Search Results (11,572)

In recent years, energy storage devices have had a lower energy density for supercapacitor devices. Fortunately, certain drawbacks limit the liquid-based battery-type aqueous zinc-ion hybrid capacitor electrodes. For this reason, zinc–manganese (Zn-Mn)-based zinc-ion hybrid supercapacitors (ZIHSCs) have been designed using a manganese-dioxide-functionalized carbon nanotube (MnO₂–f-MWCNT) battery-type cathode in a semi-solid gel–free-standing film electrolyte. Herein, as-prepared MnO₂–MWCNTs are synthesized and assembled for nanostructured cathode composite materials by a facile hydrothermal technique. In this work, MnO₂ nanorods with f-MWCNTs are applied to the electrode, resulting in a semi-solid-state gel film electrolyte realized by assembling the Zn-Mn hybrid capacitor. The materials’ physical–chemical conformation and their unique characteristics, crystalline structures, and different morphologies are studied through XRD, FE-SEM, FE-TEM, and XPS analysis. In this work, the design of major-source MnO₂-based materials for positive and battery-type zinc metal anode approaches, along with the electrochemical properties of MnO₂–MWCNT//Zn hybrid charge storage mechanisms, are evaluated. The coin-cell-type ZIHSC investigation of cyclic voltammetric (CV) curves and lower constant current charge/discharge (GCD) and electrochemical impedance (EIS) methods is also carried out. In addition, the maximum specific capacitance values, 339.98 mAh/g and 203.52 mAh/g, were observed for MnO₂–MWCNT//Zn and MnO₂//Zn at 0.2 mA/g, respectively. Finally, the higher cycling stability of MnO₂−f-MWCNT of a 94.15% capacity retention after 15,000 cycles was evaluated and compared to MnO₂//Zn of 73.05% retention in ZIHSC device applications. The assessment of electrochemical MnO₂ cathode-based Zn-Mn ZIHSC performance is applicable for future aqueous electrical energy storage devices. Full article

Nanostructured tungsten–copper (W–Cu) composites are promising materials for high-heat-flux components and advanced thermal management; however, their processing is limited by a high positive enthalpy of mixing of ~35.5 kJ/mol and weak interfacial bonding. This study provides a thermodynamic and kinetic justification for a technological route intended for 70W–30Cu and 75W–25Cu (wt.%) composites using high-energy mechanical activation and spark plasma sintering (SPS). CALPHAD-type calculations identified a critical copper activity plateau a_Cu ≈ 0.33 at 950 °C in the W-rich range, which favors the retention of submicron grains of 200–300 nm by limiting the chemical potential driving force for coarsening. Kinetic modeling via DICTRA predicted the formation of metastable interfacial diffusion zones with a characteristic width of 20–90 nm during short SPS holding times of 150–300 s, enabling the transition from mechanical interlocking to metallurgical bonding. Based on these calculations, a processing window of 950–1050 °C is proposed to achieve a target relative density of ≥97% and electrical conductivity of 35–45% IACS. The results provide a predictive framework for the experimental synthesis of nanostructured pseudoalloys with optimized conductive networks and reinforced tungsten skeletons. Full article

Rice husk (RH) is a renewable siliceous lignocellulosic waste providing a unique, greener and less toxic alternative to conventional synthetic polymeric precursors in the production of carbon-based materials for biomedical applications. In this work we studied the porous structure of RH-lignin-based activated carbon produced in the form of honeycomb carbon monoliths and assessed their potential as hemoadsorbents for blood purification in the treatment of patients with serious medical conditions, such as kidney failure and sepsis. To determine their clinical suitability for such an application, the hemocompatibility and cytotoxicity of the monoliths were investigated using the standard ISO guidelines. The monoliths did not cause any changes in the cell viability or cell lysis. High micro/mesoporosity and surface chemistry of the initial monolith-C, N- and P-doped nanostructured carbon honeycomb monoliths were established by low-temperature nitrogen adsorption (LTNA) studies, mercury porosimetry data (MIP), SEM/EDS analysis and FT-IR spectroscopy. The micro-mesoporous, activated carbon-based filtration/adsorbent prototype devices, in the form of three-dimensional (3D) carbon matrix, functionalized with ion-exchange amino- and phosphate groups and encased in polyolefin heat shrink cable sleeve, have been developed with the capacity to remove protein-bound uremic toxins (PBUTs), such us PCS and IS, as well as inflammatory cytokines (IL-6 and IL-8) from human plasma in a flowing model system. The ammoxidized monolith-N, derived from the monolith-C, had the highest removal efficiency (40.05% for PCS, and 28.4% for IL-6). By contrast, phosphorylated monolith-P demonstrated the highest removal efficiency (54.62% for IS, and 54.4% for IL-8), whilst the monolith-C has the lowest removal efficiency for these adsorbates. These results do not correlate with the LTNA and MIP study results, suggesting that the interaction of surface chemical functional groups with the solutes play key roles in the adsorption mechanism. The ion-exchange mechanism of PBUTs and inflammatory cytokine chemisorption by the monoliths, modified with surface N- and P-containing functional groups, has been proposed. Full article

