Browse Articles

J-shaped relationship between physical activity and frailty risk in adults with sleep disorders: the additional protective role of the weekend warrior pattern

Chiral Dysprosium Single‐Molecule Magnets Displaying Circular Polarized Luminescence and Magneto‐Chiral Dichroism

ABSTRACT The combination of single‐molecule magnet (SMM) behavior with chiroptical and magneto‐(chiro)optical properties allows for the preparation of functional materials responsive to light and magnetic fields. Herein, we report on novel enantiopure chiral lanthanide (Ln) SMMs derived from the [Ln(bbpen)] + scaffold (bbpen = N,N′‐bis(2‐hydroxybenzyl)‐N,N′‐bis(2‐methylpyridyl)ethylenediamine), formulated as [Dy(bbpen)((1 S ,2 S )/(1 R ,2 R )‐ chxn )](BPh 4 ) ( Dy‐ S / R ) ( chxn = 1,2‐diaminocyclohexane). These chiral complexes exhibit SMM behavior associated with effective energy barriers over 800 K and strong room‐temperature NCD and MCD responses, as evidenced by the g NCD and g MCD dissymmetry factors. CPL measurements at room temperature reveal | g lum | values of 0.23(2) for the 4 F 9/2 → 6 H 11/2 magnetic dipole‐allowed transition, setting a new record value in the realm of chiral SMMs. Furthermore, variable‐temperature and variable‐field MChD spectroscopy measurements reveal among the strongest magneto‐chiral optical responses reported so far for Dy III chiral complexes, despite the electric‐dipole induced nature of the Dy III f‐f electronic transitions. Dynamic MChD measurement at low temperature allowed us to optically trace the magnetic hysteresis cycles for both enantiomers and for different electronic transitions. Overall, this study establishes the bbpen scaffold as an ideal building block for the preparation of multifunctional materials and open great perspectives for the preparation of novel chiral materials with enhanced magneto‐(chiro)optical responses by chemical design.

Explainable attention-based neural network for load forecasting in super smart grids using socioeconomic and power consumption data

Jahn–Teller Effect Induces Exchange Bias in Ultrasmall Magnetite

ABSTRACT Exchange bias, a quantum phenomenon confined to macroscopic interfacial ferromagnetic‐antiferromagnetic heterostructures, has remained unobserved in superparamagnetic single‐phase 0‐dimensional (0D) nanosystems, where magnetic interfaces are absent. Here we demonstrate intrinsic exchange bias in freestanding magnetite (Fe 3 O 4 ) nanoparticles (4.0 nm), mediated by symmetry‐breaking Jahn–Teller‐type lattice distortions. Ångström‐scale symmetry‐lowering lattice displacements in octahedral Fe 2+ (3d6) modulate the local crystal field environment, induing a spin‐state reconfiguration from a low‐spin ( S  = 0) toward a high‐spin state ( S  = 1), accompanied by the breaking of magnetic space‐group and time‐reversal (𝒯) symmetries. The high‐spin state couples to 𝒯‐symmetric antiparallel Fe 3+ (3d5) spins via double exchange, bypassing conventional interfacial interactions. This work establishes Jahn–Teller driven symmetry breaking as a new mechanism for exchange bias in quantum‐confined systems, opening pathways for engineering emergent spin correlations in single‐phase 0D spintronic architectures with three‐dimensional nanoconfinement (nm × nm × nm scale).

Novel calculation methods for geometrically accurate thread depth

Abstract In advanced manufacturing systems, particularly High-Mix Low-Volume (HMLV) environments, achieving first-pass conformity in threaded components remains challenging due to strict ISO tolerance requirements, non-standardized tool geometries, and reliance on gauge-based iterative corrections. These limitations not only reduce machining accuracy but also increase setup time, energy consumption, and material waste. This study introduces three fundamentally new calculation methods that enable precise geometrical determination of thread depth for CNC turning and milling of both external and internal metric threads. The methods integrate ISO-defined pitch-diameter tolerances, detailed tool geometry, and measured nose radius into a unified analytical framework, thereby enabling automatic and dimensionally accurate G-code generation. Method 1 addresses external thread turning using full-profile inserts. Method 2 provides a generalized model for external thread milling with free-form radii. Method 3 extends the approach to internal threads by incorporating pre-machined reference diameters. Industrial case studies demonstrates that the proposed methods can enhance precision manufacturing, eliminate trial-and-error adjustments. The results contribute to advanced and green manufacturing practices by improving automation readiness, shortening machine setup cycles, and enabling reliable production of atypical thread sizes and tolerance classes.

