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In this article, we introduce a new command, classifylasso, that implements the classifier-lasso method (Su, Shi, and Phillips, 2016, Econometrica 84: 2215–2264) to simultaneously identify and estimate unobserved parameter heterogeneity in panel-data models using penalized techniques. We document the functionality of this command, including 1) penalized least-squares estimation of group-specific coefficients and classification of unknown group membership under a certain number of groups; 2) two lasso-type estimators with robust standard errors, namely, classifier-lasso and postlasso; and 3) determination of the number of groups based on an information criterion. We further develop some postestimation commands to display and visualize the estimation results. [ABSTRACT FROM AUTHOR]

Direct power control (DPC) has gained increasing attention in recent years as a simple and efficient control strategy for pulse width modulation (PWM) rectifiers. In this paper, the idea of DPC is introduced into the three-phase coupled inductor-based bipolar-output active rectifier (TCIBAR) for the first time, and a virtual vector-based direct power control (VVB-DPC) strategy is proposed for TCIBAR to realize the bipolar DC power supply for more electric aircraft (MEA). First, the mathematical model of the TCIBAR is deduced, and the basic principle of the classic DPC strategy is reviewed. On this basis, the limitations of the classic DPC strategy in TCIBAR control are analyzed. Second, a set of virtual vectors are derived to establish a novel virtual-vector switching table. Based on the virtual-vector switching table, the hysteresis power control of TCIBAR can be realized without affecting the DC-side neutral-point potential of TCIBAR. Finally, a neutral-point potential control method based on DPC architecture is studied and integrated into the VVB-DPC strategy to maintain the bipolar DC voltage balance of TCIBAR under unbalanced load conditions. The VVB-DPC strategy is experimentally studied on a TCIBAR prototype, and the experimental results verify the feasibility and effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

A low switching frequency of power converter is mandatory in high-power motor drives to suppress the switching loss and thermal stress. In this case, the asynchronous modulation may incorporate abundant harmonics. The well-known approach to solve the problem is to adopt the synchronous modulation. Among existing techniques, synchronous space vector modulation (SSVM) owns the simpler implementation. However, it is a big challenge to establish a closed-loop scheme based on SSVM. Therefore, this manuscript proposes the flux trajectory tracking based implementation of SSVM for induction motors. A state observer is first built up in a hybrid reference frame to acquire the stator flux with a long sampling period. Then, the stator flux is enforced to move on a predefined trajectory with an adjustable rotation speed. As a result, synchronizations and symmetries of voltage pulses, smooth transitions between different pulse patterns and fast dynamic response can be achieved without complex compensations and extraction of fundamental signals. Both simulations and experiments verify the effectiveness of proposed method. Particularly, the current harmonics are effectively suppressed compared with traditional method with asynchronous modulation. [ABSTRACT FROM AUTHOR]

The dual-stator winding induction generator (DWIG) is an alternative main generator in a variable frequency ac power system. So far, the existing studies have not covered the issue of DWIGs excitation controllability, which is a matter of importance for airworthiness. In this article, we develop an impedance-based modeling and analysis technique to investigate DWIGs excitation controllability. Two related topics are presented: the spontaneous self-excitation analysis in uncontrolled system and the implicit internal self-excitation pattern analysis in actively controlled system. In the topic about spontaneous self-excitation, a virtual impulse source technique is developed to derive the impedance-based method properly in the analysis for uncontrolled DWIG. In the second topic, the analysis performed in the presence of a closed-loop controller figures out the same underlying mechanism in both the plant's open-loop stability and the spontaneous self-excitation. The experimental results verify the proposed analysis and techniques that benefit the comprehensive understanding and practical application of DWIG-based power system. [ABSTRACT FROM AUTHOR]

A novel 24/17-pole 3-phase stator wound field flux switching (SWFFS) machine with the combination of overlapping armature winding (OAW) and asymmetric stator poles (ASP) is proposed for higher torque density in this article. First, the air-gap modulation principle of the 24/17-pole OAW-SWFFS machine is analyzed to better understand its torque production mechanism. Second, since the torque capacity will be greatly restricted by the serious magnetic saturation which is introduced by the OAW configuration, two effective measures are proposed from two perspectives in this article to solve this problem. The first measure is to reduce the magnetic saturation directly by optimizing the area ratio of armature slot and excitation slot, and thus, the torque density can be improved effectively. The second measure is to further enhance the open circuit flux linkages, back electromotive force (EMF), and thus, the torque density by adopting the proposed ASP structure. Furthermore, the accurate ASP distances which are corresponding to the largest back EMF can be obtained effectively based on the air-gap field modulation theory. Finally, the proposed design is validated experimentally by a prototype machine. The simulated and experimental results show that about 25.7% higher torque density can be obtained when compared with 24/14-pole SWFFS machine. [ABSTRACT FROM AUTHOR]

Active disturbance rejection control using extended state observer (ESO) is less dependent on the knowledge of the system. It has proved to be an excellent scheme for speed control of electrical drives. However, for time-varying disturbance, the observation precision of conventional ESO is undesired, which limits the speed tracking accuracy. Accordingly, this article proposes an enhanced speed controller for electrical drives based on adaptive switching high-order ESO (ASHESO). First, the critical parameters affecting the steady-state performance of ASHESO are determined according to frequency analytical results. Then, optimized observer gain is obtained by modifying a part of pole locations, which weakens the influence of noise on estimated state. Finally, an adaptive switching gain mechanism is proposed according to the closed-loop tracking error and the swiftness of dynamic response is maintained. The proposed speed controller has achieved high estimation accuracy for disturbance and strong immunity to measurement noise. The feasibility and effectiveness of the strategy is verified on a laboratory permanent magnet synchronous motor (PMSM) drive system. [ABSTRACT FROM AUTHOR]

The popularity of electric vehicles (EVs) brings environmental benefits, but their hard-to-estimate stochastic charging behaviors places additional diversity on grid load management. This paper proposes a procedure to identify typical charging load profiles (CLPs) via large scale charging session data from charging stations (CSs). The daily CLPs are computed from charging sessions, and a comprehensive similarity metric based on the weighting of Euclidean and Pearson correlation coefficient is proposed to achieve better clustering. The clustering is performed using the Clustering LARge Applications (CLARA) algorithm to accommodate large sample scenarios. Subsequently, hierarchical clustering of CSs is performed based on possible CLPs，and their CLPs are estimated by Monte Carlo simulation. The performance of the proposed method is tested and evaluated with over 340,000 charging sessions from 109 CSs in Wuhan at central China, and seasonal differences in CLPs are explored. The results show that the method of mining typical CLPs from charging sessions is effective, 17 typical CLPs are identified in different seasons, which provide effective information on the fluctuation and magnitude of daily power demand, the charging power demand also shows significant seasonal differences, and good accuracy is achieved by dividing the CSs into different groups for load estimation. • A method for identifying typical charging load profiles from charging session data is proposed. • 17 typical charging load profiles for charging stations in Wuhan are reported. • Monte Carlo simulation combined with typical charging load profiles enables good estimation of charging loads. • Seasonal differences in charging loads are compared. [ABSTRACT FROM AUTHOR]

