Micro

Quercetin, a flavonoid, has well-proven cytotoxicity potential, but its therapeutic efficacy is hampered by hydrophobicity, stability issues, and lower bioavailability. The present research aims to address these issues and formulation barriers by formulating a quercetin-loaded micellar nanogel. Quercetin was encapsulated in PF 68 micelles to enhance its solubility, loading, and stability to better its therapeutic potential. The nanogel was further characterized regarding for pH, spreadability, and in vitro cytotoxicity against human breast cancer cells (MCF-7). The resulting micelles exhibited a particle size of 180.26 ± 2.4 nm, surface charge of −13.5 mV, entrapment efficiency of 78.4 ± 1.2%, and in vitro release of 96.11 ± 0.75% up to 8 h. This in vitro cytotoxicity study on MCF-7 cell lines reveals the improved TGI and GI 50 values of micellar nanogel formulation compared to quercetin. The overall study results demonstrated that the developed micellar nanogel system might serve as a promising nanocarrier to enhance the cytotoxic potential of quercetin in cancer therapy. Full article

This work determined the resistance of paint formulations containing TiO₂ particles to fungal growth. Siloxane, acrylic and silicone paints were placed outdoors, and the fungal species growing thereon were recorded after 3, 6 and 9 months. In addition, three paint types containing TiO₂ with/without biocide were inoculated with fungal spores and irradiated using UV. Acrylic paints were also doped with different metals and were inoculated and incubated under fluorescent light. Following outdoor incubation, the silicone paint was the least colonised by different fungal species. The species most recovered from the surfaces were Aspergillus spp. and Penicillium spp. Following UV irradiation on different paints containing biocide and/or a photocatalyst, no fungal growth was demonstrated on some of the paint combinations. When the paint samples were doped with different metals and incubated using light, the sample most efficient at preventing fungal growth contained lanthanum (0.004%). The paint samples containing praseodymium (light:1.72) facilitated the densest fungal colonies. Most of the surfaces demonstrated heterogeneous coverage by the fungi. The most clustered fungal colonisation was on surfaces incubated in the light. This work demonstrated that fungal colonisation on paints changed over time and that the antimicrobial efficacy of TiO₂ was affected by the chemical composition, biocide and doping of the paint. Full article

The catalytic conversion of carbon dioxide (CO₂) into carbon monoxide (CO) via the reverse water–gas shift (RWGS) reaction offers a promising pathway toward a sustainable carbon cycle. However, the competing Sabatier reaction presents a significant challenge, underscoring the need for highly efficient catalysts. In this study, we developed a novel catalyst comprising cobalt-oxide-supported nickel-hydroxide nanoparticles (denoted as Co@Ni). This catalyst achieved a remarkable CO production yield of ~5144 μmol g⁻¹ at 573 K, with a CO selectivity of 77%. These values represent 30% and 70% improvements over carbon-supported Ni(OH)₂ (Ni-AC) and CoO (Co-AC) nanoparticles, respectively. Comprehensive physical characterizations and electrochemical analyses reveal that the exceptional CO yield of the Co@Ni catalyst stems from the synergistic electronic interactions between adjacent active sites. Specifically, cobalt-oxide domains act as electron donors to Ni sites, facilitating efficient H₂ splitting. Additionally, the oxygen vacancies in cobalt oxide enhance CO₂ adsorption and promote subsequent dissociation. These findings provide critical insights into the design of highly efficient and selective catalysts for the RWGS reaction, paving the way for advancements in sustainable carbon utilization technologies. Full article

