Polarization Basis Research Articles

ETS1 governs pathological tissue-remodeling programs in disease-associated fibroblasts.

Fibroblasts, the most abundant structural cells, exert homeostatic functions but also drive disease pathogenesis. Single-cell technologies have illuminated the shared characteristics of pathogenic fibroblasts in multiple diseases including autoimmune arthritis, cancer and inflammatory colitis. However, the molecular mechanisms underlying the disease-associated fibroblast phenotypes remain largely unclear. Here, we identify ETS1 as the key transcription factor governing the pathological tissue-remodeling programs in fibroblasts. In arthritis, ETS1 drives polarization toward tissue-destructive fibroblasts by orchestrating hitherto undescribed regulatory elements of the osteoclast differentiation factor receptor activator of nuclear factor-κB ligand (RANKL) as well as matrix metalloproteinases. Fibroblast-specific ETS1 deletion resulted in ameliorated bone and cartilage damage under arthritic conditions without affecting the inflammation level. Cross-tissue fibroblast single-cell data analyses and genetic loss-of-function experiments lent support to the notion that ETS1 defines the perturbation-specific fibroblasts shared among various disease settings. These findings provide a mechanistic basis for pathogenic fibroblast polarization and have important therapeutic implications.

Implement quantum tomography of polarization-entangled states via nondiffractive metasurfaces

Traditional optical elements, such as waveplates and polarization beam splitters, are essential for quantum state tomography (QST). Yet, their bulky size and heavy weight are prejudicial for miniaturizing quantum information systems. Here, we introduce nondiffractive silicon metasurfaces with high transmission efficiency to replace the traditional optical elements for QST of polarization-entangled states. Two identical silicon metasurfaces are employed, and each metasurface comprises four independent districts on a micrometer scale. The unit cell of each district consists of two silicon nanopillars with different geometrical sizes and orientation angles, and the interference of the scattered waves from the nanopillars leads to a single output beam from the district with a specific polarization state with a transmission efficiency above 92%. When the two-photon polarization-entangled state shines on different districts of two metasurfaces, each photon of the photon pair interacts with the local nanopillars within the district, and the two-photon state is projected onto 16 polarization bases for state reconstruction. We experimentally demonstrate the reconstruction of four input Bell states with high fidelities. This approach significantly reduces the number of conventional optical components in the QST process and is inspiring for advancing quantum information technology.

METHOD FOR SPATIAL POLARIZATION COMPENSATION OF JAMMING

Context. To protect radars from active noise interference (jamming) acting along the side lobes of the antenna pattern, spatial signal filtering is used, which is realized by using diversity reception of the useful signal and interference. In this case, the difference in the directions of interference and signal makes it possible to compensate for interference and detect a useful signal. However, in the case where the source of interference is in the main lobe, the differences between the desired signal and the interference are reduced. This leads to significant distortion of the antenna main lobe pattern. As a result, the accuracy of angular coordinates measurement deteriorates, as well as the sensitivity of the receiving radar device. The article proposes a new method for spatial polarization processing of radar signals, which provides compensation for active noise interference both as from the directions of the side lobes and from the direction of the main beam of the antenna pattern. Objective. The goal is to develop a method for spatial polarization processing of radar signals under the influence of active noise interference both along the side lobes of the antenna pattern and along the main lobe. Method. The method is implemented by using structural adaptation of the noise protection device, depending on the direction of the interference. In this case, the control signal for structural adaptation is formed according to the magnitude of the current spatial filter weighting coefficient value. Results. A block diagram of a spatial polarizing filter which provides compensation for active noise interference acting both on the side lobes and on the main lobe of the radar antenna pattern. The mathematical model of the compensation unit that implements the structural adaptation of the spatial polarization filter has been developed. Under the conditions of the first special polarization basis, the efficiency of noise suppression acting along the main lobe of the antenna pattern is estimated. Conclusions. The scientific novelty of the research is the development of a new method of spatial polarization processing of radar signals under difficult conditions of radar operation under massive active noise interference. The practical significance of the research is in the development of a block diagram of a spatial polarizing filter that provides compensation for interference both from the direction of the side lobes and from the direction of the main lobe of the antenna pattern. The mathematical model of the filter has been developed. The efficiency of noise suppression under the conditions of the first special polarization basis is estimated.

