Search Results (1,257)

Atomic layer deposition (ALD) has become a versatile technique for atomic-level material synthesis and surface modification, with broad relevance in applications such as energy storage devices, integrated circuits, and membranes. The deposition is governed by a multitude of factors spanning multiple length/time scales, ranging from macroscopic transport phenomena to atomistic surface reactions. Owing to the intricate process coupling across these scales, a comprehensive evaluation of atomistic behavior under flow conditions remains highly challenging. To address this issue, a multiscale integrated simulation framework is developed in which precursor transport within high-aspect-ratio nanochannels is explicitly simulated using a finite volume method (FVM) and subsequently coupled with kinetic Monte Carlo (kMC) simulations to evaluate film growth characteristics. Based on the FVM results, the spatiotemporal distribution of precursor partial pressures along nanochannels is extracted and employed as input for a lattice-based kMC model, enabling atomistic resolution of the ALD process over the full deposition cycle. By coupling these two scales, key deposition metrics including step coverage and its temporal evolution under varying partial pressure conditions are quantitatively obtained, together with atomic-level smoothness and vacancy ratio. The kMC simulations further enable detailed visualization of film growth behavior on substrates under different precursor partial pressure environments. The results indicate that, within the microstructure, even when the overall precursor exposure is comparable, films formed near the entrance exhibit superior surface structure, as evidenced by higher atomic-level smoothness and reduced vacancy ratio, compared to those at the bottom. This study provides an engineering-feasible framework for evaluating atomistic film properties in ALD processes by consistently integrating fluid transport and surface reaction kinetics. Full article

The Zeta-Minimizer Theorem provides a fully deductive variational foundation for the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. Starting from three primitive thermodynamic axioms and the helical geometry of the phase functional, a multi-extent dynamical system is constructed that simultaneously treats the electrochemical reaction coordinates and the adsorption extents of the participating species at the solid–electrolyte interface. The combined Hessian of the phase functional yields a complete spectrum of relaxation rates whose eigenvalues and eigenvectors emerge directly from the solid blackbox constants C_k and the helical partition functions of the reactive species. Adiabatic elimination of the fast surface modes produces an effective single-extent description in which voltage (or overpotential) appears as the conjugate variable, exactly analogous to the role of pressure in the corresponding gas-phase ammonia synthesis framework. The resulting nonlinear rate law is thermodynamically consistent at all conditions, recovers the Butler–Volmer and Tafel forms as well-defined limiting cases, and incorporates the effects of temperature, dilution, and catalyst-specific interface constants without empirical activation energies or adjustable reaction orders. The framework therefore unifies equilibrium, kinetics, and modal dynamics of HOR and ORR within a single variational structure, offering a parameter-light, first-principles alternative to classical empirical electrocatalytic rate expressions while preserving transparent contact with established limiting laws. Full article

Photocatalytic CO₂-to-CH₄ conversion is usually assessed through catalyst activity, selectivity, and methane formation rate, although the practical usefulness of the resulting gas stream also depends on methane recovery from CO₂-rich mixtures. Here, a phenomenological Langmuir–Hinshelwood reactor model was used to evaluate batch gas-phase CO₂ photoreduction under different reactor thicknesses, water-availability conditions, photocatalyst activities, and idealized methane-selective extraction configurations. The model considered competitive adsorption, transient gas-phase balances, finite or buffered water supply, and a lumped selective CH₄ extraction term. Under finite vapor inventory, water depletion limited reaction progress, particularly in thin reactors. Buffered-water operation increased CO₂ conversion and methane formation, while reactor thickness produced a trade-off: thin reactors favored apparent conversion and methane enrichment, whereas thicker reactors provided a larger CO₂ reservoir and higher cumulative methane formation. At the baseline kinetic condition, methane extraction strongly decreased the in-reactor CH₄ fraction but only modestly increased methane formation. When photocatalyst activity was increased, the non-membrane thin reactor reached a product-accumulation-limited regime, and methane-selective extraction became kinetically relevant. These results indicate that methane-selective extraction concepts should be evaluated not only as separation devices, but as conditional reactor-intensification tools whose relevance depends on water availability, reactor geometry, catalyst productivity, and product dilution. Full article

