Polarization Conditions Research Articles

An Experimental Investigation on Polarization Process of a PZT-52 Tube Actuator with Interdigitated Electrodes.

The manipulator is the key component of the micromanipulator. Using the axial expansion and contraction properties, the piezoelectric tube can drive the manipulator to achieve micro-motion positioning. It is widely used in scanning probe microscopy, fiber stretching and beam scanning. The piezoceramic tube actuator used to have continuous electrodes inside and outside. It is polarized along the radial direction. There are relatively high polarization voltages, but poor axial mechanical properties. A new tubular actuator is presented in this paper by combining interdigitated electrodes and piezoceramic tubes. The preparation, polarization and mesoscopic mechanical properties were investigated. Using Lead Zirconate Titanate (PZT-52) as a substrate, the preparation process of interdigitated electrodes by screen printing was studied. For initial polarization voltage determination, the local characteristic model of the actuator was extracted and the electric field was analyzed by a finite element method. By measuring the actuator’s axial displacement, we measured the actuator’s polarization effect. Various voltages, times and temperatures were evaluated to determine how polarization affects the actuator’s displacement. Optimal polarization conditions are 800 V, 60 min and 150 °C, with a maximum displacement of 0.88 μm generated by a PZT-52 tube actuator with interdigitated electrodes. PZT-52 tube actuators with a continuous electrode cannot be polarized under these conditions. The maximum displacement is 0.47 μm after polarization at 4 kV. Based on the results, the new actuator has a more convenient polarization process and a greater axial displacement from an application standpoint. It provides technical guidance for the preparation and polarization of the piezoceramic tube actuator. There is potential for piezoelectric tubular actuators to be used in a broader range of applications.

(Digital Presentation) Bipolar Electrochemical Impedance Spectroscopy for Corrosion Monitoring of Steel Reinforced Cementitious Structural Components

Bipolar electrochemical impedance spectroscopy (BPEIS) was previously explored as a potential nondestructive method for detecting corrosion of steel in post-tensioned tendons which are used as reinforcing structural elements in segmental bridge construction. The tendons are composed of a grout-filled cylindrical plastic duct that contains high-strength steel strands. A proof of concept was demonstrated by experiments performed on tendons with passive and corroded strands and through finite-element simulations of the indirect impedance response1. Further work showed that bipolar impedance was sensitive to local corrosion in field tendons if the measurement is obtained near the corroding region2. This work further scrutinizes BPEIS as a corrosion monitoring method for reinforced cementitious structural components with direct comparison between corrosion damage estimates and actual metal loss.Bi-polar electrochemistry is a noncontact method in which a conducting material placed within an electric field induced by two feeder electrodes is indirectly polarized while maintaining charge neutrality such that the conducting material forms two poles, a positively charged pole which acts as the anode and negatively charge one that acts as the cathode. If the electric field is applied between the feeder electrodes under alternating current, the poles fluctuate between anode and cathode extremes corresponding to the direction of the induced field. Under such polarization conditions, the opportunity to assess the electrochemical impedance between the feeder electrodes is provided. The measured impedance includes the interfacial impedance of the feeder electrodes, the conducting material interface impedance, and the impedance of the conductor itself which can be assumed to be negligible. By placing two reference electrodes between the feeder electrodes, the interfacial impedance of the feeder electrodes can be eliminated from the measurement, thus allowing one to obtain an impedance reflective of the electrolyte impedance between the reference electrodes and the impedance of the conducting material interface.A finite element model is used to relate the measured impedance response to the impedance of the steel and cement interface and therefore the corrosion rate. The ability to accurately monitor the corrosion rate will be assessed by comparing the estimated corrosion damage obtained by integration of periodic estimates of corrosion rate to the actual damage. The role of a corrosion product layer, reinforcement geometry, and electrode configuration to the sensitivity of the measurement to corrosion rate will be described.[1] Alexander, C. L., & Orazem, M. E. (2020). Indirect electrochemical impedance spectroscopy for corrosion detection in external post-tensioned tendons: 1. Proof of concept. Corrosion Science, 164, 108331.[2] Alexander, C. L., & Orazem, M. E. (2020). Indirect impedance for corrosion detection of external post-tensioned tendons: 2. Multiple steel strands. Corrosion Science, 164, 108330.

