Search Results (92,434)

This study presents a sustainable strategy for improving the thermal properties of pine wood through the application of calcium carbonate nanopowder (CCNP) chelated with polycarboxylic acids (citric acid (CA) and tartaric acid (TA)) as coatings. The chelation reaction was confirmed by the detection of carbon dioxide (CO₂) gas. CCNP was characterized using microscopy and particle size analysis. The formation of crystalline calcium citrate and calcium tartrate was verified using FTIR and Raman spectroscopies, and XRD analysis. Wood treatment was conducted using different volumetric ratios of CA and TA. The CA-TA-treated (coated) wood blocks achieved the highest mass gain after treatment of around 89%, while the pure TA treatment exhibited enhanced leaching resistance, maintaining around 69% mass gain after leaching test. TGA conducted under oxidative (air) conditions showed that the coatings promoted char formation and produced inorganic residues from 6.4% to 7.8%, with the control resulting in negligible residual mass. Flame retardancy tests showed that the chelated coatings effectively delayed combustion and inhibited heat transfer, with the TA treatment showing improved flame retardancy performance by limiting the surface temperature to ~200 °C after 60 s of exposure, as compared to >550 °C for the control. Full article

The Acronicta major larva is a toxic agricultural pest that poses severe ecological management challenges. This study presents a sustainable strategy to valorize this hazardous biological waste into functional nanotherapeutics for insomnia by leveraging its unique intrinsic chemical composition. Carbon dots derived from Acronicta major larva (AM-CDs) were synthesized via one-step pyrolysis, which facilitated the natural molecular pre-assembly of N,S-codoping. Their physicochemical properties and cytotoxicity were evaluated using a series of characterizations and the CCK-8 assay. The sedative and hypnotic effects were assessed in mice with PCPA-induced insomnia through hot plate, Open Field and pentobarbital-induced sleep tests, and their potential mechanism was explored via neurotransmitter detection. The thermal process effectively eliminated intrinsic toxicity while retaining bioactivity via in situ heteroatom doping. AM-CDs exhibited favorable biocompatibility and significant sedative–hypnotic activity, reducing anxiety-related agitation without motor impairment. Mechanistically, AM-CDs effectively restored the GABA/5-HT/glutamate axis. Unlike direct central receptor binding, our findings suggest that this therapeutic effect is likely mediated through a systemic or peripheral regulatory pathway. This study demonstrates the conversion of toxic pests into safe and intrinsically bioactive nanomaterials, providing a dual solution for ecological pest management and novel neuroactive agent development, and validating the “Waste-to-Wealth” concept in biomedicine. Full article

The Ecological Conservation Redline (ECR) is a key spatial policy tool in China’s efforts to protect the Ecosystem Services (ES) of Hainan Island. However, its effectiveness in promoting the coordinated restoration of Hainan Island’s ES remains unclear. This study employs the InVEST model to assess the spatiotemporal dynamics of carbon storage, habitat quality, water yield, and soil retention within the ECR zones of Hainan Island from 1990 to 2020. A Multiple Ecosystem Service Landscape Index (MESLI) was constructed, and Geographically Weighted Regression (GWR) was applied to examine the influence of ECR implementation on ES synergies and the spatial drivers underlying these patterns, aiming to elucidate the complex interactions between conservation policy and ecosystem functioning. The results show that (1) the delineation of the ECR has facilitated ecological restoration in the region. MESLI detrimentally declined before 2010 but positively increased by 12.7% during 2010–2020, indicating an improvement consistent with the period of ECR implementation. Moreover, (2) ESs within the ECR display marked spatial heterogeneity. GWR results reveal that MESLI is positively associated with vegetation cover and slope, and negatively associated with population density, with pronounced disparities in northern and central regions that call for differentiated governance strategies. Finally, (3) constructing a composite evaluation framework based on multiple ESs contributes to optimizing the delineation and management of ECRs, enhancing their scientific support for regional sustainable development. This study provides decision-making guidance for the zoned governance of conservation areas on tropical islands and offers insights for redline management in other ecologically sensitive regions. Full article

