Search Results (1,376)

The influence of nitrate (NO₃⁻) concentration on the corrosion resistance of the Inconel 625 (superalloy) was investigated. The surface of Inconel 625 was chemically modified by oxidation in an alkaline sodium nitrate(V) solution. The surface and microstructure of specimens were observed by a scanning electron microscope (SEM). The mechanical properties of Inconel 625 were characterized by microhardness (HV) measurements. The corrosion tests of materials were carried out by using the electrochemical method in the acidic chloride solution. The adsorption of the (Me_mO_n)_ads layer effectively separates the Inconel 625 surface from contact with the aggressive corrosive environment. The microhardness (HV10) value increased (about 13%) with the increase in nitrate concentration. A more-than-five-times-lower corrosion rate (CW) value was obtained for the Inconel 625 sample, whose surface was modified in an alkaline solution with the highest NO₃⁻ concentration. Chemical modification improves the structure and surface topography of the superalloy. After exposing Inconel 625 to an oxidizing environment (1.00 M NO₃⁻), the surface coverage degree (SC) was 80%. Full article

Current research on automotive supply networks predominantly examines single-type entities connected through one relationship type, resulting in oversimplified, single-layer network structures. This conventional approach fails to capture the complex interdependencies that exist among mineral resources, intermediate components, and finished products throughout the automotive industry. To overcome these analytical limitations, this study implements a multilayer network framework for examining global automotive supply chains spanning 2017 to 2023. The research particularly emphasizes the identification of critical risk sources through both static and dynamic analytical perspectives. The static analysis employs multilayer degree and strength centralities to illuminate the pivotal roles that countries such as China, the United States, and Germany play within these multilayer automotive supply networks. Conversely, the dynamic risk propagation model uncovers significant cascade effects; a disruption in a major upstream supplier can propagate through intermediary layers, ultimately impacting over 85% of countries in the finished automotive layer within a short temporal threshold. Furthermore, this study investigates how individual nations’ anti-risk capabilities influence the overall resilience of multilayer automotive supply networks. These insights offer valuable guidance for policymakers, enabling strategic topological modifications during disruption events and enhanced protection of the most vulnerable risk sources. Full article

Drug-resistant bacteria cause millions of global infections each year, and the development of alternative antimicrobial drugs has become a serious undertaking. Currently, peptides with antimicrobial activity represent potential candidates for new antibiotic discovery as they are less likely to cause drug resistance in bacteria. In this study, bifunctional peptides with potent trypsin-inhibitory activity and antimicrobial activity were obtained by rational computation-based structural modifications to a novel Bowman–Birk-type inhibitor (BBI) peptide. The analogues not only displayed potent bacterial killing ability against two drug-resistant bacteria strains of E. coli but also an excellent safety profile, as assessed by low haemolytic activity and low anti-proliferation activity on HaCaT cells. Throughout the molecular dynamics simulations, the peptides exhibited stable adsorption onto the mixed POPE/POPG membrane; most amino acid residues of the AMPs remained bound to the membrane surface, with a few amino acid residues partially penetrating the membrane interior. This showed that the electrostatic interactions were the dominant driving force mediating the peptide–membrane associations. In addition, the tested peptides displayed a degree of stability in the presence of salt ions, serum, and trypsin. These modified peptides thus possess potential as clinical antibacterial agents, and the strategies used in structural modification may also provide a different path to developing new antimicrobial peptides. Full article