A swirling flow tundish is developed to deeply clean the liquid steel through enhancing the coalescence of inclusions. The swirling flow is generated using the gravitational energy of liquid steel, without any external energy. Inclusions will gather to the center of the swirling flow by centripetal force, due to the density difference between inclusions and liquid steel. Thus, small inclusions can coalesce into larger ones, and then float to the top surface by their self‐buoyance. Physical experiments are carried out in a 1/2.5 scale five‐strand tundish, to investigate flow characteristics in the swirling flow tundish, compared with that in the tundish with a conventional turbulent inhibitor. Numerical modeling is developed to evaluate the swirling strength of liquid flow in swirling chambers in different sizes, which is related to the effect of inclusion coalescence. The results reveal that swirling chamber in diameter of 700 mm produces the highest swirling flow strength. The swirling system can not only improve the flow field, with a 21.75% reduction of dead volume, but also uniform flow characteristics at each strand. In addition, the swirling chamber inhibits the normal impact of the reversed flow on tundish surface, which is beneficial for remaining a stable slag layer. [ABSTRACT FROM AUTHOR]

Normal pregnancy is essential for human reproduction. However, BaP (benzo(a)pyrene) and its metabolite BPDE (benzo(a)pyrene‐7,8‐dihydrodiol‐9,10‐epoxide) could cause dysfunctions of human trophoblast cells and might further induce miscarriage. Yet, the underlying mechanisms remain largely unknown. Herein, we identified a novel upregulated lnc‐HZ04 and a novel downregulated miR‐hz04 in villous tissues of unexplained recurrent miscarriage (RM) relative to those in healthy control tissues and also in BPDE‐treated human trophoblast cells. Lnc‐HZ04 directly and specifically bound with miR‐hz04, diminished the reduction effects of miR‐hz04 on IP3R1 mRNA expression level and on IP3R1 mRNA stability, and then activated the Ca2+‐mediated IP3R1/p‐CaMKII/SGCB pathway, which further promoted trophoblast cell apoptosis. The miR‐hz04 target site on lnc‐HZ04 played crucial roles in these regulations. In normal trophoblast, relatively less lnc‐HZ04 and more miR‐hz04 suppressed this apoptosis pathway and gave normal pregnancy. After exposure to BPDE or in RM tissues, p53 was upregulated, which might promote p53‐mediated lnc‐HZ04 transcription. Relatively more lnc‐HZ04 and less miR‐hz04 activated this apoptosis pathway and might further induce miscarriage. BaP could also induce mice miscarriage by upregulating its corresponding murine apoptosis pathway. Therefore, BPDE‐induced apoptosis of human trophoblast cells was associated with the occurrence of miscarriage. This work discovered the regulation roles of lnc‐HZ04 and miR‐hz04 and provided scientific and clinical understanding of the occurrence of unexplained miscarriage. [ABSTRACT FROM AUTHOR]

The general rules of rotor pole and armature winding configurations combinations for 24-slot stator wound field flux switching machines (SWFFSMs) are investigated thoroughly in this article. Meanwhile, based on the virtual coil method, a novel general auxiliary evaluation variable, which is proportional to the fundamental amplitude of open-circuit flux-linkage of armature coil is proposed in this article. Hence, these SWFFSMs with larger open-circuit flux-linkage and back-EMF can be obtained effectively. In addition, the effect of rotor poles on the complementarity of armature windings is analyzed so that more sinusoidal and symmetrical back-EMF can be acquired. Furthermore, for these SWFFSMs with larger open-circuit back-EMF, the torque capability is restricted to a considerable extent due to the deep magnetic saturation caused by overlapping armature winding. Hence, a new method by optimizing the ratio of armature slot area and excitation slot area is proposed in this article to ensure that the higher torque density of selected SWFFSMs can be maintained. To verify the validity of analysis and methodology proposed in this article, seven representative SWFFSMs are chosen for verification at no load by the finite-element analysis (FEA) while a 24s/17p SWFFSM with the highest torque density is chosen for further verification at on-load conditions by the FEA and experiments. [ABSTRACT FROM AUTHOR]

In this article, we present a closed-loop dynamic control scheme for a dual-stator winding induction generator (DWIG) with selective harmonic elimination pulsewidth modulation (SHEPWM). This control scheme can be applied in a variable-frequency ac power system based on the DWIG, which is able to operate in low-carrier-ratio conditions, especially in high-power aeroapplications. Common closed-loop induction machine control schemes, such as vector control strategy, generally lead to control failure with SHEPWM implemented. This proposed closed-loop dynamic control scheme makes the dynamic operation of the DWIG power system feasible with SHEPWM. The scheme consists of three main parts: the complex-signal observer for DWIG, outer loop controller for DWIG, and stator flux-linkage trajectory tracking controller. The complex-signal observer provides the extra steady-state components of control signals by using the complex coefficient filter. The outer loop controller provides the dynamic commands for control signals. Finally, the flux-linkage trajectory tracking control (FTTC) synthesizes these signals and serves as the inner loop. The simulation and experimental results verify the validity and effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

The moving-coil type voice coil motor (VCM) has very light moving mass, which can achieve higher reciprocating frequency and work efficiency. However, the power supply lead connected to the moving coil can be easily broken under long-term reciprocating motion, so it is rarely used in compressor drive systems. The core technology of the compressor development trend is a driving motor with high-efficiency, high reciprocating frequency, certain piston stroke, and light moving mass. Due to its structural characteristics, the moving-coil type VCM has broad application prospects. This article proposes a new structure for power supply of a moving coil VCM based on the principle of electromagnetic induction. The proposed VCM can overcome the problems of aging and disconnection of power supply lines caused by reciprocating motion, and meet the requirements of high-frequency and long-term repetitive action of the moving coil. The content of this article is as follows. First, the construction of the proposed VCM is introduced. Second, the power-driven circuit based on interleaving double switch forward converter is provided. Finally, two working modes of drive circuit for reciprocating motion are proposed. Simulation and experimental results verify the effectiveness of the method. [ABSTRACT FROM AUTHOR]