Accurate prediction of spring phenology is critical for understanding ecosystem carbon and water dynamics under changing climates. In this study, we applied a revised optimality-based model (R-OPT) that integrates a mechanistic photosynthesis framework into the existing OPT model to simulate leaf unfolding date. We evaluated R-OPT alongside three widely used models—Growing Degree Days (GDD), Chilling–Forcing Trade-off (CFT), and Optimality-based (OPT) models—across multiple Plant Functional Types (PFTs) and sites using repeated 5-fold cross-validation. Findings reveal that R-OPT consistently outperforms the other models, achieving the lowest median RMSE (13.11 days), indicating enhanced predictive accuracy and explanatory power. Although the model incurs slightly higher complexity (median AIC = 13.44), the improvement in prediction justifies the trade-off. Our results highlight the importance of incorporating plant functional traits and environmental heterogeneity in phenological modeling. PFT-specific differences, such as the lower RMSEs for evergreen forbs and deciduous broadleaf PFTs versus larger uncertainties for drought-deciduous and semi-evergreen PFTs, underscore that current models may insufficiently capture key environmental drivers, including precipitation and partial leaf retention. Latitudinal and elevational variations in trade-off parameter a, and the prominence of leaf-level carbon assimilation traits (Aleaf) as drivers of phenology, demonstrate the critical role of physiological traits in shaping PFT-specific phenological timing. These findings have significant implications for large-scale ecosystem modeling. By linking phenology directly to photosynthetic processes, R-OPT enhances predictive skill and biological interpretability, supporting improved simulations of carbon and water fluxes. Overall, R-OPT offers a mechanistically grounded and robust framework for advancing predictive understanding of spring phenology and its ecological and climate-relevant consequences. Full article

Urban curbside loading and unloading zones are increasingly affected by competing non-logistics uses, such as outdoor terraces or resident parking, leading to reductions in effective curbside length. These design decisions can significantly alter service capacity and generate environmental externalities in urban freight operations that are rarely quantified. This study introduces the Factor of Occupancy (F_o) as a space–time design indicator for curbside unloading zones, defined as the product of effective curbside length and the maximum authorised dwell time. Using direct observational data from an urban block in Zaragoza (Spain), the analysis focuses on a loading and unloading zone whose effective length was reduced by approximately 6 m due to the installation of a restaurant terrace. Two curbside configurations are compared: a reduced configuration (8 m) and a restored configuration (14 m), keeping demand and temporal constraints constant. F_o is integrated into a loss-based queueing model (M/M/1/1) to estimate blocking probabilities and the number of served and rejected freight operations. To capture the environmental implications of curbside capacity loss, the paper proposes the Hidden Carbon Emissions (HCE) indicator, which quantifies the additional CO₂ emissions generated by rejected vehicles through block recirculation and idling during illegal occupancy, based on observed behaviour and publicly available emission factors. The results show that restoring curbside length substantially increases effective service capacity and reduces rejected vehicles, leading to a marked decrease in hidden CO₂ emissions per operation. The findings highlight that minor curbside design decisions can produce measurable impacts on both urban freight efficiency and environmental performance. Full article

Metabolic reprogramming is a defining feature of breast cancer, enabling tumor cells to sustain rapid proliferation, survive under stress, and resist therapy. Key pathways including glycolysis, glutaminolysis, lipid metabolism, and one-carbon metabolism, play central roles in meeting the energetic and biosynthetic demands of malignant cells. Enhanced glycolytic flux supports ATP generation and lactate production, while glutamine metabolism fuels the tricarboxylic acid cycle and provides nitrogen for nucleotide synthesis. Lipid metabolic pathways, particularly fatty acid synthesis, contribute to membrane biogenesis and signaling, and one-carbon metabolism driven by serine and glycine supplies methyl groups for epigenetic regulation and nucleotide production. These metabolic adaptations not only promote tumor growth but also create vulnerabilities that can be exploited therapeutically. Inhibiting these pathways has shown promise in preclinical models; however, challenges such as metabolic plasticity, tumor heterogeneity, and potential toxicity in normal tissues underscore the need for biomarker-driven strategies and rational combination therapies. Herein, we describe current knowledge of the role of these pathways in breast cancer progression, highlighting the role of key enzymes in promoting breast cancer tumor cell growth and in breast cancer prognoses. Full article

