Search Results (1,719)

Garlic (Allium sativum L.) is a major horticultural crop valued for its distinctive flavor, nutritional quality, and health-promoting properties, including antioxidant and antimicrobial activities. The characteristic aroma and health benefits of garlic are primarily attributed to its organosulfur compounds. This study evaluated the effects of conventional zinc sulfate (ZnSO₄) and zinc oxide nanoparticles (ZnO NPs) on selected organosulfur metabolites in garlic bulbs using targeted liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS). Treatments comprised an untreated control, ZnSO₄, 25 mg ZnO NPs kg⁻¹ soil (ZnO NP-25), and 55 mg ZnO NPs kg⁻¹ soil (ZnO NP-50), with ten independent experimental units per treatment. Relative to the control, ZnO NP-50 increased alliin by 225.3%, allicin by 309.6%, diallyl sulfide (DAS) by 219.5%, diallyl disulfide (DADS) by 231.7%, and diallyl trisulfide (DATS) by 149.7%, whereas ajoene decreased by 67.3%. ZnO NP-50 produced the highest mean concentrations of alliin, allicin, DAS, DADS, and DATS, indicating a dose-related compositional pattern across the two nanoparticle rates. These findings demonstrate that soil-applied ZnO NPs altered the targeted organosulfur profile of garlic under greenhouse conditions. The physiological and molecular mechanisms underlying these responses were not measured and require further investigation. Full article

In membrane-based reverse electrodialysis (RED), ion-selective membranes convert ionic concentration gradients directly into electrical output. Protons are often treated within the general framework of cation selectivity, while how membrane structure specifically regulates proton transport beyond conventional cation transport remains insufficiently understood. Here, freestanding aramid nanofiber (ANF)/Ti_0.87O₂ membranes approximately 3 μm thick are prepared by co-dispersion in trifluoromethanesulfonic acid (TfOH), spin coating, aqueous regeneration, and confined drying. X-ray diffraction and two-dimensional wide-angle X-ray scattering show that Ti_0.87O₂ incorporation is accompanied by enhanced ANF ordering and preferential orientation. After normalization to the bulk HCl/KCl conductivity ratio, the proton preference factor increases from approximately 1.0 for ANF to 1.67 at a Ti_0.87O₂ mass fraction of 0.5, while the apparent activation energy is lower for HCl than for KCl transport (0.18 versus 0.24 eV). Under a 1000-fold HCl concentration gradient (1 M/0.001 M), the membrane delivers 51.52 W m⁻² and retains 88.1% of its short-circuit current over approximately 33 h. Further integration into a 10-unit stack yields an open-circuit voltage of 1.77 V, demonstrating modular voltage scaling. Together, these results suggest that Ti_0.87O₂ nanosheets promote ANF ordering and contribute to proton-favorable transport behavior. Full article

Botanical insecticides, such as essential oils, have drawn increasing interest in pest management. However, sublethal effects on exposed individuals and their offspring are often overlooked. This study evaluated the population growth of Sitophilus zeamais, Oryzaephilus surinamensis, Cryptolestes ferrugineus, and Tribolium castaneum in maize grains exposed to sublethal concentrations (1/3 and 2/3 of the LC₅₀) of Piper aduncum L. essential oil (PAEO). Population growth was assessed using daily emergence curves, total adult emergence, and grain mass loss. Sublethal PAEO exposure reduced and delayed population growth of S. zeamais, C. ferrugineus, and T. castaneum. At 2/3 of the LC₅₀, total adult emergence decreased by 42.6% in S. zeamais and 40.2% in T. castaneum compared with the control. In contrast, O. surinamensis showed an accelerated and increased emergence response, with a maximum of 10.67 ± 1.24 adults day⁻¹ at 2/3 of the LC₅₀, representing a 174.3% increase relative to the control, consistent with a possible hormetic response. These findings demonstrate species-specific responses to sublethal PAEO exposure, with population growth suppressed in three species but stimulated in O. surinamensis. This highlights the importance of appropriate dose selection to maximize pest suppression and avoid unintended stimulatory effects under stored-grain conditions. Full article