Optimization of Pulsed Polarization Condition for Efficient Electrochemical CO2 Reduction

Introduction Massive emission of CO2 gas from fossil fuel combustion causes the severe global greenhouse effect. Electrochemical reduction of CO2 using renewable energy has been attractive due to its simple methodology, while the conversion efficiency may be lessened due to undesirable side reactions such as water decomposition. In this study, CO2 was covered to CO on Ag electrode in aqueous KHCO3 solution using potentiostatic pulse polarization, and optimal pulse condition to improve the conversion efficiency was explored. Experiment An electrochemical cell was composed of a cathode compartment containing an Ag working electrode (W.E.) and an Ag/AgCl reference electrode and an anode compartment containing a Pt counter electrode. Two compartments were separated by a Nafion membrane. An Ag-W.E. was mechanically polished and potentiostatically pulse-polarized in a CO2-saturated 0.1 M KHCO3 solution to form CO. After some polarization period, the conversion efficiency ( η=[CO]/([CO]+[H2]) ) of CO2 to CO was evaluated by using gas chromatography as a function of various parameters such as cathodic polarization potential (E c) and time (t c), rest potential (E a) and time (t a), KHNO3 concentration, etc. Result and discussion When E c was varied, the highest η was obtained around –1.5 to –1.6 V. When t c was varied at E c = –1.6 V, the highest η was obtained around t c = 3 s, as shown in Fig. 1. The t a did not affect η. These results reveal that the t c influences the conversion efficiency viacontrolling the diffusion layer thickness of reactants such as CO2 molecular. The highest η at the optimal pulse condition was ca. 0.9 and is comparable to the value obtained by the previous work using ionic liquid solution (T. Oguma et al., Electrochemistry, 88 (2020) 451–456). Fig. 1. Relationship between the cathodic polarization time t c and reduction efficiency Figure 1

Synthesis of Nanostructures Using Gas-Diffusion Electrodes

Gas diffusion electrodes (GDEs) intertwine an ionically conducting liquid and a gas with an electrically conducting solid, supporting electrochemical reactions involving constituents linked to the three phases (i.e., chemical species, electrons). GDEs are broadly used in electrochemical energy-conversion devices, such as fuel cells and metal-air batteries, as well as in electrolyzers aiming at chemical synthesis, like in the chlor-alkali industry, hydrogen peroxide production, CO2 conversions to fuels and fine chemicals, or N2 reduction to ammonia. Recently, the use of GDEs was pioneered for metal recovery and the synthesis of nanostructures, in a process named gas-diffusion electrocrystallization (GDEx).[1–4] A liquid solution containing dissolved metal or metalloid ions (e.g., Cu2+, Fe3+, As3+, PtCl2 −6) flows through an electrochemical cell equipped with a GDE, filling in its porosity. The gas (e.g., O2, O2 in air, CO2, etc.) percolates through a hydrophobic backing (e.g., PTFE) on the GDE. After the gas diffuses to the electrically conducting layer acting as an electrocatalyst (e.g., hydrophilic porous activated carbon), the gas is electrochemically reduced. For instance, by imposing specific cathodic polarization conditions (e.g., at −0.145 VSHE O2 is reduced producing H2O2, H2O and OH–). As the highly abundant hydroxyl ions accompanied by redox reactive species spread to the bulk electrolyte, a reaction front develops throughout the hydrodynamic boundary layer. This creates local saturation conditions at the electrochemical interface, where metal ions precipitate in metastable or stable phases, depending on the operational variables. When O2 is the oxidizing gas, GDEx has been explained with an oxidation-assisted alkaline precipitation mechanism.[4] Conversely, when CO2 is used, the reaction front, rich in reducing species, yields elemental nanoparticles.This centennial celebration talk will explain the underlying principles of GDEx, portray reflections on its design and scale-up, and substantiate some of the experimental merits achieved. It will include the GDEx: (a) synthesis of iron oxide nanoparticles with high control of their magnetic susceptibility[1]; (b) recovery and immobilization of arsenic into crystalline scorodite[2]; (c) synthesis of nanoparticles with novel magnetic ground states (e.g., spin liquids and spin glasses)[3]; (d) synthesis of libraries of electrochemically-active materials[5] and (e) formation of elemental nanoparticles of platinum group metals (PGMs).

