Magnetic MoS2/Fe3O4 composite as an effective activator of persulfate for the degradation of tetracycline: performance, activation mechanisms and degradation pathways.

The activated persulfate (PS) process could produce sulfate radical (SO4·-) and rapidly degrade organic pollutants. The application of Fe3O4 as a promising PS activator was limited due to the rapid conversion of Fe2+ to Fe3+ on its surface. Mo4+ on MoS2 surface could be used as a reducing site to convert Fe3+ to Fe2+, but the separation and recovery of MoS2 was complex. In this study, MoS2/Fe3O4 was prepared to accelerate the Fe3+/Fe2+ cycle on Fe3O4 surface and achieved efficient separation of MoS2. The results showed that MoS2/Fe3O4 was more effective for PS activation compared to Fe3O4 or MoS2, with a removal efficiency of 91.8% for 20 mg·L-1 tetracycline (TC) solution under the optimal conditions. Fe2+ and Mo4+ on MoS2/Fe3O4 surface acted as active sites for PS activation with the generation of SO4•-, •OH, •O2-, and 1O2. Mo4+ acted as an electron donor to promote the Fe3+/Fe2+ cycling and thus improved the PS activation capability of MoS2/Fe3O4. The degradation pathways of TC were inferred as hydroxylation, ketylation of dimethylamino group and C-N bond breaking. This study provided a promising activated persulfate-based advanced oxidation process for the efficient degradation of TC by employing MoS2/Fe3O4 as an effective activator.

Dissipation and Risk Assessment of Propaquizafop in Ginseng under Field Conditions.

Propaquizafop is a highly efficient aryloxy phenoxy propionate chiral herbicide. However, the use of propaquizafop, including its safe use methods, residue patterns, dietary risk assessment, and maximum residue limits, for ginseng, a traditional Chinese medicinal plant, has not been studied. An analytical method was established for the simultaneous determination of propaquizafop and its four metabolites in ginseng soil, fresh ginseng, ginseng plant, and dried ginseng using HPLC-MS/MS. This approach showed good linearity (R2 ranging from 0.9827 to 0.9999) and limit of quantification ranging from 0.01 to 0.05 mg/kg. The intra- and interday recovery rates of this method ranged from 71.6 to 107.1% with relative standard deviation ranging from 1.3 to 23.2%. The method was applied to detect residual samples in the field, and it was found that the degradation of propaquizafop in ginseng plants and soil followed a first-order kinetic equation. R2 was between 0.8913 and 0.9666, and the half-life (t1/2) ranged from 5.04 to 8.05 days, indicating that it was an easily degradable pesticide (T1/2 < 30 days). The final propaquizafop residues in ginseng soil, plants, fresh ginseng, and dried ginseng ranged from 0.017 to 0.691 mg/kg. A dietary risk assessment was conducted on the final propaquizafop residue in fresh and dried ginseng. The results showed that the chronic exposure risk quotient values were less than 100% for fresh and dried ginseng (1.15% for fresh ginseng and 1.13% for dried ginseng). This illustrates that the dietary risk associated with the use of 10% propaquizafop emulsifiable concentrate in ginseng is very low. Thus, applying 750 mL/ha of propaquizafop on ginseng could not pose an unacceptable risk to public health. The results of the present study support the registration of propaquizafop in ginseng.

Efficient surface defect identification for optical components via multi-scale mixed Kernels and structural re-parameterization.

Surface defect identification plays a vital role in defective component rapid screening tasks in optics-related industries. However, the weakness and complexity of optical surface defects pose considerable challenges to their effective identification. To this end, a deep network based on multi-scale mixed kernels and structural re-parameterization is proposed to identify four manufacturing and two non-manufacturing optical surface defects. First, we design a multi-size mixed convolutional kernel with multiple receptive fields to extract rich shallow features for characterizing the defects with varying scales and irregular shapes. Then, we design an asymmetric mixed kernel integrating square, horizontal, vertical, and point convolutions to capture rotationally robust middle-and-deep features. Moreover, a structural re-parameterization strategy is introduced to equivalently convert the multi-branch architecture in the training phase into a deploy-friendly single-branch architecture in the inference phase, so that the model can obtain higher inference speed without losing any performance. Experiments on an optical surface defect dataset demonstrate that the proposed method is efficient and effective. It achieves a remarkable accuracy of 97.39% and an ultra-fast inference speed of 201.76 frames/second with only 5.23M parameters. Such a favorable accuracy-speed trade-off is capable of meeting the requirements of real-world optical surface defect identification applications.

