Twinning Engineering of Platinum/Iridium Nanonets as Turing-Type Catalysts for Efficient Water Splitting.

The twin boundary, a common lattice plane of mirror-symmetric crystals, may have high reactivity due to special atomic coordination. However, twinning platinum and iridium nanocatalysts are grand challenges due to the high stacking fault energies that are nearly 1 order of magnitude larger than those of easy-twinning gold and silver. Here, we demonstrate that Turing structuring, realized by selective etching of superthin metal film, provides 14.3 and 18.9 times increases in twin-boundary densities for platinum and iridium nanonets, comparable to the highly twinned silver nanocatalysts. The Turing configurations with abundant low-coordination atoms contribute to the formation of nanotwins and create a large active surface area. Theoretical calculations reveal that the specific atom arrangement on the twin boundary changes the electronic structure and reduces the energy barrier of water dissociation. The optimal Turing-type platinum nanonets demonstrated excellent hydrogen-evolution-reaction performance with a 25.6 mV overpotential at 10.0 mA·cm-2 and a 14.8-fold increase in mass activity. And the bifunctional Turing iridium catalysts integrated in the water electrolyzer had a mass activity 23.0 times that of commercial iridium catalysts. This work opens a new avenue for nanocrystal twinning as a facile paradigm for designing high-performance nanocatalysts.

SN-38, an active metabolite of irinotecan, enhances anti-PD-1 treatment efficacy in head and neck squamous cell carcinoma.

Anti-programmed cell death 1 (anti-PD-1) therapy shows definite but modest activity in patients with advanced/metastatic head and neck squamous cell carcinoma (HNSCC). Preliminary evidence suggests that SN-38, an activated form of irinotecan that increases expression of the transcription factor FoxO3a, can suppress programmed cell death ligand-1 (PD-L1) expression in breast and ovarian tumor models. We analyzed the SN-38-mediated activation of natural killer cells in vitro and explored the efficacy of SN-38 in combination with anti-PD-1 for treatment in vivo. In vitro, SN-38 enhanced the expression of FoxO3a and reduced the expression of c-Myc and PD-L1 dose-dependently in tumor cells. Low-dose SN-38 increased interferon-γ secretion by NK cells and promoted NK cell-mediated cytotoxicity in tumor cells. In vivo studies revealed that at non-cytotoxic drug concentrations, SN-38 significantly enhanced anti-PD-1 activity in suppressing murine tumor growth. We found increased NK cell and CD8+ T-cell infiltration in post-treatment tumors. RNA-seq analysis indicated that SN-38 increased the enrichment of immune cells and biological function genes related to the immune responses. SN-38 is a potentially beneficial adjunct to checkpoint inhibitor therapy in HNSCC. Further studies exploring its mechanism of action and possible applications are necessary. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Molecular Engineering of a Metal-Organic Polymer for Enhanced Electrochemical Nitrate-to-Ammonia Conversion and Zinc Nitrate Batteries.

Metal-organic framework-based materials are promising single-site catalysts for electrocatalytic nitrate (NO3 - ) reduction to value-added ammonia (NH3 ) on account of well-defined structures and functional tunability but still lack a molecular-level understanding for designing the high-efficient catalysts. Here, we proposed a molecular engineering strategy to enhance electrochemical NO3 - -to-NH3 conversion by introducing the carbonyl groups into 1,2,4,5-tetraaminobenzene (BTA) based metal-organic polymer to precisely modulate the electronic state of metal centers. Due to the electron-withdrawing properties of the carbonyl group, metal centers can be converted to an electron-deficient state, fascinating the NO3 - adsorption and promoting continuous hydrogenation reactions to produce NH3 . Compared to CuBTA with a low NO3 - -to-NH3 conversion efficiency of 85.1 %, quinone group functionalization endows the resulting copper tetraminobenzoquinone (CuTABQ) distinguished performance with a much higher NH3 FE of 97.7 %. This molecular engineering strategy is also universal, as verified by the improved NO3 - -to-NH3 conversion performance on different metal centers, including Co and Ni. Furthermore, the assembled rechargeable Zn-NO3 - battery based on CuTABQ cathode can deliver a high power density of 12.3 mW cm-2 . This work provides advanced insights into the rational design of metal complex catalysts through the molecular-level regulation for NO3 - electroreduction to value-added NH3 .