By precisely controlling the growth temperature and coverage, we successfully synthesized a highly ordered zero-dimensional (0D) Sb₁₈ nanocluster and a one-dimensional (1D) Janus Sb nanochain on the Ag₂Sb/Ag(111) surface. Using scanning tunneling microscopy (STM) in combination with density functional theory (DFT) calculations, we characterized their atomic structures and found that the alloy substrate plays a significant role in stabilizing these configurations. Our findings not only demonstrate the feasibility of controllably synthesizing low-dimensional Sb nanostructures on metallic substrates but also provide valuable insights into their growth mechanism. Full article

Significant research efforts have recently focused on nanomaterial processing for gas sensors and related sensing applications. However, the major challenges in the field involve the choice of material for the sensing layer of the sensor device element, together with the right structure, assembly, and morphology through which the full sensing properties of the material can be realised. Herein, we critically review the hierarchical nanostructures of V₂O₅ nanomaterial for application in gas sensing technology. Beyond the sheet structure, which serves as the fundamental building block of the V₂O₅’smolecular arrangement, nanostructures ranging from nanobelts to nanowires, nanorods, nanoribbons, nanofibres, nanotubes, and thin films were discovered as preferred configurations and thermodynamically favourable structures, according to many synthesis processes. Ethanol (C₂H₅OH) and Nitrogen dioxide (NO₂) gases were identified as preferred molecules commonly detected by various V₂O₅ morphologies, with the nanotube structure showing preferential sensitivity and selectivity to C₂H₅OH. We also discuss perspectives from density functional theory (DFT) studies of V₂O₅ nanostructures and other (2D) materials structures for gas sensing applications. The studies highlight enhanced adsorption energy, increase conductivity, and band gap variation as a result of an upper shift in the Fermi level, all as a consequence of surface interaction between semiconductor crystal orientation and chemical molecules. Finally, our calculations of the optimised parameters for α-V₂O₅ orthorhombic structure showed good agreement with experimental and other theoretical data in the literature. The adsorption energy profile for NO₂ molecules revealed that the Ag-doped surface exhibits the most negative adsorption energy compared with the clean surface and other doped surfaces. Full article

Versatile nanostructured materials based on electrochemically etched porous silicon (pSi) are being developed, which have tuneable pore morphology and unique optical and electrochemical properties that enable their effective biosensing applications. It has been shown that fabrication parameters critically influence pore formation and sensor performance, yet challenges remain in reproducible synthesis, structural stability and device integration. Here we review the electrochemical etching synthesis of pSi and recent advances in pSi-based optical and electrochemical biosensors for detecting bacteria, biomolecules, and viruses. We highlight strategies such as surface functionalisation, incorporation of nanomaterials, and integration with microfluidic and lab-on-a-chip technologies that enhance sensitivity and response times by addressing mass transfer limitations. These developments highlight pSi’s potential as a low-cost, adaptable biosensing material with applications in clinical diagnostics and environmental monitoring, while mapping future directions to overcome current fabrication and stability challenges. Full article