The traditional direct toque control (TDTC) for induction motors (IM) is afflicted by large torque ripple, high current total harmonic distortion (THD), and variable switching frequency. Recently, some improved direct torque control (DTC) methods have been proposed to address the above problems, but they often suffer from obscure concept, intensive computation, and poor robustness. To further improve the performance, this article proposes a DTC method based on minimum voltage vector (VV) error. The proposed strategy effectively optimizes the duty ratio of fundamental VV to minimize the error between reference VV and final VV imposed on motor terminals. The optimization algorithm dose not increase the system's complexity much and can be intuitively understood by a graphical interpretation. Experiment comparisons between the proposed strategy and some existing DTC methods are conducted on a 0.55-kW IM platform. The proposed DTC method has proven to achieve better steady-state performance, while retaining fast dynamic response of TDTC. Furthermore, the proposed method can obtain almost constant average switching frequency in the entire speed range, especially with rated load, due to the utilization of proportional-integral type torque regulator. [ABSTRACT FROM AUTHOR]

In this article, we present a dual-stator structure-parallel fault-tolerant machine (DSSPFTM). In this machine, the radial-flux dual-stator structure with a higher density is adopted to the fault-tolerant system. For better performance in fault condition, the combination of permanent-magnet component (PMC) and reluctance component (RC) in the rotor and large-opening slot is proposed. Because of the same poles and torque-variation principle, the PMC and RC are combined. The PMC is devised to supply most of the torque in normal conditions, while the RC provides enough self-inductance for limiting current under short-circuit (SC) occasion. Most of the flux leakage is separated from the active flux and the overload ability is improved. The design process of DSSPFTM is described in steps and details. Based on the fundamental of maximum torque under normal conditions, PMC and RC are integrated together. The end flux leakage originating from the adjacency of RC to PMC and the effect of RC length on torque are analyzed. The back-EMF, torque, inductance, loss, efficiency, and SC analysis are demonstrated. The stress and deformation distribution of the rotor and the comparison with the traditional structure are conducted. A prototype DSSPFTM is designed and manufactured. The experiments accord with simulations, indicating that the DSSPFTM with fault tolerance can improve the torque density effectively. [ABSTRACT FROM AUTHOR]

To elude from the camera, suspects often hide behind other things or persons, leading to a series of occlusion patterns. These suspects are notoriously hard to search due to the substantially various appearance in the intricate occlusion patterns. Existing methods solving occlusion problem depend on learning several frequent patterns separately. It brings not only high consumption but also less coverage of patterns in real application scenarios. Different from the current researches which only concern certain patterns that do not synthesize the occlusion patterns in practical applications, we consider a wide range of occlusion patterns which conform the real application scenarios in one coherent model with less interference of both the occlusion and background areas and without redundant computation. Consequently, we propose a channel-guided mechanism (CGM) for occluded suspect search in this paper. The core idea is that different body areas have been activated via different channels in convolutional neural networks. By suppressing the effects of the interference areas, such as occlusion and background areas, we can filter out the visible areas which are the essential elements for the occlusion patterns. Channel-aware attention is introduced to learn the relation between areas and channels. Furthermore, we can identify suspects using a rule which focuses more on the visible area and focuses less on the occluded area in the specific occlusion pattern. Extensive evaluations on two challenging datasets confirm the effectiveness of the proposed CGM. [ABSTRACT FROM AUTHOR]

This article presents the optimal design of a dual-stator permanent magnet fault-tolerant machine (DSPMFTM). In order to enhance the torque density, the radial-flux dual-stator structure is expanded to redundant situation. The parallel rotor is proposed to add self-inductance for realizing limited short-circuit current, and thus, the deep and narrow notches (DNNs) are replaced with large-opening slots. The optimal design of DSPMFTM is raised in this article because of the more complexity of flux coming from the short distance between the reluctance part (RP) and the permanent magnet part (PMP). The influences of slot opening, separating distance between PMP and RP along with permanent-magnet shape, are considered. Also, the varieties of torque density, ratio of mutual inductance to self-inductance, and short-circuit current to rated value are examined. A prototype is designed and manufactured according to the optimization results. The experimental results are coincident with the simulations, indicating that the DSPMFTM has a better performance in torque density and fault tolerance. [ABSTRACT FROM AUTHOR]

Vision-based behavior recognition is the analysis and recognition of human behavior in video. It has been widely used in many aspects such as multimedia information retrieval, behavior monitoring, and robot perception. This paper uses the Independent Subspace Analysis (ISA) deep network model feature extraction method, which is based on the ISA model and neural network theory, and combines data preprocessing methods, K -means clustering methods, and Support Vector Machine (SVM) classifiers to achieve video classification and identification of human behavior. The ISA-based deep network model feature extraction method is an unsupervised learning method that can obtain behavior characteristics with good invariance and characterization capabilities in video human behavior. The experiment was conducted on the basis of the Hollywood2 human behavior data set. This experiment was compared with other commonly used human behavior feature extraction and recognition methods. The experimental results validated the effectiveness and advantages of this method in the classification and recognition of human behavior. [ABSTRACT FROM AUTHOR]

Rational design of high-efficiency heterostructure photocatalyst is an effective strategy to realize photocatalytic H 2 evolution from pure water, but remains still a considerable challenge. Herein, an anatase/rutile TiO 2 /g-C 3 N 4 (A/R/CN) multi-heterostructure photocatalyst was prepared by a facile thermoset hybrid method. The combination of two type-II semiconductor heterostructures (i.e., A/R and R/CN) significantly improve the separation and transfer efficiency of photogenerated carriers of anatase TiO 2 , rutile TiO 2 and g-C 3 N 4 , and A/R/CN photocatalyst with high activity is obtained. The optimal A/R/CN photocatalyst exhibits significantly increased photocatalytic overall water splitting activity with a rate of H 2 evolution of 374.2 μmol g−1h−1, which is about 8 and 4 times that of pure g-C 3 N 4 and P25. Moreover, it is demonstrated to be stable and retained a high activity (ca. 91.2%) after the fourth recycling experiment. This work comes up with an innovative perspective on the construction of multi-heterostructure interfaces to improve the overall photocatalytic water splitting performance. Image 1 • Anatase/rutile TiO 2 /g-C 3 N 4 (A/R/CN) multi-heterostructure was prepared. • The heterostructure can effectively separate and transfer photogenerated carriers. • The A/R/CN hybrids exhibite efficient photocatalytic overall water splitting. • The A/R/CN shows excellent stability and reusability. [ABSTRACT FROM AUTHOR]

Owing to simple implementation and excellent performance, the conventional stator flux observer based on active flux concept is considered as a competitive scheme for direct torque control system of a permanent magnet synchronous motor. However, it is constructed by a large number of motor parameters, which may vary with the operating points. This leads to weak robustness. To improve its performance, a stator flux observer with phase self-tuning is proposed as an improved version in this article. First, relationship between the stator flux observed values obtained by current and voltage models and observed error of rotor position angle is analyzed. Then, according to the aforementioned analysis, a phase self-tuning link constructed by a proportional-integral regulator is proposed to ensure that the observed coordinate system converges to the actual one even under motor parameters vary conditions. Consequently, the robustness and accuracy of the stator flux observer can be improved. Finally, the stability of the proposed phase self-tuning link is analyzed. Experimental comparison between the conventional stator flux observer based on active flux concept and the proposed improved stator flux observer has been done, and the results verify the feasibility and effectiveness of the proposed stator flux observer. [ABSTRACT FROM AUTHOR]

