Browse Articles

A Homoleptic Ga ₄ Radical Anion: Isolation, Characterization, and Reactivity

ABSTRACT We report the synthesis and characterization of a homoleptic Ga 4 radical anion ([Li + ]•[ 1 •− ]), prepared via a salt‐metathesis reaction between Cp*Ga (Cp* = pentamethylcyclopentadienyl) and [Li 2 (L)] (L = Me 2 Si(DipN) 2 ). Combined structural and computational analyses reveal a nearly planar geometry at the central gallium atom, with only minimal distortion toward a trigonal pyramidal geometry, and the unpaired spin density localized in its 4p orbital. Density functional theory (DFT) calculations elucidate the reaction mechanism for the formation of [Li + ]•[ 1 •− ], while N ‐heterocyclic carbene (NHC)‐trapping experiments led to the isolation of NHC‐stabilized digallyl digallenes ( 2a and 2b ) as well as a digallyl‐substituted gallium radical ( 3c ). Compound [Li + ]•[ 1 •− ] exhibits versatile gallium‐centered radical reactivity, including one‐electron oxidation with S 8 and facile E─E bond activation (E = S, Se, and I) toward PhS‐SPh, PhSe‐SePh, and I 2 .

Implementation and experimental validation of a hybrid intelligent sliding mode control strategy for induction motor drives

Zero‐Valent Nickel Stabilized in Surface‐Supported Metal–Organic Chains

ABSTRACT The stabilization of zero‐valent nickel Ni(0) centers in extended coordination networks remains a major challenge due to their pronounced reactivity and susceptibility to oxidation. Here, we demonstrate that linear coordination confinement within a surface‐supported metal–organic chain enables the stabilization of Ni(0) atoms on Ag(100). The symmetry of 9,10‐dicyanoanthracene (DCA), combined with substrate templating effects, directs the formation of an ordered linear Ni‐DCA coordination motif. Spectroscopic measurements provide unambiguous evidence for a formal Ni(0) oxidation state, representing a rare realization of a zero‐valent transition metal center within an extended, atomically defined system. The electronic structure is governed by hybridization between Ni 3d orbitals and the π‐system of DCA, resulting in an anisotropic electronic dispersion with predominantly one‐dimensional character. These results establish linear coordination as a strategy to stabilize reactive, low‐valent metal centers in surface‐supported metal–organic architectures.

Differences in midwifery practical competence during parturitional period based on possessing of Japanese ‘advanced midwives’ certification: A nationwide multicenter questionnaire survey

A Programmable and Printable Microbial Bioelectronic Sensor for Real‐Time and Targeted Pollutant Monitoring in Water

ABSTRACT Rapid detection of toxic trace contaminants is critical for global water security, yet routine monitoring relies on costly, time‐consuming laboratory analyses. Microbial sensors offer a promising alternative but suffer from limited specificity, insufficient stability, and slow kinetics. Herein, we report a programmable and printable microbial bioelectronic sensor that overcomes these bottlenecks through multi‐scale chemical design. Using 2,4‐dinitrotoluene as a model pollutant, we genetically reprogrammed the extracellular electron transfer pathway of Shewanella oneidensis by coupling specific pollutant recognition to inner‐membrane cytochrome expression, thereby enabling highly specific bioelectrical detection of target pollutants. For robust deployment, these sensing microbes were encapsulated into a dual‐network hydrogel sustained by reversible hydrogen bonding, ensuring structural resilience and biocompatibility. By 3D‐printing the biosensor into a biomimetic fractal architecture, we minimized mass transport resistance, achieving a response time of 5 min, a 24‐fold acceleration over conventional counterparts. The biosensor also exhibited a low detection limit of 6.75 µg L −1 and a broad dynamic range from 20.4 to 700.0 µg L −1 ( R 2 > 0.999). Crucially, the biosensor maintained high accuracy (relative error < 4.2%) in actual wastewaters. This work establishes that the multiscale chemical design of microbial bioelectronic sensors enables real‐time, targeted pollutant monitoring.

