Search Results (2,267)

This study presents a novel ratiometric fluorescent sensor based on Förster resonance energy transfer (FRET) between glutathione (GSH)-coated CdTe quantum dots (CdTe/GSH QDs) and bovine serum albumin (BSA)-coated Au nanoclusters (AuNCs/BSA) for dopamine (DA) detection. The nanoparticles were characterized using transmission electron microscopy (TEM), zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy, UV-Vis absorption and fluorescence spectroscopy. Key FRET parameters, including energy transfer efficiency (E), donor–acceptor distance (r), Förster distance (R₀), and the overlap integral (J), were determined. The interactions between the CdTe/GSH-AuNCs/BSA conjugate and DA were investigated, revealing a dual mechanism of QDs fluorescence quenching that involves both energy and electron transfer. The average lifetime values and spectral profiles of CdTe/GSH QDs, both in the absence and presence of DA, suggest a dynamic fluorescence quenching process. The variation in the ratiometric signal with increasing DA concentration demonstrated a linear response within the range of 0–250 µM, with a correlation coefficient of 0.9963 and a detection limit of 6.9 nM. This proposed nanosensor exhibited selectivity against potential interfering substances, including urea, glucose, BSA, GSH, citric acid, and metal ions such as Na⁺ and Ca²⁺. The conjugate also demonstrates excellent cytocompatibility and enhances cell proliferation in HeLa epithelial cells, making it suitable for biological applications. It was successfully employed for DA detection in urine samples, achieving recoveries ranging from 99.1% to 104.2%. The sensor is highly sensitive, selective, rapid, and cost-effective, representing a promising alternative for DA detection across various sample types. Full article

This study developed an automated multistage countercurrent extraction device and applied it to the separation and extraction of phenolic acids—including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C—from an aqueous extract of Lonicera japonica Thunb. The extraction process was optimized by systematically evaluating critical parameters such as liquid–liquid equilibrium pH, internal diameter of the tee connector, phase flow rate ratio, and the number of extraction stages. The apparent partition coefficients of all six phenolic acids increased with decreasing aqueous pH, with fitted pKa values ranging from 3.7 to 4.3. A reduction in tee diameter (0.75 mm) was found to enhance mass transfer efficiency. Increasing the flowrate of both phases (20 mL/min), the organic-to-aqueous phase ratio (4:1), and the number of extraction stages (3 stages) significantly improved both stage efficiency and overall extraction yield. Under optimized conditions, the target chlorogenic acids were efficiently enriched, with their total content increasing from 50.3 mg/g to 70.1 mg/g in the solid residue after three countercurrent stages. The automated multistage countercurrent extraction system demonstrated robust performance, suggesting promising potential for applications in the preparation of traditional Chinese medicine ingredients or as an automated sample pretreatment method in analytical workflows. This study provides a novel and green technological solution for efficient separation of complex TCM systems. Full article

The competitive adsorption between phosphorus (V) and antimony (V) may influence the release of antimony from Sb-contaminated soils. The objectives of this study were to evaluate the effect of P(V) on the adsorption–desorption behavior and transport of Sb(V) in two typical soil types. Specifically, the simultaneous adsorption, competitive interactions, and miscible displacement dynamics of P(V) and Sb(V) in these soils were investigated. Results clearly indicated that the competitive effect of P(V) on Sb(V) adsorption is more pronounced in acidic red soil than in alkaline calcareous soil. The adsorption capacity of Sb(V) decreased with increasing solution pH, leading to greater mobility of Sb(V) in both soils. P(V) was preferentially adsorbed over Sb(V) in both soil types. Sb(V) adsorption isotherms fitting by Freundlich model yielded higher coefficients of determination (R²) compared to the Langmuir model, while the Langmuir model provided a good fit to the P(V) adsorption isotherms. The total released amounts of P(V) and Sb(V) accounted for 0% and 0.4%, respectively, in red soil and 2.7% and 48.6%, respectively, in calcareous soil, relative to their adsorption capacities. The red soil exhibited remarkably strong binding affinity, with only minimal amounts of P(V) and Sb(V) released after five consecutive desorption steps. Breakthrough curves (BTCs) revealed that the presence of P(V) can promote significant Sb(V) release from the soils, which persists over an extended duration. This study on the adsorption–desorption behavior of P(V) and Sb(V) in two typical soils enhances our understanding of their mobility, fate, and associated environmental risks. In conclusion, the assessment of environmental risks from antimony-contaminated soils should take into account the competitive adsorption–desorption interactions between Sb(V) and P(V). Full article

