This study presents a comprehensive numerical investigation into the laser-directed energy deposition (LDED) of homogeneous martensitic stainless steel coatings, with a particular focus on the role of the overlap ratio in governing melt pool dynamics and track morphology. A three-dimensional transient thermal-fluid coupled model was developed using the Fluent platform, incorporating the volume of fluid (VOF) method to accurately track the free-surface evolution, while integrally accounting for the coupled mechanisms of heat transfer, phase change, fluid flow and free-surface deformation. The model was employed to simulate the track geometry, transient temperature fields and flow field distributions under three representative overlap ratios of 30%, 40% and 50%. The results demonstrate that the optimal overlap ratio for achieving the best surface planarity of the martensitic stainless steel coating is 40%, which yields the highest flatness coefficient of 0.91, whereas ratios of 30% and 50% result in inferior surface quality characterized by groove formation (flatness 0.87) and localized protrusions, respectively. Increasing the overlap ratio from 30% to 50% markedly intensifies the inter-track thermal accumulation, with the thermal accumulation coefficient rising from 0.43% to 9.5%, accompanied by substantial enlargement of the melt pool dimensions and enhanced recoil pressure at the pool center. This validated three-dimensional thermal-fluid coupled model reliably captures the intricate interplay between overlap ratio, thermal behavior and track morphology, thereby providing a quantitative theoretical basis for optimizing LDED process parameters to improve the coating quality and service performance of laser-repaired hydraulic turbine blades.
Background: Decursin (Dec) has been identified as a potential component for treating allergic rhinitis (AR), but poor water solubility limits its application. This investigation was intended to develop a novel drug delivery system to optimize the therapeutic effects of Dec. Methods: Dec@PLLA-CCL17 was prepared and its drug delivery performance was assessed. Tregs were treated with PLLA, PLLA-CCL17, Dec, Dec@PLLA, or Dec@PLLA-CCL17. Cell viability was detected by CCK-8 assay, and the association between microspheres and Tregs was visualized by laser confocal microscopy. IL-4, IL-10 and TGF-[Formula: see text] levels in Tregs were measured using ELISA. Ovalbumin-induced AR mice were administered with Dec@PLLA or Dec@PLLA-CCL17, and nasal scoring was conducted. Pathological changes of the nasal mucosa were evaluated through hematoxylin and eosin (HE) staining. Treg numbers were assessed using flow cytometry, and histamine, IL-4, IL-10 and TGF-[Formula: see text] levels were detected using ELISA. Apoptosis was assessed by TUNEL staining and Western blot. Results: Dec@PLLA-CCL17 showed favorable drug delivery properties. PLLA and PLLA-CCL17 had no effect on the viability of Tregs. Furthermore, Tregs exhibited a stronger association with Dec@PLLA-CCL17 than with Dec@PLLA. Dec, Dec@PLLA and Dec@PLLA-CCL17 all remarkably increased cell viability and IL-10 and TGF-[Formula: see text] levels, while reducing IL-4 levels in Tregs, with Dec@PLLA-CCL17 having the strongest effect. In AR mice, both Dec@PLLA and Dec@PLLA-CCL17 notably reduced nasal symptom scores, alleviated nasal mucosal damage, increased Treg numbers, elevated IL-10 and TGF-[Formula: see text] levels, decreased histamine and IL-4 levels, and reduced apoptosis, with Dec@PLLA-CCL17 showing superior effects. Conclusion: Dec@PLLA-CCL17 alleviates AR by enhancing the proliferation and immunosuppressive function of Tregs.
Background: Cholangiocarcinoma (CCA) is an aggressive malignancy with poor prognosis, underscoring the need for novel diagnostic and therapeutic strategies. MicroRNAs (miRNAs) hold therapeutic promise but face delivery challenges. This study aimed to develop Folic Acid (FA)-targeted superparamagnetic albumin nanoparticles for miRNA delivery (FA-SAN-miRNA) and evaluate their potential for theranostic applications in CCA. Method: FA-SAN-miRNA was synthesized and characterized for size, zeta potential, morphology, magnetic properties, encapsulation efficiency and drug release. In vitro studies assessed cytotoxicity, cellular uptake, proliferation inhibition in CCA cells (RBE, HuCCT1) and MRI contrast efficacy. In vivo targeting and tracking capabilities were evaluated in a CCA xenograft mouse model. Results: The synthesized FA-SAN-miRNA nanoparticles were spherical, well-dispersed, and superparamagnetic, with a size of [Formula: see text][Formula: see text]nm and a zeta potential of [Formula: see text][Formula: see text]mV. They exhibited high miRNA encapsulation efficiency ([Formula: see text]) and a pH-responsive sustained release profile. FA-SAN-miRNA demonstrated low cytotoxicity, enhanced cellular uptake and significant inhibition of CCA cell proliferation compared to nontargeted controls. The nanoparticles served as effective T2 contrast agents for MRI. In vivo, FA-SAN-miRNA identified tumor cells with capture efficiency correlating with tumor burden. Conclusion: The FA-SAN-miRNA platform successfully integrates targeted miRNA delivery, pH-responsive release and MRI capability, demonstrating potential for identifying tumor cells and targeted delivery in CCA. This multifunctional nanoplatform offers a promising strategy for improving CCA management.
