Search Results (9,115)

A novel acridine-based fluorescent sensor (Sensor ANT) for the highly selective and sensitive detection of cyanide ions (CN⁻) was rationally designed and synthesized via the conjugation reaction of acridine-9-amine with 3-nitrophenyl isothiocyanate. The sensing mechanism is triggered by the specific interaction between exogenous CN⁻ and the hydrogen-bonding moieties within the sensor’s molecular framework, which induces a distinct fluorescence quenching response. Systematic titration experiments confirmed that Sensor ANT exhibits rapid response kinetics, excellent selectivity, and reliable qualitative/quantitative detection capabilities toward CN⁻. Complementary biocompatibility assays, including in vitro cellular imaging and in vivo zebrafish experiments, further verified the promising application potential of this sensor in practical and biological detection scenarios. The detection limit (DL) of Sensor ANT for CN⁻ was calculated to be 2.89 × 10⁻⁷ M, with a 1:1 binding stoichiometry and a binding constant of 1.95 × 10⁴ M⁻¹. These findings demonstrate that Sensor ANT represents a robust candidate for CN⁻ detection in environmental and biological systems. Full article

Rural revitalization has emerged as a core agenda in the global pursuit of sustainable development, with its success fundamentally hinging on enhancing the resilience of rural households to withstand shocks and restore their livelihoods. In contrast to mainstream research that primarily examines whether Medical Financial Assistance (MFA) reduces medical burden, this paper focuses on MFA as ex-post cash compensation and investigates whether and how it affects the sustainable livelihood recovery of low-income rural households following health shocks, thereby providing empirical evidence for understanding the foundational role of health security in rural revitalization. A quasi-natural experiment is constructed by leveraging the institutional feature that MFA eligibility is activated by exogenous health shocks. Using two-wave balanced panel data (2021–2022) from a nationally designated deep poverty-stricken county in Hebei Province, China, the Propensity Score Matching–Difference-in-Differences (PSM-DID) method and mediation models are employed for causal identification and mechanism testing. The findings indicate that (1) MFA significantly promotes household income recovery. It enables recipient households to recover per capita net income by an average of approximately 13.2% (p < 0.01), demonstrating a protective recovery effect, and simultaneously recovers per capita non-farm labor income by an average of approximately 13.8% (p < 0.05), revealing a developmental recovery effect. The latter is partially mediated by the non-farm labor participation rate (mediation ratio 51.7%, Sobel Z = 2.10). This finding validates the “time release effect,” demonstrating that MFA stimulates endogenous dynamics by restoring health capital and releasing labor previously constrained by family care responsibilities. It thereby extends the application of health capital theory from the individual to the household level. (2) Mechanism analysis shows that the protective recovery effect is fully mediated by the amount of MFA received (mediation ratio 326.7%, Sobel Z = 12.85), providing empirical evidence for precautionary saving theory in the context of targeted social assistance and revealing the potential productive attributes of the social safety net. (3) Heterogeneity analysis reveals clear group targeting and shock thresholds. The protective effect is concentrated among elderly households, while the developmental effect is primarily evident in middle-aged households. Both recovery effects manifest significantly only for households experiencing major disease shocks, confirming the theoretical expectation of “conditional effectiveness,” namely that policy effects are systematically moderated by household life-cycle characteristics and the severity of health shocks. This study demonstrates that MFA serves both as a safety net and an empowerment tool, but its effectiveness is highly contingent upon household characteristics and shock severity. By uncovering the foundational mechanisms through which health security contributes to rural household resilience, this study provides empirical evidence from China for building sustainable poverty prevention systems in the global process of rural revitalization. Full article

The article presents the preliminary data from the excavation of the Azurrague 1 Dolmen (Ourém), carried out within the MEDICE II project, highlighting the importance of its location in a karstic landscape marked by a strong tradition of funerary cults in natural ca-vities. The dolmen structure features a heptagonal chamber and a short passage, with ri-tual deposits that include macrolithic tools, polished axes, ceramics, and human remains dated between the beginning of the Late Neolithic and the Middle Chalcolithic. The data indicates practices of secondary burial, continuity of regional lithic traditions, and a symbolic integration between exogenous architectural forms and endogenous ritual content established in caves. The proximity to caves with contemporary chronologies, such as Lapa da Furada, reinforces the coexistence of differentiated yet interconnected ritual spaces. Analogies with the Rego da Murta Megalithic Complex, caves and other sites in the Alto Nabão region support the hypothesis of a hybrid, long-lasting cultural system in which megalithic monumentalization is associated with ancestral symbolic practices. Full article