Factors that affect volume change during electrochemical cycling in cathode materials for lithium ion batteries.

Intergranular cracks originating from volume change during charging/discharging have been observed in many cathodes of lithium ion batteries, which are considered to be closely related to capacity fading. Using first principles calculations to systematically study the volume behavior of representative intercalation cathodes during delithiation, we have elucidated how Coulombic interaction and bond length affect the volume behaviors of cathodes with different structural flexibility. Jahn-Teller distortions, dopants, ionic radii, site-exchanges, and deintercalation mechanisms have also been discussed to account for the volume change of different cathode materials. This study attempts to give an integrated picture of volume change in typical lithium intercalation cathodes and strives to provide helpful clues to the design of high-capacity-maintaining cathodes.

Identification and development of a novel invasion-related gene signature for prognosis prediction in colon adenocarcinoma.

The overall survival of metastatic colon adenocarcinoma (COAD) remains poor, so it is important to explore the mechanisms of metastasis and invasion. This study aimed to identify invasion-related genetic markers for prognosis prediction in patients with COAD. Three molecular subtypes (C1, C2, and C3) were obtained based on 97 metastasis-related genes in 365 COAD samples from The Cancer Genome Atlas (TCGA). A total of 983 differentially expressed genes (DEGs) were identified among the different subtypes by using the limma package. A 6-gene signature (ITLN1, HOXD9, TSPAN11, GPRC5B, TIMP1, and CXCL13) was constructed via Lasso-Cox analysis. The signature showed strong robustness and could be used in the training, testing, and external validation (GSE17537) cohorts with stable predictive efficiency. Compared with other published signatures, our model showed better performance in predicting outcomes. Pan-cancer expression analysis results showed that ITLN1, TSPAN11, CXCL13, and GPRC5B were downregulated and TIMP1 was upregulated in most tumor samples, including COAD, which was consistent with the results of the TCGA and GEO cohorts. Western blot analysis and immunohistochemistry were performed to validate protein expression. Tumor immune infiltration analysis results showed that TSPAN11, GPRC5B, TIMP1, and CXCL13 protein levels were significantly positively correlated with CD4+ T cells, macrophages, neutrophils, and dendritic cells. Further, the TIMP1 and CXCL13 proteins were significantly related to the tumor immune infiltration of CD8+ T cells. We recommend using our signature as a molecular prognostic classifier to assess the prognostic risk of patients with COAD.

Application of a Generative Adversarial Network in Image Reconstruction of Magnetic Induction Tomography.

Image reconstruction of Magnetic induction tomography (MIT) is an ill-posed problem. The non-linear characteristics lead many difficulties to its solution. In this paper, a method based on a Generative Adversarial Network (GAN) is presented to tackle these barriers. Firstly, the principle of MIT is analyzed. Then the process for finding the global optimum of conductivity distribution is described as a training process, and the GAN model is proposed. Finally, the image was reconstructed by a part of the model (the generator). All datasets are obtained from an eight-channel MIT model by COMSOL Multiphysics software. The voltage measurement samples are used as input to the trained network, and its output is an estimate for image reconstruction of the internal conductivity distribution. The results based on the proposed model and the traditional algorithms were compared, which have shown that average root mean squared error of reconstruction results obtained by the proposed method is 0.090, and the average correlation coefficient with original images is 0.940, better than corresponding indicators of BPNN and Tikhonov regularization algorithms. Accordingly, the GAN algorithm was able to fit the non-linear relationship between input and output, and visual images also show that it solved the usual problems of artifact in traditional algorithm and hot pixels in L2 regularization, which is of great significance for other ill-posed or non-linear problems.

Selective Ammonium Removal from Synthetic Wastewater by Flow-Electrode Capacitive Deionization Using a Novel K2Ti2O5-Activated Carbon Mixture Electrode.