Background and Objectives: The main neurodegenerative diseases (NDs)—Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS)—represent a growing global health burden with no available disease-modifying therapies. Curcumin, a polyphenol from Curcuma longa, is a promising candidate owing to its pleiotropic antioxidant, anti-inflammatory, and neuroprotective profile observed mainly in preclinical models, but the poor oral bioavailability (<1%) and negligible BBB penetration (<0.1%) have substantially limited curcumin’s clinical translation. The objective of this work was to critically examine the therapeutic potential of curcumin in NDs, focusing on advanced drug delivery systems (DDSs) designed to overcome its pharmacokinetic barriers. Methods: This is a narrative, non-systematic review of PubMed/MEDLINE, Scopus, and Web of Science. The review is organized around five complementary thematic areas selected to span the full translational pipeline of curcumin in neurodegeneration, from mechanistic rationale to clinical applicability: (1) molecular mechanisms, addressing the pleiotropic activities that justify therapeutic interest; (2) pharmacokinetic barriers, the principal obstacle to clinical translation; (3) the evolution of drug delivery systems (DDSs), documenting the technological strategies developed to overcome these barriers; (4) disease-specific applications, evaluating the available evidence across the four main NDs; and (5) translational limitations, identifying the methodological and regulatory gaps that must be closed to enable clinical implementation. Results: Curcumin exhibits neuroprotective activity in preclinical models of the four NDs analysed, acting on six interconnected mechanisms and the gut–brain axis. Four generations of DDSs have been developed, from phytosomes and clinically used lipid dispersions (Meriva^®, BCM-95^®, Longvida^®, and Theracurmin^®) to fourth-generation systems (biomimetic nanoparticles, MOFs, microneedles, 3D scaffolds, hydrogels, and carbon dots) that substantially increase the bioavailability in preclinical studies. Combination strategies, such as curcumin with resveratrol and dutasteride, show preliminary clinical signals in ALS. However, clinical translation remains limited: over 80% of positive animal findings have not been replicated in humans, formulation characterization is frequently incomplete, and most trials lack CNS-exposure biomarkers. Importantly, most of the reported bioavailability claims are based on total curcumin measurements (parent aglycone plus its inactive Phase II conjugates) rather than the active aglycone alone, a methodological limitation that should be considered when interpreting the magnitude of the bioavailability improvements reported for novel formulations. Conclusions: Curcumin exhibits pleiotropic neuroprotective activity in preclinical models of AD, PD, MS, and ALS, mediated by interconnected antioxidant, anti-inflammatory, anti-amyloidogenic, mitochondrial, and gut–brain axis mechanisms. However, its poor systemic bioavailability (<1%), minimal blood–brain barrier penetration, and extensive first-pass metabolism have limited clinical translation. Advanced drug delivery systems (including lipid-based carriers (liposomes, solid lipid nanoparticles, and nanostructured lipid carriers), polymeric nanoparticles (PLGA and chitosan), and bioinspired vesicles (exosomes)) are essential in order to overcome these barriers. Nevertheless, the formulation heterogeneity, limited long-term safety data, and reliance on preclinical models remain major obstacles; a definitive clinical translation will therefore require well-characterized formulations validated in phase II/III trials with cerebrospinal fluid exposure biomarkers, the pharmacokinetic monitoring of active aglycone (rather than total curcumin including inactive conjugates), and adaptive trial designs in neurological populations. Full article

Bioactive polysaccharides (e.g., fucoidan, β-glucans, and medicinal plant polysaccharides) contain functional groups that interact with drug molecules, and some also retain their own biological activities. Through reversible noncovalent interactions, they can associate with small-molecule drugs and form supramolecular nanocomplexes, defined here as nanoscale assemblies in which the polysaccharide is a main structural component and its association with the drug contributes to assembly or drug retention. Multicomponent composites and bulk local matrices are discussed separately as related or extended systems. The review covers hydrogen bonding, hydrophobic association, electrostatic complexation, π–π stacking, and the cooperation among these interactions, together with the effects of pH, ionic strength, concentration, and solvent composition. Nanoprecipitation/solvent exchange, polyelectrolyte complexation, direct aqueous self-assembly, and microfluidic-assisted assembly are compared with respect to nanostructure formation, process control, and reproducibility. Molecular, colloidal, solid-state, and computational evidence is examined together when interpreting structure–assembly–performance relationships. Reported advantages include improved drug dispersibility, colloidal stability, release control, bioavailability, cellular uptake, biodistribution, and safety. In some systems, the polysaccharide itself may also contribute to therapeutic effects in tumors, inflammatory diseases, and wound healing. Related local-matrix systems are considered separately. Further development of these nanocomplexes will require better quantitative analysis of assembly mechanisms, more consistent polysaccharide characterization, careful biocompatibility assessment, scalable preparation, and longer-term safety evaluation. Full article

Metal–organic frameworks (MOFs) have significant potential in electrochemical sensors, but the guest molecules and residual solvents in the pores often block the active sites and limit the reaction kinetics. One-dimensional nanostructures can provide direct conduction pathways and shorten ion diffusion distances, thereby enhancing electron transport and electrode contact. Meanwhile, fluorine-incorporated MOF materials leverage the high electronegativity of fluorine to substitute oxygen, suppress oxidation to widen the voltage window, and improve stability through enhanced hydrophobicity. In this work, 4-fluorosalicylic acid (4FSA) was used as the ligand and benzimidazole (Bim) was introduced to adjust the coordination environment, and one-dimensional Bim4FSA-MOF nanorods were successfully constructed. While the guest molecules were largely removed, the nickel sites were thereby activated and the pore size was enlarged. Due to the synergistic effect of one-dimensional nanostructure-promoted electron transport and the Ni(OH)₂/NiOOH dynamic active center, the B-250 composite exhibited excellent performance in a glucose electrochemical sensor. The optimized sensor delivered a detection limit of 0.022 μM and a detection time of 0.9 s, along with a sensitivity value of 2986.45 μA mM⁻¹ cm⁻², which provides a new strategy for the design of efficient MOF-based electrochemical sensor interface. Full article

