Unveiling the methionine cycle: a key metabolic signature and NR4A2 as a methionine-responsive oncogene in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a deadly malignancy with notable metabolic reprogramming, yet the pivotal metabolic feature driving ESCC progression remains elusive. Here, we show that methionine cycle exhibits robust activation in ESCC and is reversely associated with patient survival. ESCC cells readily harness exogenous methionine to generate S-adenosyl-methionine (SAM), thus promoting cell proliferation. Mechanistically, methionine augments METTL3-mediated RNA m6A methylation through SAM and revises gene expression. Integrative omics analysis highlights the potent influence of methionine/SAM on NR4A2 expression in a tumor-specific manner, mediated by the IGF2BP2-dependent stabilization of methylated NR4A2 mRNA. We demonstrate that NR4A2 facilitates ESCC growth and negatively impacts patient survival. We further identify celecoxib as an effective inhibitor of NR4A2, offering promise as a new anti-ESCC agent. In summary, our findings underscore the active methionine cycle as a critical metabolic characteristic in ESCC, and pinpoint NR4A2 as a novel methionine-responsive oncogene, thereby presenting a compelling target potentially superior to methionine restriction.

[Clinical Study of Allogeneic Hematopoietic Stem Cell Transplantation Patients with Co-Reactivation of Cytomegalovirus and Epstein-Barr Virus].

OBJECTIVE: To explore the clinical characteristics and risk factors of cytomegalovirus(CMV) and Epstein-Barr virus(EBV) co-reactivation after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and its influence on prognosis. METHODS: The clinical data of 222 patients who received allo-HSCT from January 2015 to December 2020 were collected, and the patients were divided into groups according to the occurrence of CMV and EBV infection. Kaplan-Meier method was used for survival analysis, and Cox proportional hazard regression model was used to analyze the risk factors of co-reactivation of CMV and EBV. RESULTS: After allo-HSCT, there were 30 patients with co-reactivation of CMV and EBV (CMV++EBV+ group), 101 patients with CMV viremia (CMV+ group), 149 patients with EBV viremia (EBV+ group), and 28 patients with CMV and EBV inactivation (CMV-+ EBV- group). Compared with the other groups, the incidence of acute graft-versus-host disease (aGVHD) and hemorrhagic cystitis (HC) was higher in CMV++ EBV+ groups (53.3% vs 42.6%, 36.9%, 17.9%, P < 0.001; 36.7% vs 32.7%, 22.8%, 10.7%, P =0.042). The incidence of post-transplant lymphoproliferative disease (PTLD) in CMV++ EBV+ group was similar to CMV+ group and EBV+ group (3.3% vs 3.0%, 3.4%, P =0.811). Univariate and multivariate analysis showed that the persistent time of CMV and EBV after transplantation were independent risk factors for co-reactivation of CMV and EBV. Compared with the other groups, the 2-year overall survival (OS) rate and 2-year disease-free survival (DFS) rate of patients in CMV++EBV+ group were lower (46.7% vs 74.9%, 83.4%, 71.4%, P < 0.001; 46.7% vs 70.9%, 79.5%, 69.9%, P =0.002), and 2-year non-recurrence mortality (NRM) was higher (48.2% vs 22%, 13.6%, 18.7%, P <0.001). CONCLUSION: The persistent time of CMV and EBV after transplantation are independent risk factors for patients with co-reactivation of CMV and EBV. Patients with co-reactivation of CMV and EBV had lower OS and DFS rate and higher NRM, suggesting that the clinical prognosis of the patients are worse.

Brunonianines A-C, C20-diterpenoid alkaloids with cyano group from Delphinium brunonianum Royle.

