Browse Articles

Engineered Nonheme Iron Enzymes Enable Asymmetric Hydrogenation of Alkenes

Selenium-doped ultrasound micro-arc oxidized calcium-phosphate coatings on Ti-13Nb-13Zr: functional and biological characteristics

Abstract Ultrasound-assisted micro-arc oxidation (UMAO) offers enhanced control over electrochemical oxidation processes by modifying discharge behavior and mass transport during coating growth. In this study, a Ti-13Nb-13Zr alloy was processed by UMAO in calcium/phosphate-based electrolytes, with and without low-dose selenium incorporation, to elucidate process–structure–property relationships in porous oxide coatings. Selenium was introduced as a minor electrolyte component to investigate its influence on coating formation, interfacial characteristics, and functional performance. The resulting coatings were systematically characterized in terms of surface morphology, chemistry, topography, wettability, mechanical and tribological behavior, electrochemical stability, and biological response. Selenium incorporation altered the coating growth process, leading to increased surface wettability and surface free energy, accompanied by changes in topographical parameters indicative of modified surface functionality. All coatings exhibited cytocompatibility, maintaining osteoblast viability above the 70% threshold. Among the investigated variants, the Se350 coating (350 V, Se-doped) demonstrated the most favorable mechanical response, with increased hardness and elevated H/E and H³/E² ratios, which translated into improved wear resistance. Tribological testing in Ringer’s solution revealed a lower and more stable coefficient of friction for Se350 compared with its selenium-free counterpart, indicating enhanced durability under lubricated sliding conditions. In addition, selenium-doped coatings significantly suppressed Escherichia coli biofilm formation. Electrochemical investigations confirmed that UMAO processing improved corrosion resistance relative to the uncoated alloy, although the Se350 coating exhibited reduced long-term stability, likely associated with increased porosity and altered transport pathways within the coating. Overall, the results demonstrate that low-dose selenium incorporation during ultrasound-assisted micro-arc oxidation enables effective tuning of interfacial structure and multifunctional performance, highlighting the potential of this processing strategy for advanced surface engineering of titanium alloys.

Structure-based functionality of a multi-domain periplasmic chitodextrinase from marine bacterium Vibrio cholerae

Concave and Convex Molecular Curvature Modulates Spatial Electronic Environments for Controlled Electrocatalysis

A Neutral “Masked” Diborene and Its Reactivity Toward Metal‐Free Pyridine Homocoupling

ABSTRACT An unprecedented neutral “masked” non‐external‐donor‐stabilized diborene is generated via intramolecular arene dearomatization of an N‐heterocyclic imine (NHI)‐supported free diborene. The free diborene intermediate is photochemically accessible from the masked form, as supported experimentally through chalcogenation reactions. Computational studies elucidate an alkyne‐like bonding pattern and a triplet ground state with a Δ E S‐T = +1.2 kcal mol −1 for the NHI‐supported free diborene. Remarkably, the “masked” diborene activates pyridines, promoting transition‐metal‐free C−C bond formation with high C2 regioselectivity to afford homocoupling products under mild conditions. Mechanistic investigations reveal that stepwise coordination and B−C bond cleavage produce a bis‐pyridine diborene intermediate, which undergoes reductive coupling via intrinsically strong double single‐π‐electron transfer from the B═B unit to the intramolecular pyridine ligands. Furthermore, oxidation with p ‐benzoquinone allows the release of free 2,2′‐bipyridine derivatives. These findings provide access to insight into a hitherto elusive free diborene species, establish a previously unknown reactivity mode for diborenes, and demonstrate that this “masked” diborene functions as an exceptionally powerful double single‐electron donor with the potential to mimic transition‐metal behavior in the construction of organic molecules.

Deep learning classification of nasal anatomical variants on computed tomography for endoscopic sinus surgery

Abstract Endoscopic sinus surgery (ESS) carries risks such as vision loss and intracranial injury due to the proximity of critical structures and unrecognised anatomical variants. We developed convolutional neural networks (CNNs) to detect free-floating anterior ethmoidal arteries (FFAEA), Onodi cells, and Haller cells on coronal sinus CT, and evaluated BioMedCLIP, a biomedical vision-language model (VLM), in a few-shot setting. CT scans from 122 ESS patients were anonymised, standardised coronal CT images were captured, and variant presence was annotated. Five ImageNet-pretrained CNN backbones were assessed using repeated patient-wise five-fold cross-validation across 40 configurations. The best CNNs achieved balanced accuracies of 77.8 ± 2.3% (FFAEA), 74.6 ± 2.5% (Onodi), and 63.7 ± 6.2% (Haller). BioMedCLIP achieved 65.5 ± 3.2%, 63.8 ± 1.8%, and 73.5 ± 3.6%, respectively, outperforming CNNs for Haller cell detection while providing competitive performance for the other variants. These models demonstrate proof-of-concept performance for automated identification of selected sinonasal variants on standardised coronal CT images under internal patient-wise cross-validation.