Possible Atmospheric Water Vapor Contribution from Martian Swiss Cheese Terrain

Mars’s south polar residual cap (SPRC) is a several-meters-thick CO2 ice cap with a variety of features, including quasi-circular depressions known as “Swiss cheese” that may expose underlying water ice. Swiss cheese pits have been suggested as a source for the observation of unusually high water vapor during the southern summer of Mars Year (MY) 8 (1969). To evaluate this hypothesis, we map the current extent of Swiss cheese pits to estimate the contribution to atmospheric water vapor from sublimation from the pits. We use data from the Mars Reconnaissance Orbiter Context Camera to map individual features and use the Mars Climate Sounder to obtain surface temperatures to estimate areas of exposed water ice to infer the amount of water vapor sublimated under typical south polar summer atmospheric conditions. We find that there is a negligible impact on atmospheric water vapor from sublimation with the current coverage and temperatures of Swiss cheese terrain (0.2% of the SPRC at an average of ∼161 K). At current typical temperatures, complete removal of residual CO2 from 99% of the SPRC would be required to sublimate enough water vapor to reproduce the MY 8 observation. However, a modest increase in temperature (∼20 K) could lead to a dramatic increase in sublimation rate, such that only water ice over 2.6% of the SPRC area would recreate the MY 8 observation. >180 K surface water ice has been observed on Mars, but such temperatures are likely transient at the south pole over the past ∼30 Mars years.

Terahertz Vibrational Fingerprints Detection of Molecules with Particularly Designed Graphene Biosensors.

In this research, an arc I-shaped graphene sensing structure with multi-resonance characteristics is proposed for the simultaneous detection of vibrational fingerprints with spectral separation in the terahertz range. The resonant frequencies of the sensor can be dynamically tuned by changing the gate voltage applied to the graphene arrays. The two vibrational fingerprints of lactose molecules (0.53 THz and 1.37 THz) in the transmission spectrum can be enhanced simultaneously by strictly optimizing the geometrical parameters of the sensor. More importantly, these two resonant frequencies can be tuned precisely to coincide with the two standard resonances of the lactose molecule. The physical mechanism of the sensor is revealed by inspection of the electric field intensity distribution, and the advantage of the sensor, which is its ability to operate at a wide range of incident angles, has been demonstrated. The sensing performance of the structure as a refractive index sensor has also been studied. Finally, a double arc I-shaped graphene sensor is further designed to overcome the polarization sensitivity, which demonstrates excellent molecular detection performance under different polarization conditions. This study may serve as a reference for designing graphene biosensors for molecular detection.

DNAM-1 regulates the proliferation and function of T regulatory type 1 cells via the IL-2/STAT5 pathway

To explore the role of DNAM-1 in the activation, proliferation and function of type Ⅰ regulatory T cells (Tr1 cells). Anti-CD3/CD28 antibodies were used to stimulate mouse T cells derived from the spleen of wild-type (WT) mice, and the expression level of DNAM-1 in resting and activated Tr1 cells was evaluated with flow cytometry. Na?ve CD4+ T cells isolated by magnetic cell sorting from the spleens of WT mice and DNAM-1 knockout (KO) mice were cultured in Tr1 polarizing conditions for 3 days, after which CD25 and CD69 expressions were measured using flow cytometry. The induced Tr1 cells were labelled with CFSE and cultured in the presence of anti-CD/CD28 antibodies for 3 days, and their proliferative activity was analyzed. The expressions of IL-10 and p-STAT5 in DNAM-1-deficient Tr1 cells were detected before and after IL-2 stimulation. The expression level of DNAM-1 was significantly upregulated in CD4+ T cells and Tr1 cells after stimulation with anti-CD3/CD28 antibodies (P < 0.05). DNAM-1 knockout did not cause significant changes in the number or proportion of Tr1 cells, but but significantly increased the expression levels of the activation markers CD69 and CD25 (P < 0.05). Compared with WT Tr1 cells, DNAM-1-deficient Tr1 cells exhibited reduced proliferative activity in vitro (P < 0.05) with downregulated IL-10 production (P < 0.05) and decreased expressions of Il-10 and Gzmb mRNA (P < 0.05). In DNAM-1-deficient Tr1 cells, IL-2 stimulation significantly reduced IL-10 secretion level and the expression of p-STAT5 as compared with WT Tr1 cells. DNAM-1 participate in the activation and proliferation of Tr1 cells and affect the biological functions of Tr1 cells through the IL-2/STAT5 pathway.

