Search Results (736)

Green synthesis is an eco-friendly, simple, and cost-effective process for the synthesis of metal nanoparticles from plant extracts that are rich in bioactive compounds. In the current study, the antioxidant potential and total soluble polyphenol content (TPC) of different parts of Ligusticum mutellina (L.) Crantz were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and the results indicated that the seed extract was the most active plant part. HPLC analysis indicated the presence of phenolic compounds such as gallic acid, protocatechuic acid, and catechin, which may contribute to the reduction and stabilization of AgNPs. Silver nanoparticles (AgNPs) were synthesized from the aqueous seed extract of L. mutellina. The formation of nanoparticles was confirmed by UV–Vis spectroscopy, FT-IR analysis, powder X-ray diffraction (PXRD), and transmission electron microscopy (TEM). The UV–Vis spectrum indicated a surface plasmon resonance peak at around 411 nm, and PXRD analysis indicated an average crystallite size of around 13 nm. TEM analysis revealed predominantly spherical nanoparticles with an average size of 25.36 ± 10.76 nm. The synthesized AgNPs exhibited strong antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Overall, the results demonstrate that L. mutellina seed extract represents an effective natural source of reducing and stabilizing agents for green nanoparticle synthesis and highlight the potential of the obtained AgNPs as environmentally friendly antimicrobial materials. Full article

Two Zn(II) coordination compounds based on glaucine-derived Schiff bases were synthesized and investigated as potential materials for dye-sensitized solar cells (DSSCs). The structures of all compounds were established by X-ray diffraction analysis and quantum chemical modeling (DFT/TD-DFT). Their photophysical properties (absorption and luminescence spectra in solution and the solid state), electrochemical characteristics, and photovoltaic parameters in DSSC devices were studied. The highest power conversion efficiency (PCE ~5.18%) was demonstrated by the free ligands, which is attributed to their favorable absorption spectrum and optimal alignment of energy levels relative to the conduction band of TiO₂ and the redox couple of the electrolyte. The Zn(II) coordination compounds exhibited significantly lower efficiency (~2.1%). Impedance spectroscopy results indicated more efficient charge transfer at the TiO₂/dye/electrolyte interface for the organic derivatives. Full article

Hydrogen plasma heating, a unique method for heating and reducing iron ore, is distinguished by its high heat, rapid reduction, and high efficiency, making it a promising technique in the metallurgy field. In this study, a non-transferred arc plasma heating system was used with Ar-H₂ as the working gas and acidic pellets as the raw material. The microstructures and elemental distributions of the slag and iron phases during the reduction process were examined using electron microscopy and energy-dispersive X-ray. The variation patterns of Fe-containing phases in the reduction products were found using X-ray diffraction and full-spectrum fitting refinement. The conversion rate of the oxidized pellets and the deoxidation conversion rate per area were estimated for various gas flow rates and reduction times. A reaction kinetics model was also used to study the reaction controlling step. The results showed that during the reduction process, with an H₂ flow rate of 4.5 L min⁻¹ and a 40 min reduction, the conversion(α) reached 99.89% and the purity of the reduced metallic iron reached 99.9%, achieving the industrial-grade 3N standard. Si and Al in the melt bath generated fayalite (Fe₂SiO₄) and hercynite (FeAl₂O₄) with Fe_xO. The deoxidation conversion rate per unit area was 1.11 g (cm² min)⁻¹. A three-dimensional diffusion-controlled model was used to describe the reduction process, and the mechanism function was 2/3(1 + α)^3/2[(1 + α)^1/3]⁻¹. The values of the reduction reaction rate constant (K) were 12.6 × 10⁻² s⁻¹ and 12.8 × 10⁻² s⁻¹ when the flow rates of H₂ gas were 3 and 4.5 L min⁻¹, respectively. The apparent activation energy was 21.9 kJ mol⁻¹. The empirical equation for the specific reduction rate was calculated as ln r = −2637.5/T − 0.407. Full article

