Search Results (2,878)

Oil-contaminated soils represent a significant environmental challenge due to the presence of petroleum hydrocarbons and associated pollutants. At the same time, such materials may contain valuable hydrocarbon-rich organic fractions that can potentially be recovered and reused. In this study, the organic phase extracted from oil-contaminated soil was investigated as a secondary hydrocarbon resource for the production of bitumen-like materials. The extracted organic phase was subjected to thermal oxidation to obtain a bitumen-like material, followed by modification using road bitumen (BND 50/70) and an SBS polymer. The resulting bitumen-like material exhibited improved performance after modification, with the softening point increasing from 32.1 to 40.6 °C, the rotational viscosity from 3.11 to 101.5 Pa·s, and enhanced high-temperature rutting resistance. The structural and compositional characteristics of the obtained materials were analyzed using FTIR spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and Saturates, Aromatics, Resins, and Asphaltenes (SARA) fractionation. Physicomechanical and rheological properties were evaluated using penetration, softening point, rotational viscosity, and dynamic shear rheometer (DSR) measurements. The results indicate the presence of aliphatic and aromatic hydrocarbon-rich structures characteristic of petroleum-derived materials. Modification with road bitumen and SBS resulted in redistribution of SARA fractions and improved physicomechanical and rheological properties, including increased softening point, higher viscosity, and enhanced resistance to permanent deformation at elevated temperatures. Overall, the obtained results demonstrate that oil-contaminated soils can be considered a promising secondary source of hydrocarbon-rich raw materials. The proposed approach combines waste remediation with resource recovery and supports the development of sustainable technologies for the utilization of petroleum-containing wastes within a circular economy framework. Full article

Iron, with the unique stability of its nucleus, occupies an unusual position among the elements: its abundance on Earth is not simply a geological accident but a direct consequence of nuclear reactions that happened inside stars billions of years ago. Formed at the final stages of fusion in stars, iron spread through space by supernova explosions and became part of the material that formed Earth, eventually becoming the dominant component of the planet’s core. At the surface, iron’s redox chemistry shaped the early atmosphere and oceans, and its availability as a soluble ferrous ion in the anaerobic Archean ocean made it a natural cofactor for the first enzymatic reactions. That same redox flexibility and the ability of iron to shuttle between Fe²⁺ and Fe³⁺ across a wide range of electrochemical potentials explain why virtually every major metabolic pathway in biology depends on iron in one form or another. Yet iron is also dangerous: free and chelated iron can catalyze the production of toxic hydroxyl radicals through Fenton chemistry, the reactivity of which depends strongly on the nature of the chelating ligand, and every living system must balance its need for iron against the oxidative damage that uncontrolled iron causes. This tension between catalytic necessity and chemical toxicity has driven much of the regulatory complexity we observe in modern iron metabolism. In this review, we first outline iron’s journey from its formation in stars to its role in shaping Earth’s structure and the emergence of early iron-dependent biology. We then discuss in detail how fundamental physical and chemical factors continue to influence living systems. Full article

The rapid development of Generation IV nuclear reactors has imposed stringent requirements on structural materials, demanding excellent irradiation resistance to withstand long-term exposure to complex radiation environments, including neutron and ion irradiation. Under irradiation, a large number of defects are generated inside materials via displacement cascades, and the dynamic evolution of these defects gradually leads to macroscopic property deterioration, potentially triggering major accidents such as equipment failure and even posing system safety hazards. Thus, understanding the law of defect evolution in materials under irradiation and exploring the microscopic mechanism of irradiation damage are core prerequisites for material service life prediction, radiation resistance optimization, and safety risk assessment. In recent years, computational simulation, leveraging its unique advantages in multiscale and multiphysics coupling research, has yielded numerous innovative achievements in the irradiation field. This review overviews the progress of computational simulation studies on irradiation damage in nuclear structural materials over the past few decades, focuses on summarizing the “generation-evolution-annihilation” process of irradiation defects, and further discusses the impact of irradiation on the macroscopic mechanical properties of materials. The content and outlook of this review can advance the microscopic-level comprehension of irradiation damage mechanisms in structural materials and provide guidance for the development of a new generation of materials with excellent irradiation resistance. Full article

