Search Results (2,307)

It is essential to design electrode structures which simultaneously ensure mechanical strength and facilitate rapid sodium-ion transport to enable practical and large-scale sodium-ion battery (SIB) applications. In this study, we report a novel anode material featuring a cross-linked architecture composed of MoS₂ reinforced internally by catalytically derived CoS₂@C-supported carbon nanotubes (CNTs), and externally by commercial multi-walled carbon nanotubes (MWCNTs). This dual-reinforced configuration effectively prevents MoS₂ layer aggregation, enhances structural integrity, and establishes continuous conductive frameworks for efficient electron transmission. Additionally, it offers ample ion-diffusion pathways and mechanical resilience to buffer volume changes during cycling. Density functional theory (DFT) simulations reveal that the modified MoS₂ structure exhibits a significantly reduced sodium-ion diffusion barrier, contributing to enhanced charge-discharge kinetics. The CoS₂@C/CNTs@MoS₂@MWCNTs electrode achieves remarkable cycling stability, retaining 395 mA h g⁻¹ at 1 A g⁻¹ for 2000 cycles. In situ X-ray diffraction (XRD) along with kinetic analyses confirm a pseudocapacitance-dominated storage mechanism. Furthermore, full coin-type cells assembled with Na₃V₂(PO₄)₃ cathodes demonstrate excellent cycling performance, demonstrating the practical potential of this design strategy for advanced SIBs. Full article

Middle-phase (Winsor III) microemulsion flooding is a promising technique for enhanced oil recovery (EOR). However, the presence of natural polar components in crude oil and varying reservoir salinity complicate the formulation of optimal microemulsion systems. This study experimentally investigates the effects of salinity and organic acids (lauric acid and caprylic acid) on the phase behavior of a microemulsion system composed of sodium dodecyl sulfonate (SDS), n-butanol, and different oils. Phase behavior experiments revealed that the optimal salinity window for middle-phase formation increases with the carbon number of the oil phase, expanding from 3–6.6 to 4–8.5 and 6–11.8 g/100 mL for octane, decane, and dodecane, respectively. The addition of polar acids was found to narrow this optimal salinity range; in particular, for decane, an increase in lauric acid concentration from 0.1% to 0.9% narrowed the salinity window from 4–8 to 4–6 g/100 mL, making the microemulsion systems more sensitive to salinity changes. Subsequent core flooding experiments demonstrated that the presence of polar components enhances the ultimate oil recovery, with higher acid concentrations leading to faster production rates. Furthermore, the EOR performance was shown to be highly dependent on salinity, peaking within the optimal salinity range that promotes a stable Winsor III microemulsion, leading to an ultimate recovery as high as 68.8%. These findings provide crucial insights for designing robust surfactant formulations for EOR in reservoirs containing polar crude oils. Full article

Organic amendments derived from agro-livestock residues offer a promising approach for soil restoration and nutrient recycling within circular economy frameworks. Nevertheless, their agronomic efficacy and environmental suitability may be contingent upon the formulation of the amendments and the properties of the soil. This study presents a preliminary evaluation of customized organic amendments derived from solid materials, such as biochar and green compost, and liquid residues, including cattle manure slurry, urban compost tea, and cattle digestate. These were applied either individually or as solid–liquid mixtures to two distinct Iberian soils. The study involved amendment characterization, seed germination assays, and a two-month greenhouse experiment with barley (Hordeum vulgare L.) to assess the effects on soil physicochemical properties, microbial activity, and plant development. The solid–liquid impregnation process facilitated the transfer of nutrients and potentially limiting elements from liquid residues to solid matrices, thereby altering amendment composition and mitigating some risks associated with the direct application of liquid residues. Mixtures based on biochar and compost generally alleviated excessive salinity and trace metal constraints, although responses varied depending on the liquid amendment and soil type. Biochar-containing amendments markedly increased soil total carbon, suggesting their potential to contribute to soil carbon sequestration. The effects of amendments were strongly dependent on soil type: acidic soil exhibited more pronounced pH improvement, whereas the carbonate-rich alkaline soil buffered several chemical changes but was more susceptible to alkalinization and sodium inputs. Urban compost tea consistently exhibited inhibitory effects on germination, plant development, and dehydrogenase activity, although these effects were partially mitigated when combined with solid amendments. Overall, the findings underscore the potential of tailored amendment mixtures to enhance residue valorisation, while highlighting the necessity for soil-specific evaluation prior to field application. Full article

