Search Results (21,182)

Magnetic Particle Imaging (MPI) is a new type of tracer-based imaging that has great spatial and temporal resolution, does not require ionizing radiation, and can see deep into tissues by directly measuring the nonlinear magnetization response of superparamagnetic iron oxide nanoparticles (SPIONs). Unlike Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), MPI has very high contrast and quantitative accuracy, which makes it perfect for use in dynamic cardiovascular applications. This study presents a full picture of the most recent changes in cardiac MPI, such as the physics behind Field-Free Point (FFP) and Field-Free Line (FFL) encoding, new ideas for tracer design, and important steps in the evolution of scanner hardware. We discuss the clinical relevance of cardiac MPI in visualizing myocardial perfusion, quantifying blood flow, and guiding real-time interventions. A hybrid imaging workflow, which improves anatomical detail and functional assessment, is utilized to explore the integration of MPI with complementary modalities, particularly MRI. By consolidating recent preclinical breakthroughs and highlighting the roadmap toward human-scale implementation, this article underscores the transformative potential of MPI in cardiac diagnostics and image-guided therapy. Full article

The mechanical performance of cast iron is strongly governed by the morphology of its graphite phase, yet establishing a quantitative link between microstructure and macroscopic properties remains a challenge. In this study, a three-dimensional finite element method (FEM)-based micromechanical framework is proposed to analyze and predict the mechanical behavior of cast iron with representative graphite morphologies, spheroidal and flake graphite. Realistic representative volume elements (RVEs) are reconstructed based on experimental microstructural characterization and literature-based X-ray computed tomography data, ensuring geometric fidelity and statistical representativeness. Cohesive zone modeling (CZM) is implemented at the graphite/matrix interface and within the graphite phase to simulate interfacial debonding and brittle fracture, respectively. Full-field simulations of plastic strain and stress evolution under uniaxial tensile loading reveal that spheroidal graphite promotes uniform deformation, delayed damage initiation, and enhanced ductility through effective stress distribution and progressive plastic flow. In contrast, flake graphite induces severe stress concentration at sharp tips, leading to early microcrack nucleation and rapid crack propagation along the flake planes, resulting in brittle-like failure. The simulated stress–strain responses and failure modes are consistent with experimental observations, validating the predictive capability of the model. This work establishes a microstructure–property relationship in multiphase alloys through a physics-informed computational approach, demonstrating the potential of FEM-based modeling as a powerful tool for performance prediction and microstructure-guided design of cast iron and other heterogeneous materials. Full article

Iron metabolism has emerged as a critical regulator of cancer biology, with mounting evidence linking iron dysregulation to tumor initiation, progression, and resistance mechanisms. Osteosarcoma (OS) is the most common primary bone malignancy and a leading cause of cancer-related death in children and young adults; recent studies have identified profound alterations in iron homeostasis at both cellular and microenvironmental levels in OS. These include increased iron uptake, disrupted storage and export, and a reliance on iron-dependent metabolic pathways that promote proliferation, metastasis, and immune evasion. Despite advances in surgical and chemotherapeutic approaches, survival outcomes in OS have stagnated, underscoring the need for novel therapeutic strategies. Targeting iron metabolism represents a promising avenue, with strategies such as iron chelation, transferring receptor inhibition, ferroptosis induction, and modulation of ferritinophagy, showing preclinical efficacy. In this review, we provide an updated and integrated overview of the multifaceted role of iron in OS pathogenesis, dissect emerging therapeutic approaches aimed at disrupting iron regulatory networks, and highlight innovative delivery platforms including nanomedicine. By integrating current insights on iron metabolism with the molecular complexity of OS, we present a comprehensive perspective, while acknowledging that the limited clinical translatability of current findings still hinders progress toward clinical application. A deeper understanding of iron-driven mechanisms may guide future studies toward the development of safe and effective iron-targeted therapies for OS. Full article

