ABSTRACT
Covalent organic frameworks (COFs), with their accessible nanoscale porosity, selectable building blocks, and precisely engineered topology, offer unique benefits in the design of room-temperature phosphorescent (RTP) materials. However, their potential has been limited by phosphorescence quenching caused by interlayer π-π stacking interactions. This paper presents a novel strategy to enhance RTP in heavy-atom-free COFs by employing a donor-acceptor (D-A) system that leverages the Förster resonance energy transfer (FRET) and Dexter energy transfer (DET) mechanisms. Among the materials investigated, the best-performing COF exhibits a phosphorescence lifetime of 4.35 ms at room temperature. Spectral analysis, structural analysis, and theoretical calculations indicate the presence of intralayer FRET processes as well as interlayer DET processes within the D-A COF system. Potential anti-counterfeiting applications are explored by exploiting the unique phosphorescent properties of these materials. Additionally, the inherent permanent porosity of COFs presents new opportunities for future development and application. This strategy offers many promising prospects for advancing the RTP technology in COF materials and broadens their potential applications in various fields.
ABSTRACT
Ovarian cancer (OC) is the fifth most common cause of death in women worldwide. Chemoresistance is a key reason for treatment failure, causing high mortality. As a member of the tripartite motif-containing (TRIM) protein family, tripartite motif 47 (TRIM47) plays a vital role in the carcinogenesis and drug resistance of various cancers. This study investigated the impact and mechanisms of TRIM47 on cisplatin (DDP) chemosensitivity and apoptosis in OC. OC cell viability was assessed with a cell counting kit-8 assay and OC cell apoptosis was assessed using flow cytometry, caspase-3 and caspase-9 activity, and Bax and Bcl-2 expression assays while gene and protein expression were assessed using qRT-PCR and Western blot assays. The expression of TRIM47 was significantly increased in both DDP-resistant tissues from patients with OC tissues and in cancer cell lines compared with that in normal tissue or parental cell lines. The increased level of TRIM47 correlated with poor prognosis in patients with OC. Functional assays demonstrated that TRIM47 promoted DDP resistance both in vitro and in vivo. The increased viability and reduced apoptosis of OC cells induced by TRIM47 can be rescued by the endoplasmic reticulum (ER) stress-inducer tunicamycin, suggesting that TRIM47 inhibits OC cell apoptosis by suppressing ER stress. Therefore, TRIM47 may be targeted as a therapeutic strategy for DDP resistance in OC.
ABSTRACT
The increasing ground-level ozone (O3) is threatening food security, especially in Asian areas, where rice is one of the most important staple crops. O3 impacts on rice could be exacerbated by its spatiotemporal heterogeneity. To improve evaluation accuracy and develop effective adaptations, direct data is urgently needed. Studies on the short-term effects of O3 on rice grain, however, are lacking. Which may lead to an underestimation of the O3 impacts. Through a field experiment, we studied the responses of grain nitrogen, grain carbon, and grain protein in rice cultivars to elevated concentrations of O3 (40 ppb plus that in background air, eO3), especially examining the effects of short-term eO3 during different plant growth stages. We found that long-term eO3 increased grain nitrogen by 29.29% in a sensitive rice cultivar, and short-term eO3 at the tillering and jointing stages increased grain nitrogen by 19.31%, and the grain carbon to nitrogen ratio was decreased by 14.70%, and 21.14% by short-term and long-term eO3. Here we demonstrate that short-term eO3 may significantly affect the chemical composition of rice grains. Previous evaluations of the effects of eO3 may be underestimated. Moreover, changes in the grain nitrogen and grain protein were greater when the short-term eO3 was added to rice plants during the tillering and jointing stage, compared to heading and ripening stage. These results suggest that to improve the tolerance of rice to eO3 to achieve food security, studies on cultivar screening, as well as developing growth-stage-specific adaptations are needed in future.
Subject(s)
Air Pollutants , Nitrogen , Oryza , Ozone , Oryza/growth & development , Air Pollutants/analysis , Air Pollutants/toxicity , Nitrogen/analysis , Edible Grain/chemistry , Carbon/analysis , Environmental MonitoringABSTRACT
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.
Subject(s)
Colonic Neoplasms , Cyclic S-Oxides , Mice, Inbred BALB C , RNA, Messenger , STAT3 Transcription Factor , Survivin , Animals , Survivin/genetics , Survivin/antagonists & inhibitors , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/antagonists & inhibitors , STAT3 Transcription Factor/metabolism , RNA, Messenger/genetics , Colonic Neoplasms/therapy , Colonic Neoplasms/immunology , Colonic Neoplasms/pathology , Colonic Neoplasms/genetics , Cyclic S-Oxides/pharmacology , Cell Line, Tumor , Injections, Intralesional , Myeloid-Derived Suppressor Cells/immunology , Myeloid-Derived Suppressor Cells/drug effects , Tumor Microenvironment/drug effects , Mice , Female , Reactive Oxygen Species/metabolism , CD8-Positive T-Lymphocytes/immunology , Cell Proliferation , Inhibitor of Apoptosis Proteins/genetics , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Humans , Tumor Burden/drug effects , Signal TransductionABSTRACT
Chlorinated paraffins (CPs) are chlorinated alkane mixtures widely used as flame retardants and plasticizers in multiple industrial products. Systematic research on how homolog-specific properties affect their atmospheric behaviors is limited. Herein, we investigated the levels of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in long-timescale, seasonal, and size-fractioned particles in the urban area of Dalian, a coastal city in northern China. The average SCCP and MCCP concentrations in particles with diameters ≤ 10 µm were 3.36 and 4.89 ng/m3, respectively, and a general increase in the SCCP concentration was observed from 2.59 ng/m3 in 2018 - 2019 to 7.84 ng/m3 in 2021 - 2023. CP levels and patterns showed significant seasonal variation, with a higher abundance of C11-13Cl7-9 in winter and C10-12Cl5 in summer. Elevated particle levels in winter and high temperatures in summer contributed to the seasonal variations. SCCPs and MCCPs were concentrated on particles with diameters of < 1 µm and their geometric mean diameter increased with the increasing carbon and chlorine numbers. Total Daily intake of SCCP and MCCP was calculated to be 0.15 and 0.22 ng/kg bw/day for adults. 53.1 %, 8.5 %, and 38.4 % of inhaled SCCPs, and 60.6 %, 7.6 %, and 31.8 % of inhaled MCCPs deposited into the head airway, tracheobronchial region, and alveolar region, respectively. This study reports on how homolog-specific physicochemical properties alter the temporal variations, size distributions, and inhaled fractions of CPs.
