Crystalline bacterial cell surface layers (S-layers) are self-assembling protein lattices that constitute the outermost envelope structure of many Bacteria and most Archaea. Beyond their classical role as cell surface components, S-layers are increasingly recognized as programmable, two-dimensional biological materials that combine nanometer-scale precision, defined porosity, and exceptional physicochemical properties. In this review, we synthesize current understanding of S-layer architecture, assembly, and functionalization to position them as a unifying platform for nanobiotechnology and synthetic biology. We highlight how their intrinsic self-assembly and genetic engineerability enable the design of ordered biomolecular interfaces with applications ranging from molecular sieving, biosensors, biomineralization, and nanoscale patterning. Engineered S-layer fusion proteins allow the modular and spatially controlled display of functional domains, bridging bottom-up materials design with biological complexity. Beyond their technological relevance, S-layers play underappreciated roles in host-microbe interactions, where their structural regularity and surface accessibility shape immunogenicity and cellular recognition, with implications for vaccine development, targeted delivery, and microbiome engineering. We argue that overcoming current limitations in scalable production, stability, and system integration will be key to unlocking the full potential of S-layers as genetically programmable, bio-inspired interfaces, enabling a new class of adaptive nanomaterials and advancing the design principles of synthetic biological systems.
Neocortical synapses are highly dynamic during brain development, undergoing formation, elimination, and maturation before acquiring properties that support adult cognition. Individual neocortical regions develop at different ages and individual layers within these regions contain distinct neuronal subtypes that process unique patterns of local and long-range synaptic input. To better understand the development of the cortical hierarchy we explored the laminar maturation of glutamatergic synapses across cortical regions of male and female mice. Synapse maturation was associated with the upregulation of the postsynaptic density protein PSD95. This maturation occurred in a region- and layer-specific manner - layers associated with feedforward pathways develop earlier, while layers associated with higher-order circuits develop later. Our findings highlight adolescence as an important period for the cortex-wide maturation of synapses in cortical layer 1, synapses known to receive top-down feedback from higher-order cortices. We propose that this delayed adolescent maturation of top-down input represents a global signature of cortical development and seemingly acts as the final stage of outside-in brain maturation.Significance statement Our findings provide a high-throughput analysis of the postnatal development of glutamatergic synaptic proteins across the neocortical hierarchy. We highlight key differences in the maturation of higher cognitive areas and sensory motor areas. We also observe the delayed and protracted maturation of cortical layer 1, which develops in a neocortex-wide manner during adolescence. Using analysis of synaptic puncta and computational modelling we explore the synaptic mechanisms that underlie these changes. This work highlights adolescence as an important period for the maturation of top-down inputs to layer 1, which may play an important role in the emergence of adult-like cognition during this developmental stage.
Long-term fertilization is widely recognized as an effective strategy for enhancing soil fertility and carbon sequestration; however, its depth-dependent impacts on soil biogeochemical processes remain insufficiently understood. Here, the responses of soil physicochemical properties, carbon and nitrogen pools, microbial biomass, and enzyme activities to different fertilization regimes (control, chemical fertilizer, manure, and their combination) were investigated across a 0-100 cm soil profile in apple orchards during 2023, and 2024. The results indicated that most soil properties exhibited significant depth-dependent patterns (p < 0.05-0.001), with soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), available potassium (AK), microbial biomass, and enzyme activities decreasing significantly with depth, while soil pH and water content increased. Compared to chemical fertilizer alone, combined manure and chemical fertilizer (MCF) significantly increased SOC, TN, AP, and AK across both surface and subsurface layers (p < 0.05), whereas chemical fertilizer showed no significantly increased SOC, TN, AP, and AK across both surface and subsurface layers (p < 0.05), whereas chemical fertilizer showed no significant improvement below 40 cm. These changes have driven significant increases in microbial biomass carbon and nitrogen, as well as enzyme activities involved in carbon (β-glucosidase), nitrogen (N-acetyl-β-D-glucosaminidase), and (alkaline phosphatase) cycling under MCF (p < 0.01). In contrast, mineral nitrogen forms showed weaker and partially non-significant associations with other soil variables. Notably, multivariate and network analyses revealed that integrated fertilization significantly strengthened the coupling among soil carbon, nitrogen, microbial biomass, and enzyme activities, particularly in 2024, indicating enhanced system stability. Overall, combined organic-inorganic fertilization promotes a vertically extended and functionally resilient soil system, providing new insights into sustainable nutrient management and soil health in orchard ecosystems.
