Browse Articles
Discover research articles across all indexed journals
Non-isomerizing switching strategy for azobenzene photoswitch
Azobenzene photoswitches serve as key building blocks for smart materials due to the controllable isomerization and machinability. However, traditional cis-trans isomeric azobenzene photoswitches are hindered by the thermal instability of the cis structure. In this perspective, we break the limitation by introducing an effective trans-azobenzene photoswitch strategy enabled through excited-state intramolecular proton transfer (ESIPT) in coordination with anti-Kasha fluorescence emission. The photoswitch exhibits a prominent reduction in quantum yield from 0.37 to 0.07 upon switching from the on state to the off state. Femtosecond transient absorption spectroscopy combined with quantitative computational methods elucidated ESIPT and anti-Kasha emission processes. The biological relevance of the design is demonstrated through in-cellular fluorescence modulation of 12 hours and 40 cycles in HeLa cells. By decoupling the photo function from structural rearrangement, we establish a design tactic for photoswitches.
Net Promoter Score inversion may signal problematic digital use
Low-temperature high-quality epitaxial AlN films deposited by plasma-enhanced atomic layer deposition
This work demonstrates low-temperature epitaxial growth of aluminum nitride (AlN) films by plasma-enhanced atomic layer deposition (PEALD). AlN, an ultra-wide bandgap semiconductor with broad applications in optoelectronics and high-power electronics, was deposited on gallium nitride (GaN) templates (GaN-on-sapphire). Single-crystal quality films were obtained at a remarkably low temperature of 300 °C while avoiding additional in situ energetic plasma exposures or ex situ annealing steps, which can damage the film. High crystalline quality is indicated by narrow x-ray diffraction rocking curves of 288 arc sec (0.08°) and 497 arc sec (0.138°) for 10 and 70 nm films, respectively. Continuous high-quality epitaxial growth was maintained across the full film thickness, even at 70 nm, as confirmed by high-resolution transmission electron microscopy and selected area electron diffraction. Atomic force microscopy revealed smooth surface morphologies with an average roughness below 1 nm. The demonstrated epitaxial quality over the 10–70 nm thickness range, achieved at only 300 °C by a PEALD process, enables opportunities for III-nitride integration into thermally sensitive processes (e.g., silicon technology) and into GaN-based devices.
Ten year outcomes in three vessel disease treated by CABG versus PCI in an Eastern European registry
Conformational Quenching in an Engineered Lipocalin Protein Achieves High Affinity Binding to the Toxin Colchicine
Abstract The engineered lipocalin Colchicalin binds the clinically relevant plant toxin colchicine with picomolar affinity. X‐ray structures revealed major loop rearrangements at the open end of the β‐barrel upon ligand binding, suggesting a critical role for protein dynamics. Here, we integrated solution NMR relaxation experiments with molecular dynamics (MD) simulations and Markov modelling to examine conformational dynamics in the free and ligand‐bound Colchicalin on the picosecond‐to‐millisecond timescale. Fast backbone dynamics were comparable in the presence and absence of colchicine, indicating preserved secondary structure. However, large‐scale fluctuations in the structurally variable loops on the microsecond‐to‐millisecond timescale were observed in the apo form. We identified conformational exchange between three states, binding competent, partially closed and fully closed, characterised by loop L3 rearrangements. Colchicine binding quenches these motions, indicating a strong interplay between protein dynamics and ligand recognition. Our results support conformational selection over induced fit as the binding mechanism, highlighting the critical role of slow‐timescale dynamics to enable specific, high‐affinity ligand recognition and providing an important example for rational drug design.
Widely tunable cavity-enhanced backward difference-frequency generation
Difference-frequency generation (DFG) is a powerful technique for generating widely tunable infrared radiation. However, conventional phase-matching schemes may require tuning multiple parameters—such as the wavelengths, crystal temperature, crystal angle, and poling period—to achieve wide tunability, which increases the complexity of practical operation. In this work, we employ a backward quasi-phase-matching scheme with distinctive tuning characteristics and demonstrate pump-enhanced continuous-wave DFG output tunable from 1751 to 2451 nm (700 nm range) in a bulk crystal. The tuning is achieved solely by varying the pump wavelength and the signal wavelength (less than 5 nm), enabling continuous, rapid, and room-temperature operation. The tuning characteristics, power-scaling behavior, and output stability are experimentally verified with the idler wavelength set at 2000 nm. The approach offers a paradigm for widely tunable infrared radiation generation and holds promise for applications in spectroscopy and biomedical sensing.