Six Centaurea cyanus L. flower extract variants were prepared using methanol, ethanol or water as a solvent; in each case, the material was either defatted with chloroform or not. The phytochemical profile of all obtained extracts was analyzed qualitatively and quantitatively using UPLC-PDA-Q/TOF-MS. In total, 35 phenolic compounds were detected, including flavonols, flavones, anthocyanins, phenolic acids and their derivatives, as well as an N-p-coumaroyl spermidine derivative; some compounds were identified using authentic standards, while others were tentatively identified based on chromatography and mass spectrometry data. The defatted ethanolic extract showed the highest total quantified phenolic content (42.18 mg/g DW), with the predominant constituents being apigenin derivatives, particularly apigenin-O-hexoside-O-glucuronide and apigenin-3-O-glucoside-(6″-acetyl)glucoside. The extract exhibited notably high antioxidant capacity, viz. DPPH (240.34 µmol TE/g), ABTS (170.53 µmol TE/g), and FRAP (189.93 µmol TE/g), and moderate antimicrobial activity, particularly against E. coli (MIC 0.5 mg/mL). The extract did not exhibit any cytotoxic effect toward L929 or Hs68 fibroblasts in vitro at concentrations up to 5 mg/mL. These findings indicate that the phenolic-rich ethanolic extract demonstrated both antioxidant and antimicrobial activities while also being non-cytotoxic against fibroblasts within the tested concentration range; as such, it may be suitable for dermatological and cosmetic formulations. Full article

Lunar soil-based geopolymers are promising in situ construction materials, but their reliance on Earth-transported alkali activators limits sustainability. This study developed a nano-SiO₂-modified simulated lunar soil-based geopolymer (NS-SLSG) with reduced activator demand by optimizing sodium hydroxide (SH), calcium hydroxide (CH), and sodium silicate (SS). Inductively coupled plasma atomic emission spectrometry (ICP-AES), orthogonal testing, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermogravimetry–differential scanning calorimetry–derivative thermogravimetry (TG-DSC-DTG), Energy-dispersive X-ray spectroscopy (EDS), and Mercury intrusion porosimetry (MIP) were used to evaluate apparent elemental-release characteristics, flowability, mechanical properties, and microstructure. The experimental results indicated that the measured Al and Si concentrations were particularly sensitive to the SH dosage; SH and SS exerted comparatively greater effects on flowability, whereas SH and CH had greater effects on mechanical performance. Adding 0.75 wt.% NS reduced the total admixture mass in the experimental formulation by 23.9% while increasing compressive and flexural strengths by 26.0% and 19.5% to 36.15 and 8.26 MPa, respectively. Microstructural results suggested that SH promoted depolymerization, while CH may have enhanced Ca²⁺-assisted polycondensation, with corresponding variations in gel composition and pore structure. These findings indicate a viable strategy for improving the resource efficiency of lunar construction materials. Full article

Background: Endotoxemia and oxidative stress may contribute to adverse body-composition changes in patients receiving maintenance hemodialysis, but their relationships with adiposity and muscularity remain incompletely defined. We investigated whether the concentrations of circulating lipopolysaccharide (LPS), soluble NOX2-derived peptide (sNox2-dp), and hydrogen peroxide (H₂O₂) showed differential associations with bioimpedance-derived body-composition compartments and explored their relationships with normalized protein catabolic rate (nPCR), a surrogate of protein intake. Methods: In this observational, cross-sectional study, adult patients receiving maintenance hemodialysis were enrolled at a single center. Serum LPS and sNox2-dp and H₂O₂ concentrations were measured before dialysis. Body composition was assessed by bioimpedance analysis; fat mass (FM) was used as an index of adiposity, whereas intracellular water indexed to height squared (ICW/h²) was used as a proxy of muscularity. Associations were examined using Spearman correlation and multivariable linear regression adjusted for age, sex, and nPCR. Results: A total of 58 participants were included with a median age of 73 years; 64% were male and mean body mass index was 24.6 ± 4.2 kg/m². LPS correlated with sNox2-dp (rho = 0.420, p = 0.001), whereas sNox2-dp correlated with H₂O₂ (rho = 0.352, p = 0.007); the LPS–H₂O₂ association was borderline (rho = 0.259, p = 0.050). sNox2-dp correlated positively with fat-free mass, total body water, ICW, and ICW/h², whereas LPS correlated with FM (rho = 0.305, p = 0.023). Participants with nPCR > 0.89 g/kg/day had higher LPS concentrations than those with lower nPCR (p = 0.015), and nPCR correlated with ICW/h² (rho = 0.36, p = 0.007). In multivariable analysis, LPS remained independently associated with FM (β = 0.210, p = 0.046). nPCR was positively associated with ICW/h² at the threshold of statistical significance (β = 1.393, p = 0.050), whereas sNox2-dp showed a nonsignificant positive trend (p = 0.060). Conclusions: In maintenance hemodialysis, endotoxemia and NOX2 activation showed differential associations with body composition: LPS with adiposity and sNox2-dp with muscularity. Higher nPCR was associated with both greater muscularity and higher LPS concentrations, suggesting a complex relationship between protein intake, the gut–oxidative-stress axis, and body composition. Full article