Surface weak scratch detection for optical elements based on a multimodal imaging system and a deep encoder-decoder network.

The detection of surface weak scratches is an intractable but vital task in optics-centered industries. However, the intrinsic characteristics of weak scratches, such as a narrow width, long span, and shallow depth, make it extremely difficult to effectively detect these scratches. In this paper, we tackle this issue from two perspectives. First, a multimodal microscopic imaging system is created by combining discrete multispectral illumination with linear polarization. Imaging experiments demonstrated that this system could highlight more scratch details, improve image clarity, and alleviate the image blur problem induced by wide spectrum scattered lights. Second, a scratch-oriented U-shaped deep encoder-decoder network equipped with optimized residual encoding modules, serial-parallel multiscale fusion modules, and triple-convolution decoding modules is proposed to segment the weak scratches from a raw image. The detection experiments demonstrate that our model can accurately segment the weak scratches on optical surfaces and achieve better detection performance using significantly fewer parameters compared to similar deep learning models. Meanwhile, experiments on the building crack dataset prove the excellent generalization capability.

Spillover effects of RMB exchange rate among RCEP member countries: Empirical evidence from time-frequency domain approach.

This study employs time-frequency domain approach to investigate the spillover effects of renminbi (RMB) exchange rate among the Regional Comprehensive Economic Partnership (RCEP) member countries. Utilizing daily data spanning from August 2010 to August 2022, we find that currencies in the RCEP region demonstrate significant interaction, which is primarily driven by short-term spillover, and ascend in response to major economic and political events. With respect to the influence of RMB, it displays frequency bands heterogeneity. Specifically, RMB tends to be a net receiver in the short term, but it primarily functions as a net transmitter in the long term. Notably, our analysis of time-varying spillover effects indicates that both domestic exchange rate regime reforms and external political and economic shocks amplify the net spillover effects of the RMB, which may be reflected in short-term connectedness or captured by long-term connectedness.

In situ performance and stability tests of large-area flexible polymer solar cells in the 35-km stratospheric environment.

Flexible organic solar cells (FOSCs) are one of the most promising power sources for aerospace aircraft due to their attractive advantages with high power-per-weight ratio and excellent mechanical flexibility. Understanding the performance and stability of high-performance FOSCs is essential for the further development of FOSCs for aerospace applications. In this paper, after systematic investigations on the performance of the state-of-the-art high-performance solar cells under thermal cycle and intensive UV irradiation conditions, in situ performance and stability tests of the solar cells in the 35 km stratospheric environment were carried out through a high-altitude balloon uploading. The encapsulated FOSCs with an area of 0.64 cm2 gave the highest power density of 15.26 mW/cm2 and an efficiency over 11%, corresponding to a power-per-weight ratio of over 3.32 kW/kg. More importantly, the cells showed stable power output during the 3-h continuous flight at 35 km and only 10% performance decay after return to the lab, suggesting promising stability of the FOSCs in the stratospheric environment.

Catalytic ozonation mechanisms of Norfloxacin using Cu-CuFe2O4.

As an easily recoverable, environmentally friendly and cost-effective catalyst, CuFe2O4 is a promising candidate for the catalytic ozonation of antibiotics in wastewater. However, its catalytic activity is restricted due to its limited active sites and low electron transfer efficiency. In this study, cetyl trimethyl ammonium bromide (CTAB) and Cu0 were doped with CuFe2O4 to introduce more OV, providing more active sites and improving electron transfer efficiency. Experimental results show that the optimum removal efficiency of the catalytic ozonation of Norfloxacin (NOR, a widely used antibiotic) using CTAB doped with Cu-CuFe2O4 as the catalyst is 81.58% with a first-order reaction kinetics constant of 0.03967 min-1. The associated O3 and catalyst dosages are 2.72 mg·L-1 and 0.1 g·L-1, respectively, which are 1.63 times and 2.22 times higher than those in an equivalent O3 system. OV can provide generation sites for surface hydroxyl groups and trigger ·O2- and 1O2 as the main active oxygen species. The synergistic redox cycles of Fe2+/Fe3+ and Cu0/Cu2+ accelerate electron transfer efficiency. The possible degradation pathways of NOR are identified as defluorination, naphthyridine ring-opening and piperazine ring-opening. In summary, this work proposes a new strategy for the modification of CuFe2O4 catalysts and provides new insights into the catalytic ozonation mechanisms for NOR removal.

Contribution of nitrous oxide to the carbon footprint of full-scale wastewater treatment plants and mitigation strategies- a critical review.