Against the backdrop of promoting green buildings and a circular economy, the development of efficient, sustainable, and low-carbon cementitious materials is of great significance for reducing resource consumption and carbon emissions. In this study, plant ash (PA) was used as a partial cement replacement, and a series of alkali-activated composite cementitious materials (APAG) were prepared by regulating the dosages of PA and alkali activator (AA). The evolution of their workability, hydration behavior, and mechanical properties was systematically investigated. The results show that the incorporation of PA effectively delayed the setting process of the system; compared with P0, the initial and final setting times of P20 increased by approximately 302% and 100%, respectively, thereby mitigating the excessively rapid early-age reaction of the alkali-activated system while causing only a slight reduction in flowability. In contrast, the addition of AA shortened the setting time of APAG and led to a gradual decrease in fluidity. When the PA dosage was 20% and the AA dosage was 4%, APAG achieved a 28 d compressive strength of 57.8 MPa while maintaining good workability. Further analysis revealed a strong linear correlation between compressive strength and chemically bound water content under different PA and AA dosages, indicating that the reaction degree is a key factor governing macroscopic mechanical performance. Microstructural characterization confirmed that the incorporation of PA and AA significantly altered the reaction pathways and the morphology of hydration products, providing a reasonable microstructural explanation for the evolution of macroscopic properties. These findings provide valuable insights into the high-value utilization of biomass waste and the broader application of green cementitious materials. Full article

Degraded non-cracking soils (locally known as Naga’a) are widespread in semi-arid regions of Sudan and are characterized by severe compaction, low organic matter, poor water retention, and limited crop productivity. Sustainable rehabilitation strategies for these soils remain underexplored. This study evaluated the potential of farmyard manure compost (FYM) as a soil amendment to improve physicochemical properties, soil water retention, and sorghum (Sorghum bicolor L.) performance in degraded Naga’a soil. Aerobic composting of FYM was conducted for two months under controlled moisture and C/N ratio conditions, producing a mature compost with enhanced organic carbon, nitrogen, and water-holding capacity. A pot experiment was conducted using five rates (0, 5, 10, 15, and 20 t ha⁻¹) of the produced compost alongside a mineral NPK treatment, assigned in a randomized complete block design. Compost application significantly (p ≤ 0.05) increased soil organic carbon, total nitrogen, total phosphorus, saturation percentage, and water-holding capacity compared with the control and NPK treatments. The highest compost rate (20 t ha⁻¹) improved soil water-holding capacity by approximately 20% and organic carbon by over 90% relative to the control. Sorghum dry matter production and plant nutrient uptake (N, P, K, and Ca) increased significantly with compost rate, while total seasonal irrigation water requirements declined. Water productivity improved progressively with compost addition, reaching a maximum increase of 60.5% at 20 t ha⁻¹ compared to the control. Overall, FYM proved effective in restoring soil functional properties, enhancing water-use efficiency, and improving sorghum growth. The results highlight the valorization of FYM as a sustainable, low-cost strategy for rehabilitating degraded non-cracking soils in arid and semi-arid environments. Full article

Partial oxidation of methane (POM) is a good way to make syngas because it uses exothermic reactions to keep itself going. This study made a series of Ni/KIT-6 catalyst precursors with Gd (0.5–2 wt.%) added to them and then carefully looked at how they changed into active catalysts. The first tests on the precursors using N₂ physisorption, XRD, and H₂-TPR showed that they had a high surface area and changed how they reduced. However, the high-temperature activation (700 °C) and reaction (682 °C) conditions caused thermal evolution and sintering. Tests of catalytic performance and RSM optimization found that the 5Ni + 1Gd/KIT-6 formulation was the best. Under the best conditions, it converted 89.0% of CH₄ and 87.4% of H₂. Using TEM and Raman spectroscopy to look at the used catalysts showed that 1 wt.% Gd was able to control the size distribution of the metallic particles and stop disordered carbon from forming, even after thermal recrystallisation. A 24 h stability test confirmed these findings, indicating a stable H₂ yield (85–87%) and minimal performance degradation, thereby demonstrating that Gd promotion maintains the stability of the active metallic phase under operational stress. Full article