Mitigation of drought stress in lettuce (Lactuca sativa L.) through application of zinc-oxide nanoparticles and humic acid: evaluation of growth, physiological, and biochemical indicators

Bis‐ <i>S</i> ‐Glycosylation of Disulfides

ABSTRACT Carbohydrates play essential roles throughout biology, making them key targets in biological research and drug development. While multivalent presentation of carbohydrates is widely recognized as crucial for high‐affinity target binding (the glycoside cluster effect), most existing methods focus on installing one glycosidic bond and lack robust strategies for attaching multiple carbohydrate units to a functional group. Here we report a mild, operationally simple protocol for the direct, stereoselective bis‐ S ‐glycosylation of dialkyl disulfide bonds in an open‐flask aqueous solution. This transformation installs two unprotected glycosyl units onto disulfide bonds, affording fully unprotected S ‐linked glycopeptides. The reaction employs bench‐stable, readily accessible glycosyl sulfinates as donors and tert ‐butyl hydroperoxide ( t BuOOH) as oxidant, forging cysteine‐glycosyl linkages via a radical pathway. Mixed disulfides derived from thiols partook in this reaction as well, allowing installation of one sugar unit onto peptide backbones. We applied this method to synthesize glycosylated peptides with liver‐targeting capabilities and to generate sugar‐linked affibody‐radionuclide conjugates. DFT calculations informed the reaction design and rationalized the observed selectivity of this transformation.

Regional geographic gradients dominate the association between apparent temperature and fine-particulate air pollution across China’s Yangtze River Delta at 1 km resolution

Hierarchical Ordering Decouples the SHG–Birefringence–LIDT Trade‐Off in a Single‐Phase Mid‐Infrared Nonlinear Optical Crystal

ABSTRACT The pursuit of high‐performance infrared nonlinear optical crystals is perpetually constrained by the inherent trade‐offs among second‐harmonic generation (SHG) efficiency, laser‐induced damage threshold (LIDT), and birefringence for phase‐matching (PM). Traditional compositional engineering, which seeks new formulas, is fundamentally limited by a compound's intrinsic electronic structure. Here, we introduce a paradigm shift of performance optimization through hierarchical order editing within a fixed chemical composition. In the model compound [Hg 3 Se 2 ][ZnCl 4 ], we demonstrate tuning of its hierarchical order encompassing both rotational twinning and superstructure by adjusting synthetic conditions, which yields three distinct variants ( 1 – 3 ) from a single formula. Their optical properties evolve progressively from negligible SHG ( 1 ), to weak non‐PM SHG ( 2 ), and finally to strong PM SHG alongside the highest LIDT ( 3 ). We reveal that this tunability stems from the decoupled roles of different ordering parameters, twinning primarily governs the SHG coefficient and birefringence, while superstructural modulation dominantly influences the LIDT. This work establishes hierarchical order editing​ as a powerful and general strategy for property optimization, transcending the limitations of compositional design.

A spatial modelling framework for equitable and efficient elderly care facility allocation in urban China

Abstract Rapid population ageing in China has significantly intensified the demand for equitable and efficient allocation of elderly care facilities. However, local governments continue to rely on simplistic ratio-based indicators, while advanced GIS-based spatial accessibility models remain rarely adopted in practice, resulting in a persistent implementation gap between academic research and real-world planning. This study reviews four mainstream accessibility algorithms and identifies low-resolution elderly population data as the primary barrier hindering the production of reliable results from advanced models. To address the distinctive characteristics of Chinese urban areas—particularly low data resolution and inconsistent elderly density patterns across old and new districts—we propose an integrated assessment framework based on the High-Resolution Gaussian 2SFCA method. This framework enhances the spatial resolution of demand estimates, provides a more context-sensitive treatment of service thresholds, and generates policy-interpretable assessment outputs. Application in two contrasting urban districts of Hangzhou shows that, compared with conventional approaches, the framework is less affected by aggregation bias in dense built-up areas and better able to distinguish between bed shortages and excessive service radii in low-density zones. By generating high-resolution and visually interpretable outputs, the framework helps narrow the implementation gap between academic spatial modelling and practical decision-making, providing local governments in data-constrained settings with an effective tool to support the implementation of aging-in-place policies.