A novel catalyst, Tm₂FeSbO₇, was synthesized by employing the solid-phase high-temperature sintering method, and, for the first time, it was utilized to create a Z-type heterojunction with BiYO₃. A direct Z-scheme Tm₂FeSbO₇/BiYO₃ heterojunction photocatalyst (TBHP) was successfully produced by employing the ball-milling technique. X-ray diffraction analysis results indicated that Tm₂FeSbO₇ crystallized in a cubic pyrochlorestructure which owned the Fd-3m space group, with a unit cell parameter of 10.1769 Å, whereas BiYO₃ displayed a fluorite structure in the Fm-3m space group, with a unit cell parameter of 5.4222 Å. The Mossbauer spectrum of Tm₂FeSbO₇ showed that Fe³⁺ ions might locate at octahedral sites. The measured bandgap widths for the TBHP, Tm₂FeSbO_7, and BiYO₃ were 2.14 eV, 2.21 eV, and 2.30 eV, respectively. Multiple experimental results demonstrated that the TBHP exhibited a higher valence band ionization potential, a narrower band gap width, and a higher removal efficiency of the sulfamethoxazole (SMX) compared with the Dy₂TmSbO₇/BiHoO₃ heterojunction photocatalyst. Under visible-light irradiation (VISLI) of 115 min, the TBHP showcased exceptional photocatalytic elimination performance; therefore, the elimination rate of the SMX and the total organic carbon (TOC) mineralization rate reached 99.51% and 98.10%, respectively. In contrast to single-component Tm₂FeSbO₇, BiYO_3, or conventional nitrogen-doped titanium dioxide (N-TiO₂) catalyst, the TBHP exhibited removal efficiency enhancement for degrading the SMX by 1.17 times, 1.31 times, or 4.06 times. Simultaneously, the matching mineralization rate for removing the TOC density by employing the TBHP was 1.20 times, 1.34 times, or 4.73 times higher than that by employing Tm₂FeSbO₇, BiYO₃, or conventional N-TiO₂. Above experimental results indicated that the mineralization efficiency for removing TOC density by employing the TBHP was higher than that by employing Tm₂FeSbO₇, BiYO₃, or N-TiO₂. Radicals trapping experiments and the electron paramagnetic resonance spectroscopy results revealed that hydroxyl radicals, superoxide anions, and photoinduced holes were the primary active species during the catalytic elimination course of the SMX by employing the TBHP under VISLI. The results demonstrated that the direct Z-scheme TBHP, which was developed in this study, exhibited the maximal removal efficiency for degrading the SMX in contrast to Tm₂FeSbO₇, BiYO₃, or N-TiO₂. Additionally, the possible elimination routes and elimination mechanisms of the SMX were proposed. Therefore, an important scientific foundation for developing high-performance heterojunction catalysts was established. Full article

Derivatives of 4,7-diphenyl-2,1,3-benzothiadiazole are highly stable compounds that fluoresce efficiently both in solutions and in the crystalline state. Thanks to their wide range of remarkable optoelectronic characteristics, they can rightly be called smart materials. This paper presents the results of an investigation into the polymorphism of 4,7-bis(4-(trimethylsilyl)phenyl)-2,1,3-benzothiadiazole (TMS-P-BTD) crystals under weakly and strongly non-equilibrium crystallization conditions from the vapor phase (PVD), solutions, and melt. Using single-crystal X-ray diffraction analysis at room temperature, two new polymorphic crystal modifications have been identified: orthorhombic II (sp. gr. Pnaa, Z/Z′ = 12/1.5) and triclinic III (sp. gr. P-1, Z/Z′ = 8/4). It was determined that the densest polymorph III melts at 154 °C. The least dense orthorhombic polymorph II dominates under kinetic growth conditions, melts independently at 151 °C, but transforms into polymorph III upon prolonged annealing. It has been established that the previously identified monoclinic polymorph I (P2₁/c, Z/Z′ = 32/8) transforms into polymorph III upon heating in the range of 75–110 °C. In the series of polymorphs I→II→III, a blue shift in the fluorescence spectrum maximum is observed: approximately 375 cm⁻¹ for polymorph II and ~635 cm⁻¹ for polymorph III relative to the position of the maximum λ_max,I = 497 nm for polymorph I. The observed spectral-fluorescence features of the TMS-P-BTD crystal polymorphic phases are consistent with the structure of the flattest molecular conformers within the crystal unit cells. Full article

Post-harvest deterioration in strawberries is an urgent and critical issue that requires significant attention. Glycerol monolaurate (GML), a broad-spectrum food-grade antimicrobial agent, faces limited applicability due to its poor water solubility. In this study, a confined encapsulation strategy was employed to encapsulate GML within hydroxypropyl-γ-cyclodextrin (HPγCD), which improved the physicochemical properties of GML and enhanced its stability in the environment. The fiber morphology was observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the presence of a uniform, non-nodular core–shell structure. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) validated the successful encapsulation of GML within the cavity of HPγCD. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of the core–shell system was significantly improved. In vitro release followed first-order kinetics (R² = 0.9842), with 79.5% of GML released over 68 h. The DPPH and ABTS assays demonstrated that PLA/GML-HPγCD NF exhibited sustained radical scavenging activity (p < 0.05, ANOVA). Compared to GML-HPγCD NF, PLA/GML-HPγCD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HPγCD NF significantly reduced lesion diameter and weight loss while maintaining hardness, total soluble solids, and vitamin C content over 8 days of storage. In conclusion, these characteristics highlighted the potential of P/G-HPγCD NF as a promising active packaging material for extending the shelf life of perishable fruits. Full article