To promote the resource utilization of oilfield solid waste and facilitate the green and low-carbon transformation of transportation infrastructure, this study employed drilling cuttings from the Maye area of the Xinjiang oilfield and coal-fired furnace ash as primary raw materials. NaOH, Na₂O·nSiO₂, and Ca(OH)₂ were used as alkali activators to prepare alkali-activated solidification materials for oilfield road base applications. The optimal curing system identified in this study (4 wt.% NaOH + 20 wt.% furnace ash) falls within the commonly reported dosage ranges for alkali-activated solid-waste materials, where NaOH contents are typically 3%–8% and furnace ash contents 15%–30%. Considering the distinct chemical characteristics of the Xinjiang oilfield solid wastes, a targeted optimization strategy was adopted to achieve a balance between mechanical performance and economic feasibility. Based on mix-proportion experiments, macroscopic mechanical properties were evaluated. In combination with X-ray diffraction (XRD), laser particle size analysis, simultaneous thermal analysis (TG–DSC), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), the influence of activator type on both mechanical performance and microstructural evolution was systematically investigated. The results indicate that the system containing 4 wt.% NaOH + 20 wt.% furnace ash exhibits the best overall performance, achieving a 28-day compressive strength of 4.81 MPa and a splitting tensile strength of 0.41 MPa, which are significantly higher than those of the Na₂O·nSiO₂ system (3 wt.% Na₂O·nSiO₂ + 20 wt.% furnace ash) and the Ca(OH)₂ system (4 wt.% Ca(OH)₂ + 15 wt.% furnace ash). The primary hydration products were identified as C-(N)-A-S-H and C-S-H gels. The type of alkali activator plays a decisive role in regulating hydration reaction kinetics and the spatial distribution of Ca and Si elements, thereby governing the hierarchical differences in macroscopic mechanical properties. In particular, NaOH generates a highly alkaline environment that promotes the dissolution of active Si/Al components in both drilling cuttings and furnace ash, enhances gel polymerization, and results in a denser microstructure. This study provides theoretical and technical support for the high-value utilization of oilfield solid wastes in highway base engineering. Full article

Lake Van (Eastern Turkey), the world’s largest soda lake, represents a unique geochemical environment characterized by high alkalinity (pH about 9.7) and a complex hydrochemistry, driven by deep hydrothermal input and extreme evaporative processes. This article evaluates mineralogy, minor elements, and Rare Earth Element (REE) geochemistry of coastal stromatolites from 11 sites, to discriminate between endogenous chemical signals and terrigenous contamination. Results identify two distinct lithological groups: a chemically pure authigenic end-member (CaCO₃ > 85%), overprinted by a significant siliciclastic detrital contribution, rich in SiO₂, Al₂O₃, and Fe₂O₃. Authigenic samples successfully preserve the primary hydrothermal signature, exhibiting marked Heavy Rare Earth Element (HREE) enrichment and superchondritic Y/Ho ratios (=35), inherited from the stability of dissolved dicarbonate complexes, such as [REE(CO₃)₂]⁻, which favor HREE solubility and uptake into the carbonate lattice. Conversely, the significant detrital contribution is highlighted by a robust correlation between REE and lithogenic proxies (Al-Si-Fe). Furthermore, the non-CHARAC behavior observed in Y/Ho and Zr/Hf twin pairs effectively distinguishes biogenic-chemical precipitation from detrital inputs. These results highlight the effectiveness of REE geochemistry as a proxy to filter out lithogenic overprints and accurately isolate the primary hydrochemical record of carbonate stromatolites. Full article

Despite the significant environmental impact of the healthcare sector, with Germany’s system accounting for a large proportion of national emissions, quantitative sustainability research on specific medical procedures, such as those in dentistry, is critically scarce. This study aimed to address this issue by conducting a Life Cycle Assessment to quantify and compare the Global Warming Potential of the conventional analog and the digital (intraoral scanner) impression techniques for the manufacturing of single-tooth crowns in a German dental practice. The methodology employed a cradle-to-grave approach, defining a positive dental model as the functional unit and focusing on material consumption, waste streams, and equipment usage while excluding patient travel and facility energy. The results revealed that the digital impression procedure offers significant environmental advantages, with its average carbon footprint (approx. 550 CO₂-eq) being nearly threefold lower than the analog impression (approx. 1620 g CO₂-eq). This difference is primarily driven by the analog impression technique’s intensive use of disposable materials and the generation of contaminated waste requiring incineration. In contrast, the digital impression’s burden shifts to the manufacturing of the intraoral scanner, highlighting the importance of high clinical utilization to achieve the ecological benefit. This work concludes that the adoption of digital impression taking is a critical step towards more sustainable dentistry by promoting material avoidance and waste reduction, provided that high equipment utilization rates can be ensured. It should be noted that these results are specific to the regional context, particularly the German energy mix and national waste management standards, and may vary in different geographical settings Full article