Background/Objectives: Dittrichia viscosa (L.) W. Greuter (Asteraceae) is a Mediterranean medicinal plant whose polar phenolic fraction remains insufficiently characterized. This study aimed to characterize the phenolic composition and evaluate the antioxidant, antimicrobial, and mechanistic bioactivity of aqueous and methanolic leaf extracts collected from the Rmilate Forest in Tangier, northern Morocco. Methods: Extracts were characterized by ICP-AES for elemental content and by HPLC-PDA-ESI-MS for phenolic annotation, and total phenolic, flavonoid, and tannin contents were quantified. Antioxidant capacity was assessed using DPPH, ABTS, FRAP, and ORAC assays. Antibacterial activity was evaluated against four reference strains, with time–kill kinetics and membrane integrity assays used to probe the mechanism of action, and antifungal activity was tested against dermatophytic and phytopathogenic fungi. Molecular docking against four bacterial, fungal, and antioxidant enzyme targets and ProTox-3 toxicity prediction were also performed. Results: ICP-AES revealed high concentrations of calcium (12,476.75 mg/kg) and potassium (29,699 mg/kg). The methanolic extract showed higher total phenolic (55.05 mg GAE/g), flavonoid (84.18 mg QE/g), and tannin (262.1 mg TAE/g) contents and superior antioxidant activity (DPPH IC₅₀: 0.090 mg/mL). Twelve phenolic compounds were tentatively annotated, including caffeic acid, caffeoylquinic acid derivatives, and quercetin/kaempferol glycosides. Antibacterial activity (MIC: 0.25–1 mg/mL) was consistent with cell envelope disruption, and up to 88% mycelial inhibition was achieved against Trichophyton rubrum. Docking ranked kaempferol-3-O-pentoside (−10.3 kcal/mol) among the top-scoring ligands, and the top compounds were assigned to toxicity class 5. Conclusions:D. viscosa is a promising source of bioactive phenolics for pharmaceutical and agrochemical development. Full article

Slow reaction kinetics of the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) under alkaline conditions limits the performance of anion exchange membrane fuel cells and water electrolysers (AEMFC and AEMWE). Consequently, high loadings of PGM metal-based compounds such as Pd-CeO₂ and PtRu are required to obtain competitive performance. The amount of precious metals present can be reduced by exploiting interaction with an active support material that tunes both hydrogen desorption and hydroxyl adsorption, processes that are key descriptors of HOR activity. In this work, NiWO_3−xC is prepared, composed of oxygen-deficient tungsten oxide (WO_3−x) doped with Ni nanoparticles and mixed with conductive carbon (50:50 wt%). This material is decorated with Pd nanoparticles (6.6 wt% Pd loading). Structural analysis (XRD, XPS, and HR-TEM/STEM) confirm a hybrid morphology of Pd nanoparticles deposited on both the Ni and W portions of the support. The HOR and HER activity was studied using electrochemical tests and compared to the performance of both a Pd/C standard with equivalent Pd loading (6.9 wt%) and the NiWO_3−xC support. The Pd-normalized exchange current densities for the HOR (I⁰) are 18.7 A g_Pd⁻¹ for Pd/NiWO_3−xC and 3.21 A g⁻¹ for Pd/C. The enhanced HOR activity of Pd/NiWO_3−xC translates to high power densities in AEM fuel cell tests with this catalyst applied to the anode electrode (up to 0.9 W cm⁻²). Full article