This article proposes an approach for acquiring HSQC (Heteronuclear Single Quantum Coherence) spectra using a high-resolution probehead originally designed for solutions. The method is suitable for studying organic substances with relatively low melting points, such as copolymers, composites, waxes, resins, and similar materials. The procedure involves preparing a melt of the substance directly inside the NMR (Nuclear Magnetic Resonance) sample tube prior to analysis. A comparison of HSQC spectra obtained from both the molten state and a solution of the same substance demonstrates that representative spectra can be acquired, enabling detailed analysis of their fine structure. The method has been successfully tested on a range of materials, including: paraffin, wax, honey, vanillin, polycaprolactone, a copolymer of lactide with phenol and maleic anhydride, composites of polycaprolactone and vanillin. This approach enables the identification of impurities in polymers and biological samples without requiring expensive deuterated solvents. Full article

This study primarily aimed to evaluate how the chemical form and carrier medium of radionuclide contamination influence the effectiveness of skin decontamination procedures. In addition, the study sought to identify decontamination strategies that align with recommended practices while reducing reliance on intensive mechanical cleaning methods. Although skin damage was not directly evaluated, the findings provide valuable information for improving the safety of decontamination procedures used by personnel handling radioactive materials and by emergency responders involved in radiological and CBRN (Chemical, Biological, Radiological, and Nuclear) incidents. Accidental spills of radiopharmaceuticals in laboratories and medical facilities, as well as contamination associated with uranium mining, fuel-cycle operations, spent fuel management, and the decommissioning of nuclear facilities, may involve radioactive isotopes present in a variety of chemical forms and solutions. Fresh porcine skin was used as an experimental model, and skin temperature was maintained at 37 °C to simulate physiological conditions. Europium-152 (¹⁵²Eu) was selected as the model radionuclide. Deionized water, concentrated nitric acid (HNO₃), saturated sodium hydroxide (NaOH) solution, and ethanol were used as carrier media representing different chemical environments of ¹⁵²Eu contamination. To simulate realistic contamination scenarios, contaminating solutions were allowed to dry on the skin surface before decontamination. The influence of contaminant chemistry, carrier medium, and drying conditions on radionuclide penetration and subsequent decontamination effectiveness was investigated. Particular attention was given to the extent to which different physicochemical forms of contamination affected radionuclide removal from the skin. The results demonstrated that the chemical form of the contaminant and the drying conditions were key factors determining decontamination efficiency. Among the tested methods, a decontamination kit consisting of a soap-based solution, the complexing agent DTPA, and an absorbent non-woven swab achieved the highest radionuclide removal efficiency. These findings indicate that successful radionuclide decontamination depends strongly on the physicochemical properties of the contaminant. The combined use of a complexing agent, detergent-based formulation, and absorbent material can significantly enhance radionuclide removal from contaminated skin surfaces. Furthermore, the study highlights the importance of considering contaminant chemistry when developing effective and safe decontamination protocols for radiological and CBRN incidents. Full article

Lead-free polymer composites containing high-atomic-number fillers are promising alternatives to conventional lead shielding for nuclear medicine applications. In this study, Bi₂O₃-, WO₃-, and hybrid Bi₂O₃/WO₃ nanoparticle-filled epoxy resin composites were fabricated and evaluated for attenuation of the 140 keV photons emitted by technetium-99m (Tc-99m). The synthesized Bi₂O₃ and WO₃ nanoparticles exhibited hydrodynamic diameters of 638.2 ± 11.3 and 404.2 ± 3.2 nm, respectively, with polydispersity indices below 0.30 and zeta potentials of −33.73 ± 0.63 and −32.47 ± 0.75 mV, indicating acceptable dispersion characteristics and colloidal stability. SEM–EDX confirmed successful incorporation of Bi- and W-containing phases into the epoxy matrix, while the XRD and FTIR analyses verified retention of the crystalline metal oxide phases and the principal chemical structure of the cured epoxy network. Tensile testing revealed a composition-dependent strength–ductility relationship, with the Bi₂O₃-filled composite exhibiting the highest tensile strength among the developed formulations and the hybrid composite showing the greatest elongation at break. XCOM and Phy-X/PSD simulations demonstrated that increasing high-Z filler content enhanced the mass and linear attenuation coefficients and reduced the half-value layer, tenth-value layer, and mean free path. Experimental shielding performance was evaluated using Hp(10) measurements with optically stimulated luminescence dosimeters positioned on an anthropomorphic thorax phantom under a fixed Tc-99m exposure geometry. The transmitted dose decreased with increasing filler loading, and nanoparticle-filled formulations generally outperformed the corresponding conventional-particle composites. The hybrid 75:25 Bi₂O₃/WO₃ NP composite exhibited the lowest mean Hp(10) value of 0.016 µSv, corresponding to a 50% reduction relative to the lead reference under the investigated geometry. The combined structural, mechanical, computational, and dosimetric results demonstrate that hybrid filler design enables simultaneous optimization of attenuation efficiency and mechanical tolerance. These findings identify the Bi-rich hybrid epoxy composite as a promising lead-free material for customized shielding components, including vial holders, syringe-shield housings, protective panels, and workstation accessories used during Tc-99m handling in nuclear medicine. Full article

