Resonance Interference Research Articles

CRB2 Depletion Induces YAP Signaling and Disrupts Mechanosensing in Podocytes.

Focal Segmental Glomerulosclerosis (FSGS) is a histologic lesion caused by a variety of injurious stimuli that lead to dysfunction/loss of glomerular visceral epithelial cells (i.e. podocytes). Pathogenic mutations in CRB2, encoding the type 1 transmembrane protein Crumb 2 Homolog Protein, have been shown to cause early-onset corticosteroid-resistant nephrotic syndrome (SRNS)/FSGS. Here, we identified a 2-generation East Asian kindred (DUK40595) with biopsy-proven SRNS/FSGS caused by a compound heterozygous mutation in CRB2 comprised of the previously described truncating mutation p.Gly1036_Alafs*43 and a rare 9-bp deletion mutation p.Leu1074_Asp1076del. Because compound heterozygous mutations involving the truncating p.Gly1036_Alafs*43 variant have been associated with reduced CRB2 expression in podocytes and autosomal recessive SRNS/FSGS, we sought to define the pathogenic effects of CRB2 deficiency in podocytes. We show that CRB2 knockdown induces YAP activity and target gene expression in podocytes. It upregulates YAP-mediated mechanosignaling and increases the density of focal adhesion and F-actin. Using Elastic Resonator Interference Stress Microscopy (ERISM), we demonstrate that CRB2 knockdown also enhances podocyte contractility in a substrate stiffness-dependent manner. The knockdown effect decreases with increasing substrate stiffness, indicating impaired mechanosensing in CRB2 knockdown cells at low substrate stiffness. While the mechanical activation of CRB2 knockdown cells is associated with increased YAP activity, the enhanced cell contractility is not significantly reduced by the selective YAP inhibitors K-975 and verteporfin, suggesting that multiple pathways may be involved in mechanosignaling downstream of CRB2. Taken together, these studies provide the first evidence that CRB2 deficiency may impair podocyte mechanotransduction via disruption of YAP signaling in podocytes.

Recent Patents on Piano Tuning System

Piano tuning plays a very important role in piano playing and music education. Regular tuning can prolong the service life of the piano, improve the sound saturation, and make the sound more concentrated and full. Automated mechanical equipment, controllers, sensors, and other equipment are used to automatically tune pianos to solve the problems of human error, overtone resonance interference, string breakage, etc., occurring in manual tuning. To solve the above problems, based on the synthesis of related patents and research results, the patents on automatic tuning system and methods for modulating piano are introduced in detail. An automatic tuning system can replace manual tuning, simplify the complex process of tuning, and consider the problem of overtone interference caused by the vibration of the strings to improve the accuracy of tuning; it can, at the same time, perform real-time monitoring of the string tension, protecting the strings from breaking due to tuning. The automatic tuning system has a simple structure and a high degree of automation; its method is highly accurate and it can replace professional tuning technicians, being highly innovative and widely practical.

Frequency domain solution method for electromagnetic influence analysis on torsional vibrations

In electric motor-driven machines, mechanical torsional dynamics are nonlinearly coupled with the electrical system through the electromagnetic torque and the counter-electromotive force. In this paper, an approach based on small-signal linearization is proposed for modeling the steady-state torsional dynamics of the coupled system. Using the linearized model, resonance interference diagrams, torsional response, and stability can be evaluated rapidly across numerous operating points, while accurately accounting for the electromagnetic effects. The model is validated with conventional time-stepping simulations of two induction machines. An example analysis of a 3 MW motor-driven compressor train displays the modification of torsional properties due to the electromagnetic coupling effect and explains the mechanism of torsional destabilization. Finally, previously published measurements of a 37 kW motor test bench are considered to validate the instability of the elastic torsional mode predicted by the model.

In Situ Measurement of Urea Concentration With an In-Fiber SPR-MZI Sensor.

A fiber-optic urea sensor based on surface plasmon resonance (SPR) and Mach-Zehnder interference (MZI) combined principle was designed and implemented. By plating gold film on the single-mode-no-core-thin-core-single-mode fiber structure, we successfully excited both SPR and MZI, and constructed two parallel detection channels for simultaneously measurement of urea concentration and temperature. Urease was immobilized on the gold film by metal-organic zeolite skeleton (ZIF-8), which can not only fix a large number of urease to improve measurement sensitivity of urea, but also protect urease activity to ensure the sensor stability. Experimental results indicate that the designed urea sensor with temperature compensation function can detect urea solution with concentration of 1-9 mM, and the sensitivity is 1.4 nm/mM. The proposed measurement method provides a new choice for monitoring urea concentration in the field of medical diagnosis and human health monitoring.

