Optically Mediated Nonvolatile Resistive Memory Device Based on Metal-Organic Frameworks.

Metal-organic frameworks (MOFs), characterized by tunable porosity, high surface area, and diverse chemical compositions, offer unique prospects for applications in optoelectronic devices. However, the prevailing research on thin-film devices utilizing MOFs has predominantly focused on aspects such as information storage and photosensitivity, often neglecting the integration of the advantages inherent in both photonics and electronics to enhance optical memory. This work demonstrates a light-mediated resistive memory device based on a highly oriented porphyrin-based MOFs film, in which the resistance state of the memristor is modulated by light, realizing the integration of the perception and storage of optical information. The memristor shows excellent performance with a wide light range of 405-785 nm and a persistent photoconductivity phenomenon up to 8.3 × 103 s. Further mechanistic studies have revealed that the resistive switching effect in the memristor is primarily associated with the reversible formation and annihilation of Ag conductive filaments.

Intratumoral Injection of mRNA Encoding Survivin in Combination with STAT3 Inhibitor Stattic Enhances Antitumor Effects.

Intratumoral delivery of mRNA encoding immunostimulatory molecules can initiate a robust, global antitumor response with little side effects by enhancing local antigen presentation in the tumor and the tumor draining lymph node. Neoantigen-based mRNA nanovaccine can inhibit melanoma growth in mice by intratumoral injection. Myeloid-derived suppressor cells (MDSCs) suppress antitumor immune responses by secreting immunosuppressive agents, such as reactive oxygen species (ROS). Suppression of STAT3 activity by stattic may reduce MDSC-mediated immunosuppression in the TME and promote the antitumor immune responses. In this study, in vitro transcribed mRNA encoding tumor antigen survivin was prepared and injected intratumorally in BALB/c mice bearing subcutaneous colon cancer tumors. In vivo studies demonstrated that intratumoral survivin mRNA therapy could induce antitumor T cell response and inhibit tumor growth of colon cancer. Depletion of CD8+ T cells could significantly inhibit survivin mRNA-induced antitumor effects. RT-qPCR and ELISA analysis indicated that survivin mRNA treatment led to increased expression of receptor activator nuclear factor-κB ligand (RANKL). In vitro experiment showed that MDSCs could be induced from mouse bone marrow cells by RANKL and RANKL-induced MDSCs could produce high level of ROS. STAT3 inhibitor stattic suppressed activation of STAT3 and NF-κB signals, thereby inhibiting expansion of RANKL-induced MDSCs. Combination therapy of survivin mRNA and stattic could significantly enhance antitumor T cell response, improve long-term survival and reduce immunosuppressive tumor microenvironment compared to each monotherapy. In addition, combined therapy resulted in a significantly reduced level of tumor cell proliferation and an obviously increased level of tumor cell apoptosis in CT26 colon cancer-bearing mice, which could be conducive to inhibit the tumor growth and lead to immune responses to released tumor-associated antigens. These studies explored intratumoral mRNA therapy and mRNA-based combined therapy to treat colon cancer and provide a new idea for cancer therapy.

Engineering highly selective CO2 electroreduction in Cu-based perovskites through A-site cation manipulation.

Perovskites exhibit considerable potential as catalysts for various applications, yet their performance modulation in the carbon dioxide reduction reaction (CO2RR) remains underexplored. In this study, we report a strategy to enhance the electrocatalytic carbon dioxide (CO2) reduction activity via Ce-doped La2CuO4 (LCCO) and Sr-doped La2CuO4 (LSCO) perovskite oxides. Specifically, compared to pure phase La2CuO4 (LCO), the Faraday efficiency (FE) for CH4 of LCCO at -1.4 V vs. RHE (reversible hydrogen electrode) is improved from 38.9% to 59.4%, and the FECO2RR of LSCO increased from 68.8% to 85.4%. In situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy spectra results indicate that the doping of A-site ions promotes the formation of *CHO and *HCOO, which are key intermediates in the production of CH4, compared to the pristine La2CuO4. X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and double-layer capacitance (Cdl) outcomes reveal that heteroatom-doped perovskites exhibit more oxygen vacancies and higher electrochemical active surface areas, leading to a significant improvement in the CO2RR performance of the catalysts. This study systematically investigates the effect of A-site ion doping on the catalytic activity center Cu and proposes a strategy to improve the catalytic performance of perovskite oxides.

