Search Results (954)

The purpose of this research is to investigate the potential of aromatic coconut waste-derived biochars, namely coconut husk biochar (CHB) and coconut empty fruit bunch biochar (CBB), as low-cost, sustainable, and locally available adsorbents. Biochars were characterized using SEM, XRD, XPS, and XRF to evaluate their physical and chemical properties, followed by CO₂ uptake, moisture uptake, and methylene blue (MB) adsorption experiments. The results demonstrated that CBB exhibited the highest CO₂ uptake of 4.44 mmol g⁻¹, outperforming CHB (2.39 mmol g⁻¹) under temperature-programmed desorption. Notably, the water-washed biochar (CBB-w) exhibited a marked decrease in CO₂ uptake, providing strong supporting evidence that naturally occurring mineral species play an important role in the CO₂ adsorption mechanism. The quantity and type of naturally occurring potassium-containing oxides and salts strongly influenced CO₂ and moisture uptake. In contrast, isotherm analyses using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models indicated that CHB exhibited a superior MB adsorption capacity (30 mg g⁻¹), reflecting the different adsorption mechanisms governing gas- and liquid-phase adsorption. The estimated production cost of aromatic coconut waste-derived biochar ranged from approximately US$0.83–1.11 kg⁻¹, depending on production scale. These results demonstrate that aromatic coconut waste-derived biochar represents a promising low-cost and sustainable adsorbent for environmental applications, particularly CO₂ capture and dye removal. Full article

Potassium (K⁺) is an essential mineral element for plant growth and development. Members of the HAK/KUP/KT (HAK) gene family serve pivotal roles in K⁺ uptake, translocation and homeostasis. Although numerous HAK genes have been extensively identified across diverse plant species, a comprehensive genomic and functional analysis of this family in sweet potato (Ipomoea batatas L.) remains lacking. In this study, 22 putative IbHAK genes were identified and classified into four distinct clades (I–IV). A systematic characterization was performed for each IbHAK gene, including protein physicochemical properties, chromosome distribution, gene structure, synteny, and promoter cis-elements. Notably, five IbHAK5 genes (IbHAK5A–IbHAK5E) clustered on the HAK gene tree with AtHAK5, OsHAK5, and ZmHAK5. This suggests that small-scale duplication events likely drove the expansion of HAK5 in sweet potato. Among them, IbHAK5A, a gene with broad expression across tissues and strong transcriptional induction under low-K⁺ (LK) stress, was cloned. The function was then characterized in a K transporter-deficient yeast mutant and an Arabidopsis hak5 mutant. Transcription factor IbPTL1 directly binds the IbHAK5A promoter, upregulates its expression, and integrates into the K⁺ signaling. In this work, we provide foundational insights into the underlying molecular mechanisms governing K⁺ acquisition in sweet potato. Full article

The prevention of coal mine fires and the sequestration of CO₂ represent two grand challenges that have traditionally been addressed separately. Here we report a CO₂-modified bentonite-based sealing material that concurrently achieves fire resistance, gas sealing and mineral-carbonation CO₂ uptake through rational materials engineering. In this work, “carbon-negative” is used as a comparative property: the material’s cradle-to-gate embodied emissions combined with its measured 28-day mineral uptake are lower than the cradle-to-gate footprint of a conventional cement-based benchmark under the stated system boundary. High-pressure CO₂ intercalation expanded the montmorillonite d-spacing from 12.48 to 14.79 Å and introduced carbonate functional groups (1435 cm⁻¹), as confirmed by FTIR and XRD. Systematic optimization of a bicomponent formulation incorporating municipal solid waste incineration slag and CO₂-saturated zeolite yielded a material with 28-day compressive strength of 37.9 MPa, a fire resistance limit of 186 s and O₂ reduction from 13.7% to 4.9%. Notably, carbon sequestration reached 24–40 kg CO₂ per ton through mineral carbonation, validated by carbonate peaks in FTIR and calcite detection in XRD. Carbon accounting based on a cradle-to-gate inventory (342–408 kg CO₂-eq/t) combined with the measured 28-day mineral uptake (24–40 kg CO₂/t) yields a comparative net balance of −46 to −188 kg CO₂-eq/t relative to a conventional cement-based benchmark under the stated system boundary. The synergistic mechanism involves CO₂-modified bentonite-regulating layer spacing, alkali-activated slag releasing Ca²⁺/Mg²⁺ for carbonate precipitation, and zeolite providing endogenous carbon slow-release. This work establishes a materials-chemistry paradigm for transforming industrial waste streams into functional carbon sinks while addressing critical mining safety needs. Full article