Strain‐Sequenced Synthesis of a Quadruply Twisted Cycloarene With Alternating [4]/[5]Helicenes

ABSTRACT Topologically nontrivial molecular nanocarbons, such as cycloarenes with multiple helical twists, represent attractive targets that anticipate the cavity‐defined properties of classical cycloarenes with the topological complexity of strained helicene assemblies, which remain largely unexplored. Herein we report a strain‐sequenced synthesis of a quadruply twisted cycloarene consisting of alternating [4]/[5]helicenes along the π‐conjugated framework. The synthesis involved a rational macrocyclization of 1,1‐diaryl‐2,2‐diethynylethylene linkers with anthryl spacers, and an InCl 3 ‐catalyzed, eightfold alkyne benzannulation. Mechanistic studies reveal that the high intrinsic energy of the alkyne‐containing precursor drives a key C─C σ‐bond rearrangement through a spiro ‐five‐membered‐ring intermediate to deliver An4 with quadruple helical twists. X‐ray crystallography confirms the parallelogram geometry, featuring a well‐defined central cavity with distinct ‘Cove’ and ‘Fjord’ regions. Bond‐length analysis, complemented by theoretical calculations, revealed that both the modeling compound AnM and An4 undergo adaptive π‐electron redistribution to maximize the number of aromatic sextets, resulting in stable and locally aromatic ground states consistent with Clar's rule. The electronic structure is dominated by local aromaticity, with negligible global delocalization. This study not only introduces a versatile synthetic strategy for topological nanocarbons with multiple helical twists, but also provides fundamental insights into the interplay between strain, reactivity, and aromaticity in contorted π‐systems.

Author Correction: Continuous radon monitoring during seven years of volcanic unrest at Campi Flegrei caldera (Italy)

Ordered Ionic Nanochannels in Covalent Organic Frameworks for Photosynthesis of H ₂ O ₂ From Ambient Air‐Equilibrated Water

ABSTRACT Covalent organic frameworks (COFs) hold great promise for photosynthetic H 2 O 2 but suffer from limited water/oxygen transport dynamics and low electron utilization efficiency. Herein, we report efficient solar‐driven H 2 O 2 production directly from ambient air‐equilibrated water using ionic vinylene‐linked covalent organic frameworks (ivCOFs). Guided by electron donor‐acceptor (EDA) complexation, we synthesize highly crystalline ivCOFs with permanent porosity and well‐defined ionic nanochannels entirely in water. The resulting ivCOFs synergistically integrate ultrafast water transport and robust Pauling‐type O 2 adsorption. Notably, the embedded ionic groups modulate the electronic band structure, effectively suppressing the hydrogen evolution side reaction and enhancing both thermodynamic driving force and selectivity for the 2e − oxygen reduction to H 2 O 2 . Consequently, ivCOF‐I achieves a high H 2 O 2 production rate of 6.9 mmol g −1 h −1 , an apparent quantum yield of 15.7%, and a solar‐to‐chemical efficiency of 1.08%, all using only air and water. It operates stably in both batch and continuous‐flow systems (> 120 h), retaining structural integrity. Mechanistic studies confirm concurrent 2e − water oxidation and oxygen reduction pathways. This work underscores the pivotal role of EDA complexes in stabilizing ionic building blocks and offers a rational design paradigm for sustainable solar‐driven chemical production.

Biomechanical comparison of two-screw and four-screw zero-profile fusion devices in anterior cervical discectomy and fusion using finite element analysis

Single‐Site Nickel‐Anchored Photosensitive Covalent Organic Framework for Metallaphotocatalytic C─S/C─N Cross‐Coupling Reactions