Micro-bubbles were generated using gas injection through tiny orifices located at the upper part of the ladle shroud, for deep cleaning the liquid steel. An impact pad was employed to improve the dispersion of micro-bubbles in the liquid bath, reduce the collision between bubbles, as well as to achieve the conventional functions of a turbulent inhibitor. A 3-D numerical modeling was developed to predict the flow characteristics and bubble motion behaviors under the effect of the impact pad, with the bubble sizes obtained from the measurements in full-scale water experiments. For comparison, the corresponding numerical simulation was also carried out in the tundish with a conventional turbulent inhibitor. It was found that the impact pad promotes the spreading of micro-bubbles in the tundish bath, which could effectively reduce the coalescence of bubbles, so as to restrain the secondary bubble grow-up. The global efficiency of inclusion removal by bubble flotation was evaluated, considering the mechanism of repeated bubble sweeps in each element. The inclusion removal was raised by 14.33–37.09% due to the extended area of bubbles dispersion, even with the same bubble amount and size. Unlabelled Image • An impact pad can promote bubble dispersions and inhibit the entry flow turbulence. • Bubble coalescence was studied based on different distributions of bubbles. • Inclusion removal was evaluated, considering the effect of repeated bubble sweeps. [ABSTRACT FROM AUTHOR]

Direct torque control (DTC) has become a widely acceptable alternative to field-oriented control in permanent magnet synchronous motor (PMSM) drives. Deadbeat direct torque and flux control (DB-DTFC) is a significant improvement over the classical DTC. However, there are some aspects that can be improved, such as insufficiently small electromagnetic torque ripple, unsmooth dynamic response, heavy computation burden, and relatively weak robustness to motor parameters variation. To improve the operation performance, an advanced DB-DTFC strategy is proposed in this article. First, the algorithm model based on stator flux oriented coordinate system is deduced. On this basis, the basic principle of proposed DB-DTFC is presented. Second, a novel graphical analysis method is proposed to help illustrate the proposed strategy. Third, a general solution method is proposed to solve the reference stator voltage, which is a key variable for the DB-DTFC. Finally, the stability of system is analyzed. Theoretical and experimental comparisons between the proposed DB-DTFC and the conventional DB-DTFC are done. The results show that the performance in the aspects of electromagnetic torque and stator current ripples reduction, dynamic response, computation burden, and robustness to motor parameters variation are all improved in the proposed DB-DTFC. [ABSTRACT FROM AUTHOR]

This article introduces the classical direct torque control (DTC) to a three-phase open-end winding permanent magnet synchronous motor with common dc bus for the first time. The electromagnetic torque and the stator flux are controlled at the same time. However, the zero-sequence current is not suppressed, and the ripples of the electromagnetic torque and stator flux are large. To improve the operation performance of this drive system, a DTC based on a duty ratio modulation (DRM-DTC) is proposed. First, a deadbeat zero-sequence current controller is proposed in the DRM-DTC to suppress the zero-sequence current. Second, another strategy, which is based on a graphical analysis method and a simple deadbeat direct torque and flux controller, is proposed to optimize the duty ratio of the active voltage vector. Thus, the electromagnetic torque and stator flux ripples can be reduced. Finally, an optimized pulsewidth modulation implementation strategy is proposed in the DRM-DTC to further reduce the switching frequency of inverters. The classical DTC and the proposed DRM-DTC are compared through simulation and experiment, and the results verify the effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanotubes (SWNTs), especially their semiconducting type, are promising thermoelectric (TE) materials due to their high Seebeck coefficient. In this study, the in-plane Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ) of sorted semiconducting SWNT (s-SWNT) free-standing sheets with different s-SWNT purities are measured to determine the figure of merit ZT. We find that the ZT value of the sheets increases with increasing s-SWNT purity, mainly due to an increase in Seebeck coefficient while the thermal conductivity remaining constant, which experimentally proved the superiority of the high purity s-SWNT as TE materials for the first time. In addition, from the comparison between sorted and unsorted SWNT sheets, it is recognized that the difference of ZT between unsorted SWNT and high-purity s-SWNT sheet is not remarkable, which suggests the control of carrier density is necessary to further clarify the superiority of SWNT sorting for TE applications. [ABSTRACT FROM AUTHOR]

A position sensor is usually required in the existing fault‐tolerant direct torque control (FT‐DTC) system for the multiphase permanent magnet synchronous motor (PMSM). Thus, the volume, weight, and cost of the system is increased, and the reliability is decreased. The conventional high‐performance position sensorless strategies for the multiphase motor under fault‐free condition cannot be directly applied to FT‐DTC system. To improve this situation, a high‐speed position sensorless FT‐DTC strategy for a six‐phase symmetrical winding PMSM with two opened phases is proposed in this study. Firstly, modified variables and a new rotating coordinate system are defined to achieve the symmetrical and decoupled mathematical model. Secondly, a stator flux observer based on the modified variables and a new coordinate system is proposed. According to the current model of modified stator flux, the estimated modified stator current can be achieved. Then, the estimated error of the modified stator current is sent to the integrator of the modified stator flux observer to correct the voltage model. Finally, the proposed stator flux observer is applied in FT‐DTC for six‐phase PMSM with two opened phases to realize the position sensorless operation at high speed. The experimental results verify the feasibility and effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

A smart power flow node (SPFN) aimed at a hybrid ac/dc electric power system (EPS) for future more electric aircraft is presented. The SPFN is researched to enhance the performance of the EPS. Based on the SPFN, new power flow paths are established for the EPS, and intelligent power flow management of the EPS is realised. A multi‐port topology is designed for the SPFN to be compatible with different ac and dc power ports. Moreover, three operating modes of the SPFN are studied to realise uninterrupted power supply, power support of high‐power load and power transfer of the feedback energy from regenerative load. The experimental results verify the feasibility and availability of the SPFN and show that the SPFN can improve the equivalent capacity as well as the power supply reliability of the EPS. [ABSTRACT FROM AUTHOR]

