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Steady pressure grouting exhibits the problems of low efficiency and uneven penetration. Therefore, this paper proposes a novel high-frequency pulsating grouting method to improve these problems. Through extensive experimentation and numerical simulations, the impact of pulsating parameters (grouting frequency, pressure amplitude), soil parameters (porosity, particle size), grouting pressure, water–cement ratio, and slurry rheological parameters on slurry penetration is investigated. The results indicate that the stone body grouted by the pulsating pressure is significantly more uniform and has longer penetration distances. During steady pressure grouting, as the grouting pressure or the water–cement ratio increases, the slurry is more prone to flow upward along the interface between the grouting pipe and the soil, which makes the grouted body uneven. When high-frequency pulsating grouting is employed, the slurry tends to flow into the soil, resulting in a more uniform grouted body. In the operating conditions described in this paper, the optimal pulsating frequency is around 3–4 Hz, and the optimal pulse amplitude is approximately 60% of the constant pressure. The results also show that the pulsating grouting method can increase the width by up to 68%. With the increase in porosity and particle size, the percentage of distance increase first increases and then decreases. The percentage of distance increase increases with the increase in viscosity and decreases with the increase in the Bingham rheological parameters ( μ p and τ 0 ). This implies that the pulsating grouting needs certain resistance conditions to achieve optimal penetration performance. The mechanism of pulsating grouting is also analyzed. Pulsating pressure can clear blocked particles and lead to more uniform penetration of the slurry. This study can provide reference for the development of new grouting methods and equipment. [ABSTRACT FROM AUTHOR]

Metabolites play critical roles in macrophage polarization and in their function in response to infection and inflammation. α-aminobutyric acid (AABA), a non-proteinogenic amino acid which can be generated from methionine, threonine, serine, and glycine, has not been studied extensively in relation to macrophage polarization and function. In this study, we aimed to investigate the immunomodulatory function of AABA in regulating M1 macrophage polarization and function in vitro and in vivo. We stimulated bone-marrow-derived macrophages with lipopolysaccharide (LPS) to generate M1 macrophages. Subsequently, we induced sepsis and colitis in mice, followed by treatment with AABA. We then analyzed the samples using ELISA, real-time PCR, Western blotting, flow cytometry, and histopathological analysis to evaluate cytokine secretion, inflammatory gene expression, macrophage activation, disease progression, and inflammation severity. Additionally, metabolomic and chromatin immunoprecipitation-qPCR were conducted to investigate the function of AABA on metabolic reprogramming and epigenetic modifications of M1 macrophages. Our results revealed that AABA inhibited M1 macrophage polarization and function, which led to prolonged survival in septic mice and reduced disease severity in colitis mice. Mechanically, AABA promoted oxidative phosphorylation (OXPHOS) and glutamine and arginine metabolism while inhibiting glycolysis. Moreover, AABA could increase the occupancy of trimethylation of histone H3K27 at the promoter regions of M1 macrophage-associated inflammatory genes, which contributed to the inhibition of M1 macrophage polarization. These findings suggest that AABA may have therapeutic potential for inflammatory diseases by regulating macrophage polarization and function through metabolic and epigenetic pathways. [ABSTRACT FROM AUTHOR]