Cyano tends to have better biological activity, but it is rarely reported in natural products, especially in the C20-diterpene alkaloids. Herein, three unprecedented C20-diterpenoid alkaloids, brunonianines A-C (1-3), possessing rare cyano functional group as well as an atisine backbone constructed from a phenethyl substituent and a tetrahydropyran ring, along with four C19-alkaloids (4-7) and one amide alkaloids (8), were isolated from the whole plant of Delphinium brunonianum Royle. Compounds 1-3 are also the first atisine type diterpenoid alkaloids with cyano group obtained from nature. The structures of the previously undescribed compounds were elucidated by HR-ESI-MS, 1D/2D NMR spectroscopic data and electronic circular dichroism calculations and single-crystal X-ray diffraction. Reasonable speculations have also been made regarding the biogenic synthetic pathways of compounds 1-3. In addition, the inhibitory activity of all compounds was also tested against four tumor lines: A549, Caco-2, H460 and Skov-3, where compound 2 (IC50 2.20 ± 0.21 µM) showed better inhibitory activity against Skov-3 cells than the hydroxycamptothecin. Using flow cytometry, cell staining, migration and invasion analysis, and Western blot, compound 2 was found to arrest cells in the G2/M phase and was able to effectively inhibit cell motility to achieve potent anti-tumor effects. In addition, compound 2 can effectively induce apoptosis by activating the Bax/Bcl-2/Caspase-3 signaling pathway.

Influence of facial width on the perception of lip protrusion and its differences between profile and 3-dimensional video clip.

INTRODUCTION: This study evaluated the influence of facial width on the perception of lip protrusion and investigated the concordance between 2-dimensional (2D) profile images and 3-dimensional (3D) video clips in assessing lip protrusion. METHODS: An Asian female standard head model was created using 3D modeling software. Eight head models were constructed by modifying the standard head model in terms of facial width (broad, neutral, and slim) and lip protrusion (retrusive, straight, and protrusive). Overall, 97 Asian raters rated the lip protrusion from the 2D profiles and 3D rotation video clips of the 9 models. RESULTS: No significant differences were found in the perception of lip protrusion in terms of sex, age, or occupation. Compared with the 2D profiles, the 3D video clips were rated as more protrusive in 8 of the 9 head models, with the retrusive broad, retrusive neutral, straight broad, and straight slim faces showing statistical significance (P <0.01). The rating is significantly higher in slim faces than in broad faces across the 3 groups of 2D profiles (P <0.01). For 3D video clips, the rating was higher in slim faces than in broad faces in all 3 groups, whereas differences were significant in the straight and protrusive groups only (P <0.01). CONCLUSIONS: In this study, 3D video clips were more sensitive to the perception of lip protrusion than were 2D profiles to some extent. The lips were rated relatively more protrusive in a slim face than in a broad face. Therefore, the relationship between facial width and lip protrusion should be considered in orthodontic treatment goals and treatment plans.

Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen: The role of Ag-atom and O2.

Carbon nitride has been extensively used as a visible-light photocatalyst, but it has the disadvantages of a low specific surface area, rapid electron-hole recombination, and relatively low light absorbance. In this study, single-atom Ag was successfully anchored on ultrathin carbon nitride (UTCN) via thermal polymerization, the catalyst obtained is called AgUTCN. The Ag hardly changed the carbon nitride's layered and porous physical structure. AgUTCN exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants, eliminations of 85% were achieved by visible-light irradiation for 1 hr. Doping with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 eV and suppressing electron-hole pair recombination. In addition, Ag doping facilitated O2 adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 eV and favored the formation of O2·-. Electron spin resonance and radical-quenching experiments showed that O2·- was the major reactive species in the degradation of Acetaminophen (paracetamol, APAP).

Monoterpene indole alkaloids from Gelsemium elegans.

Two new monoterpene indole alkaloids, Eleganine A (1) and Eleganine B (2), along with 11 known compounds (3-13) were isolated from the stems and leaves of Gelsemium elegans. Compound 1 is a gelsenicine-related monoterpenoid indole alkaloid possessing an iridoid unit. Their structures and absolute configurations of 1-2 were established by UV, IR, HR-ESI-MS, NMR spectroscopy, and electronic circular dichroism data analyses. All isolated compounds were evaluated for their anti-inflammatory and inhibiting glucose-induced mesanginal cell proliferation activities. None of them showed activity with IC50 far beyond 50 µM.