Horseshoe kidney is an uncommon congenital fusion anomaly that can make renal tumor surgery especially challenging because of altered rotation, limited mobility, variable vascular supply, and an unpredictable collecting system (1-7). This video presents a robot-assisted partial nephrectomy for a high-complexity renal tumor in this setting. A 33-year-old man, with ECOG 0 and no relevant comorbidities, was diagnosed with a 7.5-cm solid renal mass in the central posterior portion of the left moiety of a horseshoe kidney. The lesion had a RENAL score of 10p. Contrast-enhanced computed tomography and three-dimensional reconstruction were used to understand the relationship between the tumor, aberrant vessels, renal hilum, and collecting system, supporting the decision to attempt nephron-sparing surgery (5, 8). Surgical technique and results: The procedure was performed through a transperitoneal robotic approach with the patient in right lateral decubitus using the Da Vinci Si platform. Port placement followed a standard renal robotic configuration, with a paramedian supraumbilical camera port, three robotic working ports along a craniocaudal lateral axis, a caudal fourth-arm port, and two medial assistant ports for suction, exposure, and support during renorrhaphy. After exposure of the horseshoe kidney and left hilar dissection, two arterial branches and one renal vein were identified. Tumor excision was performed under vascular control, with 20 minutes of warm ischemia and no collecting system opening, followed by two-layer absorbable renorrhaphy with adjunctive hemostatic agents. The operative time was 150 minutes. No transfusion, conversion, drain placement, or relevant immediate complication occurred. The urinary catheter was removed after 24 hours, and the patient was discharged 72 hours after surgery. Pathology showed clear cell renal cell carcinoma, Fuhrman grade 3, pT2N0M0, with negative surgical margins. During 12 months of oncologic follow-up, renal function remained stable and semiannual imaging showed no evidence of recurrence. Contemporary video reports have also emphasized the feasibility of advanced robotic renal surgery and complex partial nephrectomy strategies in selected patients (9, 10). In a carefully selected patient, robot-assisted partial nephrectomy supported by three-dimensional planning was feasible for a complex renal tumor in a horseshoe kidney, with negative surgical margins, preserved renal function, and no recurrence during 12 months of follow-up.
Mucins are highly glycosylated proteins, a subset of which form the structural basis of mucus barriers at mucosal surfaces. In the gastrointestinal tract, the secreted gel-forming mucin MUC2 is the principal component of the intestinal mucus layer and plays a critical role in maintaining host-microbiota homeostasis. MUC2 undergoes extensive post-translational glycosylation mediated by numerous glycosyltransferases, producing a dense network of O- and N-linked glycans that regulate mucus structure, microbial interactions, and barrier function. Disruption of mucus integrity has been implicated in a range of diseases including infection, inflammation, and cancer. Accurate visualization and quantification of mucus architecture are therefore essential for understanding mucus biology and its role in disease pathogenesis. Histological analysis remains the most accessible approach for studying mucus structure in situ. Recent work has revealed that the inner (barrier) layer can be subdivided into two distinct sublayers (b1 and b2) with different cellular origins and glycan compositions. These structural features necessitate analytical approaches capable of quantifying mucus thickness, spatial organization, and microbial proximity with high reproducibility. Here we describe a set of complementary workflows for the visualization and quantitative analysis of intestinal mucus. These include brightfield histochemical staining using Alcian Blue, fluorescence lectin labeling to resolve mucus sublayers, and combined mucin-bacterial fluorescence in situ hybridization for confocal imaging. In addition, we present automated image analysis pipelines implemented in ImageJ/Fiji for reproducible quantification of mucus thickness and spatial structure. Together, these approaches provide a practical framework for studying mucus barrier biology and mucus-microbe interactions in health and disease.
