Search Results (10,391)

This study investigates the strength and microstructural evolution of SRX-stabilized aeolian sand–gravel mixtures for flexible base applications in desert roads. CBR, UPS (uniaxial penetration strength), and compressive resilient modulus tests were conducted under varying SRX dosages (0.4–1.0%) and aeolian sand contents (30–50%). The results show that increasing the SRX dosage significantly improves all three indices, with the 0.5% SRX and 30% aeolian sand mixture yielding the CBR (385.89%) and UPS (0.938 MPa) and achieving a compressive resilient modulus that meets the requirements for graded aggregate base layers. XRD FTIR and SEM–EDS analyses reveal that the SRX enhances material structure primarily through physical mechanisms, forming dense films and bonding networks without inducing significant chemical reactions. Extended curing improves structural integrity, while excessive aeolian sand reduces compactness. SRX-stabilized aeolian sand gravel is a viable base and subbase material for desert highways. Full article

Constructing heterojunction photocatalysts with efficient interfacial charge transfer is critical for solar-driven hydrogen evolution. In this study, a highly dispersed MoS₂/g-C₃N₄ composite was successfully synthesized via a stirring-assisted hydrothermal in situ growth strategy. The introduction of stirring during synthesis significantly enhanced the uniform dispersion of MoS₂ nanosheets and exposed abundant edge sites, leading to well-integrated heterojunctions with enhanced interfacial contact. Comprehensive structural and photoelectronic characterizations (XRD, SEM, TEM, EDS mapping, UV–Vis, TRPL, EIS, EPR) confirmed that the composite exhibited improved visible-light absorption, accelerated charge separation, and suppressed recombination. Under simulated solar irradiation with triethanolamine (TEOA) as a sacrificial agent, the optimized 24% MoS₂/g-C₃N₄-S catalyst achieved a high hydrogen evolution rate of 14.33 mmol·g⁻¹·h⁻¹ at a catalyst loading of 3.2 mg, significantly outperforming the unstirred and pristine components, and demonstrating excellent cycling stability. Mechanistic studies revealed that the performance enhancement is attributed to the synergistic effects of Type-II heterojunction formation and edge-site-rich MoS₂ co-catalysis. This work provides a scalable approach for non-noble metal interface engineering and offers insight into the design of efficient and durable photocatalysts for solar hydrogen production. Full article

During the roasting, leaching, and electrodeposition of zinc ores, lead–silver residues are produced. These residues contain valuable metals (Pb, Zn, and Ag) and toxic metals (Cd and As). In this study, a pyrometallurgical process is proposed for treating Pb-Ag residues, consisting of drying, roasting, and reduction steps to recover valuable metals, such as silver in a metallic Pb phase, while converting the waste into an environmentally friendly slag. First, the Pb-Ag residue is dried at 100 °C, then roasted at 700 °C, and finally reduced at a high temperature, with Na₂CO₃ as a flux and CaSi as a reducing agent, rather than carbon-based reducing agents (carbon or carbon monoxide), to minimize greenhouse gas production. The effects of the reduction temperature and the mass of the reducing agent were investigated on a laboratory scale. The metallic phase and slag obtained in the reduction step were characterized by their chemical composition and mineralogy via chemical analysis, X-ray diffraction, and SEM-EDS. The results showed that silver and lead formed a metallic phase, and that silver content decreased from 1700 ppm in the Pb-Ag residue to 32 ppm in the final slag at 1300 °C. The Pb-Ag residue and final slag were leached with an aqueous acetic acid solution to evaluate their chemical stability. Full article