Structure dependence of dielectric properties in Ca-doped bismuth magnesium niobate pyrochlores

The cubic pyrochlore Bi1.5MgNb1.5O7 (BMN) materials have large permittivity, good temperature stability, and extremely low dielectric loss. The structure and dielectric properties of Bi1.5Mg1−xCaxNb1.5O7 (BMCN, x = 0.0–0.5) are discussed systematically. All the samples except x = 0.5 were found that the dominant crystalline phase was cubic pyrochlore structure. The BMN (x = 0.0) cubic pyrochlore phase contained little impurity Mg4Nb2O9. Although Ca-doping inhibited the formation of the impurity phase Mg4Nb2O9, excessive Ca-doping (x ≥ 0.4) led to another second phase CaBi2Nb2O9 in BMCN structure. The substitution of Ca2+ brought about the reduction of structure disorder which were caused by abnormal cell shrinkage. It evidenced that Ca2+ ions are prone to substitute Mg2+ ions on A-site, then take on the B-site when the more Ca2+ ions doping in the pyrochlores. The permittivity of doped BMCN (x = 0.1–0.5) was smaller than that of BMN, and decreased with the increase of Ca2+ doping. The dielectric loss of doped BMCN increased due to the lattice defects caused by larger Ca2+ substitution for Mg2+, and the existence of the second phase with x = 0.4–0.5. The temperature dependence of the dielectric properties become unstable by Ca-doping. The Ca2+ substitution led to a closer association of BO6 octahedra, which had adverse impact on temperature stability of BMCN (x = 0.1–0.3). The coexistence of the second phase with positive temperature coefficient improved the dielectric temperature stability of the BMCN (x = 0.4–0.5). The dielectric loss was interpreted on the basis of the interfacial polarization at the grain-boundary region, which would become sensitive to temperature/frequency.

Silver Ion-Induced Formation of Unprecedented Thorium Nonamer Clusters via Lacuna-Construction Strategy

Silver Ion-Induced Formation of Unprecedented Thorium Nonamer Clusters via Lacuna-Construction Strategy

Comparison of Circular and Linear Orthogonal Polarization Bases in Electromagnetic Field Parameters Measurement

Comparison of Circular and Linear Orthogonal Polarization Bases in Electromagnetic Field Parameters Measurement

Electromembrane extraction using biodegradable deep eutectic solvents and agarose gel as green and organic solvent-free strategies for the determination of polar and non-polar bases drugs from biological samples: A comparative study

Two modes of electromembrane extraction (EME) were evaluated in this work, one using deep eutectic solvents (DESs) as liquid membrane, and another was gel electromembrane extraction (G-EME) based on solid agarose membrane. Both EME modes have eliminated organic solvents and are recognized as green strategies. Unlike classic EME in which polypropylene membrane and organic extracting solvents play an essential role in the extraction process, new modes of EME are based on biodegradable membranes and aqueous extracting solutions. Approaches of EME based on the new designs follow the green chemistry principles. Each mode of EME was evaluated for the determination of polar and non-polar bases drugs from human urine samples using high-performance liquid chromatography (HPLC) equipped with a diode array detector (DAD). EME using DES A was suitable for determining polar and non-polar bases drugs in a large polarity window. While extraction recoveries for all six drugs studied by G-EME were lower than EME using DES A. Comparing the two EME modes shows similar results in the analytical figures of merit. However, differences in extraction recoveries of the drugs by two EME modes were observed which is related to the difference in membranes structure. Our findings indicate that the differences between membranes properties used in two EME modes, including the permeability, hydrophilicity, hydrophobicity, and variety of interactions, are influencer factors on extraction efficiency. The two EME modes provided good linearity in the ranges of 16–100 and 19–100 μg. L−1 for G-EME and EME using DES A, respectively with (r2 > 0.993). Also, the detection limits (LODs) were 19–32 and 19–29 μg. L−1 for G-EME and EME using DES A, respectively.