Protein solubility can limit enzyme performance in industrial applications. This is the case for some carbonic anhydrases (CAs), key enzymes for CO₂ capture and utilization. In this study, we investigated an α-class CA from the thermophilic bacterium Hydrogenimonas thermophila (HtCA), which was predominantly expressed as an insoluble protein in Escherichia coli. Surface analysis using Molecular Operating Environment (MOE) revealed extensive hydrophobic regions, suggesting a basis for its poor solubility. To improve solubility, three C-terminal fusion tags were evaluated (Gb1, ng3-NEXT, and T7B9). All tagged variants showed markedly increased soluble expression as determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis. To reduce surface hydrophobicity, selected residues were substituted with charged amino acids. Most variants displayed improved solubility, and V136D showed enhanced thermostability, retaining 76% activity after exposure to 90 °C for an hour. However, the F177D variant completely lost all enzymatic activity, highlighting the importance of evaluating both solubility and catalytic function during protein engineering. Molecular dynamics simulations supported the experimental findings, revealing that thermostable variants exhibited reduced structural fluctuations and favorable free-energy landscapes, while the inactive F177D mutant sampled a broader conformational space and higher-energy conformations, consistent with decreased structural stability and loss of catalytic activity. Full article

This study evaluated the synergistic effects of sodium chloride (NaCl) and cytidine monophosphate (CMP) on enhancing the co-production of astaxanthin and fatty acids while suppressing secondary cell wall (SCW) formation in Haematococcus lacustris (synonym: H. pluvialis) under high-light stress. An orthogonal design identified the optimal combination (0.5 g/L NaCl and 0.5 mM CMP), which significantly increased astaxanthin yield by over 35.6% and total fatty acid yield by 28%, while maintaining 96.8% of cells in motile state (SCW-deficient). Physiological analyses revealed elevated reactive oxygen species levels, concomitant with higher actual photochemical efficiency (Fv′/Fm′) and relative electron transport rates II (rETR(II)) along with enhanced non-photochemical quenching (NPQ) capacity, and metabolic reprogramming characterized by the accumulation of lipids, sugars, and starch alongside decreased protein yield. Metabolomics indicated reduced carbon supply for SCW polysaccharide biosynthesis, coupled with decreased protein yield and altered amino acid profiles characteristic of nitrogen-limited metabolism, which collectively favored the reallocation of carbon resources toward nitrogen-free high-value products. Transcriptomics confirmed the downregulation of SCW component biosynthetic genes and the upregulation of the methylerythritol phosphate (MEP) pathway and astaxanthin biosynthetic pathway. Scale-up experiments validated this strategy for producing astaxanthin-rich motile cells, offering a promising approach for microalgal biorefinery. Full article

Molecularly imprinted polymers combined with carbon nanomaterials have proven effective in constructing electrochemical sensors with high selectivity, sensitivity, and robustness. Herein, a polypyrrole-based molecularly imprinted electrochemical sensor was developed on a multi-walled carbon nanotube-modified glassy carbon electrode for homocysteine detection in human serum. The sensor was fabricated via drop-coating of sodium dodecyl sulfate-dispersed multi-walled carbon nanotubes, followed by in situ electropolymerization of pyrrole using homocysteine as the template. The morphology, interfacial properties, and electrochemical behavior of the electrode were systematically characterized by scanning electron microscopy and electrochemical techniques. Under optimized conditions, the sensor showed a linear response to homocysteine in the range of 1.0 × 10⁻¹⁰ mol/L to 1.0 × 10⁻⁵ mol/L, with a detection limit of 7.12 × 10⁻¹¹ mol/L (S/N = 3). The sensor also exhibited good selectivity against common interferents, as well as acceptable reproducibility and stability. Recovery tests in human serum yielded recoveries of 91.00~110.50% (average: 100.73%), demonstrating its potential for practical homocysteine analysis in complex biological matrices. Full article

