Search Results (3,523)

Counteracting neurodegenerative diseases (NDs) presents a multifaceted challenge in the aging societies of Western countries. Each year, millions of people worldwide are affected by such ailments as Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), multiple sclerosis (MS), spinal cord injury, ischemic stroke, motor neuron disease, spinal muscular atrophy, spinocerebellar ataxia, and amyotrophic lateral sclerosis (ALS). Advancements in modern biomaterial technologies present substantial opportunities for the field of regenerative medicine. Nevertheless, limitations arise from the requirement that biomaterial design be tailored to the specific biological parameters of the target cell types with which they are intended to interact. Such an opportunity creates nanomaterials involving nanoparticles. The surface chemistry of nanoparticles, especially when functionalized with bioactive agents, enhances biocompatibility and facilitates interactions with nervous cells. Herein, we review contemporary strategies in the application of biomaterials for nerve regeneration, with particular emphasis on nanomaterials and biocompatible polyelectrolyte layers, which the authors identify as having the most significant potential to drive transformative advances in regenerative medicine in the near future. Full article

Among the main man-made water pollutants that pose a danger to the environment are oil products, heavy metals, and radionuclides, as well as micro- and nanoplastics. To purify such waters, it is necessary to use advanced methods, with sorption being one of them. The aim of this work is to develop a nano-functionalized composite, comprising magnetically responsive, thermally expanded graphite (TEG) and the natural clay bentonite, and to assess its ability to purify man-made contaminated waters. Throughout the course of the research, the methods of scanning electron microscopy, optical microscopy, dynamic light scattering, radiometry, and atomic absorption spectrophotometry were used. The use of the TEG–bentonite composite for the purification of the model water, simulating radioactively contaminated nuclear power plant (NPP) effluent, reduced the content of organic substances by 10–15 times, and the degree of extraction of cesium, strontium, cobalt, and manganese was between 81.4% and 98.8%. The use of the TEG–bentonite composite for the purification of real radioactively contaminated water obtained from the object “Shelter” (“Ukryttya” in Ukrainian), in the Chernobyl Exclusion Zone, Ukraine, with high activity, containing organic substances, including micro- and nanoplastics, reduced the radioactivity by three orders of magnitude. The use of cesium-selective sorbents for additional purification of the filtrate allowed for further decontamination of radioactively contaminated water with an efficiency of 99.99%. Full article

Deforestation and wildfires drastically impact vegetation cover, consequently affecting water dynamics. These hazards alter the different components of the water cycle, including evapotranspiration, runoff, infiltration, and groundwater recharge. Overall, runoff increases while infiltration and groundwater recharge decrease. Furthermore, these hazards significantly alter the chemistry of both surface water and groundwater. The main changes to water quality relate to turbidity, bacterial load, mineralization and nutrients. Forest fires can also release contaminants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Other contaminants can be introduced by products used in firefighting, such as retardants and perfluoroalkyl substances (PFAS). This paper reviews the impact of deforestation and wildfires on water resources, especially with a view to their use as raw water for drinking water production. The paper identifies the magnitude of the changes induced in water quantity and quality. Even if the results are climate- and site-specific, they provide an indication of the possible magnitude of these impacts. Finally, the various changes brought about by these hazards are ranked according to their potential impact on drinking water production. Full article

With the rapid increase in the synthesis and application of graphene oxide (GO), questions have emerged about its inadvertent entry into aquatic habitats and the ecological consequences associated with such exposure While several studies have addressed the acute effects of GO, knowledge on its chronic impacts across multiple trophic levels remains limited. In this study, we assessed the chronic toxicity of a well-characterized GO product using model organisms representing three trophic levels: the bioluminescent marine bacterium Aliivibrio fischeri, unicellular green algae (Chlamydomonas reinhardtii, Chlorella vulgaris, Desmodesmus subspicatus), the cyanobacterium Synechococcus elongatus, and the freshwater cladoceran Daphnia magna. Endpoints included bioluminescence inhibition in bacteria, growth inhibition in photosynthetic primary producers, and reproduction and refined physiological parameters (heart rate, feeding activity) in D. magna. Our results demonstrated clear concentration-dependent chronic effects of GO, with A. fischeri, the applied photosynthetic primary producers and D. magna exhibiting significant inhibition of bioluminescence, growth, delayed onset of reproduction, and reduced fitness parameters, respectively. Based on the collected data, a comprehensive ecotoxicological risk assessment was carried out, revealing that pristine GO may pose negligible hazard to aquatic ecosystems under environmentally relevant exposure scenarios. The outcomes clearly demonstrate the relevance of incorporating chronic and multi-trophic effects when evaluating the ecological risks of emerging nanomaterials such as GO. Full article