Rapid estimation of fatigue strength is important for the preliminary durability assessment of critical load-bearing components. The widespread use of conventional fatigue testing is nevertheless limited by its high cost and low efficiency, making it poorly suited to rapid material screening and engineering-oriented evaluation. Here, 304 stainless steel (SS 304) was adopted as a model material, and different rolling reductions were applied to produce distinct microstructural states and corresponding strength levels. On this basis, tensile and high-cycle fatigue tests were conducted to systematically examine the relationships among microstructural evolution, true stress–Vstrain behavior, and fatigue strength. As the rolling reduction increased, the material showed pronounced grain refinement accompanied by enhanced work hardening. Accordingly, the true ultimate tensile strength, true yield strength, and fatigue strength increased, whereas the post-yield hardening reserve progressively decreased. To account for these trends, a constrained semi-empirical fatiguestrength model was formulated using the true ultimate tensile strength, true yield strength, and postyield hardening reserve. The strength–Vhardening coupling imposes β=–α, leaving three independently calibrated coefficients whose values are material-family dependent. Predictive performance was assessed by leave-one-state-out cross-validation for material families containing at least four reported states. Compared with conventional strength-only correlations, the formulation incorporates descriptors of the true deformation response while retaining a compact form for engineering assessment.
High-entropy sulfides (HESs) have emerged as promising electrocatalysts for the oxygen evolution reaction (OER) due to their unique compositional tunability and synergistic effects. In this work, we report the rational synthesis of (FeCoNiCuMn)S HES nanorods via a facile hydrothermal process followed by a subsequent sulfidation treatment. For comparison, (FeCoNiCu)S and (FeCoNi)S medium-entropy sulfide (MES) nanorods were also prepared under identical conditions. The morphology, crystal structure and elemental valence states of the as-prepared samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Benefiting from the high-entropy effect, the (FeCoNiCuMn)S HES nanorods exhibit enhanced OER performance compared to their MES counterparts. It requires an overpotential of 295[Formula: see text]mV to achieve a current density of 10[Formula: see text]mA/cm 2 with a small Tafel slope of 54[Formula: see text]mV/dec, and demonstrates excellent long-term stability. The OER characterization results highlight the positive role of the multicomponent high-entropy design in boosting electrocatalytic performance. This work provides a rational strategy for developing efficient and stable HES nanorods for water oxidation.
Carbon dots (CDs) derived from citric acid (CA) as the primary carbon source have garnered significant attention in various research fields in recent years, attributed to their remarkable biocompatibility, negligible toxicity, low cost, environmental friendliness, abundant functional groups, high stability and excellent tunable photoluminescence (PL) characteristics. In this review, we systematically summarize the synthesis methods of CDs using CA as the primary carbon source and provide a detailed elaboration of their optical properties, encompassing ultraviolet–visible (UV–Vis) absorption, fluorescence (FL), delayed fluorescence (DF) and room-temperature phosphorescence (RTP). Furthermore, we introduce the diverse optical applications of this category of CDs, such as sensing, information encryption, light-emitting diodes (LEDs), bioimaging, and anti-tumor therapy. Ultimately, we discuss the challenges encountered by CDs derived from CA as the primary carbon source, future research directions and the development prospects of this field.
Ni-based catalysts are among the most promising candidates for oxygen evolution reaction (OER) in water electrolysis. However, their catalytic activity and long-term stability at high current densities still require further improvement. The development of multiphase, polycrystalline Ni-based catalysts is expected to leverage synergistic interactions among different elements to enhance electrocatalytic water-splitting performance. Herein, we report the hydrothermal synthesis of self-supported multiphase Ni(OH)(2)-based nanosheet arrays, which facilitate efficient electron transport and expose abundant active sites. The resulting electrode delivers a low overpotential of 298mV at a current density of 100mAcm(-2 )and maintains stable OER performance for over 25h. This work provides a feasible strategy for designing and developing multiphase electrocatalysts for high current density applications.
