Browse Articles

Distinct roles of claws and adhesive pads in honey bees determine their adhesive performance under varying surface roughness conditions through a dual-mode synergistic adhesion mechanism

Surface roughness is a critical factor that affects surface adhesion in bees. Investigating the mechanisms underlying surface adhesion in bees on substrates with varying surface roughness levels provides a theoretical basis for designing bioinspired adhesives and micro-climbing robots. In this study, a specialized adhesion measurement device was developed to compare the adhesive forces applied on substrates with different roughness levels by intact bees and by those whose adhesive pads have been removed. Moreover, a contact model for adhesion between the claw tips and substrate particles and a liquid bridge model for adhesion between the adhesive pads and substrate surfaces were established to analyze the distinct roles of claws and adhesive pads, respectively, under different surface roughness conditions. The results revealed that on surfaces with roughness values below 3.2 μm, the adhesive pads secreted liquid to form liquid bridges, increasing contact area and adhesive force, thereby dominating the adhesion process. As the surface roughness increased, the contribution of the adhesive pads diminished, whereas the mechanical interlocking effect of the claws became relatively more pronounced. When the surface roughness exceeded 36 μm, the irregularity of substrate particles enhanced the interlocking effect of the claws, making the force generated by the claw tip the dominant adhesion force. Thus, the integration of the contact and liquid bridge models revealed the synergistic effects of mechanical interlocking and liquid bridge mechanisms on improvement in surface adhesion in bees.

Highly Active Pt‐Fe Catalysts Towards CO Preferential Oxidation with an Ultra‐Wide Temperature Window

Abstract Preferential oxidation of CO in H 2 (CO‐PROX) is a promising solution to remove the residual CO in the feed stream to avoid Pt poisoning in proton‐exchange‐membrane fuel cells (PEMFCs), in which the development of high‐efficiency catalysts with a wide temperature window remains a great challenge. Herein, we report a Fe(OH) x modified Pt clusters (∼1.6 nm) catalyst supported on MgAlO x (denoted as MA) derived from PtFeMgAl‐layered double hydroxides (PtFeMgAl‐LDHs) precursor, which is featured with abundant Pt δ + –(OH) x –Fe 3+ interfacial sites. Impressively, the optimal catalyst Pt‐Fe(OH) x /MA exhibits exceptional catalytic performance towards CO‐PROX, which can completely remove CO in a H 2 ‐rich stream with an ultra‐wide full CO conversion window (25°C−225 °C) at a rather high space velocity (130 000 mL g cat −1 h −1 ). The mass‐specific activity reaches to 9.09 mol CO g Pt −1 h −1 at 25 °C, which is preponderant to the state‐of‐the‐art catalysts. In addition, a 240 h stream‐on‐line test over Pt‐Fe(OH) x /MA shows a satisfactory stability. A comprehensive investigation based on in situ experimental studies and theoretical calculations reveals that the –OH group at the Pt δ + –(OH) x –Fe 3+ interfacial site is easily bound to the linearly‐adsorbed CO at the adjacent Pt δ + site to form carboxylate intermediate, followed by its decomposition to CO 2 . Meanwhile, the generated coordination unsaturated Fe 2+ site facilitates the activation cracking of O 2 molecule without energy barrier. A structure design strategy of interfacial synergistic catalysis towards CO‐PROX is proposed in this work, which shows fundamental significance and application prospects in hydrogen purification.

Intraindividual, intraspecific, and interspecific variation shapes natural selection and its detection in two convergently-evolved lizard species

Much of our understanding of how natural selection operates comes from studies of highly heritable traits presumed to vary little within individuals. Here we show that intraindividual (within-individual) phenotypic variation is an important source of intraspecific variation, shaping both natural selection and its detection in wild, open populations. We employed a multi-year capture-mark-recapture (CMR) study of two lizard species (Sceloporus cowlesi and Holbrookia maculata) at the ecotone between the white gypsum dunes at White Sands National Park and the surrounding dark Chihuahuan desert soils. Unlike many CMR studies examining selection on morphology, we measured individuals’ traits at each capture. We found that our inferences into which traits were under selection depended on which measurement instance we used (first, last, or median measurement of all measurements of a given trait), and, therefore, the degree of intraindividual variation within each trait. We present a contingency analysis to facilitate assessing when traits are under selection, when they are not, and when intraindividual variation complicates these inferences. Beyond these conceptual advances, our work has implications for the White Sands system, a model system for repeated evolution. In particular, both lizard species experience different selection regimes within the same ecotonal habitat, despite both showing convergent evolution in dorsal blanching on White Sands.