Beyond Canonical CO Oxidation: Structural and Evolutionary Insights Into a Non‐Canonical Carbon Monoxide Dehydrogenase

ABSTRACT Carbon monoxide dehydrogenases (CODHs) catalyse the reversible oxidation of CO to CO 2 and play central roles in microbial carbon metabolism. While well‐characterised CODHs from different phylogenetic backgrounds exhibit high bidirectional activity, the enigmatic clade B remains functionally uncharacterised. Here, we present the first structural and biochemical characterisation of a clade B CODH from Ruminococcus flavefaciens ( Rf CODH). It reveals striking divergence from canonical enzymes. A new anaerobic cryo‐EM workflow was developed, carried out entirely under anoxic conditions by manual blotting and plunge freezing. It resulted in a 2.53 Å Rf CODH structure. The structure adopts the typical CODH fold, but exhibits blocked gas channels, a compromised proton transfer pathway and disrupted cofactor coordination. This provides a structural rationale for Rf CODH's severely attenuated CO oxidation activity (13 mU/mg vs. 900 U/mg for the well‐studied Ch CODH‐II). EPR spectroscopy reveals unique oxidised C‐cluster states not previously characterised in CODHs. Mirror tree analysis hints to co‐evolution between clade B CODHs and associated ABC transporter substrate‐binding proteins, suggesting these enzymes function in metabolism of substrates imported via the ABC transporter module. All findings indicate evolutionary repurposing of the CODH scaffold for alternative physiological functions.

Al–Ca co-doped ZnO nanostructures for enhanced electrical and dielectric properties

Abstract In this work, Al (1%) and Ca (5%) co-doped ZnO (ACZO) nanopowders were successfully synthesized using a modified sol–gel method combined with supercritical ethanol drying followed by thermal annealing. X-ray diffraction confirmed that all samples crystallize in the hexagonal wurtzite structure, with a reduction of the crystallite size from 52 nm for pure ZnO to 29 nm for ACZO due to lattice distortion induced by co-doping. SEM and EDS analyses revealed a porous morphology and a homogeneous distribution of Al and Ca within the ZnO matrix. Electrical measurements showed a clear thermally activated semiconducting behaviour, with conductivity following Jonscher’s universal power law and improved charge transport in the co-doped sample compared to undoped ZnO. The activation energy extracted from DC conductivity (112 ± 5 meV) and from modulus relaxation (96 ± 5 meV) are very close, confirming that both conduction and relaxation arise from the same hopping mechanism of localized charge carriers. Impedance, Nyquist, dielectric and modulus analyses all demonstrate that Al–Ca co-doping reduces grain boundary resistance, enhances carrier mobility, and improves dielectric response. These results highlight the effectiveness of dual doping in tuning the structural and electrical properties of ZnO for potential applications in electronic, sensing, and energy devices.

Processable Inverse‐Vulcanized Polymers With Silicon‐Like High Refractive Index and Transmittance for Infrared Optics

ABSTRACT Polymers prepared by inverse vulcanization have demonstrated overwhelming superiority over traditional organic materials for application as infrared optical materials. It is however still a great challenge to achieve suitable refractive index ( n ) and infrared transparency for all‐organic polymers, in contrast to inorganic optical materials. Herein, poly(S‐TTF) polymers with controlled sulfur feeding ratio were constructed by inverse vulcanizing tetrathiafulvalene (TTF, a very sulfur‐rich monomer). The resulting poly(S‐TTF) possessed large polarizability, multiple reaction sites, and high symmetry that endow the polymers with increased infrared refraction and transmission. Together with remarkable stability, lightweight and good processability in imprint lithography, the poly(S60‐TTF) with 88wt% sulfur content exhibits a competitive and tunable refractive index (∼3.0) and transmittances of &gt;60% in near and mid‐infrared regions by a millimeter‐level optical window. An ideal transmittance of visible light ( T Vis &lt; 2%) and near infrared ( T NIR &gt; 90%) was also realized for poly(S60‐TTF) films with 5µm thickness. Our strategy not only yields organic copolymers with competitive refractive index and exclusive infrared transmittance over inorganic materials for imaging and security applications, but also provides a valuable reference for balancing optical properties of inversed‐vulcanized polymers using sulfur‐ultrarich monomers.

