Search Results (1,558)

The corrosion mechanism and corrosion behavior of a monolithic Zr-based (Zr₄₈Cu₃₆Al₈Ag₈)Si_0.75 bulk metallic glass (BMG) and a Zr-based (Zr₄₄Cu₃₆Al₈Ag₈Ta₄)Si_0.75 BMG matrix composite (BMGMC) in 3.5 wt.% NaCl solution were investigated. Potentiodynamic polarization tests were conducted to evaluate the corrosion and passive behavior of BMGs. Both monolithic BMG and BMGMC exhibited distinct pitting corrosion in sodium chloride solution. The monolithic BMG exhibited a higher value of pitting overpotential, η_pit, and a wider passive region, when compared to that of BMGMC, indicating that the monolithic BMG has a better pitting resistance than the BMGMC. The worse corrosion resistance of BMGMC can be attributed to the weak passive film of the interface area between the precipitates and the glassy matrix, where it can be more easily broken through by halide ions, Cl⁻, preferentially. Furthermore, galvanic corrosion can occur due to the potential difference between Ta precipitates and the matrix of BMGMC, leading to an even more severe corrosion of the BMGMC. Full article

The Internet of Vehicles (IoV) relies on frequent vehicle-to-roadside-unit (RSU) access over open wireless channels, making efficient authentication and key establishment essential. In many existing authentication and key agreement (AKA) schemes, a target RSU receives and processes a request before an invalid sender is rejected, which can waste roadside computation under dense invalid-request traffic. This paper presents EDAKA-IoV, an elliptic-curve-cryptography-based AKA scheme that separates admission filtering from end-to-end session-key establishment. A trusted authority (TA) performs Lightweight Polynomial-based Pre-Verification (LPPV) to discard invalid authentication requests before they reach the target RSU, while the vehicle and RSU establish the final session key. A current–pending dual-state mechanism prevents permanent de-synchronization during dynamic pseudo-identity renewal without adding another communication round. Formal analysis under an eCK-style model, ProVerif verification, and heuristic analysis evaluate session-key secrecy, injective mutual authentication, privacy, and resistance to the considered attacks. Optional offline precomputation moves two fixed-base scalar multiplications outside the online phase and reduces the non-polynomial online computation component by approximately 48.8%. With fixed-length compressed point encoding, the authentication exchange requires 2336 bits. The workload analysis shows that the RSU-side processing reduction is proportional to the invalid-request ratio, while the TA still performs record lookup, hashing, and degree-dependent polynomial evaluation for every received request. EDAKA-IoV therefore provides a balanced authentication solution for resource-sensitive IoV deployments. Full article

Tropane alkaloids (TA) constitute a class of plant specialized metabolites with important pharmaceutical applications, including the anticholinergic agents hyoscyamine and scopolamine and the local anesthetic cocaine. Over the past decade, advances in genomics, structural biology, and synthetic biology have substantially revised our understanding of TA biosynthesis, leading to the identification of numerous key biosynthetic enzymes and evolutionary mechanisms. This review comprehensively summarizes current knowledge of TA biosynthesis from precursor formation to structurally diverse end products. We describe the pathway from putrescine to tropinone, the stereoselective metabolic branching mediated by Tropinone Reductases, and the downstream biosynthesis of medicinal tropane alkaloids, calystegines, and cocaine. Particular emphasis is placed on recent discoveries concerning catalytic mechanisms, structural determinants of substrate specificity, metabolic compartmentalization, and the convergent evolution of TA biosynthesis in Solanaceae and Erythroxylaceae. We further integrate advances in genomics, evolutionary biology, and metabolic engineering to highlight emerging strategies for microbial production and pathway redesign. By providing a comprehensive synthesis of recent progress and critical perspectives on unresolved questions, this review offers an updated framework for understanding TA biosynthesis and supports future research in plant specialized metabolism, synthetic biology, and natural product engineering. Full article