Sustainable agricultural techniques can ensure food security around the world. Hydrogel based soilless culture is an ecological and efficient alternative compared to conventional agriculture. Here, a multi-component hydrogel (pectin, Kelcogel, and chitosan/Se hydrogel, PKCH) was prepared by synthesizing natural biomolecules to cultivate dandelion for stimulate dandelion growth and improve nutritional value. The germination percentage of dandelion on PKCH (88.89%), was significantly higher than that in traditional hydroponics and pure Kelcogel (p < 0.05). Compared with hydroponics, the long-term dandelion cultivation experiments demonstrated that the PKCH cultivation mode enhanced root vitality, further increasing the growth and yield of dandelions (shoot length: 18.36 ± 0.30 cm, root length: 9.28 ± 0.21 cm, main root diameter: 0.94 ± 0.02 cm). The hydrogel substrate was associated with improved nutrient solubilization and sustained release, which may be linked to the accumulation of low-molecular-weight organic acids in the rhizosphere. Exogenous Se was effectively assimilated and transported to the above-ground parts of dandelion, which stimulated the photosynthetic efficiency and nutritional accumulation of dandelion. The polysaccharide content of dandelion reached 69.40 ± 0.13% (expressed as glucose-equivalent total sugars), which demonstrated the potential antioxidant properties and medicinal value. Technical economic analysis revealed the cost-effectiveness of PKCH synthesis and application. This study enriches the application of hydrogels in dandelion cultivation and provides an alternative approach for cultivating dandelion in soilless environments and medicinal crop production techniques. Full article

This study examines the impact of the Russia–Ukraine war on crude oil tail risk using the Conditional Autoregressive Value at Risk (CAViaR) framework. We analyzed 2364 daily observations of West Texas Intermediate (WTI) crude oil futures spanning 1 January 2015 to 11 December 2023, thereby capturing both the pre-war period and the conflict regime. To operationalize the geopolitical shock, we identify four theoretically grounded event dates (21 February, 24 February, 11 May, and 15 June 2022) associated with military escalation and energy-supply disruptions, and incorporate them as exogenous dummy variables. Methodologically, we implement a two-step approach. First, we estimate 1-day Value at Risk (VaR) at the 5% and 1% levels using four alternative CAViaR specifications (Adaptive, Symmetric, Asymmetric, and Indirect GARCH(1,1)) within a rolling-window framework to capture the dynamic evolution of tail risk. Second, we regress the resulting VaR series on geopolitical-event indicators to quantify the marginal effect of war-related developments on downside risk. The empirical results show tail risk increases in oil-market after the most important geopolitical events in all the model specifications across the market characteristics. The Indirect GARCH(1,1) CAViaR model exhibited the highest sensitivity, producing event coefficients of 0.795 (5% VaR) and 0.710 (1% VaR), both significant at the 1% level. Our adaptive specification has magnitudes that are even higher at the extreme tail (2.002 at 1% VaR), further supporting increased vulnerability during periods of escalation in conflict. Evidence from the asymmetric model would also indicate stronger market response to unfavorable news, in line with loss-sensitive investor behavior. In sum, the outcomes indicate that the Russia–Ukraine war considerably elevated the downside risk of crude oil markets and that geopolitical events have economically and statistically significant effects on the tail dynamics. Incorporating event-based geopolitical indicators in the framework of CAViaR, contributes to the literature in energy-market risk modeling and applies practical information to investors, risk managers, and policymakers operating under a dynamic environment characterized by geopolitical uncertainty. Full article

Thallium (Tl) contamination of soils in lead-zinc mining areas poses potential ecological risks, and the impact of microplastics on Tl accumulation by hyperaccumulator plants remains unclear. This study examined soils collected from the Daliangzi lead-zinc mining area to investigate the characteristics of Tl contamination. These soil samples were used in plant cultivation experiments. The thallium contents in both the soil and plant samples were determined using acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS). The contamination level, plant enrichment capacity, and ecological risk were then comprehensively evaluated through the Geo-accumulation index (I_geo), Bioconcentration factor (BCF), and potential ecological risk index. The results indicated that the I_geo of Tl in the soil was 2.413, corresponding to a moderately to heavily polluted level, which necessitates focused attention. Polyethylene exhibited markedly opposing effects on Pteris vittata and Solanum nigrum: it significantly promoted Tl accumulation in the former, while distinctly inhibiting it in the latter. Microplastics could modify the pH value of soil, as well as the contents of nitrogen (N) and phosphorus (P). Risk assessment indices indicated that Tl pollution in this region reaches a very high contamination level with moderate potential ecological risk. Polyethylene and polypropylene demonstrated a species-specific promoting effect on Tl adsorption by the two hyperaccumulator plants, with polyethylene significantly enhancing the Tl accumulation capacity of P. vittata and polypropylene distinctly promoting Tl adsorption in S. nigrum. Full article