Br, O-Modified Cu(111) Interface Promotes CO2 Reduction to Multicarbon Products.

Electrochemical reduction of CO2 to multicarbon (C2+) products with added value represents a promising strategy for achieving a carbon-neutral economy. Precise manipulation of the catalytic interface is imperative to control the catalytic selectivity, particularly toward C2+ products. In this study, a unique Cu/UIO-Br interface is designed, wherein the Cu(111) plane is co-modified simultaneously by Br and O from UIO-66-Br support. Such Cu/UIO-Br catalytic interface demonstrates a superior Faradaic efficiency of ≈53% for C2+ products (ethanol/ethylene) and the C2+ partial current density reached 24.3 mA cm-2 in an H-cell electrolyzer. The kinetic isotopic effect test, in situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory calculations have been conducted to elucidate the catalytic mechanism. The Br, O co-modification on the Cu(111) interface enhanced the adsorption of CO2 species. The hydrogen-bond effect from the doped Br atom regulated the kinetic processes of *H species in CO2RR and promoted the formation of *COH intermediate. The formed *COH facilitates the *CO-*COH coupling and promotes the C2+ selectivity finally. This comprehensive investigation not only provides an in-depth study and understanding of the catalytic process but also offers a promising strategy for designing efficient Cu-based catalysts with exceptional C2+ products.

The role of ultraviolet radiation in the flavor formation during drying processing of Pacific saury (Cololabis saira).

BACKGROUND: Traditional sun-drying aquatic products are popular and recognized by customers, owing to their unique flavor and long-term preservation. However, the product quality and production efficiency cannot be guaranteed. Cololabis saira is rich in unsaturated fatty acids, which are susceptible to hyperoxidation during the drying process. This study aimed to make clear the role of ultraviolet (UV) radiation in flavor formation during drying processes of Cololabis saira to develop a modern drying technology. RESULTS: Lipid oxidation analysis revealed that moderate hydrolytic oxidation occurred in the UV-assisted cold-air drying group due to the combined influence of UV and cold-air circulation, resulting in the thiobarbituric acid reactive substances value being higher than that of cold-air drying group but lower than the natural drying group. Hexanal, heptanal, cis-4-heptenal, octanal, nonanal, (trans,trans)-2,4-heptadienal, (trans,trans)-2,6-nonanedial, 1-octen-3-ol, heptanol, 2,3-pentanedione, 3,5-octadien-2-one and trimethylamine were identified as the characteristic flavor odor-active compounds present in all Cololabis saira samples. Yet, during the natural drying process, sunlight promoted the lipid oxidation, resulting in the highest degree of lipid oxidation among three drying methods. Light and heat promoted lipid oxidation in Cololabis saira prepared through natural drying process, leading to a large accumulation of volatile compounds, such as 3-methylbutyraldehyde, 2,3-pentanedione, 1-propanol, and 3-pentanone. Cold air circulation inhibited lipid oxidation to some extent, resulting in a blander flavor profile. More cis-4-heptenal, cis-2-heptenal, octanal and 2-ethylfuran accumulated during the UV-assisted cold-air drying process, enriching its greasy flavor and burnt flavor. CONCLUSION: UV-assisted cold-air drying could promote moderate lipid oxidation, which is beneficial for improving product flavor. To sum up, UV radiation played a crucial role in the flavor formation during the drying process of Cololabis saira. © 2024 Society of Chemical Industry.

Single-atom catalysts based on C2N for sulfur cathodes in Na-S batteries: a first-principles study.