The multiple sclerosis drug fingolimod induces pore-like membrane defects, contributing to its antimicrobial activity

Multichannel Through‐Space Charge Transfer Triplet Photosensitizers for Rapid Visible‐Light Polymerization and High‐Fidelity 3D Printing

ABSTRACT Visible‐light‐driven polymerization offers unparalleled spatiotemporal control and energy efficiency, yet its practical performance is fundamentally constrained by the excited‐state dynamics of the photosensitizer. In this study, we report a class of ortho ‐positioned multi‐donor–acceptor molecules featuring multichannel through‐space charge transfer (TSCT) characteristics as highly efficient, heavy‐atom‐free triplet photosensitizers. By constructing a highly twisted three‐dimensional (3D) charge‐transfer network, these molecules achieve exceptional photophysical performance, including high intersystem crossing (ISC) quantum yields ( Φ ISC up to 0.86), microsecond‐scale triplet lifetimes, and an extraordinarily small singlet‐triplet energy gap (Δ E ST as low as 0.008 eV), while maintaining high triplet energies and strong visible‐light absorption. Benefiting from these attributes, the TSCT photosensitizers efficiently activate diphenyl ketone benzoyl oxime ester coinitiators via a triplet‐triplet energy transfer (TTEnT) mechanism, enabling rapid and well‐controlled acrylate polymerization under low‐intensity visible‐light irradiation. Importantly, this strategy enables, for the first time, the application of multichannel TSCT photosensitizers in digital light processing (DLP) 3D printing, allowing high‐resolution fabrication of complex 3D architectures under ambient conditions with excellent operational robustness and biocompatibility. This work establishes a versatile molecular platform for the rational design of organic triplet photosensitizers and advances visible‐light‐based precision manufacturing technologies.

CHDS: a boundary-oriented oversampling method for imbalanced data based on convex hull and Delaunay triangulation

Lactate-fueled H3K18 lactylation sustains ΔNp63α-dependent self-renewal in limbal epithelial stem cells

Click-Gelable and Self-Healing Organogels Based on Inorganic Sub-Nanowires

Correction: The spatial heterogeneity of soil physical and chemical properties and comprehensive fertility in the Leizhou Peninsula coast

A novel autopolysialylation activity of the ganglioside sialyltransferase ST8Sia5 regulates its secretion and enzyme activity

Optimized Octahedral Geometry and Hidden Rigidity of a <i>mer</i> -Tridentate N-Heterocyclic Carbene Ligand Enhance Luminescence of an Fe(III) Complex

AI agency drives college students’ entrepreneurial thinking through human sense of agency in human and ai symbiosis

Abstract As artificial intelligence (AI) increasingly penetrates education and entrepreneurial practice, cultivating students’ entrepreneurial thinking in a “human-AI symbiotic” environment has become a crucial issue in entrepreneurship education. Based on symbiotic agency theory and triadic reciprocal determinism, this study constructs a theoretical model of “AI agency—human sense of agency—entrepreneurial thinking,” using opportunity recognition and creativity as the core dimensions of entrepreneurial thinking to examine how AI agency is associated with college students’ entrepreneurial cognition. Based on a sample of 972 college students, the study employs a hybrid research method combining SLR, SEM, and fsQCA. The results show that: (1) AI agency is composed of three dimensions: cognitive support, interaction support, and action support, forming a stable structure of human-AI symbiotic environment in entrepreneurial learning contexts. (2) AI agency is positively associated with entrepreneurial thinking both directly and indirectly through the human sense of agency. (3) High-level entrepreneurial thinking is not associated with a single factor alone but with configurations of multiple conditions, with interaction support and sense of agency playing stable core roles. (4) Furthermore, creativity and opportunity recognition exhibit different generative logics. The study theoretically elevates AI from a tool to a technological partner and capability community in entrepreneurial learning, and provides insights for the design of AI instructional courses in entrepreneurship education.

Prenatal cannabinoid exposure alters excitation-inhibition balance through glutamate and GABA receptor-mediated signaling

Propane-CO ₂ Coupling Reaction over Isolated Cr Active Centers in the Beta Zeolite

mTOR signalling mediates the spinal osteoblast pathotype at the curve apex in adolescent idiopathic scoliosis

Abstract Adolescent idiopathic scoliosis (AIS) is associated with dysregulated bone remodelling, yet the molecular underpinnings remain unclear. To investigate site-specific osteoblast phenotypes at the spinal curve apex, we performed bulk RNA sequencing on primary matched osteoblasts isolated from the convex, concave, and non-curve regions of AIS patients. Principal component analysis revealed distinct transcriptional clustering by spinal site, independent of patient-specific factors. Differential expression analysis identified region-specific molecular profiles in convex and concave osteoblasts compared to non-curve controls, with the mTOR pathway being highlighted as one of the most dysregulated. Rapamycin, an mTOR inhibitor, reduced Alkaline phosphatase (ALP) activity, Osteoprotegerin (OPG) secretion, and mineralization, while modulating osteogenic gene expression, including sustained upregulation of RUNX2 and COL1A1 . In AIS patient-derived osteoblasts, rapamycin elicited pronounced inhibition of mTOR signalling and osteogenic activity in convex cells compared to control. Convex osteoblasts also showed elevated mTOR expression but reduced downstream translation-related signalling, suggesting dysregulated or uncoupled mTOR activity. Notably, mTOR expression level correlated with curve severity, reinforcing the link between mTOR dysregulation and AIS pathology. These findings identify mTOR signalling as a key regulatory pathway in AIS osteoblast dysfunction and highlight rapamycin as a potential, though complex, therapeutic candidate.

DNA methylation, nucleic acid structure, and rett mutations tune MeCP2 binding affinity and cooperativity

Geochemical environment affected by acid mine drainage: a case study of trace and rare earth elements of Colorful Lakes in Wieściszowice (Western Sudetes Mts., Poland)