ABSTRACT The development of multifunctionally heterogeneous catalysts, simultaneously bearing photosensitizer and nonnoble metal catalyst in close spatial proximity, represents a promising solution for promoting metallaphotoredox‐mediated catalysis, albeit it remains challenging. Herein, a single‐site Ni‐functionalized photosensitive covalent organic framework (COF), TTA‐BPyDA(Ni)‐COF, has been constructed by implementing a postsynthetic metallization strategy in a triazine‐based COF scaffold. The precise integration of photosensitizer and Ni‐catalytic active centers within TTA‐BPyDA(Ni)‐COF not only dramatically improves the metallaphotocatalytic (MPC) performance in C─S/C─N cross‐coupling reaction between diverse thiols/amines and aryl iodides with electron‐rich/neutral/deficient groups but also confers TTA‐BPyDA(Ni)‐COF with outstanding recyclability and durability compared with its homogeneous counterpart. Importantly, the MPC C─S/C─N reaction mechanisms have been well established by comprehensive experimental and theoretical simulations. This work offers valuable insights for developing single‐site nonnoble metal‐functionalized COF catalytic platforms that integrate photoredox centers with catalytic transition‐metal cores.

Quantitative measurement of stag beetle behaviors in low light and complex background conditions using DAMM (detect any mouse model)

Synergistic Chirality in Spiro‐Fused Chiral Conjugated Helices

ABSTRACT This study presents the design and synthesis of novel spiro‐fused chiral conjugated helices via a bilateral bent‐π‐extension strategy to elucidate chirality synergy across mixed chiral centers. Notably, six stereoisomers of SDPD6H , including three enantiomeric pairs, were successfully obtained and fully resolved. Single‐crystal structural analysis reveals that helicene fusion onto the spirodiperylenetetraimide ( SDP ) skeleton induces significant bending of the originally planar perylene diimide subunits into bowl‐shaped geometries, breaking molecular symmetry and thus raising the isomerization barrier. Furthermore, the stereoisomers exhibit distinct chiroptical responses, with P , S , P ‐ 6 showing the strongest chiroptical activity (Cotton effects: |Δ ε | reaching 310 M −1 cm −1 ). Through in‐depth theoretical analysis of rotatory strength ( R ), we elucidate the origin of the circular dichroism (CD) behavior in the 425–600 nm region. In homochiral bishelicene configurations ( P , P or M , M ), the magnetic transition dipole moments ( m ) from the two molecular fragments differ significantly in magnitude, leading to non‐canceling R 3 and R 4 , and thus pronounced CD signals. In contrast, heterochiral configurations ( P , M ) produce magnetic dipoles of similar magnitude but opposite sign, resulting in near‐complete cancellation and a suppressed CD response. This work provides a mechanistic understanding of stereochemical interplay in hybrid multi‐chiral‐centers systems and establishes a new design strategy for advanced chiroptical materials.

Structural assessment of Umm Lajj coastal area, Northwestern Saudi Arabia, using integrated aeromagnetic and gravity data: hydrogeological implications

Coupling Space Charge Storage With Alloying Reactions Anode for Ultrafast and High Energy Storage

ABSTRACT Achieving the dual objectives of high‐energy‐density and high‐power‐density within a single electrode has long been regarded as the “holy grail” for lithium‐ion batteries. Herein, a mixed electronic/ionic/alloy conductor material (Fe/Li 2 O‐Sn) is successfully developed to address this challenge by coupling the space charge storage mechanism with alloying reaction. The strong affinity and abundant interfaces between the metallic iron and the Li 2 O facilitates ultrafast lithium‐ion diffusion throughout the electrode. By the mixed electronic and ionic conducting networks, the alloying reaction of tin (Sn) not only demonstrates ultrafast reaction kinetics but also fully utilizes its high theoretical capacity. Benefiting from the unique structure, the Fe/Li 2 O‐Sn electrode delivers an outstanding electrochemical performance, including an ultrafast charging/discharging rate of 40 A g − 1 , a high‐energy‐density of 1242 Wh kg −1 , and an exceptional cycling ability of over 20,000 cycles. This synergistic integration of the space charge effect with alloying reactions in anode materials holds significant potential for the development of lithium‐ion batteries with high energy‐density, high power‐density and long‐term cycling stability.