Multi-spectroscopic characteristics of olive oil-based Quercetin nanoemulsion (QuNE) interactions with calf thymus DNA and its anticancer activity

Several types of biological functions have been reported for Quercetin, such as antioxidant and anticancer activities. The current study aimed to improve the solubility and stability of Quercetin’s nanoemulsions (QuNEs) produced under polar physiologic conditions and to clarify Quercetin’s interaction properties with calf thymus DNA (ctDNA) in its released form. The cytotoxicity of QuNE was analyzed by measuring the MTT assay in MCF-7 cells and caspase-9 gene expression in the HePG2 liver cancer cell line. Also, the ABTS antioxidant assay was performed for evaluating QuNE’s antioxidant activity. QuNE’s interaction with ctDNA was evaluated via running RLS and CD spectroscopy, viscometry, thermal denaturation, thermodynamic parameters (Van’t Hoff and Stern-Volmer diagrams), and molecular docking methods. The QuNE-released Quercetin significantly reduced viability of MCF-7 cells and induced caspase-9 up-regulation in HepG2 cancer cells. Further, compared with unreleased Quercetin, QuNE particles made complexes with ctDNA through hydrophobic interactions. The ΔH0, ΔS0, and binding constant (BC) indices for QuNE-ctDNA were measured at 68.36 KJ.mol−1, 308.42 J.mol-1K−1, and 0.04 × 104 and 2.49 × 104 M−1, respectively. Further, high antioxidant activity was measured for QuNE. QuNE was detected as the DNA groove binder agent. Considering QuNE’s ability in releasing Quercetin near ctDNA, it can be potentially used as an appropriate delivery transporting system which can successfully interact with DNA molecules in a groove binding manner to induce apoptotic effects.

Design and experimental measurements of single/dual mode tunable metasurfaces

The development of optoelectronic devices based on metasurfaces is becoming an emerging field. However, the performance of conventional metasurfaces based on metal array are determined by the structural design strategy, resulting in the optical response behaviors being solidified during the sample preparation process. Therefore, designing and developing metasurfaces with reconfigurable and actively modulated properties is an important way to expand the performance of optoelectronic devices. The tunability of phase change materials is an important component in the development of similar devices. A tunable metasurface that containing Si and GST arrays is proposed and measured. Based on the phase-change modulability of GST arrays, this metasurface shows the properties of single/dual-mode control, multi-level control, and continuous control of reflection. Finally, the effect of the incident angle of electromagnetic waves on the reflective properties of the metasurface is measured. Under the TE polarization condition, the increase of the incident angle has a weak effect on the reflection performance of the metasurface sample. Under TM polarization conditions, the MD resonance reflection peak is splited into two new reflection peaks. And the resonant properties (amplitude and resonant wavelength) of the new reflection peaks are incident angle tunable. Therefore, this all-dielectric metasurface reveals the potential to be applied in reconfigurable, high-efficiency, and multi-level controlled optoelectronic devices.

Cathodic Protection System of the Spiral Classifier at the KGHM Polska Miedź S.A. Ore Concentration Plant—Case Study of Commissioning and Control of Operating Parameters

The project involved designing, constructing and commissioning a cathodic protection system for a selected spiral classifier operating at the KGHM Polska Miedź S.A. Ore Concentration Plant (O/ZWR). The authors developed a concept and assumptions regarding the corrosion protection of a large industrial device using a cathodic protection system with an external power source. Pre-project studies included conducting a trial polarization of one of the 28 classifiers operating at O/ZWR. The obtained results enabled the determination of the protective current demand required and the selection of a target polarization device, ensuring the flow of current with an intensity that guarantees that the required corrosion protection level will be achieved. The ultimately installed cathodic protection system consisted of an external cathodic protection current source with maximum output parameters of 50V/20A, a power supply system and a polarization anode system. Elements for monitoring corrosion occurring during system operation were installed, which employed reference electrodes of zinc (Zn) and silver chloride (Ag/AgCl) to measure the potential of the structure under cathodic protection. Furthermore, resistive corrosion sensors were installed to measure the steel corrosion rate under polarization conditions, making it possible to assess the effectiveness of the protection. The system will also be equipped with a prototype system for remote monitoring of the operation of the protection system, enabling online observation and analysis of settings and temporary indicators influencing the ongoing corrosion processes.

