Browse Articles

Temporal transcriptomic dynamics in rat spinal cord after tibial fracture unveil crosstalk between spinal cord and bone

Memristive synapse based on perovskite Cs3Cu2I5 for reservoir computing

Perovskite memristors have attracted considerable attention for their potential in emulating artificial synapses. However, the widespread use of the toxic lead-based perovskites poses significant challenges to futural application. In this work, we developed a lead-free memristor with an Ag/PMMA/Cs3Cu2I5/ITO architecture, in which the Cs3Cu2I5 halide perovskites functional layer was fabricated by physical vapor deposition. The memristor demonstrated a data retention time of 104 s and stable resistive switching behavior over 100 cycles under electrical pulses stimulation. Furthermore, it emulated a range of biologically relevant synaptic functions, including paired-pulse facilitation, short-term plasticity, long-term plasticity, spike-amplitude-dependent plasticity, spike-number-dependent plasticity, and spike-duration-dependent plasticity. Capitalizing on its nonlinear dynamics and short-term memory characteristics, the device was further integrated into a reservoir computing (RC) system. The RC system demonstrated strong recognition performance and robustness when tested with distorted digital image datasets. These results suggest that the Cs3Cu2I5-based memristor provides a promising, environmentally friendly platform for next-generation artificial intelligence hardware.

Mechanisms of mitochondrial reactive oxygen species action in bone mesenchymal cells

Antisolvent‐Bathing Strategy with Ultra‐Wide Processing Window for Making High‐efficiency Perovskite Solar Cells in Ambient Air

Abstract Most record‐efficiency perovskite solar cells rely on spin‐coating with antisolvent dripping, which is fundamentally incompatible with roll‐to‐roll (R2R) manufacturing. The crystallization kinetics of dynamic wet film during spin coating differs widely from the static wet film during R2R fabrication, which makes the existing crystallization control strategies become inapplicable while upscaling. The crystallization regulation of static wet film remains a critical challenge, particularly under ambient conditions. In this study, we employed the antisolvent‐bathing method that can efficiently regulate the crystallization process of static wet films made by drop coating. Through systematic investigation of solvent‐antisolvent interdiffusion kinetics and in‐situ crystallization monitoring via time‐resolved UV–Vis spectroscopy, we identify alkyl chlorides (particularly chloroform) as optimal bathing agents. The champion device made by CF bathing achieved an efficiency of 24.49% under ambient conditions (RH 30%–50%), representing the highest efficiency for perovskite solar cells made by the antisolvent bathing method. The device showed negligible decay after 2256 h storage in N 2 atmosphere. The method demonstrates exceptional environmental resilience to humidity and solvent accumulation, accompanied by an ultra‐wide processing window (10 s–10 min bathing duration, >2 min post‐bathing delay tolerance).

Marrying Perona Malik diffusion with Mamba for efficient pediatric echocardiographic left ventricular segmentation

Abstract Segmenting echocardiographic images is a crucial step in assessing heart function, as clinical indicators can be obtained by precisely delineating the left ventricle. The success of subsequent heart analyses depends entirely on the precision of this segmentation. However, echocardiography is characterized by ambiguity and heavy background noise interference, making accurate segmentation more challenging. Present methods lack efficiency and are prone to mistakenly segmenting some background noise areas, such as the left ventricular area, due to noise disturbance. To address these issues, we introduce P-Mamba, which integrates the Mixture of Experts (MoE) concept for efficient pediatric echocardiographic left ventricular segmentation. Specifically, we utilize the recently proposed ViM layers from the vision mamba to enhance our model’s computational and memory efficiency while modeling global dependencies. In the DWT-based (Discrete Wavelet Transform) Perona-Malik Diffusion (PMD) Block, we introduce a block that suppresses noise while preserving the left ventricle’s local shape cues. Consequently, our proposed P-Mamba innovatively combines the PMD’s noise suppression and local feature extraction capabilities with Mamba’s efficient design for global dependency modeling. We conducted segmentation experiments on two pediatric ultrasound datasets and a general ultrasound dataset, namely Echonet-dynamic, and achieved state-of-the-art (SOTA) results. Specifically, on the Pediatric PSAX (8959 images) and Pediatric A4C datasets (6425 images), we achieved Dice scores of 0.922 and 0.906, respectively; on the EchoNet-Dynamic dataset (19882 images), we achieved a Dice score of 0.931. Leveraging the strengths of the P-Mamba block, our model demonstrates superior accuracy and efficiency compared to established models, including vision transformers with quadratic and linear computational complexity.