Efficient O₂ transport through the ionomer film in cathode catalyst layers (CCLs) is a critical factor for the output performance of proton exchange membrane fuel cells (PEMFCs), yet the molecular mechanisms of gas transport in ionomers remain elusive. Herein, molecular dynamics (MDs) simulations are employed to investigate short-side-chain (SSC) and long-side-chain (LSC) perfluorosulfonic acid (PFSA) ionomers on Pt/C surfaces with the coexistence of O₂/N₂. The results reveal that the side-chain structures significantly modulate the ionomer nanostructures and gas transport. SSC ionomers form compact hydrophobic domains and more interconnected hydrophilic–hydrophobic interfaces, thereby facilitating more efficient O₂ transport pathways than LSC ionomers, particularly at low hydration (λ = 3). At high hydration (λ = 11), swelling of water domains attenuates these structural disparities and becomes the dominant factor governing gas transport. In addition, O₂ diffusion consistently exceeds that of N₂, while the diffusion coefficients of O₂, N₂ and H₃O⁺ become larger at high hydration. Collectively, these findings demonstrate the structural advantages of SSC ionomers in facilitating coupled oxygen and proton transport, offering molecular-level insights to inform the rational design of high-performance PEMFCs. Full article

Background and Objectives: Esophageal cancer (EC) remains a major global public health challenge due to its aggressiveness and poor survival rates. Therefore, this study aims to summarize the incidence, mortality, prevalence, and global burden of EC based on sex, age, and geographical divisions and to investigate the correlation of some risk factors including the Sociodemographic Index (SDI) and important health indicators to identify high-risk populations. Materials and Methods: We extracted the number and age-standardized rates (ASRs) of EC incidence, mortality, disability-adjusted life years (DALYs), and targeted risk factors for 204 countries and territories from the Global Burden of Disease 2021 study. Correlations between the ASRs of incidence, death, and DALYs and risk factors were investigated using SPSS 22 with Spearman’s correlation coefficient at a 0.05 significance level. Results: In 2021, the global age-standardized incidence rate (ASIR), death rate (ASDR), and DALY rate for EC were 6.65 (95% UI: 5.88–7.45), 6.25 (95% UI: 5.53–7.00), and 148.56 (95% UI: 131.71–166.82) per 100,000, respectively. Middle-SDI and high–middle-SDI regions showed the highest and lowest ASIR, ASDR, and DALY ASRs of EC. SDI correlated negatively with ASIR (–0.363), ASDR (–0.414), and DALY ASRs (–0.422). Male-to-female ratios for ASIR, ASDR, and DALY ASRs were 3.32, 3.37, and 3.51, respectively. As age increased, the incidence, death, and DALYs of EC also increased. East Asia recorded the highest incidence, death, and DALY values and ASRs of EC. The ASIR, ASDR, and DALY ASRs also increased with dietary risks, including the low intake of calcium, fruits, omega-6 polyunsaturated fatty acids, seafood omega-3 fatty acids, and vegetables. Conclusions: Considering the incidence, mortality, and high burden of EC in some regions, alongside the presence of modifiable risk factors, major interventions are needed to reduce these risks. Therefore, identifying high-risk areas and factors of EC, promoting lifestyle changes, and lowering the screening age could enable earlier detection and reduce the mortality of EC. Full article

The escalating demand for precious metals in high-tech industries and jewelry, combined with the depletion of their reserves, underscores the need for efficient methods of gold recovery from industrial effluents. An interpolymer system comprising industrial ion exchangers KU-2-8 (in H⁺ form) and AV-17-8 (in OH⁻ form) demonstrated strong selective sorption capacity for Au(I) ions from a simulated Au(I)/Fe(II) mixed solution. The optimal KU-2-8:AV-17-8 (3:3) system achieved a sorption efficiency of 97.0% for Au(I) ions after 48 h with a desorption efficiency of 98.0% using a thiourea/sulfuric acid solution. The distribution coefficient (K_d) for Au(I) ions reached a maximum of 3233.3 mL/g at the 3:3 ratio, with a separation coefficient (β) of 40.62, indicating exceptional selectivity over Fe(II) ions. Fourier-transform infrared (FTIR) spectroscopy revealed structural changes post-sorption, including shifts in absorption bands (e.g., from 1273.5 cm⁻¹ to 1292.9 cm⁻¹) and the appearance of new bands (e.g., at 3171.1 cm⁻¹), confirming stable ion interactions. Thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) demonstrated enhanced thermal stability post-sorption, with reduced mass loss up to 100 °C. These findings highlight the KU-2-8:AV-17-8 (3:3) interpolymer system’s high selectivity, robust sorption capacity, and efficient desorption, presenting a sustainable solution for gold recovery in hydrometallurgical applications. Full article