Background: Efficient DNA extraction from degraded skeletal remains is essential for forensic and ancient DNA analysis. The main aim of this study was to compare the performance of an automated DNA extraction system with a manual DNA extraction protocol when applied to challenging skeletal samples. Specifically, the automated Maxwell Forensic Sample Concentrator system was evaluated against a modified manual Dabney extraction protocol. Methods: DNA was extracted from skeletal material originating from twelve human individuals. Maxwell extractions using 50 mg and/or 100 mg of starting material were compared with Dabney extractions using 50 mg. DNA extracts were quantified using SD quants targeting nuclear DNA and two mitochondrial DNA fragments. Selected extracts were further analysed by mitochondrial DNA sequencing. Results: Both extraction approaches generated comparable DNA yields and sequencing results for moderately degraded samples. In the highly degraded samples analysed in this study, the Dabney protocol generally yielded higher nuclear and mitochondrial DNA quantities and was often associated with a higher sequencing performance. The Maxwell system nevertheless performed well for less degraded material and, in some cases, produced sequencing results comparable to Dabney. Maxwell extraction with 100 mg input was effective for better-preserved samples but was less consistent for highly degraded material. Conclusions: The efficiency of the extraction methods depended largely on the degree of DNA degradation. The findings of this study suggest that the Dabney protocol may be more suitable for heavily degraded skeletal remains, whereas the automated Maxwell system represents a practical and efficient option for less degraded samples. The choice of method therefore depends on the sample condition and the analytical objectives. Full article

Functional coatings have evolved from their early role as passive barriers against corrosion and wear into engineered interfaces that actively mediate the interaction between a bulk material and its environment. This review traces the evolution of coating technologies from traditional macroscopic protective layers to nanoscale and multifunctional systems, and finally to smart and stimuli-responsive architectures. Advanced deposition and surface modification techniques are examined, including atomic layer deposition, physical vapor deposition, electrochemical and sol–gel approaches. The discussion is structured around two complementary application domains: extreme energy environments, focusing on coatings developed for advanced nuclear systems, and modern medical implants, including bioactive and antimicrobial surfaces and drug-delivery interfaces. The review highlights that, despite the differences between reactor and biomedical environments, both sectors share a common set of design principles and challenges, including interfacial adhesion, mechanical durability, the dual role of nanostructuring, and the trade-off between architectural complexity and operational reliability. Long-term stability, scalability, and standardized validation remain key barriers to deployment, while data-driven design and the deliberate integration of multiple functions emerge as the principal directions for future development. Full article

Silica gel polymer material with imprinted phosphate cavities was successfully obtained using one-pot sol–gel reaction. Differences in the textural properties concerning the reduction in specific area and pore size between functionalized and pristine silica gel demonstrated the presence of the phosphate moieties in the cavities. The chemical and structural characterization of the functionalized material before and after copper adsorption was performed by Fourier-transform infrared spectroscopy (FTIR) and solid-state ²⁹Si and ³¹P nuclear magnetic resonance (NMR) spectroscopy. All these measures proposed a phosphate non-covalently bound in the cavities of the silica gel and stabilized by silanol groups on the surface of the matrix. The phosphate–copper complex is removed after the metal desorption process, and the free cavities in the silica matrix can be replenished with phosphoric acid without affecting its adsorption capacity. The entire process of phosphate incorporation, copper adsorption, and metal-ligand desorption was repeated in three cycles, showing a similar metal adsorption capacity. Energy-dispersive X-ray spectroscopy (SEM-EDX) experiments were performed to monitor the presence and proportion of phosphorus and copper at each step of the phosphate loading and copper adsorption processes. These results demonstrate the feasibility of synthesizing a rechargeable polymer material with functional molded cavities with phosphate groups capable of adsorbing copper ions. Finally, this investigation represents the first approach to new materials with a rechargeable ligand system for the adsorption of heavy metals. Full article