Waveguide-based swappable hyperentangled photon states in a multi-period, postselection-free device

We explore the generation of four postselection-free, photonic hyperentangled states with the help of a multi-period waveguide device based on potassium titanyl phosphate. The output photons are emitted in the much-in-demand telecommunication wavelengths of 1550-nm and 1310-nm. The device geometry and design enables hyperentanglement in the spatial mode and polarization bases, through multi-period quasi-phase-matching involved in different spontaneous parametric downconversion processes. The spatially entangled part of these hyperentangled states are rendered swappable with the help of two embedded electro-optic phase modulators. A two-path design provides the flexibility of such a device in the choice of polarization-entangled states which is important in relevant experiments. Through the biphoton joint spectral amplitude, we decipher the parameters that make frequency correlation and further entanglement of the photon pairs feasible. Such maximally-hyperentangled biphoton states are useful in quantum information applications.

Electromembrane extraction – looking closer into the liquid membrane

Electromembrane extraction (EME) is a microextraction technique, where basic and acidic analytes are extracted as ionic species across a supported liquid membrane (liquid membrane) and into an acceptor solution. Extraction is based on an electrical field sustained across the liquid membrane, and selectivity is based on the direction and magnitude of the electrical field, the chemical composition of the liquid membrane, and pH in the sample and acceptor. EME shows potential for extraction of basic and acidic analytes from complex sample matrices, including biological fluids, environmental samples, food, and beverages. EME is green sample preparation, and provides efficient cleanup, high selectivity, and pre-concentration. Acceptor solutions are aqueous, and can be injected directly in liquid chromatography. We expect more activity with EME in the future. For this activity to be successful, understanding the fundamentals of EME is crucial. In this article, we are looking closer into the liquid membrane. We know extraction efficiency is highly affected by the chemical composition of the liquid membrane, but the fundamental understanding is limited. Therefore, selection of liquid membranes has been based on trial and error type of experiments up to date. In the last couple of years, however, the molecular understanding has improved. In light of this, we have reviewed liquid membranes reported in the literature; for nonpolar bases (log P ≥ 2), medium polar bases (0 ≤ log P < 2), polar bases (log P < 0), and correspondingly for acids. We have selected and presented a small number of liquid membranes, based on reported extraction performance and operational stability.

Polarization Optimization for the Detection of Multiple Persistent Scatterers Using SAR Tomography

The detection of multiple interfering persistent scatterers (PSs) using Synthetic Aperture Radar (SAR) tomography is an efficient tool for generating point clouds of urban areas. In this context, detection methods based upon the polarization information of SAR data are effective at increasing the number of PSs and producing high-density point clouds. This paper presents a comparative study on the effects of the polarization design of a radar antenna on further improving the probability of detecting persistent scatterers. For this purpose, we introduce an extension of the existing scattering property-based generalized likelihood ratio test (GLRT) with realistic dependence on the transmitted/received polarizations. The test is based upon polarization basis optimization by synthesizing all possible polarimetric responses of a given scatterer from its measurements on a linear orthonormal basis. Experiments on both simulated and real data show, by means of objective metrics (probability of detection, false alarm rate, and signal-to-noise ratio), that polarization waveform optimization can provide a significant performance gain in the detection of multiple scatterers compared to the existing full-polarization-based detection method. In particular, the increased density of detected PSs at the studied test sites demonstrates the main contribution of the proposed method.

Optical N -insulators: Topological obstructions to optical Wannier functions in the atomistic susceptibility tensor