Multiple sclerosis (MS) is increasingly recognized across Gulf Cooperation Council (GCC) countries, where rising disease burden intersects with distinctive ancestry, family structure, consanguinity patterns, vitamin D deficiency, rapid environmental transition, and an unevenly developed genetic literature. Most global MS genetic models have been derived from European-ancestry datasets and may not fully capture susceptibility patterns, allele frequencies, familial structure, or gene-environment interactions in Arabian Gulf populations. A regionally focused synthesis is therefore needed, while recognizing that the available GCC evidence remains too limited, heterogeneous, and insufficiently replicated for conventional pooled meta-analysis. To map and critically synthesize available HLA, non-HLA, vitamin D pathway, transcriptomic, biomarker, familial, registry-related, and emerging mitochondrial evidence relevant to MS genetic and molecular susceptibility in GCC populations, and to define research priorities that could support future precision-neurology approaches. A PRISMA-ScR-informed scoping review and narrative evidence synthesis was conducted. PubMed, Embase, Scopus, Web of Science, Cochrane Library, and selected regional sources were searched for publications from January 2000 to February 2026, with an update before resubmission in June 2026. Eligible sources included GCC-based MS studies reporting HLA, non-HLA SNP, transcriptomic, serum biomarker, vitamin D pathway, familial, registry, or molecular evidence relevant to MS susceptibility or disease biology. Study-level effect estimates were extracted when available. No pooled meta-analysis was performed because repeated variant-level data across independent GCC cohorts were unavailable for most loci. Fourteen studies were included in the scoping synthesis; four provided directly extractable study-level effect estimates. The available evidence suggests, but does not prove, that MS susceptibility in GCC populations may be heterogeneous and not fully explained by Western-derived HLA-DRB1×15:01-centered models. Bahrain contributes HLA and transcriptomic/biomarker evidence, including inflammatory molecular signals involving IL-1RA, OASL, TNF-AIP6, CLC, DOCK4, and TMEM66 that require prospective validation. Saudi Arabia contributes familial and registry-based observations, with exploratory mitochondrial studies representing an additional future-oriented non-HLA research layer. Kuwait provides the most extractable non-HLA replication and vitamin D pathway data, including immune, metabolic, vitamin D receptor, and vitamin d-binding protein signals. Qatar, the United Arab Emirates, and Oman remain underrepresented in accessible primary MS genetic literature. Across all layers, the evidence is biologically informative but constrained by small cohorts, single-country designs, incomplete extractability, limited replication, and heterogeneous methods. Importantly, transcriptomic, biomarker, familial, registry, and mitochondrial findings were interpreted separately from inherited DNA-level association studies to avoid overstating clinical readiness or combining biologically related but methodologically distinct evidence types. GCC MS genetics should be interpreted as an emerging, fragmented, and hypothesis-generating field rather than a mature meta-analytic evidence base. Its value lies in clarifying evidence layers, identifying reproducibility gaps, and defining the infrastructure needed for future regional validation. Harmonized GCC registries, high-resolution HLA typing, non-HLA genotyping, vitamin D phenotyping, family-structured recruitment, biomarker validation, biobanking, mitochondrial substudies, ancestry documentation, transparent allele/genotype reporting, and registry-linked longitudinal outcomes could support future precision-neurology research without implying current readiness for routine genetic risk prediction or treatment selection, or individualized therapeutic stratification in routine clinical practice across the Arabian Gulf at present.
Scalable production of high-quality 2D nanosheets remains challenging because existing top-down and bottom-up methods typically face a trade-off between material quality, yield, and cost. Here, we report the seconds-scale (~12 s) production of high-quality 2D crystals via polycyclic aromatic hydrocarbon radical anion (PAH•-)-mediated organoalkali intercalation. The tunable reduction potential and electron-transfer capability of PAH•- enable ultrafast alkali-ion intercalation within seconds in the stable potential of layered hosts. For graphite, sodium naphthalenide (Na-Naph) forms a stage-1 graphite intercalation compound in only 1 s, and subsequent hydrolysis-driven exfoliation in 11 s yields graphene with >88% yield and >50% single-layer ratio, with a negligible increase in defect density (ID/IG ratio from ~0.10 to ~0.11). This strategy is further extended to the exfoliation of few-layer (3-5 layers) transition-metal sulfides, selenides, and tellurides while preserving their intrinsic crystal phases. This work establishes a practical, high-yield route for rapid intercalation-driven exfoliation, offering a scalable platform for manufacturing high-quality 2D crystals.