Background/Objectives: Origanum bilgeri P.H. Davis is a Turkish endemic Lamiaceae species whose non-volatile phenolic composition and organ-specific bioactivities remain unexplored. This study investigated the phenolic composition of flower, leaf, stem, and root extracts and evaluated their antioxidant and enzyme-inhibitory activities. Methods: Ultrasound-assisted ethanolic extracts of the four organs were characterized by liquid chromatography–tandem mass spectrometry (LC–MS/MS) targeting 28 phenolic compounds. Total phenolic and flavonoid contents, outcomes of six antioxidant assays, and inhibitory activities against acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-amylase, and α-glucosidase were determined. Measurements were performed in triplicate as technical replicates, and organ-level differences were interpreted descriptively. The relative antioxidant capacity index (RACI) was calculated from the standardized outcomes of the six direct antioxidant assays, with total phenolic content (TPC) and total flavonoid content (TFC) excluded from the index. Pearson correlation analysis and principal component analysis (PCA) were used for exploratory evaluation of phytochemical and bioactivity patterns. Results: Twenty phenolic compounds were detected in at least one organ. Rosmarinic acid predominated in all organs and was most abundant in the leaf (3236 µg/g extract) and stem (3093 µg/g extract), whereas the root was markedly enriched in verbascoside (2775 µg/g extract) and chlorogenic acid (1461 µg/g extract) and exhibited the highest total phenolic content, reaching 160.87 mg gallic acid equivalents (GAE)/g extract. The assay-based RACI ranked the root highest (0.54), followed by the stem (0.02), leaf (−0.27), and flower (−0.30). The root also showed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (half-maximal inhibitory concentration, IC₅₀ = 0.28 mg/mL) and cupric reducing antioxidant capacity (CUPRAC) (half-maximal effective concentration, EC₅₀ = 0.22 mg/mL) among the investigated organ extracts. Under the present assay conditions, all organ extracts yielded lower α-glucosidase IC₅₀ values (0.97–1.10 mg/mL) than acarbose (1.16 mg/mL). Exploratory Pearson correlation analysis indicated strong organ-level covariation among several antioxidant parameters, phenolic constituents, and α-glucosidase inhibitory activity. PCA based on the Pearson correlation matrix showed that principal components 1 and 2 (PC1 and PC2) accounted for 50.73% and 38.49% of the total variance, respectively (cumulative variance: 89.22%), providing an exploratory visualization of the multivariate organization of phytochemical and bioactivity variables. Conclusions: O. bilgeri exhibited distinct organ-specific phytochemical and bioactivity patterns under the conditions investigated. The root was particularly characterized by high verbascoside and chlorogenic acid contents, elevated total phenolic content, strong antioxidant performance across several assays, and α-glucosidase inhibitory activity. These findings support further investigation of O. bilgeri, particularly its root, using independent biological replicates and complementary phytochemical and biological approaches. Full article

Rhododendron decorum Franch. has high ornamental value and emerging edible potential, but conventional propagation cannot meet the demand for high-quality, genetically uniform planting stock. This study optimized explant disinfection, adventitious bud induction, shoot proliferation, and rooting culture using stem segments and leaves from a winter-flowering naturally mutated individual of Rhododendron decorum, aiming to minimize contamination and browning. Results demonstrated that combined disinfection with 1% KMnO₄ (10 min) and 10% H₂O₂ (4 min) outperformed single-treatment with 0.1% HgCl₂. For primary culture, the optimal medium for adventitious bud induction was WPM + 30 g·L⁻¹ sucrose + 7.5 g·L⁻¹ agar + 0.56 g·L⁻¹ Ca(NO₃)₂ + 100 mg·L⁻¹ VC + 3 mg·L⁻¹ TDZ + 0.1 mg·L⁻¹ NAA, achieving an induction rate of 66.67%. During subculture, when the concentrations of TDZ and NAA were adjusted to 0.6 mg·L⁻¹ and 0.05 mg·L⁻¹, respectively, and 2 mg·L⁻¹ GA₃ was supplemented, stem nodes exhibited slight thickening but no significant shoot elongation. For rooting, the basal medium WPM + 20 g·L⁻¹ sucrose + 7.5 g·L⁻¹ agar + 0.56 g·L⁻¹ Ca(NO₃)₂ + 100 mg·L⁻¹ VC + 1 g·L⁻¹ activated charcoal supplemented with 0.8 mg·L⁻¹ NAA yielded superior rooting performance. Adding 2 mg·L⁻¹ 2iP tended to enhance rooting rate relative to the NAA-only treatment from an independent rooting experiment. For callus-mediated bud induction from leaves, 0.1 mg·L⁻¹ TDZ + 0.01 mg·L⁻¹ NAA was optimal. Notched fully expanded apical leaves from tissue-cultured plantlets showed highest adventitious bud induction under 0.3 mg·L⁻¹ TDZ + 0.01 mg·L⁻¹ NAA. The established micropropagation system supports bud sport variety selection, mass seedling production, and genetic transformation research. Full article

