Search Results (4,173)

The increasing amount of untreated electronic waste, particularly in the telecommunications sector, is having a negative impact on the environment, not only by increasing the production of greenhouse gases, but also by reducing the availability of resources such as metals. At the same time, these metals are increasingly in demand to meet the manufacturing needs of new technologies. One solution is to recover metals by recycling end-of-life electronic boards. However, current processes are often implemented by large companies but are not suitable for small organizations or those with fewer resources, thus limiting their participation in local electronic waste management. Based on laboratory-scale analyses, this project compares the metal concentration results of three pre-treatments that could be suitable for smaller organizations: magnetic separation, chemical pre-treatment with sodium hydroxide, and centrifugation. The proposed preparation step, after the shredding of telecom electronic boards down to a particle diameter of less than 1 mm, is two-stage centrifugation. This pre-treatment enables metals to be concentrated efficiently and safely prior to hydrometallurgical processing. Full article

Objectives: Concentrated pills, as a modernization and upgrade of traditional pills, have achieved significant advancements in dosage form. However, their extended disintegration and dispersion times have become a major limitation to their therapeutic efficacy. Therefore, an in-depth study and explanation of the dissolution mechanism of concentrated pills, along with the development of processing technology to control dissolution time, has emerged as a critical bottleneck in improving the quality of concentrated pills. Methods: In this study, the Liuwei Dihuang (LWDH) concentrated pill, derived from the classical Liuwei Dihuang pill, was selected as a representative model. Two drying methods—hot-air drying and hot air–microwave combined drying—were comparatively investigated to evaluate their effects on dissolution time. The dissolution behavior was elucidated by analyzing water migration during the dissolution process, as well as the textural properties and internal structural characteristics of the pills using Low-Field Nuclear Magnetic Resonance (LF-NMR), Micro-Computed Tomography (Micro-CT), texture analysis, and other modern techniques. Results: The results indicated that: (i) The rate of water absorption during the dissolution process of the LWDH pill was influenced by the number and size of the internal pores. (ii) Hot air–microwave combined drying results in more pores and faster dissolution. (iii) High-Performance Liquid Chromatography (HPLC) fingerprints showed no significant differences in the active ingredients between the samples. Conclusions: The drying method significantly affected the internal structure of the pills, suggesting that controlling the drying process could address the prolonged dissolution time of concentrated pills. Full article

This study investigates the enhancement of hydrogen production efficiency in water electrolysis through the application of external magnetic fields. A series of controlled experiments were conducted using four distinct electrode materials—stainless steel (SS), low-carbon steel (LCS), titanium (Ti), and platinum-plated titanium (Ti/Pt)—to identify the optimal configuration for maximizing gas output. The research evaluated the influence of electrolyte concentration (KOH), current density, and magnetic field intensity ranging from 0 to 1800 G. Our findings indicate that the application of a 200 G magnetic field leads to a notable 6% increase in the rate of gas production compared to non-magnetized conditions. Specifically, a magnetic field oriented parallel to the electrode plates outperformed a perpendicular orientation by approximately 5%, a phenomenon attributed to the Lorentz force facilitating ionic mass transfer and gas bubble detachment. Furthermore, the integration of ion-exchange and proton-exchange membranes (MC-3470 and N-117) effectively isolated the anodic and cathodic products, elevating hydrogen purity from 67.4% to approaching 100% without compromising electrolysis efficiency. These results demonstrate that the strategic coupling of moderate magnetic fields with optimized electrode configurations provides a promising pathway for improving the efficiency and cleanliness of hydrogen production, which is essential for its role as a sustainable energy carrier. Full article

