hence, the described anharmonic detection technique (ADT) based on this function allows screening of biomolecules and provides an additional level of selectivity in receptor-based detection that is often associated with nonspecific interactions. We also propose methods to extract mechanical forceextension characteristics of the molecular tether and activation energy using this technique. [ABSTRACT FROM AUTHOR]

The challenges with frequency-based acoustic detection systems in sensitive, selective, and reliable quantitative estimation of surface-bound analyte are well-known. These systems are traditionally used in their linear incarnations; i.e., the measurement frequency is the same as the driving frequency. However, it was found in this work that interactions of adsorbents with sensor surface show significant anharmonicity even at low drive amplitudes. In particular, using streptavidin-coated polystyrene microbeads on an oscillating quartz surface in air, it has been demonstrated through modeling and experiments that the anharmonic signal from microparticle to surface interaction is significantly higher relative to that from bare quartz and orders of magnitude higher than relative shifts in resonant frequency. The signal is proportional to the number of microparticles and holds a well-defined functional relationship with the amplitude of oscillation, distinct to the nature of interaction with the surface for a given analyte. This approach, thus, can be used for ultrasensilive and quantitative detection of surface adsorbents and characterization of different kinds of surface interactions, distinguishing specific from nonspecific adsorbents. The modeling also reveals a direct functional relationship between the measured anharmonic signal and the interaction potential of the adsorbent with the surface. [ABSTRACT FROM AUTHOR]

Abstract: We present a first-principles study of the electronic and magnetic properties of cubic hafnium dioxide stabilized by Mn. We find this material to be ferromagnetic and half-metallic, with the Mn-impurity electronic states lying in the band gap of hafnia for a wide range of manganese concentration. Our ab initio calculations, within the local spin-density approximation, demonstrate that Mn-doped hafnia may be ferromagnetic at 700K while its high-T C ferromagnetism is robust to the oxygen vacancy defects and to how the Mn impurities are distributed over the cation sublattice. [Copyright &y& Elsevier]

We developed a new approach to evaluation of the intensity of osteogenic differentiation of mesenchymal stromal stem cells based on measurement of optical density of mesenchymal stromal cell cultures in a concentration range 625–10,000 cells per well after their culturing in osteogenic induction medium and staining of calcium deposits by the method of von Kossa. The proposed method allows comparative semiquantitative evaluation of osteogenic properties of mesenchymal stem cells depending on tissue sources (bone marrow, adipose tissue, placenta), in vitro cell density, number of passages, duration of culturing, and concentration of serum growth factors in the microenvironment. The developed approach makes it possible to compare functional activity of mesenchymal stromal cells in various pathologies. The proposed method can be used in traumatology and orthopedics for improving the efficiency of transplantation of mesenchymal stromal cells for stimulation of reparative osteogenesis. [ABSTRACT FROM AUTHOR]

Abstract: Microscopy is an essential technique for observation on living cells. There is currently great interest in applying scanning probe microscopy to image-living biological cells in their natural environment at the nanometer scale. Scanning ion conductance microscopy is a new form of scanning probe microscopy, which enables non-contact high-resolution imaging of living biological cells. Based on a scanned nanopipette in physiological buffer, the distance feedback control uses the ion current to control the distance between the pipette tip and the sample surface. However, this feedback control has difficulties over slopes on convoluted cell surfaces, which limits its resolution. In this study, we present an improved form of feedback control that removes the contribution of up to the third-order slope from the ion current signal, hence providing a more accurate signal for controlling the distance. We show that this allows faster and lower noise topographic high-resolution imaging. [Copyright &y& Elsevier]

Abstract  The levels of 17 cytokines in the follicular fluid were measured by multiplex proteome analysis at the peak of stimulated ovulation during the in vitro fertilization cycle. In patients with ineffective folliculogenesis, the concentrations of IL-2, IL-4, IL-7, and granulocytic CSF in the follicular fluid were significantly lower than in women with greater mean number of collected oocytes. It was shown that multicomponent cytokine deficit was associated with lower production of high quality oocytes and lower efficiency of fertilization of the resultant oocytes in vitro. The absence of pregnancy after in vitro fertilization cycle is associated with lower levels of IL-2, IL-4, IL-7, granulocytic CSF, and macrophagic inflammatory protein 1b in combination with elevated contents of IL-8 and IL-13. The results attest to an important role of cytokines in the regulation of oogenesis and in preparation of the endometrium to implantation of the embryo. [ABSTRACT FROM AUTHOR]

