Microwave Radiation Field Research Articles

Modified zinc oxide nanoparticles as potential drug carrier

The objective of this research was to investigate the feasibility of creating a stable drug carrier using zinc oxide. This carrier, with its surface modified by a galactose coating, aimed to demonstrate reduced toxicity compared to the uncoated zinc oxide nanoparticles. A series of zinc oxide nanoparticles were synthesized, each modified with galactose. The processes were carried out in a microwave radiation field. The synthesized products underwent analysis, including XRD, ATR-FTIR and TEM-EDS analysis. Also, DLS technique was applied to determined size and electrokinetic potential of nanoparticles in different media. Further investigation assessed the impact of the synthesized zinc oxide nanoparticles on CHO cell cytotoxicity and their proliferation. XRD technique confirmed the obtaining of zinc oxide nanoparticles. Modification with galactose didn't impact their purity. ATR-FTIR analysis confirmed Zn-O bonds. Galactose presence was confirmed at its highest molar ratio. TEM-EDS analysis revealed pure zinc oxide nanoparticles' spiked structure and modified nanoparticles' less organized arrangement, both showing bar-like shape. DLS technique determined nanoparticle sizes between 217 and 764 nm. Nanoparticle suspensions were found stable in various environments. In vitro cell viability analysis indicated reduced cytotoxicity and enhanced cell development with modified zinc oxide nanoparticles compared to reference unmodified particles. Regarding the outcomes, it can be deduced that the suggested process parameter values consistently yield stable galactose-modified zinc oxide nanoparticles. These modified nanoparticles exhibit lower cytotoxicity towards CHO cells compared to pure zinc oxide. Furthermore, they actively promote the proliferation of normal cells, aligning with the desired outcome.

Microwave spectroscopy of positronium atoms in free space

We report measurements of the positronium (Ps) $2^{3}S_{1}\ensuremath{\rightarrow}2^{3}P_{2}$ interval in which atoms traveling in free space were irradiated with microwave radiation generated using a horn antenna. Previous measurements of this transition, performed using atoms in waveguides, exhibited asymmetric and shifted line shapes. In the free-space measurements we report here, much smaller line-shape asymmetry was observed, but with large frequency shifts that varied with the orientation of the horn antenna. Our observations are supported by line-shape simulations and demonstrate that variations in the microwave radiation field distribution can perturb measured line shapes and give rise to apparent frequency shifts without necessarily causing large asymmetries; this effect can explain previous measurements in which an apparent discrepancy with predictions from quantum electrodynamics was ob- served [L. Gurung, T. J. Babij, S. D. Hogan, and D. B. Cassidy, Phys. Rev. Lett. 125, 073002 (2020)].

Linewidth, field, and frequency in electron paramagnetic resonance (EPR) spectroscopy.

EPR spectroscopy requires a combination of fixed microwave radiation and resonant external magnetic field. Bigger is not necessarily better in that low-frequency and -field EPR (LFEPR) can provide useful information as well as reduced linewidths that can allow better observation of hyperfine coupling. More importantly, LFEPR allows very low g values to be readily observed, such as often found in low-spin d5 systems.

Microwave Field Metrology Based on Rydberg States of Alkali-Metal Atoms

The high-precision determination of microwave radiation parameters may be based on measurements of the spectral characteristics of radiation transitions between the Rydberg states of atoms. Frequencies and matrix elements are calculated for dipole transitions from even-parity nS1/2 and nD5/2 to odd-parity n′P3/2 and n′F7/2 (where n′ = n, n ± 1, n ± 2) for the Rydberg states of alkali-metal atoms. The matrix elements determine the splitting of Rydberg-state energy levels in the field of a resonance microwave (μw) radiation, which results in the splitting of the resonance in electromagnetic induced transparency (EIT). Numerical computations based on the single-electron quantum defect method (QDM) and the Fues’ model potential (FMP) approach with the use of the most reliable data of the current literature on quantum defect values were performed for the 2S, 2P, 2D and 2F series of the Rydberg states of Li, Na, K, Rb and Cs atoms. The calculated data were approximated by quadratic polynomials of the principal quantum number. The polynomial coefficients were determined with the use of a standard curve-fitting interpolation polynomial procedure for numerically presented functions. The approximation equations may be used for the accurate evaluation of the frequencies and matrix elements of μw transitions in wide ranges of the Rydberg-state quantum numbers n >> 1.