Coal-based solid-waste binders provide a promising route for integrating mine backfilling with CO₂ mineralization, but auxiliary components can affect flowability, strength, and mineralization response differently. In this study, coal gasification slag (CGS) and ground granulated blast-furnace slag (GGBS) were used as the base binder, while soda residue, carbide slag, phosphogypsum, desulfurization gypsum, and red mud were introduced as functionally distinct auxiliary components. The binders were subjected to CO₂ injection mixing, and their flowability, compressive strength, apparent CO₂ uptake, reaction products, and pore-related characteristics were evaluated. The response to CO₂ treatment depended strongly on the auxiliary–component combination. CO₂ injection mixing reduced the early-age strength of most formulations. In contrast, the carbide slag–red mud formulation, CGS9, showed favorable compatibility between cementitious reactions and mineralization. Its 3 d and 7 d strengths increased by 36.0% and 14.4%, respectively, while its 28 d strength remained nearly unchanged. Its apparent CO₂ uptake and carbonation degree reached 3.825% and 13.46%, respectively. XRD showed stronger calcite diffraction peaks after CO₂ injection mixing, while FTIR showed enhanced carbonate absorption bands. SEM-EDS and LF-NMR indicated matrix densification and refinement of the water-filled pore environment. These findings show that functionally distinct auxiliary solid wastes can help coordinate cementitious reactions and CO₂ mineralization, providing a feasible route for producing low-carbon mine backfill materials from coal-based solid wastes. Full article

Accurately characterizing crop–soil nitrogen dynamics is essential for precision nitrogen management in maize production, yet soil mineral nitrogen (soil N_min) remains difficult to monitor under field conditions. This study evaluated whether UAV-derived maize canopy traits could be used to indirectly estimate soil N_min in black soils through a cascaded modeling framework. Multi-stage UAV multispectral observations, agronomic variables, and machine learning were integrated into a cascaded framework in which aboveground nitrogen uptake (ANU) was first predicted and then used as an intermediate variable for soil N_min and yield estimation. UAV-derived vegetation indices showed stronger relationships with ANU than with soil N_min across growth stages, indicating that canopy spectral signals more directly reflected plant-level nitrogen accumulation. XGBoost achieved the best performance for ANU and soil N_min prediction, with R² values of 0.94 and 0.82, RMSE values of 15.99 kg ha⁻¹ and 6.42 mg kg⁻¹, and rRMSE values of 13.4% and 17.6%, respectively. Predicted ANU was the most influential variable for soil N_min estimation, and the framework also captured the nitrogen response pattern of yield. These results indicate that UAV-based canopy sensing can support the indirect estimation of soil N_min through crop nitrogen status, as well as nitrogen response diagnosis and data-informed nitrogen management in maize production. Full article