Ammonium (NH4+) in wastewater is both a major pollutant and a valuable resource. Flow-electrode capacitive deionization (FCDI) is a promising technology for chemical-free and environmentally friendly NH4+ removal and recovery from wastewater. However, the coexisting sodium (Na+) in wastewater, with a similar hydrated radius to NH4+, competes for the adsorption sites, resulting in low NH4+ removal efficiency. Here, potassium dititanate (K2Ti2O5 or KTO) particles prepared by the electrospray method followed by calcination were mixed with activated carbon (AC) powder to form a novel KTO-AC flow-electrode for selective NH4+ removal over Na+. The mixed KTO-AC electrode exhibits a much higher specific gravimetric capacitance in NH4Cl solution than in NaCl solution. Compared with the pure AC electrode in the FCDI tests on NH4+ removal from synthetic wastewater, 25 wt % KTO addition in the electrode mixture increases the adsorption selectivity from 2.3 to 31 toward NH4+ over Na+, improves the NH4+ removal from 28.5% to 64.8% and increases the NH4+ desorption efficiency from 35.6% to over 80%, achieving selective NH4+ recovery and effective electrode regeneration. Based on DFT calculations, NH4+ adsorption on the K2Ti2O5 (0 0 1) surface is more thermodynamically favorable than that of Na+, which contributes to the high NH4+ adsorption selectivity observed.

High-throughput HSE study on the doping effect in anatase TiO2.

Titania is a widely used semiconductor due to its excellent optoelectronics and catalytic properties. Doping with other cations or anions by substitution of Ti or O is a common way to adjust the electronic structure of pristine TiO2. Here, using ab initio calculations at the Heyd-Scuseria-Ernzerhof (HSE06) level, the substitution energy, formation energy and electronic structures of anatase TiO2 doped with 40 kinds of elements including transition metals, alkali metals, alkaline earth metals, p-block metals, and nonmetals have been studied systematically. It is found that doping with most of these elements can narrow down the band gap of TiO2, while in some doped systems, a recombination center induced by intermediate bands is also observed. Besides, for transition metal-doped TiO2 systems, the electron spin state analysis of dopants and the doping level investigation reveal that a relatively high spin structure tends to be formed in Cr, Mn, Fe, Zn, Mo, Tc, Ru and Cd-doped TiO2, and the doping levels of 4d-orbital transition metals are generally higher than those of 3d-orbital transition metals.

A cross-sectional survey comparing a free treatment program for advanced schistosomiasis japonica to a general assistance program.

The prevalence and intensity of schistosomiasis has dropped dramatically in China due to an effective integrated control program. However, advanced schistosomiasis is becoming a key challenge on the road to elimination. The aims of this study were to compare the disease condition between advanced cases under the general assistance program (GAP) and free treatment program (FTP) and to determine whether the FTP should be popularized to provide an objective reference for policymakers in China's advanced schistosomiasis control program. One hundred and ninety-four patients with schistosomiasis japonica who were enrolled in the GAP or FTP participated in this study. Little significant difference was observed in the potential confounders, including general characteristics, comorbidities, and lifestyle, indicating a similar effect on the pathology of liver damage caused by schistosome infection. There was no apparent difference in the incidence of common clinical symptoms. Furthermore, no significant difference was observed in the ultrasound findings, implying that the GAP and FTP groups shared a similar degree of liver lesion. With the exception of the abnormal rates of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and hyaluronic acid (HA), the other serological indicators were comparable between the groups. Overall, the FTP is not a better option for controlling advanced schistosomiasis in China. It is important to reveal the precise mechanism underlying the pathogenesis of advanced schistosomiasis so that specific approaches to treating and preventing the development of advanced schistosomiasis can be developed and schistosomiasis can be eliminated in China.

Spleen atrophy related immune system changes attributed to infection of Angiostrongylus cantonensis in mouse model.