Optical-enhanced, self-powered UV photodetectors based on VO2/SiC heterojunction

The development of ultraviolet (UV) heterojunction photodetectors plays a critical role in a wide range of applications, including environmental monitoring, biomedical imaging, and secure communications. In this study, we present self-powered solar-blind UV photodetectors based on a vanadium dioxide (VO2)/silicon carbide (SiC) heterojunction. The integration of the narrow-bandgap VO2 film with the wide-bandgap SiC creates a Z-type heterojunction, which significantly enhances photocurrent due to the built-in electric field at the interface. Furthermore, a notable increase in photocurrent is achieved by the deposition of gold nanoparticles on the device's surface. This modification enhances the local electric field via the plasmonic effects, thereby further improving photocurrent. The synergistic effect of the plasmonic field enhancement effect and the built-in electric field of the heterojunction enhances the generation, separation, and transport efficiency of photogenerated carriers, ultimately resulting in a superior photocurrent response. The self-powered UV heterojunction photodetector offers a promising strategy for the advancement of SiC-based optoelectronic devices.

SMAD1/5-mediated recruitment of the histone demethylase KDM1A controls cell fate programs in embryonic stem cells

Fe─N ₄ ‐Anchored Carbon Layer Patched TiO ₂ Cavities to Construct an “In‐Lattice Heterojunction” for Enhanced Photocatalytic Nitrogen Reduction Reactions

Abstract Efficient charge separation and carrier transfer are critical determinants of the performance of photocatalysts for nitrogen reduction reactions (NRR) which are critical for agricultural and chemical industries. In this study, a novel type of heterostructure, termed an “In‐Lattice heterojunction”, has been constructed by introducing a Fe─N 4 ‐anchored carbon layer (Fe─N─C) onto the surface of defective TiO 2 (D‐TiO 2 ), as well as implanting it into the cavities of D‐TiO 2 . The in‐lattice heterojunction, defined as FNCTO, achieves efficient radial carrier transfer along the Ti─C─N─Fe in‐lattice atomic channel and greatly promoted N 2 adsorption benefiting photocatalytic NRR. Thus, FNCTO exhibits an excellent photocatalytic N 2 reduct`ion into NH 3 activity (88 µmol g −1  h −1 ), obviously higher than that of Fe─N─C sites on noncavity P25, illustrating the crucial role of cavity patch induced in‐lattice heterojunction. This study paves a way for the development of high‐performance Fe─N─C atomic photocatalysts based on noncarbon materials.

Diagnosis of misalignment faults using the DTCWT-RCMFDE and LSSVM algorithms

Thermal stress stabilized thick perovskite heterostructures for radiation detection

Integrating lead halide perovskite onto the standard readout circuit substrate is the path to the commercialization of perovskite-based radiation detection and imaging. However, due to the large thermal expansion coefficient difference between perovskite and inorganic substrate, such heterostructure faces the challenge of thermal stress induced mechanical instability. This problem will be extremely severe for the thick perovskite film for radiation detection because the thermal strain energy accumulates with film thickness. Here, first by theoretical analysis, we quantized the thermal stress instability and found that a temperature variation of only 20 °C around room temperature will suffice to delaminate a 100 µm thick perovskite film from the substrate, which prediction agrees with experiments. We then proposed to promote the heterostructure's mechanical stability by increasing the perovskite nucleation rate on inorganic substrate to enhance the interface adhesive energy. Based on a sacrificial seeding layer, we realized stable interface between the thick perovskite film and the typical inorganic substrate, including indium tin oxide, silicon, and gallium nitride that can withstand at least 100 cycles of temperature variation between 25 and 150 °C and then fabricated high performance radiation detectors based on such heterostructures.