Computational framework for multi-objective optimization of activated biochar properties using machine learning and evolutionary algorithms

Abstract Climate neutrality and renewable energy expansion demand multifunctional materials capable of simultaneous carbon sequestration and electrochemical energy storage. Agricultural residue biochar offers dual-function potential, yet conventional pyrolysis does not systematically optimize competing objectives. This study presents a simulation-based computational framework integrating multi-output random forest surrogate modeling with differential evolution algorithms to identify Pareto-optimal process configurations balancing specific surface area, CO 2 adsorption, electrochemical capacitance, and carbon stability. 800 parameter combinations were evaluated across pyrolysis temperature (400–900 °C), residence time (0.5–3.0 h), heating rate (5–50 °C min − 1 ), activation chemistry (KOH, $$\:{\text{H}}_{3}{\text{PO}}_{4}$$ , $$\:{\text{ZnCl}}_{2}$$ , NaOH), and five feedstock classes using calibrated response surfaces. The surrogate model achieved test-set $$\:{\text{R}}^{2}$$ of 0.971 (RMSE = 48.06 m 2 g − 1 for specific surface area and 0.942 (RMSE = 6.67 F g − 1 for specific capacitance on 160 independent samples; CO 2 adsorption yielded $$\:{\text{R}}^{2}$$ = 0.788, while carbon stability index showed moderate fidelity ( $$\:{\text{R}}^{2}$$ = 0.497, RMSE = 0.069), consistent with challenges in modeling recalcitrance from compositional proxies. Multi-objective optimization identified configurations with specific surface area of 1094 m 2 g − 1 , $$\:{\text{CO}}_{2}$$ adsorption of 5.01 mmol g − 1 , and specific capacitance of 114 F g −1 . Pyrolysis temperature was the dominant predictor (48% feature importance); hydrogen-to-carbon ratios below 0.4 demarcate recalcitrant materials suitable for millennial-scale sequestration. Optimized processing achieved feedstock-independent carbon stability (median 0.44–0.46) across all biomass types. Spatially explicit assessment indicates that EU-scale deployment could sequester 53.9 Mt $$\:{\text{CO}}_{2}$$ e year −1 , equivalent to 1.2% of total EU greenhouse gas emissions. Experimental validation of selected configurations constitutes the primary direction for future work.

Cationic Organic Polymers With Electrostatic Shielding Effect and Lithiophilic Sites for Dendrite‐Free Lithium Metal Batteries

ABSTRACT Uncontrolled lithium dendrite growth and persistent electrolyte breakdown present major safety challenges, limiting the practical deployment of lithium metal batteries (LMBs). In this study, a unique organic polymer (Ni‐HAT CN), rich in lithiophilic sites and cationic groups, is designed as a protective layer for lithium metal anodes (LMAs) to enable uniform lithium deposition and enhance Li + flux. On one hand, the positively charged Ni 2+ sites in the polymer modify the electronic structure and provide robust electrostatic shielding to suppress adverse side reactions. On the other hand, the dense lithiophilic sites (C═N, C≡N, etc.) in HAT CN facilitate Li + diffusion and accelerate the desolvation process of Li + . Furthermore, the in‐depth working mechanisms behind these effects are revealed through a variety of in situ/ex situ characterizations and theoretical calculations. As a result, the Li + transference number of the Ni‐HAT CN‐protected battery increases to 0.76, and it exhibits stable cycling for over 3000 h (3 mA cm −2 ). The full cell maintains high capacity after 900 stable cycles at 1 C, with an average ultra‐low degradation rate of just 0.047% per cycle. This work offers a novel strategy for stabilizing LMAs by uniquely combining electrostatic field construction with the regulation of solvation structures.

Precision detection of miniature dam cracks with a multi-scale enhanced YOLO framework for UAV inspection

Abstract Accurate detection of dam cracks from Unmanned Aerial Vehicle (UAV) imagery is crucial for structural health monitoring. However, prevailing methods face significant challenges in achieving a balance between the precise identification of minuscule cracks and computational efficiency when processing high-resolution images. To overcome these limitations, this paper proposes HiResDC-YOLO, a novel deep learning framework based on an enhanced YOLOv12 architecture. Our main contributions are threefold: First, we introduce an Adaptive Dynamic Transformer (ADyT) module to strengthen nonlinear feature representation and stabilize gradient flow during training. Then, we design a Multi-Scale Enhanced Detection (MSED) head that effectively utilizes shallow, high-resolution features to significantly improve the detection capability for fine cracks. Besides, we develop a Multi-Scale Convolutional Attention (MSCA) module to capture comprehensive contextual information across different scales by integrating deep convolutional layers and a multi-branch fusion mechanism. Furthermore, we propose a High-Resolution Adaptive Inference (HiResInfer) strategy, which utilizes region-guided slicing and feature caching to dramatically accelerate the inference speed on full-resolution images without compromising the integrity of small targets. Extensive experiments on a challenging self-collected UAV dam crack dataset demonstrate that HiResDC-YOLO achieves state-of-the-art performance, surpassing existing methods significantly in terms of precision, recall, and mean Average Precision (mAP), while maintaining high computational efficiency. This work presents a robust and practical solution for real-time dam inspection and engineering safety monitoring. The code and related resources are available at: https://github.com/lijin6/HiResInfer-YOLO.git .