• The VSC is viewed as a three-port circuit with its port dynamics and couplings at ac and dc sides described by a three-dimensional admittance matrix (3DAM). • The principle and steps to transform the 3DAM to a single-input–single-output (SISO) equivalent form are introduced. The SISO model facilitates an intuitive stability analysis with a single Nyquist curve. • The 3DAM is applied to identify the dominate factor of oscillatory instability. In particular, the instability caused by ac-ac couplings and ac-dc couplings is quantitatively distinguished. The voltage-source converter (VSC) is physically a multi-port circuit consisting ac and dc terminals. The impedance/admittance models (IMs/AMs) of VSC are generally developed considering the frequency-couplings at its ac port, while couplings between ac and dc ports are paid less attention. The ac AM cannot directly reflect oscillatory risks between dc grid and VSC's dc port, and vice versa. This paper proposes a multi-port admittance modeling-based framework to simplify the above modeling and analysis procedure. First, a VSC is viewed as a three-port circuit modeled by a three-dimensional admittance matrix (3DAM). Both ac and dc port dynamics are incorporated into 3DAM with couplings among ports explicitly expressed by off-diagonal elements. Then, the dc and ac grids are easily modeled into 3DAM by sequentially terminating the VSC's three ports with grid impedances. In doing so, the three-port circuit is reduced into a one-port circuit. The principle and steps to transform the 3DAM to a single-input–single-output (SISO) equivalent form are introduced. The resulting SISO model preserves all coupling information in 3DAM and facilitates a more intuitive stability analysis procedure, where a single Nyquist curve suffices. Finally, the 3DAM and SISO model are applied to identify the dominant factors of oscillatory instability. Time-domain simulations validate the effectiveness of the proposed modeling and analysis methods. Index Terms : Admittance matrix, circuit theory, stability criterion, transfer function. [ABSTRACT FROM AUTHOR]

Saturation nonlinearities caused by control limiters will be activated during large disturbances, complicating the stability of grid-tied voltage source converters (VSCs). This letter investigates the large-disturbance synchronization stability of the grid-tied VSC considering two typical control limiters, i.e., the hard limiter of the reference current and the circular limiter used to avoid overmodulation. A unified differential equation (UDE) model is proposed to quantify the transient responses and stability boundaries of the system under different saturation conditions. It is revealed that the VSC behaves as a current source when the hard limiter is activated; while the interaction between the two limiters drives the VSC to work as a voltage source, making it immune to synchronization instability. [ABSTRACT FROM AUTHOR]

Most of the existing stability analysis methods are capable of determining the oscillatory stability of black-box converter interfaced generators (CIGs) under given operating conditions only but can hardly identify the critical operating conditions. In this letter, an oscillatory stability region (OSR) is defined with the short-circuit ratio and output power as variables, and a method to obtain the OSR for the black-box CIG is proposed. First, the CIG is modeled as a variable-operating-point impedance model (VOPIM) through perturbation tests. Then, the critical operating points, for which the CIG system has a zero-damping oscillation mode, are determined by VOPIM-based oscillatory stability analysis so as to obtain the OSR. Finally, the accuracy of the OSR is verified through control hardware-in-the-loop tests. The OSR is of significant meaning for the control strategy and operation plan optimization of the CIGs. [ABSTRACT FROM AUTHOR]

Virtual synchronous generators (VSGs) are effective solutions for low-inertia issues caused by the high penetration of inverter-based resources. However, low-frequency oscillation (LFO) is introduced as a side effect owing to the simulated swing equations in the VSGs. Although LFO has been widely researched in synchronous generator-dominated power systems, the mechanisms and mitigation strategies of VSG-related LFO have been found to be quite distinct. This study presents a comprehensive review of this emerging issue. First, the different causes of VSG-related LFO are sorted, and a unified explanation from the perspective of power-angle dynamics is provided. Then, control strategies to suppress VSG-related LFO are classified, and the advantages, disadvantages, and applicable scenarios of each method are compared. Finally, several topics for future research are discussed, including the aggregation of massive VSGs, wide-area monitoring and source detection, and advanced suppression strategies. • Various mechanisms of virtual synchronous generator (VSG)-related low-frequency oscillation (LFO) are classified and compared with the traditional synchronous generator-related LFO. • Modeling, analysis methods and suppression strategies for the VSG-related LFO are reviewed and compared. • Future research trends for the VSG-related LFO are presented. [ABSTRACT FROM AUTHOR]

Recently, high-frequency resonance (HFR) incidents have occurred in several MMC-HVDC projects. The resonance frequency highly depends on system conditions, making mitigation methods designed for specific scenarios ineffective once the grid condition changes. To address the issue, this paper proposes a novel HFR mitigation method based on adaptive notch filters (ANFs). The embedding positions of ANFs in the MMC control are optimally determined through impedance-based analysis. With the HFR frequency estimated by the interpolated discrete Fourier transform, the parameters of ANFs are adaptively tuned. The ANFs improve the damping performance of the captured HFR mode without affecting the dynamic characteristics at other frequencies. As a result, the HFR under varying grid conditions can be mitigated effectively. The effectiveness of the proposed method is verified through electromagnetic transient (EMT) simulations of an actual MMC-HVDC system. [ABSTRACT FROM AUTHOR]

