Search Results (465)

Micro(nano)plastics (MNPs), as a globally emerging environmental pollutant, are now ubiquitous in natural environments and can continuously enter the human body through ingestion, inhalation, and dermal contact. This widespread exposure has raised significant concerns regarding the potential health risks posed by MNPs. Although epidemiological studies are still in the early stages, accumulating in vitro cellular experiments have provided key evidence suggesting that nano- to micro-sized plastic particles can cross physiological barriers in the human body. These particles enter cells via endocytosis or direct penetration through the cell membrane, triggering toxic effects such as oxidative stress, immune responses, mitochondrial dysfunction, and DNA damage, which can potentially lead to cell apoptosis. These findings highlight that the direct interaction between MNPs and human cells could be a core mechanism underlying their potential health hazards. This review systematically summarizes the toxic effects of MNPs exposure on various human cell types, exploring the underlying molecular mechanisms and providing insights for future research into the toxicological impacts of MNPs and their implications for human health risk assessment. Full article

Plastic pollution represents a significant emerging environmental problem. Micro-sized particles of synthetic polymers—microplastics (MPs)—have been identified in all parts of marine ecosystems. In the marine environment, organisms are exposed to MPs, which undergo a constant process of physicochemical and biological degradation. Utilization of UV irradiation as the optimal exposure factor in the simulation of fundamental natural conditions is a widely accepted approach. This enables the study of the harmful effects of such particles when interacting with aquatic organisms. This study aimed to investigate the effect of pristine and photoaging primary polystyrene microspheres (µPS) at three concentrations on the viability and DNA integrity of the sperm of the sand dollars Scaphechinus mirabilis. The results of the investigation demonstrated that IR spectroscopy revealed structural changes in polystyrene, confirming the oxidative degradation of the polymer under UV irradiation. The study demonstrated that artificially aged µPS exhibited a more pronounced effect than pristine particles, as evidenced by reduced sperm viability and increased DNA damage. Thus, the resazurin test showed that after exposure to UV-irradiated µPS, sperm viability decreased to 83–85% at concentrations of 10 and 100 particles and to 70% at a concentration of 1000. In addition, the Comet assay showed that the particles increased the percentage of DNA in the tail from 20% to 30% in a dose-dependent manner. The findings substantiate and augment the existing body of experimental data of the toxicity of aged plastic fragments, thereby underscoring the need for further study into the toxicity of aged MPs on marine invertebrates. Full article

Overcoming the strength–ductility trade-off in conventional aluminum matrix composites (AMCs) remains a significant challenge. This study employs dual-scale hybrid reinforcement particles comprising micron-sized Cu and nano-sized Ti, alongside bimodal micro-sized pure Al powders as matrix fillers. The AMCs were fabricated through ball milling (BM) combined with multi-pass friction stir processing (FSP). The homogenously distributed hybrid reinforcement particles generate an integrated composite region consisting of both coarse-grained (CG) and fine-grained (FG) structures, demonstrating enhanced material characteristics. The interwoven network of coarse- and fine-crystalline domains constructs a heterogeneous architecture that enables simultaneous improvement in both strength and ductility properties. The micron-Cu acts as a skeletal support within the matrix, enhancing load transfer efficiency and effectively hindering dislocation motion. The nano-Ti and in situ intermetallics facilitate grain refinement via the pinning effect and promote heterogeneous nucleation, which contributes to stress dispersion and dislocation obstruction. The addition of dual-scale micron-sized pure Al powder particles promotes the formation of the heterogeneous architecture, which enhances the balancing of strength and ductility in the composite. Following compositing (Al₁₀-5Cu-10Ti-10Al₂₀), the alloy exhibits an ultimate tensile strength (UST) of 267 MPa, a hardness of 98 HV, and an elongation of 16.7%, representing increases of 193.4%, 226.7%, and 9.9%, respectively, relative to the base metal. Full article