A hard protein corona was engineered onto tannic acid-modified magnetic nanoparticles (SAMN@TA), a magnetic and luminescent core–shell nano-carrier, using Bovine Serum Amine Oxidase (BSAO), an enzyme catalyzing the oxidation of polyamines and producing the corresponding aldehydes and hydrogen peroxide. The absorption and intracellular bioactivity of the self-assembled multimodal SAMN@TA@BSAO were investigated on an intestinal barrier model built with human colorectal adenocarcinoma (Caco-2) cells. The tailored BSAO corona possessed fouling resistance and, at the same time, was able to activate the clathrin-mediated endocytosis (CME) mechanism. Despite its size and intrinsic complexity, the nano-vehicle was effectively transported across the cell layer, safely transiting across the cell cytoplasm and reaching the lumen. As a function of intracellular polyamine concentration, the system’s biological activity induced intracellular oxidative stress, leading to the activation of the Keap1/Nrf2 oxidative protection pathway. The SAMN@TA@BSAO effect was well described by a dose–response curve with an EC50 of around 30 µg mL⁻¹ and a programmable killing efficiency (>50.0%), recalling the feasibility of a low molecular weight drug administration. The present study contributes to the nascent knowledge on engineering protein corona as a key to rationally design nanomaterials for biomedical applications. Full article

To address the need for effective biocontrol of poplar anthracnose caused by Colletotrichum gloeosporioides, in this study, 20 Trichoderma strains were isolated from the rhizosphere of seven tree species on Tianzhu Mountain to screen for potent growth-promoting and antifungal agents. The inhibitory effects of the strains on C. gloeosporioides (Cgl) were evaluated through mycelial growth assays, volatile organic compound tests, and fermentation filtrate analysis, while their growth-promoting capabilities and induction of systemic resistance were assessed in poplar seedlings via biomass measurement, stomatal analysis, and gene expression profiling. The results demonstrated that T. asperelloides Tas369 significantly inhibited pathogen growth and improved seedling growth, increasing stomatal density by 134% and inducing phenylalanine ammonia-lyase (PAL) and peroxidase (POD) enzyme activities. Notably, Trichoderma composite (Tcom) outperformed single-strain treatments, achieving 89.8% control efficacy, reducing the malondialdehyde content by 1.1 mmol/g, and significantly upregulating the key defense genes NPR1 (14.32-fold) and PR1-1 (219.79-fold) through increased activity of the salicylic and jasmonic acid signalling pathways. In conclusion, while Tas369 exhibits strong individual potential, the Tcom consortium provides superior biocontrol through multiple mechanistic interactions, offering an effective and sustainable approach for managing poplar anthracnose in forestry applications. Full article

Tilia americana var. mexicana is a medicinal species whose reported pharmacological effects primarily target the central nervous system, including anxiolytic, antidepressant, and anticonvulsant activities, attributed in part to flavonoids such as tiliroside (8). In this study, 14 compounds were isolated and identified from the methanolic extract (Ta-MeOH) and evaluated by molecular docking against the monoamine oxidases MAO-A and MAO-B, enzymes implicated in Parkinson’s disease (PD) due to their involvement in dopamine metabolism. Chemical analysis identified six terpenes: α- and β-amyrine (1–2), β-sitosterol (3), stigmasterol (4), ursolic acid (5), and β-sitosterol glucoside (6); the novel diglycosylated monoterpene 4α-terpineol sambubioside (7), characterized through its hexaacetate derivative (7a); the flavonoids tiliroside (8) and rutin (9); sucrose (10); and four phenolic compounds: scopoletin (11), caffeic acid (12), coumaric acid (13), and chlorogenic acid (14). Molecular docking against monoamine oxidases A and B (MAO-A and MAO-B) was used as a computational strategy to prioritize isolated metabolites for biological evaluation. β-Sitosterol glucoside (6), 4α-terpineol sambubioside (7), tiliroside (8) and rutin (9) exhibited the most favorable docking scores toward MAO-B, with predicted binding energies of −10.8733, −11.1434, −12.16986 and −12.9474 kcal/mol, respectively. Considering the docking results together with phytochemical and experimental criteria, (6) and (8) (1 mg/kg) were prioritized for biological evaluation, together with Ta-MeOH extract (100 mg/kg) and selected fractions (25 mg/kg), in a reserpine-induced mouse model of parkinsonism using L-DOPA (150 mg/kg) as a positive control. In the open field test, spontaneous locomotor activity was assessed by total crossings and expressed as AUC. Ta-MeOH significantly increased locomotor activity compared with the reserpine-treated group (AUC: 1281.8 vs. 551.7, respectively; p < 0.05). Tiliroside (8) also increased locomotor activity (AUC: 858). In the Rota-Rod test, fine motor coordination was assessed by latency to fall and expressed as AUC. Ta-MeOH showed the greatest recovery, with AUC values of 431, 89, and 34 at 4, 10, and 20 rpm, respectively. In addition, treatments derived from T. americana attenuated behavioral alterations induced by reserpine in the Irwin test. Overall, this study demonstrates that integrating phytochemical isolation, molecular docking, and in vivo pharmacological evaluation provides a useful strategy for prioritizing bioactive metabolites from T. americana. These findings support further pharmacological investigation of this medicinal species and its isolated metabolites, while additional studies are required to establish their molecular targets and mechanisms of action. Full article

