Search Results (541)

Salvia officinalis L. is a pharmaceutically important species rich in rosmarinic acid, yet strategies to enhance phenolic accumulation in controlled systems remain limited. This study compared three elicitor categories on polyphenol biosynthesis in Agrobacterium rhizogenes-transformed hairy root cultures: chemical (salicylic acid, AgNO₃), physical-Light-emitting diode (LED light spectra: white, blue, red, green, darkness), and biological (Bacillus velezensis BPVs2cell lysate and cell-free supernatant, Trichoderma asperellum TdCP biomass lysate). Within the chemical-elicitation series, AgNO₃ produced the strongest response, increasing total phenolic content by 39.2% after 7 days compared with the untreated control and inducing an approximately three-fold increase in rosmarinic acid, together with elevated levels of caffeic, syringic, and chlorogenic acids. Salicylic acid exhibited an inhibitory effect, decreasing total phenolic content by 50%. Exposure to blue and red LED light resulted in a two-fold increase in total phenolics compared with white light and darkness, while green light uniquely stimulated the exudation of phenolics into the culture medium. Among biological elicitors, B. velezensis cell-free supernatant (1.5 mL) triggered a 10-fold increase in rosmarinic acid at day 7, whereas T. asperellum produced a transient, non-specific response without targeted rosmarinic acid enhancement. These results demonstrate that elicitor type, dose, and exposure time critically determine phenolic accumulation specificity. AgNO₃, blue and red LED illumination, and B. velezensis cell-free supernatant were identified as promising individual treatments in their respective experimental series; however, combined-treatment effects and possible synergism require confirmation in a factorial experiment. Full article

Self-adhesive flowable resin composites have been developed to simplify restorative procedures by eliminating separate adhesive application; however, their gingival sealing to dentin remains a concern. This study assessed the gingival marginal sealing of resin composites by measuring silver nitrate solution (AgNO₃) penetration using micro-computed tomography (µCT). Materials and Methods: Seventy-five human third molars with 150 standardized cavities were allocated into 15 experimental groups based on three surface pretreatments (no pretreatment, sodium hypochlorite solution [NaOCl], and a hypochlorous acid-containing aqueous solution [HCS]) and five restorative materials: three self-adhesive flowable composites (Fusio Self-Adhesive, Vertise Flow, and Nova Compo SF) and two conventional composites (Clearfil Majesty Posterior and Clearfil Majesty Flow). Following thermal cycling, microleakage was quantified by measuring silver nitrate penetration along the gingival floor of the restorations using µCT and statistically analyzed. Results: HCS significantly reduced silver nitrate penetration in all self-adhesive composites (p < 0.05), while NaOCl significantly reduced silver nitrate penetration only in the 10-MDP-containing Nova Compo SF (p < 0.05). Conventional composites bonded with a self-etch adhesive exhibited significantly lower microleakage than self-adhesive materials (p < 0.05). Conclusions: HCS improved the gingival marginal sealing of self-adhesive flowable composites to dentin, whereas the effect of NaOCl was material-dependent. Conventional resin composites used with a self-etch adhesive demonstrated superior gingival marginal sealing compared with self-adhesive flowable composites. Full article

