Search Results (36,777)

Ammonia (NH₃) is a compelling carbon-free hydrogen carrier. Its catalytic decomposition to produce a hydrogen/nitrogen (H₂/N₂) gas stream is central to the “NH₃-H₂” clean energy cycle, provided that residual NH₃ is removed to fuel-cell-grade purity downstream. This review integrates advances from the past five years across four major catalytic NH₃ decomposition pathways, encompassing conventional thermocatalysis, plasma-catalytic, photo(thermal), and electrically driven catalysis, within a unified mechanistic and practical framework, distinguishing it from existing single-pathway reviews. Noble metal catalysts, particularly Ru-based systems, achieve superior low-temperature activity through support engineering, promoter effects, and active-site construction. However, our analysis reveals that non-noble metal (Fe, Co, Ni) catalysts and their alloys, nitrides, and carbides have made substantial progress, with certain Co-based and bimetallic systems approaching Ru-level performance via interfacial oxygen vacancy engineering and electronic structure modulation. Emerging non-thermal routes effectively overcome thermodynamic barriers, enabling operation at temperatures 200–300 °C below conventional thermal requirements, though each faces distinct challenges in energy efficiency, stability, and scalability. Key challenges remaining across all pathways to practical implementation, including residual NH₃ removal and H₂ purification, catalyst deactivation and stability, heat management and energy efficiency, start-up/shut-down dynamics, as well as system integration and economics, are critically assessed. This review provides theoretical guidance and practical recommendations for developing scalable, low-temperature NH₃ decomposition technologies. Full article

Nitrate is one of the most prevalent inorganic pollutants in groundwater systems. Its concentration directly affects the safety assessment of groundwater quality. To scientifically identify nitrate sources in strontium-rich mineral water and facilitate the protection of mineral water resources, this study selects Chengde City, Hebei Province, as the study area. Nitrate source apportionment was quantified using the MixSIAR model, with uncertainties assessed via cumulative probability distributions. The results show that the nitrate concentration in strontium-rich mineral water of the study area ranges from <0.003 to 70.2 mg/L, with a coefficient of variation of 1.24, indicating high data dispersion. The nitrate sources present a mixed pollution characteristic dominated by natural processes and supplemented by human activities. Nitrification dominates biogeochemical processes of strontium-rich mineral water. Soil nitrogen is the primary contributor to nitrate in mineral water, with an average contribution rate of 70.4%, followed by manure; synthetic fertilizers and rainwater together account for less than 1% of the total. Uncertainty analysis shows that contributions of rainwater, synthetic fertilizer, manure, and soil nitrogen to nitrate in strontium-rich mineral water remain stable (UI₉₅ < 0.15), verifying reliable results. This study provides guidance for protecting mineral water quality and sustainable resource exploitation. Full article

Thienopyrimidine derivatives are emerging as potent scaffolds for cholinesterase inhibition in Alzheimer’s disease therapy. In this work, a novel series of substituted thieno[2,3-d]pyrimidines was synthesized via Gewald’s reaction, followed by cyclization and functionalization through nucleophilic substitution and hydrazone formation. Structural confirmation was achieved using spectroscopic techniques, and biological evaluation was performed against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with donepezil and rivastigmine as reference drugs. Compound 4 emerged as the most potent and selective AChE inhibitor (IC₅₀ = 0.58 µM), while compound 7 also showed strong AChE inhibition (IC₅₀ = 0.63 µM). Notably, compound 9 exhibited superior BChE inhibition (IC₅₀ = 3.05 µM) compared to donepezil (IC₅₀ = 8.41 µM). Dual inhibitory activity was observed for compounds 5, 6, and 11, highlighting their multitarget potential. Molecular dynamics simulations (200 ns) and MM/GBSA binding free energy calculations provided mechanistic insights. Compound 4 showed the most favorable binding energy (ΔGbind = −59.16 kcal/mol), driven by hydrogen bonds with Tyr121 and Glu199 and π-π stacking with Trp83. Residue-level decomposition identified Tyr121, Trp83, Glu199, and Tyr338 as critical contributors to binding stability. Structure–activity relationship analysis confirmed that nitrogen-containing substituents and cyclic amino moieties enhance potency, whereas bulky aromatic groups reduce activity. These findings establish thieno[2,3-d]pyrimidine derivatives as promising candidates for the development of next-generation anti-Alzheimer agents. Full article