This work addresses a critical challenge in microscale computational electromagnetics for liquid crystal-based reconfigurable components: the inadequate capability of current software to accurately identify and simulate higher-order modes (HoMs) in complex electromagnetic structures. Specifically, commercial simulators often fail to capture modes such as Transverse Electric (TE11) beyond the fundamental transverse electromagnetic (TEM) mode in coaxial liquid crystal phase shifters operating in the terahertz (THz) regime, leading to inaccurate performance predictions and suboptimal designs for telecommunication engineering applications. To address this limitation, we propose a novel diagnostic methodology incorporating three lossless assumptions to enhance the identification and analysis of pseudo-HoMs in full-wave simulators. Our approach theoretically eliminates losses associated with metallic conductivity, dielectric dissipation, and reflection effects, enabling precise assessment of frequency-dependent HoM power propagation alongside the primary TEM mode. We validate the methodology by applying it to a coaxially filled liquid crystal variable phase shifter device structure, underscoring its effectiveness in advancing the design and characterization of THz devices. This work provides valuable insights for researchers and engineers utilizing closed-source commercial simulators in micro- and nano-electromagnetic device development. The findings are particularly relevant for microscale engineering applications, including millimeter-wave (mmW), sub-mmW, and THz systems, with potential impacts on next-generation communication technologies. Full article

Due to their biocompatibility, nontoxicity, and surface conjugation properties, nanomaterials are effective nanocarriers capable of encapsulating chemotherapeutic drugs and facilitating targeted delivery across the blood–brain barrier (BBB). Although research on nanoparticles for brain cancer treatment is still in its early stages, these systems hold great potential to revolutionize drug delivery. Glioblastoma multiforme (GBM) is one of the most common and lethal brain tumors, and its heterogeneous and aggressive nature complicates current treatments, which primarily rely on surgery. One of the significant obstacles to effective treatment is the poor penetration of drugs across the BBB. Moreover, GBM is often referred to as a “cold” tumor, characterized by an immunosuppressive tumor microenvironment (TME) and minimal immune cell infiltration, which limits the effectiveness of immunotherapies. Therefore, developing novel, more effective treatments is critical to improving the survival rate of GBM patients. Current strategies for enhancing treatment outcomes focus on the controlled, targeted delivery of chemotherapeutic agents to GBM cells across the BBB using nanoparticles. These therapies must be designed to engage specialized transport systems, allowing for efficient BBB penetration, improved therapeutic efficacy, and reduced systemic toxicity and drug degradation. Lipid and inorganic nanoparticles can enhance brain delivery while minimizing side effects. These formulations may include epitopes—small antigen fragments that bind directly to free antibodies, B cell receptors, or T cell receptors—that interact with transport systems and enable BBB crossing, thereby boosting therapeutic efficacy. Lipid-based nanoparticles (LNPs), such as liposomes, niosomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs), are among the most promising delivery systems due to their unique properties, including their size, surface modification capabilities, and proven biosafety. Additionally, inorganic nanoparticles such as gold nanoparticles, mesoporous silica, superparamagnetic iron oxide nanoparticles, and dendrimers offer promising alternatives. Inorganic nanoparticles (INPs) can be easily engineered, and their surfaces can be modified with various elements or biological ligands to enhance BBB penetration, targeted delivery, and biocompatibility. Strategies such as surface engineering and functionalization have been employed to ensure biocompatibility and reduce cytotoxicity, making these nanoparticles safer for clinical applications. The use of INPs in GBM treatment has shown promise in improving the efficacy of traditional therapies like chemotherapy, radiotherapy, and gene therapy, as well as advancing newer treatment strategies, including immunotherapy, photothermal and photodynamic therapies, and magnetic hyperthermia. This article reviews the latest research on lipid and inorganic nanoparticles in treating GBM, focusing on active and passive targeting approaches. Full article