Biomass-derived hard carbon (HC) represents a promising anode candidate for sodium-ion batteries, owing to its disordered structure and abundant micropores. This study systematically investigates three chemical oxidation strategies (NaClO, H ₂ SO ₄ and H ₂ O ₂ +NaOH) applied to cotton stalk-derived HC carbonized at 1300 °C. The NaClO-treated sample delivers the optimal overall electrochemical performance, achieving a high discharge capacity of 330.2 mAh g ⁻¹ at 0.1 C, a high initial Coulombic efficiency (ICE) of 81.7%, and a capacity retention of 81.9% after 1000 cycles at 2 C (from 226.0 to 185.1 mAh g ⁻¹ ). This superiority is attributed to the formation of a three-dimensional hierarchical pore network and optimal oxygen functional groups. The H ₂ SO ₄ treatment yields a discharge capacity of 323.2 h g ⁻¹ , an ICE of 75.3%, and a capacity retention of 77.1% after 1000 cycles (from 183.5 to 141.5 mAh g ⁻¹ ), benefiting from structural densification. The H ₂ O ₂ +NaOH treatment delivers a capacity of 269.8 mAh g ⁻¹ and an ICE of 74.2%, exhibiting a distinct activation behavior likely due to its thin pore walls and abundant open mesopores. Overall, all treated samples significantly outperformed the pristine HC, which exhibits a discharge capacity of 320.3 mAh g ⁻¹ , an ICE of 68.0%, and a retained capacity of 90.4 mAh g ⁻¹ after 1000 cycles at 2 C. Full article

MXenes have attracted considerable attention as anode materials for sodium-ion batteries (SIBs) because of their metallic conductivity, hydrophilic surfaces, tunable surface terminations, and layered structures. However, pristine MXenes are limited by nanosheet restacking, oxidation instability, heterogeneous surface chemistry, low initial Coulombic efficiency, and insufficient electrode-level ion accessibility. These issues indicate that MXenes should be regarded not simply as standalone active materials but as multifunctional building blocks for composite electrode design. This review discusses recent progress in MXene-based composite anodes for SIBs, focusing on MXene/carbon composites, MXene/metal compound composites, polymer-assisted composites, and three-dimensional structured MXene composites for improving structural stability, interfacial chemistry, and sodium-storage kinetics. We emphasize that composite engineering can reshape sodium storage from diffusion-limited intercalation toward hybrid mechanisms involving interfacial adsorption, pseudocapacitive storage, heterointerface-driven redox reactions, ion desolvation regulation, and solid-electrolyte interphase stabilization. Key practical challenges, including oxidation control, initial Coulombic efficiency, high-mass-loading electrode design, gravimetric–volumetric performance trade-offs, scalable synthesis, and full-cell validation, are also discussed. Finally, we propose future design principles based on integrated materials chemistry, interfacial science, multiscale architecture engineering, and realistic cell-level evaluation for advancing MXene composites toward practical SIB anodes. Full article

A significant pile-up of phosphogypsum, with utilization under 30% in some areas, has caused serious environmental problems. This study presents a powdered recycled binder-aggregate (PRBA), prepared by activating a phosphogypsum-fly ash-steel slag ternary system via a sodium silicate-calcium hydroxide activator. The optimal L3 at 55% PRBA with PG:FA:SS of 4:3:4 achieved 28-day compressive strength of 9.33 MPa, 22.0% higher than control L0 at 7.65 MPa, reaching 12.47 MPa at 56 days. The C-S-H gel network evolved from 100–200 nm tubular to under 10 nm lamellar structures, reducing average pore diameter from 82 nm to 52.5 nm. Non-isothermal kinetic modeling revealed that C-S-H/AFt dehydration follows Jander three-dimensional diffusion with R² = 0.998 and activation energy decreasing from 161.3 to 99.3 kJ/mol at 14 days. A relay-race mechanism was identified: steel slag provides early Ca²⁺, phosphogypsum supplies SO₄²⁻ forming AFt skeletons, and fly ash densifies the matrix via pozzolanic reactions. Environmental assessment showed P and F solidification rates of 66.7% and 88.3%, plus 10.77 g CO₂/kg carbonation. Converting inert industrial wastes into a reactive cementitious system enables 55% natural aggregate replacement and pollutant immobilization, offering scalable pathways for phosphogypsum valorization in road base applications. Full article