Nitrous oxide (N2O), a potent greenhouse gas, significantly contributes to the carbon footprint of wastewater treatment plants (WWTPs) and contributes significantly to global climate change and to the deterioration of the natural environment. Our understanding of N2O generation mechanisms has significantly improved in the last decade, but the development of effective N2O emission mitigation strategies has lagged owing to the complexity of parameter regulation, substandard monitoring activities, and inadequate policy criteria. Based on critically screened published studies on N2O control in full-scale WWTPs, this review elucidates N2O generation pathway identifications and emission mechanisms and summarizes the impact of N2O on the total carbon footprint of WWTPs. In particular, a linear relationship was established between N2O emission factors and total nitrogen removal efficiencies in WWTPs located in China. Promising N2O mitigation options were proposed, which focus on optimizing operating conditions and implementation of innovative treatment processes. Furthermore, the sustainable operation of WWTPs has been anticipated to convert WWTPs into absolute greenhouse gas reducers as a result of the refinement and improvement of on-site monitoring activities, mitigation mechanisms, regulation of operational parameters, modeling, and policies.

12.42% Monolithic 25.42 cm2 Flexible Organic Solar Cells Enabled by an Amorphous ITO-Modified Metal Grid Electrode.

Printed metal nanogrid electrode exhibits superior characteristics for use in flexible organic solar cells (OSCs). However, the high surface roughness and inhomogeneity between grid and blank region is adverse for performance improvement. In this work, a thin amorphous indium tin oxide (ITO) film (α-ITO) is introduced to fill the blank and to improve the charge transporting. The introduction of α-ITO significantly improves the comprehensive properties of metal grid electrode, which exhibits excellent bending resistance and long-term stability under double 85 condition (under 85 °C and 85% relative humidity) for 200 h. Both experimental and simulation results reveal α-ITO with a sheet resistance of 20 000 Ω â–¡-1 is sufficient to improve the charge transporting within the adjacent grids, leading to a remarkable efficiency of 16.54% for 1 cm2 flexible devices. With area increased to 4.00, 9.00, and 25.42 cm2 , the devices still display a performance of 16.22%, 14.69%, and 12.42%, respectively, showing less efficiency loss during upscaling. And the 25.42 cm2 monolithic flexible device exhibits a certificated efficiency of 12.03%. Moreover, the device shows significantly improved air stability relative to conventional high-conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate-modified device. All these make the α-ITO-modified Ag/Cu electrode promise to achieve high-efficient and long-term stable large-area flexible OSCs.

Applications of Sponge Iron and Effects of Organic Carbon Source on Sulfate-Reducing Ammonium Oxidation Process.

The typical characteristics of wastewater produced from seafood, chemical, textile, and paper industries are that it contains ammonia, sulfate, and a certain amount of chemical oxygen demand (COD). The sulfate-reducing ammonium oxidation process is a biochemical reaction that allows both ammonia and sulfate removal, but its low growth rate and harsh reaction conditions limit its practical application. Due to the adsorption properties of the iron sponge and its robust structure, it provides a suitable living environment for microorganisms. To reduce the negative impact on the environment, we employed 4.8 kg of sponge iron in a 2.0 dm3 anaerobic sequencing batch reactor (ASBR). We investigated the effects of the type and concentration of carbon sources on the performance of the sulfate-reducing ammonium oxidation (SRAO) process. The results demonstrated that during a start-up period of 90 days, the average ammonium removal efficiency and the sulfate conversion efficiency of the reactor containing the sponge iron were 4.42% and 8.37% higher than those of the reactor without the sponge iron. The addition of the sponge iron shortens the start-up time of this greenhouse gas-free denitrification process and reduces future costs in practical applications. The removal of total nitrogen (TN) significantly increased after adding organic carbon sources and then declined sharply, while the most considerable reduction of ammonium removal efficiency from 98.4% to 30.5% was observed with adding phenol. The performance of the group employing glucose as the carbon source was recovered on the 28th day, with the average ammonium removal efficiency increasing from 49.03% to 83.5%. The results of this simulation study will help the rapid start-up of SRAO in the water treatment industry and can precisely guide the application of the SRAO process for wastewater containing different organic carbon sources.

The performance of electrode ultrafiltration membrane bioreactor in treating cosmetics wastewater and its anti-fouling properties.