• The proposed ALPPE method accurately monitor sub-/inter-harmonics during SSI events. • The ALPPE method provides strong robustness against signals with noise. • The ALPPE method is very efficient and capable to perform real-time monitoring. • The ALPPE method can select its processing parameters (model order) adaptively. Sub-Synchronous Interaction (SSI), caused by the increasing penetration of inverter connected nonsynchronous generation, is posing a serious threat on power system stability. As the sub-/inter-harmonics emerging during SSI are featured by time-varying frequencies, concerns regarding the accuracy and the robustness of existing methods for monitoring oscillations of such phenomenon have been raised. This paper proposes a novel two-stage numerical method for monitoring the sub-harmonics, harmonics and inter-harmonics during SSI events. In the first stage, the model order of the estimation is selected using the proposed Adaptive Model Order Selection (AMOS) scheme, which is achieved through singular value decomposition. In the second stage, a linear prediction-based parameter estimation approach with high accuracy and strong robustness is used to estimate the signal parameters of the sub-harmonics, harmonics and inter-harmonics. By merging the above two stages, a novel and effective numerical method is obtained, namely the Adaptive Linear Prediction-based Parameter Estimation (ALPPE) method. In addition, an estimation calibration is implemented to increase the estimation accuracy. The proposed ALPPE method has then been tested using computer simulated signals and field measured data from an actual SSI event. The results of the tests confirmed the ALPPE method's high accuracy, adaptability, processing speed and immunity to noise. [ABSTRACT FROM AUTHOR]

The interactions between permanent magnet synchronous generators (PMSGs) and weak grids may cause negatively damped or growing subsynchronous oscillation (SSO). The growing-SSO would evolve into a sustained-SSO when it is predominantly governed by the nonlinearities in the PMSG's converter control, such as current limiter. Most of the existing frequency-domain modeling and stability analysis methods are in the small-signal sense and thus unable to consider the impact of such nonlinearities. Besides, these methods can hardly give vital information to characterize the sustained-SSO, for instance, the magnitude. This paper presents a detailed characteristic analysis of the sustained-SSO while accounting for the effect of current limiter nonlinearity. First, a single-input-single-output (SISO) frequency-domain model of the PMSG is developed. This SISO model comprises the transfer functions of outer-/inner-loop controls and phase-locked loop (PLL). The nonlinear part, i.e., current limiter, is incorporated into the model using the describing function (DF) method. Then, the equivalent transformation on the system's closed-loop characteristic equation is used to separate the SISO model into independent linear and nonlinear parts. This separation enables the use of the DF-based Nyquist criterion for evaluating the system stability and determining oscillation attributes, such as the magnitude and frequency. Both the analytic results and time-domain simulations reveal that the current limiter has a significant impact on the characteristics of the sustained-SSO. [ABSTRACT FROM AUTHOR]

This paper analytically examines how the condition of weak grid connection affects the torsional sub-synchronous oscillations (SSOs) induced by a grid-connected DFIG in a power system. The examination focuses on the SSO mode of grid-connected DFIG, which is dominated by the phase locked loop (PLL) or DC voltage control. Theoretical analysis is carried out to prove that the condition of weak grid connection amplifies the impact of modal resonance between the DFIG and torsional dynamics of synchronous generators. The amplifying effect of weak grid connection exhibits as the decrease of damping of SSO mode of DFIG and increase of the associated residue when the grid connection weakens. Consequently, the DFIG is more likely to induce torsional SSOs under the condition of weak grid connection, leading to system instability in the worst case. Analytical examination presented in the paper reveals the mechanism about how the condition of weak grid connection plays a key role for the DFIG to induce the torsional SSOs. An example multi-machine power system with the grid-connected DFIG is presented. Results of modal analysis and non-linear simulation using detailed model of DFIG validate the analysis and conclusions made in the paper. [ABSTRACT FROM AUTHOR]