Background: Qishen granule (QSG) is a widely prescribed herbal formula for the treatment of chronic heart failure. The mechanisms of action of QSG have been clarified; however, the effective substances remain unclear. This lack of clarity hinders quality control and the consistency of the clinical efficacy of QSG. Methods: In the present study, an integrated strategy for an efficacy- and in vivo exposure-oriented study involving metabolite profiling, molecular docking, in vitro bioassays, and in vivo pharmacokinetics was proposed for investigating the potentially effective components of QSG. Results: In total, 101 prototypes/metabolites were preliminarily identified and characterized by UHPLC-Q TOF-MS/MS. Molecular docking of the absorbed constituents with targeted proteins suggested that 49 potential components were highly related to chronic heart failure (CHF). Then, the effectiveness of these potential compounds was verified by the oxygen glucose deprivation/re-oxygenation (OGD/R)-induced H9c2 cell model. As a result, 14 active components were screened, and their median effective concentration (EC₅₀) was calculated and utilized to generate the weight coefficient for the bioeffect of each constituent. By exploring the kinetic parameters of the active compounds in a pharmacokinetic study, the exposure levels of these pharmacologically active compounds were determined by area under the curve (AUC_0→∞) calculations. Finally, by calculating the effect–constituent index (ECI) for each compound, five key active components (cryptochlorogenic acid, chlorogenic acid, isochlorogenic acid C, salvianolic acid B, and neochlorogenic acid), which possess both pharmacological activities and higher exposure levels, were revealed to be the key effective substances of QSG. Conclusions: This study is the first to combine pharmacological activities with in vivo exposure for investigating the effective components of QSG. The identification of key active components provides a foundation for improving the quality control of QSG in clinics. The efficacy- and in vivo exposure-oriented integrated method could provide reliable references for other traditional Chinese medicines (TCMs). Full article

The olive tree has exceptional agricultural and economic importance in Mediterranean regions due to its fruit, which is used to produce olive oil. However, the olive oil industry generates a significant amount of waste, including leaves from Olea europaea L. These leaves contain a high concentration of bioactive compounds, predominantly phenolic ones, which are well known for their antioxidant properties and health benefits. Determining antioxidant capacity involves the use of different assays based on absorbance (DPPH, 2,2-diphenyl-1-picrylhydrazyl; and ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and fluorescence (ORAC, Oxygen Radical Absorbance Capacity), which require reagents and long waiting times. Therefore, having a non-destructive technique capable of providing this information would be useful. To explore this, 120 olive leaf samples were analyzed using the three antioxidant assays to quantify their total antioxidant capacity. Predictive models were successfully developed for each of the three methods, achieving coefficients of determination (R²) between 0.9 and 1 across calibration, validation, and prediction. Additionally, high residual predictive deviation (RPD) values were obtained, indicating that the models exhibit strong reliability and predictive performance. Full article

Background/Objectives: Although the U.S. Food and Drug Administration (FDA) has approved one antiviral treatment and authorized others for emergency use, there is no fully effective antiviral therapy for coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Assays detecting virus-specific immunoglobulins (Ig) or nucleic acids in large-scale epidemiological, vaccine, and drug development studies remain limited due to high costs, reagent accessibility, and cumbersome protocols. Methods: A multiplex bead-based assay was developed to simultaneously detect human IgM, IgG, and IgA antibodies against the SARS-CoV-2 spike receptor binding domain (RBD) in serum using flow cytometry. Assay performance was evaluated for sensitivity, specificity, reproducibility, and cross-reactivity and compared to another immunoassay platform. Results: The assay enabled simultaneous measurement of three antibody isotypes across 624 samples within 2 h. Intra-plate coefficients of variation (CVs) ranged from 3.16 to 6.71%, and inter-plate CVs ranged from 3.33 to 5.49%, demonstrating high reproducibility. The platform also quantified background noise from nonspecific binding, facilitating straightforward data interpretation. Conclusions: This novel, flexible multiplex bead-based assay utilizing a well-established platform provides a rapid and reproducible approach for detecting SARS-CoV-2-specific antibodies. Its high throughput capacity and low variability make it well suited for large-scale epidemiological, vaccine, and therapeutic studies. The platform’s adaptability further supports application to other infectious diseases, offering an ideal tool for broad immunological surveillance. Full article