Disruption of the blood-brain barrier (BBB) and transendothelial migration of inflammatory cells are crucial steps in the development of demyelinating lesions in multiple sclerosis (MS). Occludin and vascular endothelial-cadherin (VE-cadherin) are two major components of the tight junctions (TJs) in the brain microvasculature that help to create the BBB. In the present study, we investigated the effect of serum from MS patients on the expression of these two junctional markers and on the endothelial integrity. Serum from six MS patients in exacerbation, six in remission, and six normal controls (10% by volume) was incubated with cultured endothelial cells, and the expression of occludin and VE-cadherin was measured by immunoblotting. Serum from MS patients in exacerbation significantly reduced the expression of occludin and VE-cadherin compared with patients in remission and normal controls. This disintegrating effect was more pronounced for occludin than for VE-cadherin. We assume that the elevation in cytokines or other serum-soluble factors in MS patients in exacerbation likely provokes downregulation of occludin and VE-cadherin. This downregulation of TJs proteins may, therefore, contribute to the disruption of the BBB in this condition. [ABSTRACT FROM AUTHOR]

It is strongly suspected that cytokine-induced gene expression in inflammation is oxidant mediated; however, the intracellular sources of signaling oxidants remain controversial. In inflammatory bowel disease (IBD) proinflammatory cytokines, such as TNF-α, trigger gene expression of endothelial adhesion molecules including mucosal addressin cell adhesion molecule-1 (MAdCAM-1). MAdCAM-1 plays an essential role in gut inflammation by governing the infiltration of leukocytes into the intestine. Several groups suggest that endothelial-derived reduced NADP (NADPH) oxidase produces signaling oxidants that control the expression of adhesion molecules (E-selectin, ICAM-1, VCAM-1). In addition to NADPH oxidase, cytochrome P-450 (CYP450) monooxygenases have also been shown to trigger cytokine responses. We found that in high endothelial venular cells (SVEC4-10), multiple inhibitors of CYP450 monooxygenases (SKF-525a, ketoconazole, troleandomycin, itraconazole) attenuated TNF-α induction of MAdCAM-1, whereas NADPH oxidase inhibition (PR-39) did not. Conversely, E-selectin, ICAM-1, and VCAM-1 induction requires both NADPH oxidase and CYP450-derived oxidants. We show here that MAdCAM-1 induction may depend exclusively on CYP450-derived oxidants, suggesting that CYP450 blockers might represent a possible novel therapeutic treatment for human IBD. [ABSTRACT FROM AUTHOR]

This study introduces a mathematical model to predict the dynamic angle of repose exhibited by granular materials in a rotating drum. The model accounts for the effect of particle properties, particularly sliding and rolling friction, as well as process conditions, i.e., the Froude number. We show that the effects of particle properties can be modeled independently of the process conditions, resulting in a multiplicative model. The model is validated using experimental data taken at different Froude numbers, yielding favorable agreement between the predicted dynamic angle of repose and the experimental observations. The findings of this study hold significant implications for engineering disciplines, as they provide crucial insights for optimizing processes involving granular materials in various engineering applications. [Display omitted] • We offered an analytical model for the dynamic angle of repose in a rotating drum. • We calibrated our model using discrete element simulations. • The model was validated using the lab-scale experiment. [ABSTRACT FROM AUTHOR]

Fabrication of nanostructured metasurfaces poses a significant technological and fundamental challenge. Despite developing novel material systems that support reversible elongation and distortion, their nanoscale patterning and control of optical properties remain an open problem. Herein we report the atomic force microscope lithography application for nanoscale patterning of single-walled carbon nanotube films and the associated optical reflection coefficient tuning. Large scale mesoscopic distinct element method atomic force nanoindentation simulations of single-walled carbon nanotube samples comprising entangled dendritic nanotube bundles with branches extending down to individual tubes explain the mesoscale mechanism of local irreversible densification and further predict its impact on mechanical properties. All observed and calculated phenomena support each other and present a platform for developing patterned optical devices using nanofibrous matter. [Display omitted] [ABSTRACT FROM AUTHOR]

• The temperature dependences of chemical shift of NH protons. • 2H solid state NMR of urea fragments. • Competition of electronic and geometrical factors on strength of H-bonds. We investigated the H-bonding behavior of urea compounds with different electronic nature of substituents and different spatial organization. Variable-temperature 1H NMR spectroscopy studies were performed in polar solvents which are capable (DMSO‑ d 6 and DMF-d7) or not (CDCl 3) to form the intermolecular hydrogen bonds and non-polar solvent (toluene- d 8) at the temperature range from 25 to 70 °C. Our results indicates that in the investigated systems the geometrical factors dominated over electronic effects of substituents at formation of intra- and intermolecular H-bonds. By the reaction between isocyanate and heavy water was synthesized the polymers with selectively deuterated urea groups and recorded their high-resolution solid-state 2H NMR spectra and measured their 2H quadrupole interaction parameters (i.e., the quadrupole coupling constant χ and asymmetry parameter η). Quite unexpectedly, the intermolecular hydrogen bonds are weaker in phenyl based urea polymers than in their cyclohexane based counterparts. [ABSTRACT FROM AUTHOR]

Abstract: Donor-specific blood transfusion (DST) has been shown to effectively induce tolerance to certain allografts. In addition, it is well known that blockade of costimulatory signals reduces the ability of T cells to respond to alloantigens, prolonging allograft survival in some transplant models. We assessed the effects of single or multiple DSTs in the absence or presence of anti-CD28 monoclonal antibodies (mAbs) on graft function and host survival in rat liver transplantation (LTx). Fully MHC-mismatched adult male Dark Agouti (DA) and Lewis (LEW) rats were used as donors and recipients, respectively. Heparinized DA blood was administered to naïve LEW rats 7 days before LTx [DST(−7d)], 14 and 7 days before LTx [DST(1×2)], twice a week for 2 weeks prior to LTx [DST(2×2)] and once a week for 4 weeks prior to LTx [DST(1×4)]. For some experiments, two different monoclonal antibodies (mAb) to rat CD28 (JJ316 and JJ319) were administered in combination with some DST treatments. We found that DST administration induced a time- and dose-dependent increase in host survival. Treatment of LEW rats with JJ316 or JJ319 mAb alone failed to prolong graft survival over untreated rats; however, the combination of DST(1×2) with JJ316 or JJ319 mAb induced indefinite survival at 100 days following surgery. We found that this protective effect was associated with increased numbers of splenic CD4+CD45RC− but not CD4+CD25+foxp3+ T-cells in long-term survivors. Our data suggest that the combination of suboptimal DST with CD28 mAb induces donor-specific tolerance that correlates with enhanced numbers of regulatory T-cells. [Copyright &y& Elsevier]

Background/Objectives: The intranasal delivery of various neurotropic substances is considered a new attractive therapeutic approach for treating neuropathologies associated with neuroinflammation and altered regeneration. Specific language impairment (SLI) that arises as a result of damage to the cortical speech zones during the developmental period is one of the most common problems in preschool children, and it is characterized by persistent difficulties in the acquisition, understanding, and use of language. This study's objective is to evaluate the efficacy and safety of intranasal immunotherapy using the M2 macrophage secretome as a rich source of immunoregulatory and neurotrophic factors for the treatment of severe language impairment in children. Methods: Seventy-one children (54 boys and 17 girls, aged 3 to 13 years) were recruited to participate in a clinical trial (NCT04689282) in two medical centers. The children were examined before, 1 month after, and 6 months after the start of therapy. In the vast majority of children (55/71), language impairment was associated with autistic-like symptoms and attention deficit hyperactivity disorder (ADHD). Results: Daily intranasal inhalations of M2 macrophage-conditioned medium (for 30 days) were well tolerated and led to a decrease in the severity of language impairments, autistic-like behavior, and ADHD symptoms. The clinical effect appeared within a month after the first procedure and persisted or intensified during a 6-month follow-up. Two-thirds of the children showed a clear clinical improvement, while the rest had less pronounced improvement. Conclusions: Thus, the use of the M2 macrophage secretome and its intranasal delivery is safe, well tolerated, and clinically effective in children with severe language impairments. [ABSTRACT FROM AUTHOR]