Abstract The stability of Ag-based photocatalysts restricted their photocatalytic performance because of their photocorrosion. To solve the problem, the g-C 3 N 4 /Ag 3 PO 4 was fabricated through a calcination-deposition way and the novel g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 catalytic system was constructed in the article. The cyclic experiment and X-ray diffraction peaks of Ag 3 PO 4 and Ag 3 PO 4 -H 2 O 2 showed that the structure stability of g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 was protected by using H 2 O 2 preventing the photoetching of Ag 3 PO 4. Ultraviolet visible diffuse reflectance spectroscopy declared that the construction of g-C 3 N 4 /Ag 3 PO 4 heterojunction greatly improved the utilization of visible light. In addition, the transient photocurrent responses and photoluminescence spectra demonstrated that the photoinduced holes and electrons were separated effectively formed by g-C 3 N 4 and Ag 3 PO 4. Obviously, the above three processes promoted the excellent stability and photocatalytic performance of the g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 catalytic system. The free radical trapping experiments also proved that holes played a leading role in photocatalytic degradation, and the possible mechanism of the g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 catalytic system was proposed. Graphical abstract Image 1 Highlights • g-C 3 N 4 /Ag 3 PO 4 heterojunction was fabricated via a calcination-deposition method. • The stability of Ag 3 PO 4 was greatly improved after adding H 2 O 2. • The photogenerated charge of g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 was effectively separated. • The degradation performance of g-C 3 N 4 /Ag 3 PO 4 -H 2 O 2 was boosted by synergistic effect. • The possible routes of charge carrier transfer and separation were described. [ABSTRACT FROM AUTHOR]

Owing to high driving power, good controllability, and strong fault-tolerant ability, a three-phase open-end winding permanent magnet synchronous motor driven by a dual inverter with common dc bus is considered as a competitive solution. However, a path for zero-sequence current is provided in this drive topology. Thus, the system loss would be increased, and the maximum output power is limited. In order to suppress the zero-sequence current, a novel space vector pulsewidth modulation (SVPWM) strategy based on the hysteresis controller of zero-sequence current is proposed in this paper. The voltage vectors, whose polarity of zero-sequence voltages (ZSVs) is opposite with the polarity of zero-sequence current, are selected as the basic voltage vectors of SVPWM for fundamental plane. Meanwhile, the linear modulation range is analyzed. According to the analysis results, the proposed strategy has the advantage of wide linear modulation range of ZSV under the condition of high fundamental modulation ratio. The experimental results show that the zero-sequence current is effectively suppressed by the proposed modulation strategy. Furthermore, the comparative evaluation of the proposed modulation strategy, the conventional SVPWM, the SVPWM with zero ZSVs, and the zero vector redistribution SVPWM with zero-sequence current proportional-resonant controller is conducted to demonstrate the superiority of the proposed strategy. [ABSTRACT FROM AUTHOR]

Highlights • Applied an extra current excitation to reduce polarization voltage. • Analyzed parametric sensitivity of current excitation to model parameters. • Developed a method to determine the parameters for the current excitation. • Shortened the test time due to the active polarization voltage reduction. • Validated the feasibility and superiority with experiments. Abstract The correlation between state of charge (SoC) and open-circuit voltage (OCV) is a crucial characteristic parameter in many aspects of the battery management system (BMS). However, it is a challenging task to obtain the accurate SoC-OCV correlation with a high test efficiency. In this paper, an improved OCV characterization test is proposed to actively reduce the polarization voltage. Based on the third-order equivalent circuit model (ECM), two sets of current pulses are applied to accelerate the convergence of the battery terminal voltage, thus the test time is effectively shortened compared to the conventional incremental OCV characterization test. Furthermore, the parametric sensitivity of the imposed current excitation to battery model parameters is analyzed. Subsequently, the parametric determination method for the imposed current excitation is provided. Experiments are conducted on a lithium-ion polymer battery to prove the feasibility of the proposed test procedure. Comparison with the conventional OCV characterization test further demonstrated the superiority of the proposed test procedure. [ABSTRACT FROM AUTHOR]

Dual stator-winding induction generator (DWIG) is attractive in stand-alone power systems, and the aim of this paper is to develop the dc generating system of five-phase DWIG with an open phase. First, the relationship between flux and torque is constructed based on the reduced-order transformation, modified flux, and current. Second, the relation between modified voltage and current on the dq plane is constructed. The current of fundamental plane is used for the control loop of the power-winding voltage and control-winding voltage, respectively. Third, the current of the modified secondary subspace plane is used to control the five-phase DWIG operation at minimum control-winding loss. Finally, the simulation and experimental results are given to verify that the amplitude of phase current and output voltage can be regulated effectively by the proposed control strategy. [ABSTRACT FROM AUTHOR]

This study proposes a novel dual stator composite rotor axial flux induction motor (DSCRAFIM) whose solid rotor is coated with copper layers. A novel multi‐slice and multi‐layer method is developed and applied to analyse the three‐dimensional electromagnetic field distribution in DSCRAFIM. In the application of this analytical method, DSCRAFIM is equivalent to a finite set of equal‐width and increasing‐length double primary composite secondary linear induction motors, whose steel secondary is divided into a finite set of equal‐height layers. The surface impedance theory is applied to derive the improved equivalent circuit model (IECM) of DSCRAFIM, which considers the coupling relationship between dual stator windings. The accuracy of this IECM is then verified by both finite‐element analysis and experimental test. [ABSTRACT FROM AUTHOR]

As artificial extracellular matrix-like materials, silk-elastin-like protein (SELP) hydrogels, with excellent mechanical properties, high tunability, favorable biocompatibility, and controlled degradability, have become an important candidate in biomedical materials. In this study, SELP is composed of silk-like (GAGAGS) and elastin-like (GXGVP) tandem repeats, in which X residues are set as tyrosine and lysine. Furthermore, SELP polymers are prepared via SpyTag/SpyCatcher. To explore a gentler and more efficient enzymatic crosslinking method, an innovative method was invented to apply laccase to catalyze the formation of SELP hydrogels. Gelation could be successfully achieved in 2–5 min. SELP hydrogels mediated by laccase had the characteristic of low swelling rate, which could maintain a relatively stable shape even when immersed in water, and hence had the potential to be further developed into injectable biomaterials. Additionally, SELP hydrogels cross-linked by laccase showed excellent biocompatibility verified by L929 and HEK 293 T cells with cell viability >93.8 %. SELP hydrogels also exhibit good properties in sustained drug release and cell encapsulation in vitro. This study demonstrates a novel method to construct SELP hydrogels with excellent biocompatibility and expands the possibility of SELP-based material applications in biomedical fields. [Display omitted] • Ultra-high molecular weight (UHMW) silk-elastin-like protein (SELP) was obtained by protein polymerization mediated by SpyTag/SpyCatcher. • As a novel green catalyst, laccase could catalyze the formation of SELP hydrogels in 2–5 min. • SELP hydrogels formed by laccase-mediated reactions demonstrated good cytocompatibility and exhibited good swelling properties. • Laccase-mediated SELP hydrogels showed excellent performance in cell encapsulation and sustained drug release. [ABSTRACT FROM AUTHOR]