The plague, caused by Yersinia pestis, has resulted in significant mortality over the past century. Despite advances in antimicrobial therapy, plague remains a re-emerging infectious disease with ongoing outbreaks and increasing concerns regarding antimicrobial resistance. Today, plague cases are still being reported, and the loss of effectiveness of treatment methods remains a major challenge. Therefore, effective treatment strategies are needed. In this study, we aimed to develop aptamers specific to Yersinia outer protein M (YopM), a key immunosuppressive protein that is essential for virulence. Our goal was to develop an aptamer that binds to YopM and inhibits its interaction with the human DEAD-box helicase 3 (DDX3) protein. YopM-DDX3 protein interaction was targeted because of its key role in nucleocytoplasmic shuttling of YopM. To achieve this, we developed the YopM16 aptamer using magnetic bead-based (Systematic Evolution of Ligands by Exponential Enrichment) (SELEX). The selected YopM16 aptamer exhibited a half-maximal inhibitory concentration(IC₅₀) value of 103.3 ± 2 nM and effectively inhibited the interaction between YopM and DDX3. The inhibitory effect of the aptamer on protein interaction was confirmed using a pull-down assay and colorimetric test. Given that protein–protein interaction surfaces are considered undruggable, YopM16 is a promising inhibitor with the potential to serve as a molecular tool to investigate the virulence mechanism of YopM, as well as a novel antibacterial agent upon validation of its inhibition in cellular models. Full article

This study investigates the synthesis and kinetic behavior of a magnetic biochar derived from avocado seed biomass for the removal of hexavalent chromium (Cr(VI)) from aqueous solutions. Magnetite (Fe₃O₄) was synthesized through different routes, including nitrogen-assisted coprecipitation, redox-controlled coprecipitation, polyol, sol–gel, and sonochemical methods, to evaluate their structural properties and iron incorporation efficiency. Based on compositional and crystallographic analyses, the coprecipitation under an inert atmosphere exhibited improved phase purity and higher Fe₃O₄ content, which was selected for in situ incorporation onto biochar produced by pyrolysis at 450 °C. The resulting magnetic material and composite were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), confirming the suitability of the synthesis method and the successful deposition of magnetite onto the porous carbon matrix while preserving its structural integrity. Batch adsorption experiments were conducted at pH 2.0 to evaluate the effect of adsorbent dose and initial Cr(VI) concentration. The adsorption process reached equilibrium within 120 min and was better described by the pseudo-second-order kinetic model (R² ≥ 0.98), suggesting that chemisorption governs the rate-controlling step, with diffusion phenomena contributing but not dominating the overall mechanism. The maximum adsorption capacity predicted by the kinetic model reached 42.49 mg g⁻¹ at an initial concentration of 100 mg L⁻¹. The results demonstrate that avocado-seed-derived magnetic biochar represents a sustainable and effective material for chromium-contaminated water treatment, integrating agro-industrial waste valorization with enhanced adsorption performance and magnetic separability. Full article

Due to the widespread use of microwave electromagnetic radiation, this study examines the microwave electromagnetic properties and compressive strength of composites made from inexpensive components such as Mg_0.5Zn_0.5Fe₂O₄, polystyrene, and activated carbon. Experimental samples were fabricated using thermopressing. The formation of the dielectric core/shell structure for Mg-Zn/polystyrene composites (1:1) and composites with activated carbon additives at weight concentrations of 3, 6.6, and 9.0% was determined using SEM image analysis. Microwave properties were investigated by analyzing the frequency dependences of complex permittivity and magnetic permeability in the frequency range of 100 MHz–5 GHz. As shown by the simulation and experimental measurements of scattering parameters obtained, the compost shows improved microwave absorption properties in the frequency range of 1–5 GHz. Reflection loss spectra showed peaks with values of −17.8 and −18 dB in the frequency range of 2.5–5 GHz for samples with 4.8 wt. % and 6.6 wt. % carbon loading, respectively. The absorption bandwidths of −10 dB in the range of 1.7–2.13 GHz were observed in the best samples. Studies have shown that samples containing 9.0 wt. % of carbon material with thicknesses of 6–10 mm can be considered as an electromagnetic shielding material in the microwave range 1–5 GHz. It was shown that, despite a decrease in porosity from 15.59 to 7.17%, with an increase in the concentration of carbon material in the composites, the compressive strength also decreases from 62.05 to 36.45 MPa. The developed composites are potentially suitable as microwave absorbers for civil applications. Full article