Stress is a non-specific systemic response to internal or external challenges. Recent studies show that stress can disrupt iron metabolism and that iron dyshomeostasis is implicated in many diseases-particularly within the nervous system, where iron distribution and regulation intersect tightly with oxidative stress and inflammation. Activation of the hypothalamic–pituitary–adrenal (HPA) axis by stress can upregulate hepatic hepcidin and reprogram systemic iron fluxes, leading to functional iron deficiency and, in the brain, reduced iron availability, which affects myelination and neurotransmitter metabolism. Conversely, iron dyshomeostasis also contributes to neurodegenerative pathology. In this review, we synthesize recent evidence of how stress reprograms brain iron distribution and regulation, and we outline the mechanistic links between stress-induced iron dysregulation and neurological pathology. We also discuss the therapeutic implications (such as iron-chelation strategies) and highlight the three-way interplay among stress, iron metabolism, and neurodegeneration. These insights suggest that managing iron homeostasis may offer new therapeutic avenues for stress-related neural disorders. Full article

The Água Forte (AF) stream located in the Southern Alentejo region (Portugal), is a tributary of the Roxo river. The AF stream has acid mining drainage (AMD) traits, which contributes to the degradation of the river’s water quality and the adjacent soils. The use of ecological floating beds (EFBs) is an eco-rehabilitation strategy for polluted waters. This work aimed to evaluate the application of EFBs at real-scale as a water treatment system for the AF stream. Thus, three EFB, planted with Vetiveria zizanioides (3.3 m²·unit⁻¹; density 40.5 plants·m⁻²), were placed on the stream. The water quality was monitored monthly, upstream (Inlet) and downstream (Outlet) of EFBs, from May 2020 to November 2021. With the use of the EFBs, the pH remained acidic, and the other main parameters showed average removal rates of around: 8% organic matter; 7% sulphates; 4% chlorides; 18% nitrogen, 30% copper, 29% zinc, 53% iron, and 10% manganese. Inlet and Outlet mass loads correlations showed high removal diversity. For the parameters under analysis, during the treatment period, the removal efficiency showed high variability due to the hydraulic conditions. The higher removal efficiencies were obtained for low-hydraulic retention times, except for heavy metals. Overall, EFBs showed some potential, but their efficiency was variable, highlighting the need for optimization under variable hydraulic conditions. Full article

Background: Minimally invasive hyperthermia and regenerative therapies require materials that deliver precise, localized heat without compromising biocompatibility. Most conventional polymers are thermally insulating and challenging to control in vivo, motivating this review. Objectives: We aimed to (i) examine the use of thermally enhanced biopolymers in hyperthermia-based therapies, (ii) appraise evidence from clinical and preclinical studies, (iii) identify and classify principal applications in regenerative medicine. Methods: A PRISMA-guided systematic review (2020–2025) with predefined inclusion/exclusion criteria was conducted and complemented by a bibliometric analysis using VOSviewer for mapping and visualization. Results: Modifying biopolymers—via functionalization with photothermal or magnetic nanoagents (Au; Fe₂O₃/Fe₃O₄/CoFe₂O₄; CuS; Ag; MXenes, e.g., Nb₂C), crosslinking strategies, and hybrid formulations—significantly increased thermal conductivity, enabling localized hyperthermia and controlled drug release. In vitro and in vivo studies showed that europium-doped iron oxide nanoparticles embedded in chitosan generated heat efficiently while sparing healthy tissues, underscoring the need to balance biocompatibility and thermal performance. Hydrogel systems enriched with carbon nanomaterials (graphene, carbon nanotubes) and matrices such as GelMA, PNIPAM, hyaluronic acid, and PLA/PLGA demonstrated tissue compatibility and effective thermal behavior; graphene was compatible with neural tissue without inducing inflammation. Conclusions: Thermally conductive biopolymers show growing potential for oncology and regenerative medicine. The evidence supports further academic and interdisciplinary research to optimize safety, performance, and translational pathways. Full article