This study investigated the effect of superheated steam (SS) assisted glycosylation modification on the flavor profile of oyster peptides (OP), and explored the correlation between key flavor compounds and glycosylation degree using Gas Chromatography–Ion Mobility Spectrometry (GC-IMS) and nano-scale Liquid Chromatography coupled with High-Resolution Mass Spectrometry (nano-LC/HRMS). The results indicated that SS treatment accelerated the glycosylation process, reduced free amino groups level, and distinguished their unique flavor through E-nose. GC-IMS analysis detected 64 signal peaks including 13 aldehydes, 6 ketones, 7 esters, 6 alcohols, 2 acids, 2 furans and 5 other substances. And it was revealed that SS-mediated glycosylation treatment reduced the levels of fishy odorants like Heptanal and Nonanal, while promoting the pleasant-smelling alcohols and esters. In addition, Pearson correlation showed a positive correlation between excessive glycation and the increase in aldehydes, which might cause the recurrence of undesirable fishy notes. Further nano-LC/HRMS analysis revealed that arginine and lysine acted as the main sites for glycosylation modification. Notably, glycosylated peptides such as KAFGHENEALVRK, DSRAATSPGELGVTIEGPKE, generated by mild SS treatment could convert into ketones and pyrazines in subsequent reactions, thereby contributing to overall sensory enhancement. In conclusion, SS treatment at 110 °C for 1 min significantly improved the flavor quality of OP and sustains improvement in subsequent stages, providing theoretical support for flavor optimization of oyster peptides. Full article

This study presents an analytical methodology for evaluating the influence of hull design parameters on the controllability and manoeuvrability of ships equipped with integrated electric propulsion systems. Unlike traditional approaches that examine the hull and propulsion plant independently, the proposed method employs a generalized model of transient modes within the propulsion complex, enabling the coupled interaction among the hull, propulsion units, electric motors, and the electrical power system to be captured during manoeuvring. Active experimental design and regression modelling are applied to construct controllability diagrams, identify the most influential dimensionless parameters, and reduce computational effort. The methodology is used to assess the effect of hull elongation (0.08–0.16 L) with curvature variation limited to 6%. The results show that this degree of elongation has minimal impact on turning performance and course-keeping stability, confirming the feasibility of such design modifications. The proposed approach provides an effective tool for early-stage design and modernization of electric ships and supports decision-making in ship behaviour prediction and traffic management. Full article

Phosphodiesterase 4 (PDE4) is a key enzyme responsible for the hydrolysis of cyclic adenosine monophosphate (cAMP), thereby regulating essential signaling pathways involved in inflammation and immune modulation. Structural studies have demonstrated a high degree of conservation within the catalytic domains of PDE4 isoforms, accompanied by subtle conformational variations that underlie their selectivity and tissue-specific distribution. Elucidating these structural features has been instrumental in guiding the rational design of PDE4 inhibitors. Although synthetic PDE4 inhibitors such as roflumilast and apremilast exhibit significant therapeutic efficacy, their clinical application is often limited by dose-dependent adverse effects. These effects primarily arise from insufficient isoform selectivity, as current inhibitors tend to target multiple PDE4 subtypes indiscriminately, resulting in off-target pharmacological actions and reduced tolerability. In contrast, natural products—including flavonoids, terpenoids, and related polyphenolic compounds such as curcumin, α-mangostin, and their derivatives—have emerged as promising molecular scaffolds. Their lower toxicity, favorable biocompatibility, and structural diversity enable fine-tuning of potency and selectivity through rational modification. Integrating structural insights derived from crystallographic and computational studies with the optimization of natural compounds offers a sustainable and effective strategy for the development of safer, isoform-selective PDE4-targeted therapies. Full article

Recent studies show that titanium (Ti)-based alloys combine established mechanical strength, corrosion resistance, and biocompatibility with emerging electrical and electrochemical properties relevant to bioelectronics. The main goal of the present manuscript is to give a wide-ranging overview on the use of Ti-alloys in electronics and biomedicine, focusing on a comprehensive analysis and synthesis of the existing literature to identify gaps and future directions. Concurrently, the identification of possible correlations between the effects of the manufacturing process, alloying elements, and other degrees of freedom influencing the material characteristics are put in evidence, aiming to establish a global view on efficient interdisciplinary efforts to realize high-added-value smart devices useful in the field of biomedicine, such as, for example, implantable apparatuses. This review mostly summarizes advances in surface modification approaches—including anodization, conductive coatings, and nanostructuring that improve conductivity while maintaining biological compatibility. Trends in applications demonstrate how these alloys support smart implants, biosensors, and neural interfaces by enabling reliable signal transmission and long-term integration with tissue. Key challenges remain in balancing electrical performance with biological response and in scaling laboratory modifications for clinical use. Perspectives for future work include optimizing alloy composition, refining surface treatments, and developing multifunctional designs that integrate mechanical, biological, and electronic requirements. Together, these directions highlight the potential of titanium alloys to serve as foundational materials for next-generation bioelectronic medical technologies. Full article