Force-dependent development of the myodural bridge in rats: The impact of Integrin α7

The myodural bridge (MDB) represents specialized fibrous structures establishing connectivity between suboccipital musculature and the spinal dura mater (SDM). The suboccipital muscles, ligaments, and myodural bridge fibers together form a functional unit known as the myodural bridge complex (MDBC). Mechanical stress from suboccipital muscles may contribute to MDB maturation. Integrin α7 (ITGA7) is critical for skeletal muscle attachment to connective tissues, and is involved in the transmission of lateral and longitudinal forces in skeletal muscle. Given the muscle force transmission characteristics of ITGA7 and the dependence of MDB development on force transmission, we hypothesized that ITGA7 serves as a crucial link between RCDmi and the MDB it emits, and may involve in the development of MDBC. To test this, neonatal Sprague-Dawley (SD) rats were randomly allocated to shRNA-ITGA7, shRNA-NC control, lentiviral vectors were injected into the dorsal atlanto-occipital interspace. ITGA7 suppression significantly impaired MDB development and maturation, manifesting as disrupted fiber assembly and RCDmi muscle dystrophy. Ultrastructural analysis revealed disorganized collagen fiber architecture and an abundance of fibroblasts, indicative of immature collagen fibers, further corroborated by Picrosirius red staining. Additionally, ITGA7 knockdown resulted in diminished RCDmi muscle force and altered ECM-related gene expression profiles. A key finding of our study is the importance of ITGA7 as a direct molecular link between suboccipital muscles and MDB, suggesting that mechanical forces from suboccipital musculature fundamentally influence MDB differentiation and maturation. These findings substantiate MDB’s role in force transmission to the SDM and by extension, advance our understanding of the molecular mechanisms underlying MDB development and its physiological significance.

Comprehensive performance evaluation of four chemiluminescence immunoassays for detecting vitamin D deficiency across diverse clinical conditions

Background/Objectives Vitamin D deficiency is a significant global health concern, requiring accurate diagnosis. This study evaluates the performance of four chemiluminescent immunoassay (CLIA) platforms; Snibe, Roche, DiaSorin, and Architect for vitamin D measurement. Methods A total of 345 serum samples, selected to represent a broad range of vitamin D levels and diverse health conditions, including pregnancy, chronic kidney disease, and osteoporosis, were analyzed using four platforms. Diagnostic metrics, including sensitivity, specificity, and overall percent agreement (OPA), were calculated. Spearman’s rank correlation and bias assessment were performed to evaluate inter-assay agreement. Results Spearman’s rank correlations were strong to very strong across the platforms, ranging from r = 0.924 to r = 0.969, reflecting high inter-assay concordance. Pairwise comparisons indicated that Snibe demonstrated high specificity (98–99%) and strong agreement with DiaSorin (κ = 0.91), while DiaSorin maintained a favorable balance between sensitivity (86–98%) and specificity (94–99%). Roche showed consistent diagnostic characteristics, with sensitivity ranging from 93–99% and specificity from 85–96%. Architect exhibited high sensitivity (97–99%) but relatively lower specificity (81–92%). Conclusions All platforms demonstrated robust diagnostic performance. Snibe showed notably high specificity, while DiaSorin offered balanced sensitivity and specificity. These findings underscore the relative strengths of each platform and support their use in clinical evaluation of vitamin D status.