This study investigates the effect of complex nanomodification combined with the simultaneous application of magnetic fields and mechanical vibration on the structure formation and performance properties of medium-alloy steel 40CrNi3MoV. Improving the structural homogeneity and operational characteristics of such steels remains an important task due to their widespread use in components operating under severe loading and wear conditions. The introduction of the nanostructured modifier InSteel-7 at a concentration of 0.03%, together with simultaneous magnetic and vibrational treatment of the melt, resulted in pronounced structural homogenization and grain refinement. Quantitative metallographic analysis using Thixomet Pro image analyzer revealed a significant refinement of the dendritic structure, with the secondary dendrite arm spacing decreasing from 73.9 μm to 27.9 μm. X-ray phase analysis confirmed the preservation of phase composition while indicating increased structural uniformity of the BCC matrix. Energy-dispersive spectroscopy and elemental micro-mapping demonstrated high chemical purity of the alloy and a uniform distribution of the modifier components. The combined treatment significantly improved the mechanical and tribological characteristics of the material. The average hardness increased from 390 HV to 510 HV, while tribological tests showed a reduction in wear track depth from 5.16 μm to 0.87 μm and a decrease in surface roughness from Ra 2.13 μm to 0.20 μm, indicating enhanced wear resistance. Full article

Meningovascular syphilis, a type of neurosyphilis, causes stroke and various types of myelopathy. In recent years, there has been an increase in the incidence of neurosyphilis. However, diagnosing neurosyphilis remains challenging due to the reliance on serum and cerebrospinal fluid (CSF) testing, which has low specificity and sensitivity. Magnetic resonance vessel wall imaging (MR-VWI), recently developed to identify vessel wall pathologies, may aid in diagnosing neurosyphilis. In this cross-sectional study, we performed systematic screening for syphilis in all 366 patients with acute ischemic stroke or transient ischemic attack admitted to our stroke unit. Further CSF analysis and MR-VWI were specifically conducted only on those with reactive serum venereal disease research laboratory (VDRL) or treponema pallidum particle hemagglutination assay (TPHA) tests to evaluate neurosyphilis. Serum screening was reactive in 5.7% (21/366) of patients; among these, the prevalence of likely neurosyphilis (defined by abnormal CSF pleocytosis or protein levels) was 2.2% (8/366). Within this group of eight patients, MR-VWI was technically feasible and thus performed in six cases. Although all CSF-VDRL tests were non-reactive, MR-VWI identified diagnostic evidence of meningovascular syphilis (concentric wall thickening and enhancement) in 33.3% (2/6) of symptomatic patients who underwent the scan. Neurosyphilis remains a critical, treatable cause of stroke that can affect older patients with established vascular risk factors. Our findings demonstrate that routine serum screening is essential, as traditional CSF-VDRL tests may yield false-negative results. MR-VWI serves as a valuable adjunct tool to provide objective evidence of active vasculitis, guiding the initiation of appropriate antibiotic therapy when laboratory results are inconclusive. Full article

The global seafood industry faces persistent challenges related to product quality, safety, and authenticity, driven by complex supply chains, increasing demand, and the perishable nature of aquatic products. Traditional analytical methods often fall short in providing rapid, comprehensive, and non-destructive insights into the intricate biochemical changes occurring in seafood. ¹H Nuclear Magnetic Resonance (¹H NMR) spectroscopy has emerged as a powerful and versatile tool for metabolomics, offering a holistic view of the low-molecular-mass compounds (metabolites) present in biological samples. The present study applied ¹H NMR for chemical fingerprint identification in mullets (Mugil liza) from Brazil. Dorsal muscle samples were taken from the fish during summer, autumn, and winter. The procedure involved freeze-drying the muscle tissue, thereafter extracting polar metabolites using designated solvents (methanol, water, and chloroform), and analyzing them using a 600 MHz spectrometer. As a result, 23 metabolites related to degradation biomarkers, essential metabolites, energy expenditure, and muscle structure were identified. The statistical analysis demonstrated a distinct separation between the geographical origins (RJ vs. SC), mostly influenced by variations in the concentrations of lactate, histidine, threonine, phenylalanine, and ornithine. Factors like fish size and seasonal variations did not markedly affect the overall metabolic profile, underscoring the reliability of these chemicals as stable origin indicators. The Principal Component Analysis identified two distinct groups of metabolites, establishing a profile for each geographical origin. The developed protocol can be applied to the processes of geographical identification. Thus, the ¹H NMR tool was efficient in determining metabolites that can be considered biomarkers in analyses for seafood traceability. Full article