Surface-enhanced Raman scattering is highly promising for trace molecular detection but requires substrates with both ultrahigh sensitivity and macroscopic uniformity. Current bimetallic nanostructures struggle to achieve large-area structural reproducibility and high-density “hot spots” due to the lack of precise spatial control over nanoparticle arrangement and the random distribution of nanogaps, which severely limits their quantitative reliability in realistic applications. Here, we developed a simple and scalable method to fabricate a highly ordered Au/Ag composite nanoshell array via combining the gas–liquid interface self-assembly and ion sputtering. This prepared substrate is featured by abundant nanoscale openings, crevices, and interfacial junctions. The Au/Ag composite nanoshell array achieves an ultra-low limit of 10⁻¹¹ M for the standard probe Rhodamine 6G. The highly ordered array also ensures advanced large-area signal reproducibility with a relative standard deviation of 6.1%. This work successfully balances the large-area uniformity and high sensitivity in SERS detection. It also provides a robust and reliable plasmonic platform for practical food safety analysis and environmental monitoring. Full article

A miniature label-free biosensor based on a chemically etched single-mode optical fiber (SMF) is reported for the detection of matrix metalloproteinase-8 (MMP-8), a salivary biomarker of active periodontitis with a clinical decision threshold of 20 ng/mL. Fibers etched in 48% hydrofluoric acid to a waist diameter of 16.0 ± 1.4 µm gave a mean refractive index (RI) sensitivity of 376.8%/RIU and an RI limit of detection (LOD) of 5.9 × 10⁻⁴ RIU. Fibers were tested with MMP-8 spiked into phosphate-buffered saline (PBS) and into saliva over 0–200 ng/mL using a post-rinse protocol with per-fiber matrix subtraction. Dose–responses followed a Langmuir isotherm (Kd = 7.1 ng/mL in PBS, 12.7 ng/mL in saliva), with cohort LODs of 0.043 and 0.52 ng/mL, both well below the threshold. MMP-9 (100 ng/mL) and human serum albumin (1 mg/mL) gave negligible responses (≤2.7%, versus 68.2% for MMP-8 at 100 ng/mL); antibody immobilization was confirmed by confocal immunofluorescence. A commercial sandwich ELISA on the same spike series gave a matched-matrix LOD of 41.1 ng/mL, nearly two orders of magnitude higher. This performance requires no metal coating, nanostructuring, label, or signal amplification, only a single wet-etching step on stock telecommunications fiber. Full article

It is of utmost importance to investigate the effect of carbon-based nanostructures on plants in order to fully unlock their potential for enhancing productivity and stress tolerance. In this study, a comprehensive assessment of the effect of pre-sowing treatment of wheat seeds with fullerenol (PHF [C₆₀(OH)₂₄], 0.1 mg/L) solution on a number of physiological and biochemical parameters in seedlings under optimal and low temperature (LT, 4 °C, 5 days) conditions was carried out. Seedlings primed with PHF differed from control variant in accelerated growth (by 27–34%), increased biomass (by 10%), larger area of chloroplasts and mesophyll cells (by 40%), more intensive photosynthesis (1.5-fold higher), increased content of chlorophyll a (by 11%), proteins (by 28%) and ascorbic acid, reduced level of MDA and H₂O₂, decreased SOD activity (by 45%) and a higher level of COR-genes (WCOR15, WCOR726) transcription (p < 0.05). Under LT conditions, PHF nanopriming enhanced photosynthesis intensity by increasing chloroplast area, content of chlorophyll b (by 22%) and proportion of chlorophyll in LHC (by 11%), as well as increasing the expression of RBCS (fourfold higher), content of proline, and COR-gene expression (p < 0.05). All these changes are adaptive and expand the adaptive potential of plants. It is concluded that nanopriming with PHF is an active metabolic modulator that reduces ROS generation and enhances cold acclimation of wheat. Full article