Sprint performance improves throughout adolescence as a result of both structural and neuromuscular development. In particular, increases in body height, lower limb length, and muscle volume have been consistently linked to improvements in sprint performance. However, allometric scaling of force, speed, and power remain lower in adolescents compared to adults even after structural differences are accounted for, implicating neural factors as independent contributors to performance development. The purpose of this study was to investigate differences in neuromuscular activation patterns of the lower limb muscles during maximal sprinting between youth male athletes across two age groups (U19: 17–19 years; U16: 13–16 years). Eighteen athletes performed a 50 m maximal sprint. Spatiotemporal variables (running speed, step frequency, step length) were measured over 30–50 m using a high-speed camera (240 Hz) and timing gates. Electromyographic (EMG) signals were recorded simultaneously from ten lower limb muscles using wireless EMG sensors (2000 Hz): rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), gluteus maximus (Gmax), gluteus medius (Gmed), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), gastrocnemius (GAS), and soleus (SOL). Root mean square (RMS) amplitude was calculated across four gait phases (contact, early-swing, mid-swing, late-swing) and normalised to maximal voluntary Isometric contraction (%MVIC). The U19 group demonstrated significantly greater running speed (U19: 9.49 ± 0.39 vs. U16: 8.67 ± 0.25 m·s⁻¹, p < 0.001), step frequency (U19: 4.49 ± 0.12 vs. U16: 4.35 ± 0.16 Hz, p = 0.004), and step length (U19: 2.12 ± 0.12 vs. U16: 1.99 ± 0.06 m, p = 0.010) than U16. The overall pattern of lower limb muscle activation across the gait cycle was broadly similar between groups; however, a significant group × phase interaction was observed for RF (p = 0.003, F = 5.257, η² = 0.247), with post hoc analysis revealing greater RF activation during early swing in U19 (p = 0.033). These findings may indicate that sprint-specific training in youth athletes is associated with not only structural but also neuromuscular differences, specifically reflecting enhanced RF recruitment during the phase-critical moment of early swing—a window in which high-threshold motor unit activation is most mechanically decisive. EMG-based assessment of hip flexor activation during maximal sprinting may provide a complementary tool, pending further validation, for talent identification and training prescription in youth track and field. Full article

Composition criteria for refractory high-entropy alloys (RHEAs) reliably predict whether a candidate composition forms a single-phase body-centred-cubic (BCC) solid solution, but not which BCC-confirmed composition will be strongest. Here we revisit seven previously reported RHEA compositions on freshly arc-melted material of our own, confirm each as single-phase BCC using full-spectrum X-ray diffraction re-indexing, and screen ten descriptors obtainable before mechanical testing against their room-temperature compressive yield strength: five compositional (mean atomic radius r⁻, mixing enthalpy ΔH_mix, atomic-size mismatch δ, VEC, and melting point T_m), two lattice-scale (Nelson–Riley parameter a₀ and Williamson–Hall apparent microstrain ε) and three microstructural (KAM, ELM₁₅, and grain ECD). Only ΔH_mix ranks the strengths, and its direction inverts the usual expectation: the less negative the mixing enthalpy, the stronger the alloy. Refractoriness carries no ranking information, and the most refractory member, NbMoTaW, is second weakest of six. At n = 6 only a perfect ranking reaches a Benjamini–Hochberg q below 0.05 across ten descriptors, so the q of 0.167 obtained here measures cohort resolution: a ranking of this magnitude clears the corrected threshold from eight alloys upwards. Mean atomic radius separately predicts a₀ across all seven alloys. Full article