Objectives: Few studies have reported in vivo measurements of electron density (ED) and effective atomic number (Z_eff) in normal brain tissue. To address this gap, dual-energy computed tomography (DECT)-derived ED and Z_eff maps were used to characterize normal-appearing adult brain tissues, evaluate age-related changes, and investigate correlations with myelin partial volume (V_my) from synthetic magnetic resonance imaging (MRI). Materials and Methods: Thirty patients were retrospectively analyzed. The conventional computed tomography (CT) value (CT_conv), ED, Z_eff, and V_my were measured in the normal-appearing gray matter (GM) and white matter (WM) regions of interest. V_my and DECT-derived parameters were compared between WM and GM. Correlations between V_my and DECT parameters and between age and DECT parameters were analyzed. Results: V_my was significantly greater in WM than in GM, whereas CT_conv, ED, and Z_eff were significantly lower in WM than in GM (all p < 0.001). Z_eff exhibited a stronger negative correlation with V_my (ρ = −0.756) than CT_conv (ρ = −0.705) or ED (ρ = −0.491). ED exhibited weak to moderate negative correlations with age in nine of the 14 regions. In contrast, Z_eff exhibited weak to moderate positive correlations with age in nine of the 14 regions. CT_conv exhibited negligible to insignificant correlations with age: Conclusions: This study revealed distinct GM–WM differences in ED and Z_eff along with opposing age-related changes in these quantities. Therefore, myelin may have substantially contributed to the lower Z_eff observed in WM, which underlies the GM–WM contrast observed on non-contrast-enhanced CT. Full article

This research explores the effect of a composite support of SiO₂ and Al₂O₃ with Fe and Co incorporated as catalysts for Fischer–Tropsch synthesis (FTS) using a 3D-printed stainless steel (SS) microchannel microreactor. Two mesoporous catalysts, FeCo/SiO₂Al₂O₃ and Co/SiO₂Al₂O₃, were synthesized via a one-pot (OP) method and extensively characterized using N₂ physisorption, XRD, SEM, TEM, H₂-TPR, TGA-DSC, FTIR, and XPS. H₂-TPR results revealed that the synthesis method significantly affected the reducibility of metal oxides, thereby influencing the formation of active FTS sites. SEM-EDS and TEM further revealed a well-defined hexagonal matrix with a porous surface morphology and uniform metal ion distribution. FTS reactions, carried out in the 200–350 °C temperature range at 20 bar with a H₂/CO molar ratio of 2:1, exhibited the highest activity for FeCo/SiO₂Al₂O₃, with up to 80% CO conversion. Long-term stability was evaluated by monitoring the catalyst performance for 30 h on stream at 320 °C under identical reaction conditions. The catalyst was initially active for the methanation reaction for up to 15 h, after which the selectivity for CH₄ declined. Correspondingly, the C₄⁺ selectivity increased after 15 h of time-on-stream, indicating a shift in the product distribution toward longer-chain hydrocarbons. This trend suggests that the catalyst undergoes gradual activation or restructuring under reaction conditions, which enhances chain growth over time. The increase in C₄⁺ products may be attributed to the stabilization of the active sites and suppression of methane or light hydrocarbon formation. Full article

The objectives of this study were to determine the dose effect/s of glucose (G) and fructose (F) at different energy densities (ED) of diets on feed intake, body and organ weights, chemical composition of liver, feed conversion, and metabolomic indices (enzymes and hormones). Methods: Seventy-two 10-week-old male Wistar SPF rats were divided into 9 dietary groups and housed individually in metabolic cages. The control group was on a carbohydrate-free high lard diet (L), and for the other 8 treatment groups, the L content of the control diet was gradually replaced by G or F to decrease the dietary ED, in such a way that the nutrients (protein, minerals and vitamins) to energy ratio of the feeds remained constant. These experimental diets were fed to rats for 28 days. Feed intake and body weight were measured twice weekly. On the 28th day of the experiment, the rats were euthanized, and blood and organ samples were collected for further tests. Results and conclusions: The effects of F and G on twenty-six parameters were measured at different EDs of diets. Significant specific F effects (SFE) over the rats on G diets were found in case of feed intake (statistics with pooled data of feed intake (Fi) showed ~7% more feed intake of F rats: 10.8, 6.4, 9.5 and 2.0% at 5.28, 4.70, 4.23 and 3.85 kcal/g ED, respectively); body weight gain (the relation is polynomial; 8.0, 10.3, 0.1, and −10.2% at 5.28, 4.70, 4.23, and 3.85 kcal/g ED; it related to the weight change of viscera: liver, kidney and RWAT); liver fat (3.98, 21.42, 49.20 and 11.05% at 5.28, 4.70, 4.23, and 3.85 kcal/g ED, respectively); serum triglyceride (the relation is polynomial; 63.2, 88.1, 79.2 and 42.6% at 5.28, 4.73, 4.23, and 3.85 kcal/g ED, respectively); serum glucagon (−1.2, 380.2, 248.3 and 74.7% at 5.28, 4.70, 4.23, and 3.85 kcal/g ED, respectively), and serum leptin (9.59, 30.53, 72.64, and −46.49% at 5.28, 4.70, 4.23, and 3.85 kcal/g ED, respectively). An important conclusion is that in several cases, the effects of F and G were similar in the direction of change, but the magnitude of the effects was different. In case of feed conversion rate, there was no difference between the effect of G and F, however it is important to note that the higher the dietary energy and nutrient density, the better the feed conversion rate (FCR); The potential mechanism(s) of effect for each parameter is discussed and, where appropriate, the clinical relevance of the data compared to the known literature. Full article

