Browse Articles

Ultrafast laser-induced anharmonic lattice dynamics and nonlinear optical modulation in croconic acid

Ultrafast laser excitation offers a powerful means to modulate material properties on femtosecond timescales. Here, we investigate croconic acid, a hydrogen-bonded organic ferroelectric, using real-time time-dependent density functional theory to uncover the microscopic mechanisms of light-induced structural transitions and nonlinear optical responses. High-order harmonic generation in croconic acid is found to be highly sensitive to proton displacement within hydrogen bonds, with polarization switching reshaping internal electronic asymmetry and modulating intersite electron currents. Subangstrom-scale lattice distortions induce marked enhancements or suppressions in the harmonics, highlighting the extreme sensitivity of the nonlinear response to hydrogen-bond configuration. These results reveal a light-driven electron–proton–lattice interaction mechanism in organic ferroelectrics, providing a route toward tunable ultrafast photonic and optoelectronic devices based on molecular materials.

Author Correction: Macrophage lineage cells-derived migrasomes activate complement-dependent blood-brain barrier damage in cerebral amyloid angiopathy mouse model

Tunable magnetism and anomalous Hall effect in magnetic Weyl semimetal Co3Sn2S2

As a magnetic Weyl semimetal with broken time-reversal symmetry, kagome-lattice Co3Sn2S2 exhibits various exotic transport phenomena due to its nontrivial band structure. Here, we selected Fe and Ni as representative dopants and employed both individual and co-doping strategies to regulate the magnetic and transport properties. At specific doping concentrations, both elements induce significant changes in coercivity and magnetic moment, which are clearly reflected in the switching field and magnitude of the anomalous Hall effect (AHE). Qualitative and quantitative analysis based on the separation models and theoretical calculations reveal that the AHE is dominated by the intrinsic mechanism related to the Berry curvature of electronic band structures. This work demonstrates that appropriate disordered doping can effectively introduce domain wall pinning behavior while retaining the intrinsic Berry curvature dominant essence of the AHE, providing important guidance for the design of AHE in magnetic topological materials.

Design of high-performance sustainable aluminum alloy series for laser additive manufacturing

Optimal detuning in optically pumped 10 <b> <i>λ</i> </b> ultraviolet vertical-cavity surface-emitting lasers for temperature stability and low threshold

In vertical-cavity surface-emitting lasers (VCSELs), the lasing wavelength is defined by the longitudinal cavity mode. The spectral misalignment between the resonance wavelength and the gain peak, known as detuning, is crucial for the device performance. Temperature also influences detuning since the gain peak red shifts faster than the resonance wavelength when the temperature increases. These important effects have not been explored in detail for ultraviolet (UV) VCSELs despite the significant heating that is expected due to high electrical resistance and high thermal impedance. Here, we studied the threshold and detuning dependence in optically pumped AlGaN-based UVB and UVC VCSELs with different cavity lengths operated at different temperatures. The cavity lengths of the VCSELs, fabricated from the same epitaxial material, are varied by post-growth deposition of HfO2 spacer layers with different thicknesses. The results show a strong relation between the threshold and the detuning, where VCSELs have thresholds around 5 MW/cm2 for a nominal (operational) detuning of −2.5 nm (∼−1 nm), and below 1 MW/cm2 when the nominal (operational) detuning is set between 2 and 3 nm (1–3 nm) with a minimum threshold of 0.23 MW/cm2. Additionally, the temperature dependence of the VCSELs' thresholds is investigated and compared by temperature-dependent photoluminescence and an empirical relation. The VCSELs with lower thresholds at room temperature are, on average, 20 times less sensitive to temperature than those with higher thresholds at room temperature, suggesting that VCSELs with a nominal detuning of 2–3 nm are the optimum design choice.

Partial restoration of mitochondrial dysfunction by AAV-Ant1 protects from dilated cardiomyopathy in Ant1-/- plus mtDNA mutant mice

Erratum: “Even-in-magnetic field part of transverse resistivity as a probe of magnetic transitions” [Appl. Phys. Lett. <b>126</b> , 172404 (2025)]

An unconventional pathway to correlate the octahedral tilt coupling and spin-orbit reconstruction at oxide interfaces

THz intraband absorption in HgTe nanocrystals in the linear and nonlinear regimes