Fenestrations of mammalian skull bones are rare and poorly understood, particularly within the parietal bone. In bats—a group characterised by advanced sensory specialisation and echolocation—superficial modifications of the cranial vault may have functional significance, yet their occurrence and organisation remain insufficiently documented. In this study, we describe an exceptional fenestrated complex in the posterolateral parietal bone of Plecotus auritus, comprising structural elements not previously recorded within Vespertilionidae. The aim of the study was to characterise in detail the morphology, topography, and variability of the surface structure termed Fenestras Elisabeth (nova structura), with particular emphasis on its relationship with the auditory region and its potential biomechanical–acoustic significance. The material consisted of ten skulls of P. auritus, examined using micro-CT scanning, 3D reconstruction, and qualitative analysis of fenestrated structures and their topographic relationships. Within the posterolateral parietal region, we identified an extensive and repeatable fenestrated complex comprising numerous fenestrae parietales Elisabeth, paired fenestrula Elisabeth, a central depression (recessus acousticus parietalis), and a bordering fissure (fissura occipitalis mastoidea, nova structura topographica). The complex exhibited a stable spatial organisation despite individual variation in the number and shape of the openings. All fenestrations were confined to the posterolateral zone, and the contact between the fenestrae and the fissura occipitalis mastoidea represented a diagnostic feature. Our analysis suggests that the Fenestras Elisabeth complex may be associated with combined biomechanical and acoustic constraints: (1) a biomechanical role—reducing strain in the parietal lamina during movements of the extremely mobile and elongated pinnae; and (2) an acoustic role—modulating micro-vibrations transmitted to the inner-ear structures. Individual variability and lateral asymmetry of fenestration patterns indicate a high degree of adaptive plasticity in this region of the skull. This study provides the first documentation of a large, structurally organised parietal-bone fenestration complex in Plecotus auritus, expanding current knowledge of bat cranial morphology and suggesting a likely functional significance for these previously unknown bony structures. Full article

Remediating cadmium (Cd) contamination in aquatic and terrestrial environments has become an urgent environmental priority. Biochar has been widely employed for heavy metal removal due to its wide availability, strong adsorption capacity, and potential for recycling agricultural waste. In this study, samples of alkali–Fe-modified biochar (Fe@NaOH-SBC, Fe@NaOH-HBC, and Fe@NaOH-MBC) were prepared from agricultural wastes (ginger straw, Sichuan pepper branches, and kiwi leaves) through NaOH and FeCl₃·6H₂O modification. A comprehensive characterization confirmed that the alkali–Fe-modified biochar exhibits a higher specific surface area, richer functional groups, and successful incorporation of the iron oxides Fe₃O₄ and α-FeOOH. The fitting parameter qmax from the Langmuir model indicates that the alkali–Fe modification of carbon significantly enhanced its maximum capacity for Cd²⁺ adsorption. Furthermore, a synergistic effect was observed between iron oxide loading and alkali modification, outperforming alkali modification alone. Furthermore, a 30-day soil incubation experiment revealed that the application of alkali–Fe-modified biochar significantly increased soil pH, SOM, and CEC while reducing the available cadmium content by 13.34–33.94%. The treatment also facilitated the transformation of highly bioavailable cadmium species into more stable, less bioavailable forms, thereby mitigating their potential entry into the food chain and the associated human health risks. Moreover, short-term spinach seed germination experiments confirmed that treatments with varying additions of alkali–Fe-modified biochar mitigated the inhibition of seed physiological processes by high concentrations of available cadmium to varying degrees. Overall, this study provides a sustainable and effective strategy for utilizing agricultural waste in the remediation of cadmium-contaminated water and soil systems. Full article

