Search Results (2,421)

Bolboschoenus planiculmis is a dominant clonal sedge in saline–alkaline wetlands of the Songnen Plain, and its corms provide important food resources for migratory waterbirds. However, its growth mechanism under saline alkali conditions is still unclear. We combined a field survey with a greenhouse experiment that decoupled saline–alkaline stress into two associated constraints, physiological drought and nitrogen deficiency. Six treatments were established: control, nitrogen deficiency, PEG-induced physiological drought, their combination, moderate saline–alkaline stress, and severe saline–alkaline stress. In the field, soil electrical conductivity and pH increased synchronously, whereas inorganic nitrogen availability was heterogeneous. In the greenhouse, compared with the CK, moderate and severe saline–alkaline stress reduced total biomass by approximately 47% and 51%, respectively, and inhibited leaf growth, root expansion, and corm biomass. It also increased SOD and CAT activities, and ${\mathrm{H}}_2$${\mathrm{O}}_2$ and MDA accumulated. ¹⁵N tracing further showed reduced nitrogen enrichment and lower nitrogen input into corms under saline–alkaline stress, despite partial maintenance of corm allocation. Integrated trait analyses suggested that growth limitation was associated with oxidative damage, restricted morphological development, defense costs, and reduced nitrogen acquisition. These findings provide a plant-level perspective that may inform future assessments of belowground food-resource conditions in migratory waterbird stopover habitats. Full article

The Songnen region in northeastern China contains one of the world’s three largest area of soda saline–alkali soils. Its grasslands are experiencing severe salinization and nutrient impoverishment, which threaten regional ecological security. While nitrogen (N) and phosphorus (P) additions are widely applied to restore degraded grasslands, how the biomass stability of different dominant plant communities responds to such inputs remains unclear. Here, we compared two representative communities—one dominated by Leymus chinensis and the other by Puccinellia distans—under four treatments: control, N addition (15 g N m⁻²), P addition (15 g P₂O₅ m⁻²), and combined N + P addition. N and P additions increased species dominance in both communities, yet diversity and evenness declined in L. chinensis and increased in P. distans. Aboveground biomass peaked under N + P (increasing by 146.82% and 82.16%, respectively). Critically, biomass stability showed opposing trajectories: it rose by 27.69% in L. chinensis under N + P, but fell by 50.90% in P. distans under N alone. Mantel tests and random forest analyses linked biomass stability in L. chinensis to multiple soil enzymes, nutrients, and plant diversity, whereas P. distans biomass stability was primarily regulated by microbial nitrogen and phosphorus. Structural equation modeling further indicated that nutrient inputs in L. chinensis triggered a complex soil microbial–enzymatic cascade that positively coupled plant biomass and soil nutrients with biomass stability, while diversity exerted a negative effect. In P. distans, biomass stability was negatively driven by soil nutrients and biomass, with enzyme activity playing a mediating role. These findings reveal contrasting biomass stability-regulation mechanisms and provide a mechanistic basis for targeted restoration of saline–alkali grasslands. Full article

The ever-increasing output of coal gasification slag from coal gasification technology has created an urgent need for its efficient disposal. In this study, the fine-slag fraction is uti-lized as a precursor to prepare a carbon electrocatalyst for Li-O₂ batteries. Residual carbon was extracted from coal gasification fine slag via an integrated alkali-acid co-activation process. Subsequently, hydrothermal modification reconstructed the carbon microstructure and strengthened its coupling with intrinsic Ca-containing species. The as-prepared slag-derived catalyst improved oxygen-reaction kinetics at the battery cathode and effectively reduced polarization. The Li-O₂ cells delivered a low charge–discharge voltage gap of 1.02 V, a high discharge specific capacity of 9480 mAh g⁻¹, and stable long-term cycling for more than 870 h. The enhanced electrochemical performance arises from the synergistic interplay among the reconstructed carbon framework, surface defects, oxygen-containing functional groups, and Ca-containing species, with the latter serving as a major source of active sites for the oxygen electrocatalytic reactions. This work establishes a resource-utilization pathway from coal gasification slag to high-end energy-storage applications, aligning with green development goals to address both mining-area energy demands and solid-waste pollution. Full article