This study focuses on Siraitia grosvenorii, an economically important crop endemic to Guangxi Province, China, with significant value in both the pharmaceutical and food industries. However, its dioecious reproductive system results in low natural pollination efficiency, necessitating reliance on costly artificial pollination in commercial production, which severely constrains large-scale cultivation and the breeding of improved varieties. Herein, we systematically investigated the molecular mechanisms of silver nitrate (AgNO₃)-induced partial masculinization of female flowers, resulting in the formation of morphologically bisexual flowers with aborted stamens. Morphological observations revealed that untreated female flowers exhibited permanently arrested stamen primordia, whereas spraying treatments with 0–300 mg/L AgNO₃ triggered the development of morphologically complete bisexual flowers. Nevertheless, AgNO₃-induced stamens exhibited severely disrupted male reproductive development, as indicated by the absence of mature pollen grains at anthesis. Cytological evidence demonstrated that pollen abortion was initiated at the pollen mother cell (PMC) stage, accompanied by abnormal vacuolation and impaired nutrient metabolism in tapetal cells. The dominant abortive phenotype was that PMCs exhibited abnormal development and progressive degeneration during the meiotic developmental window. Methylation-sensitive amplification polymorphism (MSAP) assays further revealed markedly elevated CpG-type methylation levels in AgNO₃-induced bisexual flowers at early developmental stages. Expression analysis revealed that SgWIP1 exhibited distinct temporal expression patterns among female, male, and AgNO₃-induced bisexual flowers, with reduced expression during later stages of stamen development in induced bisexual flowers. Collectively, our findings confirm that AgNO₃ only partially activates the stamen developmental cascade in S. grosvenorii. Extensive epigenetic reprogramming triggered by AgNO₃, together with the inability to sustain the expression of core male-determining genes, is tightly linked to tapetal dysfunction and subsequent pollen sterility. This study aims to elucidate the unique mechanism by which AgNO₃-induced partial masculinization in S. grosvenorii from multiple perspectives—including tissue and cellular structure, DNA methylation epigenetic modifications, and gene transcription regulation—using techniques such as morphoanatomy, histochemistry, epigenetics (MSAP), and gene expression analysis. The findings of this study will contribute to molecular breeding efforts focused on sex regulation and promote industrial development. Full article

This study aims to comprehensively investigate the usability of white mulberry (Morus alba L.) leaf extract as a natural dye, including its fastness properties, antibacterial activity, and antioxidant activity. In the study, dyeing processes were carried out on cotton fabric, wool fabric, wool yarn, polyester, leather, and pine wood materials using different mordanting techniques (pre-, co-, and post-mordanting) and pH values (4 and 8). Copper-II-sulfate, iron-II-sulfate, alum, silver nitrate, Reşadiye clay, and Önal-1 [3% (v/v) NH₃ + 3% (w/v) Urea + 3% (w/v) CaC₂O₄] were used as mordants. Washing, light, rubbing, and perspiration fastness of the dyed materials were evaluated according to international standards, and color properties were analyzed using the CIE-Lab* system and Kubelka–Munk (K/S) values. Structural characterization of the extract was carried out using 1H-NMR, 13C-NMR, LC-MS/MS, and TLC. Antibacterial activity of the dyed materials was assessed using the disk-diffusion method, with undyed, extract-only, and mordant-only controls used to distinguish the contributions of the extract and the mordants. Ferric reducing antioxidant power (FRAP) evaluation across six solvent fractions revealed marked solvent-dependent efficacy, with the apolar hexane fraction exhibiting the highest reducing capacity (436.3 ± 12.45 µmol TE/g fw), followed by the chloroform (423.83 ± 11.76 µmol TE/g fw) and hexane/ethyl acetate (406.98 ± 10.23 µmol TE/g fw) fractions, whereas the polar methanol fraction showed the lowest reducing capacity (100.76 ± 4.32 µmol TE/g fw). This reducing potential was statistically associated with the enriched flavonoid and phenolic core constituents identified via LC-MS/MS, primarily hesperidin (8.365 ± 0.432 mg/g) and isoquercetin (0.645 ± 0.054 mg/g). Because only the single-electron-transfer FRAP assay was performed, no radical-scavenging (IC₅₀) metrics are reported. The reducing capacity is therefore interpreted cautiously as a collective property of the phenolic–flavonoid fraction, in which hesperidin and isoquercetin are the principal contributors rather than any single decisive compound. The results revealed that white mulberry leaf extract exhibited high K/S values (21.33 for cotton fabric and 27.91 for wool yarn) and excellent antibacterial activity, particularly when a silver nitrate mordant was used. LC-MS/MS analysis confirmed the presence of bioactive compounds, including hesperidin (8.365 mg/g), isoquercetin (0.645 mg/g), and vanillic acid (0.189 mg/g) in the extract. These findings indicate that white mulberry leaf extract is a plant-derived colorant with multifunctional potential for textile, leather, and wood substrates. The present work does not quantify the environmental footprint of the complete process; therefore, no overall sustainability advantage relative to conventional dyeing is claimed. Any future environmental assessment should include measured extraction energy, water consumption, mordant loading, residual-metal concentrations in spent baths, and wastewater-treatment requirements. Full article