The spleen is one of the most important peripheral immune organs, which is frequently affected in infectious diseases. Infectious diseases can induce splenic alterations including splenic atrophy and functional alteration, while splenic atrophy may in turn interferes with recovery of infectious diseases. Angiostrongyliasis is an infectious disease by Angiostrongylus cantonensis (A. cantonensis), which invade non-permissive hosts, such as humans and mice, to cause severe damage to the central nervous system (CNS) and acute inflammatory response. A. cantonensis infection-induced CNS injury has been confirmed to be due to profound immunopathology derived from peripheral immune components. However, the mechanism of immunopathology remains largely unknown. Here, we found that A. cantonensis invaded non-permissive hosts such as mice in the brain, but not in the other peripheral organs. However, this infection induced severe spleen atrophy. We further recognized that this atrophy is associated with a decrease of total splenocyte number and disruption of splenic structure due to reduced proliferation and increased apoptotosis. These also resulted in deterioration of T cell profile in the periphery with a low CD4/CD8 ratio and B/T cell ratio, and increased ratio of CD4+CD25+Foxp3+ Treg, CD8+CD28- T, and CD38+T lymphocyte of spleen. Albendazole treatment can alleviate spleen atrophy and set T cell immune reconstitution in some extend. Our data showed that A. cantonensis infection can cause splenic atrophy. These results are suggested to put more emphasis to improve the function of immune system. Meanwhile, infection and treatment model will be useful to evaluate new therapeutic approaches which can prevent or reverse immunosuppression and infectious complications.

Deciphering drug resistance in gastric cancer: Potential mechanisms and future perspectives.

Gastric cancer (GC) is a malignant tumor that originates from the epithelium of the gastric mucosa. The latest global cancer statistics show that GC ranks fifth in incidence and fourth in mortality among all cancers, posing a serious threat to public health. While early-stage GC is primarily treated through surgery, chemotherapy is the frontline option for advanced cases. Currently, commonly used chemotherapy regimens include FOLFOX (oxaliplatin + leucovorin + 5-fluorouracil) and XELOX (oxaliplatin + capecitabine). However, with the widespread use of chemotherapy, an increasing number of cases of drug resistance have emerged. This article primarily explores the potential mechanisms of chemotherapy resistance in GC patients from five perspectives: cell death, tumor microenvironment, non-coding RNA, epigenetics, and epithelial-mesenchymal transition. Additionally, it proposes feasibility strategies to overcome drug resistance from four angles: cancer stem cells, tumor microenvironment, natural products, and combined therapy. The hope is that this article will provide guidance for researchers in the field and bring hope to more GC patients.

Contribution of sphingomyelin phosphodiesterase acid-like 3B to the proliferation, migration, and invasion of ovarian cancer cells.

Background: Cancer has the highest mortality rate among gynecological cancers and poses a serious threat to women's lives. However, the treatment options for ovarian cancer are still limited, and exploring effective targeted biomarkers is particularly important for predicting and treating ovarian cancer. Therefore, it is necessary to explore the molecular mechanisms of the occurrence and development of ovarian cancer. Methods: This investigation encompassed the analysis of gene expression profiles, measurement of transcription levels of potential target genes in peripheral blood samples from ovarian cancer patients and characterization of the ovarian cancer-related secretory protein sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B). Through bioinformatics analysis, potential target genes were identified, and their association with overall survival (OS) and progression-free survival (PFS) in ovarian cancer patients was assessed utilizing relevant databases. Subsequently, differences in target gene expression in ovarian cancer tissue samples were validated through protein blotting and quantitative real-time PCR (qRT-qPCR). Cell proliferation assays using the cell count kit-8 (CCK-8) method, as well as transwell chamber assay and pre coated matrix gel chamber assay were employed to elucidate the role of SMPDL3B in ovarian cancer cell migration and invasion. Results: This study revealed a substantial upregulation of SMPDL3B in the serum of ovarian cancer patients, correlating with an unfavorable prognosis. High SMPDL3B expression was linked not only to increased proliferation of ovarian cancer cells, but also enhanced migration and invasion. Remarkably, the knockdown the human alkaline ceramidase 2 (ACER2) gene in cancer cells with heightened SMPDL3B expression significantly inhibited cell proliferation, migration, and invasion induced by SMPDL3B activation (P<0.05), highlighting the functional interplay between ACER2 and SMPDL3B in ovarian cancer. Conclusions: In summary, this study proposes SMPDL3B as a prognostic marker for ovarian cancer, with implications for potential therapeutic intervention targeting the ACER2-SMPDL3B axis.