Combined scheme for mitigating coupling interference in dual‐band shared‐aperture base station antenna

AbstractA dual‐band shared‐aperture antenna array is presented, involving a combined scheme to suppress mutual coupling interference. The proposed array is comprised of a low‐band (LB) antenna, a frequency selective surface (FSS), sixteen high‐band (HB) antennas, and a reflector. The LB antenna utilises electromagnetic transparent (ET) characteristics to minimise scattering interference, while the FSS isolates resonance interference and port signal interference. The combined scheme integrates the benefits of both the ET antenna and FSS to suppress mutual coupling interference effectively. A prototype of the proposed antenna was fabricated and measured, operating at 1.7–2.7 GHz and 3.3–3.9 GHz. The simulated and measured results demonstrate stable patterns for both the LB antenna and the HB antennas. The cross‐band isolation is higher than 28 dB in the low‐band. With these advantages, the antenna array is suitable for base station applications.

Coherent light-emitting metasurfaces based on bound states in the continuum

Abstract An emergent need exists for solid state tunable coherent light emitters in the mid-infrared range for spectroscopy, sensing, and communication applications where current light sources are dominated by spontaneous emitters. This paper demonstrates a distinct class of coherent thermal emitters operating in the mid-infrared wavelength regime. The structure of the light source consists of a dielectric metasurface fabricated on a phononic substrate. In this study, we present the first implementation of off-Γ Friedrich–Wintgen bound states in the continuum at mid-infrared wavelengths suitable for developing the next generation of coherent light emitters. Numerical analysis of the emissivity spectrum reveals the interference of resonances leading to avoided crossings and the formation of Friedrich–Wintgen bound states in the radiation spectrum. Additionally, significant localized field enhancements are observed within the metasurface at operating wavelengths. The emissivity spectra measured by reflectivity and emission experiments exhibit temporally coherent emission peaks in the vicinity of the bound state in the continuum, the first such demonstration in the mid-infrared region for wavelengths longer than 7 µm. These results represent a new approach for significant advancement in realizing mid-infrared coherent light emitters with promising implications for future technologies.

A multi-modal microscope for integrated mapping of cellular forces and Brillouin scattering with high resolution

Mechanical forces and stiffness play key roles in the health and development of cells and tissue, but despite the physical connection between these quantities, they cannot be monitored in parallel in most cases. Here, we introduce a fully integrated microscope that combines a method for high-resolution cell force imaging (elastic resonator interference stress microscopy, ERISM) with non-contact mapping of the elastic properties of cells (via Brillouin microscopy). In order to integrate both techniques, we had to account for the strong back reflection on the surface of the microcavity used for ERISM measurements as well as the local destruction of the cavity under illumination for Brillouin microscopy measurements. Therefore, we developed an elastic optical microcavity with minimal absorption that can perform ERISM measurements without sustaining laser damage during Brillouin microscopy. Furthermore, an unequal-arm Michelson interferometer was designed to suppress the back reflection of the laser on the ERISM microcavity surface using division by amplitude interference to reduce the reflected light and enhance the Brillouin signal. We show the utility of our integrated microscope by simultaneously mapping cellular forces and Brillouin shifts in cultures of fibroblast cells.

Similar Tuning of Distortion-Product Otoacoustic Emission Ratio Functions and Cochlear Vibrations in Mice.

When elicited by two stimulus tones (at frequencies f1 and f2, f2 > f1), the amplitudes of specific distortion-product otoacoustic emission (DPOAE) components exhibit a characteristic bandpass shape as the ratio between f2 and f1 is varied. This bandpass shape has been attributed to various mechanisms including intracochlear resonance, suppression, and wave interference, and has been proposed to be related to cochlear frequency tuning. While human studies suggest modest correlations between psychophysical tuning and the tuning of DPOAE amplitude vs. f2/f1 ratio functions, a relationship between the latter and the tuning of cochlear mechanical responses has yet to be established. This was addressed here through direct comparisons of DPOAEs and cochlear vibrations in wild-type CBA/CaJ mice. DPOAEs were elicited using a fixed-f2, swept-f1 paradigm, and optical coherence tomography was used to measure displacements from cochlear locations with characteristic frequencies near f2. The tuning sharpness of 2f1-f2 DPOAE ratio functions was found to be remarkably similar to that of basilar membrane and/or tectorial membrane responses to single tones, with the tuning sharpness of all responses increasing similarly with decreasing stimulus level. This relationship was observed for f2 frequencies ranging from ~8 to 22 kHz. Intracochlear distortion products did not exhibit a bandpass shape as the f2/f1 ratio was varied, indicating that interference between distortion products traveling to the stapes may be responsible for the tuning of the DPOAE ratio function. While these findings suggest that DPOAE ratio functions could be used to noninvasively infer cochlear tuning, it remains to be determined whether this relationship holds in other species and for lower frequency regions.

