Search Results (3,192)

Multifunctional nano-contrast agent carriers are redefining molecular imaging by combining high-fidelity visualization with targeted delivery, controlled release, and, increasingly, therapeutic action. This review encompasses the development of nano-contrast platforms from conventional dendrimer, liposome, chitosan, and silica systems to modular nano-contrast platforms for multimodal, multi-parametric, and activatable imaging in clinically relevant environments. We dissect engineering strategies that govern surface chemistry, ligand organization, stimulus responsiveness, and microenvironmental sensing, and relate them to theranostic performance, immune system engagement, and quantitative image readouts. Biodistribution, pharmacokinetics, and safety are discussed from both classical and model-informed perspectives, with design principles that favor predictable behavior, manufacturability, and regulatory acceptance. Current clinical translation, regulatory pathway evolution, and market dynamics are critically reviewed to elucidate that a few nano-contrast agents have reached patients despite a widespread experimental landscape. Finally, we discuss emerging trends, including biomimetic and ultrasmall carriers, metal–organic and hybrid frameworks, AI-assisted design, digital twins, and precision medicine workflows, which are likely to shape the next-generation nano-contrast theranostics. By systematically relating material selection and carrier architecture to imaging function and translational limitations, this review suggests concrete research priorities for taking nano-contrast agents from sophisticated prototypes to robust, patient-tailored tools. Full article

Three Pt/CeO₂ catalysts were prepared via thermal reduction with different Pt introduction sequences: impregnation (IM), reverse impregnation (RIM), and reduction–co-assembly (RCM). Their physicochemical properties and catalytic oxidation activity for toluene were compared over IM-prepared Pt_pre/CeO₂, RIM-prepared Pt/CeO_2pre, and RCM-prepared Pt_pre/CeO_2pre. Different Pt loading methods affect the distribution, particle size, chemical state of Pt, and the metal–support interaction on the catalyst surface. Among them, the Pt_pre/CeO_2pre catalyst exhibits a high oxygen vacancy concentration and the best low-temperature reduction characteristics. Its high Ce³⁺/Ce⁴⁺ ratio, lattice oxygen content, and the content of Pt with active valence states (Pt⁰, Pt²⁺) are all conducive to the catalytic oxidation of toluene. The content of different valence states of Pt, dispersion degree, and cluster size of Pt on the catalyst, as well as oxygen vacancies and the valence state of Ce, were evaluated by XPS, Raman, H₂-TPR, in situ infrared, TEM, and N₂ adsorption–desorption tests, clarifying the reasons for the high activity of the catalyst. This provides an experimental basis and contributes strategies for the development of noble metal-loaded oxide catalysts prepared from metal–organic frameworks as precursors. Full article

Aerospace die forgings are safety-critical structural products whose service performance is governed by coupled microstructural evolution across multiple length scales rather than by any single descriptor. This review critically synthesizes recent progress in multiscale characterization and process–structure–property analysis of aerospace die forgings, with emphasis on forged titanium alloys, wrought nickel-based superalloys, and high-strength aluminum alloys. A practical framework is first established by linking macroscale metal-flow integrity and defect control with mesoscale gradients, microscale grain-boundary and texture evolution, and nanoscale precipitation, segregation, and interface states. The principal characterization routes are then discussed, including X-ray diffraction, EBSD/3D-EBSD, TEM/STEM, atom probe tomography, tomography-based defect evaluation, and correlative workflows. The alloy-specific sections are organized around mechanisms and property consequences rather than isolated micrographs. Finally, the review discusses how multiscale descriptors can support crystal-plasticity, phase-field, cellular-automata, and ICME-oriented modeling, and identifies future priorities in three-dimensional characterization, quantitative descriptor extraction, uncertainty-aware modeling, environmental degradation assessment, and closed-loop process optimization. Overall, the performance of aerospace die forgings is shown to depend on coordinated control of phase stability, grain-boundary network evolution, precipitation state, defect population, and location-dependent heterogeneity across the full manufacturing route. Full article