Background: Advanced varus ankle osteoarthritis is challenging because correction of malalignment must be balanced against preservation of the native ankle joint. This study evaluated the clinical and radiographic outcomes of distal tibial oblique osteotomy (DTOO) with structural strut allografting, which permits individualized correction and provides mechanical support to the osteotomy gap. Methods: This retrospective case series included 20 patients and 20 operated ankles with Takakura stage IIIa (n = 13) or IIIb (n = 7) varus ankle osteoarthritis who underwent DTOO with structural strut allografting between 2012 and 2024. Clinical outcomes included Manchester–Oxford Foot Questionnaire (MOXFQ), American Orthopaedic Foot & Ankle Society (AOFAS), 12-Item Short-Form Survey (SF-12), and Visual Analog Scale (VAS) pain scores. Radiographic parameters included tibial articular surface angle (TAS), tibial lateral surface angle (TLS), medial malleolar angle (MMA), talar tilt angle (TTA), and tibiotalar surface angle (TTS). Results: Significant improvements were observed at final follow-up. MOXFQ scores decreased from 57.66 ± 22.01 to 10.63 ± 9.72 (p < 0.001), AOFAS scores increased from 63.75 ± 15.17 to 85.45 ± 8.37 (p < 0.001), and VAS pain scores decreased from 4.30 ± 1.75 to 1.00 ± 1.30 (p < 0.001). The SF-12 PCS increased from 45.23 ± 8.48 to 47.96 ± 7.93 (p = 0.258), and the MCS increased from 53.51 ± 9.85 to 55.60 ± 4.75 (p = 0.377); neither change was statistically significant. Significant correction was achieved in TAS (p < 0.001), TLS (p < 0.001), MMA (p = 0.019), and TTS (p < 0.001), with no significant change in TTA (p = 0.336). All achieved radiographic union within 3 months postoperatively. Conclusions: DTOO with strut bone allografting enables alignment correction in advanced varus ankle osteoarthritis, including Takakura stage III, while preserving the ankle joint. This technique is an effective joint-preserving option for severe deformities. Full article

Refractory high-entropy and compositionally complex alloys are routinely compared by nominal composition and as-processed phase, yet processing changes the material that is actually tested. This is a critical, mechanism-led narrative review rather than a systematic review; the databases, complete search strings, screening sequence, inclusion and exclusion criteria, and evidence-grading rubric are reported so that coverage and selection bias can be assessed independently. This review synthesizes 186 publications around the NbTaV compositional core and compares alloys through directly measurable features of the processed state: interstitial content, local chemical order, grain-boundary chemistry, defect and grain architecture, phase morphology, compositional gradients and surfaces. Every source is assigned to a compositional tier and graded along four evidence axes: 96 of the 186 sources report Nb–Ta–V-containing states (Tier I), 58 are body-centered cubic refractory comparators (Tier II) and 32 are transferred-mechanism analogues (Tier III), and only 14 Tier I sources supply direct tensile, fracture or tensile-creep measurements. This asymmetry, rather than any disagreement between compositions, is the field’s binding evidence constraint. Direct tensile, fracture, and creep measurements are kept separate from compression, hardness, calculation, and screening evidence. This separation reconciles observations that otherwise appear to conflict: oxygen can strengthen or embrittle; lattice distortion can raise strength while lowering dislocation mobility; local order can harden the alloy, redirect defects or precede decomposition; and second phases help only within morphology- and service-specific compatibility windows. The strongest tensile behavior is obtained when mobile plasticity carriers are preserved, and interstitials, interfaces and phase continuity are simultaneously controlled. High-temperature, environmental, and irradiation performance depend additionally on the transition from the as-manufactured condition to the state that evolves during service. Quantitative matching tolerances for the convergent-state falsification test, service-condition-specific validation hierarchies, ordinal scoring rules for the phase-compatibility map, and a source-level audit of every quantitatively compared value are provided so that the framework can be tested and the synthesis independently checked. Full article

Residual stresses generated during laser powder bed fusion (LPBF) can cause substantial distortion in slender structures, compromising dimensional accuracy and structural reliability. This study tests the hypothesis that, under identical nominal processing conditions, geometry-dependent stiffness and constraint govern how the evolving thermally induced stress field is redistributed and manifested as warpage after support removal. Bridge-type TA15 titanium alloy cantilever specimens with different spans, thicknesses, and support densities were fabricated by LPBF, and their post-cut warpage was quantified by three-dimensional scanning. A coupled thermo-mechanical finite element model was validated against the measured deformation profiles and subsequently used to examine simulated stress evolution during deposition and redistribution after support removal. Cantilevers with different spans approached similarly high simulated surface tensile-stress plateaus in the constrained as-built state but exhibited markedly different measured warpage after cutting, showing that the as-built stress magnitude alone does not reliably rank post-release deformation. Increasing span reduced global flexural resistance and enlarged the effective bending arm, whereas increasing thickness enhanced flexural rigidity and suppressed curvature even when relatively high localized stress was retained. With the total support volume held constant, changing support density altered the system-level constraint through the combined effects of support-leg stiffness, support spacing, local thermal and mechanical response, and deformation compatibility. Together, these results provide an experimentally supported process-structure interpretation of LPBF cantilever distortion across controlled variations in span, thickness, and support distribution. Full article

