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Oxidized low‐density lipoprotein (oxLDL), a key component in atherosclerosis and hyperlipidemia, is a risk factor for atherothrombosis in dyslipidemia, yet its mechanism is poorly understood. In this study, we used oxLDL‐induced human aortic endothelial cells (HAECs) and high‐fat diet (HFD)‐fed mice as a hyperlipidemia model. Phosphatidylserine (PS) exposure, cytosolic Ca2+, reactive oxygen species (ROS), and lipid peroxidation were measured by flow cytometer. TMEM16F expression was detected by immunofluorescence, western blot, and reverse transcription polymerase chain reaction. Procoagulant activity (PCA) was measured by coagulation time, intrinsic/extrinsic factor Xase, and thrombin generation. We found that oxLDL‐induced PS exposure and the corresponding PCA of HAECs were increased significantly compared with control, which could be inhibited over 90% by lactadherin. Importantly, TMEM16F expression in oxLDL‐induced HAECs was upregulated by enhanced intracellular Ca2+ concentration, ROS, and lipid peroxidation, which led to PS exposure. Meanwhile, the knockdown of TMEM16F by short hairpin RNA significantly inhibited PS exposure in oxLDL‐induced HAECs. Moreover, we observed that HFD‐fed mice dramatically increased the progress of thrombus formation and accompanied upregulated TMEM16F expression by thromboelastography analysis, FeCl3‐induced carotid artery thrombosis model, and western blot. Collectively, these results demonstrate that TMEM16F‐mediated PS exposure may contribute to prothrombotic status under hyperlipidemic conditions, which may serve as a novel therapeutic target for the prevention of thrombosis in hyperlipidemia. Highlights: Oxidized low‐density lipoproteins (oxLDL) could increase phosphatidylserine (PS) exposure and procoagulant activity (PCA) of human aortic endothelial cells (HAECs) in a TMEM16F‐dependent manner.Increased intracellular Ca2+ and oxidative stress may contribute to TMEM16F‐mediated phospholipid scrambling.Hyperlipidemia exhibited a prothrombotic phenotype, which was likely related to TMEM16F‐mediated PS exposure on HAECs.Inhibition of TMEM16F or PS could be a novel therapeutic strategy to alleviate the thromboembolic complication of hyperlipidemia. [ABSTRACT FROM AUTHOR]

Earth‐abundant transition metal catalysis has emerged as an important alternative to noble transition metal catalysis in hydrogenation reactions. However, there has been no Earth‐abundant transition metal catalyzed hydrogenation of thioamides reported so far, presumably due to the poisoning of catalysts by sulfur‐containing molecules. Herein, we described the first manganese‐catalyzed hydrogenative desulfurization of thioamides to amines or imines. The key to success is the use of MnBr(CO)5 instead of commonly‐employed pincer‐manganese catalysts, together with simple NEt3 and CuBr. This protocol features excellent selectivity on sole cleavage of the C=S bond of thioamides, in contrast to the only known Ru‐catalyzed hydrogenation of thioamides, and unprecedented chemo‐selectivity tolerating vulnerable functional groups such as nitrile, ketone, aldehyde, ester, sulfone, nitro, olefin, alkyne and heterocycle, which are usually susceptible to common hydride‐type reductive protocols. [ABSTRACT FROM AUTHOR]

Earth‐abundant transition metal catalysis has emerged as an important alternative to noble transition metal catalysis in hydrogenation reactions. However, there has been no Earth‐abundant transition metal catalyzed hydrogenation of thioamides reported so far, presumably due to the poisoning of catalysts by sulfur‐containing molecules. Herein, we described the first manganese‐catalyzed hydrogenative desulfurization of thioamides to amines or imines. The key to success is the use of MnBr(CO)5 instead of commonly‐employed pincer‐manganese catalysts, together with simple NEt3 and CuBr. This protocol features excellent selectivity on sole cleavage of the C=S bond of thioamides, in contrast to the only known Ru‐catalyzed hydrogenation of thioamides, and unprecedented chemo‐selectivity tolerating vulnerable functional groups such as nitrile, ketone, aldehyde, ester, sulfone, nitro, olefin, alkyne and heterocycle, which are usually susceptible to common hydride‐type reductive protocols. [ABSTRACT FROM AUTHOR]