Soil microplastic pollution may affect woody plant establishment, but evidence for tree seedlings remains limited. Populus simonii × P. nigra ‘1307’ seedlings were grown for 45 d in soil containing an equal-mass PVC–PE–PS mixture at 0, 100, 500, or 1000 mg kg⁻¹ dry soil. Growth, root architecture and activity, photosynthetic traits, oxidative status, and soil chemical and enzymatic properties were measured. The 100 mg kg⁻¹ treatment produced limited, trait-specific changes and did not consistently inhibit growth. In contrast, 500 and 1000 mg kg⁻¹ reduced most growth and physiological traits. At 1000 mg kg⁻¹, total dry biomass, total root length, root surface area, root volume, root-tip number, and root activity decreased by 43.7%, 46.5%, 47.2%, 50.2%, 51.1%, and 50.9%, respectively. Net photosynthetic rate and PSII electron transport declined, whereas H₂O₂, O₂•⁻ production, thiobarbituric acid-reactive substances (TBARS), and electrolyte leakage increased. Under higher exposure, soil electrical conductivity was higher, whereas available nutrient levels and several soil enzyme activities were lower. These results indicate that medium and high concentrations of the tested mixture were associated with concurrent inhibition of root development, photosynthetic performance, and biomass accumulation under short-term pot conditions. Because concurrent impairment of woody-seedling performance and soil biochemical functioning may compromise vegetation establishment, these findings support the inclusion of mixed-polymer exposure in ecological risk assessments for soils used in forestry and ecological restoration. Full article

Graphene oxide (GO) offers a high-surface-area platform for the noncovalent association of hydrophobic bioactive compounds, but its biological response depends strongly on surface chemistry. Here, GO was carboxylated with sodium chloroacetate and physically associated with curcumin (CUR) to obtain a graphene oxide–curcumin nanoadduct (GO-COOH-CUR). Ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to assess chemical and morphological changes. XPS showed a lower C/O ratio and a higher fitted O-C=O contribution after carboxylation, although residual Na and Cl were detected. UV-vis, FTIR and XPS features were consistent with the presence of curcumin in the formulation with 83.35% of encapsulation efficiency (EE). In 24 h MTT assays, CO-COOH-CUR maintained BHK-21 metabolic activity above 70% across 3.125 µg mL⁻¹ and reduced MCF-7 metabolic activity at the higher tested concentrations. Because formulation concentrations were expressed as a total mass and curcumin concentration is not reported here, direct potency or selectivity comparisons with free curcumin were not made. Qualitative histological evaluation performed 30 days after subdermal implantation in three male Wistar rats showed preserved adjacent tissue architecture, with no evident necrosis, prominent inflammatory infiltrate, organized fibrous capsule, or foreign-body giant cell response in the sections evaluated. These findings support further evaluation of GO-COOH-CUR within the limits of MTT-based and qualitative assessment. Full article

