Colony-stimulating factor 3 and its receptor promote leukocyte immunoglobulin-like receptor B2 expression and ligands in gastric

BACKGROUND Colony-stimulating factor 3(CSF3)and its receptor(CSF3R)are known to promote gastric cancer(GC)growth and metastasis.However,their effects on the immune microenvironment remain unclear.Our analysis indicated a potential link between CSF3R expression and the immunosuppressive receptor leukocyte immunoglobulin-like receptor B2(LILRB2)in GC.We hypothesized that CSF3/CSF3R may regulate LILRB2 and its ligands,angiopoietin-like protein 2(ANGPTL2)and human leukocyte antigen-G(HLA-G),contributing to immunosuppression.AIM To investigate the relationship between CSF3/CSF3R and LILRB2,as well as its ligands ANGPTL2 and HLA-G,in GC.METHODS Transcriptome sequencing data from The Cancer Genome Atlas were analyzed,stratifying patients by CSF3R expression.Differentially expressed genes and immune checkpoints were evaluated.Immunohistochemistry(IHC)was performed on GC tissues.Correlation analyses of CSF3R,LILRB2,ANGPTL2,and HLA-G were conducted using The Cancer Genome Atlas data and IHC results.GC cells were treated with CSF3,and expression levels of LILRB2,ANGPTL2,and HLA-G were measured by quantitative reverse transcriptase-polymerase chain reaction and western blotting.RESULTS Among 122 upregulated genes in high CSF3R expression groups,LILRB2 showed the most significant increase.IHC results indicated high expression of LILRB2(63.0%),ANGPTL2(56.5%),and HLA-G(73.9%)in GC tissues.Strong positive correlations existed between CSF3R and LILRB2,ANGPTL2,and HLA-G mRNA levels(P<0.001).IHC confirmed positive correlations between CSF3R and LILRB2(P<0.001),and HLA-G(P=0.010),but not ANGPTL2(P>0.05).CSF3 increased LILRB2,ANGPTL2,and HLA-G expression in GC cells.Heterogeneous nuclear ribonucleoprotein H1 modulation significantly altered their expression,impacting CSF3’s regulatory effects.CONCLUSION The CSF3/CSF3R pathway may contribute to immunosuppression in GC by upregulating LILRB2 and its ligands,with heterogeneous nuclear ribonucleoprotein H1 playing a regulatory role.

Study on the Fluid-Solid Coupling Seepage of the Deep Tight Reservoir Based on 3D Digital Core Modeling

Deep tight reservoirs exhibit complex stress and seepage fields due to varying pore structures,thus the seepage characteristics are significant for enhancing oil production.This study conducted triaxial compression and permeability tests to investigate the mechanical and seepage properties of tight sandstone.A digital core of tight sandstone was built using Computed Tomography(CT)scanning,which was divided into matrix and pore phases by a pore equivalent diameter threshold.A fluid-solid coupling model was established to investigate the seepage characteristics at micro-scale.The results showed that increasing the confining pressure decreased porosity,permeability,and flow velocity,with the pore phase becoming the dominant seepage channel.Cracks and large pores closed first under increasing pressure,resulted in a steep drop in permeability.However,permeability slightly decreased under high confining pressure,which followed a first-order exponential function.Flow velocity increased with seepage pressure.And the damage mainly occurred in stress-concentration regions under low seepage pressure.Seepage behavior followed linear Darcy flow,the damage emerged at seepage entrances under high pressure,which decreased rock elastic modulus and significantly increased permeability.