Properties of novel 0–3 PZT/silicone resin flexible piezoelectric composites for ultrasonic guided wave sensor applications

Ultrasonic guided wave (UGW) technology based on piezoelectric sensors is considered a very promising technology for aircraft structural damage detection. Traditional piezoelectric sensors are made of lead zirconate titanate (PZT) ceramics, but their brittleness and hardness make them difficult to apply to curved structure surfaces. In this study, a novel 0–3 flexible piezoelectric composite was fabricated by dispersing PZT particles in silicone resin, and its performance for potential applications in UGW sensors was studied. The effects of polarization conditions, PZT volume fraction, and PZT powder size on the performance of the composite were investigated. The influence of ambient temperature on composite performance was discussed, and temperature adaptability experiments were conducted. The results show that the optimal poling process of 0–3 PZT/silicone resin piezoelectric composite has a poling time of 25 min, a poling electric field of 4 kV/mm, and a poling temperature of 100°C. When the sensor is required to meet the test strain range of 8,000 με, the composite should be fabricated with a PZT volume fraction of 50% and a powder size of 170∼212 μm to obtain optimal sensing sensitivity. At an ambient temperature range of -55–75°C, the fabricated piezoelectric composite sensor has good flexibility and sensitivity in detecting the guide wave signals. These research results provide a new flexible piezoelectric sensing technology for aircraft structural damage detection.

Performance optimization of electret air filter

With the rapid development of the society, the severe haze weather caused by particulate matters (PMs) occurs frequently. Electret air filters have been playing an important role in purifying the air and alleviating the pollution. In this work, electret air filters were fabricated based on the polypropylene (PP) materials to investigate their filtering performance to the PMs. First, the electret performance of the PP-based films was mainly focused on. The charge storage stability of the electret films was found to be associated with the material recipe and the electret technique. Introducing 1% of tourmaline into the isotactic PP can realize the best charge storage stability, while adding the graphene can weaken the charge stability. And the electret techniques including the high-temperature pre-aging and polarization at elevated temperature were adopted to optimize the charge storage performance. Then, based on the optimized electret materials and electret technique, the purification performance of the electret filter elements dependent on the polarization condition was evaluated. The present work can provide an optimization strategy to improve the performance of electret materials and electret air filters.

Hybrid Zinc Coating with CuO Nanocontainers Containing Corrosion Inhibitor for Combined Protection of Mild Steel from Corrosion and Biofouling

In this study, a multifunctional hybrid coating is designed for the combined protection of mild steel from corrosion and biofouling in aggressive salt water. This involves preparation of a pH-responsive-release system based on copper oxide (CuO) as a biocide, and the corrosion inhibitor Safranin loaded in polymeric nanocontainers by alternate adsorption of poly(acrylic acid) and poly(ethylenimine) on CuO nanoparticles in water solutions. By optimizing the conditions, i.e., pH and concentration, good stability of the suspensions and the loading amount of Safranin is achieved. The nanocontainers are electrodeposited as an intermediate layer in an ordinary zinc coating on steel (“sandwich-like” structure) from the water solution in order to minimize the effect of CuO dissolution. To highlight the role of Safranin in reducing steel corrosion, a second zinc coating containing CuO nanoparticles without a corrosion inhibitor is also examined. The surface morphology and corrosion behavior of the hybrid coatings are evaluated in a model corrosion medium (5% NaCl solution). Both coatings are found to improve the anticorrosion behavior of steel for a time interval of 55 days and at conditions of external polarization. It can be expected that the newly developed hybrid coatings would also demonstrate potential for marine applications due to the main characteristics of their components.

An efficient finite element method based on dimension reduction scheme for a fourth-order Steklov eigenvalue problem

AbstractIn this article, an effective finite element method based on dimension reduction scheme is proposed for a fourth-order Steklov eigenvalue problem in a circular domain. By using the Fourier basis function expansion and variable separation technique, the original problem is transformed into a series of radial one-dimensional eigenvalue problems with boundary eigenvalue. Then we introduce essential polar conditions and establish the discrete variational form for each radial one-dimensional eigenvalue problem. Based on the minimax principle and the approximation property of the interpolation operator, we prove the error estimates of approximation eigenvalues. Finally, some numerical experiments are provided, and the numerical results show the efficiency of the proposed algorithm.

