Search Results (10,125)

The pronounced heterogeneity of high-Andean soils constitutes a critical constraint to the sustainable productivity of quinoa in southern Peru, where current yields (1.6 t ha⁻¹) remain well below potential (>5 t ha⁻¹). This study aimed to develop a spatially predictive model of a weighted soil quality index (SQIw), the edaphic supply of nitrogen (N), phosphorus (P) and potassium (K), and the agricultural gypsum requirement by integrating edaphoclimatic covariates through regression–kriging. A total of 198 quinoa-cultivated soil samples were analysed; a minimum data set (MDS) was defined using correlation and principal component analyses, and regression–kriging was applied to map SQIw and the variables of interest. The MDS comprised electrical conductivity (EC), organic matter (OM), available P, exchangeable Na, sand, clay, and effective cation exchange capacity (ECEC); exchangeable Na (Wi = 0.160) and available P (Wi = 0.158) received the largest weights in the SQIw. SQIw values ranged from 0.22 to 0.84 and supported a five-class soil quality taxonomy; spatial modelling revealed a dominance of moderate-quality soils across the territory (85.21% of the agricultural area, 13,461.19 ha). The model achieved R² = 0.56, RMSE = 0.05, and MAE = 0.04 for SQIw. Most of the area (12,175.65 ha; 77%) exhibited an intermediate gypsum requirement (9.73–14.33 t ha⁻¹). Nitrogen and phosphorus showed the greatest territorial limitations, whereas potassium was largely non-limiting (84.82–570.17 kg ha⁻¹). These results indicate that sodicity and N–P deficiencies are the primary functional constraints; the generated maps enable prioritisation of gypsum amendments and targeted variable-rate fertilisation strategies to optimise the sustainability of quinoa production in the Altiplano. Full article

The research focuses on the development of chemically bonded phosphate ceramics using potassium hydrophosphate and steel slag (EAF) as raw materials. The objective is to scale up the laboratory results to design a ceramic paste suitable for architectural monolithic products, promoting the recycling of EAF steel slag. The methodology includes field visits, grinding and sieving of raw materials, and the fabrication of specimens following ASTM standards. The laboratory results from existing studies on multiphase phosphate cements from steel slags indicate that exothermic reactions and the increase in reactants can affect process scaling. Furthermore, shaping methods such as casting and pressing are evaluated, where pressing proves to be the most suitable for this type of phosphate cement as it increases the material’s mechanical properties (compressive strength), reduces porosity, and generates a greater utilization of the EAF steel slag residue. Taking into account Colombian technical standards regarding the minimum compressive strength that a monolithic architectural object must withstand for structural and non-structural use, the results obtained in this research allow us to conclude that this material can indeed be used for architectural purposes. Full article

Water-In-Salt (WIS) electrolytes are expected to replace expensive, environmentally harmful organic electrolytes while delivering high voltages and improving system safety. In this study, analysis of the failure modes, mechanisms, and effects of a highly concentrated potassium acetate (KAc) electrolyte was conducted through electrolyte degradation at 2 V in a conventional EDLC carbon-based symmetric configuration. The adopted method provides a simplified yet effective approach for assessing the complexity and interconnectivity of degradation mechanisms in a WIS supercapacitor. The effects analysis included electrochemical stability studies, post-mortem characterizations (SEM-EDS and XPS), low-frequency impedance fitting, and cell reassembly using end-of-life electrodes. Among the failure modes analyzed, electrolyte decomposition and pore blocking exhibit strong physicochemical correlations and high failure rates. Therefore, they should be prioritized in the design of new WIS electrolyte compositions for next-generation energy storage systems. Full article