Establishment and validation of an extracellular volume model without blood sampling in ST-segment elevation myocardial infarction patients.

Aims: Recent studies have shown that extracellular volume (ECV) can also be obtained without blood sampling by the linear relationship between haematocrit (HCT) and blood pool R1 (1/T1). However, whether this relationship holds for patients with myocardial infarction is still unclear. This study established and validated an ECV model without blood sampling in ST-segment elevation myocardial infarction (STEMI) patients. Methods and results: A total of 398 STEMI patients who underwent cardiac magnetic resonance (CMR) examination with T1 mapping and venous HCT within 24 h were retrospectively analysed. All patients were randomly divided into a derivation group and a validation group. The mean CMR scan time was 3 days after primary percutaneous coronary intervention. In the derivation group, a synthetic HCT formula was obtained by the linear regression between HCT and blood pool R1 (R 2 = 0.45, P < 0.001). The formula was used in the validation group; the results showed high concordance and correlation between synthetic ECV and conventional ECV in integral (bias = -0.12; R 2 = 0.92, P < 0.001), myocardial infarction site (bias = -0.23; R 2 = 0.93, P < 0.001), and non-myocardial infarction sites (bias = -0.09; R 2 = 0.94, P < 0.001). Conclusion: In STEMI patients, synthetic ECV without blood sampling had good consistency and correlation with conventional ECV. This study might provide a convenient and accurate method to obtain the ECV from CMR to identify myocardial fibrosis.

Interaction between microalgae and phycosphere bacteria in a binary cultivation system-based dairy farm wastewater treatment.

The combination of microalgal culture and wastewater treatment is an emerging topic. This study investigated the use of different microalgae to treat different types of dairy farm wastewater. The results showed that the removal of ammonia nitrogen and total phosphorus by mixed microalgae was over 99% and 80%, respectively. The highest production of protein in biomass and extracellular polymeric substances was observed in high-concentration wastewater. In the phycosphere, the abundance of Proteobacteria and Cyanobacteria increased, while that of Bacteroidota decreased. Phycosphere bacteria were strongly correlated with microalgal growth and the composition of extracellular polymeric substances, especially with bound extracellular polymeric substances relative to soluble extracellular polymeric substances. Genes associated with photosynthesis and respiration in phycosphere bacteria were upregulated, contributing to the material exchange capacity in the microalgal-bacterial systems. The interaction between microalgae and phycosphere bacteria thus represents the core of the binary cultivation system-based wastewater treatment and requires further investigation.

Correlation of epicardial adipose tissue and inflammatory indices in patients with STEMI and implications for atrial arrhythmias.

BACKGROUND: Epicardial adipose tissue(EAT) is associated with inflammation in previous studies but is unknown in patients with ST-segment elevation myocardial infarction(STEMI).This study investigated the correlation between epicardial fat and inflammatory cells obtained by cardiac magnetic resonance (CMR) and the effect on atrial arrhythmias in patients with STEMI. METHODS: This was a single-center, retrospective study. We consecutively selected patients who all completed CMR after Percutaneous Coronary Intervention (PCI) from January 2019 to December 2022 and then had regular follow-ups at 1, 3, 6, 9, and 12 months. The enrolled patients were grouped according to the presence or absence of atrial arrhythmia and divided into atrial and non-atrial arrhythmia groups. RESULTS: White blood cell, neutrophil, lymphocyte, C-reactive protein, EATV, LVES, LVED were higher in the atrial arrhythmia group than in the non-atrial arrhythmia group, and LVEF was lower than that in the non-atrial arrhythmia group (p < 0.05); EATV was significantly positively correlated with each inflammatory indices (white blood cell: r = 0.415 p < 0.001, neutrophil:r = 0.386 p < 0.001, lymphocyte:r = 0.354 p < 0.001, C-reactive protein:r = 0.414 p < 0.001); one-way logistic regression analysis showed that risk factors for atrial arrhythmias were age, heart rate, white blood cell, neutrophil, lymphocyte, C-reactive protein, EATV, LVES, LVED; multifactorial logistic regression analysis showed that neutrophil, lymphocyte, C-reactive protein, EATV, and LVES were independent risk factors for atrial arrhythmias; ROC analysis showed that the area under the curve (AUC) for neutrophil was 0.862; the AUC for lymphocyte was 1.95; and the AUC for C-reactive protein was 0.862. reactive protein was 0.852; AUC for LVES was 0.683; and AUC for EATV was 0.869. CONCLUSION: In patients with STEMI, EAT was significantly and positively correlated with inflammatory indices; neutrophil, lymphocyte, C-reactive protein, EATV, and LVES were independent risk factors for atrial arrhythmias and had good predictive value.