Environmentally friendly sucrose-based poly(ester-urethane)s were synthesized and characterized, and their stability and degradation behavior were assessed under three different aging conditions: thermal, ultraviolet (UV), and hydrolytic treatment. The specimens underwent thermal treatment in both hot and cold climates to simulate a temperate continental climate. The samples were thoroughly characterized to assess chemical and structural changes (FT-IR, TGA, and DSC) and surface modifications (contact angle measurements and AFM and SEM analyses), providing insights into surface morphology and wettability alterations. Mechanical testing was also performed to evaluate the retention rate of the strength and the elongation after the aging process. The results showed that the introduction of sucrose into the main chain of the polyurethanes protected the ester and urethane groups from environmental degradation. The best stability in all three degradation environments was achieved by PCL-poly(ester urethane) due to its higher degree of crystallinity. PCL-based polyurethane exhibited a fracture strength retention rate exceeding 85% under all aging conditions, while the weight ratio remained practically unchanged after hydrolytic degradation. Thus, the obtained polyurethanes may support the advancement of sustainable, eco-friendly materials for future industrial applications. Full article

As a cutting-edge technology in the field of cement-based materials, early carbonation curing enables industrial carbon sequestration and functional modification, and the optimization of process parameters is the key to advancing the development of this technology. This paper reviews the mechanism of action and influencing factors of early carbonation curing (including moisture content, carbon dioxide concentration, pre-hydration degree, etc.), its effects on the mechanical properties and durability of materials, as well as the resulting changes in microstructure. Meanwhile, this review also covers content such as the hydration–carbonation coupling mechanism, mentions the relevant conditions of carbonation products and microstructure, analyzes the performance enhancement of the interfacial transition zone (ITZ), and provides relevant support for the low-carbon development of cement-based materials by combining the application practice of prefabricated components and the comparison of technical routes. Although early carbonation can significantly improve material properties and optimize microstructure, current research still has shortcomings: the exploration of mineral carbonation–hydration activity, microstructure evolution law, and product combination mechanism is relatively insufficient, and the understanding of carbonation–hydration coupling kinetics is still not in-depth enough, all of which are areas requiring further research in the future. Full article

Hydroxyl-terminated polybutadiene (HTPB) is widely used in polyurethane binders, adhesives, and elastomers, but its low polarity and unsaturated backbone limit adhesion and long-term stability. Epoxidation presents a promising approach to addressing these limitations. However, most prior studies have focused on high-cis polybutadiene (PB), and systematic tuning of epoxidation in industrial low-cis HTPB has not been thoroughly examined. In this work, the epoxidation conversion of low-cis HTPB was systematically controlled by varying the equivalent amount of 3-chloroperbenzoic acid (m-CPBA). Conversion was governed solely by oxidant stoichiometry, while reaction time, concentration, and temperature had minimal effect, consistent with rapid, mixing-controlled epoxidation. Selective modification of 1,4-cis and 1,4-trans units enabled direct evaluation of how epoxidation degree influences polyurethane network formation and performance. Polyurethanes derived from epoxidized HTPB (EHTPB-PU) exhibited a clear correlation between epoxidation degree and network formation. Mechanical, adhesion, and chemical-resistance measurements revealed optimal performance at 10% epoxidation, where polarity and network compactness are effectively balanced. At this level, polyurethanes showed enhanced tensile strength, broad substrate adhesion, and increased resistance to acidic, basic, polar, and nonpolar environments, along with reduced water uptake. These results identify moderate epoxidation as a practical and efficient strategy for improving HTPB-based polyurethane materials. Full article