Amid frequent external shocks and deepening market linkages, the information-transmission structure of financial markets is more prone to phase-specific abrupt changes, creating a need for real-time monitoring methods. This study develops an online framework to track financial information-flow networks and to provide early warnings of structural changes under exogenous shocks. Methodologically, information-flow networks are constructed from return spillovers using the Diebold–Yilmaz framework. An Exponential Random Graph Model is then employed to quantify how exogenous variables affect edge formation. Statistical process control methods, namely the Multivariate Cumulative Sum (MCUSUM) and Multivariate Exponentially Weighted Moving Average (MEWMA), are introduced to online monitoring of exogenous-effect coefficients. The simulation study uses simulated data to assess whether the two charts are properly calibrated and sensitive to alarms. The empirical study uses Shanghai Stock Exchange (SSE) 180 constituent stocks and exogenous variables—7-day Fixing Repo Rate (FR007), M2 growth rate (M2), the China Economic Policy Uncertainty Index (CEPU), and the Global Economic Policy Uncertainty Index (GEPU) over 2011–2025. The results indicate that both charts achieve the target in-control average run length, and detection accelerates with shock magnitude; FR007 is generally negative, M2 is positive, and uncertainty measures vary strongly over time; monitoring reveals shock clustering and long-term drift, implying both shock amplification and structural drift in the information-flow network. Practically, the framework provides an implementable warning tool for tracking shock amplification, supporting timely risk management. Full article

Water salinization severely limits agriculture in semiarid regions. This study evaluated the efficacy of exogenous carnitine (CAR) application in mitigating salt stress in two gherkin cultivars (Cucumis anguria L.), ‘Liso Gibão’ and ‘Do Norte’. The experiment used a randomized block design (3 × 3 factorial), combining three electrical conductivity levels of irrigation water (ECiw: 0.5, 2.5, and 4.5 dS m⁻¹) and three foliar carnitine concentrations (0.0, 0.5, and 1.0 mM). The results indicated that increasing ECiw to 4.5 dS m⁻¹ caused drastic reductions in growth, production, and photosynthetic efficiency, resulting in a 54.87% decrease in the number of fruits, due to toxic accumulation of Na⁺ and Cl⁻. However, carnitine supplementation (optimally at 0.5 mM) attenuated such damage, promoting significant increases in biomass (up to 55.43% for total dry mass), fruit number (by 23.37%), and gas exchange rates. The CAR application was associated with reduced Na⁺ accumulation (reducing leaf Na⁺ by 40.23% under moderate stress) and improved K⁺ and Ca²⁺ homeostasis. The cultivar ‘Do Norte’ showed higher carnitine-mediated tolerance, outperforming ‘Liso Gibão’. Carnitine acts as an effective biostimulant, with its application associated with improved ionic balance and gas exchange, supporting gherkin production under saline conditions. Full article

Citrulline (CIT), a natural non-protein amino acid and nitric oxide (NO) precursor, plays a vital role in plant physiological regulation. Its use as an eco-friendly biostimulant aligns with global efforts to reduce dependence on synthetic agrochemicals and strengthen sustainable crop production systems. This study represents the first report investigating the effects of exogenous citrulline (0, 0.5, and 1 mM) as a biostimulant/eustressor in two faba bean (Vicia faba) cultivars (Giza 843 and Sakha 1) and the first report to evaluate the variety and dose-dependent responses to foliar CIT application. The morphological, biochemical, and antioxidant responses were assessed. CIT significantly improved several growth and yield attributes in a cultivar-dependent manner, with Giza 843 performing best at 1 mM and Sakha 1 showing optimal shoot performance at 0.5 mM. CIT increased H₂O₂ levels, flavonoids, and catalase activity, which modulate the response mechanisms of treated plants of two varieties of faba bean. In contrast to Giza 843, Sakha 1 increased proline and the activities of peroxidase and ascorbate peroxidase, which is parallel with decreasing soluble sugars and proteins in response to CIT application. These results showed that Sakha 1 had more effective defense mechanisms than Giza 843. These findings demonstrate that CIT at an optimal dose is a promising, eco-friendly biostimulant. It may be suitable to integrate into sustainable crop management programs to enhance crop resilience and productivity. Full article