Microalgal-bacterial consortia for the treatment of livestock wastewater: Removal of pollutants, interaction mechanisms, influencing factors, and prospects for application.

The livestock sector is responsible for a significant amount of wastewater globally. The microalgal-bacterial consortium (MBC) treatment has gained increasing attention as it is able to eliminate pollutants to yield value-added microalgal products. This review offers a critical discussion of the source of pollutants from livestock wastewater and the environmental impact of these pollutants. It also discusses the interactions between microalgae and bacteria in treatment systems and natural habitats in detail. The effects on MBC on the removal of various pollutants (conventional and emerging) are highlighted, focusing specifically on analysis of the removal mechanisms. Notably, the various influencing factors are classified into internal, external, and operating factors, and the mutual feedback relationships between them and the target (removal efficiency and biomass) have been thoroughly analysed. Finally, a wastewater recycling treatment model based on MBC is proposed for the construction of a green livestock farm, and the application value of various microalgal products has been analysed. The overall aim was to indicate that the use of MBC can provide cost-effective and eco-friendly approaches for the treatment of livestock wastewater, thereby advancing the path toward a promising microalgal-bacterial-based technology.

Wheat Bran Polyphenols Ameliorate DSS-Induced Ulcerative Colitis in Mice by Suppressing MAPK/NF-κB Inflammasome Pathways and Regulating Intestinal Microbiota.

Wheat bran (WB) is the primary by-product of wheat processing and contains a high concentration of bioactive substances such as polyphenols. This study analyzed the qualitative and quantitative components of polyphenols in wheat bran and their effects on ulcerative colitis (UC) using the dextran sulfate sodium (DSS)-induced colitis model in mice. The potential mechanism of wheat bran polyphenols (WBP) was also examined. Our findings indicate that the main polyphenol constituents of WBP were phenolic acids, including vanillic acid, ferulic acid, caffeic acid, gallic acid, and protocatechuic acid. Furthermore, WBP exerted remarkable protective effects against experimental colitis. This was achieved by reducing the severity of colitis and improving colon morphology. Additionally, WBP suppressed colonic inflammation via upregulation of the anti-inflammatory cytokine IL-10 and downregulation of pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß) in colon tissues. Mechanistically, WBP ameliorated DSS-induced colitis in mice by inhibiting activation of the MAPK/NF-κB pathway. In addition, microbiome analysis results suggested that WBP modulated the alteration of gut microbiota caused by DSS, with an enhancement in the ratio of Firmicutes/Bacteroidetes and adjustments in the number of Helicobacter, Escherichia-Shigella, Akkermansia, Lactobacillus, Lachnospiraceae_NK4A136_group at the genus level. To conclude, the findings showed that WBP has excellent prospects in reducing colonic inflammation in UC mice.

Simultaneous Salt Rejection and Heat Localization Via Engineering Macrochannels in Morning Glory-Shaped 3D Evaporator.