A powerful result of topological band theory is that nontrivial phases manifest obstructions to constructing localized Wannier functions. In Chern insulators, it is impossible to construct Wannier functions that respect translational symmetry in both directions. Similarly, Wannier functions that respect time-reversal symmetry cannot be formed in quantum spin Hall insulators. This molecular orbital interpretation of topology has been enlightening and was recently extended to topological crystalline insulators which include obstructions tied to space group symmetries. In this article, we introduce a new class of two-dimensional topological materials known as optical $N$-insulators that possess obstructions to constructing localized molecular polarizabilities. The optical $N$-invariant $N\in\mathbb{Z}$ is the winding number of the atomistic susceptibility tensor $\chi$ and counts the number of singularities in the electromagnetic linear response theory. We decipher these singularities by analyzing the optical band structure of the material -- the eigenvectors of the susceptibility tensor -- which constitutes the collection of optical Bloch functions. The localized basis of these eigenvectors are optical Wannier functions which represent the molecular polarizabilities at different lattice sites. We prove that in a nontrivial optical phase $N\neq 0$, such a localized polarization basis is impossible to construct. Utilizing the mathematical machinery of $K$-theory, these optical $N$-phases are refined further to account for the underlying crystalline symmetries of the material, generating a classification of the topological electromagnetic phase of matter.

Determining the adsorption capacity and stability of Aflatoxin B1, Ochratoxin A, and Zearalenon on single and co-culture L. acidophilus and L. rhamnosus surfaces

This study assessed the adsorption capacity and stability of Aflatoxin B1 (AFB1), Ochratoxin A (OTA), and Zearalenon (ZEA) via Lactobacillus acidophilus ATCC 4356 and Lactobacillus rhamnosus ATCC 7469 individually and in combination with each other. Detoxifying efficiency depends on lactic acid bacteria species (hydrophobicity of cell wall), pH, temperature, time and mycotoxin type. According to the genetic algorithm results, the highest adsorption capacity (qe) of toxin for L. acidophilus + L. rhamnosus after washing with ethanol and chloroform decreased to (8.487 and 10.309 μg kg−1; AFB1), (9.464 and 9.014 μg kg−1; OTA), and (162.020 and 144.047 μg kg−1; ZEA), which is significantly less than before washing (9.872, 9.834, and 180.993) for AFB1, OTA, and ZEA after 24 h incubation at 37 °C. The surface hydrophobicity in turn toxin binding stability and capacity of the strains increased by increasing the incubation temperature from 27° to 37°C after 24 h. The affinity of AFB1 and OTA toxins to surface of LAB showed the most and the least content. For investigation of the stability binding of the AFB1, OTA and ZEA on LAB surfaces, toxin+LAB complexes were washed with solvents of different polarities. The bacteria–toxin complex stability showed the trend AFB1 > OTA> ZEA for toxin release in ethanol and ZEA> OTA> AFB1 for chloroform based on the difference in their polarity. Practical applicationIn the present study, the investigation of the efficiency of AFB1, OTA and ZEA adsorption on single and co-culture L. acidophilus and L. rhamnosus, on the basis of bacterial cell wall hydrophobicity and toxin polarity was studied. Food composites can have polarity differences that affect the stability of the toxin-bacteria interaction. Therefore, the monitoring of the LAB + mycotoxins capacity and stability through washing with solvents of different polarities, modeling the AFB1, OTA and ZEA binding capacity and stability before and after washing at different dough proofing times and temperatures has been investigated.

Broadband real-time full-stokes polarimetry by multi-tasking geometric phase element array

Polarization is a fundamental physical dimension of electromagnetic waves. However, experimental determination of polarization states of light is inherently challenging and inconvenient due to the loss of phase information in conventional optical characterization. In particular, the Stokes parameters are a critical indicator to fully describe arbitrary polarization state, which, however, require multiple intensity measurements in three orthogonal polarization bases. Here, we design and experimentally demonstrate a multi-tasking geometric phase element array to unveil all Stokes parameters in one shot. Such a method is convenient, broad-band, real-time with compact size to accurately characterize the complex polarization states of coherent light, which may find visionary applications in structured light microscopy, polarizable quantum computation, and communication, etc.

Enhancing SEM signature via bistatic radar configuration of small bisectors

The paper assesses the feasibility of finding bistatic directions of minimum bisectors subject to resonant frequency and polarisation diversities to improve the robustness of the resonance signature when extracted from the late time radar response. The general approach consists of three assessments, where the first assessment utilises the scattering frequency data (non-coherent) to determine if there are bistatic directions of small bisectors per reference resonant frequency and polarisation basis. The second assessment evaluated the correlation between the two targets' incident and scattering directions and confirmed that some directions enhanced the discriminative potential. The third assessment utilised the cumulative sum and the extracted resonant distribution from the time data (coherent) of the bistatic directions to determine the degree of signature enhancement by using a minimum error criterion between the reference and extractable mode frequencies with onset shift. The assessments were qualitative and concluded that the third resonance with a left circular basis could outperform other resonants in discriminative potential. Henceforth, the bistatic configuration improves the strength of this most discriminative resonant mode to allow the maximum utilisation of the SEM signature in the identification operation of aircraft targets.