This study aimed to characterize the temporal and spatial occurrence of microplastics on the beaches of the Caribbean coast of Limón, Costa Rica. The selected beaches comprise a stretch of 70 km, characterized by large environmental protection areas, agricultural and residential areas with low occupation density, urban areas, and port areas. Despite the great importance of the beaches for the country, studies related to solid waste pollution remain scarce on the Caribbean coast. The methodology consisted of conducting fieldwork in 2017 and 2019 to collect materials on five beaches and laboratory analyses for extraction using hypersaline solution and the quantification and characterization of microplastics based on type, size, and color. The results show that the beaches studied in the northwestern sector had the highest concentrations of microplastics, with emphasis on Cieneguita Beach and Airport Beach, with a predominance of pellets (56.7%) followed by fragments (21.8%). These beaches are inserted in a coastal stretch with a strong concentration of industrial, port, and airport activities. The lower occurrence of microplastics in the southeastern sector (Manzanillo and Gandoca) may be related to the greater number of preservation areas. With varying sizes, shapes, and colors, most microplastics had a worn appearance, which suggests reworking by coastal processes and subsequent deposition on the studied beaches. The impact of this type of pollution on the coast of Limón is notorious and shows the need for further research into the occurrence and distribution of microplastics on Caribbean beaches so that possible sources and damage to coastal ecosystems can be identified. Full article

The non-specific and minimally selective nature of traditional drug administration methods, along with various other limitations, makes the use of drug delivery systems more favorable. Light-responsive, or light-triggered, drug delivery systems provide more controlled and less invasive treatment approaches, addressing the shortcomings of traditional methods. In this paper, we reviewed studies utilizing light-triggered nanoparticles (NPs) for treating cancer and various other diseases, focusing on photodynamic therapy (PDT) and photothermal therapy (PTT) in both in vivo and in vitro applications. Most of the reviewed studies employed synergistic approaches that combined PDT or PTT with other therapeutic methods to leverage the strengths of both techniques and enhance treatment efficiency or to overcome the individual limitations of each method, which is discussed extensively in this paper. Full article

Various electrospinning techniques can be used to produce nanofiber mats with randomly oriented or aligned nanofibers made of different materials and material mixtures. Such nanofibers have a high specific surface area, making them sensitive as sensors for health monitoring. The entire nanofiber mats are very thin and lightweight and, therefore, can be easily integrated into wearables such as textile fabrics or even patches. Nanofibrous sensors can be used not only to analyze sweat but also to detect physical parameters such as ECG or heartbeat, movements, or environmental parameters such as temperature, humidity, etc., making them an interesting alternative to other wearables for continuous health monitoring. This paper provides an overview of various nanofibrous sensors made of different materials that are used in health monitoring. Both the advantages of electrospun nanofiber mats and their potential problems, such as inhomogeneities between different nanofiber mats or even within one electrospun specimen, are discussed. Full article

The colonization of historical buildings and monuments by fungi, algae, and bacteria is a common phenomenon. This often leads to deterioration processes that cause either visual or structural harm. The Batalha Monastery in Portugal, a UNESCO World Heritage Site, currently shows significant surface changes to the stone architectural elements within both the Founder’s Chapel and the church, including a widespread pink discoloration on the walls and columns. The main goal of this study was to analyze the biological colonization and assess the influence of bacterial communities on the biodeterioration of Ançã limestone, providing valuable insights to help conservators and restorers select the best preservation strategies for the monastery. The prokaryote population was characterized using both high-throughput DNA sequencing and culture-dependent methods and several orange-pink pigment-producing bacteria were identified, for example, Bacillus, Gordonia, Serratia and Methylobacterium, as well as Halalkalicoccus, an abundant archaeal genus. The pink discoloration observed could be due to biofilms created by bacteria that produce pigments, namely carotenoids. Biocolonization tests were performed using stone mock-ups, which were prepared and inoculated with the bacteria isolated in this study. These tests were designed to replicate the natural conditions of the monastery and monitor the colonization process to understand the discoloration phenomenon. Full article