Several major roadblocks, including the "shuttle effect" caused by the dissolved higher-order sodium polysulfides (NaPSs), extremely poor conductivity of sulfur cathodes, and sluggish conversion kinetics of charging-discharging reactions, have hindered the commercialization of sodium-sulfur batteries (NaSBs). In our study, representative C2N-based single-atom catalysts (SACs), TM@C2N (TM = Fe, Ni and V), are proposed to improve the comprehensive performance of NaSBs. Based on first-principles calculations, we first discuss in detail the anchoring behavior of all adsorption systems, TM@C2N/(S8 and NaPSs). The results indicate that compared to pristine C2N, TM@C2N substrates exhibit a stronger capability to capture S8/NaPSs clusters through physical/chemical binding, with V@C2N showing the most outstanding capability ranging from -2.37 to -5.03 eV. The density of states analysis reveals that metallic properties can be well maintained before and after adsorption of polysulfides. More importantly, TM@C2N configurations can greatly reduce the energy barriers of charging and discharging reactions, thereby accelerating the conversion efficiency of NaSBs. It is worth mentioning that V@C2N has lower charge-discharge energy barriers and Na ion migration rates, since the embedded TM atom weakens the strong binding of Na+ in the N6 cavity of C2N. The intrinsic mechanism analysis reveals that the interaction between the d orbitals of V and the p orbitals of S leads to the weakening of Na-S bonds, which can not only effectively inhibit the shuttle effect, but also promote the dissociation of Na2S. Overall, this work not only offers excellent catalytic materials, but also provides vital guidance for designing SACs in NaSBs.

Modulation of host lipid metabolism by virus infection leads to exoskeleton damage in shrimp.

The arthropod exoskeleton provides protection and support and is vital for survival and adaption. The integrity and mechanical properties of the exoskeleton are often impaired after pathogenic infection; however, the detailed mechanism by which infection affects the exoskeleton remains largely unknown. Here, we report that the damage to the shrimp exoskeleton is caused by modulation of host lipid profiles after infection with white spot syndrome virus (WSSV). WSSV infection disrupts the mechanical performance of the exoskeleton by inducing the expression of a chitinase (Chi2) in the sub-cuticle epidermis and decreasing the cuticle chitin content. The induction of Chi2 expression is mediated by a nuclear receptor that can be activated by certain enriched long-chain saturated fatty acids after infection. The damage to the exoskeleton, an aftereffect of the induction of host lipogenesis by WSSV, significantly impairs the motor ability of shrimp. Blocking the WSSV-caused lipogenesis restored the mechanical performance of the cuticle and improved the motor ability of infected shrimp. Therefore, this study reveals a mechanism by which WSSV infection modulates shrimp internal metabolism resulting in phenotypic impairment, and provides new insights into the interactions between the arthropod host and virus.

Effects and microbiota changes following oral lyophilized fecal microbiota transplantation in children with autism spectrum disorder.

Background and purpose: Autism spectrum disorder (ASD) is a group of heterogeneous neurodevelopmental disorders that is characterized by core features in social communication impairment and restricted, repetitive sensory-motor behaviors. This study aimed to further investigate the utilization of fecal microbiota transplantation (FMT) in children with ASD, both with and without gastrointestinal (GI) symptoms, evaluate the effect of FMT and analyze the alterations in bacterial and fungal composition within the gut microbiota. Methods: A total of 38 children diagnosed with ASD participated in the study and underwent oral lyophilized FMT treatment. The dosage of the FMT treatment was determined based on a ratio of 1 g of donor stool per 1 kg of recipient body weight, with a frequency of once every 4 weeks for a total of 12 weeks. In addition, 30 healthy controls (HC) were included in the analysis. The clinical efficacy of FMT was evaluated, while the composition of fecal bacteria and fungi was determined using 16S rRNA and ITS gene sequencing methods. Results: Median age of the 38 children with ASD was 7 years. Among these children, 84.2% (32 of 38) were boys and 81.6% (31 of 38) exhibited GI symptoms, with indigestion, constipation and diarrhea being the most common symptoms. Sample collections and assessments were conducted at baseline (week 0), post-treatment (week 12) and follow-up (week 20). At the end of the follow-up phase after FMT treatment, the autism behavior checklist (ABC) scores decreased by 23% from baseline, and there was a 10% reduction in scores on the childhood autism rating scale (CARS), a 6% reduction in scores on the social responsiveness scale (SRS) and a 10% reduction in scores on the sleep disturbance scale for children (SDSC). In addition, short-term adverse events observed included vomiting and fever in 2 participants, which were self-limiting and resolved within 24 h, and no long-term adverse events were observed. Although there was no significant difference in alpha and beta diversity in children with ASD before and after FMT therapy, the FMT treatment resulted in alterations in the relative abundances of various bacterial and fungal genera in the samples of ASD patients. Comparisons between children with ASD and healthy controls (HC) revealed statistically significant differences in microbial abundance before and after FMT. Blautia, Sellimonas, Saccharomycopsis and Cystobasidium were more abundant in children with ASD than in HC, while Dorea were less abundant. After FMT treatment, levels of Blautia, Sellimonas, Saccharomycopsis and Cystobasidium decreased, while levels of Dorea increased. Moreover, the increased abundances of Fusicatenibacter, Erysipelotrichaceae_UCG-003, Saccharomyces, Rhodotorula, Cutaneotrichosporon and Zygosaccharomyces were negatively correlated with the scores of ASD core symptoms. Conclusions: Oral lyophilized FMT could improve GI and ASD related symptoms, as well as sleep disturbances, and alter the gut bacterial and fungal microbiota composition in children with ASD. Clinical Trial Registration: Chinese Clinical Trial Registry, ChiCTR2200055943. Registered 28 January 2022, www.chictr.org.cn.