In the solar reflective band, an on-board calibration method based on a solar diffuser (SD) can realize full aperture, full field of view, and end-to-end absolute radiometric calibration of optical remote sensors. The SD's bidirectional reflectance distribution function (BRDF) is a key parameter that affects the accuracy of the on-board calibration. High-accuracy measurement of the SD BRDF is required in the laboratory before launch. Due to the uncertainty of the goniometer system, polarization effects, and other factors, the measurement uncertainty of the SD BRDF at large incident angles is much higher than that at a 0° incident zenith angle and 45° reflection zenith angle. In this paper, an absolute BRDF measurement facility is reported. The goniometric system consists of a high-brightness integrating sphere as a radiation source, a six-axis robot arm, and a large rotation stage. The measurement wavelength range was from 350 nm to 2400 nm. An improved data processing method based on the reciprocity theorem was proposed to reduce the measurement uncertainty of the SD BRDF at large incident angles. At an incident zenith angle of 75°, the improved data processing method reduced the measurement uncertainty of the SD BRDF by 52% at 410 nm to 480 nm, by 70% at 480 nm to 1000 nm, and by 20% at other bands compared to the absolute measurement method. The influence of the radiation source, goniometer system, detection system, and other factors on the measurement uncertainty are analyzed in this paper. The results show that the measurement uncertainty (coverage factor k = 2) of the SD BRDF was better than 1.04% at 350 nm to 410 nm, 0.60% at 410 nm to 480 nm, 0.43% at 480 nm to 1000 nm, and 0.86% at 1000 nm to 2400 nm. [ABSTRACT FROM AUTHOR]

To improve the power factor and reliability for medium/high-power supply, a three-phase single-stage ac–dc converter based on magnetic-combination transformer with power factor correction (PFC) function is presented in this paper. According to the three-phase instantaneous power balance principle and the concept of the magnetic-flux superposition, a novel magnetic-combination transformer is proposed, which can make three-phase symmetrically and sinusoidally fluctuant power add to be constant. Therefore, the induced voltage of the secondary winding is constant. To realize sinusoidally fluctuant power in the input stage, dc-link filter capacitance can be reduced to a several-microfarad level. Single-stage PFC function, no electrolytic capacitor, and constant output voltage can be realized in the converter. The principle and the structure of the novel magnetic-combination transformer are analyzed in detail in this paper. Simulation and experimental results are presented to verify the feasibility of the proposed converter. [ABSTRACT FROM AUTHOR]

This paper presents a single-phase to three-phase adjustable-speed drive (ASD) system, which consists of a diode rectifier and a single-stage boost inverter without electrolytic capacitors (E-caps). The system has no shoot-through issues and gains high reliability due to the shoot-through zero-state regulation method. By using electrolytic capacitors-less topology, the lifetime can be greatly increased. By properly designing the tapping position of the inductor, the system has a high boost-inversion gain and can ride through grid voltage sags. By using the proposed harmonic injection method, the system can realize high input power factor and small dc-link ripple voltage, simultaneously. Experimental results of the electrolytic capacitors-less single-stage boost inverter (E-caps-less SSBI) based single-phase to three-phase ASD system are obtained to verify the actual performances. [ABSTRACT FROM AUTHOR]

To improve reliability and realize electric isolation, an integrated topology of the charger and drive for medium/high-power electric buses is presented in this paper. The proposed integrated topology can solve the voltage matching problem between the power grid and the battery voltage and between the battery voltage and the drive system. The integration can be realized by using the common hardware of the charging system and the drive system, which can reduce the cost and weight of the whole system. To improve the power level, a three-phase combined full-bridge converter based on the magnetic-combination transformer is adopted in the charging system, which has a single-stage power-factor-correction function, electric isolation, and no electrolytic capacitor. To better reflect the integration, the motor drive system adopts a single-stage boost dual-inverter that is the reconfiguration of the magnetic-combination transformer and the 3-H bridge converter in the charging system and few extra components. The drive system has a single-stage boost/buck function, high reliability, and strong fault-tolerant ability. The proposed integrated topology, which can realize a charging function and a driving function, has been analyzed in this paper. Finally, the experimental results verify the feasibility of the integrated topology. [ABSTRACT FROM PUBLISHER]

In this paper, a new electric drive system based on a six-phase ten-pole dual-winding fault-tolerant permanent-magnet (DFPM) motor for aerospace applications is proposed and investigated. The proposed DFPM motor consists of optimal surface-mounted permanent-magnet (PM) rotor and 12-slot stator with two sets of independent three-phase concentrated armature windings on alternate teeth, which incorporates the merits of high power density and high efficiency of the PM motor and high fault tolerance of the dual-winding motor. To achieve the fault-tolerant performance of the electric drive system, the redundant fault-tolerant control strategy based on the failure diagnosis and redundancy communication is proposed and applied to the electric drive system. Then, the operational performance of the drive system under open-circuit and short-circuit fault has been verified by simulation and experiments. The research results show that the open-circuit and short-circuit fault can be detected immediately and the output performance of the DFPM motor under fault conditions is almost the same as the normal condition, which verified the proposed electric drive system, DFPM motor, and fault-tolerant control strategy. [ABSTRACT FROM PUBLISHER]

This paper proposes a new electric drive helicopter winch system based on a dual-winding fault-tolerant permanent magnet (DFPM) machine. The proposed DFPM machine consists of an optimal surface-mounted PM rotor and a 12 slots stator with two sets of independent three-phase concentrated armature windings on alternate teeth. Hence, it incorporates the merits of high-power density and high efficiency of a PM machine and high fault-tolerance of a dual-winding machine. To achieve the fault-tolerant performance, the redundant fault-tolerant control strategy based on speed, current, voltage two-way (electric and braking) control is proposed and analyzed first. Then, the electromagnetic performances of the DFPM machine drive system at two open-circuit fault conditions, namely, load hoisting and dropping operation mode, have been verified by experiments. The experimental results show the effectiveness of the proposed fault-tolerant control strategy and the high performance of the fault-tolerant characteristic of the proposed DFPM machine drive. [ABSTRACT FROM AUTHOR]

Periodontitis is a chronic infectious disease characterized by the destruction of connective tissue and alveolar bone that eventually leads to tooth loss. Ferroptosis is an iron-dependent regulated cell death and is involved in ligature-induced periodontitis in vivo. Studies have demonstrated that curcumin has a potential therapeutic effect on periodontitis, but the mechanism is still unclear. The purpose of this study was to investigate the protective effects of curcumin on alleviating ferroptosis in periodontitis. Ligature-induced periodontal-diseased mice were used to detect the protective effect of curcumin. The level of superoxide dismutase (SOD), malondialdehyde (MDA) and total glutathione (GSH) in gingiva and alveolar bone were assayed. Furthermore, the mRNA expression levels of acsl4, slc7a11, gpx4 and tfr1 were measured using qPCR and the protein expression of ACSL4, SLC7A11, GPX4 and TfR1 were investigated by Western blot and immunocytochemistry (IHC). Curcumin reduced the level of MDA and increased the level of GSH. Additionally, curcumin was proven to significantly increase the expression levels of SLC7A11 and GPX4 and inhibit the expression of ACSL4 and TfR1. In conclusion, curcumin plays a protective role by inhibiting ferroptosis in ligature-induced periodontal-diseased mice. [ABSTRACT FROM AUTHOR]