Background: Geographic peripherality in Israel is linked to poorer health outcomes and may disproportionately affect patients requiring chronic therapies such as hemodialysis (HD). Though malnutrition and inflammation are strong predictors of morbidity and mortality in HD patients, regional differences in nutritional status and dietary adherence are unclear. Objectives: To examine the association between peripherality and malnutrition risk, dietary intake, and adherence to nutrition guidelines among Jewish Israeli adults on HD. Methods: In this multi-center, cross-sectional study, 154 adult Jewish HD patients were recruited from the northern periphery (n = 66) and central regions of Israel (n = 88). Demographic, clinical, laboratory, and anthropometric data were obtained from medical records. Nutrient intake was assessed using the multi-pass 24 h dietary recall method. Malnutrition risk was classified using BMI and serum albumin; the C-reactive protein-to-albumin ratio (CAR) was also calculated. Adherence to International Society of Renal Nutrition and Metabolism (ISRNM) dietary guidelines was evaluated. Between-group comparisons and multivariable regression analyses were conducted. Results: Overall, participant characteristics were similar between groups; however, coronary heart disease prevalence and dialysis vintage were higher in the periphery. Participants from the periphery had lower serum albumin, blood urea nitrogen, hemoglobin, and blood pressure, but higher LDL cholesterol. Sodium intake was significantly higher and adherence to ISRNM sodium guidelines markedly lower in the periphery. In multivariable analysis, peripherality reduced the odds of meeting sodium recommendations by 92.8%. Adherence to energy and protein guidelines was low in both groups. Nearly half of participants had some level of elevated malnutrition risk using the categorized variable, and an overall difference in the categories of malnutrition risk was detected, driven by the increase in the moderate risk category in the periphery. The composite malnutrition risk variable (any increase in risk vs. no increase in risk) did not differ by peripherality. Peripherality was independently associated with higher percent ideal body weight (%IBW), but not with CAR. Conclusions: Peripherality among Jewish Israeli HD patients is associated with differences in nutrition biomarkers, cardiovascular burden, and dietary adherence, especially sodium intake. Interventions considering peripherality should be explored. Full article

This paper proposes a hybrid, interpretable machine learning framework for the preliminary screening of soil macronutrients using Sentinel-2 and AgroLens data. This study aims not to replace laboratory analysis, but to test the feasibility of obtaining a useful proxy signal for estimating nitrogen (N), phosphorus (P), and potassium (K) content using a limited set of remote sensing and agricultural features. The developed pipeline includes data auditing, leakage control, feature engineering, train-only normalization, group-aware partitioning, baseline/SOTA model comparison, hybrid regression modeling, SHAP interpretation, and uncertainty assessment. The experiment used 4471 AgroLens observations and 126 features derived from Sentinel-2 spectral aggregates, vegetation indices, temporal characteristics, and crop-related parameters. The evaluation indicated that the proposed approach consistently improves forecasting quality relative to baseline models under reduced-input conditions. Linear relationships between target variables ranged from 0.14 to 0.17, while nonlinear relationships reached 0.23. SHAP analysis revealed significant contributions from vegetation indices, crop-specific interactions, and Sentinel-2 spectral channels. The findings support the applicability of the proposed framework for preliminary monitoring, prioritizing field surveys, and decision support in digital agriculture. Although an additional AgroLens control segment was used to assess the robustness of the study, the study did not include independent external validation of the data collected across different geographic or agro-climatic conditions. Full article

