Search Results (45,935)

This study investigates geothermal waters in the Xinjiang region through hydrogeochemical methods, including cluster analysis, ionic ratios, and isotopic analysis. Cluster analysis categorized the geothermal water samples into three distinct groups (G1, G2, and G3). The predominant hydrochemical facies are SO₄-HCO₃-Na, SO₄-Cl-Na, and Cl-Na types, whose formation is controlled by multiple factors. Evidence from molar ratios of major ions suggests that geothermal waters in Group G1 are predominantly governed by water–rock interactions, whereas Groups G2 and G3 are mainly influenced by evaporative concentration. Hydrogen and oxygen isotopic signatures confirm that meteoric water serves as the primary recharge source for these geothermal waters. The spatial correlation between regional tectonic features and most geothermal discharge points demonstrates a consistent relationship between geothermal water occurrence and structural distribution in Xinjiang. Additionally, a conceptual circulation model is proposed wherein meteoric water undergoes deep circulation following local recharge, ascends along fault zones under tectonic pressure, and mixes with shallow groundwater. This research primarily elucidates the hydrogeochemical characteristics and recharge mechanisms of geothermal resources in Xinjiang, thereby providing a scientific basis for their future development and utilization. Full article

Fine particulate matter (PM_2.5; aerodynamic diameter ≤ 2.5 µm) remains a challenging policy for industrialized coastal regions throughout East Asia. In this study, we present a multi-year chemical characterization of PM_2.5 and identify key factors contributing to extreme pollution events in Dangjin, a heavy-industry hub on Korea’s west coast. Between August 2020 and March 2024, 24-h gravimetric filters (up to n = 245; 127–280 valid analyses depending on constituent) were collected twice weekly in winter–spring and weekly in summer–autumn. Meteorological data and 48-h backward HYSPLIT trajectories guided source interpretation. The mean PM_2.5 concentration was 26.22 ± 15.29 µg/m³ (4.74–95.31 µg/m³). The mass was highest in winter (30.83 µg/m³). Secondary inorganic ions constituted 60.3% of the aerosol, with nitrate comprising 29.7%. A nitrate-to-sulfate ratio of 1.94 indicated a stronger influence from mobile NO_x emissions compared to that from coal combustion. The trajectory analysis showed north-easterly transport from Eastern China, followed by local stagnation, which promoted rapid ammonium-nitrate formation. Regional transport contributes to severe PM_2.5 episodes, with their magnitude increased by local NO_x and NH₃ emissions. Our findings suggest that effective mitigation strategies in coastal industrial corridors require coordinated control of long-range transport and domestic measures focused on vehicles and ammonia-rich industries. Full article

The rapid growth of electric vehicle (EV) adoption in Malaysia is projected to generate substantial volumes of end-of-life lithium-ion batteries, creating both environmental challenges and opportunities for repurposing into second-life batteries (SLBs). This study investigates the technical, economic, and regulatory feasibility of deploying SLBs for photovoltaic (PV) energy storage in petrol stations, an application aligned with the nation’s energy transition goals. Laboratory testing of Nissan Leaf ZE0 battery modules over a 120-day operation period demonstrated stable cycling performance with approximately 7% capacity fade, maintaining state-of-health (SOH) above 47%. A case study of a 12 kWp PV–SLB hybrid system for a typical Malaysian petrol station shows 45 kWh of usable storage, capable of offsetting a daily electricity demand of 45 kWh, reducing capital cost by 30–50% compared to new lithium-ion systems, and achieving 70–80% lifecycle CO₂ emission reductions. The proposed architecture leverages SLBs’ suitability for slower, steady discharge to provide reliable nighttime operation and grid load relief, particularly in semi-urban and rural stations. Beyond technical validation, the paper evaluates economic benefits, environmental impacts, and Malaysia’s regulatory readiness, identifying gaps in certification standards, reverse logistics, and workforce skills. Strategic recommendations are proposed to enable large-scale SLB deployment and integration into hybrid PV–petrol station systems. Findings indicate that SLBs can serve as a cost-effective, sustainable energy storage solution, supporting Malaysia’s National Energy Transition Roadmap (NETR), advancing circular economy practices, and positioning the country as a potential ASEAN leader in battery repurposing. Full article

Due to the presence of stray current in the subway environment, the durability issues of subway structures differ from those of general structures. This study simulates the combined effects of chloride ions and stray current in the subway environment through electrochemical corrosion experiments, thereby analyzing the corrosion morphology and mechanical property degradation of steel strands and the corrosion-induced cracking of concrete. The experimental results indicate that stray current affects the strength and ductility of steel strands as well as the cracking of concrete. The corrosion difference coefficient μ_c at different positions is greater than 1.6 and the average corrosion degree η_ave is less than 7%. The corrosion morphology gradually changes from non-uniform to uniform corrosion until the η_ave is greater than 12%. The concrete crack width under a stray current of 60 mA is 10.67 times that of cracks under 20 mA after 42 days, which is approximately linearly related to the current intensity. Based on the experimental results, a corrosion-induced crack prediction model for prestressed concrete under stray current is proposed, with the main influencing factors being current intensity, concrete tensile strength, and protective layer thickness. These findings can provide valuable references for the durability analysis of subway structures. Full article