Aims: Treatment of higher-risk myelodysplastic syndromes (HR-MDS) with azacytidine (AZA) exerts significant effects on the epigenome, primarily through DNA demethylation and reactivation of epigenetically silenced genes. Beyond this established mechanism, molecular AZA-linked effects are increasingly being recognized. Materials and methods: Liquid chromatography combined with mass spectrometry (LC-MS/MS) was employed for the accurate assessment of various RNA and DNA modifications pre- and post-AZA treatment of an HR-MDS cohort (N = 8). Mapping of the AZA treatment-responsive regulatory pathways was performed by miRNA-next generation sequencing (NGS), followed by a multi-layered bioinformatic pipeline, integrating miRNA differential expression, gene set enrichment, and network analyses. The precise number of mitochondrial (mt)DNA copies pre- and post-AZA was evaluated by a digital PCR assay. Results: Cell pathways affected by miRNA differential expression patterns pre- and post-AZA treatment discriminated the clinical phenotypes of Responders against Non-Responders to therapy. Intracellular RNA modifications: N6-methyladenosine (m6A), 5-methylcytidine (m5C), N1-methyladenosine (m1A), 2′-O-methylguanosine (Gm) and adenosine-to-inosine (A → I) editing were evaluated for their potential impact in treatment response. Nuclear DNA/mtDNA methylation profiles and mtDNA copy number reduction manifested the mitochondrial features affected by AZA. Our results suggest that neoplastic HSPCs in HR-MDS Responders to AZA adapt by normalizing glycolytic metabolism and enhancing ribosomal activity. The observed reduction of mtDNA content can be associated with improved survival and suppression of malignant progression. Non-Responders, despite experiencing mtDNA depletion, seem unable to coordinate such metabolic reprogramming and remain disadvantaged to AZA therapy. Full article

Background and Objectives: p16 immunohistochemistry (IHC) is widely used as a surrogate marker for high-risk human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma. Diagnostic reliability in laryngeal squamous cell carcinoma (LSCC) is still up for debate, particularly because HPV DNA detection, p16 overexpression, and transcriptionally active HPV infection may be discordant at this anatomical site. This systematic review aimed to assess the diagnostic performance of p16 IHC as a surrogate marker for high-risk HPV status in primary invasive LSCC. Materials and Methods: A systematic review was conducted in accordance with PRISMA principles and prospectively registered in PROSPERO. PubMed, Scopus, and Web of Science, and citation searches were used to identify studies reporting paired p16 IHC and tumour-based molecular HPV testing in invasive LSCC. Eligible HPV reference standards included HPV DNA PCR/genotyping, DNA in situ hybridization, RNA in situ hybridization, and E6/E7 mRNA detection. Data were synthesized narratively because of substantial heterogeneity in p16 thresholds, HPV assays, and study populations. Results: Fourteen studies were included. p16 positivity thresholds varied widely, ranging from ≥30% moderate/strong staining to ≥70–75% diffuse nuclear and cytoplasmic staining. HPV reference standards also differed substantially across studies. Overall, p16 IHC showed inconsistent concordance with molecular HPV testing. Studies using RNA-based reference standards showed that transcriptionally active HPV was uncommon in LSCC and that p16-positive tumours often lacked evidence of active HPV transcription. Conclusions: p16 IHC should not be used as a standalone surrogate marker for high-risk HPV-driven carcinogenesis in invasive LSCC. When HPV attribution is clinically or analytically important, p16-positive cases should be confirmed using HPV-specific molecular testing, preferably RNA-based assays. Future prospective studies using standardized p16 protocols and transcriptionally active HPV reference standards are needed. Full article

Background and Objectives: Acute cerebral ischemia is characterized by excessive oxidative stress and impaired antioxidant defense mechanisms, in which the nuclear factor erythroid 2–related factor 2 (Nrf2)–Kelch-like ECH-associated protein 1 (Keap1) signaling pathway plays a pivotal regulatory role. This study aimed to investigate serum levels of Nrf2–Keap1 pathway components and associated oxidative stress biomarkers in patients with acute ischemic stroke. Materials and Methods: Eighty-eight patients diagnosed with ischemic stroke who presented within 24 h of the onset of neurological deficit and met the inclusion criteria, along with 72 healthy control subjects without a history of acute ischemic stroke, were included in the study. Serum levels of Nrf2, Keap1, glycogen synthase kinase-3β (GSK-3β), heme oxygenase-1 (HO-1), glutathione (GSH), and 4-hydroxynonenal (4-HNE) were quantified using enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the biomarkers. Results: Compared with controls, patients exhibited significantly reduced Nrf2 levels and markedly elevated Keap1 and 4-HNE levels. HO-1 and GSH concentrations were also significantly increased in the patient group, whereas GSK-3β levels did not differ significantly between groups. ROC analysis demonstrated that 4-HNE and Nrf2 possessed the highest discriminative capacity for acute ischemic stroke. Conclusions: These findings suggest that acute cerebral ischemia is associated with dysregulation of the Nrf2–Keap1 axis accompanied by enhanced lipid peroxidation and oxidative burden. Although increased HO-1 and GSH levels may reflect a compensatory antioxidant response, elevated 4-HNE levels indicate persistent oxidative injury. Full article