Growing interest in sustainable hydrogen production has brought renewed attention to photoelectrochemical (PEC) water splitting as a promising route for direct solar-to-chemical energy conversion. This study explores how integrating hematite (α-Fe₂O₃) and cupric oxide (CuO) photoelectrodes with a series of nickel-based co-catalysts can improve photoelectrochemical activity. Photoanodic (NiO_x, NiFeO_x, NiWO₄) and photocathodic (Ni, NiCu, NiMo) co-catalysts were synthesized via co-precipitation and mechanochemical methods and characterized through X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Transmission Electron Microscopy–Energy Dispersive X-ray Spectroscopy (TEM-EDX), Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) gas-adsorption analyses to clarify their crystallographic, morphological, and compositional properties, as well as their surface chemistry and textural properties (surface area and porosity). Electrochemical tests under 1 SUN illumination showed that NiO_x significantly improves the photocurrent of hematite photoanodes. Among the cathodic co-catalysts, NiMo demonstrated the best performance when combined with CuO photocathodes. For both photoelectrodes, an optimal co-catalyst loading was identified, beyond which performance declined due to potential charge transfer limitations and light attenuation. These findings highlight the critical role of co-catalyst composition and loading in optimizing the efficiency of PEC systems based on earth-abundant materials, offering a pathway toward scalable and cost-effective hydrogen production. Full article

Silver nanoparticles (AgNPs) have attracted significant attention in recent years in diverse fields owing to their broad mechanisms of action. In particular, the wound healing process has become one of the main fields where the therapeutic potential of AgNPs is highlighted. AgNPs can be used as monotherapy or incorporated into composite structures in various formulations such as nanogels, hydrogels, powders, ointments, and sprays, for the treatment of a wide range of wound types including burns, excisional and incisional wounds, bone defects, surgical wounds, and diabetic ulcers. This widespread use is attributed to the strong antibacterial, anti-inflammatory, antioxidant, and cell proliferation-promoting biological properties of AgNPs. Moreover, AgNPs exhibit synergistic effects when combined with conventional antibiotics, enhancing their efficiency against resistant bacterial strains or even restoring the lost antibacterial activity. These biological properties enable AgNPs to reduce infection risk while simultaneously promoting high-quality healing by accelerating tissue regeneration. The therapeutic effectiveness of AgNPs is influenced by their physicochemical properties, including particle size, shape, and surface chemistry. In particular, synthesis methods play a significant role in determining both the biological activity and the safety profile of AgNPs. Among various methods, green synthesis approaches stand out for enabling the production of environmentally friendly, non-toxic, and highly biocompatible AgNPs. In this review, the mechanisms of action of AgNPs in wound healing are examined in detail, and recent scientific developments in this field are evaluated based on current in vitro, in vivo, and clinical studies. Full article