The development of sensitive, low–cost, and visually readable dosimeters for low gamma–ray exposures is important for occupational and environmental radiation monitoring and for other low–dose applications. This work investigates a colorimetric and optical thin–film dosimeter based on polyvinyl alcohol (PVA) containing silver nitrate (AgNO₃) and hafnium oxide (HfO₂). The film was fabricated using a solution–casting technique. The dosimetric response was evaluated over an absorbed–dose range of 22.2–65.2 mGy using diffuse reflectance spectroscopy, Kubelka–Munk (K/S) analysis, CIELAB colorimetry, CMYK image–based analysis, and X–ray diffraction (XRD). Irradiation produced a dose–dependent decrease in visible reflectance and a corresponding increase in optical absorption. The K/S response increased with dose, while CIELAB analysis showed a systematic decrease in lightness and an increase in total color difference (${\Delta \mathrm{E}}_{ab}^{\ast }$), reaching approximately 25 at 65.2 mGy. Linear regression of ${\Delta \mathrm{E}}_{ab}^{\ast }$ over 0–65.2 mGy gave y = 0.399x − 1.0029 with R² = 0.9845. CMYK analysis also showed a clear dose response, with the yellow channel (ΔY) exhibiting the largest relative change among the chromatic channels. XRD identified monoclinic HfO₂ as the dominant crystalline filler phase and showed dose–associated changes in peak intensity, peak position, and the relative prominence of the broad PVA–related feature. At the highest XRD dose, several HfO₂ reflections weakened while the broad contribution near 2θ ≈ 19.9–20° became more prominent. These changes are interpreted as dose–dependent structural modification and partial loss of resolved crystalline order rather than definitive evidence of a newly formed crystalline phase. A surface morphology and microstructure analysis was performed on control and γ–ray–irradiated PVA/HfO₂/AgNO₃ nanocomposite films using scanning electron microscopy (SEM–EDX). The morphological transition to fibrous, tree trunk–like structures seen by SEM is well correlated with the dose–dependent change in composition to higher surface Ag content, supporting the idea that radiation–induced Ag nanoparticle nucleation and growth is the primary degradation mechanism in the irradiated films. The combined optical and colorimetric results demonstrate a measurable response of the PVA/HfO₂/AgNO₃ formulation in the investigated low–mGy gamma–ray range. Full article

The unauthorized addition of silver nitrate and excessive heavy metals in hair dye creams poses serious health risks, creating an urgent need for rapid and sensitive detection methods. In this study, a spark discharge-enhanced fiber laser-induced breakdown spectroscopy (SD-LIBS) system was developed for the simultaneous detection of five heavy metal ions (Ag, Pb, Cd, As, Hg) in hair dye creams. The system combines three signal enhancement strategies: high-voltage spark discharge, Au nanoparticle-assisted enhancement, and analyte enrichment on a superhydrophobic–hydrophilic patterned graphite substrate. Hydrophilic micro-pits were fabricated by laser scanning on the superhydrophobic graphite surface to confine and concentrate analyte residues upon droplet drying. Under optimized discharge conditions of 22 nF and 2000 V, the spark discharge achieved a signal-to-noise ratio enhancement of approximately 12 times. Au nanoparticle enhancement further increased the signal intensity by 49.3%. The optimal pit diameter and sample loading volume were 0.1 mm and 30 μL, respectively. The calibration curves for all five elements showed good linearity with R² values close to 0.99, and the lowest detection limits reached 1.9 μg/L for Ag. The average spiked recovery was 82.07%. The method was applied to four commercial hair dye cream samples, and the Ag detection results agreed well with ICP-OES reference values with an average error of 16.41%. This work demonstrates that the proposed SD-LIBS system offers a low-cost, rapid, and sensitive approach for on-site screening of heavy metals in cosmetics and other consumer products. Full article

