Chiral metal-organic frameworks,as a class of advanced chiral materials with highly tunable structures,exhibit promising applications in the fields of medicine,biology,optics and so on.Recently,significant progresses of chiral metal-organic frameworks have been achieved.However,with the interdisciplinary intersection and integration of relevant research and various fields,new challenges have emerged,such as the efficient synthesis of chiral ligands and chiral metal-organic frameworks,their stability in potential application scenarios,and the molecular-level mechanisms underlying their enantiose-lective applications.This review discusses the direct synthetic strategies of chiral metal-organic frameworks(direct synthesis based on chiral ligands,spontaneous resolution from achiral ligands,chiral template induction,and chiral defect engineering)as well as post-synthetic modification strategies(post-modification of metal ion nodes/organic ligands and post-modification of functional guests).Furthermore,this review summarizes the research advances of chiral metal-organic frameworks in en-antioselective sensing,enantiomers separation,asymmetric catalysis,and chiral optics in recent five years,and provides an outlook in the future development of this field.
Protein O-linked β-N-acetylglucosamine(O-GlcNAc)glycosylation is a highly dynamic and reversible mono-saccharide post-translational modification in eukaryotic cells,playing critical roles in cellular regulation.To date,more than 5,000 O-GlcNAc-modified proteins have been identified,distributed in the cytoplasm,nucleus,mitochondria,and mem-braneless subcellular compartments.O-GlcNAcylation is catalyzed by O-GlcNAc transferase(OGT),which installs a single N-acetylglucosamine moiety onto serine and threonine residues,whereas removal of the modification is mediated by O-GlcNAcase(OGA).Uridine diphosphate N-acetylglucosamine(UDP-GlcNAc),the end product of the hexosamine bio-synthetic pathway(HBP),serves as the sugar donor for this modification.This tightly coupled enzymatic cycle allows O-GlcNAcylation to act as a nutrient-and signal-responsive regulatory modification,linking metabolic state to protein func-tion.O-GlcNAcylation regulates a broad range of fundamental cellular processes,including gene transcription,chromatin remodeling,epigenetic regulation,protein-protein interactions,and diverse intracellular signaling pathways.Dysregulation of global or protein-specific O-GlcNAcylation has been linked to the development and progression of multiple human diseases,including cancer,diabetes,and neurodegenerative disorders.With continuous advances in analytical methodologies,particu-larly high-resolution mass spectrometry and enrichment strategies,an increasing number of O-GlcNAc modification sites have been identified,allowing the functional roles of target proteins and their specific modification sites to be examined in detail.However,the highly dynamic nature of O-GlcNAcylation implies that chemical or genetic methods targeting OGT or OGA often lead to widespread changes in O-GlcNAc levels across thousands of proteins.Such global alterations complicate the functional interpretation of site-specific modifications and make it challenging to determine the precise role of O-GlcNAc at individual protein sites.Increasing evidence suggests that targeted modulation of specific O-GlcNAc sites on individual proteins provides improved mechanistic insight and greater translational relevance than global modulation approaches.Therefore,developing tools and strategies that allow site-specific modulation of O-GlcNAcylation on individual proteins,without altering overall O-GlcNAc levels,is critical.This review summarizes recent advances in targeted protein O-GlcNAcylation,highlights emerging chemical biology tools and strategies,and discusses their potential to reveal site-specific O-GlcNAc functions and their relevance to human disease.