The growing demand for sustainable and efficient synthetic methodologies has brought nanocatalysis to the forefront of modern organic chemistry, particularly in the construction of heterocyclic compounds through multicomponent reactions (MCRs). Among various nanocatalysts, calcium oxide nanoparticles (CaO NPs) have gained significant attention because of their strong basicity, thermal stability, low toxicity, and cost-effectiveness. This review provides a comprehensive account of the recent strategies using CaO NPs as heterogeneous catalysts for the green synthesis of nitrogen- and oxygen-containing heterocycles through MCRs. Key reactions such as Biginelli, Hantzsch, and pyran annulations are discussed in detail, with emphasis on atom economy, reaction conditions, product yields, and catalyst reusability. In many instances, CaO NPs have enabled solvent-free or aqueous protocols with high efficiency and reduced reaction times, often under mild conditions. Mechanistic aspects are analyzed to highlight the catalytic role of surface basic sites in facilitating condensation and cyclization steps. The performance of CaO NPs is also compared with other oxide nanocatalysts, showcasing their benefits from green metrics evaluation like E-factor and turnover frequency. Despite significant progress, challenges remain in areas such as asymmetric catalysis, industrial scalability, and catalytic stability under continuous use. To address these gaps, future directions involving doped CaO nanomaterials, hybrid composites, and mechanochemical approaches are proposed. This review aims to provide a focused and critical perspective on CaO NP-catalyzed MCRs, offering insights that may guide further innovations in sustainable heterocyclic synthesis. Full article

This study explores the use of mid-infrared (MIR) free-electron laser (FEL) irradiation as a tool for tailoring the surface properties of electrochemically synthesized TiO₂—graphene quantum dots (QDs). The QDs, prepared in colloidal form via a cost-effective electrochemical method in a KCl—citric acid medium, were exposed to MIR wavelengths (5.76, 8.02, and 9.10 µm) at the Kyoto University FEL facility. Post-irradiation measurements revealed a pronounced inversion of zeta potential by 40–50 mV and approximately 10% reduction in hydrodynamic size, indicating double-layer contraction and ionic redistribution at the QD—solvent interface. Photoluminescence spectra showed enhanced emission for GQDs and TiO₂/GQD composites, while Tauc analysis revealed modest bandgap blue shifts (0.04–0.08 eV), both consistent with trap-state passivation and sharper band edges. TEM confirmed intact crystalline structures, verifying that FEL-induced modifications were confined to surface chemistry rather than bulk lattice damage. Taken together, these results demonstrate that MIR FEL irradiation provides a resonance-driven, non-contact method to reorganize ions, suppress defect states, and improve the optoelectronic quality of QDs. This approach offers a scalable post-synthetic pathway for enhancing electron transport layers in perovskite solar cells and highlights the broader potential of photonic infrastructure for advanced nanomaterial processing and interface engineering in optoelectronic and energy applications. Full article

Developing high-activity and high-durability Pd-based electrocatalysts is an important strategy to promote their commercial application. Herein, a smaller particle size and ultrathin sheet-like PdCu alloy metallene (PdCuene) were successfully prepared by using a one-pot wet chemistry method for FAOR. Experimental measurements indicated that the introduction Cu into Pd lattice induces a significant compressive strain effect through lattice mismatch between Pd and Cu, and the strain effect optimizes the electronic structure of Pd, as well as the high electrochemical surface area, increased exposure of active sites, and appropriate lattice strain have been demonstrated as factors that influence the enhancement of intrinsic activity and the acceleration of kinetics, thereby improving FAOR performance. Moreover, the stronger lattice strain of 0.85% would facilitate surface adsorption and dissociation of formic acid. Specifically, the optimized PdCuene exhibits enhanced mass activity and specific activity with current densities of 2.31 A mg_Pd⁻¹ and 4.09 mA cm⁻², respectively, which transcend the activities of Pd metallene (1.44 A mg_Pd⁻¹ and 2.73 mA cm⁻²) and commercial Pd/C (0.6 A mg_Pd⁻¹ and 1.53 mA cm⁻²). Meanwhile, PdCuene displayed obvious enhanced durability. The work provides an approach to modulate the lattice strain engineering, which represents a highly promising strategy for designing efficient FAOR electrocatalysts. Full article