• BESS model which can accurately describe BESS's power regulation behavior and provide a correct state of charge. • Simplifying method to enable the proposed model to finish 24 h-simulation within a few minutes. • BESS-based strategy to improve the AGC performance of wind farms. Battery energy storage system (BESS) is being widely integrated with wind power systems to provide various ancillary services including automatic generation control (AGC) performance improvement. For AGC performance studies, it is crucial to accurately describe BESS's power regulation behavior and provide a correct state of charge (SOC). In addition, BESS model is required to maintain a sufficiently high simulation speed, since it usually is involved in hour- or day-scale simulations. Different from existing models, this paper develops a new BESS model which considers DC-AC converter control, DC link circuit and switching loss, thus providing an accurate power regulation behavior. In addition, it also considers the nonlinear relationship between open-circuit voltage and SOC of battery so that it provides a correct SOC. As a whole, the BESS is simplified as a controlled current source with fundamental frequency (50/60 Hz) and described by algebraic phasor equations to reduce computational burden. This makes the proposed model capable of finishing hour- or day-scale simulations within a few minutes. Time-domain simulations are used to validate and compare the simulation accuracy with the classical first-order transfer function model and electromagnetic model. Based on the proposed model, this paper also introduces and verifies a new BESS-based strategy to improve the AGC performance of wind farms. [ABSTRACT FROM AUTHOR]

• Impedance Network-based Oscillatory Stability Analyzer for grid-connected IBRs is proposed. • Stability and security region analysis can be carried out for all operating points of IBRs. • Stability/region can help avoid oscillatory instability due to control interactions. Unstable subsynchronous oscillations (SSOs) may be excited due to adverse interactions between inverter-based resources (IBRs) and series-compensated or weak ac networks. The frequency-sweep impedance modeling and analysis method is widely used for scanning grid-tied IBRs against the risk of SSO. The stability of such a system is heavily influenced by system-wide parameters such as IBR dispatching conditions (input resource, and different dispatch scenarios), and network status (short-circuit and/or series-compensation levels). The variation in the operating conditions must be taken into account when conducting frequency-scanned impedance-based modeling and analysis. This paper proposes a tool, named impedance network-based oscillatory stability analyzer (INOSA), which integrates decades of research on impedance-based analysis to investigate the risk of SSO under varying operating conditions. The INOSA tool is developed as a MATLAB application package. It takes the available system parameters and frequency-scanned impedance data as input and processes it to carry out impedance network-based stability analysis under all operating conditions. The developed tool outputs key stability information such as damping and frequency of each oscillation mode, and a multi-dimensional security boundary/region plot that can be used to assess the risk of SSO and take appropriate measures. A case study on an actual power system is presented to demonstrate the features and capability of the analysis tool. [ABSTRACT FROM AUTHOR]

• Proposed novel protection scheme against torque amplification for turbine generator. • Method of transient torque estimation to capture the impulsive torque accurately. • Guidance to tune tripping threshold to protect the shaft under various conditions. The torque amplification (TA) in turbine generators connected to a series-compensated network could cause excessive fatigue loss-of-life (FLoL) or even a sudden shaft failure, and thus poses a major threat to the shaft safety. This paper develops an instantaneous transient torque protection (ITTP) scheme to ensure shaft safety. It adopts the shaft speed to estimate transient torque in real-time and then judges whether to trip the generator by comparing the estimated transient torque with the pre-set tripping thresholds. As the key parameters of the proposed protection scheme, the tripping thresholds are delicately tuned based on the most severe circumstance, ensuring the inflicted FLoL less than the tolerable value and avoiding mal-operation under all possible circumstances. A prototype ITTP is developed and its performance is thoroughly verified through real-time digital simulator (RTDS)-based hardware-in-the-loop (HIL) tests on a practical series-compensated power system. The results under a variety of operating conditions and disturbances have well demonstrated the effectiveness of the developed ITTP in estimating transient torque and protecting the generator from damage caused by impulsive transient torque. [ABSTRACT FROM AUTHOR]