The fracture–cave carbonate reservoir in Unit S91 of the Tahe Oilfield is jointly controlled by strike-slip fault activity, karstification, and later-stage fracture development, resulting in reservoir spaces characterized by strong heterogeneity, strong discreteness, and multi-scale superimposition. The inter-well connectivity of this type of reservoir is not governed by the size of a single fracture–cave body or local fracture density, but rather by the spatial configuration among the main controlling fault, the associated fracture network, and the fracture–cave reservoir bodies. As the reservoir enters the middle–high-water-cut development stage, the production differential between dominant connecting channels and weakly connected fracture–cave bodies further enlarges, leading to marked heterogeneity in the remaining oil distribution. Integrating post-stack seismic data, fracture prediction, RGB attribute fusion, production performance, and numerical simulation data, this paper constructs a main fault-controlled fracture–vug coupling probability (MFC-FVCP) model under the constraint of the main controlling fault. Unlike conventional multi-attribute fusion methods that mainly enhance seismic anomaly visualization, the MFC-FVCP model transforms the main fault constraint, fracture connectivity, and fracture–cave reservoir-body effectiveness into a unified coupling probability. The model uses three core components—the main fault response field, the fracture attribute response field, and the fracture–cave reservoir body response field—to characterize the fault-control effect, fracture-network continuity, and effective reservoir-body response, respectively. By evaluating the coupling probability, the inter-well connectivity potential is assessed, the dominant connectivity areas where fractures and fracture–cave bodies synergistically develop under the constraint of the main controlling fault are identified, and potential remaining oil targets are clarified. The predicted connectivity pattern was further constrained by production performance, nitrogen injection response, and staged oil saturation simulation, which improves the reliability of remaining oil enrichment prediction. The results show that the T74 layer is the dominant development interval of fracture–cave reservoir bodies in Unit S91. These fracture–cave bodies are mainly distributed along the main controlling fault and associated fracture zones in beaded, chain-like, and banded patterns, exhibiting distinct fault-and-fracture control characteristics. Potential point A near well TK858XCH features both good reservoir physical properties and insufficient sweep efficiency, making it a key target for subsequent injection–production adjustment and remaining oil tapping. The MFC-FVCP model can incorporate static seismic responses, fracture–cave spatial structures, and dynamic development responses into a unified evaluation framework, providing a quantitative basis for characterizing inter-well connectivity and identifying remaining oil enrichment areas in fracture–cave carbonate reservoirs. Full article

The accumulation of agricultural residues represents a major environmental challenge in developing countries, particularly in tropical regions where inadequate waste management contributes to environmental degradation. Vermicomposting has emerged as a sustainable technology capable of transforming organic waste into nutrient-rich fertilizers through the combined activity of earthworms and microorganisms. This study evaluated the influence of different agricultural residues on the physicochemical properties of vermicompost under tropical conditions in Mozambique. The experiment was conducted at the experimental field of the Catholic University of Mozambique—Faculty of Engineering in Chimoio district, using three substrate types: leguminous residues (T1), cereal residues (T2), and horticulture residues (T3). Each treatment was combined with poultry manure in a 1:1 ratio. Vermicomposting was carried out using Eisenia fetida. Because treatments were not independently replicated, results are presented as descriptive physicochemical characterizations (means ± SD of analytical subsamples). All treatments produced vermicompost with physicochemical characteristics consistent with established maturity criteria: pH 8.03–9.07, moisture 50–76%, and electrical conductivity 527–939 µS/cm, C/N ratio ranged from 15.56 to 20.19, total nitrogen ranged from 1.2 to 1.8%, phosphorus from 0.6 to 0.9%, and potassium from 1.1 to 1.5%. T1 (leguminous residues + poultry manure) showed the highest nutrient concentrations and lowest C/N ratio. These descriptive findings suggest that vermicomposting represents a promising strategy for recycling agricultural residues into vermicompost with characteristics consistent with established maturity criteria, highlighting the importance of substrate selection. The findings suggest that vermicomposting is a promising strategy for sustainable waste management and soil fertility improvement in tropical smallholder systems. Full article

Reducing reliance on chemical nitrogen fertilizers while maintaining rice productivity is a key challenge in sustainable agriculture. In this study, a composite inoculant of three diazotrophic strains (Paenibacillus azotifigens, Paenibacillus azotofixans, and Phytobacter diazotrophicus) was applied by root drenching at the heading stage of field-grown rice. Soil physicochemical properties, rice yield, and soil bacterial and fungal communities were assessed at harvest using spike-in-based absolute quantification amplicon sequencing. Inoculation increased rice yield by 5.5% and significantly elevated soil nitrate nitrogen (NO₃⁻-N) (+343%), with a trend toward higher available phosphorus, while total nitrogen, phosphorus, and carbon remained unchanged. Bacterial absolute abundance was approximately 2.6-fold higher in inoculated plots, while fungal abundance declined, resulting in a substantially elevated bacteria-to-fungi ratio; community composition and diversity indices showed no significant changes. The inoculant strains were not detectably enriched at harvest, yet functional groups associated with nitrification, nitrogen fixation, and organic matter decomposition were consistently elevated and positively associated with reactive nutrient fractions. These results suggest that diazotrophic inoculants may promote yield through transient microbial community activation and nutrient form transformation rather than persistent colonization, and highlight the value of absolute quantification for detecting inoculation-induced shifts in microbial community size. Full article