This study presents a comprehensive regional analysis of the COVID-19 pandemic’s impact on tourism in Slovakia during 2018–2024, employing rigorous statistical methods to quantify sectoral transformations. Based on extensive data on visitor arrivals, revenues, and accommodation facility utilisation across eight NUTS III regions, the analysis identifies four distinct regional tourism clusters characterised by differentiated recovery trajectories. Paired t-tests confirmed statistically significant changes in international tourist arrival indices across seven regions (p < 0.05), validating fundamental structural reorientation in tourism demand. The findings reveal pronounced heterogeneity in recovery patterns: while the Bratislava Region and the Žilina Region achieved substantial revenue growth (46.04% and 146.54%, respectively), domestically oriented regions (Banská Bystrica, Košice, Nitra, Prešov, and Trenčín) demonstrated minimal recovery (8.19% aggregate growth). Critical findings include the persistence of passive tourism dominance (94.09% of national revenues), declining international competitiveness from traditional Western European source markets, and compensatory expansion from emerging markets (USA +398.73%, Oman +234.68%, and Poland +226.55%). The ANOVA analysis revealed no statistically significant differences between regional indices in 2024 (p = 0.362), indicating market stabilisation despite differentiated trajectories. The study emphasises the necessity of regionally calibrated sustainable strategic interventions to diversify experiential tourism, activate the domestic market, and enhance technological infrastructure to build sectoral resilience against future exogenous shocks. Full article

Climate change is advancing ripening and can impair phenolic maturity in grapes, compromising anthocyanins and stilbenes that affect the wine color and stability. We tested whether exogenous abscisic acid (ABA) mitigates warming-induced shifts in the phenylpropanoid pathway in the ’Malbec’ red wine grape variety. A factorial field experiment compared control temperature (−T) and elevated temperature (+T, +2.5 °C), with and without ABA sprays (three applications after veraison). Berry skin gene expression (ten flavonoid and stilbene genes) was monitored across ripening and summarized using time-course and AUC-based clustering. Anthocyanins were quantified in berry skins at harvest and in the corresponding wines, and stilbenes were quantified in wines. Warming reduced MYBA1 early in ripening and decreased anthocyanins and stilbenes overall. Meanwhile, ABA reinforced a late anthocyanin program under −T (MYBA1, UFGT, MYBC2-L3, F3′5′H), consistent with a shift toward the 3′,5′-hydroxylated/malvidin-type branch. Conversely, stilbenes remained suppressed under +T, with limited recovery under +T/+ABA. Time-integrated expression patterns and Spearman correlations consistently linked CHS2, F3′5′H, UFGT, MYBC2-L3, with variation in berry skin anthocyanins across treatments, while STS AUC tracked wine stilbenes. Overall, ABA partially buffered warming effects on ‘Malbec’ color by reinforcing late anthocyanin regulation but did not prevent warming-driven declines in wine stilbenes. Full article

This paper investigates the optimal investment and reinsurance problem for insurers in a financial market with contagion risk. The prices of risky assets are assumed to follow a jump–diffusion model, where the jump component is driven by a multidimensional dynamic contagion process with diffusion (DCPD). This process simultaneously captures jumps triggered by endogenous and exogenous excitations, effectively characterizing the dynamic contagion effects arising from the joint influence of multiple factors in financial markets. The insurer aims to maximize a mean-variance (MV) utility function by purchasing per-loss reinsurance and investing the surplus in the contagion financial market. By solving the extended Hamilton–Jacobi–Bellman (HJB) equations, we derive the time-consistent equilibrium investment and reinsurance strategies, as well as explicit expressions for the equilibrium value function. These results are characterized by two nonlocal partial differential equations (PDEs), whose probabilistic solutions are obtained through the Feynman–Kac formula. Finally, numerical experiments illustrate how equilibrium strategies respond to changes in contagion intensity and confirm the effectiveness of the proposed model. Full article