Two new 2-arylbenzo[b]furans from Itea indochinensis and their anti-hepatocellular carcinoma and anti-oxidant effects.

Two new 2-arylbenzo[b]furans (1-2) and ten known compounds (3-12) were identified from the 95% EtOH extract of the branches and leaves of Itea indochinensis for the first time. Their structures were determined mainly based on extensive analyses of UV, IR, 1D/2D NMR and HRMS spectra. The results of MTT assays demonstrated the anti-tumor potential of compound 1 with good selectivity, which displayed moderate inhibitory effects on proliferation of SK-hep-1 cells with IC50 value of 22.3 µM, while weak inhibitory effect on proliferation of HepG2 cells with an inhibition rate of 25% at 20 µM, and no obviously inhibitory effect on proliferation of A549 cells at 20 µM. In addition, compound 1 exhibited its significant scavenging capacity on ABTS·+ free radical with an IC50 value of 0.11 mg/mL, while weak scavenging effects on DPPH and O2·- radicals with scavenging ratios of 32.93% and 21.49% at 1 mg/mL, respectively.

Photocatalysed C-H amidation of indoles enabled by tert-butyl alkyl((perfluoropyridin-4-yl)oxy)carbamate.

Development of a new catalytic and straightforward strategy to construct C-N bonds is playing a pivotal role in synthetic chemistry. Here, we report a photocatalysed protocol to access direct C-H amidation of indoles, enabled by a rationally designed tert-butyl alkyl((perfluoropyridin-4-yl)oxy)carbamate. A series of biologically important aminoindoles were prepared under mild conditions with excellent regioselectivity and broad substrate scope.

Monoterpene indole alkaloids from the roots of Alstonia rupestris and their anti-inflammatory activity.

Four new monoterpene indole alkaloids (1-4) together with twelve known alkaloids (5-16) were isolated from the roots of Alstonia rupestris. Compound 1 was the first example of C2-symmetric heteroyohimbine-type indole alkaloid homodimer obtained from natural plant resource. Their structures were elucidated on the basis of spectroscopic data. The absolute configuration of 1 was determined by comparison of its calculated and experimental electronic circular dichroism (ECD) spectra. All compounds were evaluated for their anti-inflammatory activities by measuring their NO inhibitory effects in LPS-stimulated RAW 264.7 cells. Compound 2 showed strong NO inhibition with IC50 value of 4.2 ± 1.3 µM. Moreover, compound 2 could decrease the expressions of cyclooxygenase-2 (COX-2) and transforming growth factor beta-1 (TGF-ß1).

Risk Factors for Residual Back Pain After PVP Treatment for osteoporotic Thoracolumbar Compression Fractures: A Retrospective Cohort Study.

OBJECTIVES: To explore the risk factors of residual back pain after percutaneous vertebroplasty (PVP) in patients with osteoporotic vertebral compression fracture (OVCF). METHODS: We retrospectively reviewed the records of 675 patients with OVCF treated with PVP from January 2015 to January 2020. Postoperative back pain intensity was assessed by the VAS score. Residual back pain was defined as the presence of postoperative moderate-severe pain (average VAS score≥4), and the variables included patient characteristics, baseline symptoms, imaging data and operation-related factors. Risk factors were identified with univariate and multivariate logistic regression analysis. RESULTS: Residual back pain occurred in 46 of the 675 patients included in the study, with an incidence rate of 6.8%. Multivariate logistic regression analysis showed that low Pre-BMD (OR = 3.576, P = 0.041), multiple vertebral fractures (OR = 2.795, P = 0.026), posterior fascia injury (OR = 4.083, P = 0.032), cement diffusion volume rate <0.2 (OR = 3.507, P = 0.013), facet joint violation (OR = 11.204, P < 0.001), and depression (OR = 3.562, P = 0.035) were positively correlated with residual back pain after PVP. CONCLUSIONS: Low pre-BMD (pre-bone mineral density), multiple vertebral fractures, posterior fascia injury, cement diffusion volume rate <0.2, facet joint violation and depression were the independent risk factors of residual back pain after PVP.