Highly Efficient Singlet Oxygen Production in a Cascade Photoelectrocatalytic System for Water Decontamination

Abstract Singlet oxygen (¹O₂) demonstrates great potential for selective wastewater detoxification, which raises the appeal to achieve a controllable, mild, and efficient generation of this reactive species for water decontamination. Herein, we present a novel cascade photoelectrocatalytic (PEC) system operated via the interaction between the photoanodic and cathodic reactions without the addition of chemical precursors, realizing highly efficient ¹O₂ production (79.7 µmol L −1 min −1 ) and low energy consumption (0.052 kWh m −3 ‐log) for antibiotic degradation. The enhanced 1 O 2 production is proven to benefit from the synergistic effect of multiple activation pathways under PEC excitation. With the combined action of both the built‐in electric field and external electric field, the holes in the Z‐scheme heterojunction photoanode are maximally retained, and electrons are transferred to cathode to undergo the oxygen reduction reaction (ORR), leading to the production of the crucial reactive oxygen species as intermediates. The occurrence of a cascade reaction is initiated by electrocatalytic 2e − ORR on the cathode and terminated by superoxide species oxidation by holes on the photoanode. The hole‐involved 1 O 2 generation pathway circumvents the thermodynamically unfavorable process of traditional 1 O 2 generation. This work highlights a new PEC route for highly efficient 1 O 2 generation, making it a potential application in more effective environmental remediation.

Graph theory-based analysis of functional connectivity changes in brain networks underlying cognitive fatigue: An EEG study

Objective This investigation was designed to analyze alterations in functional connectivity across brain networks associated with cognitive fatigue through electroencephalogram (EEG) data analysis. Through the application of both global and local graph-theoretical metrics to characterize the topology of brain networks, this study establishes a conceptual framework supporting enhanced detection of cognitive fatigue manifestations while facilitating examination of its neurophysiological substrates. Methods The study cohort comprised neurologically intact individuals aged 20–35 years, recruited from Beijing Rehabilitation Hospital, Capital Medical University between February 6 and September 30, 2024 for participation in a cognitive fatigue induction task. Following acquisition of written informed consent, data before and after the task were obtained, including both subjective fatigue assessments using the Visual analog scale for fatigue (VAS-F) scores and EEG data. The preprocessed EEG signals were segmented into three frequency bands: θ (4–8 Hz),α (8–13 Hz), and β (13–30 Hz). To determine the frequency band exhibiting maximal sensitivity to cognitive fatigue, cross-band comparative power spectral density (PSD) was implemented. The selected frequency band subsequently served as the basis for weighted Phase Lag Index (wPLI) computation, yielding a functional connectivity matrix derived from wPLI measurements. Network topology was evaluated through application of five global graph theory metrics (global efficiency [Eg], local efficiency [Eloc], clustering coefficient [Cp], shortest path length [Lp], and small-world property [Sigma]) complemented by two local graph theory metrics (nodal efficiency [NE] and degree centrality [DC]). This analytical framework enabled systematic comparison of connectivity patterns and topological characteristics between before and after cognitive fatigue states. Results Statistical analysis revealed significant post-fatigue elevations in global average PSD across all examined frequency bands: α (p < 0.001), θ (p < 0.001), and β (p = 0.004). The α band demonstrated the most pronounced effect size (Cohen’s d = 4.23, r = 0.90). Topological analysis of α-band wPLI networks showed enhanced Eg (p = 0.005), Eloc (p < 0.001), and Cp (p < 0.001), whereas Lp displayed significant reduction (p = 0.005). Regional analysis revealed preferential enhancement of NE, particularly in central and anterior cortical regions. Conclusion The experimental data indicated that α-band activity exhibited the highest sensitivity to cognitive fatigue induced by the sustained Stroop task, establishing a framework for accurate identification of fatigue states. Cognitive fatigue compensatory mechanisms manifested as concurrent improvements in both local and global neural information processing efficiency. Although such adaptive reorganization may compromise overall network efficiency, these findings implied an inherent balance between adaptive network reconfiguration and system efficiency. These results elucidated novel neurophysiological mechanisms underlying cognitive fatigue, substantially advancing our understanding of brain network dynamics during prolonged cognitive demand.