Myo-inositol (MI) is recognized as a potential stress regulator capable of alleviating abiotic stress. The objective of this study is to analyze the role of MI in the salt stress response of Daucus carota L. and its potential mechanisms. “Hongxin Qicun” carrot seedlings were subjected to five treatments: control; salt stress (50 mM NaCl); and salt stress combined with 50, 100, or 200 μM of MI. Through an integrated approach combining physiological assays, non-invasive micro-test technology (NMT), and gene expression profiling, we found that salt stress severely inhibited seedling growth, disrupted K⁺/Na⁺ homeostasis, and triggered excessive H₂O₂ accumulation. Exogenous MI application mitigated these salt-induced damages, with 100 μM MI exerting the optimal effect. MI enhanced Na⁺ efflux and reduced K⁺ efflux in carrot roots under salt stress. Inhibitor experiments indicated that MI-promoted Na⁺ efflux relies on active transport via the plasma membrane (PM) Na⁺/H⁺ antiporter system, and qRT-PCR analysis showed that this response was accompanied by the upregulation of DcSOS1. Furthermore, MI contributes to K⁺ homeostasis by synergistically modulating PM H⁺-ATPase and high-affinity potassium transporters. The established proton gradient helps reduce salt-induced K⁺ loss through depolarization-activated potassium channels and non-selective cation channels. MI treatment decreased electrolyte leakage, malondialdehyde content, and H₂O₂ accumulation by enhancing the activities of the plant antioxidant defense system. Meanwhile, MI upregulated the expression of myo-inositol oxygenase (DcMIOXs) genes, which may contribute to osmotic balance maintenance and facilitate ROS scavenging. In conclusion, exogenous MI alleviates salt-induced physiological disorders in Daucus carota L. by coordinately regulating K⁺/Na⁺ and ROS homeostasis, with 100 μM identified as the optimal concentration for this effect. Full article

Properties of composite materials with polymer matrix and inorganic filler are affected by preparation methods and starting components’ properties. For example, filler powder particle size distribution, phase composition and presence/absence of dopants can greatly affect properties of resulting composites. The present research attempts to clarify the influence of synthetic CaCO₃ powder properties on alginate/CaCO₃ composite material preparation process. Composite materials in the form of granules, networks and films were created from suspensions of synthetic powders of calcium carbonates CaCO₃ in aqueous solutions of sodium alginate. Powders of calcium carbonates CaCO₃ were synthesized from 0.5 M aqueous solutions of calcium chloride CaCl₂ and aqueous solutions of potassium K₂CO₃ (at molar ratio Ca/CO₃ = 1), sodium Na₂CO₃ (at molar ratio Ca/CO₃ = 1), and ammonium (NH₄)₂CO₃ (at molar ratios Ca/CO₃ = 1 and Ca/CO₃ = 0.5) carbonates. Phase composition of powder synthesized from CaCl₂ and K₂CO₃ was presented by calcite. Phase composition of powders synthesized from other soluble carbonates included calcite and vaterite. The powder preparation protocol excluded the stage of synthesized powder washing for by-product removal. This preparation protocol provided preservation of reaction by-product in the synthesized powder at a very low level. The presence of NH₄Cl as a reaction by-product even in small quantities can be taken as a reason for visually observed subsequences of cross-linking reaction at the stage of suspensions preparation. Aqueous solution of sodium alginate and suspensions containing powders synthesized from potassium K₂CO₃ and sodium Na₂CO₃ carbonates demonstrated similar dependence of viscosities from shear rate. The presence of (NH₄)₂CO₃ in the powder synthesized at molar ratio Ca/CO₃ = 0.5 was the reason for the lower viscosity of the suspension in comparison with suspensions loaded with powders containing KCl, NaCl and (NH₄)₂Cl as reaction by-products due to decomposition of unstable (NH₄)₂CO₃ and gas phase formation. The presence of (NH₄)₂Cl in the powder synthesized at molar ratio Ca/CO₃ = 1 in contrast was a reason for the highest viscosity suspension in comparison with those under investigation. Additionally, (NH₄)₂Cl presence in synthetic powders shows the ability to facilitate partial dissolution of CaCO₃ providing a higher concentration of Ca²⁺ cations at the stage of suspension preparation, thus aiding the cross-linking process of alginate hydrogel. Granules, meshes and films were created via interaction of suspensions of calcium carbonates CaCO₃ in aqueous solutions of sodium alginate with 0.25 M aqueous solutions of calcium chloride CaCl₂ to provide the formation of matrix of composites via Ca-crosslinking of sodium alginate followed by washing and freeze drying under deep vacuum. The created composite materials in the form of granules, meshes and films based on Ca-cross-linked alginate and powders of synthetic calcium carbonate can be recommended for skin wound and bone defect treatment and drug delivery carriers. Full article

