Transition metal (TM)‐based bimetallic spinel oxides can efficiently activate peroxymonosulfate (PMS) presumably attributed to enhanced electron transfer between TMs, but the existing model cannot ...fully explain the efficient TM redox cycling. Here, we discover a critical role of TM−O covalency in governing the intrinsic catalytic activity of Co3−xMnxO4 spinel oxides. Experimental and theoretical analysis reveals that the Co sites significantly raises the Mn valence and enlarges Mn−O covalency in octahedral configuration, thereby lowering the charge transfer energy to favor MnOh–PMS interaction. With appropriate MnIV/MnIII ratio to balance PMS adsorption and MnIV reduction, the Co1.1Mn1.9O4 exhibits remarkable catalytic activities for PMS activation and pollutant degradation, outperforming all the reported TM spinel oxides. The improved understandings on the origins of spinel oxides activity for PMS activation may inspire the development of more active and robust metal oxide catalysts.
The Mn−O covalency was enlarged by the Co sites mainly in the octahedral configuration, which results in a decreased charge transfer energy to favor Mn–PMS interaction and enhance MnIV reduction to boost PMS activation activity of Co‐Mn spinel oxides.
1,2‐Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)‐catalyzed asymmetric ...hydrophosphination of α,β‐unsaturated phosphine sulfides was developed with the assistance of “soft–soft” interaction between copper(I)‐catalyst and the phosphine sulfide moiety, which afforded 1,2‐bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo‐ and enantioselectivities. Interestingly, the nucleophilic copper(I)‐diphenylphosphide species was characterized by 31P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2‐bisphosphines, which were employed as ligands in Rh‐catalyzed asymmetric hydrogenation of α‐amino‐α,β‐unsaturated ester. The α‐amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.
A catalytic asymmetric conjugate hydrophosphination of α,β‐unsaturated phosphine sulfides with diarylphosphines allows rapid construction of chiral 1,2‐bisphosphine derivatives with diversified electronic nature and steric hindrance. This reaction is facilitated by the “soft–soft” interaction between copper(I) catalysts and phosphine sulfides.
An α‐difluoroalkylation of benzyl amines with trifluoromethylarenes is disclosed herein. This protocol is characterized by its operational simplicity, excellent chemoselectivity and broad scope—even ...with advanced synthetic intermediates—, thus offering a new entry point to medicinally‐relevant α‐difluoroalkylated amines from simple, yet readily accessible, precursors.
A highly modular technique that streamlines the synthesis of α‐difluoroalkylated amines from benzyl amines and trifluoromethylarenes has been developed. This protocol demonstrates remarkable operational simplicity, excellent chemoselectivity, and wide applicability, including with advanced synthetic intermediates, thus providing a novel pathway to access medicinally‐relevant α‐difluoroalkylated amines from readily available and simple precursors.
Lithium metal batteries (such as lithium–sulfur, lithium–air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next‐generation energy storage systems. ...However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short‐circuit and thermal runaway of the rechargeable batteries. Herein, a dual‐layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual‐layered feature with organic components (ROCO2Li and ROLi) on the top and abundant inorganic components (Li2CO3 and LiF) in the bottom. The dual‐layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode. This work demonstrates the concept of rational construction of dual‐layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes.
A dual‐layered film is obtained on a Li metal anode by spontaneous chemical reaction between lithium plates and fluoroethylene carbonate solvents. Such film can protect the Li metal anodes from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode.