Metal components that undergo ultrasonic cleaning are often stored in rinse water before drying; during this dwell period, surface corrosion can nucleate and grow. Here, we investigate how two easily monitored water-quality parameters—chloride ion concentration (Cl⁻) and chemical oxygen demand (COD), a proxy for residual organic species—govern the initiation and propagation of corrosion on low-carbon steel. After ultrasonic cleaning in five representative cleaning solutions, test coupons were immersed for up to 72 h in the corresponding rinse water and the extent of corrosion was quantified by optical profilometry and mass loss. The surface area covered by corrosion scaled linearly with [Cl⁻] (0–150 mg L⁻¹) and COD (5–120 mg L⁻¹), with correlation coefficients of 0.92 and 0.88, respectively. When both parameters exceeded threshold values of 50 mg L⁻¹ (Cl⁻) and 30 mg L⁻¹ (COD), the corrosion rate doubled relative to the control. A two-step mitigation strategy—ion-exchange pretreatment followed by activated-carbon polishing—reduced Cl⁻ and COD below the thresholds and suppressed corrosion formation by >70%. These findings provide a simple water-quality guideline and a low-cost process retrofit for manufacturers that store steel parts in high-humidity environments. Full article

Background/Objectives: Sentinel lymph node biopsy (SLNB) is currently the standard approach for axillary staging in breast cancer. Conventional techniques are radioisotope-based (Technetium-99m, Tc99m) and remain widely used, but novel tracers like Indocyanine Green (ICG) fluorescence provide potential advantages regarding feasibility and logistics. Methods: We conducted a prospective, observational study including 476 female patients diagnosed with primary invasive breast cancer who underwent SLNB at the Institute of Oncology “Prof. Dr. I. Chiricuță”, Cluj-Napoca, Romania, between January 2022 and May 2025. Clinical, surgical, and pathological variables were systematically extracted. SLNB was performed using either Tc99m or ICG, according to institutional protocols. Comparative analyses were performed to evaluate sentinel node characteristics, histopathological parameters, and positive surgical margins predictors. Results: The median age was 60 years (IQR: 52–69). Breast-conserving surgery (BCS) was performed in 77.9% of cases, while mastectomy was performed in 22.1%. Sentinel lymph node positivity was reported in 25.6% of cases, with no significant differences in the number of excised or metastatic nodes between Tc99m and ICG (mean nodes: 3.23 vs. 3.20, p = 0.860; mean positive nodes: 0.35 vs. 0.36, p = 0.897). Histologically, invasive carcinoma NST was predominant (90.1%), and surgical margins were negative in 96.8% of patients, with all margin-positive cases occurring following BCS. No pathological markers (grade, Ki67, TILs, DCIS extent) predicted margin status or nodal involvement. Notably, younger age correlated inversely with the extent of ductal carcinoma in situ (r = −0.21, p < 0.00001). Conclusions: Tc99m and ICG provided comparable diagnostic performance in performing SLNB, with equivalent rates of nodal detection and pathological yield. These findings support that ICG is a safe and effective alternative for routine axillary staging in breast cancer. Full article

Background: In this study, hydroponic experiments were conducted to examine the roles of sulphur (S), calcium (Ca), and nitric oxide (NO) in alleviating salt stress (20 mM NaCl) in tomato (Solanum lycopersicum L.) seedlings. Methods: Analyses included Na⁺/K⁺ contents, inorganic nitrogen (nitrate, nitrite, ammonium), nitrogen- and ammonium-assimilating enzymes (NR, NiR, GS, GOGAT), sulphur-assimilating enzymes (ATPS, OASTL), protein content, ROS (O₂^∙−, H₂O₂), and in vivo NO visualization were conducted. Results: We observed that salt stress increased Na⁺, reduced K⁺, disrupted nitrogen and sulphur metabolism, elevated ROS, and decreased NO, causing oxidative stress and reduced enzymatic activity. Supplementation with potassium sulphate (40 µM), calcium chloride (30 µM), and sodium nitroprusside (SNP; 40 µM) mitigated these effects, enhancing enzymatic activities, restoring Na⁺/K⁺ balance, improving protein content, and lowering ROS. The protective role of NO was confirmed using inhibitors L-NAME (500 µM) and cPTIO (100 µM), which reversed SNP’s benefits and aggravated stress damage. Conclusion: Overall, S, Ca, and NO were found to synergistically improve salt stress tolerance by modulating ion homeostasis, nitrogen and sulphur metabolism, and oxidative balance, offering nutrient- and signal-based strategies to enhance tomato resilience under salinity. Full article