Background/Objectives: Diuretics are recommended for hemodynamically stable patients with COVID-19-associated acute respiratory distress syndrome (ARDS) who have a positive fluid balance. However, furosemide use may be limited by hypokalemia in this population. We aimed to evaluate the clinical and biochemical effects of spironolactone in critically ill patients with COVID-19-associated ARDS. Methods: In this retrospective cohort study, 60 patients with COVID-19-associated ARDS admitted to the intensive care unit (ICU) between March and May 2020 were grouped according to diuretic therapy (furosemide vs. spironolactone). Patients were followed for five days (T0–T4). Demographic characteristics and clinical/laboratory parameters were recorded. A two-sided p value < 0.05 was considered statistically significant. Results: Thirty-one patients received furosemide (F group) and 29 received spironolactone (S group). On day 5, in the F group, cumulative fluid balance and serum sodium increased significantly over time (p < 0.05). Lactate increased significantly over time in both groups (p < 0.05). N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels increased significantly from T0 to T4 in the F group (p < 0.05). Conclusions: Spironolactone use was associated with a more favorable trajectory of organ dysfunction and improved volume, electrolyte, and cardiac stress marker dynamics compared with furosemide in patients with COVID-19-associated ARDS. Although confirmation in larger prospective studies is needed, spironolactone may be considered a reasonable diuretic alternative in selected patients, particularly when potassium preservation and avoidance of hypernatremia are clinical priorities. Full article

This study was conducted in the Xinjiang region, China, along the Sino-Kazakh border, an area recognized as high-risk for locust outbreaks and characterized by ongoing shifts in dominant pest species. This study systematically examined the structural characteristics of locust communities across different grassland types and identified the underlying environmental driving mechanisms. Field surveys were conducted to assess the diversity characteristics, density variations, and niche width of the locust communities across the different grassland types. The locust community in the mountain meadows had a significantly lower Shannon diversity index compared with the other grassland types (p < 0.05). Although the Simpson dominance index and Pielou evenness index were also the lowest in the mountain meadows, these differences were not statistically significant (p > 0.05). Permutational multivariate analysis of variance (PermANOVA) revealed highly significant differences in locust density among the grassland types (p = 0.001). Ecological niche analysis revealed stronger interspecific competition in the lowland meadow, and weaker competition in the temperate steppe-enriched deserts and temperate desert grasslands. Structural equation modeling and random forest analysis identified soil organic, plant total potassium, and soil pH as the key factors driving locust community structure across grassland types. This study clarifies the diversity patterns of locust communities in the Xinjiang region along the Sino-Kazakh border and provides empirical data to better understand locust community structure and distribution. It also offers a scientific basis for developing sustainable locust management strategies. Full article

Aquaponic systems are among the sustainable approaches for combining fish farming and plant cultivation and have been proposed as potentially economically viable food production technologies. Their performance depends on the balanced environmental conditions shared by fish, nitrifying bacteria, and plants. This study assessed the performance of a trout-based (Oncorhynchus mykiss) decoupled aquaponic system for basil (Ocimum basilicum L.) growth and essential oil composition. Two cultivation strategies were compared over 60 days: a non-supplemented system relying exclusively on trout rearing water, and a system supplemented with mineral nutrients formulated according to the recommendations of the Hoagland nutrient solution. Basil grown without mineral supplementation maintained a healthy appearance and stable physiological status, with satisfactory growth, although it remained lower than in supplemented plants. The mineral profile of the plants showed similar nitrate and phosphorus concentrations between non-supplemented and supplemented plants, with nitrate levels of 5.40 ± 0.29 mg g⁻¹ and 5.52 ± 0.29 mg g⁻¹, respectively, and phosphorus levels of 5.46 ± 0.23 mg g⁻¹ and 6.14 ± 0.91 mg g⁻¹, respectively. In contrast, potassium concentration was lower in non-supplemented plants (36.89 ± 3.31 mg g⁻¹) compared to supplemented plants (55.56 ± 7.16 mg g⁻¹). Essential oil yield expressed per cultivated surface area remained comparable between systems, reaching 2.96 and 3.09 mL m⁻² in the supplemented and non-supplemented systems, respectively. GC–MS analysis revealed that linalool (≈24%) was the predominant compound in both systems. Notably, estragole content was higher in non-supplemented plants (21.35 ± 1.46%) compared to supplemented plants (5.24 ± 0.68%). Overall, trout-based aquaponic systems not only support satisfactory basil growth but also enhance the production of essential oils with desirable aromatic characteristics, representing a sustainable and efficient strategy for aromatic plant cultivation. Full article