Methylation of BRD4 by PRMT1 regulates BRD4 phosphorylation and promotes ovarian cancer invasion.

Bromodomain-containing protein 4 (BRD4), the major component of bromodomain and extra-terminal domain (BET) protein family, has important functions in early embryonic development and cancer development. However, the posttranslational modification of BRD4 is not well understood. Multiple approaches were used to explore the mechanism of PRMT1-mediated BRD4 methylation and to determine the biological functions of BRD4 and PRMT1 in ovarian cancer. Here we report that BRD4 is asymmetrically methylated at R179/181/183 by PRMT1, which is antagonized by the Jumonji-family demethylase, JMJD6. PRMT1 is overexpressed in ovarian cancer tissue and is a potential marker for poor prognosis in ovarian cancer patients. Silencing of PRMT1 inhibited ovarian cancer proliferation, migration, and invasion in vivo and in vitro. PRMT1-mediated BRD4 methylation was found to promote BRD4 phosphorylation. Compared to BRD4 wild-type (WT) cells, BRD4 R179/181/183K mutant-expressing cells showed reduced ovarian cancer metastasis. BRD4 arginine methylation is also associated with TGF-ß signaling. Our results indicate that arginine methylation of BRD4 by PRMT1 is involved in ovarian cancer tumorigenesis. Targeting PRMT1-mediated arginine methylation may provide a novel diagnostic target and an effective therapeutic strategy for ovarian cancer treatment.

The effect of space arrangement between anterior teeth on their retraction with clear aligners in first premolar extraction treatment: a finite element study.

INTRODUCTION: Clear aligner therapy has become increasingly popular in recent years, although it has encountered several difficulties in premolar extraction treatment. These difficulties include anterior dentition, lingual tipping and extrusion. The design of the present clinical scheme usually set a tiny space between the anterior teeth before retraction in order to obtain an ideal outcome. The objective of our research was to analyze the effect of the existing spaces during retraction. METHODS: Models including maxillary dentition without first premolars, maxilla, periodontal ligaments, gingiva, or aligners were constructed and imported to an ANSYS workbench. Five groups of models were created: without spaces and with 0.25, 0.50, 0.75 and 1.00 mm spaces between the anterior dentition. A 0.20 mm retraction step was applied to all the groups. RESULTS: As the spaces between the anterior dentition increased, the bowing effect of the aligner caused by the passive forces decreased gradually. Accordingly, the degree of extrusion of the anterior dentition was alleviated significantly, while sagittal movement was reduced. However, the overall movement tended to be a bodily displacement rather than tipping. Meanwhile, maximum Von Mises stress of the periodontal ligaments (PDLs) was markedly decreased. CONCLUSION: These analyses indicate that spaces between the anterior dentition during anterior retraction are beneficial for decreasing the tendency for extrusion of the anterior dentition and require provision of anchorage. Appropriate spaces can be designed to lest the lingual tipping and extrusion effect of the anterior teeth while simultaneously reducing the maximum stresses on PDLs.

Enhancing sludge methanogenesis with changed micro-environment of anaerobic microorganisms by Fenton iron mud.