The development of effective materials for uranium extraction from seawater is vital for advancing sustainable energy solutions. However, the efficient recovery of uranium from seawater presents significant challenges due to its extremely low concentration, the presence of competing ions, and the complex marine environment. To address these issues, various materials such as inorganic and organic sorbents, chelating resins, nanostructured sorbents, and composite materials have been explored. More recently, the functionalization of carbon-based materials for enhanced adsorption properties has attracted much interest because of their high specific surface area, excellent chemical and thermal stability, and tunable porosity. These materials include activated carbon, graphene oxide, biochar, carbon cloths, carbon nanotubes, and carbon aerogels. The enhancement of carbonaceous materials is typically achieved through surface functionalization with chelating groups and the synthesis of composite materials that integrate other high-performance sorbents. This review aims to summarize the work of these functionalized carbon materials, focusing on their adsorption capacity, selectivity, and durability for uranium adsorption. This is followed by a discussion on the binding mechanisms of uranium with major chelating functional groups grafted on carbonaceous sorbents. Finally, an outlook for future research is suggested. We hope that this review will be helpful to researchers engaged in related studies. Full article

Antioxidants regulate oxidative reactions by impeding, delaying, or inhibiting the oxidation of biomolecules. Concerns regarding the toxicity of synthetic antioxidants have driven the search for safer alternatives. In this study, the antioxidant activities of three nontoxic carbon-based nanomaterials—carbon dots from citric acid precursor (CB-Ca), iron-doped carbon dots (CB-Fe) and carbon dots derived from Momordica charantia leaves (CB-Mc)—were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydrogen peroxide (H₂O₂) scavenging, ferric-reducing antioxidant power, and total antioxidant capacity (TAC) assays. Scavenging activity was carried out at varying concentrations, and half-maximal inhibitory concentration (IC₅₀) was calculated using non-linear regression. Reductive ability and TAC were expressed as mg ascorbic acid equivalents/g nanomaterial. CB-Fe exhibited the most potent DPPH scavenging activity (IC₅₀ = 254.2 ± 37.37 µg/mL), surpassing CB-Mc and CB-Ca by 2- to 3-fold. In contrast, CB-Ca had the highest H₂O₂ scavenging (IC₅₀ = 84.2 ± 11.87 µg/mL), while CB-Mc had the highest TAC of 77.95 mg ascorbic acid Eq/g. CB-Fe also displayed superior ferric ion reducing capacity. The study concluded that each carbon dot type exhibits unique antioxidant profiles and may offer some special advantages in nanomedicine and other applications. Full article

Microsomal fractions from yeast Δale1 cells harbouring the empty plasmid pYES2/CT and from yeast cells overexpressing PtATS2a (Phatr3_J11916) or PtATS2b (Phatr3_J43099) were used in the studies. When sn-1-18:1-LPA and [¹⁴C]16:0-CoA were used as exogenous substrates, both PtATS2a and PtATS2b showed the highest activity at 23 °C in the range of temperatures tested from 10 to 60 °C. Both enzymes showed the highest activity in alkaline pH. For PtATS2a, it was pH 10 while for PtATS2b, it was pH 11. At pH 6 and pH 12, the activities of both enzymes were very low. The calcium ions at concentrations of 0.05–1 mM drastically decreased the activity of both enzymes. The magnesium ions at a concentration of 0.05 mM had a little effect on the activity of both enzymes, while higher concentrations (0.5 mM and 1 mM) significantly inhibited their activity. To study the substrate specificity, seventeen different acyl-CoAs in combinations with sn-1-[¹⁴C]18:1-LPA were used. PtATS2a showed the highest preference for 18:4-CoA n-3 while PtATS2b for 18:1-CoA. The pattern of utilisation of other acyl-CoAs tested also differed between the two enzymes. The presented studies, for the first time, characterised LPAAT type enzymes from diatoms, organisms that naturally produced very-long-chain polyunsaturated fatty acids (VLC-PUFA). Full article