Background: We evaluated the association between admission serum glucose-to-potassium ratio (GPR) and injury severity as well as early transfusion requirements in patients with traumatic pelvic fractures. Methods: This single-center, retrospective cohort study included 84 adult patients with isolated or predominantly pelvic fractures admitted between January 2020 and December 2024. Patients with concomitant non-pelvic skeletal fractures were excluded to isolate the metabolic response attributable to pelvic injury. GPR was calculated from admission serum glucose and potassium levels. Higher transfusion requirement (HT) was defined as ≥4 units of packed red blood cells within 24 h. Receiver operating characteristic (ROC) analysis identified the optimal GPR cut-off using the Youden index. Internal validation was performed using bootstrap resampling (1000 iterations), and model calibration was assessed with the Hosmer–Lemeshow test. The incremental discriminatory value of GPR beyond the Injury Severity Score (ISS) was evaluated by comparing AUC values using the DeLong test, and reclassification metrics including the category-free net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated. Sensitivity analyses were conducted using alternative transfusion thresholds (≥6 and ≥10 units). Results: The optimal GPR cut-off was 34 (area under the curve (AUC) = 0.730; 95% CI: 0.593–0.853; sensitivity 78.8%; specificity 59.0%). Patients with GPR ≥ 34 (n = 43) had significantly higher ISS values (median 25 [IQR: 16–34] vs. 9 [5–17]; p < 0.001), greater transfusion volumes (median 3 [0–6] vs. 0 [0–1] units; p < 0.001), and longer intensive care unit (ICU) stays (3 (0–6) vs. 0 (0–1) days; p < 0.001). In univariable logistic regression, GPR was significantly associated with HT (OR = 1.059 per unit increase; 95% CI: 1.015–1.104; p = 0.008); however, significance was not retained in the multivariable model after adjustment for ISS (p = 0.194). ISS remained the sole independent predictor (OR = 1.128; p < 0.001). The combined ISS + GPR model yielded an AUC of 0.857, representing a modest increment over ISS alone (AUC = 0.849; ΔAUC = 0.009; DeLong p = 0.566). Bootstrap-corrected AUCs confirmed minimal optimism (GPR alone: 0.726; ISS + GPR: 0.847). The Hosmer–Lemeshow test indicated adequate calibration for all models (p > 0.05). The category-free NRI was 0.627 (p = 0.009), whereas the IDI did not reach significance (0.017; p = 0.290). Sensitivity analysis at the ≥6-unit threshold yielded consistent results (GPR AUC = 0.709). Conclusions: Admission GPR is significantly associated with injury severity, hemorrhagic burden, and transfusion requirements in patients with traumatic pelvic fractures. Although GPR does not independently predict transfusion needs beyond ISS, it yields significant reclassification improvement and may serve as a practical, rapidly obtainable adjunct for early risk stratification in the acute trauma setting. Level of Evidence: III (retrospective prognostic study). Full article