This work examined the development of amylose–lipid complexes in green banana flour (Musa × paradisiaca) incorporated with virgin coconut oil (VCO), focusing on their spectral, thermal, and in vitro digestibility characteristics. Firstly, the native banana flour was analyzed for apparent amylose content using a spectrophotometric assay. To facilitate amylose–lipid complexation, both hot-pressed and cold-pressed VCO were incorporated into the banana flour under controlled thermal conditions, after which amylose–lipid interactions were characterized using Fourier-transform infrared and Raman spectroscopy for spectral features and differential scanning calorimetry for thermal behavior. The banana flour exhibited an AAC of 26.40 ± 0.002%. GCMS analysis of FAME derivatized VCO detected medium- to long-chain fatty acids, including octanoic (C8:0), decanoic (C10:0), dodecanoic (C12:0), tetradecanoic (C14:0), and hexadecanoic acids (C16:0) stearic acid (C18:0) and oleic acid (C18:1). FTIR coupled with multivariate analysis and Raman spectra confirmed lipid incorporation/retention in green banana flour through characteristic O–H, C–H, and C=O bands. While DSC revealed distinct endothermic transitions at 89.56 ± 2.17 °C (ΔHₘ = 0.8587 ± 0.1014 J g⁻¹) for hot-pressed VCO and 89.18 ± 0.98 °C (ΔHₘ = 0.6267 ± 0.0777 J g⁻¹) for cold-pressed VCO, consistent with the melting of V-type amylose–lipid complexes. Morphological analysis revealed that thermal treatment transformed native banana flour from irregular granular structures into an amorphous matrix via starch gelatinization, whereas subsequent incorporation of VCO promoted aggregation. In vitro enzymatic digestion showed a slight reduction in starch hydrolysis in VCO-treated samples. The incorporation of an exogenous lipid, such as VCO, into green banana flour promotes the formation of thermally stable amylose–lipid complexes that reduce enzymatic digestibility. Full article

The COVID-19 pandemic constitutes one of the most significant exogenous shocks to global financial markets in recent history, raising questions about the robustness of market efficiency under extreme uncertainty. This study examines whether the pandemic affected the weak-form efficiency of the Bitcoin market or merely heightened volatility without introducing return predictability. Using daily Bitcoin log returns from January 2013 to February 2026, the analysis first evaluates weak-form market efficiency through the Variance Ratio (VR) test. The VR statistics remain close to unity across multiple holding horizons, and the null hypothesis of a random walk cannot be rejected, indicating that daily Bitcoin returns are consistent with weak-form efficiency. Building on this baseline, an Interrupted Time Series (ITS) framework is employed to assess whether the onset of the COVID-19 pandemic in March 2020 led to structural changes in Bitcoin return dynamics. The ITS results reveal no statistically significant changes in level or slope following the outbreak. To further account for autoregressive and moving-average dynamics while explicitly modelling the intervention, an ARIMAX (0, 0, 7) model with COVID-19 intervention variables is estimated. Both the pandemic dummy and its interaction term are statistically insignificant, indicating no material change in the return-generating process after controlling for serial dependence. The moving-average structure indicates that shocks dissipate over approximately one trading week, consistent with weekly trading cycles and liquidity patterns in cryptocurrency markets rather than persistent return predictability. Diagnostic checks, including the Ljung–Box and Shapiro–Wilk tests, confirm the absence of residual autocorrelation and support the model’s white-noise properties. Although volatility increased during the pandemic period, daily Bitcoin returns continued to align with weak-form market efficiency. The evidence, therefore, suggests that COVID-19 served as a stressor without generating persistent inefficiencies. These findings reinforce the distinction between volatility and predictability, demonstrating that heightened uncertainty does not necessarily undermine informational efficiency. Full article

Cattle manure composting is an effective strategy for recycling agricultural waste. However, the presence of lignocellulosic materials in cattle manure–maize straw mixtures can limit the degradation efficiency during composting. This study investigated the effects of microbial inoculation on composting performance using three treatments: a lignocellulose-degrading microbial consortium (MC1), a commercial microbial inoculant (BS1), and a non-inoculated control (CK). The results showed that the MC1-treated pile entered the thermophilic phase (>50 °C) earlier than the BS1-treated pile. After 49 days of composting, the lignocellulose degradation rates in the MC1, BS1, and CK treatments were 46.25%, 37.5%, and 29.8%, respectively. Based on compost maturity indicators, including temperature, C/N ratio, pH, and electrical conductivity (EC), the composting period required to reach maturity was shortened by 8 days in the MC1 treatment compared with the BS1 treatment (37 vs. 45 days). Microbial community analysis indicated that MC1 inoculation increased the relative abundance of key microbial groups, particularly Ascomycota and Firmicutes, thereby enhancing lignocellulose degradation and accelerating composting. These findings provide insights into the application of lignocellulose-degrading microbial inoculants for improving cattle manure composting efficiency. Full article