The experimental study has been carried out using advanced computer vision methods in order to visualize the moment of excitation and further propagation of a non stationary isotropic domain in a hybrid aligned nematic (HAN) microsized volume under the effect of a laser beam focused on a bounding liquid crystal surface. It has been shown that, when the laser power exceeds a certain threshold value, in bulk of the HAN microvolume, an isotropic circular domain is formed. We also observed a structure of alternating concentric rings around the isotropic circular region, which increases with distance from the center of the isotropic domain. The formation of a sequence of rings in a polarizing microscopic image indicates the formation of a complex topology of the director field in the HAN cell under study. The following evolution of the texture can be represented by two modes. Firstly, the “fast” heating mode, which is responsible for the formation and explosive expansion of an isotropic zone in bulk of the HAN microvolume with characteristic time ${\tau }_1$ due to a laser spot heating on the upper indium tin oxide (ITO) layer. Secondly, the “slow” heating mode, when an isotropic zone and concentric rings slowly expand with characteristic time ${\tau }_2$ mainly due to the finite thermoconductivity of ITO layer. When the laser power significantly exceeds the threshold value, damped oscillations of the isotropic domain are observed. We also introduced the metrics that allows quantitatively estimate the behavior of texture observed. The results obtained form an experimental basis for further investigation of thermomechanical force appearing in the LC system with coupled gradients of temperature and director fields. Full article

This study numerically and experimentally investigated the maximum heat transfer rate of the evaporator in loop heat pipes (LHPs) using a pore network simulation that considers the vapor–liquid interface within the evaporator wick under high heat flux conditions. The numerical model was validated with previous results. Based on the validated model, the boundary conditions were modified to consider high heat flux conditions. Also, a porous medium approach was applied to predict the working fluid flow in multiscale wicks, which were fabricated by sintering micro-sized SAC305 particles onto conventional screen mesh wicks. The effective pore radius and permeability of multiscale wicks were experimentally measured using the rate-of-rise method. Using the modified numerical model and experimental results, a parametric study was conducted on sintered weight fraction (SWF), fin ratio, and wick thickness to evaluate their effects on the maximum heat transfer rate of the LHP evaporator. As a result, the maximum heat transfer rate increased with higher SWF and thicker wicks due to improved capillary performance and greater vapor growth space, while a higher fin ratio reduced the maximum heat transfer rate by decreasing the vapor groove area. Under optimal conditions, a maximum heat flux of 800 W/cm² was achieved. Full article

While immunophilins are well-recognized therapeutic targets, several members of this family of peptidyl-proline isomerases (PPIases) have yet to be subjected to ligand discovery efforts. In this study, we demonstrate a cost-effective means to identify ligands to the insufficiently investigated two-domain PPIase human Cyclophilin40 (Cyp40). Central to this effort was the use of beads, wherein a confocal nanoscanning (CONA) approach was used to rapidly probe candidates. Here, we describe how one can adapt the physical nature of microsized beads as a means to strategically reduce cost and ultimately make the discovery of small molecule hit and lead compounds more accessible to everyone irrespective of financial status (democratization). Full article

Microplastics, synthetic polymer particles measuring less than 5 mm, have become a widespread environmental pollutant, raising concerns over their possible effects on human health. Growing evidence links MPs to vascular aging and cardiovascular disease beyond their ecological toxicity. Upon inhalation, ingestion, or skin contact, microplastics can traverse biological barriers, circulate systemically, and accumulate in vascular tissues. Experimental investigations indicate that MPs, especially polystyrene and polyethylene in nano- and micro-sized forms, induce oxidative stress, mitochondrial dysfunction, and chronic inflammation. These disruptions activate redox-sensitive signaling pathways, such as NF-κB and NLRP3 inflammasome, causing endothelial dysfunction, vascular smooth muscle modulation, and foam cell production, indicating early vascular aging. Animal models and in vitro studies have consistently shown endothelial activation, increased cytokine production, and changes in vascular tone after exposure to MPs. Initial human research has detected microplastics in blood, thrombi, and atherosclerotic plaques, which correlate with negative cardiovascular outcomes and systemic inflammation. Notably, recent research suggests that the gut microbiota and antioxidant systems may play a role in adaptive reactions, although these processes are still not fully understood. MP-induced vascular toxicity is covered in this interdisciplinary review, highlighting molecular pathways, experimental data, and translational gaps. Full article

The search for a simple, scalable, and eco-friendly method for synthesizing micro-sized photocatalysts is an urgent task. Plasma technologies are highly effective and have wide possibilities for targeted synthesis of novel materials. The mass-average temperature of plasma treatment is higher than the stability temperature of anatase and brookite, the most photoactive polymorphs of titanium dioxide. In this work, by optimizing the plasma treatment conditions and selecting source materials, a method for synthesizing micro-sized photocatalyst based on heterocomposite TiO₂/ZnO particles with high anatase content is proposed. The synthesis method involves treating a powder mixture of titanium and zinc by low-temperature argon plasma under atmospheric conditions. The relationship between the structural-phase composition, morphology, and photocatalytic properties of the microparticles was investigated. A model for the synthesis of composite microparticles containing anatase, rutile, and heterostructural contact with zinc oxide is proposed. The photocatalytic degradation of methylene blue and metronidazole was studied to evaluate both sensitized and true photocatalytic processes. The metronidazole degradation confirmed the intrinsic photocatalytic activity of the synthesized composites. Additionally, the features of photocatalysis under UV and solar irradiation were studied, and a photocatalysis mechanism is proposed. The synthesized micro-sized heterocomposite photocatalyst based on TiO₂/ZnO contained anatase (36%), rutile (60), and brookite (4%) and showed a photocatalytic activity during the methylene blue degradation process under UV irradiation (high-pressure mercury lamp, 250 W): 99% in 30 min. Full article