Reduced complex I activity in the retinal pigment epithelium, but not in rod photoreceptors, affects light signaling without impacting cell survival

Synthesis, photoluminescence properties, solvent effect in molecular structure level, topology, and docking studies on Sulfa drug derivative

On the criteria of jet types during a bubble collapse near the tissue-mimicking boundary

The collapse of a cavitation bubble near a tissue membrane generates intense microscopic flows, emits shock wave, and can lead to membrane damage. Experimental works show that the collapse of a cavitation bubble leads to more violent two axial jets flow with decreasing bubble–boundary distance. The critical stand-off distance for the formation of such a jet flow varies largely under different material properties. We investigate the evolution of cavitation induced jet flow experimentally and theoretically comprehensively. A dimensionless impulse is proposed based on image-source model, considering the influence of boundary. A regime map is constructed, revealing a unique law for various materials. The current work may offer insight into the application of cavitation bubbles in biomedical engineering.

ATP hydrolysis-driven structural transitions within the Saccharomyces cerevisiae Rad51 and Dmc1 nucleoprotein filaments

Effect of gastrointestinal digestion on the stability and cytotoxicity of conventional and pegylated liposomes encapsulated with stigmasterol and its esters

Abstract Conventional and PEGylated liposomes encapsulated with stigmasterol and its esters were prepared, and their stability and cytotoxicity during in vitro gastrointestinal digestion were determined. The release of stigmasterol and its oxidation products were analyzed using GC-FID. The cytotoxicity before and after digestion was assessed using human normal small intestinal HIEC-6 cells and colon mucosa CCD 841CoN cells. Both liposome PEGylation and the chemical structure of the encapsulated compounds affect the stability and cytotoxicity of the liposomes after gastrointestinal digestion. Esterification of stigmasterol had an effect on the encapsulation of stigmasterol in liposomes, especially PEGylated liposomes, but the level of fatty acid saturation had no significant influence. PEGylation of liposomes did not inhibit sterol oxidation, but in fact led to the formation of oxidation derivatives. Gastrointestinal digestion increased the cytotoxicity of liposomes with stigmasterol (L-St), but liposomes encapsulated with stigmasterol esters had lower cytotoxicity than did undigested liposomes. PEGylation of liposomes did not cause an increase in cytotoxicity to the small intestinal or colon mucosa cells. However, it should be highlighted that the cytotoxic effects of the digested PEGylated liposomes were considerable higher in colon CCD 841CoN cells than in small intestinal HIEC-6 cells.

Negative thermal expansion in spiral magnetic Lu2Fe16.5Ru0.5

Negative thermal expansion (NTE) has been a topic of interest for magnetic metals due to its potential for applications. Knowledge of the relationship between magnetism and the NTE can be conducive facilitate the exploration of both new magnetic functions and NTE systems. In this work, we apply neutron diffraction on a spiral magnetic Lu2Fe16.5Ru0.5 (space group: P63/mmc) to study the evolution of magnetic structure and thermal expansion under various magnetic fields. Strong negative thermal expansion emerges along the c axis over magnetic ordering temperature range from 10 to 200 K, yet normal positive thermal expansion is observed within basal plane, thus yielding a volumetric low thermal expansion (αv = +2.9 × 10−6 K−1, 10–200 K). Moreover, a high magnetic field of 2 Tesla is found to suppress the interplanar spiral magnetic ordering but have weak impact on NTE. These findings imply magnetic disorder may be more essential than the change of magnetic texture for inducing a thermal expansion anomaly in such NTE systems.