Positronium microwave spectroscopy using Ramsey interferometry

We describe an experimental arrangement suitable for performing microwave spectroscopy measurements of the positronium (Ps) n=2 fine structure using Ramsey interferometry. Simulations are presented concerning the production of energetic 2,^3S_1 Ps atoms from a Xe gas cell, and their subsequent interactions with a pair of waveguides in which coherent microwave radiation fields are applied. We conclude that for realistic experimental parameters, optimized using a Monte Carlo simulation, a gas cell length of 10 cm with a gas pressure of 0.5 Pa and a positron beam energy of 40 eV, count rates on the order of 50 Hz should be possible.Graphical abstract

Использование СВЧ излучения для предынкубационной стимуляции яиц сельскохозяйственной птицы

The article describes the effect of short-term exposure to an electromagnetic field (EMF) of microwave radiation at a frequency of 2.45 GHz on the rate of development of an embryo in an egg of an agricultural bird. To carry out the experiments, a laboratory microwave setup was developed for controlled and controlled impact on the object being processed. The dielectric characteristics of protein and yolk of fertilized and non-fertilized poultry eggs were measured and analyzed, on the basis of which computer electromagnetic modeling of a microwave chamber for a laboratory pre-incubation processing unit was carried out. The influence of the microwave field on the concentration of proteins in the eggs of poultry was experimentally tested depending on the time of exposure. Keywords: EMF MICROWAVE RADIATION, ENVIRONMENTALLY FRIENDLY STIMULATION OF DEVELOPMENT

Использование СВЧ излучения для предынкубационной стимуляции яиц сельскохозяйственной птицы

The article describes the effect of short-term exposure to an electromagnetic field (EMF) of microwave radiation at a frequency of 2.45 GHz on the rate of development of an embryo in an egg of an agricultural bird. To carry out the experiments, a laboratory microwave setup was developed for controlled and controlled impact on the object being processed. The dielectric characteristics of protein and yolk of fertilized and non-fertilized poultry eggs were measured and analyzed, on the basis of which computer electromagnetic modeling of a microwave chamber for a laboratory pre-incubation processing unit was carried out. The influence of the microwave field on the concentration of proteins in the eggs of poultry was experimentally tested depending on the time of exposure. Keywords: EMF MICROWAVE RADIATION, ENVIRONMENTALLY FRIENDLY STIMULATION OF DEVELOPMENT

Josephson Effect in MgB2/Pd/Nb Trilayer Josephson Junctions

This paper reports fabrication techniques and results of MgB2/Pd/Nb trilayer Josephson junctions. The MgB2 bottom electrode was co-evaporated by molecular beam epitaxy (MBE) technique from both magnesium and boron sources at a low substrate temperature ~ 300 °C, while the interlayer and the top niobium electrode (Pd/Nb bilayer) were deposited ex-situ using RF sputtering. The junctions exhibited and Josephson effect as well as a modulation of the critical current in a magnetic field applied in a direction normal to the junction plane. Fractional and integer Shapiro steps were observed at voltages corresponding to the frequency of the applied microwave radiation field. The products of the junctions compare well with the previously reported values. The results suggest that it should be possible to fabricate all-MgB2 and MgB2 as one of the electrodes Superconductor/Normal/Superconductor (SNS), Superconductor/Insulator/Superconductor (SIS) or even Superconductor/Ferromagnet/Superconductor (SFS) tunnel junctions with interesting characteristics and for various applications.
 Keywords: MgB2; all-MgB2; Josephson Tunnel junctions; trilayer devices; Niobium

Artificial radio lighting with sources of microwave dynamic chaos.