Controllable Polarization and Diffraction Modulated Multi‐Functionality Based on Metasurface

AbstractDiffraction gratings are crucial optical elements in various optical systems, which can realize tailored diffraction energy distributions as well as phase modulations based on Fourier series. Meanwhile, the polarization gratings can produce arbitrarily specified polarization states on a set of desired diffraction orders for realizing polarimeter. However, simultaneously and independently tailoring the encoded phase profiles and polarization states in different diffraction orders has not been investigated previously. Here, a dielectric metasurface with the capability of generating different holographic images (generalized phase profiles) in different diffraction orders with controllable polarization states is proposed. Such functionality is achieved by applying the double‐phase method into the metasurface design process for manipulating the complex amplitude distributions of two orthogonal polarization bases. Furthermore, in order to prove that the proposed design strategy is suitable to achieve complicated wavefront modulation in a straightforward and convenient manner, a vectorial holographic image with spatially continuous polarization distribution is also obtained without any iteration process. The proposed method may pave the way to achieve a variety of applications such as beam shaping, polarization imaging as well as multifunctional optical systems.

Generation and dynamic manipulation of frequency degenerate polarization entangled Bell states by a silicon quantum photonic circuit

A silicon quantum photonic circuit was proposed and realized for the generation and the dynamic manipulation of telecom-band frequency-degenerate polarization entangled Bell states. Frequency degenerate biphoton states were generated in four silicon waveguides by spontaneous four wave mixing. They were transformed to polarization entangled Bell states through on-chip quantum interference and quantum superposition, and then coupled to optical fibers. The property of polarization entanglement in generated photon pairs was demonstrated by two-photon interference under two non-orthogonal polarization bases. The output state could be dynamically switched between two Bell states, which was demonstrated by the simplified Bell state measurement. The experiment results indicated that the manipulation speed supported a modulation rate of several tens kHz, showing its potential on applications of quantum communication and quantum information processing requiring Bell state encoding and dynamic control.

Exploitation of sub-look analysis and polarimetric signatures for ship detection in PolSAR data

ABSTRACT Synthetic aperture radar (SAR) reveals a valuable contribution to ship detection due to its all-weather and all-illumination sensing capabilities. In this paper, a new polarimetric SAR (PolSAR) ship detector is proposed that jointly exploits sub-look scattering properties of point-like scatterers (i.e. ships) and polarimetric information. The detector, which is physically based on the concepts of coherent scatterers and polarimetric signatures, consists of four main steps: first, polarimetric signatures are extracted for each sub-look image; then, the correlation coefficient (CC) between the sub-look images is calculated for varying polarization bases; ship detection is performed by setting a threshold on the resulting CC image and finally, morphological filters are applied to delineate the contour of the detected ships and automatically generate the number of targets detected. The exploitation of polarimetric information through the polarimetric signatures, on one side provides more discriminative information about target and makes the detector more robust and accurate, on the other side, it increases the computation time. The detector’s performance is verified against actual L- and C-band PolSAR datasets. Experimental results demonstrate that the proposed detector outperforms state-of-the-art ones and it results in an area under the receiver operating characteristic (ROC) curve that ranges between 0.93 and 0.95.