Implantation studies are extremely important to solve reproductive problems since about 60% of abortions occur around this period. The 3D in vitro models emerge as closest to the in vivo structures and processes. Here, we constructed trophoblast Sw71-spheroids as implanting human blastocyst–like surrogates (BLS). The model is well-characterized, standardized, validated tool to study extravillous trophoblast (EVT) invasion/migration during implantation. A limitation is that it is a short-living 3D-culture that must be generated de novo. This study aimed to create and embed Sw71-spheroids in paraffin for permanent histological preparations. The main challenges were the micro-size and the preservation of the intact structure. The standardly generated compact and stable Sw71-spheroids were intact, with blastocyst-like morphology. Histological analysis showed preserved cell morphology, shape, and intact periphery of the embedded Sw71-spheroids. These were usable for immunohistochemistry(IHC) and expressed common EVT markers: EpCAM, HLA-C and and HLA-G. Our protocol for spheroid paraffin embedding is suitable for simultaneous histological analyses of several Sw71-spheroids. It might be further optimized to embed migrating/invading Sw71-BLS as snapshots of trophoblast implantation steps in permanent histological preparations for in depth IHC studies. Full article

Plastic waste accumulation is one of the most pressing environmental challenges of the 21st century, owing to the widespread use of synthetic polymers and the limitations of conventional recycling methods. Among available strategies, chemical upcycling via depolymerization has emerged as a promising circular approach that converts plastic waste back into valuable monomers and chemical feedstocks. This article provides an in-depth narrative review of recent progress in the upcycling of major plastic types such as PET, PU, PS, and engineering plastics through thermal, chemical, catalytic, biological, and mechanochemical depolymerization methods. Each method is critically assessed in terms of efficiency, scalability, energy input, and environmental impact. Special attention is given to innovative catalyst systems, such as microsized MgO/SiO₂ and Co/CaO composites, and emerging enzymatic systems like engineered PETases and whole-cell biocatalysts that enable low-temperature, selective depolymerization. Furthermore, the conversion pathways of depolymerized products into high-purity monomers such as BHET, TPA, vanillin, and bisphenols are discussed with supporting case studies. The review also examines life cycle assessment (LCA) data, techno-economic analyses, and policy frameworks supporting the adoption of depolymerization-based recycling systems. Collectively, this work outlines the technical viability and sustainability benefits of depolymerization as a core pillar of plastic circularity and monomer recovery, offering a path forward for high-value material recirculation and waste minimization. Full article

Sulfion oxidation reaction (SOR) has great potential in replacing oxygen evolution reaction (OER) and boosting highly efficient hydrogen evolution. The development of highly active and stable SOR electrocatalysts is crucial for assisting hydrogen production with low energy consumption. In this work, multiphase NiCoFe-based layered double hydroxide (namely NiCoFe-LDH) has been synthesized via a facile seed-assisted heterogeneous nucleation method. Benefiting from its unique microsized hydrangea-like structure and synergistic active phases, the catalyst delivers substantial catalytic interfaces and reactive centers for SOR. Consequently, NiCoFe-LDH electrode achieves a remarkably low potential of 0.381 V at 10 mA cm⁻² in 1 M KOH + 0.1 M Na₂S, representing a significant reduction of 0.98 V compared to conventional OER. Notably, under harsh industrial conditions (6 M KOH + 0.1 M Na₂S, 80 °C), the electrolysis system based on NiCoFe-LDH||NF pair exhibits a cell potential of only 0.71 V at 100 mA cm⁻², which shows a greater decreasing amplitude of 1.05 V compared with that of traditional OER/HER systems. Meanwhile, the NiCoFe-LDH||NF couple could maintain operational stability for 100 h without obvious potential fluctuation, as well as possessing a lower energy consumption of 1.42 kWh m⁻³ H₂. Multiphase eletrocatalysis for SOR could indeed produce hydrogen with low-energy consumption. Full article