This study describes the microstructural and chemical characteristics of luster glazes applied to white clay and chamotte clay bodies using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS) and X-ray diffraction (XRD). Surface and cross-sectional analyses were performed to evaluate glaze morphology, the glaze–body interface, and the formation of metallic phases responsible for the luster effect. SEM observations indicated that the glaze applied to the white clay body exhibited greater thickness uniformity and a well-defined transition zone. In contrast, the chamotte clay body, due to its higher porosity, showed a more heterogeneous glaze distribution and increased interfacial irregularities. EDS analyses revealed the localized distribution of metallic elements, particularly silver and copper, and demonstrated the influence of body composition on glaze–body interactions. XRD results confirmed the presence of silver- and copper-rich crystalline phases on the glaze surface. Overall, the results demonstrate that the optical and esthetic performance of luster glazes depends on both glaze formulation and the microstructural properties of the ceramic body, providing relevant insights for optimizing artistic and industrial applications. Full article

The printing adaptability and sintering compactness of photovoltaic back silver paste are highly dependent on the physical properties of the silver powder, such as tap density and particle size distribution, which in turn are directly influenced by the purity of the precursor silver nitrate. When using 4N silver ingots as the raw material, trace impurities such as Nb, Fe, Cu, and Pb remaining in the crude solution can seriously interfere with the uniform nucleation and growth of silver crystallites, leading to decreased tap density and broadened particle size distribution. This paper presents a combined impurity removal–crystallization process integrating an adsorbent with controlled evaporative crystallization. Under optimized conditions, the concentrations of Nb, Fe, Cu, and Pb impurities decreased from 44, 21, 16, and 12 ppm to below 4 ppm, respectively. Meanwhile, the controlled crystallization step further enhanced the purity of the silver nitrate crystals through the redistribution of impurities between the solid and liquid phases. When the high-purity silver nitrate prepared by this process was used to produce photovoltaic back silver powder, the tap density of the resulting silver powder increased from 2.5 g cm⁻³ to 3.4 g cm⁻³, accompanied by a smooth surface morphology. Thermogravimetric (TG) analysis further confirmed a lower residual organic content on the particle surface. These comprehensive improvements in powder properties demonstrate the effectiveness of the proposed process in producing high-quality silver powder for photovoltaic back silver applications. Full article