Conductive materials have been demonstrated to enhance sludge methanogenesis, but few researches have concentrated on the interaction among conductive materials, microorganisms and their immediate living environment. In this study, Fenton iron mud with a high abundance of Fe(III) was recycled and applied in anaerobic reactors to promote anaerobic digestion (AD) process. The results show that the primary content of extracellular polymeric substances (EPS) such as polysaccharides and proteins increased significantly, possibly promoting microbial aggregation. Furthermore, with the increment of redox mediators including humic substances in EPS and Fe(III) introduced by Fenton iron mud, the direct interspecies electron transfer (DIET) between methanogens and interacting bacteria could be accelerated, which enhanced the rate of methanogenesis in anaerobic digestion (35.21 ± 4.53% increase compared to the control). The further analysis of the anaerobic microbial community confirmed the fact that Fenton iron mud enriched functional microorganisms, such as the abundance of CO2-reducing (e.g. Chloroflexi) and Fe(III)-reducing bacteria (e.g., Tepidimicrobium), thereby expediting the electron transfer reaction in the AD process via microbial DIET and dissimilatory iron reduction (DIR). This work will make it possible for using the recycled hazardous material - Fenton iron mud to improve the performance of anaerobic granular sludge during methanogenesis.

The effect of CALIPER-derived parameters for idiopathic pulmonary fibrosis in predicting prognosis, progression, and mortality: a systematic review.

BACKGROUND: High-resolution computed tomography (HRCT), as the main tool for monitoring idiopathic pulmonary fibrosis (IPF), is characterized by subjective variability among radiologists and insensitivity to subtle changes. Recently, a few studies have aimed to decrease subjective bias by assessing the severity of IPF using computer software, i.e., Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER). However, these studies had diverse research directions. In this review, we systematically assess the effect of CALIPER in the management of IPF. METHODS: A systematic review was conducted through a search of published studies in PubMed, Web of Science, Cochrane, Embase, Scopus, and CNKI databases from database inception through February 28, 2022. The methodological quality would be evaluated by using Methodological Index for Non-Randomized Studies (MINORS). Narrative synthesis summarized findings by participant characteristics, study design, and associations with outcomes. RESULTS: Ten studies were included. They evaluated the relationship between CALIPER-derived parameters and pulmonary function test (PFT) and mortality. CALIPER-derived parameters showed a significant correlation with PFT and mortality. Two studies reported that CALIPER could be used to stratify outcomes. CONCLUSION: CALIPER-derived parameters can be used to evaluate prognosis and mortality. CALIPER-derived parameters combined with composite physiologic index (CPI) or Gender-Age-Physiology (GAP) could help clinicians implement targeted management by refining prognostic stratification. However, research has been constrained by small number of retrospective investigations and sample sizes. Therefore, it is essential to design prospective controlled studies and establish the staging system by CALIPER-derived parameters and combining them with CPI, FVC, or GAP. CLINICAL RELEVANCE STATEMENT: It is beneficial for clinic to provide objective, sensitive, and accurate indicators of disease progression. It also helps the clinic to develop individualized treatment plans based on the stage of disease progression and provides evaluation of efficacy in drug trials. KEY POINTS: • Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) is a quantitative CT analysis software that can be used to evaluate the progression of disease on CT. • The CALIPER-derived vessel-related structure shows great performance in the management of idiopathic pulmonary fibrosis. • CALIPER-derived parameters combined with composite physiologic index or Gender-Age-Physiology can be used to refine prognostic stratification.

Sugarcane Pulp Take-Out Containers Produce More Microparticles in Acidic Foods.

In the current study, the production of microparticles released from fifteen commercial sugarcane pulp (SCP) take-out containers into different food simulants under different conditions was investigated, where deionized water (DI water), 4% acetic acid (4% HAc), and 95% ethanol (95% EtOH) were used to simulate aqueous, acidic, and fatty foods, respectively. Results showed that compared with DI water and 95% EtOH, 4% HAc caused the degradation of sugarcane fibers, thereby releasing the highest number of microparticles. The overall migration values of the sugarcane pulp take-out containers in 4% HAc were above the prescribed limit of 10 mg/dm2. Furthermore, it was estimated that consumers may intake 36,400-231,700 microparticles in a take-out container at one time, of which the proportion of particles with a particle size between 10 and 500 µm was the highest, ranging from 26,470 to 216,060 items. Moreover, the Al and Fe are the main metals in these take-out containers, ranging between 35.16 and 1244.04 and 44.71 and 398.52 mg/kg, respectively, followed by Pb, Ti, and Sr. This study provides important information that the safety of both the production of microparticles and the metallic elements should be considered for SCP take-out containers when in contact with food.