The co-occurrence of the synthesis of a functionalized magnetic nano iron oxides–biochar composite (MFe@BC) via impregnation–thermal pyrolysis and its use to remove micro-sized poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microplastics from simulated wastewater was demonstrated in this study. The results showed that PHBV removal efficiency correlated positively with MFe@BC dosage, achieving an adsorption capacity of 13.14 mg/g and a removal efficiency of 98.53% at an optimal dosage of 1.5 g/L. Adsorption kinetics fit a pseudo-second-order model (R² = 0.9999), and the isotherm followed the Langmuir model (R² = 0.8440), yielding a theoretical maximum capacity of 31.96 mg/g. Characterization indicated chemisorption-driven monolayer adsorption via surface complexation and hydrogen bonding. Magnetic nano-iron transfer from MFe@BC to the PHBV surface imparted magnetic properties to PHBV, enabling synergistic adsorption and magnetic separation. Removal efficiency remained above 95% across pH 4–9 and COD 0–500 mg/L. Regeneration experiments indicated that the MFe@BC showed robust reusability, maintaining >92% PHBV removal efficiency after four adsorption–regeneration cycles. The results of this study may provide a feasible pathway for PHBV microplastic removal from secondary effluent, indicating that MFe@BC prepared in this study can be used for the removal of PHBV microplastics in a wide range of water bodies. Full article

Understanding the dynamics of phytoplankton size classes (PSCs), highly sensitive to environmental conditions in marine ecosystems, is crucial for comprehending variations in primary production and biogeochemical processes. Over the past decades, the littoral seas of Korea have undergone significant environmental shifts, yet long-term studies on PSC distribution remain limited. Employing a regionally developed deep neural network model and 20 years (2003–2022) of satellite ocean color data, we assessed spatiotemporal variability in dominant PSCs in the Yellow Sea (YS), South Sea of Korea (SS), and East/Japan Sea (EJS). Micro-size phytoplankton dominated turbid nearshore waters of the YS and western SS year-round, while nano-size phytoplankton were seasonally prevalent in the central YS and EJS. Pico-size phytoplankton exhibited strong summer dominance under warm, stratified, nutrient-depleted conditions, showing a sustained long-term expansion across all regions, particularly in the southwestern EJS. This expansion was closely linked to rising sea surface temperatures and changes in nutrient stoichiometry. The increasing dominance of smaller phytoplankton may reduce primary production, alter food web structure, and ultimately diminish fishery productivity. These findings provide new insight into climate-driven ecological shifts in marginal seas and underscore the need for integrated long-term monitoring to anticipate future ecosystem responses in a rapidly warming ocean. Full article

The use of Li-ion batteries is drastically increasing, especially due to the growing sales of electric vehicles. Simultaneously, there is a shift towards exchanging the traditional Co- and Ni-rich electrode materials with more sustainable alternatives such as LiFePO₄. This transition challenges conventional recycling practices, which typically rely on shredding batteries into a substance known as black mass, which is subsequently processed via hydrometallurgical or pyrometallurgical methods to extract valuable elements. These routes may not be economically viable for future sustainable chemistries with lower contents of high-value metal. Hence, new methods for processing the black mass, allowing, e.g., for physical separation and direct recycling, are direly needed. Such developments require that the black mass is thoroughly understood. In this study, we thoroughly characterize a commercially produced Graphite/LFP black mass sample from real battery waste using a suite of analytical techniques. Our findings reveal detailed chemical, morphological, and structural insights and show that the components in the black mass have different micro-size profiles, which may enable simple size separation. Unfortunately, our analysis also reveals that the employed processing of battery waste into black mass leads to the formation of an unknown Fe-containing compound, which may hamper direct recycling routes. Full article

Based on the field data of laser interference devices obtained on the shelf of the Sea of Japan, the interaction of internal sea waves with the bottom and the transfer of energy from the sea wave to the seismic acoustic wave were studied. It has been established that when internal waves move from the depth dump to the surf zone, they transform, and their period decreases. When the energy of the internal wave is transformed into elastic bottom vibrations, the flow density is estimated to spread evenly over a shelf about 30 km wide. Taking into account the maximum amplitudes of elastic bottom vibrations caused by offshore internal waves, the density of the seismic energy flux will increase by 2–3 orders of magnitude and will be comparable to the density of the seismic energy flux caused by surface sea waves. Full article