Application of dynamic chaos for the illumination of the surrounding space by artificial incoherent sources of microwave radiation with the purpose of its subsequent observation using special receiving equipment is considered. An incoherent broadband microwave radiation field is provided by "radio light lamps" based on dynamic chaos generators. The radio light is received with specially designed sensitive elements that combine the properties of an envelope detector in communication systems and a radiometer. It is shown that with the help of directional antennas connected to these sensitive elements, it is possible to create receivers with spatial resolution for visualizing a part of the surrounding space in artificial radio light. Radio light images of a room have been obtained. The possibility to detect changes associated with the emergence of new objects on these images is demonstrated.

Prospects for the use of microwave energy in grain crop seeding

This study looks at determining the main trends in the application of microwaves on plants in agricultural production in the processing of grain material, it provides examples of their effectiveness and an overview of the use of microwaves on plants available on the Russian market. Additionally, the research studied the experience and developments of leading scien-tists in the field of microwave radiation. Analysis of the available sources provided information on the positive effect of microwave radiation in the processing of crops. The use of microwaves on plants during drying destroys pathogens and bacteria, in particular, microwave processing of red lentils reduces grey mould damage by up to 30%. Positive results are also noted in the microwave processing of other crops, providing an increase in germination capacity of up to 7% and yield growth of up to 6%. The microwave plant market in Russia is represented mainly by dryers, and the use of microwaves on plants combining several functions of drying, disinfection, and pre-sowing stimulation.

Observation of asymmetric line shapes in precision microwave spectroscopy of the positronium 2S13→2PJ3 ( J=1,2 ) fine-structure intervals

We report new measurements of the positronium (Ps) $2^{3}S_{1}\ensuremath{\rightarrow}2^{3}P_{J}$ fine-structure intervals, ${\ensuremath{\nu}}_{J}$ ($J=0,1,2$). In the experiments, Ps atoms, optically excited to the radiatively metastable $2^{3}S_{1}$ level, flew through microwave radiation fields tuned to drive transitions to the short-lived $2^{3}P_{J}$ levels, which were detected via the time spectrum of subsequent ground-state Ps annihilation radiation. Both the ${\ensuremath{\nu}}_{1}$ and ${\ensuremath{\nu}}_{2}$ line shapes were found to be asymmetric, which, in the absence of a complete line-shape model, prevents accurate determination of these fine-structure intervals. Conversely, the ${\ensuremath{\nu}}_{0}$ line shape did not exhibit any significant asymmetry; the observed interval, however, was found to disagree with QED theory by 4.2 standard deviations.

Microwave power dissipation in a microwave plasma filament

A plasma channel (filament) formed in the electromagnetic field of microwave (MW) radiation shows promise for its application for off-body non-electrode modification of a gas flow (plasma aerodynamics) and in the plasma assisted combustion process. In these problems, the channel is considered as an object that converts the energy of electromagnetic radiation into gas heating. To estimate the total power absorbed in the plasma from above, simple formula is obtained. Numerical calculations in air in the pressure range P = 20-100 Torr based on a simplified 2D model using a fairly complete system of plasma-chemical reactions have shown that the total absorbed power is close to its estimate from above when the plasma channel develops.

Effects of high energy on steel structure in deformation

The author of the article investigates how microwave radiation affects the processes of active deformation and mechanical stress relaxation in stressed stainless steel specimen under the electric current and when vector E (of microwave radiation) moves in different directions along the axe of the specimen. When vector E of microwave radiation was oriented in a longitudinalis way and electric current was passed, the softening of metal increased from 22 to 30 %. Multi-criteria analysis of steel samples with electric current and samples with no electric current was made. Analysis findings showed that external energy deposition influenced greatly on deformation of steel crystals. The action of high-density electric current pulses and microwave radiation on a sample loaded above the yield strength increases the ductility of stainless steel, and its strength characteristics, the microstructure is modified. Phase composition of steel was also investigated. The studies showed that the content of martensitic and austenitic phases in steel changed significantly. Moreover, the results showed that there was an additional mechanism of electroplastic deformation in the crossed fields of microwave radiation and magnetic field of current.