Differential Expressed Genes in ECV304 Endothelial-Like Cells Infected with Herpes Simplex Virus Type 2

Herpes simplex virus (HSV), the viral agent causing human genital herpes, recurs easily and poses significant harm to patients, while also being associated with atherosclerosis (AS). Currently, no effective therapy or vaccine exists to combat HSV. Previous studies have demonstrated the presence of HSV and its DNA in AS-diseased tissue, yet the precise pathogenesis of HSV involvement remains unclear. To investigate the genetic mechanism of HSV-induced vascular endothelial injury and AS, a type of human umbilical vein endothelial cells (ECV-304 cells) cultured in vitro were infected with herpes simplex virus type 2 (HSV-2). The effect of HSV-2 on differential gene expression in ECV304 cells was investigated by gene microarray technology during the early stages of infection. The results revealed a total of 462 differentially expressed genes, with 318 genes exhibiting up-regulated expression and 144 genes showing down-regulated expression. Furthermore, bioinformatics analysis revealed that all 462 differentially expressed genes were implicated in 237 distinct biological processes. Notably, 79 of these biological processes demonstrated statistically significant differences (P < 0.05), encompassing critical functions such as protein synthesis, ribosome biogenesis and assembly, as well as DNA and mRNA metabolism. Our findings have unveiled the differentially expressed genes of HSV-2 in ECV304 cells during infection, offering crucial insights into the pathogenic mechanisms underlying HSV-2 invasion of endothelial cells and the pathobiology of AS.

教学型公共仪器平台建设与开放机制探索

南京大学自2009年开始进行“三三制”本科教学改革,化学实验教学也按照此理念不断进行实验教学改革,以培养学生扎实的专业实践能力和良好的交叉跨界能力,提升学生的综合实践能力和创新实践能力。仪器设备在改革过程中起着重要的支撑作用,为了满足各实验课程的教学需求,化学国家级实验教学示范中心以培养“四个实践能力”为抓手,高质量建设了以教学为主的公共仪器平台。然而,仪器的开放共享也是资源优化利用的一项重要任务,如何在教学任务之余兼顾对外开放,需要进行不断的探索。本文以化学实验教学中心公共仪器平台为例,介绍平台在实验教学、使用培训、共享开放等方面所采取的管理机制,以及在此基础上取得的一些成果,供国内高校类似的仪器平台参考。

化学功能分子实验课程思政的探索与实践——以手性Mn(III)Cl-Salen配合物的合成及其催化性能研究实验为例

在化学功能分子实验课程教学过程中,对项目研究型实验——手性Mn(III)Cl-Salen配合物的合成及其催化性能研究实验蕴含的思政元素进行挖掘和融合,建设思政案例库。同时结合小组研究、科学汇报等多环节实验教学,开展全过程专业课程思政,丰富教学育人内涵,实现化学功能分子实验课程知识传授、能力提升和思政育人的三重功能。

Jianpi Gushen Huayu decoction ameliorated diabetic nephropathy through modulating metabolites in kidney,and inhibiting TLR4/NF-κB/NLRP3 and JNK/P38 pathways

BACKGROUND Jianpi Gushen Huayu Decoction(JPGS)has been used to clinically treat diabetic nephropathy(DN)for many years.However,the protective mechanism of JPGS in treating DN remains unclear.AIM To evaluate the therapeutic effects and the possible mechanism of JPGS on DN.METHODS We first evaluated the therapeutic potential of JPGS on a DN mouse model.We then investigated the effect of JPGS on the renal metabolite levels of DN mice using non-targeted metabolomics.Furthermore,we examined the effects of JPGS on c-Jun N-terminal kinase(JNK)/P38-mediated apoptosis and the inflammatory responses mediated by toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)/NOD-like receptor family pyrin domain containing 3(NLRP3).RESULTS The ameliorative effects of JPGS on DN mice included the alleviation of renal injury and the control of inflammation and oxidative stress.Untargeted metabolomic analysis revealed that JPGS altered the metabolites of the kidneys in DN mice.A total of 51 differential metabolites were screened.Pathway analysis results indicated that nine pathways significantly changed between the control and model groups,while six pathways significantly altered between the model and JPGS groups.Pathways related to cysteine and methionine metabolism;alanine,tryptophan metabolism;aspartate and glutamate metabolism;and riboflavin metabolism were identified as the key pathways through which JPGS affects DN.Further experimental validation showed that JPGS treatment reduced the expression of TLR4/NF-κB/NLRP3 pathways and JNK/P38 pathway-mediated apoptosis related factors.CONCLUSION JPGS could markedly treat mice with streptozotocin(STZ)-induced DN,which is possibly related to the regulation of several metabolic pathways found in kidneys.Furthermore,JPGS could improve kidney inflammatory responses and ameliorate kidney injuries in DN mice via the TLR4/NF-κB/NLRP3 pathway and inhibit JNK/P38 pathwaymediated apoptosis in DN mice.