3D-printed geopolymer mortars (3DPGPMs) are emerging as low-carbon construction materials that combine digital fabrication with alkali-activated binder technology. However, their hardened performance remains difficult to assess because it is controlled not only by geopolymer chemistry but also by printing parameters, rheological evolution, curing conditions, interlayer bonding, pore structure, and loading direction. This review critically examines the current literature on extrusion-based 3DPGPMs, with emphasis on mechanical properties, durability, sustainability, standardization, and practical implementation. The reviewed studies show that precursor type, activator system, aggregate/binder ratio, additives, printing conditions, and curing regime strongly influence compressive, tensile, flexural, interlayer bond, and anisotropic mechanical responses. Durability performance is also governed by the coupled effects of matrix chemistry and printing-induced features, including interlayer voids, directional pore networks, weak interfaces, and transport pathways that may affect shrinkage, water absorption, chloride penetration, carbonation, acid and sulphate resistance, freeze–thaw response, and elevated-temperature behavior. From a sustainability perspective, the environmental benefits of 3DPGPMs are conditional and depend on activator production, precursor availability, curing demand, transport distance, life-cycle assessment boundaries, and field-scale implementation conditions. The review identifies that the main knowledge gap is the limited availability of integrated datasets linking fresh-state rheology, interlayer quality, multi-scale porosity, mechanical anisotropy, durability indicators, and structural-scale validation. Future research should therefore prioritize standardized reporting, performance-based acceptance criteria, long-term exposure testing, field-scale validation, and predictive material–process–durability models. Overall, this review provides a hardened-performance-oriented synthesis to support the development of reliable, durable, and sustainable 3DPGPMs for construction applications. Full article

Soil salinization has become a major global abiotic threat restricting sustainable viticulture, especially in coastal and inland saline–alkali zones. Unlike cereal crops mainly suffering from sodium toxicity, grapevine (Vitis vinifera L.) is a typical chloride-sensitive woody perennial, subjected to superimposed damages of osmotic stress, ionic imbalance and secondary oxidative injury under saline conditions which severely suppress vegetative growth and degrade berry quality. This review systematically summarizes the multi-layered physiological adaptive mechanisms of grapevine against salt stress, including ion homeostasis maintained by salt overly sensitive (SOS), Na⁺/H⁺ exchanger (NHX) and chloride channel (CLC) transporter families, active accumulation of osmoprotectants, synergistic enzymatic and non-enzymatic antioxidant systems, and phytohormone crosstalk networks formed by endogenous phytohormones (abscisic acid, ABA; jasmonic acid, JA; salicylic acid, SA; brassinosteroid, BR) and small signaling molecules. We further elaborate comprehensive molecular regulatory cascades governing salt tolerance, covering core functional genes for ion transport, master transcription factor families WRKY, MYB, APETALA2/Ethylene Response Factor (AP2/ERF), NAC, basic helix–loop–helix (bHLH) and emerging epigenetic regulatory layers mediated by deoxyribonucleic acid (DNA) methylation, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). In addition, we integrate four categories of field mitigation strategies for saline vineyards: germplasm improvement via salt-tolerant rootstock grafting, rhizosphere soil basal amendment, exogenous biostimulant regulation, and precision agronomic optimization. Current experimental systems do not fully recapitulate complex field combined-stress conditions, as most studies rely on laboratory single-salt stress simulation. Meanwhile, multi-omics, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) gene editing and high-throughput phenotyping tools provide promising approaches to deepen our understanding of grape salt tolerance. This review constructs a comprehensive theoretical framework linking physiological responses, molecular regulatory networks and practical field technologies, offering systematic theoretical references and technical guidance for salt-tolerant germplasm innovation and environmentally sustainable viticulture on saline soils. Full article

To address the high carbon emissions generated during the production of cement, lime, and other traditional soil stabilizers and to promote the resource utilization of industrial solid waste, this study proposed a low-carbon loess stabilization scheme using tuff powder (TP), fly ash (FA), and ground granulated blast-furnace slag (GGBS) activated by alkaline solutions to fully substitute conventional cement and lime. A series of macroscopic tests, including unconfined compressive strength, water immersion, and triaxial shear tests, were carried out on stabilized loess. Combined with microcharacterization including X-ray diffraction (XRD), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) spectroscopic testing, this study systematically evaluated the mechanical performance, water stability, and microstructural evolution of stabilized loess and quantified its global warming potential (GWP). Macroscopic test results reveal that the composite binder consisting of 15% multi-source solid waste (TP:FA:GGBS) = (1:1:3), 3% NaOH, and 3.2% Na₂SiO₃ (relative to solid waste mass) delivers the optimal comprehensive performance of stabilized loess. Alkali activation significantly accelerates early strength development, and both compressive and shear strengths are markedly improved compared with samples treated solely with solid waste. Furthermore, decreasing the activator modulus further enhances mechanical properties and water resistance. Microscopic characterizations demonstrate that alkali activation stimulates the pozzolanic reaction of active components in solid waste, generating cementitious gels that bind soil particles and unreacted solid waste to form dense network matrices. As a fine filler, TP also acts as a nucleation sites for hydration product crystallization, which facilitates the formation of cementitious phases. Full article