Authentication of recycled and virgin polyethylene terephthalate based on UPLC-Q-TOF-MS using non-volatile organic compounds and chemometrics.

Plastic packaging waste, such as polyethylene terephthalate (PET) has increased significantly in recent decades, arousing a considerable and serious public concern regarding the environment, economy, and policy. Plastic recycling is a useful tool to mitigate this issue. Here, a feasible study was performed to investigate the potential of a novel method for identifying virgin and recycled PET. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was combined with various chemometrics, as a simple and reliable method that achieved a high discrimination rate for 105 batches of virgin PET (v-PET) and recycled PET (r-PET) based on 202 non-volatile organic compounds (NVOCs). Making use of orthogonal partial least-squares discrimination analysis (OPLS-DA) together with non-parametric tests, 26 marker compounds (i.e. 12 intentionally added substances (IAS) and 14 non-intentionally added substances (NIAS) as well as 31 marker compounds (i.e. 11 IAS and 20 NIAS) obtained from positive and combination of positive and negative ionization modes of UPLC-Q-TOF-MS, respectively, were successfully identified. Moreover, 100% accuracy was obtained using a decision tree (DT). Cross-discrimination based on misclassified samples using various chemometrics allowed the prediction accuracy to be improved and to identify a large sample set, thus greatly enhancing the application scope of this method. The possible origins of these detected compounds can be the plastic itself, as well as contamination from food, medicine, pesticides, industry-related substances, and degradation and polymerization products. As many of these compounds are toxic, especially those pesticide related, this indicates an urgent requirement for closed loop recycling. Overall, this analytical method provides a quick, accurate, and robust way to distinguish virgin from recycled PET and thus addresses the issue of potential virgin PET adulteration thereby detecting fraud in the area of PET recycling.

Direct mapping of bending and torsional dynamics in individual nanostructures.

Investigating coherent acoustic vibrations in nanostructured materials provides fundamental insights into optomechanical responses and microscopic energy flow. Extensive measurements of vibrational dynamics have been performed for a wide variety of nanoparticles and nanoparticle assemblies. However, virtually all of them show that only the dilation modes are launched after laser excitations, and the acoustic bending and torsional motions, which are commonly observed in photoexcited chemical bonds, are absent. Unambiguous identification and refined characterization of these "missing" modes have been a long-standing issue. In this report, we investigated the acoustic vibrational dynamics of individual Au nanoprisms on free-standing graphene substrates using an ultrafast high-sensitivity dark-field imaging approach in four-dimensional transmission electron microscopy. Following optical excitations, we observed low-frequency multiple-mode oscillations and higher superposition amplitudes at nanoprism corners and edges on the subnanoparticle level. In combination with finite-element simulations, we determined that these vibrational modes correspond to out-of-plane bending and torsional motions, superimposed by an overall tilting effect of the nanoprisms. The launch and relaxation processes of these modes are highly pertinent to substrate effects and nanoparticle geometries. These findings contribute to the fundamental understanding about acoustic dynamics of individual nanostructures and their interaction with substrates.

Progress in research on the safety of silicone rubber products in food processing.