Microwave (2ω1 − ω2) frequency mixing by mobile carriers in electron-doped and gapped graphene

We theoretically study the generation of microwave radiation at frequency 2ω1−ω2, produced by two microwaves, of frequencies ω1 and ω2, normally incident on monolayer graphene grown epitaxially on a SiC substrate and doped by electrostatic gating. Two mechanisms responsible for this third-order nonlinear effect are considered: (i) the graphene’s conduction band nonparabolicity arising from the substrate-induced bandgap opening at the Dirac points of the graphene’s Brillouin zone and (ii) the energy dependence of the electron-momentum relaxation time. Both mechanisms are incorporated in our Boltzmann-equation-based treatment of the graphene’s third-order nonlinear response to the applied microwave radiation field. Within the framework of the approach, we evaluate the output power P2ω1−ω2 of the (2ω1−ω2) microwave radiation as a function of the graphene’s carrier density nS controlled by the applied gate voltage. Our formulation predicts an unexpected nonmonotonous behavior of this function: there is a pronounced minimum in the P2ω1−ω2(nS), which is followed by a maximum. This finding may serve to provide a rational explanation for this type of oscillation as observed by Dragoman et al. [Appl. Phys. Lett. 97, 093101 (2010)] in the output power of the microwave harmonic generation in gated graphene, which are not properly construed so far.

Precision Microwave Spectroscopy of the Positronium n=2 Fine Structure.

We report a new measurement of the positronium (Ps) 2^{3}S_{1}→2^{3}P_{0} interval. Slow Ps atoms, optically excited to the radiatively metastable 2^{3}S_{1} level, flew through a microwave radiation field tuned to drive the transition to the short-lived 2^{3}P_{0} level, which was detected via the time spectrum of subsequent ground state Ps annihilation radiation. After accounting for Zeeman shifts we obtain a transition frequency ν_{0}=18501.02±0.61 MHz, which is not in agreement with the theoretical value of ν_{0}=18498.25±0.08 MHz.

Chemical puzzles in the search for new, flexible derivatives of lurasidone as antipsychotic drugs

In the pharmacotherapy of schizophrenia, there is a lack of effective drugs, and currently used agents cause a large number of side effects. The D2, 5-HT1A, 5-HT2A receptors are among the most important receptor targets in the treatment of schizophrenia, but antagonism at 5-HT6 and 5-HT7 receptors may bring about additional improvement of cognitive functions. However, doubt exists regarding the importance of 5-HT7R in the pharmacotherapy. In 2010, lurasidone (with high affinity for D2, D3, 5-HT1A, 5-HT2A, 5-HT7 receptors) was approved for the treatment of schizophrenia. Due to the efficacy of the mentioned drug and doubts related to the role of 5-HT7R, we decided to obtain compounds with an activity profile similar to that of lurasidone, but with the reduced affinity for 5-HT7R and increased affinity for 5-HT6R. For this purpose, we chose aflexible hexyl derivative of lurasidone (2-(6-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)hexyl)hexahydro-1H-4,7-methanoisoindole-1,3(2H)-dione 1a) as a hit structure. After molecular modeling, we modified it, in the area of the arylpiperazine and imide group, using the moieties found in other known CNS drugs. We received the compounds in accordance with the previously developed method of ecological synthesis in the microwave radiation field. Among the obtained compounds, N-(6-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)hexyl)naphthalene-sulfonamides 1v and 1w were distinguished as multifunctional ligands showing increased affinity for 5-HT6R, and 2-(6-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)hexyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one 1i – a multifunctional ligand showing moderate affinity for 5-HT6R and threefold lower for 5-HT7R. In the paper, we discuss some of the observed dependencies regarding 5-HT6/5-HT7R affinity using molecular docking methods.