This paper investigated the lubricant stability and anti-biofouling performance on slippery liquid-infused nanostructured surfaces (SLIPSs) using thermodynamic and interfacial energy analyses. ZnO nanorods were synthesized on indium tin oxide substrates with and without a ZnO seed layer by electrochemical deposition and subsequently infused with PDMS-based silicone oil. The seed-layer-assisted growth produced densely packed and vertically aligned ZnO nanorods. Interfacial energy analysis showed that the resulting SLIPSs satisfied the criterion for resistance to water-induced lubricant displacement (ΔE₂ = 64.14 mJ·m⁻²), indicating effective lubricant retention, whereas non-seeded surfaces exhibited reduced lubricant stability. Consistent with this prediction, the seed-layer-assisted SLIPSs retained droplet mobility following spin testing at 2500 rpm, although the reduced sliding velocity indicated a decline in slippery performance. Anti-biofouling evaluation using Escherichia coli (XL1-Blue) revealed that the SLIPSs effectively suppressed bacterial attachment, reducing surface coverage to below 0.3% after 24 h of incubation. In comparison, the pristine ITO and ZnO nanorods exhibited values of 50.8% and 54.6%, respectively. Subsequent surface free energy analysis demonstrated that lubricant infusion reduced the work of adhesion to 77.92 mJ·m⁻². These findings provide insight into the interfacial interactions governing lubricant retention and bacterial attachment on SLIPSs. Full article

Ti–6Al–4V alloy is widely used in aerospace and other high-performance engineering components, but its service reliability is often constrained by surface-initiated fatigue, fretting damage, wear, and corrosion. Ultrasonic surface rolling process (USRP) couples a static rolling force with high-frequency mechanical impacts to introduce severe plastic deformation while retaining relatively low surface roughness, thereby producing a gradient-strengthened surface layer. This review systematically summarizes advances in USRP strengthening of Ti–6Al–4V alloy within a “process–microstructure–surface integrity–service performance” framework. The effects of static load, ultrasonic amplitude and frequency, feed rate, spindle speed, processing passes, treatment temperature, and lubrication conditions are first compared. Particular attention is then paid to the mechanisms governing dislocation multiplication and rearrangement, grain subdivision, gradient nanostructure formation, the responses of the α and β phases, deformation-induced phase transformation, and the evolution of depth-dependent residual compressive stress. The intrinsic relationships between these mechanisms and surface roughness, hardness, strengthened layer depth, wear and corrosion resistance, fatigue performance, and fretting fatigue performance are subsequently clarified. Control strategies involving electropulsing, laser/temperature assistance, deep cryogenic treatment, and coating combinations are further reviewed, together with methods for contact dynamics analysis, residual stress prediction, and data-driven optimization. The combined evidence indicates that the performance gains from USRP are jointly controlled by surface defects, gradient microstructure, and residual compressive stress; excessive load, processing passes, or heat input may weaken or even reverse the fatigue benefit because of defect accumulation, gradient mismatch, and residual stress relaxation. Current limitations include inconsistent reporting of process parameters, difficulty in quantitatively separating the contributions of different strengthening mechanisms, insufficient investigation of residual stress stability, and limited validation on complex components. Full article

Soybean hulls, an abundant agro-industrial by-product, were valorized as a renewable cellulose source for nanocellulose production. Cellulose isolates were obtained by alkaline treatment followed by bleaching with sodium chlorite (NaClO₂) or hydrogen peroxide (H₂O₂) and subsequently used to produce cellulose nanocrystals (CNC) and TEMPO-oxidized cellulose nanofibrils (CNF). Process efficiency and the structural and rheological properties of the resulting nanocelluloses were systematically compared. Sodium chlorite bleaching removed lignin and hemicellulose more effectively than hydrogen peroxide treatment, yielding isolates with higher cellulose content. Consequently, CNC_NaClO2 exhibited greater aspect ratio, higher crystallinity, and improved network-forming ability. Their suspensions showed pronounced viscoelastic and thixotropic behavior (G′ > G″), whereas CNC_H2O2 displayed lower moduli and nearly Newtonian flow. CNF suspensions exhibited dominant elastic behavior and gel-like consistency regardless of bleaching method, although this effect was stronger for CNF_NaClO2 due to the formation of longer, more entangled fibrils. FTIR confirmed the high purity of all nanocelluloses, while negative surface charge ensured colloidal stability. Overall, bleaching chemistry governed nanocellulose morphology and rheological performance, enabling tailored functional properties. By maintaining a constant biomass source and identical nanostructure production conditions while varying exclusively the bleaching agent, this study implements a controlled-variable design that rigorously isolates the effect of bleaching treatment. This systematic comparative framework provides methodological robustness rarely achieved in previous studies, where differences in raw materials or processing conditions often confound interpretation. Full article