Asymmetric Silicon Dimers Made by Single‐Shot Laser‐Induced Transfer Demultiplex Light of Different Wavelengths

AbstractNanofabrication technologies significantly influence the development of modern optical science. One of such technologies is laser‐induced transfer, which allows the creation of single Mie‐resonant spherical particles on a wide range of substrates. This study shows that this method can provide asymmetric dimers at the output: a single femtosecond pulse being focused on a silicon‐on‐insulator wafer results in appearing two nearly spherical particles of different sizes. The resulting dimers are characterized by scanning electron microscopy, elastic light scattering and Raman spectroscopy to gain insight into their structural properties. Back focal plane imaging and variable‐color evanescent‐wave illumination are then employed to measure the light scattering patterns from isolated dimers. Due to the interference of the excited resonances, the observed patterns are strongly asymmetric in a range of visible wavelengths, which is consistent with theoretical predictions. The results demonstrate the potential of asymmetric silicon dimers made by single‐shot laser‐induced transfer for color routing at visible light.

Growth and microwave properties of layered ferrogarnet structures

The ferrogarnet structures consisting from one- to three- layers of monocrystalline yttrium-iron garnet Y3Fe5O12 (YIG) films, two- layered YIG - La,Ga:YIG and two- layered {Y,Sm,Lu}3(Fe,Ga)5O12 -YIG structures were grown by liquid-phase epitaxy (LPE) method on gadolinium - gallium garnet Gd3Ga5O12 (GGG) substrates of (111) orientation. The obtained layered ferrogarnet structures were studied by the methods of ferromagnetic resonance (FMR) and magnetostatic wave (MSW) interference. The two- and three- layered YIG structures have a wide FMR line width (∆H). For the three- layered YIG structures with the total thickness of 68-102 μm ∆H = 5,7- 11,5 Oe. The line width ∆H = 0,34 – 1,22 Oe correspond to the two- layered (Y,Sm,La)3(Fe,Ga)5O12 – YIG structures with thicknesses from 3 to 65 μm. Individual layers in all structures are characterized by similar or different saturation magnetizations (4πMs).The frequency MSW separation in the YIG - La,Ga:YIG layered structure was observed. It was shown that the propagation losses of MSW in one- and two- layered structures increase with decreasing wavelength of MSW and transition to a two- layered structure.

Regulation of microwave absorbing performance of magnetic alloy/ferrite/carbon ternary composites by changing polydopamine-induced carbothermal reduction

Magnetic alloy/ferrite/nitrogen-doped carbon composites (CoFe/CoFe2O4/N–C) spheres were synthesized by controlled carbothermal reduction of Co-doped Fe2O3 nanospheres wrapped in polydopamine. Different dopamine hydrochloride dosages not only affected components and nanostructures, but also regulated the electromagnetic properties of CoFe/CoFe2O4/N–C composites. The results show that with the increase of dopamine hydrochloride dosage, graphitic degree of N-doped carbon layer would decrease after an initial increase, while the Ms values exhibit an opposite trend. All samples show similar μr spectra, and negative μ″ values can be obtained at high frequency, which should be related to eddy current and dielectric resonance. With the increment of polydopamine, εr would first increase due to generation of CoFe and the increase in graphitic degree, and then decrease owing to the agglomeration of spherical particles. Further research on microwave absorption shows that RL peak frequency coincides with the frequency of perfect impedance matching when good impedance matching has been achieved across a wide range of frequencies. Thanks to the synergistic effects of conduction loss, interfacial polarization, dipole polarization, natural resonance, eddy current, and complete interference cancellation, S-100 has a wide effective absorption bandwidth of 4.88 GHz at 2.0 mm and a low RL peak value of −70.48 dB at 1.95 mm. This work could offer new insights into multi-component magnetic MAMs design and illuminate the relationships between reflection loss, impedance matching, interference cancellation, phase composition, and composite structure.