Bitterness of oral active pharmaceutical ingredients (APIs) remains a major barrier to patient adherence, particularly in pediatric and geriatric populations. Conventional taste-masking strategies primarily rely on formulation-based approaches, but do not always sufficiently suppress activation of bitter taste pathways. Increasing attention has focused on taste-modulating compounds, including umami substances, which reduce bitterness through multiple stages of taste processing, including peripheral receptor responses, perceptual taste interactions, and central sensory integration. This review provides an integrated overview of umami-mediated bitterness suppression from molecular, sensory, neural, and analytical perspectives. Interactions between TAS2R bitter receptors and T1R1/T1R3 umami receptors, including possible downstream signaling convergence and sensory integration mechanisms, are discussed in relation to bitterness suppression. Representative umami compounds, including monosodium glutamate (MSG) and umami peptides, have been reported to suppress the bitterness of several bitter APIs, suggesting potential applicability beyond compound-specific taste-masking strategies. Recent advances in electronic taste-sensing technologies, particularly lipid/polymer membrane-based systems, enable quantitative evaluation of bitterness modulation. Because taste sensors primarily reflect peripheral physicochemical interactions rather than central sensory processing, this review further discusses the potential utility of the bitterness sensor BT0 for evaluating the peripheral component of bitterness suppression, drawing primarily on studies using MSG and representative umami peptides. Collectively, current evidence suggests that umami-mediated taste modulation may provide a rational framework for improving oral pharmaceutical palatability. Full article

In this study, the influence of precipitated Laves particles on the metastable pitting of VCrFeTa_0.1W_0.1 and VCrFeTa_0.2W_0.2 refractory high-entropy alloys (HEAs) in 3.5 wt.% NaCl solution was investigated. Microstructures and corrosion behaviors were characterized by XRD, SEM, TEM, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS), and the underlying mechanisms were elucidated. The PDP test results demonstrate that the precipitated Laves particles reduce the pitting resistance of HEAs. The corrosion current densities of VCrFeTa_0.1W_0.1 and VCrFeTa_0.2W_0.2 HEAs are 0.066 and 1.361 μA/cm², respectively, and the pitting potentials are 1.058 and 0.881 V, respectively; that is, reducing the Laves-particle content lowers the corrosion current density by a factor of approximately 20 and raises the pitting potential by approximately 180 mV. The corrosion current density and pitting potential of VCrFeTa_0.1W_0.1 are competitive with those of reported HEAs and traditional alloys. Full article

A multicomponent Ni₅₄Cr₂₈Mo₈Nb₅Ta₅ nickel-based superalloy was produced by vacuum induction melting followed by homogenization, hot forging, solution treatment, and aging to investigate its microstructural and mechanical behavior. The X Ray Fluorescence (XRF) analysis confirmed excellent agreement between the nominal and experimental chemical compositions. The X Ray Diffraction(XRD) combined with Rietveld refinement revealed a microstructure dominated by three closely related to face-centered cubic (FCC) (A1) solid-solution regions with slightly different lattice parameters, indicating local compositional variations. The Scanning Electron Microscopy(SEM)/Energy Dispersive Spectroscopy (EDS) observations showed a generally homogeneous elemental distribution, while optical and electron microscopy identified a dendritic microstructure with elongated interdendritic constituents enriched in refractory elements. Mechanical characterization yielded an average hardness of 497 HV_0.5, a compressive strength of approximately 1950 MPa, and room-temperature yield and ultimate tensile strengths of 1050 MPa and 1320 MPa, respectively. Tensile strength gradually decreased with increasing temperature up to 900 °C, while ductility increased from 16% to 25% total elongation. The results indicate that the alloy develops a stable FCC matrix primarily strengthened by solid-solution hardening, with the measured mechanical performance suggesting an additional contribution from precipitation hardening. This study provides an experimental baseline for the development and optimization of conventionally processed Ni–Cr–Mo–Nb–Ta superalloys for high-temperature applications. Full article