Photocatalysis is an eco-friendly technology to remove tetracycline hydrochloride (TCH) and can completely mineralize it to CO 2 and H 2 O under light irradiation. Bi[Formula: see text]O[Formula: see text]Cl 2 is a typical photocatalyst, but the high recombination of electrons and holes restricts the photocatalytic performance of bare Bi[Formula: see text]O[Formula: see text]Cl 2 . Herein, we design and in situ synthesize a 2D/2D Bi[Formula: see text]O[Formula: see text]Cl 2 /Ti 3 C 2 heterojunction using a solvothermal method. The Bi[Formula: see text]O[Formula: see text]Cl 2 /Ti 3 C 2 heterojunction exhibits enhanced photodegradation performance for TCH under visible light irradiation. The mechanism study indicated that the improved light absorption capacity, efficient electron–hole separation and transport capability and superoxide free radicals with strong oxidation capacity facilitate photocatalytic degradation of TCH. Moreover, the TCH’s possible degradation routes were put forward based on intermediates detected by LC–MS. This work proposes a new tactic for constructing Bi[Formula: see text]O[Formula: see text]Cl 2 heterojunction to promote its photocatalytic performance.
Focused on the synthesize of an immobilized tyrosinase (TYR) with high loading, fast response, high activity, easy recovery, simple preparation, as well as environmental protection, this work designed the structure of the novel carrier as follows: Firstly, Fe 3 O 4 nanoparticles was prepared by the reverse microemulsion technology, and then it was coated with polydopamine (DA) to endow it with excellent biocompatibility while avoiding the oxidation of Fe 3 O 4 . Secondly, glutaraldehyde (GA) was graft on the coating layer by Schiff base reaction to obtain Fe 3 O 4 @PDA-GA MNPs. Finally, based on the Schiff base reaction with the unreacted aldehyde group of glutaraldehyde, Tyrosinase was immobilized on the carrier by covalent bonding to obtain immobilized sample, Fe 3 O 4 @PDA-GA-TYR MNPs. Condition investigation found that the best performance of immobilized TYR was achieved at an enzyme solution concentration of 3.00 mg/mL, pH of 7.0, immobilization time of 20 hours, and a temperature of 35 °C. Under the optimal condition, enzyme activity (EA), enzyme loading capacity (ELC), and enzyme activity retention ratio (EAR) reached 16046 U/g, 56 mg/g, and 80.4%, respectively. Compared with free TYR, the reusability, operational reliability, and stable in storage immobilized TYR were evaluated, results showed that the im-mobilized TYR improve above properties at a large degree.
To address the need for efficient and readily separable adsorbents in protein purification, this study developed a novel amino-functionalized silica-coated hollow glass microsphere composite (HGM@SiO 2 -NH 2 ) using commercially available hollow glass microspheres (HGM) as the substrate. This material integrates the buoyancy of HGM with a functional silica-amine shell designed for electrostatic protein capture. Characterization via scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR) and acid–base titration confirmed the successful layered construction of the material, revealing a surface amino group density of 15.99[Formula: see text]mmol/g along with excellent dispersion and buoyancy-driven separation characteristics in aqueous media. Adsorption experiments using bovine serum albumin (BSA) as a model protein demonstrated a high adsorption capacity of 43.7[Formula: see text]mg/g. The adsorption process was rapid, reaching approximately 38[Formula: see text]mg/g (about 86% of the equilibrium capacity) within 30[Formula: see text]min, and was primarily governed by electrostatic interactions, as evidenced by optimal performance at pH 6.5. Kinetic studies showed strong adherence to the pseudo-second-order kinetic model, while equilibrium data fitted well with the Langmuir isotherm model, indicating monolayer adsorption onto homogeneous sites. Furthermore, efficient desorption (84.5%) was achieved within 30[Formula: see text]min using a high-concentration salt solution. The material also exhibited good stability over multiple cycles, retaining approximately 70% of its initial adsorption capacity after six consecutive adsorption–desorption cycles. This work demonstrates that HGM@SiO 2 -NH 2 is a promising and reusable adsorbent platform that combines efficient protein binding via electrostatic interactions with convenient buoyancy-assisted separation. These findings lay a solid foundation for its potential application in bioseparation processes.