Drought stress severely restricts early growth in Brassica napus, while selenium (Se) can enhance stress tolerance. This study examined how foliar sodium selenite pretreatment affects polyethylene glycol (PEG)-induced drought stress in B. napus seedlings. Seedlings were sprayed with 10, 20, or 40 mg L⁻¹ Na₂SeO₃ for 7 days and then exposed to 10% (w/v) PEG 6000 for 2 days. Drought reduced fresh weight and increased malondialdehyde (MDA), O₂·⁻ production, H₂O₂ accumulation, and antioxidant enzyme activities. The response was nonlinear, and 20 mg L⁻¹ Na₂SeO₃ was most effective. Relative to drought alone, this treatment increased fresh weight from 2.6 to 5.1 g plant⁻¹ and reduced MDA, O₂·⁻, and H₂O₂ by 50.5%, 50.9%, and 44.3%, respectively. Notably, catalase (CAT) and superoxide dismutase (SOD) activities declined markedly from the drought-induced levels, indicating lower oxidative pressure rather than enhanced enzymatic scavenging. Integrated transcriptomic and metabolomic analyses showed associations between selenium pretreatment and pathways related to photosynthesis, carbon fixation, porphyrin metabolism, phenylpropanoid biosynthesis, and selenocompound metabolism. Together, these findings suggest that foliar application of 20 mg L⁻¹ Na₂SeO₃ improves drought tolerance in B. napus seedlings by alleviating oxidative pressure rather than simply increasing antioxidant enzyme activity. Full article

Soil salinization severely threatens agricultural productivity and ecosystem sustainability, particularly in coastal regions. Halophyte-based phytoremediation is a promising strategy, yet how rhizosphere soil legacy effects at different restoration ages influence subsequent plant growth and microbial communities remains poorly understood. Here, rhizosphere soils of Nitraria tangutorum at 1- (BC-1), 2- (BC-2), and 3-year (BC-3) restoration stages and non-rhizosphere bulk soil (CK) were sampled, with alfalfa cultivated as a bioindicator to assess soil physicochemical properties, plant growth, stress physiology, and rhizosphere microbiota. With increasing restoration age, rhizosphere soil shifted from a state of salt accumulation and nutrient deficiency to one of salt depletion and nutrient enrichment, with BC-3 exhibiting the highest soil organic matter, total phosphorus, and alkali-hydrolyzable nitrogen and the lowest total salt and soluble Na⁺. Alfalfa growth was suppressed in BC-1 and BC-2 soils, but significantly promoted in BC-3, accompanied by the lowest malondialdehyde and proline content, indicating effective alleviation of oxidative and osmotic stress. Microbial diversity peaked at BC-2, whereas the total proportion of halotolerant bacteria declined from 0.44 (BC-1) to 0.34 in BC-3 (significantly lower than CK), suggesting a successional shift from a stress-dominated community toward a functionally specialized consortium. Regression analyses identified soluble sodium as the variable most strongly associated with growth inhibition (R² > 0.80) for plant height and root length. We suggest soluble sodium may represent the principal factor associated with growth inhibition and that a positive-feedback loop among plant Na⁺ sequestration, microbial carbon sequestration, and soil maturation may sustain long-term saline–alkali soil improvement. These findings suggest a three-stage successional mechanism and highlight the critical role of restoration age in mediating plant–microbe–soil synergistic remediation of coastal saline soils. Full article