The link between serum uric acid (SUA) and the risk of venous thromboembolism (VTE) is well established. Recent data suggested a causative role of UA in endothelial cells (ECs) dysfunction. However, the molecular mechanism of high UA on thrombogenesis is unknown. We investigate whether high UA induce phosphatidylserine (PS) externalization and microparticle (MP) shedding in cultured EC, and contribute to UA‐induced hypercoagulable state. In the present study, we demonstrate that UA induces PS exposure and EMP release of EC in a concentration‐ and time‐dependent manner, which enhances the procoagulant activity (PCA) of EC and inhibited over 90% by lactadherin in vitro. Furthermore, hyperuricemic rat model was used to evaluate the development of thrombi following by flow stasis in the inferior vena cava (IVC). Hyperuricemia group is more likely to form large and hard thrombi compared with control. Importantly, we found that TMEM16F expression is significantly upregulated in UA‐treated EC, which is crucial for UA‐induced PS exposure and MP formation. Additionally, UA increases the generation of reactive oxygen species (ROS), lipid peroxidation, and cytosolic Ca2+ concentration in EC, which might contribute to increased TMEM16F expression. Using confocal microscopy, we also observed disruption of the actin cytoskeleton, suggesting that depolymerization of actin filaments might be required for TMEM16F activation and followed by PS exposure and membrane blebbing in UA‐treated EC. Our results demonstrate a thrombotic role of EC in hyperuricemia through TMEM16F‐mediated PS exposure and MPs release. [ABSTRACT FROM AUTHOR]

Vacuum circuit breaker is a kind of power equipment widely used in the power system. It is developing toward the direction of high voltage and high current. How to design the contact to maximize the interrupting capacity of the contact system has been conducted by scholars. In this paper, the magnetic field simulation model of contact system is established, the magnetic field distribution characteristics of vacuum interrupters are studied, and the distribution characteristics of the magnetic field in the half cycle of the cup‐shaped axial magnetic field contact system are simulated and analyzed. On this basis, by changing the contact structure parameters, the effects of the number of slots in the cup, the slot angle, the center hole of the contacts, and the length of the slots on the distribution of the axial magnetic field were obtained. The results show that grooving the contact can reduce the eddy current, but it has a limited effect on reducing residual magnetic field. The increase of slot angle of contact cup can effectively reduce the residual axial magnetic field at the zero current moment and the axial magnetic field intensity at the peak current moment. Based on the above research results, a new embedded axial magnetic contact system with 12 slots embedded magnetic ring and reverse contact cup is designed. The embedded magnetic ring and reverse spiral slot increase the axial magnetic field at the peak current moment and reduce the residual axial magnetic field at the zero current moment. Finally, the characteristics of the magnetic field have been improved significantly compared with the magnetic field of traditional cup‐shaped axial magnetic field contact. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

To reduce the size of spectral data, compressive sensing imaging systems are developed to sample fewer measurements than the Nyquist‐rate ones, from which the original data can be recovered by the optimisation model and algorithm. However, this is not a cheap option for the case where the real‐time acquisition of spectral information is required. To solve this problem, the authors propose a novel sensing approach for spectral features by combining the sampling, recovery and feature extraction. Inspired by the spectral feature representation, the sampling (sensing) matrix is designed from the training spectral samples to sense the spectral features of the imaging scene, which can be utilised for classification and recognition directly. Besides, the physical realisation of the sensing matrix for compressive spectral imaging systems is demonstrated by designing new modulation patterns of the digital micro‐mirror device. The experimental results on real spectral data show the feasibility of the proposed scheme and the robustness to the quantisation error and the measurement noise. Moreover, the proposed sensing approach can reduce the cost of computation and time greatly by removing the sparse recovery and feature extraction.. [ABSTRACT FROM AUTHOR]

Compressive sensing (CS) theory enables single‐pixel compressive imaging (SPCI) popular in optical remote sensing imaging, since single‐pixel imager not only realises the acquisition and recovery of sparse images at the sampling rates significantly below the classical Nyquist rate, but also makes use of special detectors to improve sensitivity, dynamic range, spectral range and so on. However, its requirement of static imaging condition for the time‐sequential measurements makes it difficult to apply in remote sensing, since the imaging platform is always in motion relative to the imaging scene. In this study, the authors develop a new method for SPCI on moving platform in optical remote sensing. Instead of ignoring the motion during sampling, the proposed method first builds the compressive sampling model based on motion compensation during sampling, and then reconstructs the image by frame‐by‐frame recovery method and joint recovery method, respectively, in the framework of CS theory, where the recovery condition is also analysed. To validate the basic principle and the physical feasibility of motion compensation, the authors implement the numerical simulations and optical experiments, where different conditions are exploited sufficiently. In addition, the proposed method for SPCI can be also extended into other applications, such as 360° annular imaging, multi‐pixel compressive imaging as well as super‐resolution imaging. [ABSTRACT FROM AUTHOR]