With their tunable intraband absorption in the THz range and carrier dynamics on the order of tens of picoseconds, large HgTe nanocrystals (NCs) hold strong potential for THz optoelectronic devices, including modulators and detectors. Their THz intraband absorption has been attributed to multiple transitions of single carriers between quantized states. However, since most investigations have been limited to room temperature, many fundamental physical questions remain open. Here, we investigate the THz intraband absorption in both linear and nonlinear regimes across a broad temperature range. Our results highlight the essential role of thermally activated carriers in the linear regime, which has been so far neglected in existing models, and show that nonlinear intraband absorption in large HgTe NCs arises from an increase in chemical potential combined with changes in electronic temperature, both influenced by saturation effects associated with the progressive filling of electronic states. Furthermore, using mid-infrared pump–THz probe experiments, we probe the carrier dynamics and demonstrate that surface traps and ligand modes have a negligible effect on hot carrier recombination. The dominant recombination pathway is attributed to non-radiative interband processes mediated by optical phonon emission. This work provides new insight into the physical mechanisms underlying the THz intraband absorption of HgTe NCs in both linear and nonlinear regimes, refines their theoretical description, and highlights the potential of large HgTe NCs for THz optoelectronic devices such as modulators and detectors.

Exercise-induced histone lactylation in monocyte-derived macrophages restores cardiac immune homeostasis and function in sepsis-induced cardiomyopathy

Abstract An active lifestyle protects against cardiovascular diseases, yet its mechanisms in modulating the cardiac immune environment and preserving cardiac function remain unclear. Here, we identify a subpopulation of monocyte-derived cardiac macrophages, termed iNOS + Arg1 + macrophages, which simultaneously express pro-inflammatory and pro-reparative genes in exercised male mice. Inhibiting either pro-inflammatory iNOS or pro-reparative Arg1 in these macrophages counters the exercise-induced cardiac function preservation. Mechanistically, exercise enhances glycolysis in monocytes, increasing lactate production and driving histone lactylation at H3K18, mediated by p300 as the relevant lactyltransferase and counterbalanced by HDAC2 as deacetylase. H3K18la accelerates the transition of cardiac macrophages to a pro-reparative state, restoring immune homeostasis and preserving cardiac function. Notably, human monocytes from physically active individuals exhibit elevated levels of Pan-Kla and H3K18la compared to those from sedentary individuals. Importantly, adoptive transfer of highly histone-lactylated monocytes restores cardiac function in sepsis-induced cardiomyopathy, which might translate into a promising therapeutic strategy for cardiomyopathy.

A sensor for helium leakage detection and orientation based on a two-dimensional acoustic topological material

Helium, a scarce gas, is widely used in various fields, like aerospace, semiconductor manufacturing, biomedicine, etc. However, the detection of helium leakage remains challenging because helium is an inert gas with exceptional chemical stability, and, thus, traditional gas sensors working with gas absorption cannot be applied in helium sensing. In this work, we create a helium sensor on the basis of an acoustic topological material, which works with the shift of topological corner states and does not rely on chemical absorption. The sensor is created with a two-dimensional Kagome structure, producing corner states at three corners. Theoretical analysis and experimental measurement demonstrate that the sensor possesses a constant relative sensitivity, which is marginally influenced by working conditions. As a result, the sensor can be applied in extremely wide ranges of temperature and humidity and does not require calibration. Furthermore, three corner states arising at distinct positions are adopted to orientate the leakage point. Additionally, because of topological protection, the corner states are marginally influenced by defects in the sensor, and, thus, multiple and large gas input holes are allowed to considerably speed up the response and recovery of the sensor. The sensor exhibits good stability, repeatability, and rapid response without basement shift in helium detection and is available in the detection of various inert gases. Meanwhile, this work provides insights into the application of two-dimensional acoustic topological materials.

Structural basis for genome-wide site-specific DNA recognition by Nuclear Factor IA

Transition metal oxide-based heterostructure memristors for nonvolatile ternary resistive switching realization

Memristors are promising candidates for next-generation data storage due to their exceptional resistive switching (RS) capabilities, characterized by ultra-fast response times, low power consumption, and outstanding stability. However, current memristor technology achieves a storage capacity of only one bit per cell, which severely restricts the storage density of individual devices. Herein, we demonstrate Y2O3/TiO2 heterostructure-based memristors capable of binary and ternary data storage, with tunable functionality achieved by modulating electrical stress conditions. Under low-electrical stress conditions (−1.50 V/1.50 V), the Y2O3/TiO2 heterostructure memristor exhibits reliable binary RS behavior, featuring low cycle-to-cycle variability, narrow switching voltage distributions, and robust retention (&amp;gt;104 s). In contrast, ternary RS operation is activated under high-electrical stress conditions (+2.0 V/−2.5 V), achieving an enhanced resistance ratio (&amp;gt;102) with distinct intermediate and high-resistance states. Furthermore, the mechanisms and physical models for switching performance under different electrical stresses are thoroughly elucidated. This work introduces a heterostructure strategy to enhance memristor storage capacity, offering a competitive pathway for developing high-density logic hardware systems with advanced memory capabilities.