The blood-brain barrier(BBB)serves as a crucial physiological structure that maintains homeostasis within the central nervous system.While its highly selective permeability protects the brain from exogenous substances,it also hinders the delivery of therapeutic agents.The current understanding of the physiological functions of the BBB remains relatively limited,primarily due to the absence of reliable in vitro models capable of accurately replicating its complex architecture and functionality.In recent years,microfluidic technology has emerged as a pivotal platform for developing highly biomimetic BBB models,capitalizing on its distinctive advantages in microscale fluid manipulation,establishment of multicellular co-culture systems,and reconstruction of physiologically relevant microenvironments.This review systematically summarizes recent advances in microfluidic BBB-on-a-chip systems,with particular focus on three key aspects:chip design configurations,fluid driving mechanisms,and cellular source selection.In terms of chip architecture,the discussion encompasses various structural designs,including sandwich-structured design,parallel channel design,three-dimensional tubular design,and angi-ogenic design.Regarding fluid propulsion methods,the analysis covers both pump-driven systems and gravity-driven ap-proaches.The examination of cellular sources includes immortalized cell lines,primary cell isolates,and stem cell-derived endothelial populations.Furthermore,the review comprehensively outlines established methodologies for evaluating barrier integrity and function.These assessment techniques include measuring transendothelial electrical resistance,performing per-meability assays with molecular tracers,and analyzing the expression of tight junction proteins and specialized transporters.The review concludes by addressing the current challenges confronting microfluidic BBB technology and proposing strategic directions for future development.These perspectives include enhancing model biomimicry through the incorporation of addi-tional neurovascular unit components,promoting technical standardization to ensure experimental reproducibility and compa-rability,developing personalized diagnostic and therapeutic models through integration of patient-specific cells,and exploring innovative applications through synergistic combination with artificial intelligence technologies.This comprehensive analysis aims to provide valuable guidance for researchers working at the intersection of biomedical engineering,neuroscience,and pharmaceutical development.
Medium-sized ring(7-to 12-membered)compounds possess unique molecular structures and biological activities.Widely distributed in natural products and pharmaceutically active molecules,they hold an important position in the research of organic chemistry and medicinal chemistry.In addition,in the field of materials science,medium-sized ring compounds offer numerous possibilities for the efficient synthesis of novel functional materials by virtue of their distinctive electronic distribution and spatial configuration.However,due to unfavorable entropic and enthalpic factors,as well as high transannular strain and strong conformational flexibility,the synthesis of medium-sized ring compounds is plagued by problems such as tedious procedures,low yields and poor functional group compatibility,which severely restricts the exploration,development and application of such compounds.Therefore,it is imperative to develop efficient,economical and structurally diverse synthetic strategies for medium-sized ring compounds.In recent years,the construction of medium-sized ring compounds via radical cascade cyclization has achieved considerable progress.This strategy generates highly reactive intermediates through radical pathways to trigger multiple consecutive transformations and forge multiple chemical bonds in one step,thus enabling the efficient synthesis of medium-sized ring compounds.It boasts numerous advantages including concise procedures,green and high efficiency,excellent functional group compatibility,high atom economy,and unique regio-and stereoselectivity,thereby providing a variety of strategies for the construction,development and application of medium-sized ring compounds.This paper summarizes the recent research advances in the synthesis of nitrogen/oxygen-containing medium-sized heterocyclic compounds via the radical cascade cyclization strategy,with a focus on the following two aspects:(1)Separately summarizing the synthetic strategies for 7-membered,8-membered,and 9-to 12-membered ring compounds;(2)Focusing on the elaboration of the reaction mechanisms,substrate scopes and practical applications of representative reactions.This thesis aims to provide new synthetic insights for the construction of nitrogen/oxygen-containing medium-sized heterocyclic compounds through the radical cascade cyclization strategy and facilitate its applications in the fields of new drug research and development,chemical engineering,materials science and other related areas.
Zirconium-based metal-organic frameworks(Zr-MOFs)have attracted significant attention due to their remarka-ble chemical stability and highly tunable topological architectures.Post-synthetic ligand insertion engineering offers an im-portant functionalization strategy capable of achieving precise design and modulation of the structure and function of the resulting Zr-MOFs,at the molecular level.This review systematically summarizes recent advances of ligand insertion within Zr-MOFs,with a focus on two dominant approaches of ligand installation and ligand exchange.It outlines the evolution from early-stage pendant-group modifications to the recent development of sequential ligand installation,elucidating the mecha-nisms,applicable scopes,and performance enhancements of these methods in areas such as gas adsorption/separation and heterogeneous catalysis,etc.Special emphasis is placed on how sequential ligand installation enables precise and stepwise incorporation of functional linkers through pre-engineered structural vacancies,thereby allowing atomic-scale modulation of pore microenvironments and enabling function enhancement.Finally,future challenges and prospects in scalable synthesis,multifunctional integration,and practical applications are discussed,providing theoretical guidelines for the rational design of high-performance Zr-MOFs materials.