The membrane fouling problem of the membrane bioreactor (MBR) for wastewater treatment reduces the membrane flux and the pollutants removal efficiencies, which is the major obstacle limiting its application and should be properly solved. The combination of membrane and electricity can effectively slow down the membrane fouling rate due to electric repulsion between the pollutants and the membrane. In this study, the performance and the membrane fouling features of an electrode ultrafiltration membrane bioreactor (EMBR) fed with cosmetics wastewater were compared with a conventional ultrafiltration membrane bioreactor (UMBR). The results showed the COD removal efficiency increased by 4.43% and the transmembrane pressure (TMP) reduced by 50% in the EMBR as compared with the UMBR. The specific surface areas of electrode ultrafiltration membrane and conventional ultrafiltration membrane declined by 56.9% and 78.8% after 90 days of operation, respectively. The Protein (PN), polysaccharide (PS) and humic acids (HA) in the cake layer of EMBR were only 61.27%, 78.37% and 34.85% of that of UMBR, which contributed to its loose and porous structure and thus decreased the growth rate of TMP and extended the operation cycle. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory calculation proved that the energy barrier between the electrode ultrafiltration membrane and the pollutants was 50% higher than that between the conventional ultrafiltration membrane and the pollutants. Therefore, the strong anti-fouling property of the electrode ultrafiltration membrane could reduce the chemicals dosage and manpower consumption for membrane cleaning and could be preferred for the treatment of cosmetics or alike wastewater containing high concentrations of surfactants and fatty acids.

Phosphorus removal from wastewater using electric arc furnace slag aggregate.

Electric arc furnace (EAF) slag aggregate, a waste by-product of the steel industry, exhibited a high potential for phosphorus (P) removal and had attracted considerable attention. The main objectives of this study were to evaluate the performance of using EAF slag aggregate as an adsorbent for P removal and identify its P removal capacity. A series of batch tests showed that P removal capacity of EAF slag increases gradually with the increase of pH with a range of 2-10, while the highest P removal capacity (1.94 mg/g) can be obtained at pH 12. The adsorption kinetics of P on EAF slag can be described by pseudo-second-order kinetic equations. Isothermal adsorption simulations showed that the best fitted model was the Freundlich model with a correlation coefficient of 0.9825. A continuous flow column experiment feeding a synthetic influent containing 15 mg P/L was operated for 60 days and the P removal efficiency was greater than 95% with a P removal capacity of 1.6 mg P/g slag. The results obtained in this study showed that EAF slag could act as an efficient adsorbent for P removal. Calcium phosphate precipitation depends on the release of Ca2+ and OH- by the dissolution of calcium oxide in EAF slag was found to be the dominant removal mechanism for P removal.

Gut Microbiota in Patients with Polycystic Ovary Syndrome: a Systematic Review.

Polycystic ovary Syndrome (PCOS) is one of the most popular diseases that cause menstrual dysfunction and infertility in women. Recently, the relationships between the gastrointestinal microbiome and metabolic disorders such as obesity, type 2 diabetes and PCOS have been discovered. However, the association between the gut microbiome and PCOS symptoms has not been well established. We systematically reviewed existing studies comparing gut microbial composition in PCOS and healthy volunteers to explore evidence for this association. A systematic search was carried out in PubMed, Embase, Cochrane Library, and Web of Science from inception to May 26, 2020, for all original cross-sectional, cohort, or case-control studies comparing the fecal microbiomes of patients with PCOS with microbiomes of healthy volunteers (controls). The primary outcomes were differences in specific gut microbes between patients with PCOS and controls. The search identified 256 citations; 10 studies were included. The total population study of these articles consists of 611 participants (including PCOS group and healthy controls group). Among the included 10 studies, nine studies compared α-diversity, and six studies demonstrated that α-diversity has a significant reduction in PCOS patients. Seven of them reported that there was a significant difference of ß-diversity composition between healthy controls groups and PCOS patients. The most common bacterial alterations in PCOS patients included Bacteroidaceae, Coprococcus, Bacteroides, Prevotella, Lactobacillus, Parabacteroides, Escherichia/Shigella, and Faecalibacterium prausnitzii. No consensus has emerged from existing human studies of PCOS and gut microbiome concerning which bacterial taxa are most relevant to it. In this systematic review, we identified specific bacteria associated with microbiomes of patients with PCOS vs controls. Higher level of evidence is needed to determine whether these microbes are a product or cause of PCOS.

Microbial community competition rather than high-temperature predominates ARGs elimination in swine manure composting.