A synthetic cell phage cycle

Ultralow Thermal Conductivity in Layered CuGe ₂ Se ₃

Abstract Unraveling the relationship between thermodynamic factors, interatomic interactions, and electronic structure remains a crucial yet elusive challenge in the discovery of novel materials in solid‐state (SS) chemistry. In the quest for new thermoelectric (TE) materials, we overcame that fundamental problem for the case of CuGe 2 Se 3 , whose synthesis, unique crystal structure, and transport properties are reported herein. The giant two‐dimensional (2D) structure of CuGe 2 Se 3 , consisting of Se/(Cu─Ge)/Se and Se/(Ge─Ge)/Se slabs stacked along the c ‐axis, exhibits short Cu─Ge and Ge─Ge interactions, as evidenced by single‐crystal X‐ray diffraction (SCXRD) and SS NMR spectroscopic studies. These homopolar bonds might be surprising, as such interactions are rarely observed in group IV‐chalcogenides. The compound is thermally stable up to ∼823 K. Transport properties measurements revealed a high Seebeck coefficient (∼373.6 µV·K −1 ) and ultralow thermal conductivity (∼0.35 W·m −1 K −1 ) at 755 K, ascribed to its weak bonding interactions. We followed up with a theoretical analysis to gain insight into its structural peculiarities, focusing on vibrational properties and the nature of chemical bonding. The formation of Ge─Ge bonds is favored in light of the presence of multicenter bonds, which receive contributions from stereochemically non‐active Ge lone pairs.

Synergism of CoFe2O4 additives and P(VDF-TrFE) barriers in crystallization, polar phase, and electrocaloric effects of multilayer composite thin films

In the last decade, refrigeration technology based on electrocaloric effect (ECE) has become a research hotspot in the ferroelectric field, profiting from being environmentally friendly and highly efficient. In this paper, we fabricated CoFe2O4/P(VDF-TrFE) multilayer composite films on an fluorine-doped tin oxide glass by integrating CoFe2O4 additives and P(VDF-TrFE) barriers to innovate the structures and ECE performances. As a result, the multilayer composite films showed comprehensive superiorities such as higher crystallization, smaller grain size, more polar phase, smaller coercive fields, and higher polarizations than the reference P(VDF-TrFE) films. The composite films have acceptably low leakage currents far below micrometers at a high electric field of 100 MV m−1. We measured a giant ECE temperature change of 25.9 K and an ECE strength of 0.37 K m MV−1 at a relatively small external field of 70 MV m−1 for ferroelectric polymers, extremely competitive over the reported. The Landau–Devonshire theory ascertained the reliability of the ECE performance by the indirect method and predicted a high ECE temperature change of 54 K under 140 MV m−1 of the multilayer composite films. The giant ECE CoFe2O4/P(VDF-TrFE) multilayer composite films are prospective for solid-state refrigeration.

Persistent pneumococcal colonisation in antiretroviral-treated HIV infection is associated with nasal inflammation

LC dual-parameter coplanar coil decoupling method based on reverse adjacent coil structure design

In LC multi-parameter sensors, coil mutual inductance induces crosstalk, causing resonant shifts and signal interference. This study proposes a reverse adjacent coil structure that generates opposing magnetic fields to suppress mutual inductance and reduce crosstalk. A theoretical coplanar inductance model was established, with a derived mutual inductance formula and applicable conditions. Coplanar inductor behavior was analyzed via HFSS simulations, and two LC circuits were constructed to examine dual-resonant interactions. Experiments validated the model by varying two capacitor values and fabricating capacitive sensors. This passive method preserves signal independence and accuracy while reducing complexity. It is well-suited for thin-film wireless sensing, enabling precise and reliable synchronous measurements.

Chiroptical isomerization in chiral covalent organic frameworks with identical mesoscopic helicity

(S <b>+</b> C)-band optical amplification enabled by hybrid lanthanide-doped nanocomposites

Polymer waveguide devices have garnered significant attention in broadband communications due to their low propagation losses and ease of on-chip integration. Lanthanide-doped nanocrystals, recognized for their excellent optical properties, have been extensively explored as potential gain media for these devices. However, most research has focused on erbium- or thulium-doped systems, with amplifiers typically confined to the C-band or S-band. Expanding the near-infrared emission range of lanthanides to enable wideband optical amplification remains a key challenge. Herein, we present a nanoparticle hybridization strategy that achieves broadened near-infrared emission with a full width at half maximum of 126 nm. The absence of mutual interaction between the distinct emitting centers enables the fabricated optical amplifier to deliver independent yet complementary amplification across the entire S + C telecommunication bands with high gain. Our findings provide a robust platform for developing high-performance, broadband optical amplifiers, opening promising avenues toward advanced multiplexing and signal processing in next-generation communication systems and integrated photonic circuits.