Two stages power generation test of the hot dry rock exploration and production demonstration project in the Gonghe Basin,northeastern Qinghai-Tibet plateau,China

The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.

Enhancing the stability of Ni Fe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping

Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.

Ensuring Secure Platooning of Constrained Intelligent and Connected Vehicles Against Byzantine Attacks:A Distributed MPC Framework

This study investigates resilient platoon control for constrained intelligent and connected vehicles(ICVs)against F-local Byzantine attacks.We introduce a resilient distributed model-predictive platooning control framework for such ICVs.This framework seamlessly integrates the predesigned optimal control with distributed model predictive control(DMPC)optimization and introduces a unique distributed attack detector to ensure the reliability of the transmitted information among vehicles.Notably,our strategy uses previously broadcasted information and a specialized convex set,termed the“resilience set”,to identify unreliable data.This approach significantly eases graph robustness prerequisites,requiring only an(F+1)-robust graph,in contrast to the established mean sequence reduced algorithms,which require a minimum(2F+1)-robust graph.Additionally,we introduce a verification algorithm to restore trust in vehicles under minor attacks,further reducing communication network robustness.Our analysis demonstrates the recursive feasibility of the DMPC optimization.Furthermore,the proposed method achieves exceptional control performance by minimizing the discrepancies between the DMPC control inputs and predesigned platoon control inputs,while ensuring constraint compliance and cybersecurity.Simulation results verify the effectiveness of our theoretical findings.

Integrated ribosome and proteome analyses reveal insights into sevoflurane-induced long-term social behavior and cognitive dysfunctions through ADNP inhibition in neonatal mice

A growing number of studies have demonstrated that repeated exposure to sevoflurane during development results in persistent social abnormalities and cognitive impairment.Davunetide,an active fragment of the activity-dependent neuroprotective protein(ADNP),has been implicated in social and cognitive protection.However,the potential of davunetide to attenuate social deficits following sevoflurane exposure and the underlying developmental mechanisms remain poorly understood.In this study,ribosome and proteome profiles were analyzed to investigate the molecular basis of sevoflurane-induced social deficits in neonatal mice.The neuropathological basis was also explored using Golgi staining,morphological analysis,western blotting,electrophysiological analysis,and behavioral analysis.Results indicated that ADNP was significantly down-regulated following developmental exposure to sevoflurane.In adulthood,anterior cingulate cortex(ACC)neurons exposed to sevoflurane exhibited a decrease in dendrite number,total dendrite length,and spine density.Furthermore,the expression levels of Homer,PSD95,synaptophysin,and vglut2 were significantly reduced in the sevoflurane group.Patch-clamp recordings indicated reductions in both the frequency and amplitude of miniature excitatory postsynaptic currents(mEPSCs).Notably,davunetide significantly ameliorated the synaptic defects,social behavior deficits,and cognitive impairments induced by sevoflurane.Mechanistic analysis revealed that loss of ADNP led to dysregulation of Ca^(2+)activity via the Wnt/β-catenin signaling,resulting in decreased expression of synaptic proteins.Suppression of Wnt signaling was restored in the davunetide-treated group.Thus,ADNP was identified as a promising therapeutic target for the prevention and treatment of neurodevelopmental toxicity caused by general anesthetics.This study provides important insights into the mechanisms underlying social and cognitive disturbances caused by sevoflurane exposure in neonatal mice and elucidates the regulatory pathways involved.