In this work, we propose a strategy to optimize electrochemical hydrogen loading in magnesium–palladium thin films, using 5 M KOH as an electrolyte. Mg thin films of thickness 26 nm were deposited on sapphire (0001) substrates and capped by a 32 nm Pd layer. By performing cyclic voltammetry with in situ optical microscopy, it appears that a loading potential of at least −1.2 V vs. Hg/HgO has to be achieved at the sample’s surface to trigger magnesium hydride formation. Loading potential effects are then further explored by hydrogenography, where different hydride formation mechanisms appear based on the actual potential. With a larger loading potential of −1.6 V vs. Hg/HgO, a magnesium hydride blocking layer is formed; in this case, Pd hydride temporarily forms in the capping layer as hydrogen diffuses towards the magnesium layer. Loading is optimized for a lower potential of −1.2 V vs. Hg/HgO, which leads to larger hydride precipitates and delays the blocking layer formation; in this case, Pd hydride only appears after the magnesium layer is completely hydrided. Full article

The reinforcement of cast Cantor’s-type high-entropy alloys by MC carbides and their effect on the hot oxidation behavior were investigated. Three equimolar CoNiFeMnCr alloys without or with carbon and with either hafnium or tantalum were elaborated. Their as-cast microstructures were specified. Oxidation tests were carried out in air at 1100 °C. Flexural creep tests were performed at 1100 °C at 10 MPa. The carbide-free CoNiFeMnCr alloy was single-phased. The version with Hf and C added and the one with Ta and C added contained interdendritic eutectic script HfC and TaC carbides, respectively. After oxidation for 50 h at 1100 °C, all alloys were covered by a (Cr,Mn)₂O₃ scale with various proportions of Cr and Mn. HfO₂ or CrTaO₄ also formed. Oxidation resulted in a deep depletion in Cr and in Mn in the subsurface. Oxidation is much faster for the three alloys by comparison with chromia-forming alloys. Their bad oxidation behavior is obviously due to Mn and protection by coating is to be considered. The creep deformation of the carbide-free CoNiFeMnCr alloy was very fast. The creep resistance of the two versions reinforced by either HfC or TaC deformed much slower. The addition of these MC carbides led to a deformation rate divided by five to ten times. Now, creep behavior comparisons with commercial alloys are to be conducted. They will be performed soon. Full article

Mycoplasma infections pose significant challenges in the poultry industry, necessitating effective therapeutic interventions. Tiamulin, a veterinary antibiotic, has demonstrated efficacy against Mycoplasma species. However, the emergence of resistant Mycoplasma species could dramatically reduce the therapeutic potential, contributing to economic losses. Optimizing the tiamulin’s pharmacokinetic profile via nanocarrier incorporation could enhance its therapeutic potential and reduce the administration frequency, ultimately reducing the resistant strain emergence. Niosomes, a type of self-assembled non-ionic surfactant-based nanocarrier, have emerged as a promising drug delivery system, offering improved drug stability, sustained release, and enhanced bioavailability. In this study, niosomal nanocarriers encapsulating tiamulin were prepared, characterized and assessed in Mycoplasma-inoculated broilers following oral administration. Differential scanning colorimetry (DSC) confirmed the alterations in the crystalline state following components integration into the self-assembled structures formed during the formulation procedure. Transmission electron microscopy (TEM) showed the spherical nanostructure of the formed niosomes. The formulated nanocarriers exhibited a zeta potential and average hydrodynamic diameter of −10.65 ± 1.37 mV and 339.67 ± 30.88 nm, respectively. Assessment of the pharmacokinetic parameters following oral administration to Mycoplasma gallisepticum-infected broilers revealed the ability of the niosomal nanocarriers to increase the tiamulin’s bioavailability and systemic exposure, marked by significantly higher area under the curve (AUC) (p < 0.01) and prolonged elimination half-life (T_1/2) (p < 0.05). Enhanced bioavailability and prolonged residence time are crucial factors in maintaining therapeutic concentrations at reduced doses and administration frequencies. This approach provides a viable strategy to decrease the risk of subtherapeutic levels, thereby mitigating the development of antibiotic resistance. The findings presented herein offer a sustainable approach for the efficient use of antibiotics in veterinary medicine. Full article