Bortezomib, a first-in-class proteasome inhibitor, has significantly transformed the therapeutic landscape of multiple myeloma (MM). Despite its clinical efficacy, both intrinsic and acquired resistance limit its long-term success. This review synthesizes current knowledge regarding molecular determinants of bortezomib sensitivity and resistance, with a focus on p53, Ras signaling, mTOR pathway activity, Wee1 kinase, and long non-coding RNAs (lncRNAs). p53 functions as a key mediator of bortezomib-induced apoptosis, and its loss or mutation blunts pro-apoptotic signaling. Aberrant Ras activation promotes pro-survival pathways that counteract proteotoxic stress, while mTOR signaling buffers metabolic and translational stress to support cell survival under bortezomib pressure. Wee1 kinase extends the G2/M checkpoint, granting MM cells time to repair DNA and mitigate proteotoxicity, thereby reducing sensitivity to bortezomib. In parallel, lncRNAs orchestrate multiple layers of resistance through miRNA sponging, epigenetic remodeling, metabolic rewiring, and intercellular transfer via exosomes. Each determinant contributes uniquely to cellular adaptation, stress tolerance, and survival under proteasome inhibition. Integrating these pathways reveals a complex regulatory network where apoptosis and survival signals compete, ultimately shaping drug response. We further discuss therapeutic implications, biomarker development, and emerging strategies, including RNA-based therapies, multi-omics profiling, and rational drug combinations. By expanding mechanistic understanding, this review aims to guide the design of precision strategies to overcome bortezomib resistance in MM.
High-resolution, real-time tactile sensing is essential for robotic tasks that demand accurate, dynamic detection of contact morphology and pressure distribution, such as grasping and manipulation of delicate, slippery, or irregularly shaped objects. Existing technologies, however, face a fundamental trade-off between spatial resolution and response speed. Taxel-based sensors (e.g., capacitive, resistive, or piezoelectric) operate in real time but are intrinsically limited in resolution by taxel size, spacing, wiring, and cross-talk; even deep learning-based tactile super-resolutions rarely surpass ∼1 millimeter. Finer resolutions can be achieved with vision-based tactile sensors using just a camera, although the computation required to transform raw images into three-dimensional contact maps inherently introduces latency. Here, we present mechanochromic tactile sensors that directly encode mechanical strain into spatially resolved structural colors, enabling vision-based tactile sensing with an unprecedented combination of high resolution, real-time operation, and intrinsic simplicity. The devices consist of a stretchable mechanochromic Bragg reflector embedded between two soft silicone layers, whose thickness can be tailored to precisely map contact pressure or strain. As an example, we present topological maps of a fingertip, a one-penny coin, and a leaf, with ∼100 micrometer resolution. In comparison to the most performing vision-based tactile sensors, this was achieved without requiring any deep learning-based data enhancement and without introducing any computational latency. The straightforward applicability of this mechanochromic strategy to enhance vision-based tactile sensing in a simple yet powerful way underscores its transformative potential for uses as diverse as robotic gripping and handling, tactile product inspection, and enhanced human-robot interaction.
GaN p-channel field-effect transistors (p-FETs) are critical for enabling complementary integration of power and logic, while offering high breakdown capability. However, achieving high on-current in GaN p-FETs remains a significant challenge, primarily due to the low hole concentration, poor mobility, and challenges in forming stable, low-resistance ohmic contacts. Here, we present a novel GaN p-FET architecture that exhibits unconventional electron conduction, which helps enhance both thermal response and current modulation. We conduct a comprehensive investigation of heavily Mg-doped p++-GaN layers, focusing on contact optimization for high-temperature operation. Structural and interfacial characterization confirms high crystal quality and a thermally robust Ni/Au contact stack stabilized by an interfacial NixOy layer. This strategic interfacial layer, combined with moderate-temperature annealing, promotes Mg activation and suppresses oxygen-related traps, resulting in a ~ 73% reduction in contact resistance. Temperature-dependent analysis further reveals non-monotonic Schottky barrier modulation driven by interface evolution. Integrated into the device, this contact strategy enables thermally enhanced operation, with a drastically increase in on-state current and threshold voltage shifting positively by ~ 69% with temperature. These findings highlight a model shift in GaN p-FET design, where interface study and transport-mode innovation enable high-performance, thermally resilient devices for next-generation power integration.