Microplastics entering the gastrointestinal environment rapidly acquire protein coronas that alter their surface chemistry and analytical detectability. We investigated the physicochemical interactions between fluorescently labeled bovine serum albumin (BSA) and polyethylene terephthalate (PET) microplastics during simulated intestinal exposure and evaluated the stability of the resulting hard corona. Using fluorescence tracking, SDS-PAGE, and FTIR spectroscopy, we showed that BSA forms a persistent corona that resists oxidative-only treatments. Only a combination of oxidation with an alkaline (KOH) or surfactant step (SDS) effectively removed the corona. None of the protocols applied affected polymer integrity. Residual protein in less effective protocols did not show changes on PET spectra in ATR FTIR. To validate the protocol under physiologically relevant complexity, we extended it to PET incubated with single digestive enzymes. FTIR spectra confirmed the removal of protein-specific signals in both systems, with no degradation of PET ester or aromatic functional groups nor signals of protein–polymer interactions. Our results highlight the robustness of protein–PET interactions in biological conditions and provide a variety of protocols for protein corona removal, suitable for diverse applications of microplastic analysis and toxicological studies. Full article

Alzheimer’s disease (AD) requires early and accurate identification of affected brain regions, which can be achieved through the detection of specific biomarkers to enable timely intervention. Carbon nanomaterials (CNMs), including graphene derivatives, carbon nanotubes, graphitic carbon nitride, carbon black, fullerenes, and carbon dots, offer high conductivity, large electroactive surface area, and versatile surface chemistry that enhance biosensor performance. While such properties benefit a wide range of transduction principles (e.g., electrochemical, optical, and plasmonic), this review focuses on their role in electrochemical biosensors. This review summarizes CNM-based electrochemical platforms reported from 2020 to mid-2025, employing aptamers, antibodies, and molecularly imprinted polymers for AD biomarker detection. Covered topics include fabrication strategies, transduction formats, analytical performance in complex matrices, and validation. Reported devices achieve limits of detection from the femtomolar to picogram per milliliter range, with linear ranges typically spanning 2–3 orders of magnitude (e.g., from femtomolar to picomolar, or from picogram to nanogram per milliliter levels). They exhibit high selectivity against common interferents such as BSA, glucose, uric acid, ascorbic acid, dopamine, and non-target peptides, along with growing capabilities for multiplexing and portable operation. Remaining challenges include complex fabrication, limited long-term stability and reproducibility data, scarce clinical cohort testing, and sustainability issues. Opportunities for scalable production and integration into point-of-care workflows are outlined. Full article

The severe ozone depletion over the Southern polar region, known as the “ozone hole,” is a stark example of global ozone depletion caused by human-made chemicals. This has implications for climate change and increased harmful surface solar UV. Several Chemistry–Climate models (CCMs) tend to underestimate total column ozone (TCO) against satellite measurements over the Southern polar region. This underestimation can reach up to 50% in monthly mean zonally averaged biases during cold seasons. The most significant discrepancies were found in the CCM SOlar Climate Ozone Links version 3 (SOCOLv3). We use SOCOLv3 to study the sensitivity of Antarctic TCO to three key factors: (1) stratospheric heterogeneous reaction efficiency, (2) meridional flux intensity into polar regions from sub-grid scale mixing, and (3) photodissociation rate calculation accuracy. We compared the model results with satellite data from Infrared Fourier Spectrometer-2 (IKFS-2), Microwave Limb Sounder (MLS), and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). The most effective processes for improving polar ozone simulation are photolysis and horizontal mixing. Increasing horizontal mixing improves the simulated TCO seasonal cycle but negatively impacts CH₄ and N₂O distributions. Using the Cloud-J v.8.0 photolysis module has improved photolysis rate calculations and the seasonal ozone cycle representation over the Southern polar region. This paper outlines how different processes impact chemistry–climate model performance in the southern polar stratosphere, with potential implications for future advancements. Full article