Synthesis, characterisation and biological activities of mixed ligand oxovanadium (IV) complexes derived from N,N‐diethyl‐N′‐para‐substituted‐benzoylthiourea and hydrotris(3,5‐dimethylpyrazolyl)borate

AbstractA series of oxovanadium (IV) complexes namely, [Tp*VOL1], [Tp*VOL2], [Tp*VOL3], [Tp*VOL4] and [Tp*VOL5] (where Tp = hydrotris(3,5‐dimethylpyrazolyl)borate, HL1 = 1‐benzoyl‐3,3‐diethylthiourea, HL2 = 1‐(4‐chlorobenzoyl)‐3,3‐diethylthiourea, HL3 = 1,1‐diethyl‐3‐(4‐methoxybenzoyl)thiourea, HL4 = 1,1‐diethyl‐3‐(4‐nitrobenzoyl)thiourea, HL5 = N‐(diethylcarbamothioyl)biphenyl‐4‐carboxamide) were prepared and characterised on the basis of mass spectrometry, elemental analysis and spectroscopy techniques (IR, UV–Vis and electron paramagnetic resonance, EPR) and mass spectrometry. The crystal structure of [Tp*VOL3] was elucidated from single crystal X‐ray diffraction study and the crystals adopted a triclinic system with a P‐1 (Z = 2) space group and unit cell parameters of a = 10.4953(4), b = 11.5290(5) and c = 15.0656(7) Å. The cyclic voltammetry showed a reversible oxidation of V (IV)/V(V) at about 0.50 V (vs Fc+/Fc). The HOMO and LUMO of benzoylthiourea were established by theoretical calculation based on DFT level using B3LYP method and a double numeric plus polarisation (DNP) basis set. The in vitro tests for antimicrobial activity showed that the complexes have a moderate inhibitory effect. The complex [Tp*VOL1] exhibited cytotoxic activity against the human hepatocellular carcinoma cell line (HepG2) at the concentration of 20 mg ml−1. However, no cytotoxic activity was observed against the Chang liver cells.

Synthesis, spectroscopic, DFT calculations, biological activities and molecular docking studies of new isoxazolone, pyrazolone, triazine, triazole and amide derivatives

Ethyl-2-cyano-2-(2-(3-nitrophenyl)hydrazono)acetate was synthesized and used as a versatile reagent for the synthesis of different heterocyclic compounds such as isoxazolone, pyrazolone, triazine, triazole and amide derivatives via its reactions with different nucleophiles. Conventional, microwave and grinding techniques were used for synthesis of the newly isolated derivatives. Various physical parameters were calculated from the percentage yield and reaction time in order to compare between the three techniques. The reported compounds were characterized by elemental analyses and different spectroscopic tools such as IR, 1H NMR, 13C NMR and mass spectrometry. The optimized molecular geometries of some selected compounds were investigated using the density functional theory (DFT/B3LYP) method with the use of double zeta plus polarization basis set 6–31 G (d,p) for the C, H, N, O and S atoms. The quantum global reactivity descriptors were also calculated and discussed. The antibacterial and cytotoxicity screening of those compounds were performed to determine their therapeutic potential. Molecular docking of the compounds was also examined. The different biological studies as well as the molecular docking were correlated to each other, and supported that the compounds could bind to DNA, possibly, via intercalative mode and showed a various DNA binding potency.

Ab initio calculations of electronic band structure of CdMnS semimagnetic semiconductors

This work is devoted to theoretical investigations of Cd1-xMnxS semimagnetic semiconductors (SMSC). The purpose of this work was to calculate the electronic band structure of ideal and defective Cd1- xMnxS SMSC in both antiferromagnetic (AFM) and ferromagnetic (FM) phases. Ab initio, calculations are performed in the Atomistix Toolkit (ATK) program within the Density Functional Theory (DFT) and Local Spin Density Approximation (LSDA) on Double Zeta Double Polarized (DZDP) basis. We have used Hubbard U potential UMn = 3.59 eV for 3d states for Mn atoms. Supercells of 8 and 64 atoms were constructed. After the construction of Cd1-xMnxS (x = 6.25 %; 25 %) supercells and atom relaxation and optimization of the crystal structure were carried out. Electronic band structure and density of states were calculated, the total energy has been defined in antiferromagnetic (AFM) and ferromagnetic (FM) phases. Our calculations show that the band gap increases with the increase in Mn ion concentration. It has been established that Cd or S vacancy in the crystal structure leads to the change of band gap, Fermi level shifts towards the valence or conduction band.