The construction of Z-scheme heterojunctions is regarded as one of the most effective modification strategies for photocatalysts. However, how to improve the interfacial charge transfer efficiency to further enhance the photocatalytic activity remains an urgent issue to be addressed. In this study, sulfur vacancy-enriched ZnIn₂S₄/MoS₂ Z-scheme heterojunctions (V-ZIS/MS) containing interfacial Mo-S bonds was successfully synthesized using a hydrothermal method. The V-ZIS/2%MS showed the highest hydrogen evolution rate, achieving 19.21 ± 0.78 mmol·g⁻¹·h⁻¹ under visible light and 112.89 ± 10.98 mmol·g⁻¹·h⁻¹ under full-spectrum illumination, which are 5.07 and 4.41 times higher than ZIS (3.79 ± 0.79 mmol·g⁻¹·h⁻¹) and V-ZIS (4.36 ± 0.98 mmol·g⁻¹·h⁻¹) under visible light, respectively, outperforming most reported ZIS-based photocatalysts. This is because the composite of V-ZIS and MS enhanced its light absorption performance. More importantly, the formation of Mo-S bonds at the V-ZIS/MoS₂ interface facilitated efficient charge transfer and reduced interfacial resistance, leading to significantly improved photocatalytic activity. Cycling experiments further demonstrate that V-ZIS/2%MS exhibits considerable photocatalytic stability. X-ray diffraction analysis before and after the reaction further confirmed the structural stability of the catalyst. This work provides a certain reference for the preparation of high-performance ZIS-based photocatalysts. Full article

Michael acceptors, such as chalcones and benzylidenes, are privileged scaffolds for the development of anticancer agents. Taking this into account, we developed a selective Claisen–Schmidt condensation of the dammarane-type triterpenoid hollongdione with pyridine-2-carbaldehyde, enabling controlled synthesis of mono- and bis-substituted triterpenes depending on the reaction conditions. The reaction demonstrated high temperature-dependent regioselectivity, providing C2-mono- 2 or 2,21-bis-substituted 3 triterpenes with yields up to 96% and 95%, respectively. The structures of the newly synthesized triterpene chalcones were elucidated by 1D and 2D NMR spectroscopy and unambiguously confirmed by a single-crystal X-ray diffraction, which established the E configuration of the exocyclic double bond. In biological studies, the bis-2-pyridylidene derivative 3 exhibited a pronounced and broad-spectrum antitumor activity in the NCI-60 panel, inducing cell death in 58 of 59 cancer cell lines. High selectivity toward melanoma, renal, and prostate cancer cell lines was observed, with selectivity indices (SI) of up to 18.82 for melanoma LOX IMVI. In MTT assays, compound 3 displayed a submicromolar cytotoxicity, particularly against the KRAS-mutant PANC-1 cell line (IC₅₀ = 0.22 µM). Anticancer activity was further confirmed in a zebrafish (Danio rerio) xenograft model of human HCT116 colon cancer, where tumor growth inhibition reached 72% without pronounced embryotoxicity (LC₅₀ = 1.4 µM). We have developed an efficient approach for the site-selective modification of hollongdione, providing access to potent anticancer dammarane-type chalcones. The bis-2-pyridylidene derivative 3 emerged as a promising lead compound, demonstrating submicromolar potency, high selectivity towards melanoma, and significant in vivo efficacy in a zebrafish xenograft model. Full article

This review aims to explore the green synthesis of metal and metal oxide nanoparticles using various species of the genus Artemisia. The synthesis processes commonly involve aqueous or organic extracts of plant parts (e.g., leaves, stems, and roots), which react with metal salt solutions (e.g., AgNO₃, Zn(NO₃)₂, HAuCl₄, Cu(NO₃)₂) under controlled parameters, including pH, temperature, and light exposure. The synthesized nanoparticles are characterized using techniques such as UV–Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), and zeta potential analysis. These approaches provide information on nanoparticle size, morphology, crystallinity, surface chemistry and charge, which are significantly influenced by synthesis parameters and the specific Artemisia species used. The biosynthesized nanoparticles have demonstrated promising multifunctional applications, including broad-spectrum antimicrobial activity against bacterial and fungal strains, antioxidant capacity, anticancer potential, as well as applications in agriculture and environmental remediation. Full article