Resonant tunneling and quantum interference of a two-spin system in silicon tunnel FETs

We investigated the resonant tunneling of a two-spin system through the double quantum dots in Al–N-implanted silicon tunnel FETs (TFETs) by electrical-transport measurements and Landau–Zener–Stückelberg–Majorana interferometry with and without magnetic fields. Our experimental results revealed the coexistence of spin-conserving and spin-flip tunneling channels in the two-spin system in non-zero magnetic fields. Additionally, we obtained the spin-conserving/spin-flip tunneling rates of the two-spin system through the double quantum dots in the TFET. These findings will improve our understanding of the two-spin system in silicon TFET qubits and may facilitate the coherent control of quantum states through all-electric manipulation.

Nonreciprocal Fano resonance enhanced unidirectional scattering by subwavelength magnetic meta-atoms

Superscattering effect of subwavelength particles has been intensively investigated due to the broad range of potential applications and the crucial role in understanding light–matter interactions, which is usually achieved by the superposition of multipolar resonances. Nonetheless, for the particles with intrinsic magnetic response the multipolar resonances cannot be completely superimposed due to the breaking of time-reversal symmetry under a bias magnetic field, resulting in substantially different scattering behaviors as is certain. We demonstrate an enhanced unidirectional scattering by the subwavelength magnetic “meta-atoms”, which is triggered by the formation of nonreciprocal Fano resonance arising either from the interference of Mie resonances associated with the double angular momentum channels (AMCs) at lower frequency or from the combinational interaction of Mie resonances associated with the triple AMCs at higher frequency. To identify the connection between the nonreciprocal Fano resonance and the unidirectional scattering, the fundamental rules are established to characterize the performance of nonreciprocal effect. The present research can be extended to the optical regime by considering magneto-optical materials and also instructive for the nonreciprocal photonics and potential applications.

The isothermal Boltzmann–Gibbs entropy reduction affects survival of the fruit fly Drosophila melanogaster

To the best of our knowledge, this is the first experimental evidence of the effect of isothermal changes in entropy on a living organism. In greater detail, the effect of the reduction of the total Boltzmann–Gibbs entropy (S) of the aquatic environment on the survival rate and body mass of the fruit fly Drosophila melanogaster was investigated. The tests were carried out in standard thermodynamic states at room temperature of 296.15 K and ambient atmospheric pressure of 1 bar. Two variants of entropy reduction (ΔS) were tested for ΔS = 28.49 and 51.14 J K−1 mol−1 compared to the blind and control samples. The entropy level was experimentally changed, using the quantum system for isothermal entropy reduction. This system is based on quantum bound entanglement of phonons and the phenomenon of phonon resonance (interference of phonon modes) in condensed matter (Silicon dioxide (SiO2) and single crystals of Silicon (Si0), Aluminum (Al0) plates (“chips”), glass, and water). All studied organisms were of the same age (1 day). Mortality was observed daily until the natural death of the organisms. The investigations showed that changes in the Boltzmann–Gibbs entropy affected the survival and body mass of the fruit flies. On the one hand, the reduction in entropy under isothermal conditions in the aquatic environment for ΔS = 28.49 J K−1 mol−1 resulted in an extension of the lifespan and an increase in the body mass of female fruit flies. On the other hand, the almost twofold reduction in this entropy for ΔS = 51.14 J K−1 mol−1 shortened the lives of the males. Thus, the lifespan and body mass of flies turned out to be a specific reaction of metabolism related to changes in the entropy of the aquatic environment.

Why Sonochemistry in a Thin Layer? Constructive Interference.

Sonochemistry in a thin fluid layer has advantages of no visible cavitation, no turbulence, negligible temperature changes (≲1 °C), low power transducers, and transmissibility (sound pressure amplification) of ≳106. Unlike sonochemistry in semi-infinite fluids, resonance and so constructive interference of sound pressure can be established in thin layers. Constructive interference enables substantial amplification of sound pressure at solid fluid interfaces. Fluid properties of sound velocity and attenuation, oscillator input frequency, and thin fluid layer thickness couple to established resonance in underdamped conditions. In thin layer sonochemistry (TLS), thin layers are established where ultrasonic wavelength and oscillator-interface separation are comparable, about a centimeter in water. Solution of a one dimensional wave equation identifies explicit relationships between the system parameters required to establish resonance and constructive interference in a thin layer.

U-fiber-based biosensor for temperature-compensated acetylcholine-specific measurement.