As critical equipment in the petroleum industry, coiled tubing is prone to safety hazards, including stress concentrations and fatigue failure, under complex operating conditions. An online enhanced metal magnetic memory detection method was employed to reduce noise in surface magnetic field signals from tubing subjected to 35 MPa of internal pressure across different fatigue cycles. Conventional signal processing methods have difficulty effectively extracting characteristic magnetic field signals in high-noise environments; therefore, a comprehensive comparison of the noise reduction effectiveness of five common signal processing techniques in stress-distorted regions was conducted, an in-depth analysis of the limitations of different methods was performed, and a hybrid noise reduction framework combining wavelet threshold denoising (WTD) and sequential variational modal decomposition (SVMD) was established. Concurrently, the whale optimization algorithm (WOA), which possesses global search capabilities and demonstrates good adaptability to multi-parameter coupling issues in hybrid denoising frameworks, was innovatively proposed for key parameter optimization. Using fuzzy entropy (FE) as an evaluation metric, the experimental results demonstrated that magnetic field signals in all directions achieved at least a 1.03% reduction in FE and a minimum increase of 33.1% in integrated side lobe ratio (ISLR). This provided effective technical support for reliably detecting stress-distortion zones on coiled-tubing surfaces and established the engineering necessity of implementing preventive maintenance. Full article

Background/objectives: Although informative, current insights into the inflammatory nature of colorectal cancer (CRC) have yet to have a meaningful impact on the prevention of, and development of novel therapies for, the treatment of this prevalent and challenging disease. Accordingly, the current study was focused on identifying putative, key, systemic, mostly pro-inflammatory biomarkers of metastatic CRC (mCRC) prognosis and outcome. Methods: Patients with mCRC (n = 38) and matched healthy controls (n = 30) were recruited to the study. A multiplex magnetic bead array system and an ELISA procedure were used to measure the plasma concentrations of selected cytokines (n = 25) and that of C-reactive protein (CRP) by immunonephelometry. Systemic inflammatory indices (n = 5) were derived from the hematological data. Results: Plasma levels of 17/25 of the cytokine biomarkers and CRP were found to be significantly elevated, while the neutrophil/lymphocyte ratio proved to be the most useful of the various inflammatory indices. Subgroup analysis of the data derived from the group of mCRC patients revealed that the intensity of the systemic inflammatory response was mostly unaffected by tumor location, age, gender, and treatment line. The exception was time to progression, with a shorter time (<120 days) being associated with increased levels of IL-6, IL-8 and TNF-α. Hierarchical cluster analysis of the data revealed a possible association with a small group of four cytokines, comprising IL-1β, IL-13, IL-6/CRP and TGF-β1. Conclusions: This study confirms a strong association of established mCRC with cytokine-driven systemic inflammation. Four of these cytokines, IL-1β/IL-13 IL-6/CRP, and TGF-β1, appear prominent and are possibly indicative of novel targetable therapeutic options. Full article

The preparation of new magnetic materials is important because of their potential application in various electronic components. In the present work, the synthesis of glass-crystalline materials in the system Na₂O-MnO-SiO₂-Fe₂O₃ prepared by applying melt-quenching is reported. The phase composition as studied by X-ray diffraction and Raman spectroscopy reveals the precipitation of monophase Mn_xFe_3−xO₄ based solid solutions. The microstructure is studied by scanning electron and optical microscopy and shows bulk crystallization and the presence of polygon-shaped as well as of dendritic crystals, depending on the iron oxide concentration and used raw materials. Mössbauer spectra show that in the amorphous matrix the Fe ions are mainly present as Fe³⁺ in tetrahedral coordination and as Fe³⁺ in a solid solution with the composition Mn_xFe_3−xO₄. The simultaneous presence of MnFe₂O₄ (jacobsite) and a Mn-containing solid solution based on Fe₃O₄ (magnetite) is suggested. The room temperature magnetic properties were studied by vibrating sample magnetometer and reveal ferrimagnetic properties for all investigated glass-crystalline materials. Full article