Solute Carrier Family 13 Member 5 (SLC13A5) encodes the sodium-dependent citrate cotransporter NaCT, which mediates citrate transport across cell membranes. Pathogenic variants in SLC13A5 cause developmental and epileptic encephalopathy 25 with amelogenesis imperfecta, DEE25; OMIM #615905, a debilitating autosomal recessive disorder. To better define the role of NaCT in ameloblast function and enamel mineralization, we used CRISPR/Cas9 genome editing to generate Slc13a5^R337* knock-in mice that terminate NaCT translation at the Arg337 codon, which is homologous to the human SLC13A5^R333* variant associated with DEE25. We compared enamel phenotypes among wild-type, Slc13a5^+/+; heterozygous, Slc13a5^+/R337*; and homozygous, Slc13a5^R337*/R337* mice using light microscopy, in situ hybridization, immunohistochemistry, backscattered scanning electron microscopy (bSEM); and focused ion beam–scanning electron microscopy (FIB-SEM) with quantitative imaging of organelles and matrix. Citrate bioassays were performed on serum, long bones, such as the femur and tibia, and developing mouse first molars, including enamel organ epithelium, mineralized tooth matrix, and pulp mesenchyme, to assess citrate levels during the presecretory, secretory, and maturation stages of enamel formation. In addition, first molars collected at postnatal days 0, 3, 5, and 12 were analyzed to characterize glycolytic and TCA cycle-related metabolic signatures. Homozygous Slc13a5^R337*/R337* mice exhibited severe defects during the secretory and maturation stages of amelogenesis. Most notably, Slc13a5^R337*/R337* ameloblasts failed to develop a Tomes’ process, detached from the enamel matrix surface, and produced a thin, poorly mineralized crust on the dentin surface rather than organized enamel ribbons. Despite the absence of normal enamel deposition, ameloblasts initially appeared viable and did not become dysplastic until the late secretory stage. Cellular and subcellular analyses revealed increased secondary lysosomes and intracellular accumulation of enamel matrix proteins, consistent with impaired matrix processing or secretion. Citrate concentrations were elevated in serum and long bones at both 7 and 35 weeks of age. Citrate was elevated in secretory-stage Slc13a5^R337*/R337* molars at days 0 and 3, the enamel organ epithelium (including ameloblasts), the pulp mesenchyme (including odontoblasts), and mineralizing dentin and enamel matrices. These levels gradually declined at day 5 and into the enamel maturation stage (day 12). GC-MS-based analysis of central carbon metabolites revealed increased intracellular accumulation of citrate, malate, and pyruvate, suggesting altered energy metabolism and reduced metabolic efficiency in Slc13a5^R337*/R337* mice. Together, these findings indicate that loss of NaCT function in the ameloblasts causes citrate accumulation, which impairs hydroxyapatite formation. Consequently, only a thin, structurally defective mineral crust forms on the dentin surface, while mineral nodules develop ectopically within the maturation-stage enamel organ epithelium. We conclude that regulating citrate concentration is essential for proper appositional growth of enamel. Full article

Legacy liquid radioactive waste (LRW) from the BN-350 sodium-cooled fast reactor is chemically heterogeneous and requires updated characterization for further management. This study investigated the physicochemical properties and gamma-emitting radionuclide composition of 13 LRW samples collected from four tanks (B-02/1, B-02/2, B-02/5, and B-02/6) at surface (“mirror”), middle, and lower levels. Five samples were analyzed as LRW and eight as evaporated LRW residues. Physicochemical analysis included pH, density, dry residue, alkalinity, and major inorganic components. Portable gamma spectrometry was applied to all samples, and laboratory HPGe measurements were performed for selected aqueous LRW samples. The saline LRW samples were strongly alkaline and highly mineralized, with dry residue values of 139.30–295.10 g/dm³. Tank B-02/6 contained distinct oil-containing, emulsion, and carbonate-rich alkaline aqueous phases. ¹³⁷Cs was the dominant identified gamma-emitting radionuclide, with specific activities ranging from (1.4 ± 0.3) × 10⁵ to (1.1 ± 0.2) × 10⁸ Bq/kg in liquid samples and up to (6.5 ± 1.3) × 10⁸ Bq/kg in evaporated residues. The results show that BN-350 LRW is not a homogeneous waste stream; therefore, future monitoring, retrieval, treatment, and conditioning should be planned according to matrix type, sampling depth, vertical phase heterogeneity, and ¹³⁷Cs-dominated radiological characteristics. Full article