This paper concerns with the emerging power system stability issues, classification, and research prospects under a high share of renewables and power electronics. The decades-old traditional power system is undergoing a fast transition with two most prominent features: 1) high-penetration of renewable power generators, utilizing intermittent renewable sources such as wind and solar, and 2) high-penetration of power electronic devices in the generation e.g., wind turbine converters and solar power inverters, transmission e.g., flexible ac or dc transmission system converters, and distribution/utilization systems e.g., electric vehicle and microgrid. The development of modern power systems with dual high-penetrations, i.e., high-penetrations of renewables and power electronic devices, influences the power system dynamics significantly and causes new stability issues. This paper first overviews equipment-level features and system-level stability challenges introduced under the dual high-penetration scenario of the modern power system. Next, the impacts of emerging stability challenges on various aspects of the classical stability issues and classifications are highlighted. Under this context, this paper discusses the validity and limitations of the existing classical and extended power system stability classifications proposed by different IEEE/Cigre Working Groups. Furthermore, a new power system stability classification framework is proposed, which not only maintains the inherent logic of the classical classification but also provides wide coverage and future adaptability of the emerging stability issues. Finally, various classification-oriented research prospects in the power system stability domain are highlighted. • Discussion on the device- and system-level features of power systems with dual high-penetrations. • Emerging stability issues due to dual high-penetrations and their impact on stability classifications. • A critical review of existing classical and extended power system stability classifications of 2004 and 2020. • Highlighting the classification-oriented future research directions. [ABSTRACT FROM AUTHOR]

DC short-circuit fault is a crucial issue in DC grids because the DC fault current increases rapidly with accompanying high fault energy. Limiting the DC fault current is a promising solution to simplify the design of the DC breaker and DC protection. The majority of existing DC fault current limiting (FCL) approaches relies on extra devices, such as DC line inductors. However, the control ability of modular multilevel converters (MMCs) is not optimized. In this study, the submodule (SM) capacitor dynamics during the short DC fault procedure was considered a new control objective, and its effect on the limiting DC fault current was analyzed and revealed. The complex time-varying DC fault transient circuit was comprehensively represented by introducing two base circuit structures and one duty cycle index D. The averaged circuit model was proposed on the basis of the state–space averaging method, which can intuitively show the relation between SM capacitor and DC fault current. The analytical expressions of the DC fault current was given, which can guide the design of the DC FCL control of MMC. The duty cycle index D can represent the discharge of SM capacitors, and the increasing speed of the DC fault current declines with the decrease in D. Accordingly, a feasible FCL control strategy was proposed by choosing D as a tool for affecting and controlling the DC fault current. The proposed FCL control strategy can evidently reduce dc fault current, and avoid the drawbacks of the conventional block or bypass approaches. The simulation results validated the effectiveness of the proposed analysis method and corresponding conclusions. [ABSTRACT FROM AUTHOR]

Background: Acute gastroenteritis is a frequently encountered diarrheal illness in children, often self-limiting but occasionally linked to substantial mortality and morbidity, demanding effective approaches for assessment and intervention. While the utilization of the Pediatric Early Warning Score (PEWS) and the Situation-Background-Assessment-Recommendation system (SBAR) in pediatric patient management is recognized as effective, research in this area remains limited., Objective: Our study aimed to investigate the potential impact of PEWS and SBAR systems on the outcomes of pediatric patients with acute gastroenteritis., Methods: We conducted a randomized controlled trial at our hospital, enrolling 124 children aged 3 to 12 years diagnosed with acute gastroenteritis. These participants were randomly assigned to either a control group (62 cases) or an intervention group (62 cases). Different outcomes were assessed, including the frequency and duration of diarrhea and vomiting, the Modified Vesikari Scale (MVS), the Clinical Dehydration Scale (CDS), and follow-up physician visits. We utilized a two-group independent sample t test to compare outcomes between the two groups., Results: Our study resulted in statistically significant findings favoring the intervention group regarding the frequency and duration of diarrhea and vomiting, the MVS, the CDS, and the need for repeat healthcare visits., Conclusions: The integration of PEWS with SBAR appears to offer improved outcomes for children afflicted with acute gastroenteritis.