The Josephson Effect in PbIn/Fe1 –ySe1 –xTex Point Contacts: Probing the Order Parameter Symmetry

Characteristics of the Josephson effect in Pb0.6In0.4/FeSe0.4Te0.6 point contacts with the current flowing parallel to ab plane of the iron chalcogenide crystal (with critical temperature Tc ≈ 15 K) have been studied. Dependences of the critical current Ic and amplitudes In of the first steps of current (Shapiro steps) in the current–voltage (I–V) characteristics (n = 0, 1, 2; I0 = Ic) on the microwave power P (at frequency f = 7.6 GHz) and dependences of the characteristic voltage Vc(T) = IcRN (RN being the normal state resistance) on the temperature T have been measured. It is found that the characteristics of contacts (Ic, RN, Vc) obtained for initial parts of the I–V curves do not adequately describe the oscillations of current steps in the microwave radiation field. A method is proposed for determining the normalized microwave frequency Ω = 2πf(2eVc/$$\hbar $$)–1 that provides quantitative description of the current oscillation steps in the framework of a resistive contact model and allows one to check that the Josephson superconducting current Is is proportional to sin(aφ) (a = 1, 2), where φ is the phase difference of the order parameters. Comparison of the measured In($$\sqrt P $$) curves to those calculated using the resistive model showed that Is = Icsinφ, in agreement with the conventional s and s++ symmetry of the order parameter in FeSe0.4Te0.6. It is established that Vc of the contacts studied is proportional to T in a wide temperature interval.

Sensing microwave photons with a Bose\u2013Einstein condensate

We consider the interaction of a magnetically trapped Bose–Einstein condensate of Rubidium atoms with the stationary microwave radiation field sustained by a coplanar waveguide resonator. This coupling allows for the measurement of the magnetic field of the resonator by means of counting the atoms that fall out of the condensate due to hyperfine transitions to non-trapped states. We determine the quantum efficiency of this detection scheme and show that weak microwave fields at the single-photon level can be sensed.

New dual ligands for the D2 and 5-HT1A receptors from the group of 1,8-naphthyl derivatives of LCAP.

More than 300 million people are suffering from depression, one of the civilization diseases in the 21st century. Serotonin 5-HT1AR and dopamine D2R play an important role in the treatment and pathogenesis of depression. Moreover, in recent years, the efficacy of dual 5-HT1A/D2 receptors ligands has been demonstrated in the fight against depression. In this work the new bulky arylpiperazine derivatives (LCAP) were synthesized in microwave radiation field. The affinities for the selected serotonin (5-HT1A,5-HT2A,5-HT6,5-HT7) and dopamine (D2) receptors have been evaluated in vitro. Compounds 5.3a, 5.4, 5.1c, 5.3d, 5.2a are promising dual 5-HT1AR/D2R ligands. The SAR analysis were additionally supported with molecular docking studies.

Changes in Puffing Pattern ofDrosophila melanogaster(Diptera: Drosophilidae) Polytene Chromosomes after Egg Exposure to Microwave Radiation and Magnetic Field1

Abstract We determined the effects of microwave radiation and static magnetic field on the gene activity in Drosophila by measuring the dimensions of puffing the salivary gland polytene chromosomes of Drosophila melanogaster Meigen following exposure of eggs to the radiation and magnetic field. Drosophila eggs were exposed to either microwave radiation of 36.64 GHz frequency and 1 W/m2 intensity for 30 s, a static magnetic field of 25 mT for 5 min, or both. The diameter of puffs was measured in squashed salivary gland preparations extracted from larvae from those eggs as they entered the prepupal stage. The puffs measured were 50CD, 63F, 71CE, 72CD (chromosome 3L) and 82EF, 83E, 93D (chromosome 3R). Results demonstrated that (a) microwave radiation exposure decreased puffing activity in puffs 63F, 71CE, and 82 EF but had no effect on puffing at 72CD, 93D and 50CD; (b) exposure to magnetic fields only did not change puff activity, but magnetic field exposure appeared to enhance the impact of microwave rad...