Silicone rubber (SR) is widely used in the food processing industry due to its excellent physical and chemical properties. However, due to the differences in SR product production formulas and processes, the quality of commercially available SR products varies greatly, with chemical and biological hazard potentials. Residual chemicals in SR, such as siloxane oligomers and 2,4-dichlorobenzoic acid, are non-intentionally added substances, which may migrate into food during processing so the safe use of SR must be guaranteed. Simultaneously, SR in contact with food is susceptible to pathogenic bacteria growing and biofilm formation, like Cronobacter sakazakii, Staphylococcus aureus, Salmonella enteritidis, and Listeria monocytogenes, posing a food safety risk. Under severe usage scenarios such as high-temperature, high-pressure, microwave, and freezing environments with long-term use, SR products are more prone to aging, and their degradation products may pose potential food safety hazards. Based on the goal of ensuring food quality and safety to the greatest extent possible, this review suggests that enterprises need to prepare high-quality food-contact SR products by optimizing the manufacturing formula and production process, and developing products with antibacterial and antiaging properties. The government departments should establish quality standards for food-contact SR products and conduct effective supervision. Besides, the reusable SR products should be cleaned by consumers immediately after use, and the deteriorated products should be replaced as soon as possible.

Study on 2-arylbenzo[b]furans from Itea omeiensis and their fragmentation patterns with Q-Orbitrap mass spectrometry.

One new 2-arylbenzo[b]furan named iteafuranal F (1) as well as two known analogues (2-3) were isolated from the 95% EtOH extract of aerial parts of Itea omeiensis. Their chemical structures were constructed based on extensive analyses of UV, IR, 1D/2D NMR and HRMS spectra. Antioxidant assays revealed significant superoxide anion radical scavenging capacity of 1 with IC50 value of 0.66 mg/mL, which was comparable to the efficiency of positive control of luteolin. In addition, the preliminary MS fragmentation patterns in negative ion mode were established to distinguish 2-arylbenzo[b]furans with C-10 in different oxidation states: the characteristic loss of CO molecule [M-H-28]- was observed for 3-formyl-2-arylbenzo[b]furans, and the loss of CH2O fragment [M-H-30]- for 3-hydroxymethyl-2-arylbenzo[b]furans, and the loss of CO2 fragment [M-H-44]- for 2-arylbenzo[b]furan-3-carboxylic acids.

Oxygen doping of cobalt-single-atom coordination enhances peroxymonosulfate activation and high-valent cobalt-oxo species formation.

The high-valent cobalt-oxo species (Co(IV)=O) is being increasingly investigated for water purification because of its high redox potential, long half-life, and antiinterference properties. However, generation of Co(IV)=O is inefficient and unsustainable. Here, a cobalt-single-atom catalyst with N/O dual coordination was synthesized by O-doping engineering. The O-doped catalyst (Co-OCN) greatly activated peroxymonosulfate (PMS) and achieved a pollutant degradation kinetic constant of 73.12 min-1 g-2, which was 4.9 times higher than that of Co-CN (catalyst without O-doping) and higher than those of most reported single-atom catalytic PMS systems. Co-OCN/PMS realized Co(IV)=O dominant oxidation of pollutants by increasing the steady-state concentration of Co(IV)=O (1.03 × 10-10 M) by 5.9 times compared with Co-CN/PMS. A competitive kinetics calculation showed that the oxidation contribution of Co(IV)=O to micropollutant degradation was 97.5% during the Co-OCN/PMS process. Density functional theory calculations showed that O-doping influenced the charge density (increased the Bader charge transfer from 0.68 to 0.85 e), optimized the electron distribution of the Co center (increased the d-band center from -1.14 to -1.06 eV), enhanced the PMS adsorption energy from -2.46 to -3.03 eV, and lowered the energy barrier for generation of the key reaction intermediate (*O*H2O) during Co(IV)=O formation from 1.12 to 0.98 eV. The Co-OCN catalyst was fabricated on carbon felt for a flow-through device, which achieved continuous and efficient removal of micropollutants (degradation efficiency of >85% after 36 h operation). This study provides a new protocol for PMS activation and pollutant elimination through single-atom catalyst heteroatom-doping and high-valent metal-oxo formation during water purification.