In 2023, studies were carried out on the aquatic environment of the forest lake Łętowskie. The studies covered the horizontal and vertical planes and seasonal dynamics. Lake Łętowskie is a lake with an area of 402 ha, which distinguishes it from other lakes in Pomerania due to its large area. In three quarters of the lake shore border forests, changes in surface and volume have been observed in the lakes over the last century, which has affected the chemistry of the water. The aims of this study were to determine the dependencies between the concentration of biogenic substances in the near-bottom layer and subsurface water and analyze the dependencies between chemical parameters in the water of the mid-forest lake Łętowskie. In the water samples obtained, including the surface layer (SW) and the near-bottom layer (NBL), the concentrations of N-NO₃, N-NO₂, N-NH₄, N-tot, N-org, P-PO₄, P-tot, P-org, and O₂, electrolytic conductivity, pH, Ca, and Mg were determined. Statistical analyses were carried out, including tests and multidimensional PCA and cluster analysis. A significant effect of forests on the chemical composition of lake water was observed. The conducted studies of Łętowskie Lake indicate that the NBL experiences seasonal dynamics, where phosphorus and nitrogen compounds are transformed, which causes trophic changes in the lake. Based on multidimensional cluster analysis, differences between the SW and the NBL were shown. In Łętowskie Lake, the level of biogenic substances in the water is significantly influenced by processes occurring inside the lake as a result of the exchange of matter between the NBL and bottom sediments. This exchange in shallower areas of the lake is influenced by winds, especially in exposed locations: this was observed for P-tot, P-PO₄, P-org, Ca, N-NO₃ and N-NH₄, N-tot, and N-org. The conducted studies are important for supporting the protection of the Landscape Area “Łętowskie Lake and the vicinity of Kępice” to preserve the existing values of the natural environment and maintain the ecological balance of natural systems. Current scientific publications on the hydrochemical data of Łętowskie Lake are currently lacking, and the available data needs to be updated. Full article

Surface coating materials have many applications in various sectors, such as aerospace, medical technology, packaging, and construction, due to their unique properties, including self-healing, corrosion resistance, and protection from external factors. Their use not only enhances the durability and lifespan of surfaces but also their functionality and esthetic value. These coatings can be effective barriers against moisture, oxygen, chemicals, and the growth of microorganisms, which makes them indispensable in industries where reliability and safety are paramount. In the aerospace sector, they provide protection at extreme temperatures and limit component wear. Special coatings in biomedicine improve implant compatibility and prevent bacterial adhesion. In packaging, they extend the shelf life of products, while in construction they prevent the degradation of structural elements. This review article examines the major categories of these materials, as well as their advantages and limitations, and demonstrates a comparative evaluation of their use in certain applications. Full article

The aim of present study is to deposit protective coatings with various surface chemical states on AZ91D Mg alloy. Hydrothermal bioactive ceramic coatings are performed with a surface modification by the chemical bonding of self-assembled monolayers (SAM). The electrochemical corrosion behaviors of various surface-coated AZ91D alloy within DMEM cell culture medium related to their surface chemical states are evaluated through microstructure observations, XPS surface chemical bonding analysis, static contact angles measurements, potentiodynamic polarization curves, and immersion tests. XRD and high resolution XPS of F 1s analysis results show that the hydrothermal FHA coating with a phase composition of Ca₁₀(PO₄)₆(OH)F can be effectively and uniformly deposited on the AZ91D alloy. FHA-coated AZ91D displays better anti-corrosion performances and lower degradation rates than those of uncoated AZ91D alloy in the DMEM solution. Through the high resolution XPS analysis of O 1s and P 2p spectra, it is demonstrated that 1-butylphosphonic acid (BP), 1 octylphosphonic acid (OP), and dodecylphosphonic acid (DP) molecules can be effectively bonded on the FHA surface by a covalent bond to form SAM. BP/OP/DP-SAM specimens display increased static contact angles to show a hydrophobic surface. It demonstrates that the SAM surface treatment can further enhance the corrosion resistance of FHA-coated AZ91D in the DMEM solution. After 2–16 days in vitro immersion tests in the DMEM, the surface SAM-bonded hydrophobic BP/OP/DP-SAM layers can effectively inhibit and reduce the penetration of DMEM into FHA coating. Long alkyl chains of the dodecylphosphonic acid (DP) SAM represents superior enhancing effects on the reduction of corrosion properties and weight loss. Full article