Background/Objectives: Plant-mediated silver nanoparticles (AgNPs) are promising components for oral biomaterials because of their antimicrobial potential; however, their biological behavior depends strongly on the phytochemical matrix, physicochemical characteristics, and exposure concentration. This study aimed to evaluate silver nanoparticles formulations synthesized using turmeric powder-derived Curcuma longa ethanolic and aqueous extracts, with emphasis on physicochemical characterization, antibacterial activity against oral-relevant Gram-positive bacteria, cytocompatibility toward human gingival fibroblasts (HGF-1), and acute in ovo vascular compatibility. Methods: AgCUR-EtOH NPs and AgCUR-H₂O NPs were synthesized using CUR-EtOH and CUR-H₂O extracts as reducing and stabilizing matrices. The resulting formulations were characterized by UV–visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta-potential analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined against Streptococcus mutans, Streptococcus oralis, and Staphylococcus aureus. Cytocompatibility was evaluated in HGF-1 human gingival fibroblasts after 24 h exposure to 1–10 µg/mL using complementary viability, lysosomal, mitochondrial, and fluorescence-based assays. Acute vascular irritation was assessed using the hen’s egg test–chorioallantoic membrane (HET-CAM) assay. Results: Both formulations exhibited broad, polydisperse hydrodynamic distributions and negative apparent zeta potentials. AgCUR-H₂O NPs showed a lower Z-average diameter than AgCUR-EtOH NPs under their respective solvent-specific measurement conditions. XRD pattern revealed heterogeneous crystalline compositions dominated by residual AgNO₃, together with weaker contributions consistent with metallic Ag and a possible minor oxidized silver phase. FTIR spectra demonstrated extract-derived organic functional groups and prominent nitrate-associated bands. TEM/EDX confirmed Ag-containing nanostructures with approximate size ranges of 15–175 nm for AgCUR-EtOH NPs and 15–150 nm for AgCUR-H₂O NPs. S. mutans was the most susceptible microorganism, with MIC values of 9 and 7 µg/mL and MBC values of 88 and 62 µg/mL for AgCUR-EtOH NPs and AgCUR-H₂O NPs, respectively. AgCUR-H₂O NPs consistently showed lower MIC and MBC values against all tested strains, but also produced a more pronounced concentration-dependent reduction in HGF-1 viability. At 10 µg/mL, cell viability was 71.88% for AgCUR-EtOH NPs and 52.14% for AgCUR-H₂O NPs. Both formulations showed low acute irritation potential in ovo, with irritation scores of 1.06 and 0.69, respectively. Conclusions: The two CUR-AgNP formulations exhibited distinct physicochemical, antibacterial, and cellular response profiles under the tested conditions. At equivalent concentrations expressed as total dried formulation mass, AgCUR-H₂O NPs yielded lower MIC and MBC values against the tested bacterial strains, whereas AgCUR-EtOH NPs produced a less pronounced reduction in HGF-1 viability. Because the powders were not quantitatively normalized for total silver, extract-derived organic fraction, or residual precursor content, these differences cannot be attributed exclusively to nanoparticle properties or to the extraction solvent and should not be interpreted as evidence of the intrinsic superiority of either formulation. Both formulations showed low acute vascular irritation. Further quantitative compositional, silver-release, and biofilm assessments are required before incorporation into oral biomaterial platforms. Full article

Occlusal pits and fissures remain the most vulnerable tooth surfaces for caries initiation, and selecting a sealant that seals these areas reliably is a clinically meaningful question. We investigated the internal adaptation of four pit and fissure sealants—two resin-based and two glass ionomer-based—applied to permanent premolar teeth. Forty extracted premolars were randomly assigned to four groups (n = 10): Group 1, BeautiSealant (BS); Group 2, 3M Clinpro Sealant; Group 3, GC Fuji IX without surface coating; and Group 4, GC Fuji IX with G-Coat Plus. Following 15,000 thermal cycles, internal adaptation was assessed by X-ray microtomography (micro-CT) using silver nitrate as a tracer. No statistically significant difference was found in the overall mean gap volumes between groups (p = 0.774). The 3M™ Clinpro™ Sealant group exhibited the lowest mean gap value (3.45 ± 1.71), followed by BeautiSealant (3.89 ± 1.34) and GC Fuji IX GP^® with G-Coat Plus™ (4.93 ± 4.09), whereas the GC Fuji IX GP^® without coating group showed the highest mean value (5.56 ± 5.35). Resin-based sealants achieved better fissure penetration and marginal adaptation than the glass ionomer formulations tested, though the differences did not reach statistical significance under the conditions of this study. Full article