Silicon carbide (SiC), a third-generation wide-bandgap semiconductor, demonstrates prominent application advantages for extreme-environment sensing scenarios including deep-space exploration, nuclear reactor monitoring, and fusion device diagnosis, which benefit from its excellent radiation resistance, high-temperature stability, and chemical inertness. This review systematically investigates the action mechanisms of different radiation environments on the electrical and mechanical properties of SiC-based sensors, with emphasis on the regulatory effects of radiation-induced defects on key sensing parameters, including piezoresistive properties, charge-collection efficiency, leakage current, and sensitivity. In addition, this paper discusses the response behavior and research progress of SiC sensors applied in mixed radiation fields. Existing research confirms that although high-fluence radiation can induce lattice defects and further result in the degradation of SiC sensor sensing performance, SiC still retains remarkable advantages in intrinsic radiation resistance. The sensing reliability of SiC in extreme environments can be further improved via device-structure optimization and material-modification strategies. This review is expected to provide a theoretical reference for the development and design of SiC sensors applied in advanced nuclear energy, aerospace, and nuclear medicine fields. Full article

Nuclear infrastructure requires reliable gamma radiation shielding, for which heavyweight concrete offers a practical, structural solution. Conventional concrete provides poor gamma shielding and heat durability, demanding a denser alternative. Prior studies show that magnetite enhances attenuation and strength, while dolomite improves thermal/mechanical stability, yet findings are dispersed across materials and test conditions. Hybrid magnetite–dolomite concrete requires systematic evaluation for simultaneous optimal gamma shielding and mechanical performance under nuclear conditions. Two mixes were produced by partial replacement of coarse aggregate (Mix 1: 50% magnetite, 25% dolomite; Mix 2: 25% magnetite, 50% dolomite), casted and cured per standard practice with compressive strength measured at 7 and 28 days. Gamma attenuation was quantified using Cs-137 and Co-60. Mix 1 achieved 78.78% attenuation for Cs-137 and 76.86% for Co-60, while Mix 2 reached 77.65% and 74.68%, respectively. At 28 days, peak compressive strengths were 25.8 MPa (magnetite), 22.6 MPa (dolomite), and 20.6 MPa (control), with pre-peak energy capacity ranking as follows: magnetite > dolomite > control. Magnetite increased strength and attenuation but sharpened post-peak softening, whereas dolomite enhanced deformability and energy dissipation with minimal loss in shielding. Hybrid concrete satisfied shielding and strength targets and outperformed conventional concrete, with a magnetite-forward blend offering the best overall protection. Full article

TPEN (N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine) is a ligand containing six nitrogen donors. It is characterized by high structural flexibility, enabling the coordination of metals with various ionic radii and coordination numbers. It is an advanced metal chelator that demonstrates high selectivity, particularly towards “soft” and “medium” metal ions, and has a wide range of applications, from coordination chemistry, materials engineering, and nuclear energy to innovations in medicine. TPEN can cross cell membranes freely, which is important in cell biology. However, its presence is not neutral for healthy cells and can lead to apoptosis by depleting essential metals such as zinc, iron, and copper. Targeted delivery systems are therefore essential. This can be achieved, for example, by using nanoparticles that release TPEN upon ultrasound. This review systematizes the understanding of TPEN complexes. Methods for the coordination of various d-, p-, and f-block metals are presented, as well as the properties of these complexes, which are crucial to understanding the mechanisms of reaction with TPEN. This ligand may find applications both as a diagnostic tool (in sensors) and as a therapeutic tool (by inducing cancer cell death). This work also demonstrates the need to design new and more effective TPEN analogs that overcome problems with solubility and stability in acids. Full article