Water quality evaluation based on water quality index and multiple linear regression: A research on Hanyuan Lake in southern Sichuan Province, China.

This study aims to understand the changes in the water quality of Hanyuan Lake and to show these changes over time. In this study, monthly sampling was conducted at three sampling sites in Hanyuan Lake, and water samples were measured for water quality indicators in the laboratory according to the methods specified in the Environmental Quality Standards for Surface Water (GB3838-2002). Based on the monitoring data from January to December 2019, the WQI comprehensive evaluation method was used to conduct multiple linear stepwise regression analysis, extract key indicators, and establish the WQImin model. The results show that according to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, and the grade is excellent. The overall water quality of Hanyuan Lake is excellent, and most of the water quality indexes reach the Class I standard in the Environmental Quality Standards for Surface Water (GB3838-2002). WQImin1 (R2 = 0.86, p < 0.001, PE = 4.28) as the best WQImin model. In this study, a model with fewer parameters was established by multiple linear regression method, which is conducive to better monitoring of water quality at monitoring stations while saving costs. PRACTITIONER POINTS: According to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, the rating is excellent. From January 2019 to September 2020, the monthly change trend of each section is roughly the same, showing a trend of first decreasing, then rising, then decreasing, and finally rising and flattening. The WQImin model was developed to completely describe the change in the water body.

Mediating the Role of Perceived Social Support Between Frailty and Self-Perceived Burden in Elderly Patients with Diabetes.

Objective: To explore the mediating effects of perceived social support between frailty and self-perceived burden (SPB) in elderly patients with diabetes and to provide a theoretical basis for reducing that burden. Methods: A total of 169 elderly patients with diabetes who were hospitalised in the endocrinology department of a third-class hospital in Wuxi between May 2020 and July 2022 were included in this study using the convenience sampling method. Patients were assessed by the general information questionnaire, the Chinese version of the Tilburg frailty inventory (TFI), the Self-Perceived Burden Scale (SPBS) and the Perceived Social Support Scale (PSSS). The SPSS 22.0 software was used for Pearson's correlation analysis and multiple linear regression analysis. Model four of the SPSS PROCESS was used for mediating the effect analysis. Results: The SPBS of elderly patients with diabetes was positively correlated with the TFI (P < 0.01) and negatively correlated with the PSSS (P < 0.01). The results of the Bootstrap test showed that the mediating effect of the PSSS on the relationship between the TFI and the SPBS in elderly patients with diabetes was 0.296 (95% CI: 0.007, 0.066), and the mesomeric effect accounted for 17.3% of the total effect. Conclusion: The debilitation of elderly patients with diabetes can be reduced by decreasing their SPB through perceived social support. This can be achieved through comprehensive interventions by nurses.

A Bioinspired Copper-Pair Catalyst in Metal-Organic Frameworks for Molecular Dioxygen Activation and Aerobic Oxidative C-N Coupling.