Eusocial insects have evolved diverse particle‐use behaviors. A previous study reported that red imported fire ants, Solenopsis invicta Buren, deposited soil particles on substances treated with ...essential balm, a fire ant repellent. We hypothesized that S. invicta modifies inaccessible surfaces by covering them with soil particles to facilitate food search and transportation. Here, laboratory experiments were conducted to study the particle‐covering behavior of S. invicta in response to viscose surfaces or surfaces treated with essential balm or liquid paraffin in the presence of real food (sausage) or non‐food objects (acrylic plates). S. invicta workers deposited significantly more soil particles on these three types of treated surfaces than on untreated surfaces. In addition, significantly more particles were relocated on viscose and paraffin‐smeared surfaces in the presence of food than in the presence of non‐food objects. The particle‐covering behavior on viscose surfaces was also observed in the field. Interestingly, when no soil particles were available, ants searched and transported food on viscose surfaces only if the surfaces were artificially covered with sufficient quantities of soil particles but could not do so on viscose surfaces without soil particles or with insufficient quantities of soil particles. In addition, ants actively relocated particles to cover viscose surfaces if the transportation distance was within 200 mm, whereas significantly fewer particles were relocated at longer transportation distances (400 mm). Our study provides a novel example of particle use by fire ants during foraging.
Solenopsis invicta generally performed particle‐covering behavior in reacting to different types of surface where they were not able to walk. The particles placed on viscose surface contribute to food searching and transport by S. invicta workers. Long transport distance of particles negatively affected the covering behavior.
The molecular components of the postsynaptic density (PSD) in excitatory synapses of the brain are currently being investigated as one of the major etiologies of neurodevelopmental disorders such as ...schizophrenia (SCZ) and autism. Postsynaptic density protein-95 (PSD-95) is a major regulator of synaptic maturation by interacting, stabilizing and trafficking N-methyl-d-aspartic acid receptors (NMDARs) and α-amino-3-hydroxy-5-methyl-4-isox-azoleproprionic acid receptors (AMPARs) to the postsynaptic membrane. Recently, there has been overwhelming evidence that associates PSD-95 disruption with cognitive and learning deficits observed in SCZ and autism. For instance, recent genomic and sequencing studies of psychiatric patients highlight the aberrations at the PSD of glutamatergic synapses that include PSD-95 dysfunction. In animal studies, PSD-95 deficiency shows alterations in NMDA and AMPA-receptor composition and function in specific brain regions that may contribute to phenotypes observed in neuropsychiatric pathologies. In this review, we describe the role of PSD-95 as an essential scaffolding protein during synaptogenesis and neurodevelopment. More specifically, we discuss its interactions with NMDA receptor subunits that potentially affect glutamate transmission, and the formation of silent synapses during critical time points of neurodevelopment. Furthermore, we describe how PSD-95 may alter dendritic spine morphologies, thus regulating synaptic function that influences behavioral phenotypes in SCZ versus autism. Understanding the role of PSD-95 in the neuropathologies of SCZ and autism will give an insight of the cellular and molecular attributes in the disorders, thus providing treatment options in patients affected.
•PSD-95 mediates NMDA and AMPA receptor clustering and function.•Genetic implications of PSD-95 deficiency in schizophrenia•PSD-95 & NMDAR dysregulation in schizophrenia•PSD-95 regulates spine density involved in schizophrenia.•PSD-95 is associated with NMDAR dysregulation and spine change in autism.
A new fluorescent sensing platform based on ultrathin metal-organic framework (MOF) nanosheets (MnDMS) was prepared from the flexible ligand 2,2-dimethylsuccinate and Mn ions. The MnDMS nanoparticles ...can be obtained by simply ultrasonication of the MnDMS crystal, and then can be exfoliated into nanosheets by Li-intercalation method. The MnDMS nanosheets can be easily assembled with biological probes, leading to efficient fluorescence quenching of the fluorophore tagged ssDNA and microRNA (miRNA). By using a hybridization chain reaction (HCR) strategy, the fluorescence signal can be obviously amplified. A good linearity was obtained from 1 pM to 200 pM of target ssDNA, with a detection limit of 0.2 pM. The HCR/MnDMS system provides an effective way to monitor miRNA in living cells. Therefore, the MnDMS nanosheets can be used as a new kind of platform in biomedical sensing applications.
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•Ultra-thin metal-organic framework nanosheets (MnDMS) were successfully prepared.•The MnDMS nanosheets show efficient fluorescence quenching ability toward fluorophore tagged DNA or miRNA.•With a hybridization chain reaction (HCR) strategy, the target signal can be obviously amplified.•The HCR/MnDMS system provides a simple and sensitive way to monitor DNA or miRNA in living cells.