Ultrasound-induced cavitation is conventionally described through nonlinear bubble dynamics, acoustic pressure modulation, microbubble oscillation or collapse, local mechanical stress, thermal or chemical activation, and subsequent biological effects. In medical contexts, such cavitation-mediated processes are increasingly relevant to sonoporation, microbubble-enhanced drug delivery, sonodynamic therapy, and histotripsy. However, a compact phenomenological framework linking measurable cavitation dynamics to delayed, channel-specific biological outputs remains useful, particularly when different endpoints such as membrane permeabilization, reactive oxygen species generation, molecular uptake, and tissue fragmentation are considered together. In this work, a phenomenological relational–informational bridge model is proposed, in which therapeutic cavitation is interpreted as biological constraint focusing. The cavitation region and its adjacent biological microenvironment are represented as a localized, acoustically driven subsystem whose effective constraint state changes during bubble or microbubble oscillation and collapse. Bubble oscillation or collapse is represented as a rapid increase in constraint loading and informational action density, whereas medically relevant effects are modeled as relaxation of a transient high-tension state into bioactive output channels, including membrane permeabilization, reactive oxygen species generation, molecular delivery, and mechanical tissue fragmentation. The model couples the bubble or microbubble radius R(t) and collapse or oscillation velocity $\dot{R}\left(t\right)$, obtained experimentally or from Rayleigh–Plesset-type dynamics, to a dimensionless relational constraint parameter λ(t), an informational action density ${\mathcal{S}}_{rel}\left(t\right)$, a stored high-tension reservoir $E_{rel}\left(t\right)$, channel-specific motif populations $N_k\left(t\right)$, and measurable biological outputs $B_k\left(t\right)$. The construction is not intended to replace hydrodynamic, thermodynamic, sonochemical, or biomechanical models; rather, it provides a latent-variable layer that may organize how cavitation loading is converted into endpoint-specific biological responses. The framework yields testable expectations: biological response should correlate not only with acoustic pressure or minimum bubble radius, but also with the rate of constraint loading, reservoir buildup and depletion, relaxation-channel kinetics, and modifiers such as microbubble composition, tissue context, oxygenation, sonosensitizer availability, and molecular cargo. Ultrasound-mediated cavitation is therefore reframed as a bioengineering process in which acoustic exposure, bubble dynamics, transient energy localization, and biological endpoint formation are connected through a testable phenomenological bridge model. Full article

The rising prevalence of chronic kidney disease (CKD) has intensified the demand for innovative blood filtration therapies. Hemoperfusion, which integrates membrane filtration with adsorbent technologies to sequester circulating uremic toxins, represents a promising therapeutic alternative. In this study, polyethersulfone (PES)-powdered activated carbon (PAC) composite membranes were fabricated via nonsolvent-induced phase separation (NIPS), and the molecular weight of polyethylene glycol (PEG) was optimized as a hydrophilic pore-forming agent. Dope solutions were formulated with 15 wt.% PES, 1 wt.% PAC, and 10 wt.% PEG at varying molecular weights (200, 400, 600, and 1000 Da). Comprehensive characterization revealed that PEG molecular weight significantly dictates the structural and functional performance of the resulting composites. The PEG 600 Da variant achieved an optimal balance of properties, characterized by homogeneous PAC dispersion, a peak water flux of 420.88 LMH/Bar, a water contact angle of 37.11°, and a porosity of 74.74%, while maintaining a high Bovine Serum Albumin (BSA) rejection of 90.87%. While increasing PEG molecular weight generally enhanced permeability through the formation of an open pore architecture, a performance trade-off was observed beyond the 600 Da threshold due to increased dope viscosity and altered phase inversion kinetics. These findings suggest that PEG 600-optimized PES-PAC membranes offer a high-performance, affordable platform for advanced hemoperfusion applications. Full article

Molecularly imprinted membranes (MIMs) have demonstrated tremendous potential in the field of high-efficiency separation due to their specific molecular recognition capabilities. This review aims to elucidate the underlying mechanisms governing MIMs’ performance and, moving beyond traditional classification frameworks, systematically reconstructs the classification system for MIMs from the perspectives of the spatial distribution of imprinted sites, the chemical topology of the matrix, and mass transfer kinetics. The article focuses on the decisive influence of key physical parameters such as pore size, specific surface area, hydrophilicity/hydrophobicity, and swellability on separation efficiency. It provides an in-depth analysis of the spatial matching between pore size and target molecules, the nonlinear relationship between specific surface area and adsorption capacity, and the mechanisms by which mechanical strength and swelling behavior constrain the long-term stability of the membranes. Addressing the common bottlenecks faced by MIMs “high mass transfer resistance and poor accessibility of recognition sites” this paper critically summarizes cutting-edge morphological optimization strategies, such as multi-level pore construction, nanocomposite reinforcement, and surface topological engineering, aiming to elucidate how microstructural regulation can achieve a synergistic enhancement of both high throughput and high selectivity. Finally, by reviewing breakthroughs in MIMs applications for biomedical extraction and environmental pollutant remediation, this review not only clarifies the principles governing material suitability across different scenarios but also provides a systematic technical reference for the development of next-generation, high-performance, industrial-scale MIMs. Full article