Eastern Croatia includes settlements with historically elevated arsenic (As) concentrations in drinking water. Of 488 recruited adults, nine were excluded solely because no questionnaire was available; the exclusion was independent of measured arsenic concentrations, and the harmonised analytical cohort therefore comprised 479 adults from eight settlements. Total As concentrations in drinking water, hair, serum, and urine were measured in samples collected in June 2015 by inductively coupled plasma mass spectrometry. Kidney cancer data (ICD-10 C64) for 2000–2018 were obtained from the Croatian National Cancer Registry and analysed ecologically. MDCK1 cells were exposed to As₂O₃ at 10–200 µg/L for 48, 72, and 96 h, and acetylcholinesterase (AChE) activity was measured in human erythrocytes. Čepin had the highest median As concentrations in drinking water (191.75 µg/L) and urine (68.14 µg/L). Across all eight settlements, drinking-water As was strongly associated with urinary As (slope = 0.537; 95% CI, 0.352–0.722; R² = 0.894; p < 0.001). However, in a sensitivity analysis excluding Čepin and using the seven non-Čepin settlement means reported, the association weakened (r = 0.740; R² = 0.548; slope = 1.246; 95% CI, −0.054 to 2.547; p = 0.057), indicating substantial influence of the Čepin hotspot. Associations with hair As (R² = 0.294; p = 0.165) and serum As (R² = 0.239; p = 0.219) were not statistically significant. In a multivariable Gamma generalized linear model, residence in Čepin was associated with higher expected urinary As than residence in Vladislavci (adjusted mean ratio, 2.90; 95% CI, 1.90–4.42; p < 0.001), while female sex was associated with a lower expected concentration (adjusted mean ratio, 0.80; 95% CI, 0.66–0.97; p = 0.024). No statistically significant effect of As₂O₃ on MDCK1 viability or erythrocyte AChE activity was observed. The findings support urinary total As as a biomarker of recent environmental exposure, but do not establish causal associations with kidney toxicity or kidney cancer. Full article

The effect of Co₃O₄ concentration on the phase composition, surface morphology, geometric density, estimated porosity, compressive strength, and resistive superconducting transition of YBa₂Cu₃O_7−δ ceramics was comparatively investigated. Undoped YBa₂Cu₃O_7−δ and Co₃O₄-modified YBa₂Cu₃O_7−δ ceramics containing 0.1, 0.5, 1.0, and 1.5 wt.% Co₃O₄ were prepared from the same nonstoichiometric Y–Ba–Cu–O precursor mixture by a solid-state reaction route followed by oxygen annealing. Phase composition was evaluated by X ray diffraction, surface morphology by scanning electron microscopy, geometric density from specimen mass and dimensions, compressive strength by uniaxial compression, and superconducting transition parameters by four probe electrical resistance measurements. The YBa₂Cu₃O_7−δ phase remained the dominant crystalline phase in all specimens. The sample containing 0.1 wt.% Co₃O₄ exhibited the highest YBa₂Cu₃O_7−δ content among the modified specimens, 65.2 wt.%, the highest measured compressive strength of 1.95 MPa, and the highest onset transition temperature of 95 K. The highest geometric density of 5.36 g/cm⁻³ and the lowest estimated porosity of 15.3% were obtained at 0.5 wt.% Co₃O₄. The specimens containing 1.0 and 1.5 wt.% Co₃O₄ showed lower YBa₂Cu₃O_7−δ phase fractions and lower geometric density, and did not reach the zero-resistance state within the available measurement range. Although the 0.1 wt.% specimen exhibited a higher onset temperature than undoped YBa₂Cu₃O_7−δ, its lower zero-resistance temperature and broader transition indicate that Co₃O₄ did not improve all superconducting parameters simultaneously. Since only one specimen was tested for each composition, the density and compressive strength trends should be regarded as preliminary. Full article

Hydrogen transport and cyclic loading complicate O-ring assessment. This study developed an automated sequential screening workflow for ethylene–propylene–diene monomer (EPDM) O-rings, linking Abaqus mass diffusion, one-way concentration-field transfer to nonlinear structural/contact analysis with prescribed isotropic swelling, and fe-safe/Rubber fatigue post-processing. EPDM 60A and 90A were evaluated at sampled pressures of 3, 7, 14, and 21 MPa and circumferential installation stretches of 1–5%, with radial squeeze fixed at 20%. Structural analyses used third-order Reduced Polynomial models with built-in Mullins effects. Material-specific diffusivities characterized at approximately 1 bar were held constant across pressures; hydrogen-content and post-decompression free-specimen volume-change data informed model inputs. Fatigue inputs were characterized in air at approximately 23 °C using non-equivalent bases for the two compounds. At 1% stretch, fatigue-life outputs decreased from 6.877 × 10⁷ to 12.923 repeats for 60A and from 3.155 × 10⁹ to 3.896 repeats for 90A between 7 and 14 MPa. At 21 MPa, outputs were 0.712 and 0.041 repeats, respectively; these fractional values are numerical screening indicators without assignment to a within-cycle event or damage mode. The outputs support only input-conditional comparison of axisymmetric cases and experimental prioritization; they do not support decisions on component durability, leakage, sealing performance, or operating pressure. Full article