Among the micropollutants of medium-depth waters in isolated inhabited areas, the inorganic ones deserve special attention: nitrate anion (NO₃⁻) and phosphate anions (HxPO₄^−(3−x)). The individual removal of these anions from water is widely studied, with different methods being found: chemical, ion exchange, or biological. This paper presents a membrane method for the simultaneous removal of nitrate anion and phosphate anions from dilute synthetic aqueous solutions. The developed method is nanofiltration using composite membranes made of cellulose acetate (CA) and silver nanoparticles (Agnp). The composite membranes were made by phase inversion of the dimethylformamide (DMF) solution containing the two components (CA–Agnp) on a polypropylene (PP) capillary fiber using deionized water as a coagulant. The DMF solution of CA containing Agnp was obtained by dissolving black-and-white cinematographic films (exposed and unexposed to light). CA–Agnp–PP composite membranes were tested for the simultaneous removal of nitrate anion and phosphate anions from aqueous solution by nanofiltration at pressures ranging from 5 to 25 bars. A removal of over 98% of phosphate anions and more than 95% of nitrate anions was achieved. Fluxes of 10 L·m⁻²·h⁻¹ were obtained for the working pressure of 15 atm, depending on the pH, flow rate, and concentration of the feed water. The variable parameters considered were also the concentrations of CA and Agnp. Full article

Nanoemulsions are promising nanotechnology-based delivery systems that may improve the stability, bioavailability, and cellular uptake of therapeutic agents. Silver nanoparticles (AgNPs) have been reported to exhibit high antibacterial and anticancer activities via several mechanisms, such as the generation of oxidative stress and disruption of cellular membrane integrity. Breast cancer (MCF−7) and ovarian cancer (SK-OV−3) represent two highly aggressive malignancies that pose major global health challenges. Brown algae oil is a natural marine-derived product with a number of bioactive compounds, including fatty acids, sterols, and antioxidants, responsible for its numerous biological activities. Oil extracted from the brown alga Turbinaria turbinata, using hexane as an organic solvent, was formulated with silver nitrate (AgNO₃) using a surfactant-stabilized spontaneous emulsification method to prepare a silver-loaded T. turbinata oil nanoemulsion (Ag-TTO-NE). The biological performance of the system was evaluated against human cancer cell lines, including MCF−7 (breast cancer) and SK-OV−3 (ovarian cancer), in addition to pathogenic bacterial strains, and for antioxidant activity. The results demonstrated that the silver-loaded oil nanoemulsion (Ag-TTO-NE) exhibited anticancer activities against MCF−7 (breast cancer) and SK-OV−3, with IC50 values of 105.86 and 72.45 µg/mL and a Selectivity Index of 2.34 and 3.41, respectively. The silver-loaded oil nanoemulsion (Ag-TTO-NE) possessed antioxidant and antimicrobial activities against Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC90274) and Salmonella typhi (ATCC 6539). These results indicate that T. turbinata-based silver nanoemulsions deserve further exploration as multifunctional marine-derived nanoformulations. In silico ADMET analysis projected moderate to high oral absorption for most of the discovered compounds and suggested favorable pharmacokinetic properties of the individual ingredients. ADMET analysis suggested that the major compounds discovered by GC–MS have good medication-like characteristics. These computational predictions are supplemental information and are not to be taken as the pharmacokinetic behavior of the nanoemulsion itself. Overall, the present results are based on in vitro biological assays together with exploratory computational studies and constitute preliminary evidence for the subsequent exploration of this marine-derived nanoformulation. Full article