As a cost-effective and well-developed material, graphite is a promising anode material for potassium ion battery due to its high capacity, high tap density, high conductivity and plateau-typed charge curve characteristic. However, graphite suffers from severe capacity fading and poor rate capability. The related research mainstream focuses on electrolyte or binder, aiming at a more robust passivation layer. In contrast, it is not common to transform or modify graphite directly, due to its rigid structure and inert property, which is resistant to gentle chemical treatment. Adjusting coherence length of graphite and its effect on cyclability and rate ability has not been studied yet. Herein, we come up with a strategy of crippling the crystallinity of graphite by strong oxidation first, followed by adjusting coherence length under different pyrolysis temperatures. In the battery test, the expanded graphite pyrolyzed at 750 °C delivers a reversible capacity of 303 mAh/g at a current density of 10 mA/g and 105 mAh/g at a current density of 1000 mA/g. In the long cycling test, a capacity of 160 mAh/g can be maintained after 1000 cycles, with a capacity decay of only 0.02% per cycle. Based on the analysis between coherence length and battery performance, we find that decreasing the coherence length along ab plane contributes to improving rate capability, from both intercalation and pseudo capacitance perspective. Moreover, decreasing the coherence length along c axis contributes to the cyclability. [Display omitted] [ABSTRACT FROM AUTHOR]

This letter presents a modulation technique for the modified coupled-inductor single-stage boost inverter (CL-SSBI)-based grid-connected photovoltaic (PV) system. This technique can reduce the system leakage current in a great deal and can meet the VDE0126-1-1 standard. To maintain the advantages of the impedance network, only a diode is added in the front of the original topology, to block the leakage current loop during the active vectors and open-zero vectors. On the other hand, the near-state pulse width modulation (NSPWM) technique is applied with one-leg shoot-through zero vectors in order to reduce the leakage current through the conduction path in the duration of changing from and to open-zero vectors. Simultaneously, the leakage current caused by other transitions can also be reduced due to the fact that the magnitude of common-mode voltages is reduced. Simulation results of the transformerless PV system are presented in two cases: modified CL-SSBI modulated by maximum constant boost (MCB) control method and NSPWM. Experimental results for both CL-SSBI topology modulated by the MCB control method and modified CL-SSBI topology modulated by NSPWM are also obtained to verify the accurateness of theoretical and simulation models. [ABSTRACT FROM AUTHOR]

This paper presents an optimal scheme of excitation capacitor to decrease the capacity of static excitation controller (SEC) for dual stator-winding induction generator (DWIG) system applied in wind power generation. The investigations into reactive excitation power released by the excitation capacitor and SEC illustrate that the optimal excitation capacitor is not only related to generator parameters, speed range, and load, but also affected by wind turbine power curve. Based on the objective of minimizing the capacity of SEC, several methods are employed here to select an appropriate excitation capacitor. Through the analysis of DWIG control mechanism and model of SEC in the stator-voltage-orientation synchronous d– q frame, a decoupling control strategy using the space vector modulation is obtained. On the basis of this, the simulation and experimental works from the prototype of 18-kW six/three-phase DWIG wind power system are carried out to verify the optimal scheme. The results demonstrate the correctness and effectiveness of this optimization scheme. [ABSTRACT FROM PUBLISHER]

Abstract: Gold nanoparticles in size of about 10nm was used to label goat anti-human complement 3 (anti-C3) to obtain a sensitive and selective immunoresonance scattering spectral probe for C3. It was based on the immune reaction between labeled anti-C3 and C3 in the pH 5.6 Na2HPO4–citric acid buffer solutions and in presence of polyethylene glycol (PEG). The resonance scattering (RS) intensity at 560nm enhanced greatly with C3. Well linear relationships between the enhanced RS intensity (△I RS) and the C3 concentration in the range of 8.33–200ngml−1 were obtained, with a detection limit of 2.8ngml−1 and the limit of quantification 8.51ngml−1 for C3. The convenient and selective and sensitive assay was applied to quantification of C3 in human sera, with satisfactory results. [Copyright &y& Elsevier]

A binuclear Schiff base copper(II) complex [Cu2(L-H)2]Cl2 (1, L = N-(2-hydroxylbenzylidene)-benzo[d]imidazol-2-amine) was synthesized and characterized by elemental analysis, ESI-MS, HRMS, IR, and molar conductivity. Magnetization measurements revealed that 1 showed the usual, moderate-to-strong intramolecular antiferromagnetically coupling exchange interaction between two copper(II) centers. The electrochemical behaviour in DMF showed that 1 has followed quasi-irreversible nature with two successive one-electron reductions as follows: CuIICuII ⇔ CuIICuI ⇔ CuICuI. Complex 1 could bind to DNA by the groove binding mode and electrostatic interaction and induce a conformational variation in DNA. Additionally, 1 could efficiently cleave the supercoiled plasmid DNA into its nicked and linear forms by the oxidative mechanism. The cell experiments showed that 1 could effectively enter cancer cells, even the nucleus, induce cellular apoptosis, and exhibit cytotoxicity comparable to that of cisplatin against HeLa and A549 cell lines; it also has a more potent cytotoxicity against MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

The tumor develops defense tactics, including conversing the mechanical characteristics of tumor cells and their surrounding environment. A recent study reported that cholesterol depletion stiffens tumor cells, which could enhance adaptive T-cell immunotherapy. However, it remains unclear whether reducing the cholesterol in tumor cells contributes to re-educating the stiff tumor matrix, which serves as a physical barrier against drug penetration. Herein, we found that depleting cholesterol from tumor cells can demolish the intratumor physical barrier by disrupting the mechanical signal transduction between tumor cells and the extracellular matrix through the destruction of lipid rafts. This disruption allows nanoparticles (H/S@hNP) to penetrate deeply, resulting in improved photodynamic treatment. Our research also indicates that cholesterol depletion can inhibit the epithelial-mesenchymal transition and repolarize tumor-associated macrophages from M2 to M1, demonstrating the essential role of cholesterol in tumor progression. Overall, this study reveals that a cholesterol-depleted, softened tumor matrix reduces the difficulty of drug penetration, leading to enhanced antitumor therapeutics. [Display omitted] • H/S@hNP could soften the stiff tumor matrix via cholesterol-depletion strategy. • H/S@hNP mediated cholesterol depletion enhanced nanoparticle penetration and photodynamic therapy antitumor efficacy. • H/S@hNP could hamper epithelial-mesenchymal transition and switch tumor-associated macrophages from M2 to M1. [ABSTRACT FROM AUTHOR]