Farmland soil water-soluble organic carbon (WSOC), serving as a labile carbon substrate for microbial utilization, demonstrates pronounced sensitivity to land-use modifications and agricultural management practices. This study systematically investigated the impacts of long-term straw incorporation frequencies—including annual (S-1), biennial (S-2), and triennial (S-3) return patterns—on WSOC distribution across 0–20 cm and 20–40 cm soil profiles. Through the integration of three-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis (PARAFAC), we elucidated structural characteristics and humification dynamics associated with different incorporation regimes. The results showed a depth-dependent WSOC distribution pattern with higher concentrations in surface soils (0–20 cm: 261.2–368.9 mg/kg) compared to subsurface layers (20-40 cm: 261.8–294 mg/kg). Straw incorporation significantly increased WSOC content in the 0–20 cm of 16.9%~21.7% and 20–40 cm soil layers of 6.2%~12.3%. Biennial return had the lowest WSOC/SOC ratio, indicating enhanced stability of the soil organic carbon pool. Spectral indices—including the fluorescence index (FI, 1.59~1.69), biological index (BIX, 0.90~0.95), and humification index (HIX, 0.64~0.74)—collectively indicated that WSOC predominantly consisted of microbially processed organic matter with a low degree of humification. PARAFAC modeling resolved two fluorescent components: C1 (humic acid-like substances, 47.4–50.4%), C2 (soluble microbial metabolites, 49.6–52.6%). This systematic investigation provides mechanistic insights into how straw management temporality regulates both quantity and quality of labile carbon pools in agricultural ecosystems. Full article

Granular copper oxide nanoparticles (CopOx NPs), synthesized via laser ablation (100 nm, ζ-potential +30 mV), were introduced into photolithographic polymethyl methacrylate (PMMA) resin at concentrations of 0.001–0.1%. The resulting composite material enables the fabrication of high-resolution (up to 50 μm) parts with a high degree of surface quality after polishing using the MSLA method. CopOx NPs increased the degree of resin polymerization (decrease by almost 4× in unpolymerized components at 0.1% CopOx NPs) and induced the in situ formation of self-organized periodic structures visible under a modulation interference microscope. The composite samples exhibit pronounced oxidative activity: they intensify the generation of hydrogen peroxide and hydroxyl radicals and cause the oxidative modification of biomolecules (formation of 8-oxoguanine in DNA and long-lived reactive forms of proteins). A key property of the materials is their selective biological activity. While lacking cytotoxicity for human fibroblasts, they exhibit a strong antibacterial effect against E. coli, leading to cell death within 24 h. Thus, the developed composite photolithographic resin combines improved technological characteristics (high printing resolution, degree of polymerization) with functional properties (selective antibacterial activity) and holds promise for application in biomedicine, as well as in the food and agricultural industries. Full article

This review examines the safety and clinical efficacy of mesenchymal stem/stromal cells (MSCs)-based therapies in patients with spinal cord injury (SCI). The analysis covers 26 clinical studies conducted on patients with varying degrees of the post-SCI neurological deficit. The review highlights the methodology of trials, the source of MSCs, the dosage of cells administered, transplantation methods, patient inclusion criteria, and the methods of evaluating the effectiveness of the therapy. MSC transplantation in SCI was safe and feasible in all the studies summarized in our review. All studies conducted have demonstrated varying degrees of patient improvement and reduction in the severity of neurological deficits. However, further controlled randomized studies on larger numbers of patients are needed to better evaluate the therapeutic efficacy of MS transplantation. The prospects of the enhancement of the efficacy of the SCI cell therapy with MSCs, including their transplantation with other types of stem cells, administration of MSC-derived exosomes, genetic modification of MSCs, use of the MSC- and other-stem-cell-based tissue-engineered scaffolds, and combination of cell therapy with neuromodulation, are discussed. Full article