Lithium‐metal electrodes have undergone a comprehensive renaissance to meet the requirements of high‐energy‐density batteries due to their lowest electrode potential and the very high theoretical ...capacity. Unfortunately, the unstable interface between lithium and nonaqueous electrolyte induces dendritic Li and low Coulombic efficiency during repeated Li plating/stripping, which is one of the huge obstacles toward practical lithium‐metal batteries. Here, a composite mixed ionic/electronic conductor interphase (MCI) is formed on the surface of Li by in situ chemical reactions of a copper‐fluoride‐based solution and Li metal at room temperature. The as‐obtained MCI film acts like the armor of a soldier to protect the Li‐metal anode by its prioritized lithium storage, high ionic conductivity, and high Young's modulus. The armored MCI can effectively suppress Li‐dendrite growth and work effectively in LiNi0.5Co0.2Mn0.3O2/Li cells. The armored MCI presents fresh insights into the formation and regulation of the stable electrode–electrolyte interface and an effective strategy to protect Li‐metal anodes in working Li‐metal batteries.
A composite mixed ionic/electronic conductor interphase (MCI) is formed on the surface of lithium by in situ chemical reactions of copper‐fluoride‐based solution and Li metal at room temperature. The as‐obtained MCI film acts like the armor of a soldier to protect the Li‐metal anode by its prioritized lithium storage, high ionic conductivity, and high Young's modulus.
Elucidating the prefrontal cortical microcircuit has been challenging, given its role in multiple complex behaviors, including working memory, cognitive flexibility, attention, social interaction and ...emotional regulation. Additionally, previous methodological limitations made it difficult to parse out the contribution of certain neuronal subpopulations in refining cortical representations. However, growing evidence supports a fundamental role of fast-spiking parvalbumin (PV) GABAergic interneurons in regulating pyramidal neuron activity to drive appropriate behavioral responses. Further, their function is heavily diminished in the prefrontal cortex (PFC) in numerous psychiatric diseases, including schizophrenia and autism. Previous research has demonstrated the importance of the optimal balance of excitation and inhibition (E/I) in cortical circuits in maintaining the efficiency of cortical information processing. Although we are still unraveling the mechanisms of information representation in the PFC, the E/I balance seems to be crucial, as pharmacological, chemogenetic and optogenetic approaches for disrupting E/I balance induce impairments in a range of PFC-dependent behaviors. In this review, we will explore two key hypotheses. First, PV interneurons are powerful regulators of E/I balance in the PFC, and help optimize the representation and processing of supramodal information in PFC. Second, diminishing the function of PV interneurons is sufficient to generate an elaborate symptom sequelae corresponding to those observed in a range of psychiatric diseases. Then, using this framework, we will speculate on whether this circuitry could represent a platform for the development of therapeutic interventions in disorders of PFC function.
This review (with 145 refs.) summarizes the progress that has been made in the use of zeolitic imidazolate frameworks in chemical sensing and biosensing. Zeolitic imidazolate frameworks (ZIFs) are a ...type of porous material with zeolite topological structure that combine the advantages of zeolite and traditional metal–organic frameworks. Owing to the structural flexibility of ZIFs, their pore sizes and surface functionalization can be reasonably designed. Following an introduction into the field of metal–organic frameworks and the zeolitic imidazolate framework (ZIF) subclass, a first large section covers the various kinds and properties of ZIFs. The next large section covers electrochemical sensors and assays (with subsections on methods for gases, electrochemiluminescence, electrochemical biomolecules). This is followed by main sections on ZIF-based colorimetric and luminescent sensors, with subsections on sensors for metal ions and anions, for gases, and for organic biomolecules. The last section covers SERS-based assays. Several tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends.
Graphical abstract
In recent years, ZIFs and their composites have been widely used as probes in chemical sensing, and these probes have shown great advantages over other materials. This review describes the current progress on ZIFs toward electrochemical, luminescence, colorimetric, and SERS-based sensing applications, highlighting the different strategies for designing ZIFs and their composites and potential challenges in this field.
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