Fly ash-metakaolin geopolymer has considerable potential for low-carbon and high-strength applications. However, its performance is highly dependent on preparation parameters and curing conditions, and its mix proportion optimization and nano-modification mechanism still require further clarification. In this study, under the condition that the mass ratio of metakaolin to fly ash was fixed at 9:1, an L₁₆ (4⁵) orthogonal experiment was carried out using nano-SiO₂ content, liquid-to-solid ratio, alkali equivalent, sodium silicate modulus, and curing temperature as independent variables. Range analysis and analysis of variance were employed to investigate the response patterns of slurry fluidity, setting time, and compressive strength under variations in these factors, while XRD, SEM-EDS, and FTIR were used to reveal the modification mechanism of nano-SiO₂. The results show that the early-age compressive strength is governed by alkali equivalent, whereas the later-age strength is jointly affected by multiple factors, with the differences among their effects gradually decreasing. Alkali equivalent and liquid-to-solid ratio have comparable effects on slurry fluidity, with contribution rates of 33.83% and 30.97%, respectively. Setting time is most sensitive to changes in sodium silicate modulus, which contributes 92.76% and 90.54% to the initial and final setting times, respectively. After the incorporation of an appropriate amount of nano-SiO₂, the amorphous gel characteristics, Si-O-T bonding structure, and fracture-surface compactness of the specimens were all enhanced. However, excessive incorporation tends to cause particle agglomeration and increase the water demand of the system, weakening the continuity of geopolymerization. The specimen with better overall performance was prepared with 1% nano-SiO₂, a liquid-to-solid ratio of 0.84, an alkali equivalent of 24%, and a sodium silicate modulus of 1.4, and cured at 40 °C. Full article

Background/Objectives: Meropenem is a broad-spectrum carbapenem antibiotic with demonstrated efficacy against multidrug-resistant Gram-negative pathogens. Although its use as an ophthalmic formulation is off-label, growing clinical evidence supports its application in severe ocular infections such as keratitis and endophthalmitis. However, the intrinsic instability of meropenem in aqueous solutions and the absence of standardized ophthalmic preparations limit its routine use. Furthermore, no stability studies are currently available for meropenem 50 mg/mL eye drops stored in polypropylene (PP) dropper bottles under freezing and subsequent refrigerated conditions. The aim of this study was to evaluate the physicochemical and microbiological stability of a 50 mg/mL meropenem ophthalmic solution prepared in a hospital pharmacy using a commercial meropenem pharmaceutical product, and packaged in PP containers. Methods: Eye drops were aseptically prepared from a commercially available pharmaceutical product, containing 1g de meropenem and anhydrous sodium carbonate as an excipient. After preparation, the drops were stored at −20 ± 2 °C for up to 42 days, followed by refrigerated storage (5 ± 3 °C) after thawing for up to 7 days. Chemical stability was assessed using a validated stability-indicating HPLC method in accordance with ICH guidelines and was defined as 90–110% recovery of the initial concentration. Physical stability (appearance, pH, particulate matter) and microbiological stability were also evaluated under simulated in-use conditions. Results: The HPLC method demonstrated excellent linearity, precision, and accuracy. Meropenem concentrations remained within the predefined acceptance limits throughout the 42-day study period under freezing conditions, with no significant changes in pH, color, or particulate formation. After thawing, a progressive decrease in drug concentration was observed under refrigerated conditions, falling below 90% of the initial concentration within 24–48 h. A concomitant color change from colorless to yellow was also detected, consistent with β-lactam ring hydrolysis. Despite this degradation, no significant changes in physical parameters other than color were observed, and microbiological testing confirmed sterility for up to 7 days under refrigerated conditions. Conclusions: Meropenem drops 50 mg/mL in PP dropper bottles are physicochemically and microbiologically stable for 43 days (42 days under frozen conditions plus 1 day, in-use conditions, after opening and under refrigeration). Full article