Pearl millet (Pennisetum glaucum) is a widely cultivated C4 cereal crop in tropical and subtropical regions, serving as a food and feed source in developing countries across Africa and Asia. Despite its agronomic importance, research efforts aimed at developing improved millet varieties under the current climatic changes remain limited, particularly in Africa, including Egypt. This study aimed to establish an efficient regeneration system for the “Shandaweel-1” Egyptian pearl millet variety using immature inflorescences as explants. Six different callus induction media (CIM) treatments were evaluated for their effects on somatic embryogenesis, callus type, vitrification rate, and regeneration efficiency. Among the tested treatments, Murashige and Skoog (MS) media additionally supplemented with 1.0 mg L⁻¹ of l-proline, 1.0 mg L⁻¹ of l-asparagine, 10 mg L⁻¹ of silver nitrate (AgNO₃), 0.32 mg L⁻¹ of copper sulfate (CuSO₄), 1.0 mg L⁻¹ of 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.5 mg L⁻¹ of 6-benzylaminopurine (BAP) produced a high callogenesis rate (93%) and the highest regeneration efficiency (47.6%). The combination of l-proline and l-asparagine enhanced the callus quality and regeneration potential more effectively than casein hydrolysate alone, whereas AgNO₃ addition did not have any significant impact on the vitrification or callogenesis rates. This study represents the first successful establishment of an in vitro regeneration system for an Egyptian pearl millet variety, providing a valuable platform for future genetic modification aimed at enhancing stress resilience and crop productivity. Full article

This work describes an efficient and environmentally friendly method for the synthesis of silver-based nanostructures through a green route using Aloe vera extract as a reducing agent, silver nitrate (AgNO₃) as a precursor, and polyvinylpyrrolidone (PVP, 10 kDa molecular weight) as a stabilizing agent. The formation of these structures was supported by UV–Vis spectroscopy, where a surface plasmon resonance (SPR) band was observed between 425 and 460 nm. Scanning electron microscopy revealed predominantly spherical features in the 300–500 nm range; however, the distinction between primary nanoparticles and aggregates cannot be conclusively established from SEM alone. EDX analysis indicated a silver content of 59.96 wt%. Antibacterial assays performed in Z8 medium demonstrated a reduction in cyanobacterial growth with increasing dosage, with complete inhibition observed at ≥20 $\mu$L (nominal MIC = 1.77 mg mL⁻¹, based on precursor estimation). Total dissolved solids and absorbance measurements exhibited a decreasing trend with increasing concentration (effect size = 0.87, $p<0.001$), supporting an inhibitory effect under the tested conditions. These findings suggest potential antibacterial activity. However, this study should be considered exploratory, and further work is required to elucidate the underlying mechanisms. Full article

The aim of this work was to study the influence of various factors (sucrose concentration, silver nitrate, activated charcoal, and plant growth regulators 2.4-D (2.4-Dichlorophenoxyacetic Acid) and TDZ (Thidiazuron)) on the induction of gynogenesis and their effect on eight genotypes of summer squash on the ploidy level of regenerated summer squash plants (Cucurbita pepo L.) in isolated ovule culture in vitro. IMC (Induction Medium for Cucurbitaceae) nutrient medium supplemented with 2 mg/L 2.4-D or 0.2 mg/L TDZ was used. It was shown that the optimal sucrose concentration for embryogenesis was 30 g/L; at 70 g/L, embryogenesis was absent. The addition of 10 mg/L AgNO₃ in combination with 2.4-D in the genotype Faraon increased the frequency of embryogenesis up to 80%. It was found that a low concentration of activated charcoal (5 mg/L) together with TDZ increased the yield of embryoids by 8.5 times (68% embryogenesis) in the genotype Sangrum. Both growth regulators effectively induce embryogenesis, but their action strongly depends on the genotype and the composition of the nutrient medium. Flow cytometry analysis of 247 regenerant plants adapted to ex vitro conditions of the studied genotypes obtained in this study showed that diploids (2n) accounted for 47.2%, tetraploids (4n) 45.7%, triploids 3.7%, and octoploids 3.4%. Genotype-specificity of growth regulator action was demonstrated: in the genotypes Sangrum and Faraon, TDZ promoted a higher yield of tetraploids, while in the genotype Yakor, 2.4-D was more effective. The obtained tetraploid lines can be used to create seedless triploid hybrids without colchicine treatment. The developed combinations of factors will allow more efficient induction of gynogenesis in summer squash in vitro. Full article