Association of LILRA3 gene variants with central nervous system demyelinating syndromes of autoimmune origin in patients with late disease onset

Force‐Induced Control of Circularly Polarized Luminescence With Rotaxane Architecture

ABSTRACT The reversible molecular motions of mechanically interlocked molecules (MIMs) have played a crucial role in realizing stimuli‐responsive functions. While the reversible switching of circularly polarized luminescence (CPL) properties has been achieved using MIMs through pH change and/or addition of chemicals, the mechanically controlled CPL utilizing the interlocked architecture has not yet been demonstrated. Here, we introduce a rotaxane‐based mechanophore designed for force‐induced CPL on/off switching. The mechanophore consists of a ring featuring a CPL‐active helicene luminophore and an axle with a matching quencher. The rotaxane mechanophores covalently introduced at the cross‐linking points of a double‐network (DN) gel are reversibly activated and deactivated in response to changes in applied force transduced through the polymer chains during the macroscopic swelling and shrinking of the DN gel. The isotropic swelling of the DN gel effectively suppresses artifacts arising from macroscopic sample orientation, enabling accurate detection of reciprocal CPL derived from a single chiral emitter. This work establishes the first example of mechanical control of CPL at the single‐molecule level and provides a robust measurement methodology for force‐induced CPL switching in soft materials.

Multicenter retrospective study of offline reinforcement learning for insulin dosing during parenteral to enteral nutrition transition in ICU patients

Mimicking Enzyme Activation Within an Ionic Liquid‐Immobilized Coordination Capsules for Electroreduction of N ₂ to NH ₃

ABSTRACT Electrochemical nitrogen reduction powered by renewable electricity plays a crucial role in sustainable and eco‐friendly ammonia (NH 3 ), but current techniques were still limited by the low efficiency and selectivity for practical application. In this study, we introduce an enzyme‐inspired approach that utilizes a redox‐reversible helical capsule H1 to interact with the well‐modified N 2 ‐adducts for thorough electrochemical reduction of N 2 into NH 3 . The strategy included the utilizing of hydroxyl groups that decorated on the capsule to encapsulate the N 2 ‐associated ionic liquid to form a substrate‐involved intermediate, anodically shifting the redox potential of the N 2 adduct. The pocket shielding approach enables the production of NH 3 at a lower applied potential (−0.08 V vs. reversible hydrogen electrode, RHE) with enzymatic kinetics, facilitating a rate of 182.5 µg·mg −1 cat ·h −1 and a Faradaic efficiency of 48.50%, which is comparable to that of iron‐based native nitrogenase. A continuous working laboratory at 15 mA·cm −2 yields a NH 3 turnover number (TON) of 1640 over 100 h. The new strategy of molecular electrocatalysts with an enzymatic activation manner and anodic shift of the applied potentials sheds light on the rational design of high‐performance electro‐catalytic technologies for nitrogen capture and conversion.

Recent advances in selective and sensitive electrochemical spotting of toxic mercury (Hg+) and lithium (Li+) ions utilizing modified La-CdO/CdO electrode and its photocatalytic applications

More Than a Glow: How Cyanine Dyes Shape Tracer Pharmacokinetics

ABSTRACT Fluorescence molecular imaging stands as a crucial method for tracking physiological or pathological biomarkers within living organisms. In clinical practice, this technology is increasingly applied to assist physicians in decision‐making during interventional or surgical procedures. To develop imaging tracers, targeting molecules are covalently labeled with fluorescent organic dyes. Yet, it is often overlooked that such modifications to the molecule can influence and even alter its pharmacokinetics and distribution within the body. This review aims to provide an overview of the advancements in fluorophores commonly used in translational and clinical fluorescence molecular imaging, with a specific focus on long‐wavelength cyanine dyes. Additionally, we will illustrate how the fluorophore's structure and labeling parameters influence the in vivo behavior of molecules, underscoring the importance of considering these aspects when designing fluorescent tracers.

Construction of Axially Chiral Polymers by Asymmetric C–H Activation Polymerization

ABSTRACT Chiral polymers hold great potential in biomimics and synthetic materials, owing to their unique properties associated with diverse forms of chirality. Although polymers with central chirality are well‐developed, axially chiral polymers remain underexplored, presumably due to the lack of efficient synthetic methods. Herein, we develop a new strategy of asymmetric C–H activation polymerization for constructing axially chiral side chain polymers from prochiral monomers. Based on sequential Co‐catalyzed C–H activation/annulation, the polymerization proceeds in a quantitative manner, affording a range of axially chiral side chain polymers with high molecular weights, diverse chemical structures and tunable chiroptical properties. Furthermore, by stereochemical analysis of carefully designed model reactions, we have unambiguously confirmed excellent atroposelectivity control over the polymerization. This efficient strategy, which represents a significant advance in polymer synthesis, could open up new avenues for the design of chiral polymer materials with desirable properties.