This study evaluates the mechanical performance, anisotropy, and spatial variability of 3D-printed cementitious and alkali-activated composites under laboratory, atmospheric, and freeze–thaw conditions. Alkali-activated composites exhibited substantially higher shrinkage than cement-based mixtures, reflecting differences in their reaction mechanisms and pore structure development. Compressive strength was measured in two orthogonal directions representing perpendicular ($⟂$) and parallel ($\parallel$) behaviour. Non-activated mixtures exhibited compressive strength of 11–12 MPa, whereas alkali-activated composites reached 19–20 MPa in the reference condition. Atmospheric exposure increased compressive strength by 10–22%, while freeze–thaw cycles did not significantly affect perpendicular strength. Flexural strength of non-activated mixtures remained low (3.7–5.3 MPa), whereas activated composites showed higher values in the reference state (8.8–15.0 MPa) but decreased after atmospheric exposure to 5.3–5.8 MPa. The degree of anisotropy increased significantly for alkali-activated mixtures (from 0.09 to 0.24) while remaining relatively stable for non-activated materials (0.04–0.11). Glass fibres showed no significant degradation after environmental and freeze–thaw exposure, while merino wool fibres exhibited only minor surface irregularities, confirming the potential of both fibre types for use in sustainable lightweight 3D-printed cementitious and alkali-activated composites. Full article

An innovative cement and alkali-activated gradient cementitious composite was fabricated via mixed and layered casting methods. The influence of casting method and mix proportion on mechanical performance was systematically investigated, and the compatibility and synergistic mechanisms were characterized by XRD, FT–IR, and SEM. Mixed casting resulted in severe incompatibility, with the compressive strength plummeting to 18.7 MPa, a 66.5% reduction compared to the single-component binders. In contrast, layered casting enabled compatibility and coupling between the gradient layers, imparting a pronounced synergistic strengthening effect. The optimal alkali-activated material-to-cement ratio was 8:2, achieving a compressive strength of 62.7 MPa, which is 12.4% higher than that of the single-component composite. Microstructural analysis revealed that, under layered casting, the alkali-activated component continuously consumed the cement hydration by-product Ca(OH)₂ to form calcium aluminosilicate hydrate (C-A-S-H) gel, generating a synergistic reinforcement in the interfacial region and enhancing the overall performance of the composite. Full article

Saline–alkali stress severely restricts cucumber (Cucumis sativus L.) growth by disrupting ion balance, water status, photosynthesis, and redox homeostasis. Here, we examined the effects of exogenous selenium (Se) on cucumber seedlings exposed to NaHCO₃ stress. Se supplementation improved plant growth and root activity and partly restored photosynthetic performance by maintaining chlorophyll content, gas exchange, and chlorophyll fluorescence. Se reduced oxidative injury through lower ROS and MDA levels and by enhancing antioxidant enzyme activities together with the AsA–GSH cycle. In parallel, Se moderated ion toxicity by limiting Na⁺ accumulation, increasing K⁺, Ca²⁺, and Mg²⁺ uptake, and stimulating H⁺-ATPase and H⁺-PPase activities. Enhanced TCA cycle activity and organic acid accumulation suggested improved energy metabolism and ionic regulation. Se also promoted osmotic adjustment via soluble sugars and proline, and upregulated aquaporin genes (PIP1;2 and PIP2;4) to sustain water transport. Moreover, Se increased salicylic acid levels by upregulating CsPAL and CsICS, pointing to a role of SA signaling in Se-induced tolerance. Full article