This work analyzes protocol-dependent effects on the colloidal characterization and drug loading/release analysis of model thermosensitive PNIPAM-co-COOH microgels and shows how they can be quantified or minimized through targeted methodological refinements. Findings reveal that standard single-beam DLS underestimates the collapsed hydrodynamic radius by 18% at 43 °C due to thermal convection. After drift correction, 3D-DLS combined with SLS provides a consistent description of thermally induced collapse, pH-dependent swelling and core–corona structure. Regarding drug delivery, loading efficiency for Doxorubicin and 5-Fluorouracil is maximized near the volume phase transition temperature, where hydrophobic interactions are strongest. For release studies, dialysis is recommended, but free-drug blanks are required to account for membrane-induced delay and ensure accurate early kinetic profiles. By integrating TEM, AFM, SLS, DLS, NTA and LDE, this study establishes a robust framework for the colloidal characterization of thermosensitive microgels. These refinements reduce experimental bias and may be extended to related soft nanocarriers. Full article

The electrical behavior of cellular membranes plays a fundamental role in neuronal communication and in many physiological processes involving excitable cells. Mathematical modeling has become an essential tool for understanding the physical mechanisms underlying membrane dynamics and the generation of action potentials. The classical Hodgkin–Huxley model represents the cornerstone of conductance-based descriptions of neuronal activity, providing a quantitative framework in which ionic currents across the membrane are represented through nonlinear differential equations. Over the years, numerous extensions of this model have been developed in order to incorporate additional biophysical mechanisms, including dendritic processing, temperature dependence and electromagnetic effects. However, increasing experimental evidence has shown that neuronal activity is intrinsically stochastic due to the probabilistic nature of ion-channel gating and other microscopic processes. As a consequence, stochastic modeling approaches have been introduced to complement deterministic formulations and to capture the variability observed in real neuronal systems. In this review, we focus on a selected class of membrane models grounded in physical or biophysical principles, namely models that describe membrane dynamics through electrical analogies, conductance-based equations, stochastic channel kinetics, or memory-dependent circuit elements. These approaches can be viewed as extensions, reformulations, or generalizations of the Hodgkin–Huxley framework, developed to address specific physiological or computational limitations. The review focuses on the physical and mathematical structure of selected HH-derived models rather than on their experimental validation, and aims to compare representative physically motivated modeling strategies in terms of their assumptions, interpretability, and domains of applicability. Full article

Background: Processed extracellular lipid–protein preparations require rigorous analytical characterization to determine whether their compositional profile, processing stability, and short-term cellular compatibility are preserved across storage and handling conditions. Methods: In this study, we quantitatively characterized a processed phospholipoproteic secretome-derived formulation under fresh, concentrated, cryopreserved, and lyophilized conditions. Results: Label-free quantitative proteomic analyses performed using timsTOF Pro mass spectrometry coupled to dia-PASEF acquisition identified 574 human proteins across all experimental conditions following predefined analytical quality criteria. Comparative analyses demonstrated preservation of the overall structural proteomic profile following processing and storage procedures, with retention of membrane-associated and extracellular structural proteins consistently exceeding 90% relative to the fresh reference condition. Quantitative reproducibility remained high across all experimental groups, with coefficients of variation ranging from 3.0% to 4.5% and strong inter-replicate Pearson correlations. Principal component analysis, hierarchical clustering, peptide/protein overlap analyses, and differential expression profiling demonstrated limited proteomic divergence while preserving the majority of quantified proteins within conserved abundance ranges. Complementary real-time live-cell kinetic imaging performed in non-malignant dermal-derived cells using the IncuCyte^® S3 platform demonstrated stable short-term confluence kinetics and cellular viability exceeding 92% over 48 h across all evaluated formulations. No sustained proliferative suppression or detectable morphological evidence of cytotoxicity was observed. Collectively, these findings support the preservation of compositional stability, analytical reproducibility, and short-term ex vivo cellular compatibility across defined processing and storage conditions. These integrated proteomic and kinetic datasets provide a quantitative framework for the analytical evaluation of processed extracellular phospholipoproteic preparations, while functional barrier activity, membrane incorporation, lipid raft engagement, and long-term tissue-level effects remain to be addressed in dedicated future studies. Full article