Aerobic composting is commonly used in pig manure treatment, however, antibiotic resistance genes (ARGs) and their unclear transformation during composting process make the treated manure land using risky. The effects of enhanced thermophilic phase strategy (external heating (HTC) and thermophiles inoculation (MC)) on ARGs removal and the underlying mechanisms were investigated during swine manure composting. HTC increased the total relative abundance (RA) of ARGs by 32.38%, and MC decreased by 21.50% compared to CK by the end of the composting. Mantel test indicated that it was not temperature (P > 0.05), but environmental parameters (pH, Electric Conductivity (EC), etc.) and metabolic products (nitrogen forms) significantly affected the ARGs profile. Partial least-squares path modeling (PLS-PM) suggested that microbial community structure (bacterial abundance and diversities) was the main factor for ARGs evolution. Co-occurrence analysis revealed that HTC could promote the propagation of ARG hosts in later stage of the composting because the strong selection of thermophiles resulted in ecological niches vacancy, and MC enhanced the competition between hosts and nonhosts for ecological niches by increasing thermophiles diversities. These results suggested that competitive inhibition to potential ARGs hosts could be a helpful strategy in ARGs threaten elimination during composting.

Numerical Failure Analysis and Fatigue Life Prediction of Shield Machine Cutterhead.

This paper presents numerical failure analysis on cracking of shield machine cutterhead structure during a metro-tunnel construction. The stress intensity factors (SIFs) of surface cracks with different shapes and location angles were analyzed by a finite element simulation method based on linear elastic fracture mechanics (LEFM) theory. The ratios of variation in stress intensity factors of cracks with different shapes were analyzed. The maximum allowable crack depth of the cutterhead panel is 50.23 mm by dynamic stress calculation, and the damage tolerance criterion of the cutterhead panel was proposed. The influence of the Paris model parameter values was analyzed based on mathematical methods. It is proven that the location of the cutterhead cracking angle is mainly determined by the mixed-mode SIF. In practice, the crack section basically expanded into the semi-elliptical shape. The cutterhead structure may directly enter the stage of crack propagation due to welding defects during tunneling. The research results provide a theoretical basis and important reference for crack detection in the key parts of the cutterhead, as well as maintenance cycle determination and life prediction of the cutterhead mileage, both of which have important engineering value.

The effect of bacterial functional characteristics on the spread of antibiotic resistance genes in Expanded Granular Sludge Bed reactor treating the antibiotic wastewater.

To explore the fate and spreading mechanism of antibiotics resistance genes (ARGs) in antibiotics wastewater system, a laboratory-scale (1.47 L) Expanded Granular Sludge Bed (EGSB) bioreactor was implemented. The operating parameters temperature (T) and hydraulic retention time (HRT) were mainly considered. This result showed the removal of ARGs and COD was asynchronous, and the recovery speed of ARGs removal was slower than that COD removal. The decreasing T was attributed to the high growth rate of ARGs host bacteria, while the shortened HRT could promote the horizontal and vertical gene transfer of ARGs in the sludge. The analysis result of potential bacterial host showed more than half of the potential host bacteria carried 2 or more ARGs and suggested an indirect mechanism of co-selection of multiple ARGs. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to investigate the functional characteristics of bacterial community. This result showed the bacterial functional genes contributed 40.41% to the abundance change of ARGs in the sludge, which was higher that of bacterial community. And the function genes of "aromatic hydrocarbon degradation", "Replication, recombination and repair proteins" and "Flagellar assembly" were mainly correlated with the transfer of ARGs in the sludge. This study further revealed the mechanism of ARGs spread in the EGSB system, which would provide new ideas for the development of ARGs reduction technology.

Effects of nurse-led web-based interventions on people with type 2 diabetes mellitus: A systematic review and meta-analysis.

INTRODUCTION: Diabetes mellitus is an expanding global health problem. Currently, the home management of diabetes is mainly led by a multidisciplinary team based on telemedicine. However, the role nurses play in it remains inconclusive. This study aimed to investigate the effectiveness of nurse-led web-based intervention on glycated haemoglobin, blood pressure and lipid profile in patients with type 2 diabetes. METHODS: An exhaustive systematic literature search was undertaken using the following databases: PubMed, Web of Science, Embase, The Cochrane Central Register of Controlled Trials and CINAHL. Two investigators independently extracted data and assessed the quality of the studies by examining the risk of bias and using Modified Jadad Score system. We conducted a meta-analysis of randomized controlled trials that had been published from inception to July 2020, using Review Manager 5.3. RESULTS: Eleven randomized controlled trials were selected that included 2063 participants. Meta-analyses results indicated significant effects on not only glycated haemoglobin (pooled mean difference (MD) = -0.40, 95% confidence interval (CI): -0.5 to -0.26, p < 0.00001), but also on systolic blood pressure (pooled MD = -1.91, 95% CI: -3.73 to -0.09, p = 0.04) and low density lipoprotein (pooled standardized MD = -0.29, 95% CI: -0.44 to -0.15, p < 0.0001). There were no effects of nurse-led web-based intervention on fasting blood glucose, diastolic blood pressure, high density lipoprotein, body mass index and triglycerides. DISCUSSION: Nurse-led web-based intervention is a promising way to complement routine clinical care. However, the specific intervention content and intervention media still need to carry out large-scale well-designed randomized controlled trials. Systematic review registration: PROSPERO CRD 42020204565.