Developing new nanomaterials and performing functionalization to increase their photocatalytic capacity are essential in developing low-cost, eco-friendly, and multipurpose-capacity catalysts. In this research, SnO₂/Se-doped quantum dots (QDs) covered with glycerol (SnO₂/Se-GLY) were synthesized using microwave irradiation. Then, their cover was replaced with glutaraldehyde through a ligand exchange procedure (SnO₂/Se-GLUT). The XRD analyses confirmed a tetragonal rutile structure of SnO₂. The HR-TEM analysis confirmed the generation of QDs with a size around 8 nm, and the optical analysis evidenced low bandgap energies of 3.25 and 3.26 eV for the SnO₂/Se-GLY and SnO₂/Se-GLUT QDs, respectively. Zeta-sizer analysis showed that the hydrodynamic sizes for both nanoparticles were around 230 nm (50 mg/L), and the zeta potential confirmed that SnO₂/Se-GLUT QDs were more stable than SnO₂/Se-GLY QDs. The cover-modified QDs (SnO₂/Se-GLUT) showed a higher and faster adsorption capacity, followed by a slower photocatalytic process than the original QDs (SnO₂/Se-GLY). The QTOF-LC-MS analysis confirmed MB degradation through the identification of intermediates such as azure A, azure B, azure C, and phenothiazine. Adsorption isotherm analysis indicated Langmuir model compliance, supporting the high monolayer adsorption capacity and efficiency of these QDs as adsorbent/photocatalytic agents for organic pollutant removal. This dual capability for adsorption and photodegradation, along with the demonstrated reusability, highlights the potential of SnO₂/Se QDs in wastewater treatment and environmental remediation. Full article

The search for new synthesis methodologies based on the principles of green chemistry has led to various studies for the production of silver nanoparticles (AgNPs) using extracts from different parts of plants. Based on this, the present study aims to carry out green synthesis (biosynthesis), characterization, and antibacterial evaluation of reduced and stabilized silver nanoparticles (AgNPs) with aqueous extracts of Minthostachys acris in a simple, ecological, and environmentally safe manner. The extraction process of the organic components is performed using two methods: immersion and the agitation of the leaves of Minthostachys acris Schmidt Lebuhn (Muña) at 0.1% for different times (0.5, 1, 3, 6, and 10 min). Compounds such as hydroxycinnamic acid derivatives, quinic, caffeic, rosmarinic acids, and flavonols present in the Muña extract facilitate the formation of AgNPs; this compounds act as a coating and stabilizing agent. The bioactive components from natural resources facilitate the formation of AgNPs, partially or completely replacing the contaminating and toxic elements present in chemical reagents. The biosynthesis is carried out at room temperature for pH 7 and 8. The synthesized AgNPs are characterized by UV-visible spectroscopy to identify the surface plasmon resonance (SPR) band, which shows an absorption peak around 419 nm and 423 nm for pH 7 and p.H 8, respectively, and Fourier-transform infrared spectroscopy (FTIR) to identify the possible biomolecules responsible for bioreduction and stabilization, with a peak at 1634 cm⁻¹. Dynamic light scattering (DLS) shows the hydrodynamic size of the colloidal nanoparticles between 11 and 200 nm, and scanning electron microscopy (SEM) reveals monodisperse AgNPs of different morphologies, mostly nanospheres, while Laser-Induced Breakdown Spectroscopy (LIBS) demonstrates the presence of Ag in the colloidal solution. The evaluation of the bactericidal activity of the AgNPs using the disk diffusion method against Escherichia coli (E. coli) and Staphylococus aureus (S.aureus) shows that the synthesized AgNPs have effective antibacterial activity against E. coli for the extracts obtained at 6 min for both the immersion and agitation methods, respectively. The significance of this work lies in the use of bioactive components from plants to obtain AgNPs in a simple, rapid, and economical way, with potential applications in biomedical fields. Full article