Implant-associated infections and insufficient osseointegration remain major challenges that limit long term clinical performance of orthopedic implants. In recent years, near-infrared (NIR) light-triggered photothermal and photodynamic strategies have attracted increasing attention as efficient and controllable antibacterial approaches. In this work, a Mn-doped TiO 2 coating was fabricated on a Ti substrate via micro arc oxidation, followed by surface assembly of Ti 3 C 2 nanosheets using polydopamine as an interfacial mediator, thereby constructing a multifunctional MT@Ti 3 C 2 composite coating with combined antibacterial and osteogenic potential. The resulting coating exhibits enhanced hydrophilicity, improved corrosion resistance and stable interfacial adhesion, providing a favorable surface environment for biological interactions. The incorporation of Ti 3 C 2 nanosheets endows the coating with pronounced NIR responsiveness. Under 808-nm NIR irradiation, the MT@Ti 3 C 2 coating exhibits a pronounced photothermal response and significantly enhanced reactive oxygen species generation, including singlet oxygen and hydroxyl radicals, compared with the MT coating, which synergistically contributes to strong antibacterial activities with efficiencies of 98.4% against Escherichia coli and 96.8% against Staphylococcus aureus. In vitro simulated body fluid tests demonstrate that the coating effectively induces the formation of bone-like hydroxyapatite, indicating enhanced bioactivity. Further in vitro cell studies reveal good cytocompatibility of the MT@Ti 3 C 2 coating, along with promoted early cell adhesion and enhanced cell proliferation, highlighting its potential for multifunctional surface modification of orthopedic implants.
The frequent outbreaks of viral diseases in recent years have posed significant threats to the sustainable development of animal husbandry, resulting in substantial economic losses. The escalating complexity of multi-virus coinfections in swine populations necessitates the development of advanced multiplex detection platforms. Therefore, this research presents a novel dual-mode magnetoelastic (ME) sensing platform with multiple reaction chambers for parallel multi-virus detection. The dual-mode signal output based on frequency signals and visual colorimetric signals can improve detection accuracy and reliability through complementary cross-verification while also mitigating the limitations associated with single-mode approaches. Based on the magnetoelastic property of the Metglas 2826 chip, that is, load mass changes lead to resonance frequency shift (RFS), the virus concentration can be quantified by RFS. The sandwich immunoassay structure of antibody/virus/enzyme-labeled antibody was applied to amplify the signal and, based on the mechanism of enzyme-catalyzed to produce colored substance, enabled visual colorimetric readout. The ME biosensor consisted of a printed circuit board (PCB)-embedded planar coil array and a PDMS membrane with microchannels and multiple reaction chambers embedded with the Metglas 2826 chip, enabling parallel multi-virus detection in one drop and significantly improving the detection efficiency. The ME biosensor achieves a broad detection range (100[Formula: see text]pg/mL–1[Formula: see text][Formula: see text]g/mL) for the detection of African Swine Fever Virus (ASFV) P72, Porcine Parvovirus (PPV) VP2, and Porcine Circovirus (PCV) CAP2, with the detection limit of 100 pg/mL. This integrated ME sensing platform provides a low-cost, high-sensitivity, portable method adaptable to complex environments for the parallel multi-virus detection, demonstrating significant potential for on-site multiplex pathogen screening in veterinary diagnostics and epidemic control.
Developing flexible self-powered sensors capable of simultaneously converting biomechanical stimuli into electrical signals and supporting wearable motion analysis is of considerable importance for next-generation intelligent monitoring systems. In this work, a conductive montmorillonite/amphiphilic polyurethane (CMMT/APU) hydrogel-based triboelectric nanogenerator (CA-TENG) is constructed by integrating a conductive montmorillonite-modified hydrogel electrode with a contact-separation triboelectric configuration. Polytetrafluoroethylene (PTFE) and nylon are selected as the triboelectric layers, while the CMMT/APU hydrogel is employed as the flexible conductive electrode. Owing to the cooperative effect between conductive montmorillonite and the amphiphilic polyurethane network, the hydrogel exhibits good flexibility, structural stability, and mechanical adaptability, and the composition containing 5% CMMT presents the most suitable tensile performance for device fabrication. The optimized CA-TENG delivers a peak open-circuit voltage (V-OC) of 777V, a short-circuit current (I-SC) of 39 mu A, and a transferred charge (Q(SC)) of 250nC, together with a maximum output power of 598 mu W. Moreover, the device shows stable output under different working frequencies, separation distances, and humidity conditions, and it can effectively distinguish walking, running, jumping, and joint-bending motions, demonstrating strong potential for self-powered wearable-motion monitoring and biomechanical analysis.