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler–Weber–Rendu disease, is an autosomal dominant vascular disorder caused most commonly by pathogenic variants in the ENG and ACVRL1/ALK1 genes. It is characterized by mucocutaneous telangiectasias and arteriovenous malformations (AVMs) in various organs, leading to recurrent epistaxis, gastrointestinal bleeding, and iron deficiency anemia. Diagnosis relies on the Curaçao Criteria, which include recurrent nosebleeds, characteristic telangiectasias, visceral AVMs, and family history. This review aims to present current therapeutic approaches and emerging treatment strategies for HHT. Traditional surgical and laser-based methods are increasingly complemented or replaced by targeted pharmacological interventions. Antiangiogenic agents such as bevacizumab and thalidomide have demonstrated efficacy in reducing bleeding frequency and transfusion requirements, although adverse effects may limit long-term use. Novel therapies under investigation target molecular pathways involved in vascular remodeling, including tyrosine kinase inhibitors (sorafenib, nintedanib), anti-ANGPT2 antibodies, and modulators of BMP9/ALK1 signaling (tacrolimus, sirolimus). Preclinical and early clinical studies suggest that these agents may provide disease-modifying benefits. Continued research should focus on optimizing treatment efficacy, reducing toxicity, and developing individualized therapeutic regimens based on genetic and clinical characteristics. Full article

2,5-diformylfuran (DFF) is a significant biomass derivative that is employed in a variety of industries. One approach to synthesizing it is through the oxidation of 5-hydroxymethylfurfural (HMF). The challenges in DFF production arise from the need for extreme conditions, issues with overoxidation, and the limitations of noble materials used in neutral or acidic environments. By using a mildly alkaline electrolyte, DFF can be produced electrochemically alongside hydrogen gas generation, eliminating extreme conditions and allowing for the study of a wide range of transition metals. Moreover, the performance of bimetallic electrocatalysts has been studied, and it has been found to be more active in many kinds of processes, particularly Layered Double Hydroxides (LDH). Electrodeposition, once widely chosen among various LDH production methods, is preferred for producing controlled and uniform thin layers. This work examines the electrocatalytic properties of NiCo-LDH and NiFe-LDH in the production of DFF. Cobalt, which exhibits strong adsorption, will be compared to iron, which has a weak adsorption characteristic toward HMF. This study demonstrates that NiCo-LDH gives 1.49 V vs. RHE onset potential, 600 mV lower compared to NiFe-LDH (1.55 V vs. RHE) for HMF oxidation reaction. NiCo-LDH also converts twice the amount of HMF compared to NiFe-LDH for the same amount of charge passed at 0.25 mA/cm⁻² in 0.1 M Na₂B₄O₇. However, strong adsorption promotes reactant activation and reduces the energy barrier while reducing DFF selectivity in NiCo-LDH (23.4%) due to overoxidation, compared to NiFe-LDH (31.6%). In order to achieve optimal electrocatalyst performance, a careful balance of adsorption strength and reaction pathway management is required. Proper optimization of these parameters is essential to improve efficiency and selectivity in the electrocatalytic process. Full article

Coconut yield and quality are significantly affected by multiple female inflorescences (MFF), which disrupt flower differentiation balance. To elucidate the molecular mechanisms, we compared MFF with normal female inflorescences (NFF) using phenotypic, morphological, physiological, and multi-omics approaches. The results revealed that MFF exhibited altered flower structures. MFF showed elevated iron (Fe), nitrogen (N), sulfur (S), potassium (K), calcium (Ca), zinc (Zn), proline (Pro), catalase (CAT), malondialdehyde (MDA), abscisic acid (ABA), and jasmonic acid (JA), but reduced molybdenum (Mo), soluble sugar (SS), soluble protein (SP), superoxide dismutase (SOD), peroxidase (POD), indole acetic acid (IAA), zeatin riboside (ZR), and gibberellic acid (GA). We detected 445 differentially expressed genes (DEGs) mainly enriched in ABA, ETH, BR, and JA pathways in MFF compared to NFF. We identified 144 differentially accumulated metabolites (DAMs) primarily in lipids and lipid-like molecules, phenylpropanoids and polyketides, as well as organic acids and derivatives in the comparison of MFF and NFF. Integrated analysis linked these to key pathways, e.g., “carbon metabolism”, “carbon fixation in photosynthetic organisms”, “phenylalanine, tyrosine, and tryptophan biosynthesis”, “glyoxylate and dicarboxylate metabolism”, “glycolysis/gluconeogenesis”, “pentose and glucuronate interconversions”, “flavonoid biosynthesis”, “flavone and flavonol biosynthesis”, “pyruvate metabolism”, and “citrate cycle (TCA cycle)”. Based on our results. the bHLH137, BHLH062, MYB (CSA), ERF118, and MADS2 genes may drive MFF formation. This study provides a framework for understanding coconut flower differentiation and improving yield. Full article