Long non-coding RNAs and N6-methyladenosine RNA methylation represent two pivotal layers of gene regulation. Their extensive crosstalk forms a sophisticated bidirectional network that is fundamentally rewired in cancer. This review synthesizes current knowledge to elucidate the principles and consequences of this synergistic axis. We detail how m6A modification dictates long non-coding RNA stability, splicing, localization, and function through recruitment of distinct "reader" proteins, with one "reader" family primarily mediating decay while another promotes stabilization. Conversely, we examine how long non-coding RNAs act as scaffolds, guides, and decoys to modulate the activity and specificity of the m6A machinery, establishing powerful feedforward and feedback loops. This reciprocal regulation converges on multiple cancer hallmarks, including proliferation, metabolic reprogramming, immune evasion, stemness, and therapeutic resistance. We critically discuss experimental strategies to establish causal relationships, including site-directed mutagenesis, CRISPR-based editing, and rescue assays. We also evaluate current methodological limitations in m6A detection, from antibody-dependent approaches to emerging nanopore sequencing, and highlight how single-cell and spatial transcriptomic technologies can resolve cell-state-specific networks within the tumor microenvironment. From a translational perspective, we compare small molecule inhibitors targeting m6A "writers" with RNA-based therapies, addressing their respective delivery challenges and toxicity concerns. Finally, we outline how m6A-related long non-coding RNA signatures serve as prognostic biomarkers and liquid biopsy tools for non-invasive cancer monitoring. By integrating molecular mechanisms with clinical perspectives, this review charts a roadmap for targeting the epitranscriptomic-long non-coding RNA circuit in precision oncology.
Depression is a common psychiatric disorder during pregnancy and the postnatal period. Consequently, antidepressant treatment is primordial for the safety of the mother and the neonate. Clomipramine (CMI) is a tricyclic antidepressant that has been prescribed even when the evidence suggests potential adverse effects on the neurodevelopment of the offspring, considering that antidepressant drugs can be transferred through breast milk. Nevertheless, in some cases, when the benefits outweigh the risks, it is used to treat severe depression in pregnant women. In rodents, postnatal administration of CMI causes persistent behavioral and neurophysiological alterations in adulthood. By contrast, a rewarding experience, such as mating, improves motivational and copulatory behavior in rodents through neuroplasticity in brain structures involved in reproduction. In a previous work, we reported that postnatal exposure to CMI disrupts the motivational and copulatory components of female sexual behavior during a single copulatory test. Therefore, the purpose of this study was to examine the effects of postnatal CMI treatment on female sexual behavior and reproductive tissues, and to determine whether sexual experience serves as a modulatory factor that ameliorates its potential impact on sexual performance. Female pups were divided in two groups, CMI group (30 mg/Kg) and the control group (NaCl 0.9%). Each group received a daily subcutaneous injection with CMI or saline solution from the 8th to 21st postnatal days. Behavioral test and histological analysis were performed at 3 months of age. The results indicated that postnatal CMI administration disrupts receptive but not proceptive behaviors. Repeated sexual encounters with males partially reversed the receptivity impairment in CMI-treated females, as it occurs in control rats. Histological data showed that CMI reduces the population of primordial and primary follicles; however, no morphological modifications were detected in the uterine layers. In conclusion, the data show that even when sexual experience partially improved copulatory behavior in female rats exposed to CMI during the postnatal period, ovarian development was affected, which could compromise fertility.
Microbial interactions form food webs and are crucial for regulating food web stability. A structurally stable food web is a prerequisite for aquatic ecosystem functioning. Dam construction and reservoir operation significantly alter environmental conditions, in which hydrodynamic, trophic, and vertical variations affect all trophic levels of the hierarchy via top-down and bottom-up forces, with profound effects on microbial food web structure and stability. However, little is known about which external environmental drivers primarily influence the shaping of microbial food web structure, and how phytoplankton-heterotrophic bacteria interactions affect the stability of the entire microbial food web in river-reservoir systems. Here we explored multi-trophic interactions among phytoplankton, heterotrophic bacteria, and protists along trophic, longitudinal (hydrodynamic), and vertical gradients in five reservoirs of the upper Yangtze River. Hydrodynamic conditions explained more variation in microbial food web stability than trophic and vertical conditions. Food web stability declined along trophic, longitudinal, and vertical gradients, accompanied by reductions in α-diversity, K-strategist bacteria abundance, and food web complexity, together with an increase in the proportion of positive phytoplankton-heterotrophic bacteria associations. Potential phytoplankton-heterotrophic bacteria mutualism was intensified by an increase in trophic state, a reduction in water flow velocity, and a shift from bottom to upper layers, which had an adverse effect on microbial food web stability by reducing predation pressure. Our findings highlight the importance of hydrodynamic variations in shaping microbial food web structure and underscore the pivotal role of phytoplankton-heterotrophic bacteria interactions in affecting food web structural stability, providing critical insights for river-reservoir system management.