High-resolution air pollutant measurement in Antarctica remains limited, particularly for short-term variability and episodic enhancements associated with local field activities, atmospheric processes, and long-range transport. This study presents minute-scale observations of trace gases and particulate matter collected during a short Antarctic field campaign from May to June 2023. The dataset includes NO₂, O₃, CO, SO₂, PM_2.5, and PM₁₀, with supplementary total volatile organic compound (TVOC) measurements available for May. Raw observations were quality-organized, aggregated to hourly and daily means, and examined for temporal variability, diurnal behavior, pollutant relationships, and short-duration pollution events. Across 58,652 valid observations, surface O₃ showed relatively stable concentrations compared with the other pollutants, while NO₂, CO, SO₂, PM_2.5, and PM₁₀ displayed episodic enhancements. Median concentrations were 11.05 ppb for NO₂, 38.17 ppb for O₃, 30.61 ppb for CO, 0.01 ppb for SO₂, 6.29 µg m⁻³ for PM_2.5, and 7.29 µg m⁻³ for PM10. PM2.5 and PM10 were strongly correlated, with a median PM_2.5/PM₁₀ ratio of approximately 0.96, suggesting that fine particles contributed substantially to particulate mass during much of the campaign. Event detection based on pollutant-specific hourly 95th percentile thresholds identified 142 single-pollutant enhancement events and 30 multi-pollutant concurrent events. TVOC observations were highly zero-inflated, with only about 1.9% nonzero readings and a short-lived elevated episode around 9 to 10 May; therefore, TVOC was treated as ancillary and interpreted cautiously. These results demonstrate that even short Antarctic field campaigns can capture meaningful high-resolution pollutant variability and episodic enhancements. Because reference-grade co-location was not available under Antarctic conditions, the reported concentrations are interpreted as calibrated sensor estimates, with emphasis placed on temporal variability rather than reference-equivalent absolute concentrations. The results apply only to the May–June 2023 campaign and are not intended to represent seasonal, annual, continent-wide, or long-term Antarctic air quality; they provide useful observational evidence of short-term atmospheric variability in a remote polar environment and highlight the importance of transparent event detection and cautious interpretation of short-duration sensor records. Full article

As a critical strategic resource in the 21st century, the efficient separation of lithium poses a major challenge in mineral processing. To address the issue of the low flotation separation efficiency caused by the similar surface properties of spodumene, lepidolite, and gangue minerals such as feldspar, this study systematically investigates the effects and mechanisms of NaOH/Na₂CO₃ mixed alkali pretreatment on the flotation behavior of the three minerals. The results show that pretreatment with a specific mass ratio of mixed alkali (NaOH:Na₂CO₃ = 5:2) can significantly enhance the flotation recovery of spodumene and lepidolite, while having minimal impact on the recovery of feldspar. After mixed alkali pretreatment, the flotation recovery of spodumene rises from less than 10% to 87.90%, and lepidolite recovery increases from below 10% to 90.1%, whereas feldspar recovery remains lower than 14% throughout the tests. Mechanistic analysis reveals that the mixed alkali system selectively promotes the breakage of Al-O bonds on the surfaces of lithium minerals, accelerating the differential dissolution of Al and Si, which leads to a decrease in the Al/Si ratio on the mineral surfaces and the formation of Al-enriched active sites. Meanwhile, Na₂CO₃ plays a selective regulatory role by adjusting the interfacial ionic environment and suppressing excessive attack by OH⁻. XPS analysis indicates a significant increase in the proportion of high-binding-energy Al species on the surfaces of lithium minerals after pretreatment, with no obvious changes observed on the feldspar surface. SEM-EDS and XRD confirm the cleaning, modification, and secondary precipitation behavior of the mineral surfaces induced by the pretreatment. Specific surface area analysis further demonstrates that moderate alkali etching reduces the surface energy and porosity of lithium minerals, facilitating subsequent collector adsorption. The bench-scale closed-circuit flotation of real complex lithium ore (1.21% Li₂O) finally yields lithium concentrate grading of 5.52% Li₂O with a Li₂O recovery of 76.82%. This study deepens the understanding of the interfacial reaction mechanisms of lithium minerals under alkaline conditions and provides theoretical support for the development of efficient and environmentally friendly flotation processes for lithium ores. Full article