Open Cu sites were loaded to the UiO-67 metal-organic framework (MOF) skeleton by introduction of flexible Cu-binding pyridylmethylamine (pyma) side chains to the biphenyldicarboxylate linkers. Distance between Cu centers in the MOF pores was tuned by controlling the density of metal-binding side chains. "Interacted" Cu-pair or "isolated" monomeric Cu sites were achieved with high and low (pyma)Cu side chain loading, respectively. Spectroscopic and theoretical studies indicate that "interacted" Cu pairs can effectively bind and activate molecular dioxygen to form Cu2O2 clusters, which showed high catalytic activity for aerobic oxidative C-N coupling. On the contrary, MOF catalyst bearing isolated monomeric Cu sites only showed modest catalytic activity. Enhancement in catalytic performance for the Cu-pair catalyst is attributed to the remote synergistic effect of the paired Cu site, which binds molecular dioxygen and cleaves the O═O bond in a collaborative manner. This work demonstrates that noncovalently interacted metal-pair sites can effectively activate inert small molecules and promote heterogeneous catalytic processes.

Improvement of the catalytic performance of chitosanase Csn-PD from Paenibacillus dendritiformis by semi-rational design.

Chitooligosaccharides (COS) possess versatile functional properties that have found extensive applications across various fields. Chitosanase can specifically hydrolyze ß-1,4 glycosidic bonds in chitosan to produce COS. In this study, Csn-PD, a glycoside hydrolase family 46 chitosanase from Paenibacillus dendritiformis, which produces (GlcN)2 as its main product, was rationally redesigned aiming to improve its catalytic performance. Based on the results of molecular docking analysis and multiple sequence alignment, four amino acid residues in Csn-PD (I101, T120, T220, and Y259) were pinpointed for targeted mutations. Beneficial mutations in terms of enhanced catalytic activity were then combined by site-directed mutagenesis. Notably, the most promising variant, Csn-PDT6 (Csn-PD I101M/T120E/T220G), exhibited an impressive eight-fold surge in activity compared to the wild-type Csn-PD. This heightened enzymatic activity was complemented by an enhanced pH stability profile. A compelling feature of Csn-PDT6 is its preservation of the hydrolytic product profile observed in Csn-PD. This characteristic further accentuates its candidacy for the targeted production of (GlcN)2. The success of our strategic approach is vividly illustrated by the significant improvements achieved in the catalytic performance of the chitosanase, encompassing both its activity and stability. These developments offer a valuable model that may have implications for the semi-rational design of other enzymes.

All-Wood-Based Ionic Power Generator with Dual Functions for Alkaline Wastewater Reuse and Energy Harvesting.

Water-induced electricity harvesting has gained much significance for energy sustainability. Bio-based hydrovoltaic materials increase the attractiveness of this strategy. Although promising, it faces a challenge due to its reliance on fresh water and its inherently low power output. Herein, the energy from alkalinity-gradient power generation demonstrated the feasibility of reuse of alkaline wastewater to develop an all-wood-based water-induced electric generator (WEG) based on ion concentration gradients. The intermittent water droplets bring about uneven distribution of electrolyte and endow delignified wood with the difference of ion concentration along aligned cellulose nanochannels, thus supplying electrical power. The practice of using alkali reservoirs, including industrial wastewater, further contributes to electricity generation. The cubic WEG with a side length of 2 cm can produce an ultrahigh open-circuit voltage of about 1.1 V and a short-circuit current of up to 320 µA. A power output of 6.75 µW cm-2 is correspondingly realized. Series-connected WEGs can be used as an energy source for commercial electronics and self-powered systems. Our design provides a double value proposition, allowing for sustainable energy generation and wastewater reuse.

Bridging Atom Engineering for Low-Temperature Oxygen Activation in a Robust Metal-Organic Framework.

Achieving active site engineering at the atomic level poses a significant challenge in the design and optimization of catalysts for energy-efficient catalytic processes, especially for a reaction with two reactants competitively absorbed on catalytic active sites. Herein, we show an example that tailoring the local environment of cobalt sites in a robust metal-organic framework through substituting the bridging atom from -Cl to -OH group leads to a highly active catalyst for oxygen activation in an oxidation reaction. Comprehensive characterizations reveal that this variation imparts drastic changes on the electronic structure of metal centers, the competitive reactant adsorption behavior, and the intermediate formation. As a result, exceptional low-temperature CO oxidation performance was achieved with T25(Temperature for 25 % conversion)=35 °C and T100 (Temperature for 100 % conversion)=150 °C, which stands out from existing MOF-based catalysts and even rivals many noble metal catalysts. This work provides a guidance for the rational design of catalysts for efficient oxygen activation for an oxidation reaction.