Central Serous Chorioretinopathy(CSC) is a chorioretinal disorder, predominantly affects young to middle-aged adults, resulting serious vision disorder. This study aimed to develop a Bayesian network model to predict the key factors influencing the early therapeutic efficacy of 577 nm-SML in patients with CSC. A total of 159 patients (159 eyes) diagnosed with CSC and treated with 577 nm-SML at the First Affiliated Hospital of Guangxi Medical University from January 2019 to November 2023 were retrospectively analyzed. Baseline data including age, sex, eye side, disease course, and past medical history were collected. Ophthalmic imaging detects central macular thickness (CMT), macular foveal volume (MFV within 1mm, 3mm, 6mm diameter), height and area of subretinal fluid (SRF), structural changes in the outer retinal layers (ORL), type and area of leakage lesions, etc. Influential variables significantly associated with 577nm-SML efficacy were screened using LASSO regression, then construct a Bayesian network model to predict factors that significantly affect the therapeutic effect. LASSO regression identified 19 significant variables related to treatment outcomes from the 40 possible risk factors included, including disease duration, sex, eye Side, smoking, hormone, macular foveal volumes (3 mm and 6 mm diameters), and the height and area of SRF, ORL integrity, typical PED, location of PED, location of RPE bulging, heterogeneity of NPL, HF of ORL, HF of choroid, leakage type, leakage location, leakage correlate with OCT. The Bayesian network presents complex interactions among these factors, shows that patients with smaller macular foveal volumes (within 3 mm diameter), shorter disease duration, and focal leakage exhibited superior responses to 577nm-SML treatment. The therapeutic response to 577nm-SML in CSC is influenced by multifactorial dynamics. Bayesian network can well present the complex network relationship between the therapeutic effect of 577nm-SML and related influencing factors, and identify potential risk factors that affect early efficacy.
Depression in dementia with Lewy bodies (DLB) is a common neuropsychiatric symptom associated with reduced quality in life. Structural, functional and neurochemical abnormalities in glutamatergic and GABAergic neurotransmission are implicated in the pathophysiology of depression, showing changes in regions involved in emotional processing, including the subgenual cingulate cortex (sgACC), which shows pathological changes in DLB. Using post-mortem tissue from DLB patients and controls, we assessed synaptic and neurochemical changes within the sgACC in relation to depression in DLB. We identified a reduction of layer V GABAergic neurones in depressed DLB cases, potentially indicating reduced inhibition of layer V pyramidal neurons, leading to altered excitation. High-resolution confocal imaging demonstrated a significantly increased volume of presynaptic glutamatergic synapses containing phosphorylated α-synuclein (s129) in DLB cases, and specifically in depressed DLB cases, potentially as a compensatory response to the accumulation of pathological s129. GABAergic synapses containing s129 were enlarged in both DLB groups showing no depression specific changes. Selective reductions in glutamatergic and GABAergic receptors were seen in depressed DLB cases, suggesting a role in the pathophysiology of depression in DLB, that may prove amenable to therapy with fast-acting antidepressants. Interactions with serotonergic and dopaminergic innervation were observed, where preserved 5HT3B receptor and calbindin characterised non-depressed DLB patients. In depressed DLB cases, this may lead to reduced inhibition of lower layer pyramidal neurones due to reduced dopaminergic coupling and enhanced excitatory activity within the cingulate. Overall, our findings suggest altered excitatory and inhibitory neurotransmission may contribute to the development of depression in DLB.
The material heterogeneity and structural discontinuity of welded rail joints in high-speed railways make them vulnerable to fatigue damage under wheel-rail rolling contact. In this study, a three-dimensional finite element model of a 1380 MPa carbide-free bainitic rail welded joint was developed, and the fatigue damage behavior was assessed using the Findley critical-plane multiaxial fatigue criterion. The results show that the welded joint causes pronounced stress concentration, with the peak contact stress increasing from approximately 1000 MPa in the base metal to about 1120 MPa near the weld center. Fatigue damage is mainly concentrated in the weld zone and gradually decreases along the longitudinal direction toward both sides. The maximum fatigue damage occurs in the subsurface region approximately 2-3 mm beneath the rail surface. As the wheel load increases from 80 kN to 120 kN, the fatigue damage in the weld zone increases markedly. A clear coupling effect between wheel load and friction coefficient is also observed, indicating that higher wheel loads and friction coefficients accelerate fatigue damage accumulation. These findings identify the weld zone as the most fatigue-critical region under rolling contact loading and indicate that the subsurface layer at a depth of 2-3 mm is the preferential site for fatigue crack initiation. The results provide a useful reference for life assessment and maintenance management of welded rail joints in high-speed railways.