In silico structural characterization of carbohydrate-active enzymes (CAZymes) in Bacillus subtilis T7 reveals mechanistic insight into the strain’s capacity for consolidated bioprocessing of untreated lignocellulosic biomass. Homology models for 13 CAZymes were constructed using SWISS-MODEL, with Cu²⁺ and FAD cofactors incorporated into the AA10 lytic polysaccharide monooxygenase and AA3 oxidoreductase models, respectively. Blind molecular docking across the full protein surface identified energetically favorable binding pockets on GH9 endoglucanase and Abhydrolase_1. Among 12 enzyme–ligand pairs screened, Abhydrolase_1 exhibited the highest affinity for xylotetraose (−7.7 kcal/mol) and GH9 showed the strongest preference for cellotetraose (−7.0 kcal/mol). Site-specific docking confirmed six hydrogen bonds with Gly32, Phe33, Thr34, Ser36, Arg179, and His256, supplemented by two carbon–hydrogen bonds with Ile180 and Ser39, anchoring xylotetraose within the Abhydrolase_1 binding cavity, and seven hydrogen bonds stabilizing cellotetraose in the GH9 catalytic groove, with key contacts at Tyr141, Trp145, Asp194, Trp193, Arg254, Tyr255, and Tyr354. One-hundred nanosecond all-atom molecular dynamics simulations (GROMACS 2023.2, CHARMM36 force field, triplicate runs) confirmed overall structural integrity for both proteins: Abhydrolase_1 maintained a compact conformation (Rg = 18.11 ± 0.09 Å; backbone RMSD 2–3 Å), while GH9 was similarly stable (Rg = 30.36 ± 0.33 Å; RMSD 2–5 Å). Ligand dynamics were more variable—xylotetraose remained bound within the Abhydrolase_1 active site for approximately 75 ns before partial displacement, whereas cellotetraose exhibited dynamic association along the GH9 catalytic channel, consistent with processive substrate translocation in endoglucanases. These computational findings line up with the strain’s experimentally observed hydrolytic clearance zones (cellulase 24.5 mm; xylanase 11.6 mm), 63.4% alkali lignin decolorization, transient accumulation of ferulic acid and vanillin, and a hydrogen yield of 1.41 mol H₂/mol substrate from untreated food waste. Together they give a molecular-level picture of substrate-specific CAZyme recognition in B. subtilis T7 and support its potential as a pretreatment-free platform for lignocellulosic biohydrogen production. Full article

This study presents a laboratory-scale assessment of heat-assisted fly ash-based geopolymer concrete as a potential thin protective layer in one asphalt–geopolymer pavement configuration. The programme comprised water penetration under pressure, abrasion, initial skid resistance, wheel tracking, four-point-bending fatigue, mechanical strength, freeze–thaw response, de-icing-salt scaling, thermal characterization, and qualitative scanning electron microscopy. The selected geopolymer reached mean flexural, compressive, and splitting tensile strengths of 10.756, 61.058, and 3.797 MPa, respectively. Final rut depths were 1.57 mm after 7 days and 0.72 mm after 28 days, with corresponding WTSAIR values of 0.020296 and 0.014238 mm per 10³ cycles. After 10⁶ cycles at 10 Hz, 72–85% of the initial stiffness modulus remained across the tested strain levels. Mean de-icing-salt scaling was 0.500 kg/m² after 28 days and 0.995 kg/m² after 56 days. Standalone geopolymer specimens underwent full-depth water penetration, whereas no leakage through the asphalt layer was observed in the intact layered specimen during the 5 bar, 72 h test. This system-level observation supports functional tightness only under the tested intact condition and does not establish intrinsic material impermeability or long-term interface durability. Interpretation is limited to this laboratory-scale configuration: the 90 °C heat-assisted curing protocol limits transfer to conventional in situ paving; no ambient- or standard-cured control and no same-condition conventional overlay control were included; and only one composite geometry was evaluated. The findings therefore define application boundaries for further validation rather than a field-ready specification or proof of comparative superiority. Full article

To address the rapid flash setting of NaOH-activated slag and promote high-volume utilization of coal-based solid wastes, this study investigated the synergy of fly ash (FA), coal gangue (CG), and gasification slag (GS) in partially replacing granulated blast furnace slag (GBFS) for NaOH activated binders, aiming to mitigate flash setting while preserving mechanical performance. Binary and ternary pastes with up to 90 wt% substitution were evaluated for setting time, fluidity, and compressive strength, supported by quantitative XRD and SEM. The G8F1G1 achieved the optimal balance, extending initial and final setting times from 28 and 32 min to 35 and 43 min, yielding a fluidity of 218 mm, and maintaining a 28-day strength of 48.5 MPa, equivalent to neat GBFS. The FA-GS synergy suppressed crystalline by damping the Ca²⁺ supersaturation peak through FA derived oligomers while providing nucleation sites via fine carbonaceous particles in GS, thereby retaining the amorphous C-A-S-H gel at approximately 77 wt%. This preserved the load-bearing gel network but eliminated early percolating crystalline frameworks, extending workability without strength loss. In contrast, CG acted as an inert diluent, introducing weak interfaces and porosity that severely degraded strength. A critical amorphous threshold near 64 wt% (G6F2G2, amorphous gel) governed the transition to a granular bed. The FA-GS system offers an effective route for high-volume valorization of coal-based solid wastes in sustainable construction materials. Full article