ABSTRACT
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.
ABSTRACT
A copper porphyrin-derived metal-organic framework electrocatalyst, FICN-8, was synthesized and its catalytic activity for CO2 reduction reaction (CO2RR) was investigated. FICN-8 selectively catalyzed electrochemical reduction of CO2 to CO in anhydrous acetonitrile electrolyte. However, formic acid became the dominant CO2RR product with the addition of a proton source to the system. Mechanistic studies revealed the change of major reduction pathway upon proton source addition, while catalyst-bound hydride (*H) species was proposed as the key intermediate for formic acid production. This work highlights the importance of electrolyte composition on CO2RR product selectivity.
ABSTRACT
CO2 electroreduction (CO2RR) to generate valuable chemicals in acidic electrolytes can improve the carbon utilization rate in comparison to that under alkaline conditions. However, the thermodynamically more favorable hydrogen evolution reaction under an acidic electrolyte makes the CO2RR a big challenge. Herein, robust metal phthalocyanine(Pc)-based (M = Ni, Co) conductive metal-covalent organic frameworks (MCOFs) connected by strong metal tetraaza[14]annulene (TAA) linkage, named NiPc-NiTAA and NiPc-CoTAA, are designed and synthesized to apply in the CO2RR in acidic electrolytes for the first time. The optimal NiPc-NiTAA exhibited an excellent Faradaic efficiency (FECO) of 95.1% and a CO partial current density of 143.0 mA cm-2 at -1.5 V versus the reversible hydrogen electrode in an acidic electrolyte, which is 3.1 times that of the corresponding metal-organic framework NiPc-NiN4. The comparison tests and theoretical calculations reveal that in-plane full π-d conjugation MCOF with a good conductivity of 3.01 × 10-4 S m-1 accelerates migration of the electrons. The NiTAA linkage can tune the electron distribution in the d orbit of metal centers, making the d-band center close to the Fermi level and then activating CO2. Thus, the active sites of NiPc and NiTAA collaborate to reduce the *COOH formation energy barrier, favoring CO production in an acid electrolyte. It is a helpful route for designing outstanding conductive MCOF materials to enhance CO2 electrocatalysis under an acidic electrolyte.
ABSTRACT
The extensive utilization of rubber-related products can lead to a substantial release of p-phenylenediamine (PPD) antioxidants into the environment. In recent years, studies mainly focus on the pollution characteristics and health risks of PM2.5-bound PPDs. This study presents long-time scale data of PPDs and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) in PM2.5 and proposes the innovative use of PPDs as new markers for vehicular emissions in the Positive Matrix Factorization (PMF) source apportionment. The results indicate that PPDs and 6PPD-Q were detectable in 100 % of the winter PM2.5 samples, and the concentration ranges of PPDs and 6PPD-Q are 15.6-2.92 × 103 pg·m-3 and 3.90-27.4 pg·m-3, respectively, in which 6PPD and DNPD are the main compounds. Moreover, a competitive formation mechanism between sulfate, nitrate, ammonium (SNA) and 6PPD-Q was observed. The source apportionment results show that the incorporation of PPDs in PMF reduced the contribution of traffic source to PM2.5 from 13.5 % to 9.5 %. In the traffic source factor profiles, the load of IPPD, CPPD, DPPD, DNPD and 6PPD reaches 91.8 %, 91.6 %, 92.9 %, 80.6 % and 87.2 %, respectively. It`s amazing that traditional markers of traffic source, which often overlap with coal burning and industrial sources, over-estimated the contribution of vehicles by one third or more. The discovery of PPDs as specific markers for vehicular emissions holds significant utility, particularly considering the growing proportion of new energy vehicles in the future. The results may prove more accurate policy implications for pollution control. SYNOPSIS: PPDs are excellent indicators of vehicle emissions, and PMF without PPDs over-estimated the contribution of traffic source to PM2.5.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
Subject(s)
Animal Shells , Lipid Metabolism , Penaeidae , White spot syndrome virus 1 , Animals , Penaeidae/virology , Penaeidae/metabolism , Animal Shells/metabolism , Animal Shells/virology , White spot syndrome virus 1/physiology , Lipid Metabolism/physiology , Host-Pathogen Interactions , Lipogenesis/physiologyABSTRACT
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 1â g of donor stool per 1â 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 24â 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.
ABSTRACT
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.
Subject(s)
Lakes , Water Quality , China , Linear Models , Environmental Monitoring/methods , Water Pollutants, Chemical/analysisABSTRACT
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 OâO 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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.