Micro/nanorobotics is becoming part of the future of medicine. One of the most efficient approaches to the construction of small medical robots is to base them on unicellular organisms. This approach inherently allows for obtaining complex capabilities, such as motility or environmental resistance. Single-celled organisms usually live in groups and are known to interact in many ways (matter, energy, and information), paving the way for potentially beneficial emergent effects. One such naturally expected effect is an increase in the sustainability of a population as a result of a more even redistribution of energy within the population. Our in silico experiments show that under harsh conditions, such as resource scarcity and a rapidly changing environment, altruistic energy exchange (supplying energy to weaker agents) can indeed markedly increase the sustainability of model bacteriabot groups, potentially increasing the efficiency of treatment. Although our work is limited exclusively to the development and use of a phenomenological computer model, we consider our results to be an important argument in favor of practical efforts aimed at implementing altruistic energy exchange strategies in real swarms of single-cell medical robots. Full article

Compacted graphite iron (CGI) attracts significant attention in the automotive industry thanks to its suitable thermomechanical properties and cost-effectiveness. A primary fracture mechanism at the microscale for CGI involves interfacial damage and debonding between graphite inclusions and its metallic matrix, which can occur under high-temperature service conditions due to a mismatch in the coefficients of thermal expansion between these two phases. Such microscopic interfacial damage can initiate macroscopic fractures in cast-iron components subjected to thermal loading. While this phenomenon was studied in various composites, there remains a lack of detailed information for CGI, especially related to the complex morphology of its graphite inclusions. This study investigates the influence of graphite morphology and type of matrix on the thermomechanical performance of CGI at high temperatures. A set of three-dimensional finite-element models were developed in the form of unit cells with a single graphite inclusion embedded within a cubic domain of the metallic matrix. Elastoplastic behaviour was assumed for both phases in the numerical simulations. The study is focused on the response of the constituents in CGI to pure thermal loading in order to explore the relationship between graphite morphology and fracture mechanisms. The findings aim to enhance understanding of how graphite morphology affects the behaviours of CGI under high-temperature conditions. Full article

Carbon dots (C-Dots) have garnered significant attention in various fields, including biomedical applications, photocatalysis, sensing, and optoelectronics, due to their high luminescence, biocompatibility, and ease of functionalization. However, concerns regarding their potential toxicity persist. Conventional synthesis methods for C-Dots often require long reaction times, high pressures, expensive equipment, extreme temperatures, and toxic reagents. In contrast, microwave irradiation provides a rapid, cost-effective, and scalable alternative for the synthesis of high-quality C-Dots. In this study, we report the single-step, 3-min synthesis of water-stable carbon dots at 100 °C, 120 °C, and 140 °C using microwave irradiation. Particle stability was achieved through polyethyleneimine (PEI) functionalization. The toxicity of the synthesized carbon dots was evaluated in marine crustaceans, revealing that C-Dots with an estimated size below 10 nm did not exhibit toxicity after 24 and 48 h of exposure. These findings demonstrate the potential of microwave-synthesized carbon dots as non-toxic, water-stable nanomaterials for environmental and biomedical applications. Full article

Aluminium and its composites are widely used in production to enhance the strength of lightweight objects. In this study, an AA7075/SiC composite was fabricated using a stir casting route. Multi-objective optimization and finite element analysis were performed with various process parameters on a manufactured aluminium composite (AA7075 + SiC) undergoing a laser beam welding process. Four welding parameters, i.e., pulse frequency, power, welding speed (transverse), and wire size were taken for laser welding as per the L-9 orthogonal array for experimental study. Tensile strength, deflection, temperature distribution, Rockwell hardness (fusion zone), and Rockwell hardness (heat affected zone) were taken as output parameters after welding. The standard deviation objective weighting–grey relational optimization method optimized the process parameter. ANSYS APDL 23 software was utilized to simulate the entire laser welding method with a cylindrical heat source to predict the temperature distribution in the butt-welded plates. This software uses finite element analysis and gives a deviation of only 5.85% for temperature distribution with experimental results. This study helps to understand the effect of various parameters on the welding strength of the aluminium composite. Full article