Chloride-induced corrosion is a major threat to excavated bronze artifacts, yet conventional alkaline desalination requires repeated solution replacement and generates secondary chemical waste. Herein, a series of BiOCl-loaded carbon nanofiber composites (CNFs@BiOCl-X) were prepared by KOH activation followed by hydrothermal growth of BiOCl, aiming to develop regenerable electrodes for chloride removal in capacitive deionization systems. Alkali activation regulated the surface roughness, oxygen-containing functional groups, hydrophilicity, and BiOCl loading of CNFs, while the three-dimensional conductive network helped immobilize BiOCl nanostructures and buffer the volume variation associated with reversible Bi/BiOCl conversion. Electrochemical analyses confirmed the pseudocapacitive chloride-storage behavior of the composites, with ion removal governed by the coupled effects of BiOCl redox activity, charge transfer, and interfacial ion transport. In a fixed-electrode membrane capacitive deionization system, CNFs@BiOCl-2 exhibited the best overall performance, delivering a salt adsorption capacity of 100.44 mg g⁻¹ at 1.4 V and retaining 93.17% of its desalination capacity after 35 cycles at 1.2 V. For flow-electrode capacitive deionization, the higher BiOCl-loading CNFs@BiOCl-5 showed superior utilization of active sites and achieved 94.75% NaCl removal from a 1000 mg L⁻¹ solution within 3 h, with an average desalination rate of 15.48 μg cm⁻² min⁻¹ and an energy consumption of 0.88 kWh kg⁻¹-NaCl. These findings demonstrate that rationally matching BiOCl loading with electrode configuration enables efficient and sustainable chloride management, offering a promising electrochemical strategy for conservation electrolytes and related desalination applications. Full article

Background: Visual impairment frequently impairs balance and motor coordination, yet the underlying neural circuit mechanisms remain poorly understood and require further investigation. In this study, we established a mouse model of visual impairment to assess the effects of defective vision on balance and coordination and further elucidated the functional role of the V1-M2 neural circuit in this process. Methods: A mouse model of corneal alkali burn was generated. Corneal morphology was observed, visual function was detected, and balance as well as motor coordination were evaluated. Neuronal activation in the V1 and M2 brain regions was quantified via c-Fos immunostaining. Viral tracing was performed to map the V1-M2 neural pathway, and chemogenetic manipulation was applied to modulate the V1-M2 circuit. Results: Mice subjected to corneal alkali burn exhibited abnormal corneal morphology and impaired visual function, accompanied by significant deficits in balance and motor coordination. The number of c-Fos⁺ neurons was markedly reduced in both the V1 and M2 regions. The direct V1-M2 neural circuit was anatomically verified. Chemogenetic activation of the V1-M2 circuit elevated c-Fos expression in M2 and rescued impaired motor performance. Conclusions: Visual impairment disrupts balance and motor coordination in mice. The V1 and M2 cortical areas mediate this behavioral dysfunction, likely due to attenuated activation of the V1-M2 neural circuit. These findings identify a promising neural circuit for dissecting the fundamental mechanisms underlying visuomotor integration. Full article

To understand the adaptive evolution of endangered plateau freshwater fishes to environmental stress and to better explore the underlying mechanisms in Aspiorhynchus laticeps—a critically endangered fish endemic to the Tarim Basin, Xinjiang, China—a combination of ecological experiments and transcriptome sequencing (RNA-seq) technology was used to study the differences in gene expression patterns among individuals under different salinities and flow conditions. This experiment included four treatment groups (CON, H-SA-S, L-SA, L-SA-S). A. laticeps specimens with an average weight of 2.92 ± 0.62 g and a body length of 58.22 ± 5.10 mm were selected, with three biological replicates for a 96 h combined stress treatment. Moreover, the relationships between these differences and the aquatic environment were analyzed. A total of 1847 differentially expressed genes (DEGs), including 935 upregulated genes and 912 downregulated genes, were identified under different aquatic environment stress modes. GO and KEGG enrichment analyses revealed that TNF signal transduction, the NF-κB pathway, and metabolic regulation were significantly enriched among the DEGs (p < 0.05). High salinity–alkali stress significantly activates the TNF/NF-κB pathway, regulates MST1, LOC107702867, LOC113110979 and other genes to enhance the body’s resistance; water flow changes mainly regulate energy metabolism through genes such as NEHOM01_1600 and gptl. These findings provide an important scientific basis for the ecological adaptability, protection, and proliferation of endemic and endangered fish in China, as well as for germplasm innovation to address ecological deterioration in plateau fishes in alpine and arid areas. This study provides a molecular-level theoretical foundation for artificial habitat regulation and the conservation of endangered Aspiorhynchus laticeps populations in the Tarim River. Full article