Covalent Network Formation Rate Controls Depletion‐Induced Supramolecular Assembly in Hybrid Double Network Hydrogels

ABSTRACT The introduction of a secondary covalent polymer network is a powerful approach to extend the usable application range of supramolecular hydrogels. While it is recognized that dramatic changes in mechanics can occur with their addition, there is a lack of insight into the impact of added covalent polymers on hydrogels with underlying supramolecular filament nanostructures. Here we show that through controlling the rate of covalent network formation by the inverse electron‐demand Diels–Alder reaction, the mesoscale architecture of the supramolecular network can be programmed. Slow macromonomer crosslinking enables depletion‐induced supramolecular assembly of the supramolecular filaments into bundles above a critical macromonomer concentration, whereas rapid covalent network formation halts this dynamic process by effectively locking in the low‐nm scale supramolecular nanostructures. This kinetic difference further translates into mechanically distinct hydrogels, where slow‐forming hybrid networks reveal a two‐fold increase in toughness as compared to fast‐crosslinked networks, thanks to the bundled supramolecular filaments. Through harnessing the macromolecular crowding capacity of reactive macromonomers and their reaction kinetics, a new axis to control the hierarchical structure of supramolecular hydrogels through depletion forces is unlocked that can be exploited to shape this soft matter class for numerous applications.

Cortical activity and functional organisation during ocular pursuit is affected by concurrent upper limb movement

Abstract Tracking a moving object with the eyes involves sensory-motor and cognitive processes, and is supported by a wide network of cortical areas. We investigated if cortical activity and network organisation in young adults are influenced by the availability of retinal input when pursuing a moving object, and whether this is modulated by extra-retinal input from concurrent upper limb movement. As expected, we found a decrease in average eye velocity, and increase in saccadic displacement, when the moving object was occluded, as well as a general facilitatory effect of oculo-manual tracking. We also found decreased activity in prefrontal and frontal cortex during oculo-manual compared to ocular tracking when the moving object was occluded. Following a short period of practice in the oculo-manual condition without occlusion, there was an increase in activity in prefrontal, parietal and visual cortex during ocular tracking. These findings could indicate how extra-retinal input during oculo-manual tracking reduces the need for attentional and predictive processes to extrapolate and pursue the occluded object. This is an important step in better understanding impaired oculo-manual coordination (e.g., age-related decline), potentially informing the development of more effective tasks for differential diagnosis and rehabilitation.

Highly Reversible Aqueous Anode‐Free Cadmium–Bromine Batteries

ABSTRACT Aqueous anode‐free zinc (Zn)‐based batteries promise high energy density; however, their reversibility and lifespan are hampered by dendritic growth, hydrogen evolution, and poor Zn utilization (<20%). Cadmium (Cd), a close analogue of Zn, presents a viable alternative. Here, we systematically compare both Zn and Cd anodes in aqueous media, showing that Cd features dendrite‐free deposition, suppressed side reactions, and stable cycling at anode utilization up to 75%. Benefiting from these advances, we demonstrate the first aqueous anode‐free cadmium–bromine (Cd–Br) battery. To boost Cd 2+ plating kinetics in an anode‐free Cd–Br battery, LiCl is introduced into CdSO 4 electrolyte to reconstruct the Cd 2+ solvation shell, resulting in accelerated desolvation and deposition kinetics. Consequently, anode‐free Cd–Br coin cells achieve 87.6% capacity retention after 2000 cycles at 4 C, significantly superior to the anode‐free Zn–Br coin cells with 12.4% retention after only 50 cycles and outperforming other reported aqueous anode‐free systems. Moreover, scaled‐up aqueous anode‐free Cd–Br pouch cells exhibit stable cycling over 1250 cycles with capacity retention of 83.8% and high energy density of 157 Wh kg −1 , far exceeding that of state‐of‐the‐art Zn–Mn and Zn–V pouch cells. This work establishes anode‐free Cd–Br chemistry as a new paradigm in developing high‐energy and highly reversible aqueous batteries.