This study investigates unsteady magnetohydrodynamic free convection flow past a rotating vertical plate embedded in a Darcy–Forchheimer porous medium. The formulation incorporates Hall current, thermal radiation, viscous dissipation, Joule heating, and an Arrhenius-type chemical reaction with activation energy to represent thermo-reactive transport in an electrically conducting fluid. The coupled nonlinear equations governing momentum, thermal energy, and species concentration are transformed into dimensionless form and solved numerically using the Crank–Nicolson scheme. Grid independence and validation tests confirm the accuracy and stability of the numerical procedure. The results show that electromagnetic forces, rotation, porous resistance, and thermo-reactive effects significantly influence wall shear stress, heat transfer, and mass transport. In particular, the interaction between magnetic field strength and Hall current alters near-wall transport behavior, highlighting the role of electromagnetic coupling in rotating porous systems. The study provides physical insight relevant to the design and analysis of transport processes in high-temperature energy systems, rotating reactors, and porous thermal management devices. Full article

A previously unexplored magnetic biocomposite (CMC-HSDs/Fe₃O₄) was developed through the valorization of hydrophobic scleroprotein discards (HSDs). The synthesized material was evaluated for its efficacy in the adsorption of Cr(VI) and Hg(II) ions from contaminated aqueous systems. The physicochemical properties of the synthesized CMC-HSDs/Fe₃O₄ nanocomposite were characterized using XRD, FTIR, BET, TG/DTG, FESEM, EDX, and elemental mapping. Subsequently, a Box–Behnken experimental design was employed to model and optimize the adsorption process for Cr(VI) and Hg(II), focusing on the critical parameters of solution pH, adsorbent dosage, and interaction time. Kinetic data were best fitted to the pseudo-first-order (PFO) model. Equilibrium isotherm analysis revealed that Cr(VI) adsorption followed the Langmuir model, while Hg(II) adsorption was better fitted by the Freundlich model. Advanced ionic calculations elucidated a consistent multimolecular adsorption mechanism for both ions, characterized by temperature invariance and a preferential vertical geometry of the adsorbed species. Through a production cost of 25.56 USD/kg, the biosorbent demonstrates excellent reusability, retaining 88.60% efficiency for Cr(VI) and 85.69% for Hg(II) after five adsorption–desorption cycles. Based on a 50 mg/L influent concentration, projected treatment costs are ~$3.50/100 L for Cr(VI) and ~$1.22/100 L for Hg(II), underscoring the nanocomposite’s economic feasibility for industrial deployment in advanced tertiary wastewater remediation. Full article

Heavy metal contamination of foods remains a persistent global challenge for food safety and public health, driven by industrialization, mining activities, intensive agriculture, and ongoing environmental degradation. This scoping review synthesizes peer-reviewed literature on the occurrence of priority toxic metals—arsenic, cadmium, lead, mercury, and nickel—in food matrices, with emphasis on contamination pathways, analytical detection strategies, and documented human health effects. The reviewed studies reveal widespread accumulation of heavy metals in staple foods, including cereals, vegetables, seafood, and processed products, with concentrations frequently approaching or exceeding international regulatory limits, particularly in regions exposed to strong anthropogenic pressure. Conventional laboratory-based techniques, such as atomic absorption spectrometry and inductively coupled plasma methods, remain the reference standards for quantitative determination and regulatory compliance; however, their application to large-scale or continuous monitoring is often constrained by cost, infrastructure, and operational complexity. Consequently, increasing attention has been directed toward emerging detection approaches, including portable X-Ray fluorescence, Raman/SERS spectroscopy, electrochemical biosensors, electronic tongues, and in situ magnetic measurements, as complementary tools for rapid screening and field-based surveillance. Among these, environmental magnetism and in situ magnetic techniques stand out as non-destructive, low-cost proxies capable of identifying metal-associated particulate contamination linked to food production systems. Chronic dietary exposure to heavy metals is consistently associated with neurotoxicity, nephrotoxicity, carcinogenicity, and oxidative stress, underscoring the need for integrated, multi-tiered monitoring frameworks to support early detection, risk assessment, and prevention. Full article