A virtual Hall method for sensorless control of interior permanent magnet synchronous motors (IPMSMs) using high‐frequency signal injection is presented. Based on the idea of virtual Hall, the position signal is easily estimated by comparing the magnitudes of three‐phase inductances. The experimental results prove that the proposed method has good heavy‐load operation capability with a brief control structure. [ABSTRACT FROM AUTHOR]

Visible-infrared person re-identification (VI-ReID) is an emerging and challenging cross-modality image matching problem because of the explosive surveillance data in night-time surveillance applications. To handle the large modality gap, various generative adversarial network models have been developed to eliminate the cross-modality variations based on a cross-modal image generation framework. However, the lack of point-wise cross-modality ground-truths makes it extremely challenging to learn such a cross-modal image generator. To address these problems, we learn the correspondence between single-channel infrared images and three-channel visible images by generating intermediate grayscale images as auxiliary information to colorize the single-modality infrared images. We propose a grayscale enhancement colorization network (GECNet) to bridge the modality gap by retaining the structure of the colored image which contains rich information. To simulate the infrared-to-visible transformation, the point-wise transformed grayscale images greatly enhance the colorization process. Our experiments conducted on two visible-infrared cross-modality person re-identification datasets demonstrate the superiority of the proposed method over the state-of-the-arts. [ABSTRACT FROM AUTHOR]

This letter proposes an integrated ac and dc hybrid generation system based on the dual-stator-winding induction generator with the static excitation controller (SEC). In this generator, not only the power winding can output the variable-frequency ac power, but also the control winding can provide the high-voltage dc power through the dc bus of the SEC, which implements the electric integration by only one generator. An instantaneous slip frequency control strategy is employed to guarantee the system a good performance. The experimental results verify the correctness and effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Core-shell structure particles are synthesized by seeded nucleation, core enlarged polymerization and grafting reaction in the system, which could be tunable by pre-emulsion semi-continuous polymerization. • The particle sizes by batch and pre-emulsion semi-continuous method were compared. • Mechanism of enlarged seed particles process in semi-continuous strategy were explored. • Core shell particles with 380-nm-core provided optimal comprehensive performance. The core-shell polymeric polyacrylate-graft-poly(acrylonitrile-ran-styrene) (ASA) has been explored for the polymer industry due to its excellent properties. However, it has been a longstanding challenge to synthesize large size-tunable particles by the conventional batch polymerization. In this paper, an accurate method, i.e. pre-emulsion semi-continuous polymerization, is applied to prepare ASA polymeric particles, which makes a series of different particle sizes (100–450 nm) of the crosslinked poly(butyl acrylate) (PBA) inner core coated with a hard shell using the poly(acrylonitrile-ran-styrene) (AS) copolymer. Specifically, the feed modes and proportion of seed are investigated to tune the particle size. The results show that the PBA seed microsphere in pre-emulsion semi-continuous polymerization is enlarged by accurate feed rate, but not in batch polymerization. A possible mechanism for the growth of the PBA core is proposed that secondary particles from homogeneous nucleation in semi-continuous feed mode is less than that of batch mode, which attenuate the impact on the growth of core particle. The size and morphology of resulting particles are characterized using various analytical techniques including the transmission electron microscopy (TEM), the scanning electron microscopy (SEM) and the dynamic light scattering (DLS). Core-shell separates phase corresponding to different glass transition temperatures is evaluated using differential scanning calorimeter (DSC) analyses indirectly. Moreover, the mechanical properties including impacts and tensile strengths are also analyzed. This study thus highlights a detailed strategy to tune polymeric particles related to different properties and the nucleating mechanism of seed emulsion polymerization that governs structure, particle size and distribution of ASA polymer with a bespoke structure for various application. [ABSTRACT FROM AUTHOR]

Skin substitutes are designed to promote wound healing by replacing extracellular matrix. Silk-elastin-like protein is a renewable extracellular matrix-like material that integrated the advantages of silk and elastin-like protein. In this study, electrospun silk-elastin-like protein (SELP) nanofiber membrane covered with bacterial cellulose (BC) was created as a potential skin substitute to mimic gradient structure of epidermis and dermis of skin. The two layers were glued together using adhesive SELP containing 3,4-dihydroxyphenylalanine (DOPA) converted from tyrosine by tyrosinase. Skin topical drugs commonly used in clinical practice can penetrate through the SELP/BC barrier, and the rate of penetration is proportional to drug concentration. BC with dense fibrous structure can act as a barrier to preserve the inner SELP layer and prevent bacterial invasion, with a blocking permeation efficiency over 99% against four species of bacteria. Cell experiments demonstrated that the reticular fibers of SELP could provide an appropriate growth environment for skin cells proliferation and adhesion, which is considered to promote tissue repair and regeneration. The promising results support this strategy to fabricate a silk-elastin-like protein-based biomaterial for skin substitutes in the clinical treatment of full skin injuries and ulcers. [Display omitted] • Electrospun SELP acts as a dermal substitute for skin cells proliferation. • BC with favorable penetration serves as epidermal equivalents. • Drugs can penetrate through the skin substitute, while bacteria will be blocked. • Raw materials source from biological origin and meet sustainable production strategy. [ABSTRACT FROM AUTHOR]

Human trophoblast cells are crucial for healthy pregnancy. However, whether the defective homologous recombination (HR) repair of dsDNA break (DSB) in trophoblast cells may induce miscarriage is completely unknown. Moreover, the abundance of BRCA1 (a crucial protein for HR repair), its recruitment to DSB foci, and its epigenetic regulatory mechanisms, are also fully unexplored. In this work, it is identified that a novel lnc‐HZ10, which is highly experssed in villous tissues of recurrent miscarriage (RM) vs their healthy control group, suppresses HR repair of DSB in trophoblast cell. Lnc‐HZ10 and AhR (aryl hydrocarbon receptor) form a positive feedback loop. AhR acts as a transcription factor to promote lnc‐HZ10 transcription. Meanwhile, lnc‐HZ10 also increases AhR levels by suppressing its CUL4B‐mediated ubiquitination degradation. Subsequently, AhR suppresses BRCA1 transcription; and lnc‐HZ10 (mainly 1‐447 nt) interacts with γ‐H2AX; and thus, impairs its interactions with BRCA1. BPDE exposure may trigger this loop to suppress HR repair in trophoblast cells, possibly inducing miscarriage. Knockdown of murine Ahr efficiently recovers HR repair in placental tissues and alleviates miscarriage in a mouse miscarriage model. Therefore, it is suggested that AhR/lnc‐HZ10/BRCA1 axis may be a promising target for alleviation of unexplained miscarriage. [ABSTRACT FROM AUTHOR]