Pharmaceutical contaminants such as ibuprofen are increasingly detected in water sources due to widespread use and insufficient removal by conventional treatment processes. Given its persistence and adverse effects on human health and aquatic ecosystems, efficient removal technologies are needed. This study reports the synthesis of a Mg/Al-layered double hydroxide (LDH) hybridized with carbon quantum dots (CQDs) via in situ co-precipitation to enhance adsorptive performance. The hybrid (LDH-CQD) was characterized by FTIR, XRD, DSC, TGA-DTG, SEM-EDS, BET, and pH in the point of zero charge (pH_PZC) analysis. Results indicated a marked increase in surface area (2.89 to 66.9 m²/g), a shift in surface charge behavior (pHpzc from 8.57 to 6.21), and improved porosity. Adsorption experiments using ibuprofen as a model contaminant revealed superior performance of the hybrid compared to pristine Mg/Al-LDH, with a maximum capacity of 22.13 mg·g⁻¹ (% Removal = 88.53%) at 25 ppm, and in lower concentrations (5 and 10 ppm), the hybrid showed 100% removal. Kinetic modeling followed a pseudo-second-order mechanism, and the isotherm was the SIPS model (maximum adsorption capacity = 24.150 mg.g⁻¹). These findings highlight the potential of LDH-CQD hybrid as efficient and tunable adsorbents for removing emerging pharmaceutical pollutants from aqueous media. Full article

Cobalt-based alloys such as Stellite 6 are widely applied in demanding conditions because of their good resistance to wear, erosion, and corrosion, but further improvements in erosion resistance are still required. This work analyzes the effect of adding titanium and tungsten on the structure and properties of Stellite 6 coatings produced by laser cladding, aiming to enhance their erosion resistance. Penetrant tests confirmed that the additions did not reduce coating quality, and macroscopic observations showed that appropriate process parameters allowed for defect-free coatings with strong bonding to the substrate. Microstructural studies carried out by SEM/EDS (Scanning Electron Microscopy/ Energy Dispersive Spectroscopy) and XRD (X-ray Diffraction) revealed that the reference Stellite 6 coating consisted of a cobalt-based austenitic matrix with interdendritic chromium carbides, while Ti and W additions led to the in situ formation of primary and eutectic (Ti,W)C carbides. Transmission electron microscopy showed a gradient in tungsten concentration inside the primary carbides, with progressive tungsten dissolution into the TiC lattice. Although different powder compositions had only a moderate effect on hardness, erosion tests demonstrated that the coatings with Ti and W exhibited clearly improved resistance. In particular, the in situ carbides enhanced erosion resistance at 30° impingement angles, while also maintaining high resistance under 90° impact. These findings confirm that modifying Stellite 6 with Ti and W during laser cladding is an effective way to improve its durability in erosive conditions. Full article