Extracellular enzymatic activities of octocorals and scleractinian corals under environmental stress
In Situ NMR and Kinetics Reveal Origins of Regioselectivity Differences for Epichlorohydrin Ring‐Opening in Lewis and Brønsted Acid Zeolites
Abstract Altering the quantities and organization of reactive species at active sites enables control of turnover rates and regioselectivities (rate ratios) for ring‐opening of epichlorohydrin (C 3 H 5 ClO) across two orders of magnitude. Kinetic analysis suggests that parallel monomolecular (S N 1) and bimolecular (S N 2) substitution mechanisms contribute to observed rates of C 3 H 5 ClO reactions with methanol (CH 3 OH) over both Lewis (Sn‐BEA) and Brønsted acid (Al‐BEA) zeolites in liquid solvents. In situ solid‐state 13 C‐nuclear magnetic resonance spectroscopy (SS‐NMR) measurements give direct evidence for the proposed ring‐opened carbocations and activated CH 3 OH intermediates over these catalysts. Interpretation of time‐resolved operando 13 C‐SS‐NMR spectra shows that C 3 H 5 ClO‐derived carbocations and CH 3 OH‐derived surface species convert to ring‐opening products through S N 1 and S N 2 reaction mechanisms and subsequently form distinct product regioisomers. These NMR spectra also reveal a concomitant shift from S N 1 to S N 2 reactions with increases in the coverage of CH 3 OH‐derived reactive intermediates achieved by control of the local concentrations of CH 3 OH, C 3 H 5 ClO, and diluting CH 3 CN. This knowledge provides new insight into the role of coverage on regioselectivity and rates of catalytic reactions of organic species at solid–liquid interfaces.
A perspective and review of polarization inverted multilayer BAW resonators based on ScAlN piezoelectric films
The ScAlN film has a large electromechanical coupling and low mechanical loss, enabling RF filters with wide bandwidth, low insertion loss, and a steep filter skirt. In order to meet the growing demand for RF filters operating above 5 GHz, the use of polarization inverted multilayers is continuously being proposed. This Perspective discusses the advantages of overtone mode operation in polarization inverted multilayers for high-frequency bulk acoustic wave (BAW) filter applications: high parallel resonance Qp, high series resonance Qs, high electromechanical coupling, high power capability, and better acoustic isolation from the electrode and supporting medium. Three potential approaches for ScAlN polarization inverted multilayers: film transfer technique, unusual N-polar growth, and external DC voltage application are overviewed. This Perspective includes an experimental demonstration of an acoustic isolation of polarization inverted 30-layer resonators as well as frequency switching between the fundamental mode and the third overtone mode in the currently commercial frequency range of 1.3–3.5 GHz. This article provides a metrics of Q and electromechanical coupling coefficient of recently reported BAW and Lamb wave resonators above 5 GHz, along with experimental data on the elastic tensor, dielectric constant, electromechanical coupling coefficient, temperature coefficient of frequency, and relative Q values in ScxAl1−xN films with varying Sc concentration.
Long-term risk of dry eye disease following gastrectomy and colectomy in a nationwide cohort study
Extrapolative prediction of polymer properties using physics-informed hierarchical descriptors
Accurately predicting the properties of polymers is essential for data-driven materials design. However, such predictions are often challenged by the limited availability of polymer-related data and the fact that high-performance polymers of interest typically lie outside the distribution of existing datasets. In this study, we develop a machine learning model that enhances extrapolative prediction accuracy beyond the training data by leveraging hierarchical, physics-informed descriptors. Specifically, we utilize quantum mechanical (QM) descriptors derived from density functional theory calculations, molecular dynamics (MD) descriptors representing structural and dynamical properties, and force field (FF) descriptors characterizing the interaction parameters used in MD simulations. We investigated two types of extrapolation tasks: extrapolation beyond the range of physical properties and extrapolation to structurally dissimilar molecules. By systematically evaluating all non-zero combinations of QM, MD, and FF descriptors, we find that selected subsets often outperform models using the full descriptor set. This highlights the critical role of dimensionality reduction and descriptor relevance, especially under data-scarce conditions. Comparisons with structure-based models employing molecular fingerprints or molecular graphs further demonstrated the superiority of the proposed model based on selected physics-based descriptors.