This paper presents a U-fiber-based biosensor to achieve temperature-compensated acetylcholine-specific measurement. The surface plasmon resonance (SPR) and multimode interference (MMI) effects are simultaneously realized in a U-shaped fiber structure for the first time, to the best of our knowledge. The experimental results show refractive index (RI) sensitivities of 3042 and 2958 nm/RIU and temperature sensitivities of -0.47 and -0.40 nm/°C for the MMI and SPR, which are greatly improved compared with the traditional structure. Simultaneously, a sensitivity matrix for detecting two parameters is introduced to solve the problem of temperature interference of biosensors based on RI changes. Label-free detection of acetylcholine (ACh) was achieved by immobilizing acetylcholinesterase (AChE) on optical fibers. The experimental results show that the sensor can realize the specific detection of acetylcholine and has good stability and selectivity, and the detection limit of the sensor is 30 nM. The sensor has the advantages of simple structure, high sensitivity, convenient operation, direct insertion into small spaces, temperature compensation, etc., which provide an important supplement to traditional fiber-optic SPR biosensors.

Dual-Band Shared-Aperture Base Station Antenna Array Based on 3-D Chokes

A novel structure for suppressing cross-band scattering interference in dual-band dual-polarized base station antenna arrays has been proposed. To alleviate the radiation pattern distortion of the high-band (HB) element caused by the low-band (LB) element, the LB radiator was loaded with 3-D chokes to suppress its scattering in the HB. In addition, when the LB element is excited, the resonance interference of the HB element to the LB element can be solved by the method of path extension. The array structure is composed of an LB element operating at 0.69–0.96 GHz (| <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | < −14 dB) and two columns of HB elements operating at 1.7–2.7 GHz. The simulation and experimental results of the array show that the loading of the 3-D chokes effectively suppresses the scattering interference in the LB element and restores the radiation patterns of the HB subarray, proving the effectiveness of this novel structure.

Optical fiber sensor based on SPR and MZI for seawater salinity and temperature measurement

Simultaneous detection of seawater salinity and temperature is conductive to study the state of seawater more intuitively. In this manuscript, a sensor for seawater salinity and temperature simultaneous measurement based on surface Plasmon resonance (SPR) and Mach-Zehnder interference (MZI) is put forward. The sensor forms MZI by fusing multimode fiber at both ends of hollow core fiber, SPR is formed by gold plating on one side of the hollow core fiber, and then MZI and SPR are coupled in a sensing structure. Experimental results reveal that the sensitivity of seawater temperature is −316.72 pm/℃ with temperature changing from 20 ℃ to 45 ℃, and the sensitivity of seawater salinity is 429.72 pm/‰. The proposed sensor overcomes the measurement error caused by the spatial position difference of cascade sensors, and provides a new idea for double parameter detection. What’s more, the sensor presents the advantages of small volume, simple fabrication and excellent performance.

Quantum-Path-Resolved Attosecond High-Harmonic Spectroscopy.

Strong-field ionization of molecules releases electrons which can be accelerated and driven back to recombine with their parent ion, emitting high-order harmonics. This ionization also initiates attosecond electronic and vibrational dynamics in the ion, evolving during the electron travel in the continuum. Revealing this subcycle dynamics from the emitted radiation usually requires advanced theoretical modeling. We show that this can be avoided by resolving the emission from two families of electronic quantum paths in the generation process. The corresponding electrons have the same kinetic energy, and thus the same structural sensitivity, but differ by the travel time between ionization and recombination-the pump-probe delay in this attosecond self-probing scheme. We measure the harmonic amplitude and phase in aligned CO_{2} and N_{2} molecules and observe a strong influence of laser-induced dynamics on two characteristic spectroscopic features: a shape resonance and multichannel interference. This quantum-path-resolved spectroscopy thus opens wide prospects for the investigation of ultrafast ionic dynamics, such as charge migration.

Analysis of the fine-mesh subgroup method and its feasible improvement

The fine-mesh subgroup method (FSM) is proposed to treat the significant resonance self-shielding effect both effectively and accurately. Similar to the ultra-fine group method, the fine-mesh subgroup method adopts a fine group structure on the resonance energy range to avoid the extra resonance interference effect correction. To improve the efficiency, on the one hand, the one-group micro-level optimization is adopted, so the subgroup fixed-source equations will be only calculated on a certain number of pre-determined subgroup levels, and an interpolation process is employed to obtain the actual subgroup flux. On the other hand, the slowing-down calculation is carried out for group condensation for multigroup transport calculation. The main theory and feasible improvements of the fine-mesh subgroup method are analyzed in this paper. Several pin cell and lattice problems are applied to test the performance of the fine-mesh subgroup method, and the particle swarm optimization method is adopted to find the better group structure. The numerical results indicate a good performance both for accuracy and efficiency.