The market value of fragrant rice is largely defined by the presence and intensity of its aroma, which is primarily attributed to volatile compound 2-acetyl-1-pyrroline (2-AP). The biosynthesis of 2-AP is chiefly governed by recessive alleles of the badh2 gene. Nevertheless, 2-AP accumulation is also profoundly shaped by environmental factors and agronomic management. Field practices—such as balanced nitrogen and potassium fertilization, supplementation with trace elements, and application of plant growth regulators like methyl jasmonate—promote 2-AP synthesis by increasing precursor availability and enhancing the activity of key enzymes. Additionally, tillage systems, alternate wetting and drying irrigation, optimal planting density, and harvest timing significantly affect aroma quality. Abiotic stresses, including moderate drought, salinity, optimal temperatures around 25 °C, and low light during grain filling, can also stimulate 2-AP accumulation, often through shifts in proline metabolism and activation of stress-responsive pathways involving GABA and methylglyoxal. Despite the promise of these strategies, several challenges persist, such as the common trade-off between yield and aroma intensity, complex genotype-by-environment interactions, and incomplete elucidation of the molecular mechanisms involved. Moving forward, integrating multi-omics analyses with smart agriculture technologies will be essential to unravel the regulatory networks underlying aroma formation and to advance the breeding of high-yielding fragrant rice varieties with stable aroma traits under changing climate scenarios. Full article

Elemental migration and enrichment are important processes influencing tea plant growth and the assembly of rhizosphere bacterial communities within the rock–soil–plant continuum. This study explores how soil parent materials (granite, quartz schist, and sericite schist) are potentially associated with these processes and their observed associations with the elemental composition of tea leaves. Exploratory statistical analyses revealed distinct, lithology-specific biogeochemical patterns that serve as a foundation for hypothesis generation. In granite soils, chlorite correlated with the mobility of Cr, Pb, Cu, Ni, Mg, and Na, coinciding with shifts in the relative abundances of Verrucomicrobia, Armatimonadetes, and Chloroflexi. In quartz schist, kaolinite exhibited notable correlations with the dynamics of Pb, Cr, Ni, Zn, and As, which were statistically linked to Planctomycetes, Proteobacteria, and Acidobacteria. Complex mineral–microbe interactions were observed in sericite schist soils, where clay minerals (e.g., chlorite, illite) were closely associated with the migration of multiple elements (Pb, K, Ca, Cd, As, Al, Fe, Zn), paralleling structural variations in communities of Actinobacteria, Planctomycetes, Chloroflexi, and Proteobacteria. Potassium (K), calcium (Ca), and manganese (Mn) showed bioaccumulation tendencies in tea leaves across all lithologies, with an enrichment capacity order of Ca > K > Mn > Mg > Na > Al. Exploratory Classification and Regression Tree (CART) analysis suggested that the migration of K, Ca, Cu, Zn, and Hg corresponded most closely with their soil concentrations. Manganese (Mn) exhibited a mineral-associated trend, with kaolinite content as a potential correlate, while cadmium (Cd) migration was statistically linked to the relative abundance of Armatimonadetes. These findings highlight potential candidate relationships between mineralogy, microbes, and elemental mobility rather than confirming causal mechanisms, emphasizing the need for further validation in larger or experimental datasets. Full article

Saline–alkali soils suffer from severe deficiencies in available phosphorus, and externally added phosphorus is readily immobilized by metal ions in the soil. Therefore, activating inorganic phosphorus in the soil represents a significant challenge. In this study, 35 salt–alkali-tolerant bacteria were isolated from rhizosphere soils (pH 9.20–9.68). Three phosphate-solubilizing strains (HA2, HPA5, and KA1) capable of growing under severe saline–alkali stress conditions (pH 10, 5% NaCl) and possessing multiple plant growth-promoting traits (nitrogen fixation, potassium solubilization, siderophore production, and IAA secretion) were screened and co-cultured to form the microbial consortium HHK. It was hypothesized that this consortium might exhibit synergistic effects, resulting in significantly higher phosphorus solubilization capacity compared to individual strains. The results showed that under saline–alkali stress, the phosphate solubilization capacity of HHK (484.59 ± 15.79 mg/L) was significantly higher than that of any single strain (285.59 ± 12.60 mg/L). Non-targeted metabolomics and enzyme assays indicated that HHK solubilizes P via organic acids (e.g., citric, L-malic acid) and synergistically modulates core metabolic pathways, including ABC transport, TCA cycle, and glycolysis, alleviating oxidative damage and maintaining cellular homeostasis. Short-term soil incubation confirmed that HHK significantly increased available phosphorus (53.67%) and soil fertility, indicating its potential as a biofertilizer. Full article