Research on a Monte Carlo global variance reduction method based on an automatic importance sampling method

Global variance reduction is a bottleneck in Monte Carlo shielding calculations.The global variance reduction problem requires that the statistical error of the entire space is uniform.This study proposed a grid-AIS method for the global variance reduction problem based on the AIS method,which was implemented in the Monte Carlo program MCShield.The proposed method was validated using the VENUS-Ⅲ international benchmark problem and a self-shielding calculation example.The results from the VENUS-Ⅲ benchmark problem showed that the grid-AIS method achieved a significant reduction in the variance of the statistical errors of the MESH grids,decreasing from 1.08×10^(-2) to 3.84×10^(-3),representing a 64.00% reduction.This demonstrates that the grid-AIS method is effective in addressing global issues.The results of the selfshielding calculation demonstrate that the grid-AIS method produced accurate computational results.Moreover,the grid-AIS method exhibited a computational efficiency approximately one order of magnitude higher than that of the AIS method and approximately two orders of magnitude higher than that of the conventional Monte Carlo method.

Ocular surface changes in moderate-to-severe acne vulgaris

AIM:To investigate ocular surface disorders and tear function changes in patients with acne vulgaris and explore the potential relationship between acne vulgaris and dry eye.METHODS:This cross-sectional study included right eyes of 53 patients with acne vulgaris and 54 healthy controls.The participants completed the Ocular Surface Disease Index(OSDI)questionnaire.The following ocular surface-related parameters were measured:tear meniscus height(TMH),noninvasive tear breakup time(NIBUT),Schirmer I test(SIT),lipid layer thickness(LLT)score of the tear film,meibum score,meibomian gland orifice obstruction score,the ratio of meibomian gland loss,conjunctival hyperemia score,and corneal fluorescein staining(CFS)score.RESULTS:The stability of the tear film decreased in acne vulgaris patients.In the acne group,the TMH and NIBUT were lower,whereas the OSDI,meibum score,meibomian gland orifice obstruction score,ratio of meibomian gland loss,and conjunctival hyperemia score were higher compared with controls(P<0.05).There were no significant differences in the CFS score,SIT,or LLT score between the groups(P>0.05).In two dry eye groups,the TMH,NIBUT,and LLT score were lower in the acne with dry eye(acne-DE)group,and the meibum score,meibomian gland orifice obstruction score,ratio of meibomian gland loss and conjunctival hyperemia score in the acne-DE group were higher(P<0.05).There were no significant differences between OSDI,SIT,and CFS score(P>0.05).CONCLUSION:Patients with moderate-to-severe acne vulgaris are more likely to experience dry eye than those without acne vulgaris.Reduced tear film stability and meibomian gland structure dysfunction are more pronounced in patients with moderate-to-severe acne and dry eye.

Combined transarterial chemoembolization and tislelizumab for patients with unresectable hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)often presents as unresectable,necessitating effective treatment modalities.Combining transarterial chemoembolization(TACE)with immunotherapy and targeted therapy has shown promise,yet real-world evidence is needed.AIM To investigate effectiveness and safety of TACE with tislelizumab±targeted therapy for unresectable HCC in real-world setting.METHODS This retrospective study included patients with unresectable HCC receiving combined treatment of TACE and tislelizumab.The clinical outcomes included progression-free survival(PFS),overall survival(OS),objective response rate(ORR),and disease control rate(DCR).All patients were evaluated according to the mRECIST criteria.The adverse event(AE)was also assessed.RESULTS In this study of 56 patients with median follow-up of 10.9 months,7 had previous immunotherapy.Tislelizumab was administered before TACE in 21(37.50%)and after in 35(62.50%)patients,with 91.07%receiving concurrent targeted therapy.Median PFS was 14.0(95%CI:7.0-18.00)months,and OS was 28(95%CI:2.94-53.05)months.Patients with prior immunotherapy had shorter PFS(6 vs.18 months,P=0.006).Overall ORR and DCR were 82.14%and 87.50%.Grade≥3 treatment-related AEs included increased alanine aminotransferase(8.93%),aspartate aminotransferase(10.71%),and total bilirubin(3.57%).CONCLUSION The combination of TACE and tislelizumab,with or without targeted therapy,demonstrated promising efficacy and safety in unresectable HCC,especially in immunotherapy-naive patients,warranting further prospective validation studies.