Follicular helper T (T FH ) cells provide specialized help for B cells to ensure optimal humoral immunity. The histone methyltransferase EZH2, as a chromatin repressor, secures the T FH differentiation by promoting T FH lineage associated gene expression during acute viral infection, including Tcf7 and Bcl6 . By using conditional deletion murine system, we observed that EZH2 ablation in CD4 + T cells was accompanied by aberrant accumulation of DNA methyltransferases (DNMTs) DNMT1 and DNMT3B in T FH cells. And the loss of EZH2 promoted aggravation of DNA methylation status at Tcf7 locus. Therefore, our findings suggested that EZH2 plays an important role in maintenance of hypomethylation at Tcf7 locus thus affecting T FH differentiation during acute viral infection., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Luo, Li, Xie, Lei, Chen, Wang, Yao, Li, Fang, Chen, Yuan, Li, Xie, Zhang, Li, Hu, Tang, Ye, Wei and He.)

As a key bacterial second messenger, cyclic di-GMP (c-di-GMP) regulates various physiological processes, such as motility, biofilm formation, and virulence. Cellular c-di-GMP levels are regulated by the opposing activities of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs). Beyond that, the enzymatic activities of c-di-GMP metabolizing proteins are controlled by a variety of extracellular signals and intracellular physiological conditions. Here, we report that pdcA ( BTH_II2363 ), pdcB ( BTH_II2364 ), and pdcC ( BTH_II2365 ) are cotranscribed in the same operon and are involved in a regulatory cascade controlling the cellular level of c-di-GMP in Burkholderia thailandensis. The GGDEF domain-containing protein PdcA was found to be a DGC that modulates biofilm formation, motility, and virulence in B. thailandensis. Moreover, the DGC activity of PdcA was inhibited by phosphorylated PdcC, a single-domain response regulator composed of only the phosphoryl-accepting REC domain. The phosphatase PdcB affects the function of PdcA by dephosphorylating PdcC. The observation that homologous operons of pdcABC are widespread among betaproteobacteria and gammaproteobacteria suggests a general mechanism by which the intracellular concentration of c-di-GMP is modulated to coordinate bacterial behavior and virulence. IMPORTANCE The transition from planktonic cells to biofilm cells is a successful strategy adopted by bacteria to survive in diverse environments, while the second messenger c-di-GMP plays an important role in this process. Cellular c-di-GMP levels are mainly controlled by modulating the activity of c-di-GMP-metabolizing proteins via the sensory domains adjacent to their enzymatic domains. However, in most cases how c-di-GMP-metabolizing enzymes are modulated by their sensory domains remains unclear. Here, we reveal a new c-di-GMP signaling cascade that regulates motility, biofilm formation, and virulence in B. thailandensis. While pdcA , pdcB , and pdcC constitute an operon, the phosphorylated PdcC binds the PAS sensory domain of PdcA to inhibit its DGC activity, with PdcB dephosphorylating PdcC to derepress the activity of PdcA. We also show this c-di-GMP regulatory model is widespread in the phylum Proteobacteria . Our study expands the current knowledge of how bacteria regulate intracellular c-di-GMP levels.