Developing earth-abundant photocatalysts that operate efficiently under visible light remains a central challenge in sustainable aerobic oxidation chemistry. We synthesized a binuclear cobalt(II) structure (Co₂) in which two redox-active metal centers are bridged by a polypyridine scaffold to integrate light-harvesting and catalytic functions within a single low-nuclearity unit. The complex exhibits a strong absorption band below 450 nm, undergoes facile charge separation upon photoexcitation, and channels molecular oxygen (O₂) toward superoxide radical anion (O₂^•–) under blue-light irradiation. Spectroscopic and mechanistic studies indicate that the polypyridine framework governs photon capture and excited-state delocalization, whereas the proximal Co(II) sites mediate the subsequent single-electron transfer to O₂. Driven by this dual-site synergy, Co₂ selectively oxidizes a broad scope of thioethers to the corresponding sulfoxides in yields exceeding 95%, with no over-oxidation to sulfones detected. The catalyst retains its structural integrity over five successive runs without measurable activity loss. By confining complementary photophysical and redox functions within a discrete bimetallic unit, this work establishes a design strategy for noble-metal-free, visible-light-driven organic transformations. Full article

Wastewater containing heavy metals and dyes poses serious environmental risks. This study developed a multifunctional composite by coating polyurethane foam (PUF) with milled activated carbon (mAC) and a zirconium-based metal–organic framework (Zr-MOF) for the simultaneous removal of hexavalent chromium (Cr(VI)) and Congo red (CR). The composite was synthesized using a hydrothermal method to grow Zr-MOF on the surface. The SEM analysis confirmed the successful incorporation of mAC and surface modification with Zr-MOF, which resulted in increased surface roughness and porous morphology. XRD and FTIR confirmed the presence of organic ligands connected to the metal structure and the functional groups of each component in composite materials. The optimum conditions for Zr-MOF/mAC/PUF adsorption (nearly 100% removal) in the binary Cr(VI)/CR solution (50 mg/L each) were 25 °C, pH 9, and 150 rpm for 24 h. The Zr-MOF/mAC/PUF was hydrophilic with a swelling ratio of 2.64 g/g. The thermodynamic investigation of Zr-MOF/mAC/PUF resulted in 141.6218 kJ/mol for Cr(VI) and 166.111 kJ/mol for CR of ΔH° (rapid adsorption), negative ΔG° (spontaneous adsorption), a high positive value of ΔS° (disorder structure) and low activation energy (approximately 2.5 to 2.8 kJ/mol). After analyzing the isotherm and reaction kinetics, the possible mechanism could be endothermic physicochemical adsorption and pseudo-second-order kinetic behavior, with electrostatic attraction and diffusion control. The study of 6-times-reused Zr-MOF/mAC/PUF adsorption identified as a decrease of 7.55 percentage point without changing notable morphology and functional groups, based on SEM and FTIR. Full article

We report the study of Cur@HKUST-1 composites, obtained through one-pot infiltration of HKUST-1 with curcumin (Cur) as a guest-sensitizing molecule. Cur features a HOMO energy above the valence band (VB) of HKUST-1, enabling modulation of the electronic structure of the host framework by introducing additional energy states within the bandgap. Structural characterization, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), confirmed successful guest incorporation and preservation of HKUST-1 crystallinity. An initial Cur amount of 50% (relative to the BTC linker) was added to the synthetic mixture, and differential UV-vis analysis has shown an infiltration efficiency of 28.0%, corresponding to an infiltration degree of 14% in the Cur@HKUST-1 composite, highlighting a challenging loading process, primarily due to the size and conformations of the Cur structure. Textural analysis revealed a reduction in surface area and pore volume, consistent with a high degree of guest infiltration. Optical properties evaluated by diffuse reflectance UV-vis spectroscopy revealed new absorption bands and a notable decrease of 1.83 eV in the bandgap energy from 3.68 eV (HKUST-1) to 1.85 eV (Cur@HKUST-1) due to guest molecule infiltration. Density functional theory (DFT) calculations supported the experimental findings, showing that guest HOMOs promoted the formation of a new valence band (VB), while the original VB remains lower in energy. Density-of-states analysis confirmed that the new VB originates from 2p orbitals belonging to the guest, while the conduction band remains predominantly Cu-based from the HKUST-1 framework. Photoelectrochemical characterization revealed that the guest-modified material exhibits an enhanced photocurrent response compared to HKUST-1. Cur@HKUST-1 displayed higher stability and stronger photocurrent density, attributed to its narrower bandgap and increased charge carrier density. These results demonstrate the potential of rational guest selection to engineer band structure and improve the light-harvesting performance of MOFs in solar-driven applications. 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