Premature termination of DNA Damage Repair by 3-Methyladenine potentiates cisplatin cytotoxicity in nasopharyngeal carcinoma cells

3-Methyladenine (3-MA) is widely recognized as a PI3K inhibitor involved in autophagy regulation. However, it is also a byproduct of DNA damage repair, and its role in modulating DNA damage response (DDR) mechanisms remains largely unexplored. Cisplatin (CDDP), a cornerstone chemotherapeutic agent for nasopharyngeal carcinoma (NPC), exerts its cytotoxic effects by inducing DNA damage in tumor cells. This study investigates the combined effects of CDDP and 3-MA on NPC cells. Cell viability and the half-maximal inhibitory concentration (IC50) were assessed using the Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was employed to analyze cell cycle distribution, mitochondrial membrane potential (MMP) alterations, and apoptosis. γ-H2AX foci formation and morphological changes were examined via fluorescence microscopy, while Western blotting was used to evaluate proteins associated with the DNA damage response. The combination treatment significantly reduced cell viability and lowered the IC50 compared to CDDP alone. While both treatments induced Sub-G1 phase arrest, the combination resulted in greater MMP loss and apoptosis. Western blot analysis further revealed that 3-MA enhanced CDDP cytotoxicity by suppressing ATM/ATR/p53-mediated DNA damage repair and promoting apoptotic signaling. These findings suggest that 3-MA sensitizes NPC cells to CDDP by disrupting DNA repair processes, offering a promising therapeutic strategy.

Multi-scale feature pyramid network with bidirectional attention for efficient mural image classification

Mural image recognition plays a critical role in the digital preservation of cultural heritage; however, it faces cross-cultural and multi-period style generalization challenges, compounded by limited sample sizes and intricate details, such as losses caused by natural weathering of mural surfaces and complex artistic patterns.This paper proposes a deep learning model based on DenseNet201-FPN, incorporating a Bidirectional Convolutional Block Attention Module (Bi-CBAM), dynamic focal distillation loss, and convex regularization. First, a lightweight Feature Pyramid Network (FPN) is embedded into DenseNet201 to fuse multi-scale texture features (28 × 28 × 256, 14 × 14 × 512, 7 × 7 × 1024). Second, a bidirectional LSTM-driven attention module iteratively optimizes channel and spatial weights, enhancing detail perception for low-frequency categories. Third, a dynamic temperature distillation strategy (T = 3 → 1) balances supervision from teacher models (ResNeXt101) and ground truth, improving the F1-score of rare classes by 6.1%. Experimental results on a self-constructed mural dataset (2,000 images,26 subcategories.) demonstrate 87.9% accuracy (+3.7% over DenseNet201) and real-time inference on edge devices (63ms/frame at 8.1W on Jetson TX2). This study provides a cost-effective solution for large-scale mural digitization in resource-constrained environments.

Inwardly Directed Linker Propagation: Constructing 3D Covalent Organic Frameworks for Efficient H ₂ O ₂ Photosynthesis

Abstract The limited design strategy of three‐dimensional covalent organic frameworks (3D COFs) greatly restricts their structural diversification and potential applications. Herein, we propose an inwardly directed linker propagation strategy for the targeted assembly of 3D COFs (COF‐IN‐1 and COF‐IN‐2) and compare them with outwardly directed expanded COFs (COF‐OUT‐1 and COF‐OUT‐2). COF‐OUTs exhibit planar heteroporous 2D frameworks with cpt topology, while COF‐INs engineer controlled triple entanglements into networks, forming 3D frameworks with acs topology. Moreover, the COFs assembled via inwardly directed linker propagation effectively enhanced the production of H 2 O 2 photosynthesis. To demonstrate the application potential, a biphasic fluid system was constructed for continuous H 2 O 2 photosynthesis and extraction. This work not only expands the design strategy for achieving 3D COFs but also demonstrates that the dimensional regulation of frameworks and tuning of applications can arise from different expanding directions of the linkers.

Correction: Effects of gender sensitive language in job listings: A study on real-life user interaction

Energetics Modulation for Efficient and Stable n–i–p Perovskite Solar Cells

Abstract The operational stability of n–i–p perovskite solar cells (PSCs) under heat, air, and humidity has notably improved over recent years. Yet, performance degradation under light and voltage bias remains a concern for their commercial deployment. One of the main causes of such degradation relates to mobile ions in the perovskite film, which can trigger ion migration and self‐accelerating chemical degradation. Here, we propose an energetics modulation strategy by developing the electron‐withdrawing pyridinecarboxaldehyde oxime (PO) ligand for FAPbI 3 ‐based perovskites. The introduction of PO ligands increases the ionization potential of the perovskite, inhibiting the generation of mobile ions during the crystallization process and subsequent device operation. Furthermore, this additive promotes the reaction between PbI 2 and organic salts, which can help to regulate the energy level of perovskite and facilitate charge transport to the contact stacks. As a result, the optimized n–i–p PSCs exhibit a high efficiency of 26.13% and maintain over 88% of their initial efficiency after 1000 h maximum power point (MPP) tracking test under 1 sun illumination. This work underlines the importance of energetics modulation for inhibiting intrinsic perovskite degradation that cannot be achieved by mere device encapsulation.