Solar desalination is a promising solution for alleviating water scarcity due to its low-cost, environmentally friendly, and off-grid capabilities. However, simultaneous salt rejection and heat localization remain challenging, as the rapid salt convection often results in considerable heat loss. Herein, this challenge is overcome via a facile design: i) isolating high-temperature and high-salt zones by rationally designing morning glory-shaped wick structures and ii) bridging high-salt zones and bulk water with low-tortuosity macrochannels across low-temperature surfaces. The salinity gradient in the macrochannels passively triggers convective flow, facilitating the rapid transfer of salt ions from the high-salt zone to the bulk water. Meanwhile, the macrochannels are spatially isolated from the high-temperature zone, preventing heat loss during salt convection and thereby achieving a high evaporation rate (≈3 kg m-2 h-1) and superior salt rejection even in highly concentrated real seawater. This work provides new insights into salt rejection strategies and advances practical applications for sustainable seawater desalination.

The Electrocatalytic Role of Oxygen Vacancy in Nitrate Reduction Reactions.

Ammonia, with high energy density and easy transportation, holds significant potential to become an integral part of future energy systems. Among tremendous strategies, electrocatalytic ammonia production is no doubt an efficient and eco-friendly method. One particularly intriguing class of electrocatalysts for reducing nitrate to ammonia is transition metal oxides, which have been heavily researched. However, how these catalysts' oxygen vacancy (VO) affects their performance remains elusive. To address this, taking titania (the most important catalyst) as an example, we carried out experimental investigations and simulations. Contrary to the prevailing belief that the concentrated VO would increase the catalytic efficiency of nitrate reduction, it was found that a relatively low level of VO is favorable for maximizing catalytic efficiency. At low cathodic voltages, titania with minimal VO delivered both the highest reduction efficiency and the best selectivity among the different titania samples in this paper. In addition to outlining the merits of lower electron transfer resistance and accelerated reaction dynamics, we also put forth a previously unmentioned factor, the adsorption of hydrogen or the creation of an ordered hydrogen bond network, which put up a hydrogen-rich atmosphere for following nitrate reduction. Further simulation study revealed that within the hydrogen-rich atmosphere isolated VO serves as the ideal active center to enable the lowest energy barriers for the reduction of nitrate into ammonia. These findings offer fresh insights into the working mechanism of oxide-based electrocatalysts for ammonia production.

Regulation and microbial response mechanism of nitric oxide to copper-containing swine wastewater treated by Pistia stratiotes.

As a signaling molecule, Nitric oxide (NO) has been widely used in abiotic stress mitigation studies.Pistia stratiotes showed a good synergistic removal effect on heavy metals, nitrogen and phosphorus, but the high concentration of copper(Cu) in swine wastewater inhibited the comprehensive removal ability of Pistia stratiotes. At present, it is not clear how the addition of NO regulates the stress resistance mechanism of Pistia stratiotes to copper in swine wastewater, and the microbial response mechanism accompanying this process is not yet clear. Therefore, in the concentration range of 0.31∼4 mg·L-1Cu2+ and NO concentration of 0,0.05 and 0.1 mg L-1, the removal effect of Pistia stratiotes on copper from swine wastewater was studied. The results showed as follows: The treatment of non-available copper in groups M and H increased by 10.67% and 22.31%, respectively, compared with that in group L. The critical point of inhibiting effect of NO on growth rate was 2.03 mg·L-1Cu. By measuring three-dimensional fluorescence spectrum, combined with parallel factor analysis and principal component analysis, it was confirmed that exogenous addition of NO affected the humification degree of dissolved organic matter(DOM) and promoted the chelation of organic matter with copper. With the increase of Cu concentration, the Reyranella and Prosthecobacter with certain copper resistance gradually gained advantages. Redundancy analysis(RDA) showed that Emiticicia had a strong correlation with the removal rates of ammonia nitrogen, total phosphorus and copper in swine wastewater, while hgcI_clade had a strong correlation with the removal rates of total nitrogen. In conclusion, controlling the dosage of NO can effectively improve the tolerance and removal effect of Pistia stratiotes on copper in swine wastewater, which is of great significance for promoting the treatment and resource transformation of swine wastewater.