This study evaluates the swelling potential in clayey soils of the Paleogene Brebi, Mera, and Moigrad formations in the Transylvanian Basin (Romania) by integrating direct free-swelling tests (FS; STAS 1913/12-88) with indirect index-property diagrams and semi-quantitative X-ray diffraction (XRD; RIR method). The indirect analysis combines three swelling-susceptibility classification charts—Seed et al. (AI–clay), Van der Merwe (PI–clay), and Dakshanamurthy and Raman (LL–PI)—with mineralogical trends from the Casagrande plasticity chart, complemented by Holtz and Kovacs’s clay-mineral reference fields and Skempton’s activity concept (AI = PI/% < 2 µm). The geotechnical dataset comprises 88 Brebi, 46 Mera, and 263 Moigrad specimens (with parameter counts varying by test), an XRD was performed on a representative subset. The free swell (FS) results indicate that Brebi soils range from low to active behavior (50–135%) without reaching the very active class; most Brebi specimens fall in the medium-activity range. Moigrad spans the full FS spectrum (20–190%) but is predominantly in the medium-to-active range. In contrast, Mera soils exhibit predominantly active behavior, covering the full range of activity classes (30–170%). The empirical classification charts diverge systematically: clay-sensitive schemes tend to assign higher swell susceptibility than the LL–PI approach, especially in carbonate-influenced soils. XRD results corroborate these patterns: Brebi is calcite-rich (mean ≈ 53.5 wt% CaCO₃) with minor expandable minerals (mean ≈ 3.1 wt%); Mera is feldspathic (orthoclase mean ≈ 55.3 wt%) with variable expandable phases; and Moigrad has a higher clay-mineral content (mean ≈ 38.8 wt%). Overall, swelling is controlled by the combined effects of clay-fraction reactivity, clay volume continuity, and carbonate-related microstructural constraints. Full article

In the present study, potato starch (PS) was functionalized with theaflavin (TF). Potato starch aldehyde (DPS)–theaflavin (DPS-TF) conjugates were prepared by conjugating TF with DPS. The synthesized DPS-TF conjugates were characterized via UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), proton nuclear magnetic resonance (¹H-NMR) and scanning electron microscopy (SEM) analysis and tested for antioxidant and antimicrobial activities. The UV–vis spectrum results demonstrated that DPS-TF conjugates exhibited the characteristic absorption peaks of theaflavin at 280 nm, which can be attributed to the benzotropolone structure present in theaflavin. The absorbance values of the peaks progressively intensified as the concentration of grafted theaflavins increased. FTIR confirmed the depletion of the aldehyde groups and the presence of TF-specific vibrations in the conjugates in DPS-TF. ¹H-NMR demonstrated that the conjugation occurred between the H-6, H-8, H-6′, and H-8′ positions of theaflavin and the aldehyde groups of starch aldehyde. XRD demonstrated that the DPS-TF conjugates were in the amorphous state. SEM observation demonstrated that DPS-TF exhibited a mixed morphology of flakes and lumps, which differed from that of native starch and starch aldehyde. The scavenging activity of DPS-TF against DPPH and ABTS radicals was significantly higher than that of DPS (p < 0.05), with the antioxidant activity increasing in line with the concentration of theaflavins. In comparison with PS and DPS, DPS-TF conjugates demonstrated superior antimicrobial activity against Escherichia coli and Staphylococcus aureus. Furthermore, an elevated grafting ratio corresponds to a heightened level of these functional properties. This study highlights the promise of the starch aldehyde–theaflavin conjugates for use as a viable antioxidant and antimicrobial agent for food applications. Full article