Legume intercropping is a productive diversification strategy that can improve land-use efficiency and farm profitability, particularly for smallholders. However, its adoption remains limited in resource-intensive farming systems because crop-specific agronomic performance, input-use implications, and economic feasibility are not well documented under farmer-field conditions. This four-year field study (2021–2024) evaluated four sole cropping systems (sole cotton, sole maize, sole sugarcane, and sole soybean) and three additive soybean-based intercropping systems (cotton/soybean, maize/soybean, and sugarcane/soybean) under arid-irrigated conditions. Crop yield, dry matter accumulation, nutrient uptake, land equivalent ratio for land (LER_L), land equivalent ratio for nitrogen (LER_N), land equivalent ratio for phosphorus (LER_P), economic profitability, and labor requirement were assessed. On average, across the four study years, intercropped cotton, maize, and sugarcane produced 80%, 74%, and 88% of their respective sole-crop yields, while intercropped soybean produced 72%, 59%, and 83% of sole-soybean yield in cotton/soybean, maize/soybean, and sugarcane/soybean intercropping systems, respectively. At the system level, the total LER_L, LER_N, and LER_P values ranged from 1.33 to 1.71, 1.35–1.68, and 1.25–1.64, respectively, indicating resource-use (land and nutrients) advantages of intercropping compared with sole cropping. Based on these observed LER_N and LER_P values, soybean-based intercropping showed theoretical potential to reduce nitrogen and phosphorus fertilizer requirements by 26–40% and 20–39%, respectively; however, these estimates should be interpreted as potential input-economy indicators rather than experimentally validated fertilizer reductions. Economically, intercropping increased net income by ≈29–154% and generated 18–28% more labor demand than the corresponding sole systems, with sugarcane/soybean showing the highest net income (2937 USD ha⁻¹). Overall, additive soybean-based intercropping, particularly cotton/soybean and sugarcane/soybean systems with greater temporal niche differentiation, improved land productivity, nutrient-use efficiency indicators, and farm profitability under the tested arid-irrigated conditions. Further multi-location studies with actual reduced-fertilizer treatments are needed to validate fertilizer-saving potential and broader applicability. Full article

This article presents an experimental measurement scheme for direct current (DC) and alternating current (AC) magnetic fields based on optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in diamond. The work focuses on experimentally optimizing two established readout approaches on a custom platform rather than introducing a new ODMR mechanism. For DC magnetic field measurement, microwave frequency modulation combined with lock-in phase-sensitive demodulation is used to extract weak ODMR frequency shifts under magnetic-field perturbations. For AC magnetic field measurement, a Hahn echo quantum-control sequence is implemented, and the response of the NV centers to a 200 kHz AC signal is optimized by adjusting the free-evolution time. The results show that the platform can separately detect DC and AC magnetic fields with improved signal discrimination and robust responses under the tested conditions, providing experimental guidance for parameter selection in NV-center magnetometry. Full article

Accurate discrimination of multiple heavy metal ions is essential for environmental monitoring. This study developed a simple fluorescent sensing array utilizing carbon dots derived from black plum peels (PCDs) for the precise identification of metal ions in environmental waters. Three structurally distinct PCDs were hydrothermally synthesized using phenylenediamine isomers as nitrogen dopants, exhibiting distinct fluorescence response patterns to target ions. Pattern recognition was performed using linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA). The optimized system (pH 5–7) achieved high discrimination accuracy for eight metal ions (Sn²⁺, Ag⁺, Hg²⁺, Fe³⁺, Cr³⁺, Pb²⁺, Sb³⁺, and Cu²⁺) at 5–400 μM concentrations. The array effectively identified the binary and ternary mixtures of Hg²⁺/Cu²⁺/Cr³⁺ and successfully detected target ions in river water samples. This cost-effective and scalable approach demonstrates strong potential for applications in water quality monitoring and food safety. Full article