Correction: Dynamic imaging of myelin pathology in physiologically preserved human brain tissue using third harmonic generation microscopy

Electrochemical Allene C─H Functionalization via Carbanion Sampling

Abstract Functionalization of C─H bonds represents a direct and practical avenue to upgrade simple organic molecules to value‐added products, whereas the reaction selectivity is largely governed by the acidity and bond dissociation energy (BDE) of C─H bonds. Developing a novel strategy to break these constraints is highly desirable, as it would open a new horizon for conventionally challenging molecules. Herein, we disclosed a carbanion sampling strategy that enables unconventional selectivity in the allene C(sp 2 )─H functionalization harnessing chromium‐catalyzed hydrogen evolution. The electrochemical protocol provides in situ access to diverse allene carbanions and facilitates a dynamic carbanion sampling process to give thermodynamically unfavored products. 1,3‐Disubstituted allenes were precisely functionalized at the less acidic and stronger C(sp 2 )─H site to yield abnormal site‐selective allene products, while the 1,1‐substituted allenes proceeded isomerization to deliver functionalized alkynes. All of the products presented in this work are unprecedented and exhibit remarkable versatility in late‐stage derivatization. The superiority of the carbanion sampling strategy was demonstrated in the convergent synthesis of functionalized allenes from alkyne or mixed substrates. More importantly, we conducted a series of density functional theory (DFT) calculations and control experiments to rationalize the unconventional selectivity.

Correction: Fish community composition in the tropical archipelago of São Tomé and Príncipe

Giant Birefringence and Solar‐Blind Ultraviolet Transmission by Coordination‐Induced Assembly of π‐Conjugated Pyridine–Carboxylate

Abstract Giant birefringent crystal with large bandgap is of paramount importance for modern optical devices but simultaneous achievement of giant birefringence and large bandgap is a great challenge stemming from their inherent contradictory relationship according to Kramers‒Kronig equation. Herein, an organic–inorganic hybrid uniformly‐stacked 2D crystal [Be 2 (μ‐OH) 2 (C 7 H 3 NO 4 )(H 2 O)]·H 2 O ( I ) was successfully synthesized by a molecular crystal engineering involving hydrogen bond synthons. Layered I features new [Be 2 O 2 N(μ‐OH) 2 (H 2 O)] ∞ helical chain composed of Be II tetrahedral coordination, and the strong covalent Be II cations coordinate with the O and N atoms on birefringence‐active π‐conjugated (C 7 H 3 NO 4 ) 2− organic groups with optimal spatial arrangement. As a result, I demonstrates the largest birefringence of 0.6 in the solar‐blind UV spectral region, with large bandgap of 4.75 eV and short UV absorption edge of 261 nm. First‐principles calculations and structural analyses uncover that the superior optical properties mainly originate from collective effects of highly‐active (C 7 H 3 NO 4 ) 2− groups, distorted Be‐tetrahedral units, and their uniform stacking. This work not only provides a potential solar‐blind UV birefringent crystal for rapidly increasing number of optical applications but also a new chance for the rational design of wide UV giant birefringent crystals.

Barriers and facilitators to palliative care service utilization in Ethiopia: A qualitative systematic review, 2025