Network pharmacology, molecular docking, and molecular dynamics simulation analysis reveal the molecular mechanism of halociline against gastric cancer.

Halociline, a derivative of alkaloids, was isolated from the marine fungus Penicillium griseofulvum by our group. This remarkable compound exhibits promising antineoplastic activity, yet the precise molecular mechanisms underlying its anticancer properties remain enigmatic. To unravel these mechanisms, we employed an integrated approach of network pharmacology analysis, molecular docking simulations, and molecular dynamics simulations to explore halociline therapeutic targets for gastric cancer. The data from network pharmacology indicate that halociline targets MAPK1, MMP-9, and PIK3CA in gastric cancer cells, potentially mediated by diverse pathways including cancer, lipid metabolism, atherosclerosis, and EGFR tyrosine kinase inhibitor resistance. Notably, molecular docking and dynamics simulations revealed a high affinity between halociline and these targets, with free binding energies (ΔEtotal) of - 20.28, - 27.94, and - 25.97 kcal/mol for MAPK1, MMP-9, and PIK3CA, respectively. This study offers valuable insights into the potential molecular mechanism of halociline's inhibition of gastric cancer cells and serves as a valuable reference for future basic research efforts.

Sub-10-nm-sized Au@AuxIr1-x metal-core/alloy-shell nanoparticles as highly durable catalysts for acidic water splitting.

The absence of efficient and durable catalysts for oxygen evolution reaction (OER) is the main obstacle to hydrogen production through water splitting in an acidic electrolyte. Here, we report a controllable synthesis method of surface IrOx with changing Au/Ir compositions by constructing a range of sub-10-nm-sized core-shell nanocatalysts composed of an Au core and AuxIr1-x alloy shell. In particular, Au@Au0.43Ir0.57 exhibits 4.5 times higher intrinsic OER activity than that of the commercial Ir/C. Synchrotron X-ray-based spectroscopies, electron microscopy and density functional theory calculations revealed a balanced binding of reaction intermediates with enhanced activity. The water-splitting cell using a load of 0.02 mgIr/cm2 of Au@Au0.43Ir0.57 as both anode and cathode can reach 10 mA/cm2 at 1.52 V and maintain activity for at least 194 h, which is better than the cell using the commercial couple Ir/C‖Pt/C (1.63 V, 0.2 h).

Boosting CO2 Electroreduction over a Covalent Organic Framework in the Presence of Oxygen.

Herein, we propose an oxygen-containing species coordination strategy to boost CO2 electroreduction in the presence of O2. A two-dimensional (2D) conjugated metal-covalent organic framework (MCOF), denoted as NiPc-Salen(Co)2-COF that is composed of the Ni-phthalocyanine (NiPc) unit with well-defined Ni-N4-O sites and the salen(Co)2 moiety with binuclear Co-N2O2 sites, is developed and synthesized for enhancing the CO2RR under aerobic condition. In the presence of O2, one of the Co sites in the NiPc-Salen(Co)2-COF that coordinated with the intermediate of *OOH from ORR could decrease the energy barrier of the activation of CO2 molecules and stabilize the key intermediate *COOH of the CO2RR over the adjacent Co center. Besides, the oxygen species axially coordinated Ni-N4-O sites can favor in reducing the energy barrier of the intermediate *COOH formation for the CO2RR. Thus, NiPc-Salen(Co)2-COF exhibits high oxygen-tolerant CO2RR performance and achieves outstanding CO Faradaic efficiency (FECO) of 97.2 % at -1.0 V vs. the reversible hydrogen electrode (RHE) and a high CO partial current density of 40.3 mA cm-2 at -1.1 V in the presence of 0.5 % O2, which is superior to that in pure CO2 feed gas (FECO=94.8 %, jCO=19.9 mA cm-2). Notably, the NiPc-Salen(Co)2-COF achieves an industrial-level current density of 128.3 mA cm-2 in the flow-cell reactor with 0.5 % O2 at -0.8 V, which is higher than that in pure CO2 atmosphere (jCO=104.8 mA cm-2). It is worth noting that an excellent FECO of 86.8 % is still achieved in the presence of 5 % O2 at -1.0 V. This work provides an effective strategy to enable the CO2RR under O2 atmosphere by utilizing the *OOH intermediates of ORR to boost CO2 electroreduction.