Realizing Chern insulators with Chern numbers >1 remains a major goal in quantum materials research. Such platforms promise multichannel dissipationless chiral transport and access to correlated phases beyond the conventional C = 1 paradigm. We discover high-Chern-number orbital magnets in twisted monolayer-multilayer rhombohedral graphene, denoted (1 + n) with n = 3, 4 and 5. Magnetotransport measurements show pronounced anomalous Hall effects at one and three electrons per moiré unit cell when they are polarized away from the moiré interface. Across these systems, we observe a clear topological hierarchy C = n, revealed by Středa trajectories and quantized Hall resistance, supported by self-consistent mean-field calculations. Moreover, we realize both electrical and magnetic switching of the high-Chern-number states by flipping the valley polarization. These results establish a tunable hierarchy of orbital Chern magnets in twisted rhombohedral graphene, offering systematic control of Chern number and topology through layer engineering in pristine graphene moiré systems.
Lignocellulosic biomass is the most abundant renewable carbon source; its efficient utilization helps reduce dependence on fossil raw materials and promotes sustainable economic and social development. However, the sugar platform technology based on enzymatic hydrolysis and conversion of lignocellulose still faces major challenges. Among them, the non-productive adsorption of cellulase by lignin seriously restricts the efficiency and economics of the enzymatic hydrolysis process. Studies have shown that the presence of lignin can reduce cellulase hydrolysis efficiency by 30 %-80 %, and enzyme loading must be increased by 2-5 fold to achieve the same saccharification yield, significantly raising production costs. How to overcome the recalcitrance of lignin to enzymatic hydrolysis is an important topic in the industrial utilization of lignocellulosic biomass. Non-productive adsorption mainly relies on short-range non-covalent interactions such as hydrophobic interactions, hydrogen bonding, and electrostatic interactions. These interactions directly promote the ineffective binding of enzymes to the lignin surface. Recent studies have further revealed that long-range Van der Waals forces, electric double-layer interactions, and long-range hydrophobic interactions play an important promoting role in the initial approach stage between enzymes and lignin. Together, they constitute a long-range capture - short-range locking multi-step adsorption model, further exacerbating the intensity and persistence of non-productive adsorption. This review systematically elucidates the types and mechanisms of lignin-cellulase non-covalent interactions, analyzes the impacts of lignin structural characteristics (unit composition, functional groups, molecular weight) and cellulase properties (domain functions, surface hydrophobicity/charge), and evaluates current mitigation strategies.
Strut defects are prone to occur in additively manufactured lattice structures and can significantly degrade their mechanical performance, while non-destructive testing of such periodically complex architectures remains challenging. This study proposes a laser ultrasonic inspection method based on zero-group-velocity (ZGV) Lamb wave features to detect strut defects in single-layer lattice structures. A numerical framework combining dispersion analysis, single-frequency response analysis, and transient spectral analysis is established to clarify the formation and evolution of ZGV modes in intact and defective structures. The results show that the intact lattice supports a distinct S0-ZGV mode, whereas a strut defect not only shifts the initial ZGV frequency but also induces a defect-related feature-guided-wave (FGW) branch and the corresponding FGW-ZGV mode. Intact and defective regions exhibit markedly different localized responses at the ZGV frequencies, which form the basis of the proposed detection method. By extracting the spectral energy near the ZGV frequencies, a defect index (DI) is constructed for point-by-point defect detection. Numerical results further show stable and distinguishable DI between defective and intact regions for different defect severities. Laser ultrasonic experiments on additively manufactured Ti-6Al-4V lattice specimens verify that defective and intact regions possess different local ZGV resonance frequencies, and that both reference-frequency strategies based on S0-ZGV and FGW-ZGV can achieve effective defect visualization. These results demonstrate that the proposed method provides an effective approach for non-contact defect detection in complex lattice structures.