Nuclear-grade zirconium is a critical metallic material for nuclear power plants.It boasts a low neutron absorption cross-section and corrosion resistance that are far superior to those of ordinary commercial zirconium materials.With high economic value and vital strategic significance,it serves as a strategic reserve resource critical to national energy security.Consequently,the efficient and economical preparation and recovery of nuclear-grade zirconium have garnered increasing at-tention.Molten salt technology serves as a crucial pathway for the separation of zirconium and hafnium,the preparation of metallic zirconium,and the recycling of the used zirconium,offering advantages such as a simplified process and strong adapt-ability.This review outlines the key role of molten salts in the life cycle management of nuclear-grade zirconium,including the analysis and comparison of the application characteristics of different molten salt systems(fluoride,chloride,and fluorine-chloride mixed salt systems)in the preparation and recovery of metallic zirconium.In addition,it focuses on systematically sorting out and summarizing the electroreduction behavior of zirconium ions in molten salts,aiming to promote the green metallurgy and recycling of nuclear-grade zirconium.
The extremely abundant reservoir of uranium resources in seawater is regarded as an important strategic pathway for alleviating future uranium shortage and supporting the sustainable development of nuclear energy.However,the ultra-low concentration of uranium in seawater,the presence of complex coexisting ions,and severe biofouling pose significant chal-lenges to achieving efficient and selective uranium extraction.Covalent organic frameworks(COFs),a class of crystalline porous materials featuring tunable structures,well-defined pore channels,high specific surface areas,and excellent chemical stability,have demonstrated unique advantages in uranium extraction from seawater(UES)in recent years.This review sys-tematically summarizes the latest research progress on COFs-based materials for UES,with particular emphasis on their ap-plications and underlying mechanisms in adsorption,photocatalysis,and synergistic uranium extraction driven by external fields such as light and electricity.Strategies including functional group modification,skeleton and defect engineering,com-posites & heterojunctions,morphology control,donor-acceptor(D-A)structures,reaction-pathway regulation,etc.are dis-cussed to analyze key advances in enhancing uranium extraction capacity,selectivity,kinetic performance,and resistance to biofouling.Finally,the challenges faced by COF-based materials in terms of large-scale application,long-term stability,and cost control are discussed,and future design directions and development trends for high-performance materials for UES are proposed.This review provides a systematic reference and conceptual insights for the in-depth study and practical application of COF-based materials in the field of UES.
With the continuous development of agriculture and industry,nitrate(NO3-)pollution in water bodies worldwide remains a serious issue,characterized by decentralized distribution across multiple sites.The electrocatalytic nitrate reduction reaction(eNO3RR)technology enables the reduction of NO3-waste into ammonia(NH3)—a substance useful to humans—under ambient temperature and pressure.However,under near-neutral pH conditions that mimic actual aquatic environments,eNO3RR faces multiple bottlenecks,including limited proton supply,competition from hydrogen evolution side reactions,risks of nitrite(NO2-)accumulation,and insufficient catalyst lifespan.Metal-organic framework(MOF)materials,which have at-tracted significant attention recently,hold tremendous potential.Their tunable porous structures and well-defined active sites are conducive to improving NO3-reduction efficiency and selectivity.Remarkable progress has been made in this field:ad-vanced MOF-based materials have achieved an NH3 Faraday efficiency(FE)of nearly 99％,suppressed NO2-accumulation,and pushed the NH3 yield to＞23000 μg·h-1·mgcat-1.By constructing conductive composite structures and employing derivat-ization strategies,MOF-based materials can maintain a FE of＞90％and remain stable for over 10 h at industrial-level current densities(＞950 mA·cm-2).This review focuses on MOF-based electrocatalysts and systematically analyzes the mechanism of neutral eNO3RR.Leveraging the atomic-level designability of MOFs,strategies such as single-atom/cluster regulation,multi-metal synergy,conductive composites,and derivatization can precisely overcome the bottlenecks of proton supply,hydrogen evolution competition,and stability in neutral eNO3RR,enabling efficient conversion of pollutants to NH3.Nevertheless,sev-eral challenges remain before this goal is fully achieved:the dynamic identification of active centers during catalysis is not sufficiently clear and accurate,long-term stability in real water bodies needs verification,and issues such as large-scale syn-thesis urgently require solutions.