In this study, composite nanofibrous membranes composed of poly(vinyl alcohol) (PVA), gelatin, and zein loaded with different contents of dihydromyricetin (DMY) were fabricated via electroblowing spinning (EBS). The effects of DMY content on the microstructure, physicochemical properties, mechanical strength, and functional performance of the membranes were evaluated. Scanning electron microscopy (SEM) analysis showed that the average fiber diameter increased from 174 ± 29 nm to 221 ± 35 nm with increasing DMY content, followed by a slight decrease at higher loading levels, indicating that DMY incorporation influences fiber morphology. Fourier transform infrared spectroscopy (FTIR) results suggested the presence of hydrogen bonding interactions between DMY and the polymer matrix. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results indicated changes in the physical state of DMY within the nanofibrous system as the loading content increased. All samples exhibited a typical two-stage release behavior, and the highest cumulative release (nearly 55%) was observed at a DMY loading of 22.5%, while further increasing the loading reduced the release efficiency to approximately 45%. The release profiles were well described by a first-order kinetic model. The composite membranes exhibited improved surface hydrophilicity, appropriate water vapor permeability, antioxidant activity, and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This study demonstrates the successful fabrication of DMY-loaded PVA/gelatin/zein nanofibrous membranes and provides preliminary insights into their structure–property–function relationships, release behavior, antioxidant activity, and antibacterial activity against representative bacteria, although further application-oriented validation is still required. Full article

Crystallization can be exploited as an architecture-forming step for polymer membranes because it builds a load-bearing semicrystalline scaffold while simultaneously defining amorphous regions that later become transport pathways. Herein, we quantify how thermal history programs isotactic polystyrene (iPS) crystallization and translate the resulting microstructures into membrane-relevant design rules. Lux-calibrated digitally extracted pixel intensity (DPI) from polarized optical microscopy provides a quantitative, spatially resolved crystallinity proxy; benchmarking against differential scanning calorimetry confirms that the DPI proxy exhibits the same onset, peak, and completion signatures under matched temperature programs. The DPI–DSC agreement yielded R² = 0.98 under matched programs. We compared crystallization initiated from molten and glassy states across a wide range of melt pretreatments and crystallization temperatures. Molten-state pathways display pronounced melt-memory behavior: modest changes in melt pretreatment shift induction time and half-time and drive textures from dense, fine spherulitic fields to sparse, coarser morphologies. In contrast, glassy-state crystallization largely suppresses melt history, yielding overlapping sigmoidal crystallinity curves and stable kinetic parameters consistent with relaxation-mediated nucleation. Avrami analyses indicate three-dimensional growth in both routes but highlight the strong melt-history sensitivity of apparent rate constants in the molten state. The crystallization rate and half-life show bell-shaped temperature dependence. Finally, saturated nucleation density correlates with the melting response, providing a practical link between kinetic observables and morphology. The processing–morphology map provides membrane-relevant design rules by linking thermal history to nucleation density and scaffold texture, which are expected to influence transport and mechanical stability in downstream membrane fabrication. In this study, “membrane architecture” is used in a pre-fabrication sense to denote the crystallization-programmed semicrystalline scaffold expected to govern subsequent pore-generation behavior and mechanical stability. Accordingly, the present work establishes a quantitative process–structure map for iPS scaffold design. Full article