Nitrous oxide emission in a laboratory anoxic-oxic process at different influent pHs: Generation pathways and the composition and function of bacterial community.

This study focused on the nitrous oxide (N2O) generation from the biological nitrogen removal process under different pH levels. To explore a pH optimum, the online N2O emission and the bacterial composition and function in the anoxic-oxic process were investigated. The mean gaseous N2O emission accounted for 0.329%, 0.103%, 0.085%, and 0.793% of the influent total nitrogen at pH of 5, 6, 8, and 9, respectively. Incomplete oxidation in oxic tanks was the primary source of N2O, while N2O in the anoxic tank was mainly generated by nitrifier denitrification. No direct correlations were observed between N2O emission and potential nitrifiers and denitrifiers. The impacts of pH on N2O generation were more likely related to the response of bacterial enzymes and nitrogen compounds, rather than the feedback of bacterial community structure itself. Above all, an influent pH range of 6-8 is recommended for nitrogen removal and N2O mitigation in anoxic-oxic process.

Effects of graphite particles/Fe3+ on the properties of anoxic activated sludge.

In order to improve the sludge flocculation, the combination of graphite particles/Fe3+ was used to change the sludge properties and accelerate the electron transfer rate. The effects of Fe3+ on the properties of graphite particles were investigated and the synergistic effects of graphite particles/Fe3+ on the sludge properties were analyzed using N2-adsorption/desorption, scanning electron microscopy-X-ray energy dispersive analysis (SEM-EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that the operation time affected the specific surface area and pore size of graphite particles. The addition of Fe3+ reduced the specific surface area and increased the pore size of graphite particles, but it did not change the crystal structure of the graphite particles and the group structure of the sludge. Under the function of graphite particles/Fe3+, Zeta potential were improved and the relative hydrophobicity of the sludge was weakened. The contact angle was slightly lowered and flocculation ability (FA) was increased. Therefore, graphite particles/Fe3+ played an important role in the charge transfer and bioflocculation improvement.

EZH2 deficiency attenuates Treg differentiation in rheumatoid arthritis.

The chromatin modifier enhancer of zeste homolog 2 (EZH2) methylates lysine 27 of histone H3 (H3K27) and regulates T cell differentiation. However, the potential role of EZH2 in the pathogenesis of rheumatoid arthritis (RA) remains elusive. We analyzed EZH2 expression in PBMC, CD4+ T cells, CD19+ B cell, and CD14+ monocytes from active treatment-naïve RA patients and healthy controls (HC). We also suppressed EZH2 expression using EZH2 inhibitor GSK126 and measured CD4+ T cell differentiation, proliferation and apoptosis. We further examined TGFß-SMAD and RUNX1 signaling pathways in EZH2-suppressed CD4+ T cells. Finally, we explored the regulation mechanism of EZH2 by RA synovial fluid and fibroblast-like synoviocyte (FLS) by neutralizing key proinflammatory cytokines. EZH2 expression is lower in PBMC and CD4+ T cells from RA patients than those from HC. EZH2 inhibition suppressed regulatory T cells (Tregs) differentiation and FOXP3 transcription, and downregulated RUNX1 and upregulated SMAD7 expression in CD4+ T cells. RA synovial fluid and fibroblast-like synoviocytes suppressed EZH2 expression in CD4+ T cells, which was partially neutralized by anti-IL17 antibody. Taken together, EZH2 in CD4+ T cells from RA patients was attenuated, which suppressed FOXP3 transcription through downregulating RUNX1 and upregulating SMAD7 in CD4+ T cells, and ultimately suppressed Tregs differentiation. IL17 in RA synovial fluid might promote downregulation of EZH2 in CD4+ T cells. Defective EZH2 in CD4+ T cells might contribute to Treg deficiency in RA.