Electrocatalytic water splitting is a key technology for green hydrogen production. It is severely limited by the sluggish kinetics of the oxygen evolution reaction and the hydrogen evolution reaction. Transition metal elements are abundant in the earth's crust and have tunable electronic structures. However, their catalysts exhibit insufficient active sites, poor electrical conductivity, and low stability. Electrospinning technology offers simple preparation, unique one-dimensional features, and high controllability over composition and morphology. Therefore, it has become an important platform for constructing high-performance electrocatalysts for water electrolysis.This review starts from the principles and preparation of electrospun nanofibers. The basic reaction mechanisms of HER and OER are introduced. Three core structural design strategies are systematically summarized: porous structures, hollow/core-shell structures, and heterojunction structures. How electrospinning technology regulates active site exposure, charge transport efficiency, and electronic structure of transition metal catalysts is deeply analyzed. Finally, the challenges and prospects for further development of electrospun nanofiber materials in water splitting electrocatalysts are discussed. Special emphasis is placed on theoretical calculation-assisted design and performance evaluation under high current densities.
To overcome the inherent agglomeration and potential nanotoxicity of inorganic UV filters, as well as the environmental concerns associated with organic absorbers, we present a bio-templated strategy utilizing natural dealkali lignin (DL) as a sustainable scaffold to direct the in situ growth of sheet-like CeO2, resulting in a well-defined two-dimensional CeO2/DL layered architecture. At an optimal DL mass ratio of 1.5%, the CeO2 nanosheets achieve uniform dispersion on the DL matrix, stabilized by hydrogen bonding and C-O-Ce interfacial linkages. The resulting composite exhibits strong ultraviolet absorption while retaining excellent visible transparency, achieving a Sun protection factor (SPF) of 8.9, representing a 2.1-fold and 1.7-fold enhancement over pristine DL and pristine CeO2, respectively. Moreover, the composite demonstrates remarkable antioxidant activity, with DPPH and hydroxyl radical scavenging efficiencies of 72% and 86%. This work establishes a viable pathway for designing natural, eco-friendly and high-performance next-generation UV-shielding materials.
Magnetic fluids (ferrofluids) are colloidal suspensions of magnetic nanoparticles in nonmagnetic carrier liquids. They respond rapidly and reversibly to external magnetic fields, showing coupled magnetic, thermal, hydrodynamic and optical behaviors. These properties support applications in biomedicine, mechanical engineering, environmental remediation, energy systems and magneto-optical devices. This review summarizes recent progress in these fields, focusing on working mechanisms, performance, limitations and key challenges such as colloidal stability, magnetic field control, scalable synthesis and safety assessment. Magnetic fluids have strong potential as multifunctional field-responsive materials, although broader practical use still depends on further improvements in stability, system design and application-oriented evaluation.
Magnetic carbon nanotubes (MCNTs), comprising carbon nanotubes and magnetic nanoparticles, exhibit significant potential for exploration and application due to their unique magnetic properties and high enrichment capability. This review summarizes recent advances in synthesis methods such as chemical vapor deposition, pyrolysis and hydrothermal techniques, which enable precise structural and magnetic control. MCNTs show significant potential in energy storage, magnetic solid-phase extraction, catalysis and sensors due to their high conductivity, large surface area and easy magnetic separation. However, Scalability and long-term stability remain key challenges, necessitating greener synthesis and deeper mechanistic understanding. This review provides timely insights into recent advances regarding on MCNTs.
The development of near-room-temperature magnetic refrigeration relies on magnetic materials with large entropy changes and broad operating ranges. Here, we report an interface functionalization strategy to construct La[Formula: see text]Ca[Formula: see text]MnO 3 @ZIF-67 composites via in-situ growth method. The introduction of ZIF-67 increased the specific surface area and created abundant mesopores. The composite with low ZIF-67 content (La[Formula: see text]Ca[Formula: see text]MnO 3 @ZIF-67-1) showed an enhanced maximum magnetic entropy change (3.66[Formula: see text]J[Formula: see text]kg[Formula: see text]K[Formula: see text] and relative cooling power (251.8[Formula: see text]J[Formula: see text]kg[Formula: see text] under 5[Formula: see text]T compared to the pure La[Formula: see text]Ca[Formula: see text]MnO 3 . However, higher ZIF-67 loading degraded magnetocaloric performance due to the dilution effect of the nonmagnetic phase. Notably, critical behavior analysis revealed a shift from the Ising model in pure La[Formula: see text]Ca[Formula: see text]MnO 3 , indicative of short-range interactions, to the mean-field model in composites, dominated by long-range interactions. This indicated that ZIF-67 suppressed critical magnetic fluctuations through interfacial coupling and physical isolation. This study confirmed that interfacial regulation using nonmagnetic porous metal-organic frameworks (MOFs) is an effective approach for optimizing the magnetocaloric properties of perovskite manganites and modulating their phase transition behaviors.