Molecular recognition of fungal methylated glucosylceramides by ETD151 defensin

Bottom‐Up Regulation of Perovskite Growth and Energetics via Oligoether Functionalized Self‐Assembling Molecules for High‐Performance Solar Cells

Abstract Self‐assembling molecules (SAMs) are widely used as interfacial layers to optimize the surface properties of nickel oxides (NiO x ) in inverted perovskite solar cells (PSCs). However, less attention is paid to the effect of SAMs on the regulation of perovskite growth and energetics. Here, based on the donor‐acceptor molecular backbone, an oligoether chain is introduced with different chain lengths to endow two novel SAMs, namely, EPA and MEPA, with good capability of bottom‐up regulation of perovskite formation and energetics. Compared to the model SAM MPA, EPA and MEPA can render NiO x with better coverage and conductivity. Moreover, the oligoether chain‐containing SAMs are able to assist the formation of perovskite film with ordered growth, high crystallization, and importantly well‐matched energy level alignment at the top surface, especially for MEPA. Consequently, a remarkably high efficiency of 25.50% is realized for NiO x /MEPA‐based PSCs along with good device stability, which can maintain 90% of the initial efficiency under ISOS‐L‐1 conditions over 1260 h.

Urban governance to support adaptable solutions for conversion of residual street spaces into social spaces

Abstract Abandoned residual street spaces, frequently marginalised in formal urban planning frameworks, represent a significant yet unrealised resource for enhancing urban liveability, especially within the complexities of dense historic urban neighbourhoods. This study investigates how such underutilised spaces can be strategically transformed into vibrant social hubs. Focusing on the Castello neighbourhood in the historic centre of Cagliari, Italy, the research adopts a unique mixed-methods approach grounded in a sequential exploratory design. It begins with spatial analysis using space syntax techniques, including segment analysis, axial analysis, and visibility graph analysis, followed by GIS-based land use mapping and field-based qualitative assessments to identify and prioritise residual spaces based on their social potential. The findings highlight several high-potential sites characterised by pronounced spatial configuration and contextual qualities, suggesting practical insights into the design and governance of adaptive social spaces. The original contribution of this study lies in its incorporated and replicable methodological framework that combines quantitative spatial analysis with qualitative urban evaluation. The results not only advance the theoretical discourse on residual urban space but also provide pragmatic strategies for inclusive urban regeneration. The proposed framework is applicable across diverse urban contexts, offering a scalable model for cities aiming to enhance sociability through the adaptive reuse of neglected urban fragments.

Demonstration of <b> <i>β</i> </b>-Ga2O3 vertical Schottky barrier diode with mesa termination assisted partially suspended field plate on MOCVD-grown epitaxial wafer

This Letter demonstrates a beta-phase gallium oxide (β-Ga2O3) vertical Schottky barrier diode (SBD) with mesa termination assisted by a partially suspended field plate, which is fabricated on the epitaxial thick film grown by metal–organic chemical vapor deposition. The epitaxial film features a high-quality, smooth surface and high mobility, laying the foundation for achieving high performances. In the device aspect, the mesa termination and the partially suspended field plate, which can be formed simultaneously by adding Cl2 during the inductively coupled plasma etching process to facilitate isotropic etching of β-Ga2O3, effectively mitigate the electric field crowding phenomenon at the device edge, thereby reducing the electric field peaks both in the epitaxial layer and dielectric layer and improving the breakdown voltage (BV). The experimental results show that the proposed SBD achieves a high BV of 3.45 kV and a low specific on resistance of 3.88 mΩ cm2, yielding a high power figure of merit of 3.07 GW/cm2. Meanwhile, a low forward voltage (at 100 A/cm2) of 1.25 V can also be obtained, verifying the low conduction loss property.