Accurate prediction of wear behavior in polymer nanocomposites remains challenging due to the coupled influence of operating conditions and evolving surface morphology. In this study, a surface-aware triboinformatics framework is proposed to predict the dry sliding wear behavior of multi-walled carbon nanotube (MWCNT) reinforced epoxy composites by integrating operating parameters with run-wise atomic force microscopy (AFM) surface descriptors. Wear experiments were conducted using a Taguchi L16 design by varying CNT content (0–0.75 wt.%), applied load (10–40 N), sliding speed (183–458 rpm), and sliding distance (500–1250 m). AFM-derived parameters, including Ra, Rq, Z-range, and surface area difference, were extracted from the worn surface corresponding to each experimental run. Multiple regression-based machine learning models were evaluated using leave-one-out cross-validation, with ensemble-based models providing the best predictive performance (R² > 0.85 with low RMSE and MAE). Feature importance and partial dependence analyses identified CNT content as the dominant factor controlling wear reduction, followed by Z-range and Ra, highlighting the critical role of surface damage severity. Neat epoxy exhibited a maximum wear loss of 0.444 mg, whereas the 0.75 wt.% CNT composite showed values as low as 0.003 mg under comparable conditions, corresponding to a reduction of approximately 99%. The proposed framework enables mechanistically interpretable wear prediction and supports the design of durable polymer composites, contributing to SDG 9 (Industry, Innovation and Infrastructure) and SDG 12 (Responsible Consumption and Production). Full article

The invasive aquatic plant Myriophyllum aquaticum represents both an ecological threat and a wet biomass disposal challenge. This study investigates hydrothermal carbonization (HTC) as a strategy for its valorisation into energy-dense hydrochar. A Design of Experiments–Response Surface Methodology (DoE-RSM) approach was applied to elucidate the combined influence of temperature (200–260 °C), residence time (30–210 min), and solid load (5–25 wt%) on hydrochar yield and properties. Hydrochar yields ranged from 48.8% to 65.6%, with the highest yields achieved at 200 °C, 30 min, and 25 wt% solids. Higher heating values of hydrochars spanned from 12.14 to 14.53 MJ/kg, corresponding up to +19% energy densification at higher process severity. Carbon and energy yields reached 69.7% and 68.6%, respectively, with maximum values attained under low-severity, high-solid-load conditions. The predictive models exhibited strong agreement with experimental data, enabling optimisation of HTC parameters for targeted hydrochar applications. Two hydrochars, “peat-like” and “lignite-like”, were further characterised for their potential use as soil amendments. The lignite-like hydrochar complied with EU contaminant limits and showed no phytotoxicity, confirming its suitability for agronomic use. Overall, HTC of M. aquaticum provides an effective waste-to-resource pathway, transforming wet invasive biomass into value-added carbon materials. Full article

Mangrove ecosystems are important blue carbon systems and play a critical role in understanding carbon cycling and responses to climate change. However, accurate regional estimation of Net Ecosystem Exchange (NEE) remains challenging due to the environmental complexity and spatial heterogeneity. This study combined eddy covariance observations from four mangrove sites along China’s southeastern coast (natural and restored mangrove forests) with multi-source remote sensing and environmental reanalysis data to construct three variable schemes (site observations only, with added vegetation indices, and comprehensive multi-source variables). We compared three machine learning models for daily NEE prediction, including eXtreme Gradient Boosting (XGBoost), Random Forest (RF), and Support Vector Machine (SVM). The results showed that: (1) Restored and natural mangroves exhibited similar temporal NEE dynamics and consistently functioned as carbon sinks, restored mangrove sites showed greater cross-site variability. Among the study sites, CN-LZR exhibited the strongest cumulative carbon uptake. (2) Scheme 3 combined with the XGBoost algorithm achieved the highest predictive accuracy, reaching an R² of 0.73 across sites. Differences among machine learning models were primarily associated with their ability to capture nonlinear interactions between atmospheric and hydrological variables, with tree-based models outperforming SVM. (3) SHAP analysis indicated that radiation-related variables were the dominant drivers of NEE, while hydrological influences were site-dependent; and (4) Regional upscaling indicated that all sites consistently functioned as long-term carbon sinks, with CN-LZR exhibiting slightly higher daily mean carbon uptake than the other sites. This study presented the first machine learning framework for estimating daily-scale NEE in mangroves, providing methodological and data support for regional carbon flux assessment and blue carbon management. Full article