The formation of peptide bonds under prebiotic conditions represents a major challenge due to both thermodynamic and kinetic constraints, particularly in aqueous environments where condensation reactions are disfavored. Mineral surfaces have long been proposed as key contributors to overcoming these limitations by providing structured and reactive interfaces that promote molecular organization and facilitate chemical transformations. In this context, hydroxyapatite emerges as a particularly promising system due to its structural versatility, surface heterogeneity, and ability to interact with a wide range of organic molecules. Its capacity to support adsorption, interfacial organization, and dynamic interactions makes it a promising platform for surface-mediated prebiotic chemistry. Furthermore, the incorporation of metal centers, especially zirconium-based species, introduces additional catalytic functionalities that can enhance bond activation and enable cooperative reaction mechanisms. The combination of mineral surfaces and metal-based catalysis thus provides a framework for understanding how complex chemical processes could have emerged under prebiotic conditions. Particular attention is given to hybrid hydroxyapatite–zirconium systems as multifunctional catalytic platforms integrating adsorption, activation, and spatial organization. Finally, the role of dynamic environmental regimes, including gradients, cyclic processes, and non-equilibrium conditions, is considered as a critical factor in sustaining chemical reactivity and promoting increasing levels of molecular complexity. Together, these elements support a scenario in which surface-mediated processes played a central role in the emergence of peptide-like structures and early protometabolic systems. Full article

The recovery of low- and medium-temperature waste heat using Organic Rankine Cycles (ORCs) is increasingly important for improving the efficiency and sustainability of industrial and energy systems. In compact ORC turboexpanders, high specific power output and large pressure ratios often require single- or two-stage turbines operating in transonic or supersonic regimes. Under these conditions, stator blade design is complicated by strong compressible-flow effects and, for organic working fluids, by real-gas thermodynamic behavior. Conventional supersonic stator design methods, such as the method of characteristics, are mainly applicable to the diverging supersonic portion of the blade passage, while the converging region is typically defined using empirical or heuristic prescriptions. This paper presents a physics-informed neural-network-based design method for supersonic turbine stator blades. The proposed framework generates the complete inter-blade passage, including both the converging and diverging regions, starting from a prescribed mean-line geometry and Mach number distribution. The velocity field is obtained by solving the governing equations of steady, inviscid, adiabatic, irrotational compressible flow within a PINN formulation. A hard boundary-condition strategy is used to impose the specified mean-line velocity distribution exactly, while real-fluid thermodynamic effects are incorporated through lookup tables for the speed of sound and density. The blade contours are then reconstructed from stream-function isolines predicted from the computed velocity field. The method is demonstrated for two working fluids: air, treated as a perfect gas, and toluene undergoing transcritical expansion. The resulting blade passages are first validated using inviscid CFD simulations, which show close agreement between the prescribed and computed mean-line Mach number distributions. Turbulent CFD simulations of the final blade cascades confirm smooth acceleration through the inter-blade passage, with no strong internal shocks and only weak fishtail shocks downstream of the trailing edge. For both fluids, the post-expansion ratio is approximately unity and the exit flow angle remains close to the prescribed blade metal angle, indicating well-matched supersonic stator designs. The results demonstrate that the proposed PINN-based design method provides a physically consistent approach for generating supersonic stator blade profiles for both ideal-gas and real-gas turbine applications. Full article