Polyurea grease (PU) is widely used in the lubrication of heavy machinery, but it can still suffer from structural or performance degradation under extreme conditions such as high temperatures and heavy loads. This study successfully synthesized a hybrid polyurea grease (LiTFSI-PU) by incorporating lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into polyurea matrix. LiTFSI coordinates with the carbonyl groups (C=O) in the thickener molecules to form weakly Lewis acidic complex, thereby reinforcing the soap fiber network structure. As a result, LiTFSI-PU exhibits increased apparent viscosity under shear. The tribological properties of LiTFSI-PU were evaluated under both ambient and elevated temperature conditions. At a load of 200 N and 150 °C, the average coefficient of friction for the 3 wt% LiTFSI-PU formulation was 0.094, which is 32.3% lower than that of the baseline polyurea grease (PU), while the wear volume was reduced by 77.5%. XPS and FIB-STEM/EDS analyses confirmed that LiTFSI-PU forms a multicomponent protective film in situ during friction, which simultaneously shields the substrate and provides lubrication. The additive strategy proposed in this work offers novel insights for the development of high-performance lubricants suitable for extreme thermomechanical conditions. Full article

Caffeic acid (CA), 3-O-caffeoylquinic acid (3-CQA), and 5-O-caffeoylquinic acid (5-CQA) were subjected to treating stimulated mouse P815 mast cells to unravel their antiallergic potential. β-Hexosaminidase release, appearance, morphology change, cytokine secretions, and degranulation-related pathway gene expressions, including Mas-related G protein-coupled receptor, member B2 (MRGP receptor B2), and inositol 1,4,5-triphosphate receptor 2 (IP3 receptor 2), in the stimulated mast cells were measured. An ELISA was used to determine the secreted cytokines. The relative gene expression folds were analyzed with reverse transcription real-time quantitative polymerase chain reaction. Correlations between gene expressions and different parameters were analyzed using the Pearson product–moment correlation coefficient (r). The results showed that CA had a superior effect than 3-CQA and 5-CQA on reducing β-hexosaminidase release, IL-4, and IL-6 cytokine secretions by the compound 48/80 (C48/80)- and 5-hydroxymethyl-2-furaldehyde (5-HMF)-stimulated mast cells. CA increased intact mast cell numbers but reduced granule releases, evidencing that CA may soothe activated mast cells. CA reduced IP3 receptor 2 gene expression. There were positive correlations between IP3 receptor 2 gene expression and IL-4 and IL-6 cytokine secretions. Our results conclude that CA might inhibit degranulation, IL-4 and IL-6 cytokine secretions, and IP3 receptor 2 gene expression in C48/80-stimulated mouse P815 mast cells. Full article

Background and Objectives: Dyslipidemia and hyperuricemia frequently co-exist in uncontrolled type 2 diabetes mellitus (T2DM), amplifying renal and cardiovascular risk. This study aimed to develop and evaluate an optimized Renal–Metabolic Risk Score (RMRS) integrating renal and lipid parameters to identify patients with both conditions. Materials and Methods: We conducted a retrospective observational study including 304 patients with uncontrolled T2DM hospitalized at the Emergency County Hospital Oradea, Romania (2022–2023). Hyperuricemia was defined as uric acid > 6 mg/dL in females and >7 mg/dL in males; dyslipidemia was diagnosed according to standard lipid thresholds. RMRS was calculated from standardized values of urea, TG/HDL ratio, and eGFR, with variable weights derived from logistic regression coefficients. The score was normalized to a 0–100 scale. Receiver operating characteristic (ROC) analysis assessed discriminative performance; quartile analysis explored stratification ability. Results: The prevalence of dyslipidemia and hyperuricemia co-occurrence was 81.6%. RMRS was significantly higher in the co-occurrence group compared to others (median 16.9 vs. 10.0; p < 0.001). ROC analysis showed an AUC of 0.78, indicating good discrimination. Quartile analysis demonstrated a monotonic gradient in co-occurrence prevalence from 64.5% in Q1 to 96.1% in Q4. Conclusions: The Renal–metabolic Risk Score (RMRS) demonstrated moderate discriminative performance in identifying patients with uncontrolled T2DM at risk for combined hyperuricemia and dyslipidemia. Because it relies on inexpensive, routine laboratory parameters, RMRS may be particularly useful in resource-limited settings to support early risk stratification, dietary counseling, and timely referral. Further validation in larger and more diverse cohorts is required before its clinical adoption. Full article