This study presents the development of a buck–boost converter for application in unmanned guided vehicles (UGVs). The converter was designed with its input connected to a lithium iron phosphate battery pack and its output connected to an inverter. This configuration enabled the inverter, which powered the drive motor, to receive a stable DC voltage, thereby mitigating the effects of battery voltage fluctuations and enhancing the overall system stability. A pulse-width modulation (PWM) controller was employed to regulate the developed buck–boost converter. During the transition from buck mode to buck–boost mode, both power MOSFETs were simultaneously turned on; however, the datasheet of the PWM controller did not provide operational details or characteristic curve analysis for this mode. Therefore, this study derived the relationship between voltage gain and duty cycle ratio for the transition mode. To analyze the input voltage versus duty cycle characteristics, the linear equation was employed. This analytical model was adjusted to meet different converter specifications developed for experimental validation. Furthermore, the external-connect test capacitor method was used to extract the equivalent parasitic inductance and capacitance present in the practical circuit of the buck–boost converter. Based on these parameters, a snubber circuit was designed and connected across the drain–source terminals of the power MOSFETs to suppress voltage spikes occurring at the junctions. Finally, the developed buck–boost converter prototype was installed on an unmanned guided vehicle to convert the power from the lithium battery pack into the input power required by two inverters. A computer host was used to control the motor speed. By measuring the output voltage and current of the buck–boost converter, its electrical functionality and performance specifications were verified. The dimensions of the developed UGV chassis prototype were 40 cm in length, 45 cm in width, and 18.3 cm in height. Full article

Background: Dromedary camel in Saudi Arabia thrive across diverse desert ecosystems where trace minerals are vital for key physiological functions, yet data on how regional and seasonal factors affect these minerals in dams and neonates are limited. Aim: This study investigated the effects of regional and seasonal variability on trace mineral status in dam serum (DS), dam milk (DM), and neonatal serum (NS) across major camel-rearing regions of Saudi Arabia. We hypothesized that environmental factors—particularly heat stress and local feed resources—drive regional and seasonal differences in mineral profiles and maternal–neonatal transfer. Methods: Samples of serum, milk, feed, water, and soil were collected from five major regions during three seasons. Concentrations of selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and iodine (I) were quantified, and correlations among biological compartments were analyzed. Meteorological data were used to compute the temperature-humidity index (THI). Results: The THI ranged from thermoneutral levels in the Northern winter (17.4) to severe heat stress in Eastern summer (33.8). Milk minerals exhibited strong seasonal and regional effects, with selenium peaking in summer and zinc in spring. Western dams showed elevated iron and iodine, whereas northern dams had higher zinc. Serum minerals in dams varied moderately with season but differed regionally for zinc, selenium, and iron. Neonatal serum reflected maternal and regional influences, showing significant season-by-region interactions for selenium and iodine. Positive correlations indicated coordinated maternal–neonatal mineral transfer, particularly for selenium, iodine, and zinc. Feed represented the main environmental source of Cu and Se. In conclusion, camel trace mineral status is mainly driven by environmental factors but regulated through maternal transfer, with selenium and iodine emerging as key heat-stress markers supporting targeted, region- and season-specific supplementation to improve health and productivity in arid regions. Full article

Partial discharge, as an important indicator of insulation degradation in transformers, is a crucial means of assessing the insulation performance of transformers. The existing broadband pulse current detection is easy to install and has no electrical connection with the detection equipment, but it is susceptible to electromagnetic interference from the external environment. Although ultra-high-frequency detection has good anti-interference performance, the installation of its sensors needs to match the structure of the transformer and cannot be applied to partial discharge detection of transformers in operation. This article proposes a research method for detecting ultra-high-frequency partial discharge based on the induction signal of transformer iron core. A transformer iron core simulation model is established based on the time-domain finite-difference method, and the reliable detection frequency band of the iron core for ultra-high-frequency signals of partial discharge is simulated. At the same time, the optimal extraction method of the induction signal is also simulated and studied. The feasibility and effectiveness of the detection method are verified through partial discharge experiments on a physical 110 kV transformer. The results indicate that the transformer core can be used as an ultra-high-frequency sensor for partial discharge detection in the ultra-high-frequency domain. The ultra-high-frequency partial discharge detection method based on a transformer core induction signal is consistent with conventional pulse current and ultra-high-frequency detection. Full article