As a sustainable alternative to fossil fuels, geothermal energy plays a critical role in the global shift toward carbon neutrality. However, the economic extraction of heat is frequently hindered by poor-reservoir permeability, often exacerbated by mineral scaling and particulate clogging during long-term operation. This review provides a comprehensive synthesis of acidization technologies, emphasizing their mechanisms for enhancing injectivity and productivity in diverse geothermal settings. This study scrutinizes the chemical interaction between varied acid systems ranging from conventional mineral acids to solid organic acid blends and the complex geological conditions of volcanic and sedimentary reservoirs. Furthermore, the paper delineates the evolution of geothermal energy development methods, such as matrix acidizing and hydraulic fracturing synergy (multi-stage acid fracturing), alongside metal corrosion inhibition and effluent scale treatment. By integrating empirical field data with theoretical geochemical modeling, this review provides an in-depth analysis of the acid fracturing mechanisms within coupled thermal–hydraulic–mechanical–chemical (THMC) fields. It further identifies the persistent challenges of high-temperature stability and deep-seated flow path diversion. Ultimately, this paper proposes a roadmap for next-generation “smart” acidizing fluids, aiming to provide a robust framework for optimizing geothermal heat mining and ensuring the longevity of enhanced geothermal systems. Full article

Landfill leachate represents a long-term source of contamination that may significantly affect groundwater and receiving water bodies through the migration of organic, inorganic, and toxic pollutants. This study evaluated the long-term migration of landfill leachate and its potential environmental impacts using the LandSim Release 2 probabilistic software model applied to two municipal waste landfills in the Republic of Serbia: the regional sanitary landfill “Gigoš” in Jagodina and the sanitary landfill “Meteris” in Vranje. The modelling framework integrated laboratory leachate analyses, hydrogeological conditions, engineered barrier system characteristics, and receptor-oriented contaminant transport assessment. Model validation was performed through comparison of simulated and laboratory-measured concentrations. Two scenarios were analyzed for each site: an engineered sanitary landfill scenario with a functional containment system and a conservative barrier-failure scenario representing complete loss of engineered barrier functionality. Ten representative leachate parameters were included, covering nitrogen compounds, inorganic ions, toxic substances, and heavy metals/metalloids. The results showed that engineered protection systems significantly delay contaminant migration and reduce receptor concentrations, while barrier-failure conditions lead to earlier pollutant breakthrough and higher environmental risk. The simulations demonstrated that under the engineered sanitary landfill scenario, receptor concentrations of all analyzed contaminants remained below the corresponding maximum allowable concentrations, with contaminant migration occurring only after several centuries. In contrast, the conservative barrier-failure scenario resulted in substantially earlier contaminant breakthrough, with nitrogen compounds and phenols representing the greatest environmental concern due to their rapid migration and exceedance of regulatory thresholds, while the “Meteris” landfill generally exhibited higher receptor concentrations than the “Gigoš” landfill. These findings highlight the importance of predictive modelling and long-term monitoring for sustainable landfill management and groundwater protection. Full article

A novel composite catalyst for photothermal CO₂ cycloaddition was developed by integrating the ionic liquid 1-ethylpyridinium bromide (EPB) with a copper-based metal–organic framework (HKUST-1). HKUST-1 was synthesized via a hydrothermal method and functionalized with EPB through a wet impregnation strategy to enhance its catalytic performance. Under xenon lamp irradiation and optimized conditions (80 °C, 1 MPa CO₂ pressure, 12 h, and 0.07% mol of TBAB bromide as a co-catalyst), the HK@EPB composite exhibited outstanding performance in catalyzing the conversion of CO₂ and various epoxides into cyclic carbonates. The exceptional catalytic activity arises from a synergistic multicomponent mechanism: the incorporation of EPB not only enhances CO₂ adsorption capacity but also provides photothermal energy for the reaction; simultaneously, EPB dissociates bromide ions to effectively initiate epoxide ring-opening. In particular, propylene oxide achieved a selectivity of 95% for the desired cyclic carbonate, surpassing most previously reported MOF-based catalysts. This system enables efficient catalysis under mild conditions through the synergistic contributions of the high CO₂ adsorption capacity and Cu²⁺/Cu⁺ redox-mediated electron transfer of HKUST-1, the provision of nucleophilic Br-species from EPB to promote epoxide ring-opening, and the cooperative effect of TBAB. This study demonstrates that ionic-liquid-functionalized MOF composites can serve as sustainable and versatile catalytic platforms, offering an environmentally friendly pathway for large-scale CO₂ utilization. Full article