Analysis of the Reform of Ideological and Political Education in College English Curriculum from the Perspective of“Cultural Confidence”

With the rapid development of the education industry,higher requirements have been put forward for college English education and teaching,accelerating the pace of college English reform.Issues such as how to integrate knowledge transmission,language expression skill improvement,cultural element extraction,and ideological and political education,and present the role of curriculum education function have attracted attention.In the era of informatization,college students’thinking has undergone certain changes and gradually developed towards diversification.Therefore,universities should start from the perspective of cultural confidence,extract valuable ideological and political elements,and explore effective tourism ideological and political teaching methods.While helping college students enhance their cultural confidence,it is also beneficial for them to better inherit traditional Chinese culture.This article conducts an in-depth exploration of ideological and political education in college English courses from the perspective of“cultural confidence”and uses scientific and effective measures to solve the problems encountered,aiming to provide valuable guidelines for relevant researchers.

术中平板CT对急性前循环大血管闭塞血管内机械取栓术后颅内出血的预测价值

目的 探讨术中平板CT对急性前循环大血管闭塞患者机械取栓术后颅内出血的预测价值。方法 纳入2020年3月至2023年6月在蚌埠医科大学第二附属医院行机械取栓术的106例急性前循环大血管闭塞患者,均行术中平板CT扫描,记录CT值、高密度征和占位效应。根据术后是否发生颅内出血分成颅内出血组(29例)和无颅内出血组(77例),单因素和多因素Logistic回归分析筛查术后发生颅内出血的影响因素,绘制受试者工作特征(ROC)曲线,评估术中平板CT对术后颅内出血的预测效能。结果 Logistic回归分析显示,高血压是急性前循环大血管闭塞患者机械取栓术后不发生颅内出血的保护因素(OR=0.340,95%CI:0.123~0.941;P=0.038),入院时美国国立卫生研究院卒中量表评分高(OR=1.068,95%CI:1.010~1.129;P=0.021)以及术中平板CT高密度征(OR=9.942,95%CI:2.631~37.567;P=0.001)、占位效应(OR=23.564,95%CI:7.266~79.421;P=0.000)和CT值≥90 HU(OR=9.714,95%CI:1.982~47.605;P=0.005)是术后发生颅内出血的危险因素。ROC曲线显示,术中平板CT值≥90 HU、占位效应及二者联合预测术后颅内出血的曲线下面积分别为0.82(95%CI:0.734~0.889,P=0.000)、0.75(95%CI:0.661~0.833,P=0.000)和0.76(95%CI:0.668~0.838,P=0.000),灵敏度为75.86%、58.62%和58.62%,特异度为88.31%、92.21%和93.51%,尤以CT值≥90 HU的预测效能最高(t=48.777,P=0.000;t=43.681,P=0.000)。结论 急性前循环大血管闭塞患者机械取栓术中平板CT呈高密度征如CT值≥90 HU、占位效应可以预测颅内出血,且CT值≥90 HU的预测效能较高。

Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction

Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(<33 L/s in Case 4) is employed, the cuttings bed completely blocks the borehole near the step surface and causes a stuck pipe directly. If the flow rate increases to the “low flow rate” interval(33-35 L/s in Case 4), a smaller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the “high flow rate” interval(>35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than those of other tripping velocities. As long as the applied tripping velocity is not within the “dangerous velocity”(0.4-0.5 m/s in Case 5) interval in the backreaming operation, the risk of the stuck pipe can be controlled validly. Finally, through the factors analyses of the annular geometry,particle properties, and fluid properties in Section 5, it can be found that the “low flow rate”, “high flow rate” and “dangers flow rate” tend to decrease and the “dangerous velocity” tends to increase with the conditions more favorable for hole cleaning. This study has some guiding significance for risk prediction and parameter setting of the backreaming operation.

Amorphous core-shell NiMoP@CuNWs rod-like structure with hydrophilicity feature for efficient hydrogen production in neutral media

Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.