Iron (Fe) is an essential micronutrient for plant growth, serving as a cofactor in chlorophyll synthesis, photosynthetic electron transport, and redox reactions. Both Fe deficiency and excess disrupt mineral nutrient homeostasis, but the ionomic and transcriptomic mechanisms underlying genotype-specific responses in potato remain elusive. We profiled the ionome and transcriptome of two potato genotypes, 05P and CI5, grown under Fe-deficient, Fe-sufficient and Fe-excess conditions represented by 1, 40.4 and 120 mg L⁻¹ FeNaEDTA, respectively. Ionomic analysis detected significant alterations in Fe, Mn, Zn, Ca, Mg, and Cu concentrations across roots, stems, and leaves, with the direction and magnitude of change varying by organ and genotype. Under Fe deficiency, CI5 showed steeper declines in root and stem Fe than 05P, while 05P retained higher leaf Fe, reflecting genotype-dependent patterns of shoot Fe distribution. Fe excess caused Fe accumulation in both genotypes, but coincided with Mn depletion in shoots, raising Fe/Mn ratios, consistent with potential antagonistic Fe–Mn interactions at the transport level. This pattern is consistent with potential antagonistic Fe–Mn interactions, although alternative mechanisms such as Mn uptake inhibition or dilution effects cannot be ruled out without direct experimental evidence. Transcriptome analysis showed organ-biased responses: Fe deficiency upregulated more genes in stems, whereas Fe excess triggered stronger transcriptional shifts in roots. No KEGG pathways remained significant after false discovery rate (FDR) correction, suggesting that genotype-dependent Fe-responsive divergence was not concentrated in a limited number of canonical KEGG pathways under the present analytical framework. Joint analysis of ionomic and transcriptomic data highlighted ferric-chelate reductase oxidase (FRO) and zinc-regulated transporter/iron-regulated transporter-like protein (IRT/ZIP) family members as genes associated with Fe reduction, divalent metal uptake, and Fe–Mn balance based on differential expression and orthology with functionally characterized Arabidopsis homologs. Comparative genomics showed that FRO and ZIP families have expanded in potato, with conserved domain architectures but divergent gene structures and promoter architectures, consistent with potential functional diversification related to metal transport. In conclusion, under Fe deficiency, genotype-dependent transcriptional divergence was most pronounced in stems, whereas under Fe excess it was more evident in roots, jointly maintaining systemic Fe–Mn homeostasis in potato. Full article

Permafrost peatlands in high-altitude regions store substantial amounts of organic carbon, yet the biogeochemical consequences of thermokarst collapse remain poorly understood. Using a space-for-time substitution approach, we selected four habitats representing a thermokarst development sequence in the Altai Mountains peatlands—slightly collapsed peat mounds (P1), severely collapsed peat mounds (P2), thawed herbaceous peat (PB1), and thermokarst ponds (PB2)—and conducted in situ greenhouse gas flux monitoring, soil physicochemical analysis, enzyme activity assays, and structural equation modeling. We found that thermokarst development fundamentally altered the greenhouse gas source–sink balance through three interconnected mechanisms. First, CO₂ fluxes shifted from net emission in P1 (684.1 mg m⁻² h⁻¹) to net uptake in PB2 (−25.6 mg m⁻² h⁻¹), driven primarily by the oxidative loss of mineral-associated organic carbon in the 40–60 cm layer (71.3% loss), whereas lateral dissolved organic carbon export accounted for only 12.3% of total carbon loss. Second, CH₄ fluxes in PB2 (3.8 ± 0.7 mg m⁻² h⁻¹) reached approximately 43% of the theoretical maximum, with this suppression associated with phosphorus limitation (total phosphorus < 0.05 g kg⁻¹) and a marked reduction in alkaline phosphatase activity. Third, N₂O uptake increased along the thaw sequence to −28.6 μg m⁻² h⁻¹ in PB2, with the 40–80 cm layer contributing 42% more than the surface layer. This increase in N₂O uptake occurred when the soil C/N ratio exceeded 300, a threshold that reflects the substantial stoichiometric imbalance between carbon and nitrogen following thermokarst development. These findings demonstrate that the transition from peat mounds to thermokarst ponds alters the net greenhouse gas source–sink balance through changes in MAOC stability, phosphorus availability, and carbon-to-nitrogen stoichiometry. Our results provide empirical constraints for evaluating carbon-climate feedbacks in cold-region peatlands. Full article

To investigate the effects of red–blue–green light ratios on the growth, photosynthesis, nutritional quality, and mineral nutrient accumulation of hydroponic lettuce, a controlled experiment was conducted using the deep flow technique (DFT) system. Four light treatments were applied under a constant photosynthetically active radiation of 350 μmol·m⁻²·s⁻¹: the red–blue light control (CK, R:B = 60:40) and 10% (T1), 20% (T2), and 40% (T3) green light substitution treatments. Growth, photosynthetic characteristics, quality and nutrient indexes were assessed. The results showed that 40% green light (T3) significantly enhanced biomass production, increasing the fresh and dry weights by 33.16% and 21.40%, respectively, compared with the CK (control). In addition, the soluble sugar and vitamin C contents increased by 61.79% and 13.43%, respectively, while the nitrate content decreased by 16.31%. T1 (10% green light) was the most effective at promoting antioxidant compound accumulation, resulting in 148.61% and 81.24% increases in the flavonoid and polyphenol contents. All green light treatments increased the net photosynthetic rate and transpiration rate while decreasing the intercellular CO₂ concentration and stomatal conductance. Green light supplements generally promoted phosphorus and magnesium uptake, and T3 remarkably enhanced the total accumulation of major mineral elements in shoots. In conclusion, 40% green light substitution optimizes both the biomass and nutritional quality of lettuce, whereas 10% substitution significantly promotes antioxidant accumulation. These findings provide valuable insights for optimizing light spectra in controlled environments for hydroponic lettuce production. Full article

Sand enteropathy describes pathophysiological conditions of the equine gastrointestinal tract due to the uptake and accumulation of sand. It is an increasingly recognized cause of gastrointestinal disease in arid geographic areas. Clinical signs can vary widely from colic, fever and inappetence to poor performance. Diagnosis based solely on clinical signs is nearly impossible. The current literature describes a variety of diagnostic aids, with radiographic imaging considered the gold standard. Therapeutic approaches aim at the evacuation of sand from the abdomen. This can be achieved by the administration of psyllium in connection with a laxative via nasogastric intubation. Several studies describe varying laxatives such as mineral oil or sodium-/magnesium sulphate. This narrative review includes 39 publications up to the year 2026. We aim to raise awareness among practicing veterinarians and highlight new research objectives to improve knowledge and treatment of gastrointestinal diseases related to sand accumulation. Full article

This study evaluated natural halloysite from the Dunino deposit as a sorbent for Pb²⁺, Cd²⁺, Cu²⁺, Zn²⁺, Hg²⁺, and Cr³⁺ ions from aqueous solutions. Batch experiments were conducted to examine the effects of solution pH, initial metal concentration, contact time, and multicomponent conditions. Equilibrium data were evaluated using the Langmuir and Freundlich models, whereas adsorption kinetics were analyzed using pseudo-first-order, pseudo-second-order, and Weber–Morris intraparticle diffusion models. Metal uptake increased markedly between pH 3 and 5, while changes between pH 5 and 7 were smaller. Nonlinear Langmuir fitting yielded maximum adsorption capacities ranging from 47.68 to 63.87 mg g⁻¹, with the highest values obtained for Hg²⁺ and Pb²⁺. The pseudo-first-order model provided a closer empirical description of the kinetic data than the pseudo-second-order model, and the adsorption profiles approached a plateau after approximately 480–720 min. SEM, FTIR, and nitrogen adsorption measurements revealed changes in surface morphology, the chemical environment of surface functional groups, and nitrogen-accessible surface area after metal loading. These observations are consistent with the involvement of surface sites but do not identify a unique molecular adsorption mechanism. Acidic desorption using 0.1 M HCl released 75.0–92.5% of the retained metals, compared with 25.0–47.5% under alkaline conditions. The results support further evaluation of natural halloysite as a mineral sorbent, including matched competition experiments and repeated adsorption–desorption cycles. Full article

Chromium (Cr) contamination poses a serious threat to agricultural productivity and food safety, yet effective strategies for mitigating Cr toxicity under practical cultivation conditions remain limited. In this study, green-synthesized selenium nanoparticles (SeNPs), prepared from banana peel extract (average particle size: 112.9 nm), were evaluated against conventional sodium selenite (Na₂SeO₃) for alleviating Cr(VI) toxicity in Ipomoea aquatica Forssk. grown in a dynamic cyclic hydroponic system. Plants were exposed to 20 mg L⁻¹ Cr(VI) and treated with SeNPs or Na₂SeO₃ at 1 and 10 mg L⁻¹, respectively, for a duration of one week. Green-synthesized SeNPs exhibited excellent colloidal stability (zeta potential: −35.5 mV) and an amorphous spherical morphology. Relative to the Cr-only treatment, 10 mg L⁻¹ SeNPs almost completely restored plant biomass and root growth, decreased shoot Cr accumulation by 62.2%, and recovered total chlorophyll content to 94.8% of the control level. By comparison, 10 mg L⁻¹ Na₂SeO₃ restored total chlorophyll to 74.2% of the control and reduced shoot Cr accumulation by 50.6%. SeNPs also elicited a stronger antioxidant response, markedly increasing SOD, POD, and CAT activities while significantly lowering H₂O₂, MDA, and proline levels, demonstrating a greater capacity than selenite to alleviate Cr-induced oxidative damage. SeNPs also restored the uptake of essential mineral nutrients (N, P, K, Ca, and Mg), improved soluble sugar and protein contents, and promoted selenium biofortification in edible shoots. Although both selenium forms alleviated Cr-induced growth inhibition and oxidative damage, SeNPs consistently outperformed Na₂SeO₃ owing to their higher bioavailability and sustained physiological activity. Overall, this study demonstrates that green-synthesized SeNPs provide an efficient and sustainable strategy for reducing Cr accumulation while simultaneously improving crop growth, antioxidant capacity, and nutritional quality under agriculturally relevant hydroponic conditions, highlighting their potential for safer food production and agricultural waste valorization. Full article