Optimization of the mechanical properties is necessary in the applications of electrospun nanofibrous matrices. In this work, mechanical reinforcement of electrospun nanofiber membranes of water-soluble polymer by the incorporation of commercial nanodiamonds (NDs) was studied. Through an ND/poly(vinyl alcohol) (ND/PVA) model system, it is demonstrated that 155% improvement of Young's modulus, 89% increase in tensile strength, and 336% elevation in energy to break are achieved by the addition of only 2 wt% ND. Fourier transform infrared spectroscopy results suggest the existence of molecular interactions between NDs and PVA matrix, which contributes to the effective load transfer from the polymer matrix to the fillers. However, higher level of ND addition (>2 wt%) aggravates the agglomeration of nanofillers in PVA matrix and offsets the reinforcing effect, as ND agglomerates may act as flaws in composite nanofibers. Furthermore, NDs have optimizing effect on the morphology of ND/PVA nanofibers through increasing the conductivity of the electrospinning solution. Therefore, ND nanofillers possess the potential to improve the mechanical performance of water-soluble polymer-based nanofiber membranes. POLYM. COMPOS., 34:1735-1744, 2013. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Gas insulated metal enclosed switchgear (GIS) has been widely used in the world because of its compact structure and adaption to the environment. However, due to frequent operation and other reasons, GIS disconnector is prone to mechanical failure with poor contact, leading to abnormal vibration signals. In this paper, a GIS disconnector contact fault simulation platform is built to collect vibration signals in three states: normal contact, moderate poor contact and severe poor contact of disconnector contact. The Ensemble Empirical Mode Decomposition (EEMD) method is used to decompose the vibration signals, and the IMF decomposition signals are screened by Kurtosis criterion (a numerical statistic method). Finally, the vibration signal features of GIS under different conditions are obtained by reconstructing the screening signals. The results indicate that, under the normal contact, the frequency of GIS vibration signal mainly presents the distribution of 100 Hz and its integer multiple frequency component, when there is a contact defect, the high frequency component in the vibration signal spectrum increases significantly, and the tripling frequency component is present, and the amplitude of component will increase with the severity of the fault. Therefore, this study provides a theoretical reference for on‐line monitoring of GIS disconnecting switch contact fault. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

We report a world record of lidar profiling of metallic Ca+ ions up to 300 km in the midlatitude nighttime ionosphere during geomagnetic quiet time. Ca+ measurements (∼80–300 km) were made over Beijing (40.42°N, 116.02°E) with an Optical‐Parametric‐Oscillator‐based lidar from March 2020 through June 2021. Main Ca+ layers (80–100 km) persist through all nights, and high‐density sporadic Ca+ layers (∼100–120 km) frequently occur in summer. Thermosphere‐ionosphere Ca+ (TICa+) layers (∼110–300 km) are likely formed via Ca+ uplifting from these sporadic layers. The lidar observations capture the complete evolution of TICa+ layers from onset to ending, revealing intriguing features. Concurrent ionosonde measurements show strong sporadic E layers developed before TICa+ and spread F onset. Neutral winds can partially account for observed vertical transport but enhanced electric fields are required to explain the results. Such lidar observations promise new insights into E‐ and F‐region coupling and plasma inhomogeneities. Plain Language Summary: Inhomogeneities (also called irregularities) in the ionospheric plasma distribution can significantly degrade satellite communications and negatively impact Global Positioning System‐based navigation systems that rely on the trans‐ionospheric radio‐wave propagation. Understanding the formation mechanisms of, thus predicting, ionospheric inhomogeneities is still a huge challenge in space weather research. Long‐lived meteoric metal ions (≫ $\gg $1 day above 100 km altitude) converge to form dense ion layers, causing plasma irregularities in the ionosphere. Therefore, it is imperative to observe and understand the transport and formation of metallic ion layers. However, it is technically challenging to detect specific ion species, especially tracing ion transport over large vertical ranges and time durations. Numerous instruments detect electron density but cannot distinguish ion species. Rocket‐borne mass spectrometers can distinguish ion species but provide only snapshots. Lidars provide a powerful tool to profile and trace metallic species over extended periods by exciting specific resonance fluorescence. The only metal ions detectable by ground‐based lidars are Ca+, and previous lidar measurements reached ∼180 km. Our Ca+ lidar upgraded with narrowband lasers has achieved high detection sensitivity, enabling the Ca+ profiling up to 300 km. Such lidar measurements of dynamical Ca+ layers open a new window to study plasma irregularities. Key Points: First lidar profiling of Ca+ ions from ∼80 to 300 km was made over Beijing in the nighttime ionosphere during geomagnetic quiet timeThermosphere‐ionosphere Ca+ layers (∼10 s cm−3) are likely formed by uplifting ions from sporadic Ca+ at ∼110 km & show complex structuresSpread F occurs concurrently with Thermosphere‐ionosphere Ca+ & strong sporadic E layers occur before the onset of TICa+ and spread F, suggesting E‐ and F‐region coupling [ABSTRACT FROM AUTHOR]