In this work, a unique approach was used to synthesise black coatings on aluminium alloys (AA) 6061 and 7075 for applications in the aerospace field. In detail, plasma electrolytic oxidation (PEO) technology was used, maintaining the voltage constant at a relatively low value (V_max ≤ 292 V) during the process. NaVO₃ additive was used in the silicate-based electrolyte to obtain a black colour. The coatings were characterised by SEM-EDS, XPS, XRD, VIS-NIR spectroscopy, and EIS. The presence of vanadium oxides in the PEO coatings was detected by EDS, XPS, and XRD analyses. PEO coatings on AA7075 produced with 10 g/L of NaVO₃ exhibited exceptional optical characteristics, with a solar absorptance value of 95.3% in the VIS-NIR spectrum (wavelength range of 400–2000 nm). All the coatings improved the corrosion performances of the tested AA6061 and AA7075 by two or three orders of magnitude in 3.5 wt. % aqueous NaCl. Moreover, there was no sign of delamination, cracks, or any visible changes on coatings after thermal shock, performed by cycling samples between two extreme temperatures, −196 °C and 150 °C, respectively. Full article

In order to enhance the corrosion resistance of aluminum alloys, mussel adhesive protein (MAP) was intercalated into layered double hydroxide (LDH) grown onto an Al substrate. The results from X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and energy dispersive spectroscopy (EDS) measurements all confirmed that part of the positively charged MAP can be successfully intercalated into the LDH based on the strong second reactivity. MAP is able to form complexes with the metal cations and hydroxides, leading to less positive charges on the hydroxide layers of the LDH. The intercalation results in the removal of the previously intercalated anions from the interlayer space of the LDH, which maintains the charge balance and lamellar structure. The MAP intercalated LDH film can provide effective corrosion protection to the Al substrate. Full article

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a multifunctional cytokine with therapeutic applications in oncology and neurodegenerative diseases. However, its clinical use is limited by the high cost of eukaryotic production systems. Here, we developed a cost-effective Escherichia coli-based platform for high-yield production of biologically active recombinant human GM-CSF (rhGM-CSF) using SUMO fusion technology. The engineered pET-SUMO-GM plasmid enabled expression of a 33 kDa fusion protein, accounting for 23–25% of total cellular protein, though it primarily accumulated in inclusion bodies. A multi-step purification strategy—including nickel affinity chromatography, Ulp protease cleavage, and hydrophobic chromatography—yielded >99.5% pure rhGM-CSF. In vitro functional assays demonstrated equivalent activity to the WHO international standard (ED50: 0.045 vs. 0.043 ng/mL in TF-1 cell proliferation). In vivo, the preparation significantly restored neutrophil counts (3.4-fold increase, p ≤ 0.05) in a murine cyclophosphamide-induced myelosuppression model. Our results establish a scalable, prokaryotic-based method to produce functional rhGM-CSF, overcoming solubility and folding challenges while maintaining therapeutic efficacy. This approach could facilitate broader clinical and research applications of GM-CSF, particularly in resource-limited settings. Full article

Efficient and selective separation of gallium (Ga(III)) from alkaline industrial waste streams remains a significant challenge due to the coexistence of chemically similar ions such as Al(III) and V(V). In this study, a novel ion-imprinted chitosan-based adsorbent (CS/(H-CGCS)-Ga-IIP) was synthesized via a hybrid cross-linking strategy using glutaraldehyde and siloxane-modified chitosan. The optimized material exhibited a high adsorption capacity of 106.31 mg·g⁻¹ for Ga(III) at pH 9, with fast adsorption kinetics reaching equilibrium within 60 min. Adsorption behavior followed the pseudo-second-order kinetic and Langmuir isotherm models, and thermodynamic analysis indicated a spontaneous and endothermic process. In simulated Bayer mother liquor systems, the material demonstrated outstanding selectivity and a distribution coefficient ratio k_d-Ga/k_d-Al = 146.9, highlighting its strong discrimination ability toward Ga(III). Mechanistic insights from SEM-EDS, FTIR, and XPS analyses revealed that Ga(III) adsorption occurs via electrostatic interaction, ligand coordination, and structural stabilization by the siloxane network. The material maintained good adsorption performance over three regeneration cycles, indicating potential for reuse. These findings suggest that CS/(H-CGCS)-Ga-IIP is a promising candidate for the sustainable recovery of gallium from complex alkaline waste streams such as Bayer process residues. Full article