Adsorption therapies in hemodialysis have emerged as an innovative approach for removing protein-bound uremic toxins (PBUTs). The present work focuses on the enhancement of the adsorption capacity of hemodialysis membranes through the incorporation of Metal–Organic Frameworks (MOFs). The removal capacity of PBUT p-cresyl sulfate by cellulose acetate (CA)/silica (SiO₂)/MOF mixed matrix membranes was investigated with two types of MOFs, UiO-66 which synthesis and characterization has been previously reported, and UiO-66-NH₂. The UiO-66-NH₂ MOFs were synthesized and characterized by infrared spectroscopy, X-ray diffraction, nitrogen adsorption–desorption equilibrium at −196 °C, and thermogravimetry analysis. Both mixed matrix membranes were synthesized by coupling the phase inversion technique with the sol–gel method and with casting solutions incorporating the MOF dispersions. The two membrane types of MOFs were characterized in terms of hydraulic permeability, molecular weight cut-off, and rejection coefficients to pCS and bovine serum albumin (BSA). The mixed matrix membranes CA/SiO₂/UiO-66-NH₂ exhibited lower permeability and molecular weight cut-off when compared to the CA/SiO₂/UiO-66 ones. In permeation tests simulating a hemodialysis session with a feed solution of 100 ppm pCS and 35 g/L BSA, it is shown the improved performance of MOFs membranes as the rejection coefficients of free pCS is 0.2% for the CA22/SiO₂/UiO-66 membrane with 1.5% of MOF and 2.6% for the CA22/SiO₂/UiO-66-NH₂ membrane with 2% of MOF. The capacity of these MOF membranes in removing pCS bound to BSA was addressed through the development of a new methodology to quantify the pCS free and bound to BSA. The CA22/SiO₂/UiO-66 membrane with 1.5% of MOF has a removal capacity of 99.8% and the CA22/SiO₂/UiO-66-NH₂ membrane with 2% of MOF 95.9%. Based on these results, it is concluded that the mixed matrix membranes CA22/SiO₂/UiO-66 and CA22/SiO₂/UiO-66-NH₂ are promising candidates for PBUTs removal in hemodialysis. Full article

The development of efficient and sustainable photothermal catalytic systems is pivotal for modern organic transformations. Herein, we report the rational design and solvothermal synthesis of NH₂-MIL-101(Fe) metal–organic frameworks (NM-101) integrated with carbon nanotubes (CNTs) for the photothermal reduction in nitronaphthalene. The optimized NM-101/75C composites exhibit exceptional catalytic activity and high selectivity under NIR light irradiation, delivering a high yield of 84.4% within 1 h, which significantly outperforms its individual components. Systematic control experiments and detailed spectroscopic investigations reveal a powerful synergistic effect at the MOF-CNT interface, where the CNTs play a dual role in augmenting light harvesting and facilitating charge carrier separation. Furthermore, the high photothermal conversion efficiency of the composite enables rapid reaction kinetics. This work provides a robust and scalable strategy for constructing high-performance photothermal catalysts, offering critical insights into the interfacial engineering of MOF-based materials for industrial chemical manufacturing. Full article

Emerging viral diseases continue to pose major challenges to global health, creating demand for materials that can support pathogen control, diagnosis, and therapy. Owing to their tunable structures and versatile biointerfaces, metal–organic frameworks (MOFs) have attracted increasing attention in anti-pathogen applications. While previous studies have often focused on individual functions such as catalysis, biosensing, or drug delivery, a broader perspective on the functional development of MOF-based systems remains limited. In this Review, we summarize recent advances in MOF-enabled pathogen inactivation, diagnostic biosensing, host-directed intervention, and virus-inspired therapeutic platforms. Emerging opportunities in antiviral drug discovery and artificial intelligence-assisted materials design are also discussed. In addition, key challenges associated with structural stability, biosafety, scalable fabrication, and clinical translation are highlighted. This Review provides an overview of current progress and outlines perspectives for the future development of MOF-based anti-pathogen technologies. Full article