Phase-change memory (PCM) is a promising candidate for in-memory computation and neuromorphic computing due to its high endurance, low cycle-to-cycle variability, and low read noise. However, among other factors, its performance strongly depends on the post-lithography fabrication steps. This study examines the impact of reactive ion etching (RIE) on PCM device performance by evaluating different etching gas mixtures, CHF₃:O₂, H₂:Ar, and Ar, and determining their impact on key device characteristics, particularly initial resistance and cycling stability. The present study demonstrates that a two-step etching approach in which the capping layer is first removed using H₂:Ar and the underlying GST layer is subsequently etched using physical Ar sputtering ensures stable and reliable PCM operation. In contrast, chemically reactive gases negatively impact the initial resistance, cycling stability, and device lifetime, likely due to alterations in the material composition. For the cycling stability evaluation, an advanced measurement algorithm utilizing the aixMATRIX setup by aixACCT Systems is employed. This algorithm enables automated testing, dynamically adjusting biasing parameters based on cell responses, ensuring a stable ON/OFF ratio and high-throughput characterization. Full article

The structure, chemical composition, thermal stability, and abuse responses of cathode materials are critical to the safety and economy of lithium-ion batteries (LIBs). This review systematically summarizes advances in research on how cathode materials influence LIB thermal runaway (TR) behavior. It analyzes the oxygen release from cathodes in TR mechanisms and the hazards of such oxygen generation during TR, expounds on how differences in cathode structure, chemical composition, and thermal stability affect TR behavior, and summarizes the thermal characteristics of LIBs with different cathodes under mechanical, electrical, and thermal abuse. Results indicate that oxygen released from cathode decomposition during TR oxidizes electrolytes, releasing substantial heat and gas and causing more severe TR hazards. Structural instability of cathodes leads to accelerated release of lattice oxygen, speeding up TR initiation. Chemical composition regulates thermal stability, phase transition pathways, and gas generation rates during TR, while elemental ratios affect the ease of TR triggering. Cathodes with poor thermal stability have lower thermal decomposition onset temperatures, making TR more likely to occur and intensifying reaction severity. All three abuse types trigger inherent risks of cathodes, inducing TR and significantly increasing its occurrence probability. Differences in intrinsic properties further extend to the system level, also influencing thermal runaway propagation and fire dynamics at the module level. Future research focusing on the intrinsic properties of cathodes and external abuse is of great significance for addressing LIB TR behavior. Full article

To ensure the highest safety standards in modern automobiles, the industry is constantly adopting zero-defect frameworks, such as AEC-Q100, which aims for defective-parts-per-billion (DPPB) or grade-0 level reliability standards in automotive integrated-circuit (IC) packages. Most contemporary wire-bonded packages use either pure copper (Cu) or palladium (Pd)-coated copper (PCC) wires bonded to aluminum (Al) bond pads as interconnections. This choice is made due to their lower cost and superior electrical and mechanical performance, compared to traditional gold wire-based devices. However, these Cu–Al wire-bonded interconnections are prone to ion-induced lift-off/open-circuit corrosion failures when exposed to even trace amounts (<20 ppm) of extrinsic and/or intrinsic halide (Cl⁻ and Br⁻) contaminants, decreasing device longevity. This study investigates corrosion failure mechanisms in Cu and PCC wire-based devices by subjecting non-encapsulated devices to a highly accelerated aqueous-immersion screening test containing 100 ppm chloride (Cl⁻), 100 ppm bromide (Br⁻), and a mixed-ion solution (MX: Cl⁻ + Br⁻). The screening results indicate that even control PCC-Al devices with a Pd overlayer can be susceptible to Cl⁻ and Br⁻ induced corrosion, with 21 ± 1.6% lift-off failures in MX-solution. In contrast, applying a novel Cu-selective passivation reduced lift-off to 3.3 ± 0.6% and introducing phosphonic-acid-based inhibitor into the MX solution eliminated lift-off failures, demonstrating markedly improved reliability. Full article

Background/Objectives: Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality worldwide. This study evaluates the predictive value of Carcinoembryonic Antigen (CEA) in identifying CRC recurrence following surgical resection. Methods: This retrospective study was realized in the Oncology Institute in Cluj-Napoca and included 88 patients diagnosed with CRC. Clinical, demographic, and tumor-specific data were collected, including TNM staging, tumor histology. CEA levels were recorded before surgery. Receiver Operating Characteristic (ROC) analysis was performed to determine the diagnostic accuracy of CEA in predicting tumor relapse, and the sensitivity and specificity of various CEA cut-off values were assessed. Results: Most patients presented with advanced-stage tumors (T3/T4, 80.6%). CEA levels were significantly higher in patients with lymphatic and perineural invasion and in those with metastases (mean CEA: 45.0 ng/mL for M1 vs. 13.2 ng/mL for M0, p = 0.032). ROC analysis revealed an area under the curve (AUC) of 0.877 (95% CI: 0.763–0.949). A CEA cut-off value of 11.73 ng/mL yielded 100% sensitivity and 74.5% specificity for detecting recurrence; Conclusions: CEA is a valuable non-invasive biomarker for predicting CRC relapse, with high sensitivity and acceptable specificity. Regular CEA monitoring post-surgery can facilitate early detection of recurrence, improving prognosis. 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