Background: Benzodiazepine poisoning is a frequent cause of emergency department (ED) visits, often related to suicide attempts. Flumazenil is the only specific antidote, but its continuous infusion protocol remains controversial because of its uncertain outcome benefits and increased risk of adverse events. This study aimed to evaluate the effect of continuous flumazenil infusion on the time to recovery of consciousness and secondary outcomes in patients with benzodiazepine poisoning stratified by hospitalization status. Methods: A retrospective cohort study was conducted at a tertiary hospital in Seoul, Korea, including adults treated for benzodiazepine poisoning in the ED between April 2019 and March 2024. The primary outcome being the time from arrival at the ED to regaining consciousness. Multivariate regression identified independent predictors of delayed recovery. Results: Among the 370 patients, 52.4% were hospitalized. Flumazenil infusion was administered in 46.8% of the patients, more often in hospitalized patients. In this group, flumazenil infusion significantly reduced the median time to regain consciousness (13.7 vs. 19.4 h, p = 0.006) but did not affect the overall hospital stay. In nonhospitalized patients, flumazenil infusion did not shorten the awakening time or prolong the ED stay. Adverse events, mainly agitation, were more frequent with flumazenil infusion. Conclusions: Continuous infusion of flumazenil accelerates the recovery of consciousness only in hospitalized patients who are severely affected by benzodiazepine poisoning but with increased adverse events and no reduction in hospital stay. Individualized patient selection and evidence-based protocols are needed for optimal and safe antidote use. Full article

Objectives: The need for routine brain magnetic resonance imaging (MRI) for patients presenting with unilateral facial palsy in the emergency department (ED) is a subject of ongoing debate. This study aimed to evaluate the diagnostic yield of MRI in this population and to identify clinical risk factors associated with non-idiopathic causes, to inform selective imaging strategies. Methods: This single-center, retrospective study was conducted in the ED of a tertiary-care center in Korea. We analyzed adult patients (aged ≥ 18 years) who presented with facial palsy as the primary symptom between 1 January 2020 and 31 December 2022. Patients with other neurological abnormalities detected during the initial examination or those who did not undergo brain MRI were excluded. The primary outcome was the identification of positive MRI findings, defined as brain lesions (e.g., ischemic stroke, tumor, and hemorrhage) considered causally related to the facial palsy based on anatomical correlation and radiological interpretation. Patients were categorized into positive or negative MRI groups accordingly, and baseline characteristics were compared between the groups. Results: Among the 436 patients who underwent brain MRI, 13 (3.0%) showed positive findings such as brain tumors or stroke that led to diagnoses other than Bell’s palsy, while the remaining 423 (97.0%) were ultimately diagnosed with Bell’s palsy. The proportion of patients with a history of transient ischemic attack/stroke and malignancy was significantly higher in the group with non-idiopathic facial palsy (p = 0.02 and p < 0.001, respectively). Conclusions: In adults presenting to the ED with clinically isolated unilateral facial palsy and no other neurological signs, routine brain MRI had a low diagnostic yield (3%). A history of malignancy or prior TIA/stroke was associated with alternative diagnoses. A selective imaging strategy based on risk factors may improve diagnostic efficiency without compromising safety. Full article

This study investigates the synergistic effects of single- and binary-additive systems on the morphology and nucleation mechanism of Sn-Pb alloy electrodeposited coatings. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry were applied in order to obtain more information on the action mechanisms of single-additive systems (cinnamaldehyde, PEG-2000, gelatin, vanillin) and binary ones (0.1 g/L cinnamaldehyde + 0.2 g/L PEG-2000) in Sn-Pb electroplating. Results showed that the use of binary-additive systems based on cinnamaldehyde and PEG-2000 significantly improved coating quality, leading to a smooth and uniform surface, dense grains, and a near-eutectic composition (Sn 63.10 wt.%, Pb 36.90 wt.%). This was because the composite additive, through synergistic effects, exhibited the highest cathodic polarization and the largest charge transfer resistance (189.20 Ω cm²), thus inhibiting the electrodeposition process of Sn²⁺ and Pb²⁺. Chronoamperometry revealed that, unlike single additives (PEG-2000 or cinnamaldehyde), the binary-additive system promoted a transition of nucleation mode to instantaneous nucleation, accompanied by a decrease in the peak current and an extension of the corresponding time. This study provides a theoretical basis and experimental support for understanding the nucleation mode of Sn-Pb electroplating, as well as optimizing the synergistic mechanism of additives. Full article