A sustainable method of improving soil fertility and developing climate-resilient cropping systems is vermicomposting agricultural waste. This study hypothesized that vermicompost derived from mixed organic agricultural wastes would significantly improve soil fertility, crop productivity, and drought resilience compared to single-substrate treatments and the unamended control. The effects of vermicompost generated from mixed organic wastes using Eisenia fetida on soil quality, crop performance, and drought resilience of lettuce (Lactuca sativa, Eden variety) were evaluated in this study using a randomized complete block design. Crop performance indicators included germination, growth characteristics, biomass, SPAD chlorophyll content, and yield, while soil physicochemical properties, including pH, organic carbon, total nitrogen, available phosphorus, exchangeable potassium, electrical conductivity (EC), and cation exchange capacity (CEC), were assessed both before and after amendment application. The effects of drought stress were evaluated using leaf surface temperature, wilting score, recovery time, and survival rate. The results demonstrated that vermicompost application significantly improved soil fertility and crop performance relative to the control treatment (p < 0.05). The best-performing treatment (T2) increased soil organic carbon by approximately 22–28%, total nitrogen by 18–24%, available phosphorus by 20–27%, and exchangeable potassium by 16–21% compared with the control. Fresh biomass increased by approximately 14–17%, marketable yield improved by 16–24%, and SPAD chlorophyll values increased by nearly 20%, indicating enhanced photosynthetic efficiency and nutrient uptake. T2 showed the most resilience under drought stress, with ~94.9% survival rate, reduced wilting severity, shortened recovery time and sustained stable leaf temperature (~27.8 °C), whereas low-performing treatments and the control recorded survival rates of only ~70–78%. Mixed organic waste substrates consistently outperformed single-substrate treatments, demonstrating synergistic effects on nutrient cycling, microbial activity, soil structural quality, and drought tolerance. These findings provide quantitative evidence that vermicomposting can simultaneously enhance soil fertility, crop productivity, and drought resilience, highlighting its strong potential as a scalable climate-smart strategy for sustainable agriculture, circular bioeconomy development, and organic waste valorization in smallholder farming systems. Full article

Nitrite (NO₂⁻) is a crucial environmental and food safety indicator, and excessive intake poses severe threats to human health; thus, highly sensitive and selective detection methods are urgently needed. Herein, a ratiometric fluorescent nanosensor based on N-CDs@UiO-66-NH₂ was constructed via a facile assembly strategy for sensitive and selective nitrite detection. The composite demonstrated dual-emission fluorescence at 456 nm and 730 nm under 365 nm excitation, originating from UiO-66-NH₂ and N-CDs, respectively, enabling an intrinsic self-referencing signal. The fluorescence intensity ratio exhibited a good linear response toward nitrite in the range of 10–100 μM and 100–450 μM with a limit of detection (LOD) 1.76 μM. The nanosensor showed high selectivity and anti-interference ability against various ions and molecules. Furthermore, it was successfully applied to nitrite detection in lake water samples with satisfactory recoveries (97–101%) and low relative standard deviations (<1.8%). This work provides a simple and effective approach for nitrite monitoring in environmental samples. Full article

Studies addressing seasonal changes in diet quality and hormones are important for understanding the interactions between ecology and physiology. We collected fecal samples from free-ranging adult female pronghorn (Antilocapra americana) to examine the relationships between indicators of nutrition and glucocorticoid activity. This occurred during three population-level, life-history-correlated sampling periods across five subpopulations. We evaluated nutrition via fecal nitrogen, fecal 2,6-diaminopimelic acid (DAPA), and assessed glucocorticoid activity using fecal glucocorticoid metabolites (FGM). We found positive relationships between fecal nitrogen and DAPA, whereas DAPA and fecal nitrogen with FGM varied in influence and strength, depending upon life history stage. Generally, correlations between DAPA and FGM were strongest during late gestation sampling, whereas correlations between those two measures and fecal nitrogen lacked consistency across life history stages and years. We found that maternal nutrition and stress were associated with notable changes in the relative intake of dietary protein from plant functional groups across sampling periods. Pronghorn appeared to shift between diets high in nitrogen or digestible energy content, depending upon life history stage and associated metabolic demands. We feel these results will assist wildlife managers in further understanding relationships between physiological parameters and how pronghorn meet the metabolic requirements of life history stages. Full article

The article investigates the role of carbon nanomaterials (CNMs), surface-oxidized carbon nanotubes (CNTs) and few-layer graphene fragments (FGFs), as well as FGFs hetero-doped with N and P atoms, as anticorrosive additives in industrial paints based on polyvinyl chloride. All CNMs were characterized by thermogravimetry, transmission electron microscopy, low-temperature nitrogen adsorption, and X-ray photoelectron spectroscopy. Corrosion resistance was determined using electrochemical tests and impedance spectroscopy. The surface and internal 3D structure of steel and coated steel were visualized using laser confocal microscopy and computed tomography. Coatings containing polyvinyl chloride with 0.05 wt% oxidized CNTs or FGFs show the highest electrochemical resistance and the best anticorrosive properties. The corrosion rate for coatings containing CNMs decreases by an average of 5–7 times compared to uncoated steel. It is shown that the improvement in anticorrosive characteristics is determined by the texture parameters and the composition of CNMs. The pores in CNMs act as a reservoir for the electrolyte and increase the corrosion rate. Oxygen-containing surface groups prevent corrosion by increasing the resistance of the materials. Full article