Panicum turgidum is an important keystone forage grass crucial for ecosystem stability in arid and semi-arid rangelands of Asia and Africa. This study aimed to investigate the use of beneficial bioinoculants for enhancing the growth and acclimatization of micropropagated desert grass under controlled environmental conditions. Tissue-cultured plants were transferred to pots with a sand–soil mixture (1:1, v/v) and kept in a temperature and light-controlled environment (25 ± 2 °C, 100 µmol m⁻²·s⁻¹, and 16/8 light/dark photoperiod) for 10 weeks. We used a factorial approach to investigate the effects of the arbuscular mycorrhizal fungus (AMF) Rhizophagus fasciculatus, Trichoderma harzianum, and Bacillus subtilis on transplanted desert grass plants. Two AMF levels control (AMF, 5%; w/w) or without AMF (NAMF); and three microbial inoculation treatments (T. harzianum, B. subtilis, and a combination of T. harzianum + B. subtilis) were employed. Microscopic investigation indicated the extent of AMF colonization in the roots of micropropagated P. turgidum plantlets during acclimatization. Growth parameters with shoots and roots, chlorophyll and carotenoid content, and nitrogen uptake were all improved in bioinoculants-treated plants. Under non-AMF conditions, co-inoculation with T. harzianum and B. subtilis resulted in the highest biomass and root traits, whereas under AMF conditions, T. harzianum alone or with AMF was generally most effective. In the plants treated with the combination of inoculants, heatmap correlation, principal component analysis, and hierarchical clustering demonstrated positive association between growth and physiological traits and the absorption of mineral nutrients, although these associations varied among treatment combinations. These findings highlight the potential of beneficial bioinoculants to improve the growth and acclimatization of micropropagated desert grass plants, providing a foundation for tailored bioinoculant compositions towards the rehabilitation of degraded grazing lands. Full article

Root nitrogen acquisition is a central belowground process that determines how efficiently plants capture nitrogen from the rhizosphere and influences fertilizer demand and environmental nitrogen losses. Root N transporters, including nitrate, ammonium, amino acid, and peptide transporters, provide the molecular basis for inorganic and organic N uptake. However, root N acquisition is not determined solely by plant transport systems but is also shaped by rhizosphere microbial communities that regulate N mobilization, transformation, and availability. In addition to bacteria and archaea, saprotrophic fungi and mycorrhizal associations contribute to organic matter decomposition, N mineralization, and symbiotic N transfer. Mechanistically, transporter activity may alter rhizosphere N gradients and substrate availability, while root exudates and microbial metabolites can influence microbial recruitment, root physiology, and transporter expression. Evidence from rice NRT1.1B and OsLHT1 suggests that specific N transporter genes can influence rhizosphere microbiome assembly, although direct genetic evidence remains limited to a small number of transporter systems and crop contexts. This review synthesizes current knowledge on root N transporter diversity, rhizosphere microbial N cycling, organic N availability, and transporter–microbiome feedbacks in root-level N acquisition. By integrating plant physiology, soil microbiology, and rhizosphere ecology, this review proposes a conceptual framework in which root N transporters and microbial communities act as interconnected components of belowground N acquisition. Future integration of transporter-informed breeding, microbiome management, and fertilization strategies may improve root N capture while reducing reliance on synthetic N inputs. Full article