Tea tree essential oil (TTO), extracted from Melaleuca alternifolia, is a terpene-rich botanical antimicrobial with demonstrated broad-spectrum activity against foodborne pathogens and spoilage microorganisms. Its bioactivity is principally attributed to oxygenated monoterpenes, most notably including terpinen-4-ol, γ-terpinene, and α-terpinene, whose structure–activity relationships govern interactions with microbial membranes and intracellular targets. This review provides a comprehensive, mechanistically grounded analysis of TTO as a sustainable antimicrobial platform for food preservation applications. The physicochemical determinants of TTO performance are critically assessed, encompassing chemotype-dependent compositional variability, hydrophobicity, limited aqueous solubility, and oxidative instability, with emphasis on how these properties constrain efficacy in complex food matrices. Antimicrobial mechanisms are systematically examined, including membrane permeabilization, disruption of cellular homeostasis, oxidative stress induction, and quorum-sensing interference. Focus is placed on nanostructured delivery systems, including nanoemulsions, biopolymer-based encapsulants, and hybrid nanocomposites, that improve physicochemical stability, modulate release kinetics, and potentiate antimicrobial activity. The integration of these engineered formulations into edible coatings, active packaging, and sanitation protocols across fresh produce, meat, and dairy systems is evaluated in the context of practical food safety applications. Translational limitations are addressed, including volatility, sensory incompatibility, regulatory constraints, and concentration-dependent cytotoxicity considerations. Collectively, this review positions TTO-based nanoformulations as a scientifically promising and technologically scalable approach to next-generation food preservation, while identifying critical gaps that must be resolved to support regulatory acceptance and commercial implementation. Full article

Mitochondria-targeting metal complexes (MTMCs) are a mechanistically distinct class of metallopharmaceuticals. Unlike first-generation platinum drugs that form nuclear DNA adducts, MTMCs exploit organelle-specific vulnerabilities such as hyperpolarised mitochondrial membrane potential (ΔΨm), elevated reactive oxygen species (ROS), limited mitochondrial DNA (mtDNA) repair capacity, and redox-dependent enzymes such as thioredoxin reductase (TrxR). We systematically searched PubMed, Web of Science, Scopus, and Google Scholar databases for studies published between 2016 and 2026, applying predefined inclusion criteria that included subcellular localization evidence and functional bioenergetic endpoints. The search identified 147 studies covering Pt(II/IV), Ru(II/III), Au(I/III), Ir(III), Os(II), Re(I), and V(IV/V) complexes and metal–organic framework nanoplatforms. Mechanistic evidence converges on four intramitochondrial target categories: inhibition of ETC (Electron Transport Chain) Complexes I/III with consequent ATP depletion; ROS overproduction, coupled with glutathione and TrxR depletion; outer mitochondrial membrane permeabilization and intrinsic apoptotic cascade activation; and mtDNA damage within a compartment limited to base excision repair. Multi-modal cell death—the co-occurrence of apoptosis, ferroptosis, necroptosis, and autophagic cell death—was a recurrent finding across the reviewed studies. This review thoroughly surveys the latest trends in MTMC drug design (metals, ligand structures, and mechanisms of action) and summarises analytical techniques for speciation, pharmacokinetics, safe monitoring, and resistance, while critically analysing translational barriers and clinical failures. To address the field’s inconsistent terminology, we introduce an explicit localization evidence hierarchy that distinguishes mitochondria-targeting complexes (through quantitative ICP-MS fractionation or co-localization with defined Pearson/Manders coefficients) from simply mitochondria-localising or mitochondria-perturbing agents, and we apply it throughout. We also point out that the idea of selectivity being purely driven by membrane voltage (ΔΨm) and thermodynamics is constrained by membrane and protein binding, as well as the transmembrane pH gradient, kinetic limitations, and demonstrated heterogeneity of cancer-cell membrane potential, and, as such, the functional mitochondrial effects must not be equated with mitochondrial accumulation. Since elemental quantification cannot distinguish intact complex from protein adducts and decomposition products, speciation-aware pharmacokinetics emerges as a prerequisite for a credible exposure–response interpretation. The translational progress will depend less on new chemotypes than on this analytical and pharmacokinetic rigour, together with organelle-level safety monitoring and biomarker-guided patient selection. Full article