基于单原子铁催化剂的过一硫酸盐高级氧化过程: 配位结构和活性组分

随着全球工业化的迅速发展,大量有毒污染物不断排入水体中,对水生态系统和人类健康构成了严重威胁.为应对这一挑战,人们发展高级氧化技术,其通过产生活性自由基,能够氧化并矿化有毒污染物.其中,利用非均相催化剂活化的过一硫酸盐高级氧化过程可产生多种非自由基活性物种,如单线态氧、催化剂-过硫酸盐复合体和高价态金属,这些物种具有选择性氧化特定污染物的能力.为了实现对污染物的精准处理,需要合理设计与调控非均相催化剂的结构,以选择性地产生自由基/非自由基物种.单原子催化剂具有较高的原子利用效率和明确可调控的活性位点结构,可高效且选择性活化过一硫酸盐,并产生多种活性组分.然而,由于活性组分多元的生成路径及其之间复杂的相互作用,目前对于单原子催化剂在过一硫酸盐活化过程中的结构-活性/选择性关系尚未得到深入揭示.因此,本研究旨在通过深入探究单原子催化剂的结构与性能关系,为优化催化剂设计、提升污染物处理效率提供科学依据.本文围绕最具代表性的单原子铁系催化剂,系统分析并总结了在过一硫酸盐高级氧化过程中的结构-活性/选择性关系.首先,简要介绍了单原子铁催化剂的制备方法和表征手段,以及活性位点结构的生成过程.然后,深入分析了单原子铁催化剂活化过一硫酸盐过程的研究进展和反应特性.从理论与实验角度,详细阐述了过一硫酸盐活化过程中活性物种产生的反应原理.具体来说,探讨了自由基、单线态氧、催化剂-过硫酸盐复合体和高价铁组分在不同单原子铁位点上的生成机理及鉴别方法.进一步地,分析了单原子铁催化剂活性位点的几何结构和电子结构性质对活性物种产生的影响,总结了调控活性位点的有效手段.在此基础上,建立单原子铁催化剂结构与产生活性组分之间的结构-活性/选择性关系,以期为非均相过一硫酸盐活化剂的设计提供理论指导.最后,本文还指出了基于单原子催化剂的过一硫酸盐高级氧化过程所面临的挑战,并展望了未来的发展方向.未来,应进一步发展原位/工况条件下的表征技术,以精准捕捉活化过程中活性位点的结构演变和关键反应中间体的生成,从而更深入地揭示反应机理;此外,设计具有双金属位点的催化剂,可优化多步骤反应中不同反应中间体的吸附与电荷转移过程,实现协同催化效果.本文期望为深入理解过一硫酸盐高级氧化技术的反应机理和开发高效选择性的单原子环境催化剂提供有益借鉴.

Pore structure and oxygen content design of amorphous carbon toward a durable anode for potassium/sodium-ion batteries

Both sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)are considered as promising candidates in grid-level energy storage devices.Unfortunately,the larger ionic radii of K+and Na+induce poor diffusion kinetics and cycling stability of carbon anode materials.Pore structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration,increasing the transport channels,and alleviating the volume change.However,traditional pore-forming agent-assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon materials.Herein,porous carbon materials(Ca-PC/Na-PC/K-PC)with different pore structures have been prepared with gluconates as the precursors,and the amorphous structure,abundant micropores,and oxygen-doping active sites endow the Ca-PC anode with excellent potassium and sodium storage performance.For PIBs,the capacitive contribution ratio of Ca-PC is 82%at 5.0 mV s^(-1) due to the introduction of micropores and high oxygen-doping content,while a high reversible capacity of 121.4 mAh g^(-1) can be reached at 5 A g^(-1) after 2000 cycles.For SIBs,stable sodium storage capacity of 101.4 mAh g^(-1) can be achieved at 2 A g^(-1) after 8000 cycles with a very low decay rate of 0.65%for per cycle.This work may provide an avenue for the application of porous carbon materials in the energy storage field.