This study proposes a hybrid flexural strengthening technique for reinforced concrete (RC) beams by combining the near-surface mounted (NSM) and externally bonded reinforcement (EBR) methods. In this technique, iron-based shape memory alloy (Fe-SMA) strips are used for the NSM component, while either a carbon fiber reinforced polymer (CFRP) sheet or an Fe-SMA sheet is applied as the EBR component. The proposed hybrid-strengthening method aims to enhance the flexural load capacity and ductility of existing RC beams. To evaluate the effectiveness of the proposed method, numerical models were developed using ABAQUS software and validated against experimental results. A comprehensive numerical investigation was carried out on 52 RC beams, categorized into six groups with various hybrid-strengthening configurations. In addition, the effect of the prestressing of NSM Fe-SMA strips and the prestressing of EBR CFRP or EBR Fe-SMA sheet on the flexural performance of the beams was also examined. The results indicated that the hybrid-strengthening method significantly improved the cracking, yielding, and ultimate load capacities of the beams; however, in most cases, it reduced their deflection. Notably, prestressing the EBR Fe-SMA sheet in beams with higher reinforcement ratios produced a pronounced improvement in ductility. Full article

Laminated polymer composites have emerged as a promising class of materials that provide exceptional mechanical and functional properties owing to multilayered architectures. In addition, additive manufacturing (AM) offers boundless opportunities to fabricate complex and intricate geometries with a wide variety of materials. Utilizing AM processes for producing laminated polymer composites can open new pathways for producing these intricate structures with fine control over geometry, layer thickness, and material distribution. In this study, we demonstrate the use of the stereolithography (SLA) process to fabricate laminated polymer composites to overcome the limitations of extrusion-based AM processes, i.e., challenges in high precision, strong interlayer bonding and uniform particle distribution. Photocurable polymer composites were prepared by adding different reinforcing particles, i.e., cobalt iron oxide (CoFe₂O₄), graphene (G), magnesium (Mg) and iron (II,III) oxide (Fe₃O₄), into the photocurable resin. Ultrasonication and mechanical mixing processes were used to prepare stable photocurable composites suitable for the SLA process. SLA process was also optimized, varying the process parameters (exposure time, bottom exposure time and bottom layer count) to achieve optimum dimensional accuracy and surface quality. Microscopic analysis confirmed the distinct and well-adhered composite layer sandwiched between the unfilled resin, validating the structural integrity of the multilayer design. Mechanical testing revealed significant improvement in the tensile properties of the laminated composites compared to pure resin, with resin/CoFe₂O₄ exhibiting 35.6% and 50.1% improvement in tensile strength and Young’s modulus compared to the pure resin, respectively. These results highlight the feasibility of SLA for producing multilayered polymer composites with improved mechanical performance and controlled architecture, broadening its potential for advanced engineering and biomedical applications. Full article

This study investigates the influence of sevoflurane and desflurane on the electrochemical behavior of the Fe(III)-acetylacetonate (Fe(acac)₃) complex. Using cyclic voltammetry (CV), we demonstrate that while Fe(acac)₃ exhibits reversible redox behavior in an oxygen-free environment, the presence of dissolved oxygen renders the system irreversible, leading to the formation of a thick, reddish film on the electrode surface upon potential cycling. Notably, the addition of sevoflurane and desflurane restores the electrochemical reversibility and dramatically inhibits this film formation. Raman spectroscopy of the resulting films confirmed structural changes which are consistent with this inhibiting action. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis reveals that the iron in the film remains predominantly in the Fe³⁺ oxidation state even after prolonged electrochemical reduction cycles. These findings suggest that the anesthetics act by inhibiting the interaction between the Fe(acac)₃ complex and oxygen, likely through a spin–decoherence mechanism. This work highlights the critical role of anesthetics in modifying the electrochemical behavior of metal-oxygen complexes, with potential implications for sensing, electrocatalysis, and bio-oriented systems. Full article