Background: Osteoporosis is a major public health concern, and early detection through dual-energy X-ray absorptiometry (DXA) has been pivotal. However, evidence on how insurance coverage relates to the distribution of patients receiving DXA examinations in Saudi Arabia remains limited. This study examines the distribution of patients receiving DXA examinations across different insurance types and healthcare settings among adult patients in Saudi Arabia. Methods: This retrospective observational study used de-identified electronic health record data from a public tertiary academic center and a large private healthcare system in Saudi Arabia between 1 January 2023 and 28 February 2026. Dual-energy X-ray absorptiometry (DXA) was employed as an imaging method used to measure bone mineral density and support osteoporosis diagnosis and fracture-risk assessment. Adult patients aged ≥18 years with completed DXA examinations recorded in radiology service records were included. This study assessed the distribution of patients receiving DXA examinations across insurance types, healthcare setting, ordering department, and year of service. Insurance type was categorized as government coverage, private insurance, or self-pay. Descriptive statistics, chi-square tests, one-way ANOVA, Cramér’s V, and standardized residuals were used to compare distribution patterns across groups. Results: The data of 8930 DXA recipients were analyzed. Clear differences were observed in the distribution of patients by insurance type and healthcare setting (p < 0.001). Privately insured patients were predominantly treated in private facilities, whereas government-insured and self-pay patients were primarily concentrated in public healthcare facilities. Significant variations were also observed across healthcare departments and over time, demonstrating strong system-level and financial stratification in the distribution of patients receiving DXA examinations. Conclusions: The findings of this study demonstrate significant differences in the distribution of patients receiving DXA examinations according to insurance type and healthcare setting. Notably, self-pay patients were predominantly managed in public healthcare facilities, whereas privately insured patients primarily received DXA examinations in private healthcare settings. These observed patterns suggest that differences in healthcare organization and insurance financing may be associated with where patients receive DXA examinations; however, because this study included only individuals who underwent DXA examinations, the findings should not be interpreted as measures of screening uptake, access, or equity among all patients eligible for osteoporosis screening. Future healthcare strategies should focus on strengthening equitable insurance coverage, improving coordination between public and private healthcare sectors, standardizing referral pathways, and supporting integrated preventive care in line with Saudi Arabia’s Vision 2030 healthcare transformation. Full article

Selenium (Se) is a beneficial element that enhances plant antioxidant capacity, improves fruit quality, and contributes to the biofortification of horticultural crops. However, information regarding its effects on mineral nutrient balance and antioxidant metabolism in pomegranate remains limited. This study investigated the effects of foliar selenium (Se) application on fruit yield, mineral nutrient balance, antioxidant metabolism, and fruit quality of pomegranate (Punica granatum L.) cv. ‘Malas Saveh’ during the 2022 and 2023 growing seasons under orchard conditions in Iran. Trees were treated with sodium selenate at different concentrations using a randomized complete block design. In 2022, Se was applied at 0, 2, 4, and 6 mg L⁻¹, while in 2023, based on the results of the first-year screening phase, the concentration range was expanded to 0, 6, 8, and 10 mg L⁻¹ to further investigate plant responses to higher Se levels. Foliar Se application significantly increased fruit yield, fruit number, and Se accumulation in both leaves and fruits, confirming the effectiveness of Se biofortification. Selenium treatments also improved the nutritional composition of pomegranate fruits by increasing the concentrations of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), and zinc (Zn), whereas manganese (Mn) concentrations declined, suggesting an antagonistic interaction between Se and Mn uptake. Significant improvements were observed in fruit quality traits, including soluble solids content, titratable acidity, vitamin C, total phenolics, anthocyanins, and antioxidant activity. The 6 mg L⁻¹ treatment in 2022 and the 8–10 mg L⁻¹ treatments in 2023 resulted in the most pronounced physiological and biochemical responses, with 10 mg L⁻¹ showing no further significant improvement for several key traits. Selenium application also enhanced the antioxidant defense system through increased activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL), and ascorbate peroxidase (APX), while reducing hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and membrane ion leakage. Principal component analysis further confirmed the strong positive association between higher Se concentrations and improved mineral and biochemical characteristics. Overall, foliar Se application effectively enhanced pomegranate productivity, nutritional quality, antioxidant capacity, and physiological performance, highlighting its potential as a sustainable agronomic practice for the production of high-quality Se-enriched fruits. Full article