Polarity-driven laminar pattern formation by lateral-inhibition in 2D and 3D bilayer geometries

Abstract Fine-grain patterns produced by juxtacrine signalling have previously been studied using static monolayers as cellular domains. However, analytic results are usually restricted to a few cells due to the algebraic complexity of non-linear dynamical systems. Motivated by concentric patterning of Notch expression observed in the mammary gland, we combine concepts from graph and control theory to represent cellular connectivity and behaviour. The resulting theoretical framework allows us to exploit the symmetry of multicellular bilayer structures in 2D and 3D, thereby deriving analytical conditions that drive the dynamical system to form laminar patterns, consistent with the formation of cell polarity by activator localization. Critically, the patterning conditions are independent of the precise dynamical details, thus the framework allows for generality in understanding the influence of cellular geometry and signal polarity on patterning using lateral-inhibition systems. Applying the analytic conditions to mammary organoids suggests that intense cell signalling polarity is required for the maintenance of stratified cell types within a static bilayer using a lateral-inhibition mechanism. Furthermore, by employing 2D and 3D cell-based models, we highlight that the cellular polarity conditions derived from static domains can generate laminar patterning in dynamic environments. However, they are insufficient for the maintenance of patterning when subjected to substantial morphological perturbations. In agreement with the mathematical implications of strict signalling polarity induced on the cells, we propose an adhesion-dependent Notch-Delta biological process that has the potential to initiate bilayer stratification in a developing mammary organoid.

Decolonising the school curriculum in an era of political polarisation

Recent consciously curated conditions of political polarisation have prevented English schools from taking even the first tentative steps towards decolonising the curriculum. Since returning to power in 2010, successive Conservative Secretaries of State for Education have resolved to restore traditional learning methods to English classrooms, championing the need for children to passively accept content chosen for them by government appointees who are answerable to political rather than to pedagogical priorities. This had already created an unsupportive political environment for transforming what children might learn, before such difficulties were magnified following the Brexit referendum of 2016. Decolonisation has increasingly been identified by Conservative Party strategists as one of their beloved wedge issues, something that can be used to stoke electorally expedient anger against ‘the Remainer elite’ among Leave-voting communities. Hopes for a serious debate about the principles of decolonisation were frustrated by the Johnson government hijacking the very mention of the word to use as evidence that the ‘woke’ brigade was running hopelessly out of control. The case for decolonising the English school curriculum has been subjected to a full-frontal populist culture-war attack on an educational establishment accused of refusing to allow children to see the good in their country.

Broad-Band Polarization-Insensitive Metasurface Holography with a Single-Phase Map.

The remarkable potential of metasurface holography promises revolutionary advancements for imaging, chip-integrated augmented/virtual reality (AR/VR) technology, and flat optical displays. The choice of constituent element geometry constrains many potential applications purveyed through polarization-independent optical response. The limited capabilities and degree of freedoms in commonly used meta-atoms restrict the design flexibility to break the conventional trade-off between polarization-insensitivity and bandwidth. Here, we propose a geometric phase-enabled novel design strategy to break this conventional trade-off. The proposed strategy ensures the realization of broad-band polarization-insensitivity through a simplified design procedure. An identical output wavefront manipulation is achieved by adjusting the phase delay freedom of geometric phase engineering under different incident polarization conditions. For proof of concept, a metahologram device is fabricated by an optimized complementary metal-oxide-semiconductor (CMOS)-compatible material of hydrogenated amorphous silicon (a-Si:H). This metahologram device reproduces the required hologram with high image fidelity and efficiency under different polarization scenarios of white light incidence. Due to the simple design strategy, low computational cost, and easy fabrication, the proposed technique can be an excellent candidate for realizing polarization-insensitive metahologram devices.

Secoisolariciresinol diglucoside-derived metabolite, enterolactone, attenuates atopic dermatitis by suppressing Th2 immune response

Atopic dermatitis (AD) is a severe inflammatory skin disease caused by a combination of genetic, immune, and environmental factors. Intestinal microbiome disorders and changes in the immune microenvironment are associated with AD. We observed that gut bacterial metabolite enterolactone (ENL) was significantly reduced in AD model mice. Notably, patients with early childhood-onset AD exhibited decreased sera ENL level compared to the healthy controls, and the ENL level was negatively correlated with the SCORAD index. Secoisolariciresinol-diglycoside (SDG) is a natural dietary lignan of flaxseeds that can be converted by intestinal bacteria to ENL. Repeated applications of 2,4-dinitrochlorobenzene (DNCB) were performed on the ear and dorsal skin of mice to induce AD-like symptoms and skin lesions. Oral administration of SDG significantly decreased serum IgE levels and limited skin inflammation in the DNCB-induced AD mice. In addition, SDG treatment strongly limited the Th2 responses in AD mice. Moreover, we demonstrated that the IL-4 production was significantly suppressed by ENL under Th2 polarization conditions via the JAK-STAT6 signaling pathway in a concentration-dependent manner. We concluded that SDG and its derived metabolite ENL ameliorated AD development by reducing the Th2 immune response. These results suggested that SDG and ENL might be exploited as potential therapeutic candidates for AD treatment.