Introduction Palliative care is a crucial component of end-stage disease management, but its utilization remains low in low- and middle-income countries, such as Ethiopia. This is due to various systemic, social, and policy barriers. Understanding these contextual factors is crucial for developing effective interventions and policy frameworks. This study aimed to explore and synthesize the barriers and facilitators to palliative care service utilization in Ethiopia using a qualitative systematic review approach. Methods This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Qualitative Synthesis (PRISMA-Q) guidelines, employing a qualitative systematic design. A comprehensive search was conducted across various databases using tailored keywords and MeSH terms up. The database was searched for every article published on palliative care services up to March 10, 2025, and was updated continuously until it was sent for publication. The data was extracted from March 11–20 and later analyzed from March 21–30, and the report generation till April 10, 2025. Thematic synthesis was used to analyze findings and the Grading of Recommendations Assessment, Development, and Evaluation Confidence in the Evidence from Reviews of Qualitative research approach was employed to assess the confidence of evidence. Results Six studies met the inclusion criteria, encompassing diverse Ethiopian healthcare settings and stakeholders. Five major barriers were identified: policy and governance gaps, health system challenges, knowledge and training deficits, sociocultural and economic constraints, and poor collaboration. In contrast, five facilitators emerged: strong community and family support, intrinsic healthcare provider motivation, integration of palliative care into education, holistic care models, and stakeholder engagement. High confidence was assigned to four themes, underscoring their significance and applicability. Conclusion The underutilization of palliative care in Ethiopia stems from intertwined structural, educational, and sociocultural challenges. However, promising facilitators exist that can guide policy reform and intervention design. Addressing these barriers through improved policies, workforce development, and community engagement is imperative for ensuring equitable access to quality palliative care services.

Neuroimaging insights into recent suicide attempters utilizing the raven task

Background Understanding brain function in individuals who have recently attempted suicide is critical for improving diagnosis and treatment strategies. This study aimed to examine neural activity patterns in such individuals (who had attempted suicide 1–4 weeks before the study) using functional magnetic resonance imaging (fMRI) and the General Linear Model (GLM). Methods Sixty participants were recruited and categorized into three groups: individuals with a recent suicide attempt and Major Depressive Disorder (SA + MDD), individuals with Major Depressive Disorder without a suicide attempt (MDD), and healthy controls (HC). Participants performed the Raven task, consisting of 24 trials with a 25-second time limit for each item. Brain activity was analyzed to identify regional differences among groups using ANOVA, followed by Tukey’s post-hoc pairwise comparisons. Results Compared to the MDD and HC groups, the SA + MDD group exhibited significantly reduced activation in the left medial superior frontal cortex (SFC), left anterior cingulate cortex (ACC), and left precentral gyrus. Positive correlations were observed between the Scale for Suicidal Ideation scores and activity in the medial SFC and ACC, whereas a negative correlation was found with precentral gyrus activity. While task accuracy did not significantly differ among the groups, the SA + MDD group demonstrated significantly shorter response durations. Conclusion Individuals with recent suicide attempts show diminished activation in key left-hemispheric regions involved in cognitive control and problem-solving, including the medial SFC, ACC, and precentral gyrus. These neural deficits may impair decision-making and problem-solving abilities, particularly when compounded by hopelessness and a diminished sense of purpose, potentially contributing to increased suicide risk.

Correction: Accelerating automatic model finding with layer replications case study of MobileNetV2

NPA6: A Molecule for Non‐Covalently Linked Radical‐Enhanced ISC and High‐Performance Photopolymerization with Afterglow

Abstract To harness electron spin exchange for radical‐enhanced intersystem crossing (ISC), a typical strategy involves covalently attaching stable radicals to chromophores. Here, we introduce NPA6, synthesized by attaching heptanamide to N , N ‐diphenylnaphthalen‐1‐amine (NPA). NPA6 maintains the phosphorescent properties of NPA and exhibits unique photo‐generated radical behavior that is absent in NPA. These radicals can further adsorb neutral molecules to form supramolecular assemblies. Compared to pristine NPA6, these assemblies exhibit nearly complete NMR proton signal suppression in the aromatic region, enhanced absorption near 400 nm, and reduced fluorescence intensity. Phosphorescence measurements at 77 K reveal stronger phosphorescence in the assemblies, with delayed excitation spectra confirming phosphorescence originating exclusively from neutral molecules, indicating successful noncovalent radical‐enhanced ISC. As a photosensitizer in N , N ‐dimethylacrylamide polymerization, NPA6 achieves nearly 100% conversion at 100 ppm under 410 nm light and ambient conditions, exhibiting superior polymerization performance. Additionally, its afterglow makes it suitable as an in situ quality indicator for transparent coatings, suggesting its potential applications in photolithography.