This study reports the sustainable synthesis and thermal, morphological, and structural characterization of multifunctional silver/hydroxyapatite nanocomposite prepared from recycled caprine bone. The organic extract from caprine bone was characterized using Fourier Transform Infrared (FTIR) and Ultraviolet–Visible Spectroscopy (UV-Vis). The biogenic hydroxyapatite (CHAP) and its silver composite (Ag@CHAP) were characterized using thermal gravimetric analysis (TGA), Raman spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscope (TEM). The photocatalytic activity of Ag@CHAP was quantitatively confirmed through the degradation of Crystal Violet (5 ppm) under sunlight, achieving a high removal efficiency of 99.8% under optimum conditions, demonstrating significant potential for wastewater remediation. Ag@CHAP also demonstrated enhanced antimicrobial activity compared with CHAP and showed broad-spectrum efficacy against clinical human isolates P. aeruginosa ATCC 10145, E. coli ATCC 35218, S. aureus ATCC 25923, and C. albicans (human isolate). The in vitro hemolytic-activity assays revealed that both CHAP and Ag@CHAP had no hemolytic activity after 24 h of red blood cells incubation and effectively reduced lead-induced hemolysis from 86.73% to 39.35% and 49.13%, respectively. These findings confirm CHAP and Ag@CHAP as stable, biocompatible, and high-performance materials with promising applications in the sustainable water-treatment and biomedical fields. Full article

This study evaluated the thermal properties, crystallinity, particle size, morphology, and in vivo local inflammation and persistence of two poly-L-lactic acid (PLLA) injectable implants, Sculptra^® (PLLA-SCA) and GANA V^® (PLLA-GA). PLLA-SCA and PLLA-GA underwent differential scanning calorimetry and X-ray powder diffraction to evaluate their thermal properties and degree of crystallinity. X-ray powder diffraction spectra displayed a sharper, more intense peak for PLLA-GA than PLLA-SCA, with smaller peaks on either side of the main peak of PLLA-GA but not PLLA-SCA. Differential scanning calorimetry thermograms indicated three thermal events for both PLLA-SCA and PLLA-GA. For PLLA-SCA, the first two events occurred between 65 °C and 90 °C, and the third event occurred at 165 °C. For PLLA-GA all three events occurred between 156 °C and 169 °C. Heating samples to 120 °C and cooling to room temperature prior to differential scanning calorimetry resulted in no thermal events being observed between 65–90 °C with either product, while three events were observed with PLLA-GA and one event with PLLA-SCA between 156 °C and 169 °C. The median volume distribution diameter was 46.4 µm for PLLA-SCA and 31.7 µm for PLLA-GA. Scanning electron microscopy showed PLLA-GA particles were irregular in shape, had no sharp edges and had a wrinkled and crimped surface, while PLLA-SCA particles displayed plate-like shapes and had smoother surfaces. In vivo inflammatory reactivity scores indicated a slight reaction for PLLA-SCA at all time points (3.7 ± 1.1, 6.1 ± 1.6, 5.7 ± 1.2 and 6.2 ± 1.2 at 2, 12, 26 and 52 weeks, respectively), while for PLLA-GA, a moderate reaction was observed at 12 and 26 weeks (2.9 ± 1.5, 10.1 ± 1.0, 9.4 ± 0.7 and 7.1 ± 1.3 at 2, 12, 26 and 52 weeks, respectively). PLLA-SCA and PLLA-GA had similar persistence scores at 2, 12 and 26 weeks, while at 52 weeks the score was markedly higher for PLLA-SCA versus PLLA-GA (1.9 ± 0.2 versus 0.7 ± 0.2). In conclusion, PLLA-SCA is more amorphous than PLLA-GA. The single melting point of PLLA-SCA contrasts with the broader spectrum of melting points for PLLA-GA suggests a more homogenous formulation of PLLA-SCA. This, and its less crystalline structure, result in the slower degradation rate and more sustained biological response of PLLA-SCA compared with PLLA-GA. The physiochemical properties of PLLAs affect the biological response in clinical practice and should be taken into consideration when selecting a PLLA treatment for aesthetic use. Full article

A promising direction for the creation of new biologically active derivatives of the alkaloid lupinine is the synthesis of “hybrid molecules” that combine a fragment of the alkaloid and the pharmacophore of 1,2,3-triazole in their structure. From a biological perspective, this work presents the first X-ray diffraction study of a single crystal of (1S,9aR)-1-({4-[4-(Benzyloxy)-3-methoxyphenyl]-1H-1,2,3-triazol-1-yl}methyl)octahydro-2H-quinolizine, a new, recently synthesized 1,2,3-triazole derivative of lupinine. A comparison of theoretically predicted and experimentally observed structural parameters was carried out. The FTIR spectroscopy study and vibrational properties calculations allowed us to interpret the FTIR absorption spectrum and localize specific vibrational modes in quinolizidine, 1,2,3-triazole, and benzene rings. Such information can be fruitful for further characterization of the synthesis process and products. The molecular docking of the compound was performed. It was shown that the studied molecules are capable of interacting with the Mpro binding site via non-covalent and hydrophobic interactions with subsites S3 (Met165, Glu166, