bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Back-Scattering and Forward-Scattering Methods in Short Range Microwave Imaging Systems
Authors: Razevig V. V.  , Bugaev A. S.  , Ivashov S. I.
Published: March 2023

Microwave imaging technique allows obtaining images of hidden objects in structures and media using microwaves. Usually in short-range microwave imaging systems, the back-scattered signal is used, when a combined transmit-receive antenna scans over a plane, forming a two-dimensional synthesized aperture, while the signal reflected from the object of observation is recorded, as a result of which a microwave hologram of the object is formed. The second option involves registering the forward-scattered signal, when the transmitting and receiving antennas are located on opposite sides of the object and scan synchronously. The purpose of this work is a theoretical and experimental comparison of these two sounding options, identifying the advantages and disadvantages of each option, taking into account the features that arise when solving various problems of microwave imaging. Keywords: microwave holography, mivrowave image, back-scattered signal, forward-scattered signal, range resolution.
The temperature distribution simulation in the graphene sublimation growth zone on SiC substrate
Authors: Lebedev S. P.  , Priobrazhenskii S. Iu.  , Plotnikov A. V.  , Mynbaeva M. G.  , Lebedev A. A.
Published: March 2023

The simulation results of the temperature distribution in the growth area of graphene layers obtained by the method of thermal decomposition of the silicon carbide surface substrates in setup with induction heating are presented. The heating parametrs of the setup elements are calculated using the commercial package COMSOL Multiphysics taking into account the electrical, thermal and magnetic properties of the materials from which the growth plant elements are made. A numerical estimate of the heating inhomogeneity of silicon carbide plates over its area during the growth of graphene layers at a given temperature is given. It is shown that the lateral temperature distribution over the area of the plate has radial symmetry with decreasing values towards the center. Keywords: graphene, silicon carbide, simulation, temperature distribution, sublimation growth.
Rotational and translational galloping of prisms in the air stream
Authors: Ryabinin A. N.  , Bobu Yu. E.
Published: March 2023

In experiments in a wind tunnel, oscillations of three prisms with a rectangular cross section are studied. The prisms are located perpendicular to the velocity vector of the incoming flow and are limited from the ends by end plates that prevent air flow. The elastic suspension allows body oscillation with six degrees of freedom. It turned out that under the action of the air flow, two modes of oscillation of prism realized: translational oscillations in the direction perpendicular to the generatrix of prismatic bodies and the flow velocity, and rotational oscillations around an axis that is parallel to the generatrix, passes through the center of the prism and is perpendicular to the velocity of the incoming air flow. The tension of the two springs included in the elastic suspension is measured by the strain gauge method during the oscillation. The calibration experiment makes it possible to link the amplitudes of spring tension oscillations and phase shift with the amplitudes of rotational and translational oscillations of prisms. It turned out that a prism with a height-to-width ratio of 0.22 in the flow is subject to rotational oscillations. An increase in the ratio of height to width to 0.36 leads to a decrease in the amplitude of rotational oscillations and the appearance of translational ones. The ranges of existence of rotational and translational oscillations overlap. A further increase in the ratio of height to width to 0.43 is accompanied by intensive translational galloping. Keywords: galloping, bluff body, wind tunnel, strain gauge, translational oscillations, rotational oscillations.
Modeling of shock-wave loading of magnesium silicates on the example of forsterite
Authors: K K Maevskii
Published: March 2023

The results of modeling the shock-wave loading of Mg2SiO4 forsterite, which in this case is considered as a mixture of SiO2 quartz and MgO periclase, are presented. The model is based on the assumption that the components of the mixture under shock-wave loading are in thermodynamic equilibrium. The model allows us to reliably describe the phase transition region. The components of the investigated material are considered as a mixture of low and high pressure phases. Polymorphic phase transitions of quartz and periclase are taken into account in the calculation of forsterite in pressure range from 1 to 1000 GPa. The results are verified by experimental data obtained in dynamic experiments. Keywords: Equation of state, shock adiabat, thermodynamic equality, magnesium silicates, forsterite. DOI: 10.21883/0000000000
Power Source based on Al-=SUB=-0.8-=/SUB=-Ga-=SUB=-0.2-=/SUB=-As/GaAs photovoltaic converter and YPO-=SUB=-4-=/SUB=- : Eu/(-=SUP=-238-=/SUP=-Pu) radioluminescent emitter
Authors: Prudchenko K.K.  , Tolkachev I.A.  , Kontrosh E.V.  , Silantieva E.A.  , Kalinovskii V.S.
Published: March 2023

An AlGaAs/GaAs photovoltaic converter for a mock-up of an environmentally friendly radioisotope energy source of ultra-long use with a YPO4 : Eu/(238Pu) radioluminescent emitter with an extremely low content of the isotope 238Pu<0.1 wt.% was studied. The modeling of the Al0.8Ga0.2As/GaAs heterostructure for the conversion of nanowatt power levels of an optical signal has been carried out. The calculated and experimental efficiency of the mock-up with a photovoltaic converter at a radioluminescent source power of 1 nW was ~1.4%. Keywords: radioisotope energy source, AlGaAs/GaAs photo converter, optical radiation radioluminescent source, current flow mechanisms, conversion efficiency.
Zn-=SUB=-x-=/SUB=-Fe-=SUB=-3-x-=/SUB=-O-=SUB=-4-=/SUB=- (0 ≤ x≤ 1.0) magnetic nanoparticles functionalized with polyacrylic acid (PAA)
Authors: Kamzin A.S.  , Caliskan G.  , Dogan N.  , ab1353@gmail.com  , Semenov V. G  , Buryanenko I. V.
Published: March 2023

Studies of the properties of ZnxFe3-xO4 (x=0, 0.25, 0.5, 0.75, 1.0) magnetic nanoparticles synthesized by a modified hydrothermal method are presented in comparison with the properties of the same nanoparticles stabilized with polyacrylic acid ZnxFe3-xO4@PAA. The structure, size, morphology, and magnetic properties of the samples were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR), physical properties measurements (PPMS), and Mossbauer spectroscopy. The synthesized nanoparticles are single-phase, without additional impurities, have a narrow size distribution and are in the superparamagnetic phase. From the (XRD) measurements, it was found that with an increase in the Zn content from x=0 to x=1.0, the sizes of the nanoparticles were increasing from 17 to 33 nm. Analysis of the Mossbauer spectroscopy data showed that when doped with Zn ions from x=0 to x=1.0, the sizes of the nanoparticles were decreasing from 15 nm to 5 nm. The results of the Mossbauer studies showed that both ZnxFe3-xO4 and ZnxFe3-xO4@PAA has a core/shell type structure in which the core is magnetically ordered, whereas the shell does not have magnetic ordering. Mossbauer studies indicate that the coating of citric acid particles leads to their isolation from each other (i. e., a decrease in the thickness of the paramagnetic shell, and due to this to increasing in the diameter of the core). This (the last sentense) sentense is too long. It could be mode two or three sentences for better clarification. Keywords: ferrite-spinel nanoparticles, hydrothermal synthesis, polyacrylic acid functionalization, Mossbauer spectroscopy, properties, crystal and magnetic structure.
Scanning Kelvin Probe Microscopy investigation of optically induced charge in Au nanoparticles embedded into ZrO-=SUB=-2-=/SUB=-(Y) films
Authors: Filatov D.O.  , Novikov A. S.  , Shenina М. E.  , Antonov I. N.  , Nezhdanov A. V.  , Kazatseva I.A.  , Gorshkov O.N.
Published: March 2023

Accumulation and relaxation of optically induced electric charge in ZrO2(Y) films with embedded single-layered arrays of Au nanoparticles (NPs) of 2-3 nm in diameter have been studied subject to the depth of the Au NPs in the ZrO2(Y) layers and the optical excitation power at the wavelengths of 473 and 633 nm by Scanning Kelvin Probe Microscopy (SKPM). Keywords: thin film systems, zirconia, nanoparticles, plasmon resonance.
Physico-mechanical characteristics of biomaterial patches for numerical modeling problems
Authors: Onishchenko P. S.  , Glushkova T. V.  , Kostyunin A. E.  , Rezvova M. A.  , Barbarash L. S.
Published: March 2023

A full-scale study of the physical and mechanical properties of a number of samples of commercial biomaterials-patches was carried out. It is shown that all materials have a pronounced non-linearity of behavior, manifested in the presence of an initial gentle stress section with a subsequent increase in stiffness, however, there are quantitative differences in the length of these sections and, accordingly, in the final characteristics: tensile strength, elongation at break, elasticity. The results of numerical verification of the obtained coefficients of hyperelastic materials models showed high convergence with the results of field tests. Keywords: numerical modeling, physical and mechanical tests, hyperelastic material model, polynomial approximation.. Keywords: numerical simulation, physical and mechanical testing, hyperelastic material model, polynomial approximation.
Physical foundations of the formation of the silicon-based heterovarizonic structure
Authors: Bakhadirkhanov M. K.  , Isamov S. B.
Published: March 2023

With the formation of binary unit cells based on the AII and BVI, AIII and BV elements, a heterovarizonic structure was obtained in the near-surface region of silicon, without destroying the crystal structure, without surface states with a thickness of about 5 μm. The resulting heterovarizonic structure has special fundamental parameters that ensure the absorption of light in a wide range of the solar spectrum from UV to IR radiation with λ=0.1-3 μm, i.e., it covers the entire solar spectrum. Keywords: silicon, photocell, solar cell, heterovarizonic structure, photovoltaics, AIIBVI, AIII, BV compounds.
Changes in the characteristics of semiconductor structures of microwave amplifiers under the action of pulsed laser radiation
Authors: Pashentsev V. N.
Published: March 2023

The effect of pulsed laser radiation on the change in the parameters of semiconductor structures of field-effect transistors with a Schottky gate with an operating frequency range of 1.5-8 GHz and integrated amplifiers with an operating frequency range of 0.4-6 GHz is studied. Laser radiation with 25 ns pulse duration, incident on the transistor crystal, creates a pulsed photocurrent. It is shown that the amplitude of the pulsed photocurrent is three times higher than the operating transistor current. The current-voltage characteristics of the field-effect transistor were measured in the mode of pulsed laser radiation. The amplitude dependence of the pulsed photocurrent in semiconductor structures on the power of laser radiation for various wavelengths of 1.06 μm and 0.53 μm is studied. It is shown that as a result of the action of pulsed laser radiation on semiconductor structures, a short disappearance of the amplification of the high-frequency signal at the amplifier output occurs. Keywords: laser radiation, transistor, microwave amplifier, photocurrent, current-voltage characteristic.
Comparison of polarization fading compensation methods for broadband microwave photonic links by introduced noise and achievable dynamic range
Authors: Lebedev V.V.  , Petrov A.N.  , Parfenov M.V.  , Velichko E.N.  , Shamray A.V.
Published: March 2023

Two methods for compensation of polarization fading in microwave photonic links have been studied. Comparison of noise characteristics has been performed and factors limiting the dynamic range of microwave photonic link have been analyzed on an example of a link with an external remote electrooptic modulator. The possibility of reaching spurious-free dynamic range close to the shot-noise limit SFDR3~116 dB Hz-2/3 has been demonstrated for 1000 m microwave photonic link. Keywords: Optical polarization, polarization fading, fiber-optic links, optical noise, dynamic range, balanced detection, microwave photonics, integrated optical modulator, polarization control
Development of high-resolution photographic materials of the National Research Center "Kurchatov Institute" for nuclear research
Authors: Ryabova R. V.  , Balysh A. Ya.  , Ponomarev A. N.  , Senchenkov E. P.
Published: March 2023

In the course of the program for the development of high-resolution photographic materials for research in neutrino physics, the possibility of obtaining a nuclear emulsion with a resolution that exceeds the known materials by 5 times has been shown. The sensitivity in such materials is maintained at a high level, sufficient for the registration of nuclear radiation. With an increase in the concentration of silver halide up to 80 wt.%, nuclear photographic materials can be used to solve many physical problems Keywords: high-resolution photographic materials, nuclear research, silver halide concentration.
Ultra-wideband antenna for recording radio emission in the initial phase of a high-voltage laboratory atmospheric discharge
Authors: Baidin I. S.  , Oginov A. V.  , Parkevich E. V.
Published: March 2023

A compact ultra - wideband antenna, designed for the employment in the experiments on studying radio emission generated in the initial phase of the spark discharge, is presented. A flat type of antennas based on an expanding slit (Vivaldi antenna) is considered. The simulation and calculation of the antenna parameters are carried out. The results of using the antenna in laboratory experiments are demonstrated. It is shown that the generation of the highest frequency part of the radio emission spectrum coincides with the pre-breakdown stage of the discharge, before a sharp increase in the current starts. Keywords: Vivaldi antenna, microstrip antenna, radio emission, antenna simulation and calculation, atmospheric spark.
Oxygen diffusion in different thicknesses La-=SUB=-0.8-=/SUB=-Sr-=SUB=-0.2-=/SUB=-MnO-=SUB=-3-delta-=/SUB=- films on NdGaO-=SUB=-3-=/SUB=- substrates
Authors: Nikolaenko Yu. M.  , Efros N. B.  , Artemov A. N.
Published: March 2023

The results of investigation by the indirect method of step-by-step varying the oxygen content in the series of epitaxial La0.8Sr0.2MnO3-delta films on single-crystal NdGaO3 substrates are presented. Using numerical simulation we have revealed that the oxygen diffusion coefficient significantly decreases along the film thickness in the direction from the outer surface to the film-substrate interface under conditions of "compressive" mechanical stresses caused by the mismatch of the in-plane crystalline parameters of the film and substrate materials. In films of d~12-75 nm thickness, the effect is manifested in the fact that the value of the diffusion coefficient in the vicinity of the outer surface of the films also decreases significantly as the thickness of the films decreases. The questions of the applicability of the indirect method for evaluating the oxygen content in thin epitaxial films, as well as other manifestations of effects caused by mechanical stresses are discussed. Keywords: doped manganites, oxygen index, heat treatment, mechanical stress, the oxygen diffusion coefficient.
Residual stress in the carrier tape AISI 310S at the stage of deposition of the YSZ buffer layer when manufacturing of HTS-2G wire
Authors: Irodova A.V.  , Karpov I.D.  , Kruglov V.S.  , Krylov V.E.  , Shavkin S.V.  , Em V.T.
Published: March 2023

Using neutron diffraction we determined internal residual stress in the stainless steel AISI 310S carrier tape with a thickness of 100 μm and a width of 4 mm after mechanical polishing and the ABAD deposition of the textured YSZ buffer layer. It is shown that mechanical polishing causes a slight distension of the tape in the rolling plane. After the deposition of the YSZ layer, uniform tensile stress of 70 MPa isotropic in the rolling plane was observed inside the tape. Calculations have shown that it results from relaxation of compressive stress acting on the surface of the tape in a layer several times thicker than the YSZ layer. It is assumed that the surface of the tape is plastically deformed during the YSZ deposition. Keywords: residual stress, YSZ buffer layer, HTS-2G wire, AISI 310S carrier tape, neutron stress diffractometry.
Simulation of ion irradiation of crystalline and amorphous targets tokamak-reactor first wall materials
Authors: Meluzova D. S.  , Babenko P. Yu.  , Zinoviev A. N.  , Shergin A. P.
Published: March 2023

An overview of results concerning simulation of various processes which occur due to atomic bombardment of crystalline and amorphous solids is presented. With the use of original computational codes, the following data were obtained: reflection coefficients, projected energy losses and ranges of ions in solids, channeling data as well as sputtering yield and its dependence on incident angle of bombarding particles for Be-W and Ne-W combinations. Be, C and W targets were studied as these are among the plasma-facing materials in tokamaks, including ITER. The emphasis was made on atom-target combinations which lack reliable experimental data. Experimental data on other materials were used to verify calculations. A significant influence of the interaction potential used on the simulation results is shown. The reviewed results are tied by a common subject a study of interaction of plasma ions and first-wall materials of a tokamak-reactor and also by a common method of study the use of an original computational code. Keywords: scattering, ion sputtering, interaction potential, energy release.
Optimization of the thickness of the transition layer for the generation of ultrashort electron bunches by a laser pulse acting on a semi-bounded plasma
Authors: Kuznetsov S.V.
Published: March 2023

An analytical estimate is obtained for the range of thicknesses of the near-boundary plasma layer, which ensures the generation of ultrashort electron bunches under the action of a laser pulse on a semi-bounded rarefied plasma. Keywords: laser pulse, electron bunch, generation, injection.
The effect of maintaining a high conductivity state in high-voltage GaAs diodes switched-on in the delayed avalanche breakdown mode
Authors: Rozhkov A.V.  , Ivanov M.S.  , Rodin P.B.
Published: March 2023

It is experimentally established that high-voltage GaAs diodes maintain conducting state with low residual voltage after switching to the conducting state in the delayed impact-ionization mode. The duration of the constant current in the reversely-biased structure is determined by the duration of the applied rectangular voltage pulse (up to 100 ns) and significantly exceeds drift extraction and recombination times. The discovered effect of self-supporting conducting state resembles the "lock-on" effect in optically activated GaAs semiconductor switches and S-diodes with deep centers. The effect can be explained by shock ionization in narrow collapsing Gann domains. Keywords: high-voltage GaAs diodes, "lock-on" effect.
Field emission in nanotubes with the length of several nanometers
Authors: Sadykov N. R.  , Khrabrov R. S.  , Pilipenko I. A.
Published: March 2023

We consider the problem of field emission based on carbon nanotubes (CNT), which length differs from several nanometers up to dozens of nanometers. The particle transmission function is obtained, considering the difference of potentials on the ends of CNT to be U=2-3.5 V. The value of the emission current is calculated according to the obtained transmission function. We establish the dependence of the Nordheim function on the length of nanoparticles. We consider the limiting transition for the transmission coefficient for field emission from the cathode surface in the absence of nanoparticles on it. Linear dependence of the electrical current envelopes I on the field strength W is obtained. Keywords: field emission, nanotubes, Nordheim functions.
Effect of Sodium Atom Adsorption on the Electronic Structure of a Gold Film
Authors: Dementev P.A.  , Dementevа E.V.  , Lapushkin M.N.  , Smirnov D.A.  , Timoshnev S.N.
Published: March 2023

The electronic structure of a gold film deposited on W was studied during the adsorption of sodium atoms. An analysis of the photoemission spectra from the valence band and core levels of Au 4f and Na 2p upon synchrotron excitation in the photon energy range of 80-600 eV showed that Na adsorption leads to the formation of NaxAuy intermetallic compounds of various stoichiometry under the Na monolayer. Keywords: adsorption, sodium, gold, intermetallic compound.
Failure regions resembling geometrical shapes in sliding naation of Si-C-N thin films used for N/MEMS
Authors: Dash R.  , Bhattacharyya A. S.
Published: March 2023

The failure regions during sliding nano indentation of technologically important SiCN thin films resembled geometrical shapes of Lemniscate and cardiod. An adhesive strength of 9 GPa was estimated. The failure followed two different stress regimes, one tangential responsible for the wear and the other axial responsible for the film/substrate adhesion. EDS spectra of the scratched region shown complete adhesive failure. Keywords: sliding naation, SiCN thin films, adhesive strength
Occurrence of microstructures on steel surface under the influence of plasma focus discharge
Authors: Kirko D.L.  , Sidorov P.P.  , Bashutin O.A.  , Savjolov A.S.
Published: March 2023

The surface of metals after irradiation by intense streams of argon plasma arising in the plasma focus was studied. Metal samples of steel, copper, tungsten and molybdenum were investigated. Different types of microstructures were recorded. The surfaces of steel samples contain micropores with sizes of 0.1-3 μm with a shape close to circular. On copper and tungsten plates the appearance of fine-dispersed structures with sizes of 0.5-20 μm is observed. The possible mechanisms of the appearance of these microstructures are discussed. Keywords: plasma focus, intense plasma flows, micropores, filamentous discharge structure.
Features of inviscid fluid microjets outflow into vacuum
Authors: Yaskin A. S.  , Zarvin A. E.  , Kalyada V. V.  , Dubrovin K. A.
Published: March 2023

The paper presents experimental results on ethanol microjets outflow from a capillary (vertical flow by gravity) and from a hole in the wall (horizontal flow). The long-term liquid microjet flowing into vacuum has been shown to be highly unstable with sudden changes in direction, structure and observable density and essentially differing from well-studied modes of outflow into the atmosphere as well as from the modes of short-term outflow into vacuum. The main specific features of the flows and conditions giving rise to instabilities are described. Possible explanation of the reasons for microjet destruction is given. Keywords: liquid microjet, barocapillary instability of flows, modeling of vacuum conditions, ethanol.
Controllable neuromorphic dynamics of the phase locked loop
Authors: Tsyrulnikova L.A.  , Safin A.R.
Published: March 2023

We consider the neuromorphic dynamics of a filter-free phase locked loop with a phase modulation of a reference oscillator. The transition from pulsed single-spike dynamics to the bursting dynamics can be easily controlled by changing the depth and frequency of phase modulation, as well as the gain factor along the ring of the phase locked loop. The possibility of implementing neuromorphic calculations of the "OR" type in the scheme of three phase locked loops mutually coupled through a common loop filter (control circuit) is shown. The presented results can be used in designing hardware-implementable neuromorphic networks with increased frequency stability, resistant to noise effects. Keywords: neuromorphic dynamics, phase locked loop, logical operations.
Quantum noise source based on shot noise of a balanced photodetector with a tunable integrated optical beam splitter
Authors: Lebedev V.V.  , Petrov V.M.  , Ilichev I.V.  , Agruzov P.M.  , Shamrai A.V.
Published: March 2023

A broadband quantum noise source based on detection of shot noise of a balanced photodetector is demonstrated. Precise electro-optical tuning of the balanced photodetector circuit was carried out by an integrated optical beam splitter constructed in the form of the dual output Mach-Zehnder interferometer on a lithium niobate substrate. The classical component of the detected noise related to the relative intensity noise of a laser diode was suppressed by more than 15 dB. At the maximum laser power of 100 mW, the power spectral density of detected shot noise was 12 dB higher than the level of technical noise of the measuring system in the frequency band above 3 GHz. Keywords: quantum random number generator, vacuum fluctuations, shot noise measurements, integrated optics, lithium niobate
Investigation of the relative reactivity of aromatic compounds in air under the action of pulsed discharge plasma
Authors: Filatov I.E  , Uvarin V.V.  , Kuznetsov D.L.
Published: March 2023

Based on the method of competing reactions, a method for determining the relative reactivity of aromatic vapors in relation to the plasma components of a pulsed corona discharge is developed. The parameters of the relative reactivity of aromatic compounds in the air and nitrogen stream were obtained using model mixtures based on benzene, toluene, and xylene with a content of 250-500 ppm. The effect of water vapor on the process is shown. The obtained data will be useful for optimizing the processes of plasma-chemical air purification from the vapors of toxic aromatic compounds. Keywords: Corona discharge, aromatic compounds, non-equilibrium atmospheric pressure plasma, air purification, volatile organic compounds, BTEX.
Atomic luminescence of Ag during single-bubble sonolysis of silver nanoparticles aqueous suspension
Authors: Gareev B. M.  , Sharipov G. L.
Published: March 2023

For the first time, luminescence of Ag atoms was recorded during moving single-bubble sonolysis of silver nanoparticles aqueous colloidal suspension. This glow is caused by the entry of nanoparticles into a bubble deformable during motion and their decomposition to atoms with collisional excitation in the nonequilibrium plasma of the bubble. Nanoparticles were obtained by multibubble sonolysis of an AgNO3 solution with the addition of honey. This method was used to synthesize a stable suspension of Ag nanoparticles with an average size of ~ 10 nm. By comparing the experimental spectrum of this suspension and simulated spectra of Ag, the electron temperature in the bubble plasma was found to be ~ 10 000 K. Keywords: single-bubble sonoluminescence, silver nanoparticles, electron plasma temperature.
The Noise Generation in One-Frequency IMPATT Diode Oscillator of Millimeter Wave Range on the Effect of Low-Frequency Harmonic Oscillation
Authors: Myasin E. A.
Published: March 2023

The investigation of effect of the low-frequency harmonic oscillation on the nourishment circuit of the 7 mm wave region IMPATT diode oscillator was continued. In first time it was shown, that excitement of noise and the maximum height-frequency noise spectrum extension at a low-frequency oscillation amplitude increasing are connected with a transitory decreasing of the diode current lower the start current of height-frequency generation in the IMPATT diode oscillator. Keywords: effect, low-frequency harmonic oscillation, IMPATT diode oscillator, 7mm wave range, spectrum, amplitude detector.
Features of the radiative properties of quantum-size particles of narrow-gap semiconductors
Authors: Zhukov N. D.  , Sergeev S. A.  , Hazanov A. A.  , Yagudin I. T.
Published: March 2023

For colloidal quantum-size particles (QP) of narrow-gap semiconductors, in contrast to quantum dots of wide-gap CdSe, in QP-PbS there take place an anomalous temperature dependence of the photoluminescence intensity. Also, in the planar microstructure containing QP-InSb, long-wavelength radiation (more than 3 μm) and photoconductivity (over 20 μm) was observed. Under certain conditions, the radiation intensity and photoconductivity demonstrate a resonance maximum. The effects were explained in the model of a one-dimensional quantum oscillator, which energy substantially depends on the effective mass of its quasi-free electron. This leads to competition between the manifestations of long-wave radiation and photoluminescence, and hence, to the anomalous temperature dependence of photoluminescence. It is assumed that QP-InSb in a planar microstructure can be sources and receivers of terahertz radiation, which properties depend on the crystal structure of quantum-sized particles determined by the parameters of their synthesis. Keywords: quantum-dimensional particle, quantum dot, narrow-gap semiconductor, effective mass, Brillouin zone, dimensional quantization, quantum oscillator, photoluminescence, long-wavelength radiation.
Virtual Partnership Addressing Mental Health Crises: Mixed Methods Study of a Coresponder Program in Rural Law Enforcement
Authors: Nataliansyah M Muska , Merchant Kimberly A S , Vakkalanka J Priyanka , Mack Luke , Parsons Seth , Ward Marcia M
Published: March 2023

Background

A mental health crisis can create challenges for individuals, families, and communities. This multifaceted issue often involves different professionals from law enforcement and health care systems, which may lead to siloed and suboptimal care. The virtual crisis care (VCC) program was developed to provide rural law enforcement with access to behavioral health professionals and facilitated collaborative care via telehealth technology.

Objective

This study was designed to evaluate the implementation and use of a VCC program from a telehealth hub for law enforcement in rural areas.

Methods

This study used a mixed methods approach. The quantitative data came from the telehealth hub’s electronic record system. The qualitative data came from in-depth interviews with law enforcement in the 18 counties that adopted the VCC program.

Results

Across the 181 VCC encounters, the telehealth hub's recommended disposition and the actual disposition were similar for remaining in place (n=141, 77.9%, and n=137, 75.7%, respectively), voluntary admission (n=9, 5.0%, and n=10, 5.5%, respectively), and involuntary committal (IVC; n=27, 14.9%, and n=19, 10.5%, respectively). Qualitative insights related to the VCC program's implementation, use, benefits, and challenges were identified, providing a comprehensive view of the virtual partnership between rural law enforcement and behavioral health professionals.

Conclusions

Use of a VCC program likely averts unnecessary IVCs. Law enforcement interviews affirmed the positive impact of VCC due to its ease of use and the benefits it provides to the individuals in need, the first responders involved, law enforcement resources, and the community.
The Effectiveness of an eHealth Family-Based Intervention Program in Patients With Uncontrolled Type 2 Diabetes Mellitus (T2DM) in the Community Via WeChat: Randomized Controlled Trial (Preprint)
Authors: Feng Yuheng , Zhao Yuxi , Mao Linqi , Gu Minmin , Yuan Hong , Lu Jun , Zhang Qi , Zhao Qian , Li Xiaohong
Published: March 2023

BACKGROUND

Intervention based on family support and risk perception can enhance type 2 diabetes mellitus (T2DM) patients’ self-care activities. In addition, eHealth education is considered to improve family members’ support for patients with T2DM. However, there is little evidence from rigorously designed studies on the effectiveness of an intervention combining these approaches.

OBJECTIVE

This randomized controlled trial (RCT) aimed to assess the effectiveness of an eHealth family-based health education intervention for patients with T2DM to improve their glucose control, risk perception, and self-care behaviors.

METHODS

This single-center, 2-parallel-group RCT was conducted between 2019 and 2020. Overall, 228 patients were recruited from Jiading District, Shanghai, and randomly divided into intervention and control groups. The intervention group received an eHealth family intervention based on community management via WeChat, whereas the control group received usual care. The primary outcome was the glycated hemoglobin (HbA1c) level of the patients with T2DM, and the secondary outcomes were self-management behavior (general and specific diet, exercise, blood sugar testing, foot care, and smoking), risk perception (risk knowledge, personal control, worry, optimism bias, and personal risk), and family support (supportive and nonsupportive behaviors). A 2-tailed paired-sample t test was used to compare the participants at baseline and follow-up within the control and intervention groups. An analysis of covariance was used to measure the intervention effect.

RESULTS

In total, 225 patients with T2DM were followed up for 1 year. After intervention, they had significantly lower HbA1c values (β=–.69, 95% CI –0.99 to –0.39; P<.001). They also had improved general diet (β=.60, 95% CI 0.20 to 1.00; P=.003), special diet (β=.71, 95% CI 0.34 to 1.09; P<.001), blood sugar testing (β=.50, 95% CI 0.02 to 0.98; P=.04), foot care (β=1.82, 95% CI 1.23 to 2.42; P<.001), risk knowledge (β=.89, 95% CI 0.55 to 1.24; P<.001), personal control (β=.22, 95% CI 0.12 to 0.32; P<.001), worry (β=.24, 95% CI 0.10 to 0.39; P=.001), optimism bias (β=.26, 95% CI 0.09 to 0.43; P=.003), and supportive behaviors (β=5.52, 95% CI 4.03 to 7.01; P<.001).

CONCLUSIONS

The eHealth family-based intervention improved glucose control and self-care activities among patients with T2DM by aiding the implementation of interventions to improve T2DM risk perceptions among family members. The intervention is generalizable for patients with T2DM using health management systems in community health centers.

CLINICALTRIAL

Chinese Clinical Trial Registry ChiCTR1900020736; https://www.chictr.org.cn/showprojen.aspx?proj=31214
Using Wearable Technology to Quantify Physical Activity Recovery: Secondary Report From the AFTER (App-Facilitated Tele-Rehabilitation) Program for COVID-19 Survivors Randomized Study (Preprint)
Authors: Churchill Laura , Morrow Mary , Capin Jacob J , Jolley Sarah E , Hare Kristine , MaWhinney Samantha , Stevens-Lapsley Jennifer E , Erlandson Kristine M
Published: March 2023

BACKGROUND

Knowledge on physical activity recovery after COVID-19 survival is limited. The AFTER (App-Facilitated Tele-Rehabilitation) program for COVID-19 survivors randomized participants, following hospital discharge, to either education and unstructured physical activity or a telerehabilitation program. Step count data were collected as a secondary outcome, and we found no significant differences in total step count trajectories between groups at 6 weeks. Further step count data were not analyzed.

OBJECTIVE

The purpose of this analysis was to examine step count trajectories and correlates among all participants (combined into a single group) across the 12-week study period.

METHODS

Linear mixed models with random effects were used to model daily steps over the number of study days. Models with 0, 1, and 2 inflection points were considered, and the final model was selected based on the highest log-likelihood value.

RESULTS

Participants included 44 adults (41 with available Fitbit [Fitbit LLC] data). Initially, step counts increased by an average of 930 (95% CI 547-1312; P<.001) steps per week, culminating in an average daily step count of 7658 (95% CI 6257-9059; P<.001) at the end of week 3. During the remaining 9 weeks of the study, weekly step counts increased by an average of 67 (95% CI −30 to 163; P<.001) steps per week, resulting in a final estimate of 8258 (95% CI 6933-9584; P<.001) steps.

CONCLUSIONS

Participants showed a marked improvement in daily step counts during the first 3 weeks of the study, followed by more gradual improvement in the remaining 9 weeks. Physical activity data and step count recovery trajectories may be considered surrogates for physiological recovery, although further research is needed to examine this relationship.

CLINICALTRIAL

ClinicalTrials.gov NCT04663945; https://tinyurl.com/2p969ced
Economic Evaluation of Telerehabilitation: Systematic Literature Review of Cost-Utility Studies (Preprint)
Authors: Baffert Sandrine , Hadouiri Nawale , Fabron Cécile , Burgy Floriane , Cassany Aurelia , Kemoun Gilles
Published: March 2023

BACKGROUND

Telerehabilitation could benefit a large population by increasing adherence to rehabilitation protocols.

OBJECTIVE

Our objective was to review and discuss the use of cost-utility approaches in economic evaluations of telerehabilitation interventions.

METHODS

A review of the literature on PubMed, Scopus, Centres for Review and Dissemination databases (including the HTA database, the Database of Abstracts of Reviews of Effects, and the NHS Economic Evaluation Database), Cochrane Library, and ClinicalTrials.gov (last search on February 8, 2021) was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were defined in accordance with the PICOS (population, intervention, comparison, outcomes, and study design) system: the included studies had to evaluate patients in rehabilitation therapy for all diseases and disorders (population) through exercise-based telerehabilitation (intervention) and had to have a control group that received face-to-face rehabilitation (comparison), and these studies had to evaluate effectiveness through gain in quality of life (outcome) and used the design of randomized and controlled clinical studies (study).

RESULTS

We included 11 economic evaluations, of which 6 concerned cardiovascular diseases. Several types of interventions were assessed as telerehabilitation, consisting in monitoring of rehabilitation at home (monitored by physicians) or a rehabilitation program with exercise and an educational intervention at home alone. All studies were based on randomized clinical trials and used a validated health-related quality of life instrument to describe patients’ health states. Four evaluations used the EQ-5D, 1 used the EQ-5D-5L, 2 used the EQ-5D-3L, 3 used the Short-Form Six-Dimension questionnaire, and 1 used the 36-item Short Form survey. The mean quality-adjusted life years gained using telerehabilitation services varied from –0.09 to 0.89. These results were reported in terms of the probability that the intervention was cost-effective at different thresholds for willingness-to-pay values. Most studies showed results about telerehabilitation as dominant (ie, more effective and less costly) together with superiority or noninferiority in outcomes.

CONCLUSIONS

There is evidence to support telerehabilitation as a cost-effective intervention for a large population among different disease areas. There is a need for conducting cost-effectiveness studies in countries because the available evidence has limited generalizability in such countries.

CLINICALTRIAL

PROSPERO CRD42021248785; https://tinyurl.com/4xurdvwf
Outbreak detection of coronavirus disease epidemic: Transmission dynamics using machine learning techniques (Preprint)
Authors: Lee Hyojung , Cho Giphil , Park Jeong Rye , Choi Yongin , Ahn Hyeonjeong
Published: March 2023

BACKGROUND

In the face of the rapid spread of the coronavirus disease (COVID-19) pandemic, predicting the spread of COVID-19 can help healthcare providers prepare and respond to outbreaks more quickly and effectively, ultimately leading to better care for patients.

OBJECTIVE

We aimed to develop a method to detect early COVID-19 outbreaks or identify potential early outbreaks using machine learning (ML) by analyzing epidemiological data in the Republic of Korea.

METHODS

ML methods were developed to predict the transmission trend of COVID-19, and a new method was proposed for detecting the start time of new outbreaks. We constructed risk index and label to measure the change in the transmission trend of COVID-19. Additionally, the study used ML methods to detect the start time of new outbreaks based on Label 2, which was maintained for at least 14 days, and predicted labels to detect future transmission trends early.

RESULTS

ML methods had a high accuracy of more than 90% in estimating the classification of the transmission trend (Increase, Maintain, or Decrease). The proposed method not only accurately predicted the start time of new major outbreaks but also provided a standard for accurately predicting the start time of minor outbreaks. Random Forest exhibited the most accurate estimation of outbreak detection.

CONCLUSIONS

The proposed method can provide an explainable standard for accurately predicting the start time of both major and minor outbreaks. This can help develop effective prevention and control measures for COVID-19 transmission.
The level of vitamin D in the first trimester of pregnancy and its effect on the anthropometric parameters of а newborn
Authors: Budnik T.O. , Boychuk A.V.
Published: March 2023

Background. The prevalence of vitamin D deficiency appears to be increasing worldwide. Pregnant women are at risk of developing vitamin D deficiency. Vitamin D status has a great impact on both pregnancy and the fetus. Vitamin D deficiency during pregnancy has been associated with several adverse pregnancy outcomes. The purpose of the study was to evaluate serum vitamin D level during the first trimester of pregnancy and its effect on the neonatal anthropometric measures. Material and methods. A prospective study among 71 pregnant women aged 19 to 42 years in the first trimester was carried out between October 2018 to April 2020. A survey of pregnant women (socio-demographic characteristics, anamnestic data and diet) was conducted, and the maternal serum total vitamin D level was determined by enzyme immunoassay. Neonatal anthropometric parameters (weight, body length, weight/length ratio) were measured. Results. Vitamin D deficiency was observed in 41 (57.7%) of pregnant women, insufficiency in 7 (9.9%), and the optimal level in 23 (32.4%) of examined women. Women with vitamin D deficiency were more likely to have a history of miscarriage than those with optimal D status (odds ratio 9.06, 95% confidence interval 1.11–73.86, Р=0.0396). We have not found the influence of other factors (age, social status, body mass index, number of pregnancies) on the maternal vitamin D level. There were no significant differences between indicators of weight by age, body length of a child by age, and Apgar scores depending on the vitaminD levels of pregnant women. Conclusions. The study showed that the optimal vitamin D level is observed only in 32.4% of cases, and its deficiency or insufficiency occurs in 67.6% of pregnant women in the first trimester. The study did not reveal the correlation between maternal vitamin D level during the first trimester of pregnancy and neonatal anthropometric measures. Given the trend towards lower weight/length ratio to gestational age of the newborns from mothers with vitamin D deficiency, further studies are needed.
Proprotein convertase subtilisin/kexin type 9 inhibitors: prospects for cholesterol-lowering therapy in type 2 diabetes
Authors: Serhiyenko V.A. , Serhiyenko A.A.
Published: March 2023

Diabetic dyslipoproteinemia (DLP), characterized by quantitative, qualitative, and kinetic changes in all major circulating lipids, contributes to an increased risk of atherosclerotic cardiovascular disease in patients with type 2 diabetes mellitus (DM). Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) by human monoclonal antibodies is a promising treatment for diabetic DLP. Several drugs differ in their mechanisms of inhibition of PCSK9 activity. The following groups are conditionally distinguished: PCSK9 monoclonal antibodies (anti-PCSK9 monoclonal antibodies): evolocumab, alirocumab, bococizumab (injectable); other injectable medications with different mechanism of actions (inclisiran, SPC4061, SPC5001, adnectin BMS-962476, LIB003, anti-PCSK9 vaccine; anti-PCSK9 vaccine (nanoparticle-based); orally administered drugs (PF-06446846, DS-9001a, SRT3025); cholesteryl ester transfer protein/PCSK9 inhibitors (anacetrapib, evacetrapib, torcetrapib, K-312). This review aims to discuss the role of alirocumab and evolocumab, fully humanized monoclonal antibodies, in the treatment of type 2 DM patients with DLP and to consider their effectiveness and safety. Strategy of search. Scopus, Science Direct (from Elsevier), and PubMed, including the Medline databases, were searched. The following keywords were used: autonomic nervous system, heart rate variability, baroreflex sensitivity, diabetic cardiac autonomic neuropathy, and MeSH terms. A manual search of the bibliography of publications was used to identify research results that could not be found with the online search. Statins are the first line of choice for treating DLP in patients with type 2 DM to reduce the risk of atherosclerotic cardiovascular disease. Ezetimibe is the next drug to be added if patients’ low-density lipoprotein cholesterol levels are higher than acceptable. In cases of failure of the combination of statins with ezetimibe, PCSK9 inhibitor is a reasonable and rational choice. Overall, clinical data suggest that PCSK9 inhibitors are well tolerated and provide a significant reduction in low-density lipoprotein cholesterol levels in type 2 DM patients with DLP in addition to high-intensity statin therapy. The use of PCSK9 inhibitors is not associated with impaired glycemic control or increased risk of diabetes development in individuals without previously diagnosed DM and may prevent or reduce subsequent cardiovascular events.
Basal insulin titration algorithms in patients with type 2 diabetes: the simplest is the best (?)
Authors: Katerenchuk V.I.
Published: March 2023

Basal insulin is the first and main component of insulin therapy in patients with type 2 diabetes mellitus (T2DM). Based on the shortcomings of human NPH insulin and the advantages provided by long-acting basal insulin analogues, they are recommended for priority use in patients with T2DM. The leading factor in the success of insulin therapy is titration of its dose with the achievement of the target range of glycemia. Data from clinical trials and real clinical practice indicate that simpler dose titration algorithms ensure better achievement of glycemic goals with a lower risk of hypoglycemia. In addition, simple dose titration algorithms are better accepted by patients and increase satisfaction with treatment. The leading societies of diabetologists ADA/EASD and AACE/ACE recommend the use of simple dose titration algorithms. Recent clinical trials on the effectiveness of the insulin glargine dose titration based on the INSIGHT algorithm, which, unlike the traditional options for changing the dose 1–2 times a week, involves a daily correction of the insulin glargine dose by 1 Unit, have proven its effectiveness and safety. Most patients prefer this type of insulin dose titration. The same titration algorithm can be used for a fixed combination of glargine with lixisenatide, which was also confirmed by the results of clinical trials. In general, simplified options for correcting the basal insulin dose have demonstrated their effectiveness and allow increasing the percentage of patients who manage to achieve the glycemic goal without increasing the risk of hypoglycemia. When prescribing basal insulin, physician must determine the target range of glycemia, demonstrate the titration algorithm that is acceptable for each insulin and which a patient will use to achieve the glycemic goal.
The Application of Real Option in Corporate Investment
Authors: Hu Xiaonan
Published: March 2023

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