DJ-1 controls T cell differentiation and osteoclastogenesis in rheumatoid arthritis

Herein, we investigated the effect of DJ-1 on helper T cell differentiation, fibroblast-like synoviocyte (FLS) activation, and osteoclastogenesis in rheumatoid arthritis (RA). Serum and synovial fluid (SF) of RA and osteoarthritis (OA) patients were collected, and DJ-1 and H2O2 levels were investigated. CD4+ cells from peripheral blood mononuclear cells (PBMCs) were cultured under type 17 helper T cell (Th17) polarization conditions, and CD4+ T cell differentiation, pro-inflammatory cytokine levels, and soluble receptor activator of nuclear factor kappa-Β ligand (RANKL) were assessed. RA-FLSs were stimulated with 50 μM H2O2, and DJ-1 (10, 50, 100 ng/mL) to evaluate MMP-9, VEGF, TNF-α, and sRANKL production, while RANKL+ FLSs were assessed using flow cytometry. Monocytes were cultured with RANKL or IL-17A with or without DJ-1 and H2O2-pretreated RA-FLS, and tartrate-resistant acid phosphatase (TRAP) staining and RT-qPCR of osteoclast-related genes were performed. The levels of DJ-1 and H2O2 in serum and SF of RA patients were higher than those of OA patients. Under Th17-polarizing conditions, CD4+RANKL+ and CD4+CCR4+CCR6+CXCR3- T cells decreased, whereas CD4+CD25highFoxp3+ T cell increased after DJ-1 administration. Additionally, IL-17A, TNF-α, and sRANKL levels decreased in DJ-1-treated groups. DJ-1 lowered MMP-9, VEGF, TNF-α, and sRANKL levels, and RANKL+ FLS in ROS-stimulated RA-FLS. Both RANKL and IL-17A stimulated osteoclast differentiation, DJ-1 decreased TRAP+ cell count, and the expression levels of TRAP, ATP6v0d2, NFATc1, and CTSK. These findings were also observed in in vitro osteoclastogenesis with DJ-1 pretreated RA-FLS. As DJ-1 regulates Th17/Treg imbalance, pro-inflammatory cytokine production, RA-FLS activation, and osteoclastogenesis, it holds potential for RA therapy.

Characteristics, Evolution, and Formation of Cold Air Outbreaks in the Great Plains of the United States

Abstract Wintertime cold air outbreaks (CAOs) in the Great Plains of the United States have significant socioeconomic, environmental, and infrastructural impacts; the events of December 1983 and February 2021 are key examples of this. Previous studies have investigated CAOs in other parts of North America, particularly the eastern United States, but the development of CAOs in the Great Plains and their potential subseasonal-to-seasonal (S2S) predictability have yet to be assessed. This study first identifies 37 large-scale CAOs in the Great Plains between 1950 and 2021, before examining their characteristics, evolution, and driving mechanisms. These events occur under two dominant weather regimes at event onset: one set associated with anomalous ridging over Alaska and the other set associated with anomalous pan-Arctic ridging. Alaskan ridge CAOs evolve quickly (i.e., on synoptic time scales) and involve stratospheric wave reflection. Conversely, Arctic high CAOs are preceded by weak stratospheric polar vortex conditions several weeks prior to the event. Both categories of CAOs feature anomalous upward wave activity flux from Siberia, with downward wave activity flux over Canada seen only in the Alaskan ridge CAOs. The rapid development of the Alaskan ridge CAOs, also linked with a North Pacific wave train and anomalous wave activity flux from the central Pacific, suggests that these events could be forced by tropical modes of variability. These findings present evidence that different forcing mechanisms, with contrasting time scales, may produce distinct sources of predictability for these CAOs on the S2S time scale.