Water-based drilling fluids (WBMs) are widely applied in petroleum engineering due to their lower cost and reduced environmental impact compared to oil-based muds. However, their performance is severely limited in shale formations, where hydration and swelling of clay minerals lead to wellbore instability. In this study, two novel imidazoline-type inhibitors were synthesized from fatty acids: A-Lin (derived from linoleic acid) and A-Lau (derived from lauric acid). The synthesis involved amidation followed by cyclization, and the products were characterized using FTIR and TGA. Their performance as shale hydration inhibitors was evaluated in WBM formulations and compared with commercial additives (Amine NF and Glycol). The FTIR spectra confirmed successful imidazoline ring formation, while TGA demonstrated good thermal stability up to 150 °C, with A-Lin exhibiting superior resistance due to its unsaturated structure. Rheological tests showed that the synthesized additives reduced plastic viscosity, thereby improving cuttings transport efficiency. Swelling tests revealed that A-Lin achieved the lowest final swelling (6.3%), outperforming both commercial inhibitors and the saturated A-Lau analogue. Furthermore, A-Lin provided the best lubricity coefficient (0.148), reducing torque and drag during drilling. Overall, A-Lin demonstrated strong potential as an efficient, thermally stable, and environmentally compatible shale inhibitor for advanced WBM formulations. Compared to conventional inhibitors such as KCl, glycol, and amine-based additives, A-Lin uniquely combines superior swelling inhibition, enhanced lubricity, and good thermal stability, highlighting its novelty as an imidazoline derivative derived from renewable fatty acids Full article

In this study, we discovered a new diameter-dependent carbon nanotube (CNT) hydrogel composed exclusively of CNTs and tannic acid (TA). Accordingly, we first examined the relationship between the concentrations of CNTs and TA, as well as the CNT diameter, and whether gelation occurred. As a result, we found that when the TA concentration was fixed at 0.15 wt%, the threshold CNT concentration required for gelation was 0.05 wt%, which was lower than the values reported for previously known CNT hydrogels. We also determined that a TA to CNT weight ratio of 2–3 is critical for gelation. Furthermore, we found that subjecting the CNT dispersion to hydrothermal treatment at 160 °C, followed by freezing and ambient drying, produced a CNT aerogel that retained its 3D structure. Then, we evaluated the thermoelectric properties (electrical conductivity and Seebeck coefficient) of the resulting CNT hydrogel and aerogel under a temperature gradient for application. Both materials exhibited stable and reproducible electromotive force, and the measured Seebeck coefficients were comparable to those of conventional CNT-based thermoelectric materials. These findings demonstrate that 3D thermoelectric materials can be readily fabricated from CNT dispersions via simple processes and highlight the potential of these materials for future applications in energy-harvesting devices. Full article

Total alkalinity (TAC) plays a pivotal role in buffering acid–base fluctuations and maintaining pH stability in aquatic ecosystems. This study presents a data-driven approach to model TAC using decision tree regression, applied to a comprehensive dataset of 454 water samples collected in diverse aquatic environments of the Médéa region, Algeria. Twenty physicochemical parameters, including concentrations of bicarbonates, hardness, major ions, and trace elements, were analyzed as input features. The decision tree algorithm was optimized using the Dragonfly metaheuristic algorithm coupled with 5-fold cross-validation. The optimized model (DT_DA) demonstrated exceptional predictive performance, with a correlation coefficient R of 0.9999, and low prediction errors (RMSE = 0.3957, MAE = 0.3572, and MAPE = 0.4531). External validation on an independent dataset of 68 samples confirmed the model’s robustness (R = 0.9999; RMSE = 0.4223; MAE = 0.3871, and MAPE = 0.4931). The tree structure revealed that total hardness (threshold: 78.5 °F) and bicarbonate concentration (threshold: 421.68 mg/L) were the most influential variables in TAC determination. The model offers not only accurate predictions but also interpretable decision rules, allowing the identification of critical physicochemical thresholds that govern alkalinity. These findings provide a valuable tool for anticipating pH instability and guiding water quality management and protection strategies in freshwater ecosystems. Full article