Angelica sinensis , a perennial herb that produces ferulic acid and phthalides for the treatment of cardio-cerebrovascular diseases, prefers growing at an altitude of 1800-3000 m. Geographical models have predicted that high altitude, cool temperature and sunshade play determining roles in geo-authentic formation. Although the roles of altitude and light in yield and quality have been investigated, the role of temperature in regulating growth, metabolites biosynthesis and gene expression is still unclear. In this study, growth characteristics, metabolites contents and related genes expression were investigated by exposing A. sinensis to cooler (15 °C) and normal temperatures (22 °C). The results showed that plant biomass, the contents of ferulic acid and flavonoids and the expression levels of genes related to the biosynthesis of ferulic acid ( PAL1 , 4CLL4 , 4CLL9 , C3H , HCT , CCO AMT and CCR ) and flavonoids ( CHS and CHI ) were enhanced at 15 °C compared to 22 °C. The contents of ligustilide and volatile oils exhibited slight increases, while polysaccharide contents decreased in response to cooler temperature. Based on gene expression levels, ferulic acid biosynthesis probably depends on the CCOAMT pathway and not the COMT pathway. It can be concluded that cool temperature enhances plant growth, ferulic acid and flavonoid accumulation but inhibits polysaccharide biosynthesis in A. sinensis . These findings authenticate that cool temperature plays a determining role in the formation of geo-authentic and also provide a strong foundation for regulating metabolites production of A. sinensis .

Though gold mines provide significant economic benefits to local governments, mining causes soil pollution by potentially toxic trace elements (PTEs) in mining areas, especially in the Qinghai-Tibet Plateau. Screening of native plant species from mining areas is now an effective, inexpensive, and eco-friendly method for the remediation of PTEs in situ. In the present study, we conducted experiments to assess the accumulation of As, Cd, Pb, and Zn in 12 native plant species growing on a typical gold mining area in the Qinghai-Tibet Plateau. Our results showed that rhizosphere soils have high soil organic matter content, high levels of As, and moderate levels of Cd. Geranium pylzowianum accumulated relatively higher As in its shoots and exhibited translocation factor (TF) higher than 1 for As (4.65), Cd (1.87), and Pb (1.36). Potentilla saundersiana had bioconcentration factor of shoot (BCF-S) higher than 1 for Cd (4.52) and Pb (1.70), whereas its TF was higher than 1 for As, Cd, Pb, and Zn. These plant species exhibit strong tolerance to these PTEs. Furthermore, Elymus nutans accumulated low levels of As, Cd, Pb, and Zn in their shoots and exhibited TF values lower than 1 for the four PTEs. Therefore, G. pylzowianum is a promising candidate for the in situ phytoextraction of As, and P. saundersiana can be used as an effective plant for Cd and Pb phytoextraction. E. nutans is better suited for the phytostabilisation of multiple PTEs. This work is of significant importance for screening native plant species that can provide a reference for phytoremediation of PTE-contaminated soils in this area or other place with similar climate, and has a good potential for developing PTE phytoremediation strategies at mining sites., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Iron plays a critical role in immune responses. However, its role in T helper cell differentiation and function remains poorly understood. In this study, it is shown that the restraint of iron availability through blocking CD71-mediated iron endocytosis impaired the differentiation and pathogenicity of T H 17 cells. Administrations of anti-CD71 mAb could relieve the development of experimental autoimmune encephalomyelitis (EAE). Mechanistically, the iron deficiency due to the blocking of CD71 enhanced IL-2 expression, which further restrained the differentiation of T H 17 cells. Meanwhile, CD71 blockade impaired histone modifications of Il17 gene and reduced the recruitment of RORγt to Il17a locus. In sum, the findings reveal that iron plays a pivotal role in regulating T H 17 cell differentiation and function in autoimmune diseases., (©2021 Society for Leukocyte Biology.)

This paper applies a neural-network-based approximate dynamic programming method, namely, the direct heuristic dynamic programming (direct HDP), to a large power system stability control problem. The direct HDP is a learning- and approximation-based approach to addressing nonlinear coordinated control under uncertainty. One of the major design parameters, the controller learning objective function, is formulated to directly account for network-wide low-frequency oscillation with the presence of nonlinearity, uncertainty, and coupling effect among system components. Results include a novel learning control structure based on the direct HDP with applications to two power system problems. The first case involves static var compensator supplementary damping control, which is used to provide a comprehensive evaluation of the learning control performance. The second case aims at addressing a difficult complex system challenge by providing a new solution to a large interconnected power network oscillation damping control problem that frequently occurs in the China Southern Power Grid.