Thrombospondin-4 regulates apoptosis of vascular smooth muscle cells after artery transplanted into vein
Achieving fully compensated ferrimagnetism through two-dimensional CrI3/CrGeTe3 heterojunctions
In addition to altermagnets, fully compensated ferrimagnets are another category of collinear magnetic materials that possess zero-net total magnetic moment and exhibit spin-splitting, making them promising for low-energy spintronics, high-density data storage, and high-sensitivity sensors. Although many methods, such as alloying, external electric field, Janus engineering, ferroelectric field, and spin ordering, have been proposed to achieve fully compensated ferrimagnetism, these approaches either face experimental difficulties or produce a small spin-splitting or are volatile. Here, we propose to form vertical heterostructures by stacking two different but equally magnetized two-dimensional ferromagnetic materials. If an A-type antiferromagnetic ordering is satisfied, a fully compensated ferrimagnet can be formed. This vertical heterostructure approach is insensitive to lattice matching and stacking manner, thus being more conducive to experimental realization. Through first-principles calculations, we verify our proposal with several examples, focusing in particular on CrI3/CrGeTe3 heterojunction composed of experimentally synthesized CrI3 and CrGeTe3 monolayers. The calculations show that CrI3/CrGeTe3 is a fully compensated ferrimagnet, with pronounced spin-splitting, and that tensile strain is more favorable for achieving fully compensated ferrimagnetism. Our work provides an experimentally feasible strategy for realizing fully compensated ferrimagnetism, thereby further advancing the development of this field.
The impact of radical hepatectomy on prognosis of patients with hepatic alveolar echinococcosis complicated with microvascular invasion
Gradient-segmented flag triboelectric nanogenerator for omnidirectional wind sensing and self-powered warning
Extreme wind events are increasing due to environmental degradation, often causing power outages and safety risks. To enable reliable sensing under such conditions, a gradient-segmented flag triboelectric nanogenerator is developed for omnidirectional wind sensing and self-powered warning. The polyethylene terephthalate-based flag with gradient thickness provides tunable stiffness and mass distribution, optimizing response range and sensitivity. A cantilever beam model elucidates the segment-dependent dynamics. The single-segment device achieves ∼500 nC charge output and 215 mW/m2 power density at 6.5 m/s, powering 434 LEDs, while the three-segment design enables accurate wind speed detection from 2 to 7 m/s. A hybrid system integrating both modes and a wind direction–adaptive structure ensures omnidirectional performance. This work demonstrates a robust, self-sustained solution for wind sensing and warning, capable of operating during power failures and supporting disaster risk mitigation.
Research on the transmission mechanisms of global intangible cultural heritage: a case study of Chinese Oolong tea production techniques
Hybrid improper ferroelectricity and phase transition in La2Sr(Sc1− <i>x</i> In <i>x</i> )2O7 ceramics
Oxygen octahedral rotation is essential for hybrid improper ferroelectrics (HIFs), but interlayer rumpling will compete with oxygen octahedron rotation, leading to the suppression of ferroelectricity in layered perovskite materials containing trivalent cations at the B-site. In the present work, single-phase dense La2Sr(Sc1−xInx)2O7 ceramics with double-layered Ruddlesden–Popper structures have been prepared, and the presence of room-temperature HIF is evidenced by the ferroelectric hysteresis loops. The polar A21am phase is adopted at room temperature, and it will transform into a nonpolar Amam phase above the Curie temperature. The Curie temperature increases linearly with the content of In3+ cation and with decreasing tolerance factor, whereas the ferroelectric polarization decreases with the substitution of In3+ cation at the B-site owing to the suppression of oxygen octahedral rotation. The present work demonstrates the room-temperature HIF in La2Sr(Sc1–xInx)2O7 ceramics and emphasizes the essential role of tolerance factor in determining the Curie temperature.
Negative expansion resistance (NER) phenomenon predicts hemodynamically non-significant coronary lesions
Electric field tuning phase transition behavior and the discharge performance of (Na0.5Bi0.5)TiO3 ferroelectric ceramics under shock compression
Ferroelectric materials, owing to their polar structures and spontaneous polarization, can rapidly release charges under shock loading, offering striking potential for high-power pulsed power sources and energy conversion devices. In practical applications, ferroelectrics often operate under coupled pressure–electric field environments, where their phase transition behavior plays a key role in determining electrical responses. However, the phase transition mechanisms and phase diagrams under such coupled conditions remain unclear, and the output current lacks effective regulation. Here, the discharge behavior of (Na0.5Bi0.5)TiO3 ferroelectric ceramics under coupled pressure–electric field conditions is investigated. Experiments reveal that increasing shock pressure promotes the ferroelectric–paraelectric transition and enhances charge release, while the electric field suppresses the transition, enabling effective control of the peak output current and phase transition ratio. This breaks the limitation of fixed current amplitude under shock conditions. Furthermore, a three-dimensional electric field-pressure-charge release map and a pressure–electric field phase diagram are established, unveiling the competitive interplay between pressure and electric field in governing the ferroelectric–paraelectric transition. These findings provide guidance for the design and application of lead-free ferroelectric ceramics in extreme multi-field environments.