Effect of Polygonatum sibiricum saponins on gut microbiota of mice with ulcerative colitis.

Polygonatum sibiricum is a plant with medicinal and nutritional properties. Saponins are the important biologically active components of Polygonatum sibiricum. In this study, the specific components of Polygonatum sibiricum saponins (PSS) were analyzed, and the regulation effect of PSS on intestinal flora in patients with ulcerative colitis (UC) was investigated by inducing male Kunming mice with dextran sulfate sodium (DSS). PSS could ameliorate the symptoms of weight loss, high DAI score and colon length reduction compared to DSS-induced treatment. Colonic fragments were taken for H&E staining and histopathological scoring. PSS could significantly improve the pathological abnormality of colitis mice. 16S rRNA analysis showed that the intestinal microbial community of mice treated with DSS was significantly damaged. PSS could restore the richness and diversity of intestinal microbial flora, reduce the number of pathogenic bacteria, and increase the abundance of Lactobacillus spp. and Muribaculaceae, and improve the intestinal microbial flora disorder. Generally, PSS had an obvious effect in relieving colitis in mice. This study confirmed that Polygonatum sibiricum saponins play a therapeutic and palliative role in ulcerative colitis by regulating the microbiome balance.

Oxygen-tolerant CO2 electroreduction over covalent organic frameworks via photoswitching control oxygen passivation strategy.

The direct use of flue gas for the electrochemical CO2 reduction reaction is desirable but severely limited by the thermodynamically favorable oxygen reduction reaction. Herein, a photonicswitching unit 1,2-Bis(5'-formyl-2'-methylthien-3'-yl)cyclopentene (DAE) is integrated into a cobalt porphyrin-based covalent organic framework for highly efficient CO2 electrocatalysis under aerobic environment. The DAE moiety in the material can reversibly modulate the O2 activation capacity and electronic conductivity by the framework ring-closing/opening reactions under UV/Vis irradiation. The DAE-based covalent organic framework with ring-closing type shows a high CO Faradaic efficiency of 90.5% with CO partial current density of -20.1 mA cm-2 at -1.0 V vs. reversible hydrogen electrode by co-feeding CO2 and 5% O2. This work presents an oxygen passivation strategy to realize efficient CO2 electroreduction performance by co-feeding of CO2 and O2, which would inspire to design electrocatalysts for the practical CO2 source such as flue gas from power plants or air.

A nationwide investigation on the characteristics and health risk of trace elements in surface water across China.

Rapid urbanization accelerates the release of anthropogenic heavy metals from local to wider water systems, posing a serious threat to aquatic ecosystems and public health. The characteristics of trace elements were investigated to evaluate the environmental status of surface water in 40 cities of China. The concentrations of 22 elements in surface water ranged from 7.00 × 10-4 to 4.37 × 105 µg/L. The water quality can be classified as "excellent" except Songhuajiang. The levels of As, Cd, Cr, Pb, and Hg are all within the limits permitted by national drinking water quality standards. An obvious regional distribution characteristic was observed, with concentrations of Zn, Mn, Ni, Cu, Co, U, and Cr higher in surface water collected in the north than in the south, while the trends for Cd, Tl, and As are opposite. Notably, Tl shows significant geographical divergences, with the level of surface water collected from the south nine times higher than that from the north. The regional distribution of the mineral, industrial, or agricultural activity might be responsible for the south-to-north difference of these elements. The hazard index (HI) and total cancer risk (TCR) through oral or dermal contact with water-related heavy metals were further calculated. The average HI was 0.54 in the north and 0.29 in the south for adults, while HI for children was relatively higher. The value was 1.01 and 0.55 in the north and south, respectively. TCR in the north is 2.58 × 10-4 and mainly contributed by Cr (88.1 %), while TCR in the south is 4.48 × 10-5 and mainly contributed by As (98.4 %). The research results can provide essential data for effective water resources management and human health protection in China.