This study employs a Computational Fluid Dynamics (CFD) approach based on the Two-Fluid Model (TFM) to investigate the CO₂ capture characteristics in a bubbling fluidized bed reactor using potassium carbonate (K₂CO₃) as the sorbent. The simulations are conducted at five superficial gas velocities ranging from 1.5 to 3.5 times the minimum bubbling velocity (u_mb = 0.26 m/s), with a particle diameter of 0.4 mm, particle density of 2300 kg/m³, and an initial solid volume fraction of 0.55. The gas mixture consists of CO₂, H₂O, and N₂ at a molar ratio of 0.1:0.1:0.8 and a temperature of 343 K. First, the numerical simulation was validated against experimental data reported in the literature, confirming its accuracy in quantitatively describing the adsorption process. Subsequently, the distributions of CO₂ concentration and adsorption reaction rate in both the bubble phase and the emulsion phase were analyzed under different superficial gas velocities. The simulation results indicate that CO₂ concentration and adsorption reaction rate in both phases decrease along the bed height. Compared to the emulsion phase, the bubble phase exhibits higher CO₂ concentration and gas temperature but a lower adsorption reaction rate. As the gas velocity increases, CO₂ concentration rises in both the bubble and emulsion phases, accompanied by an increase in the proportion of the bubble phase, and a higher CO₂ concentration at the reactor outlet. Further comparison of CO₂ concentrations in the bubble and emulsion phases at the upper part of the bed with the outlet concentration reveals that the outlet CO₂ primarily originates from the unadsorbed portion within the bubble phase, while the contribution from unadsorbed CO₂ in the emulsion phase is almost negligible. Full article

Potassium (K⁺) is a vital macronutrient for plant growth and stress resilience, with KT/HAK/KUP transporters playing a central role in its homeostasis. Although these transporters are known to influence photosynthesis, the molecular mechanisms by which fertilization promotes assimilate accumulation in peach crops remain poorly understood. In this study, 17 PpHAK genes were identified based on the peach genome and classified into four distinct clades through phylogenetic analysis, a classification further supported by conserved gene structures and motifs. Interspecific collinearity analysis revealed that transporters are highly conserved among Rosaceae species. Physiological measurements demonstrated that foliar application significantly enhanced photosynthetic capacity, as evidenced by a 33% increase in net photosynthetic rate (Pn) and improved photoelectron yield (Y(II)). At the same time, the transcript levels of the transporters PpHAK1, PpHAK5, and PpHAK9 were significantly upregulated, as confirmed by quantitative real-time RT-PCR (qRT-PCR) analysis. Furthermore, the expression of genes involved in sugar metabolism and transport, particularly PpPLT5-1, was significantly induced. Collectively, these results indicate that foliar K⁺ application enhances photosynthesis and promotes assimilate accumulation by modulating the expression of both K⁺ and sugar transporters. These findings offer a theoretical basis for optimizing nutrient management to improve fruit quality in stone fruit production. Full article

A new universal construction of intermediate-layer-free solid-contact ion-selective electrodes using a novel inner electrode, namely microelectrodes array composed of a large number of individual microelectrodes, was developed. This approach eliminates the need for a conventional solid-contact intermediate layer while maintaining excellent electrochemical performance. The studies were performed on two membrane model systems: potassium-ion-sensitive membranes based on valinomycin and nitrate-ion-sensitive membranes based on tridodecyldimethylammonium nitrate. In both cases, the membrane was applied directly onto the surface of the electrode substrate. The obtained results with such an ion-selective electrode based on a gold microelectrode array (GMA), a glassy carbon electrode (GCE), and a gold electrode (GE) were compared. It has been proven that, despite the lack of solid contact, whether in the form of an intermediate layer or as an addition directly to the membrane, ion-selective electrodes based on gold microelectrode arrays were characterized by very good analytical parameters. For those electrodes, a notable improvement in stability, reversibility, and repeatability of the electrode potential was observed and compared with electrodes using a glassy carbon disc electrode or a gold disc electrode as the electrode substrate. Thanks to the use of such an innovative electrode substrate, the final sensor preparation is shortened and simplified while maintaining good performance and stable readings. Full article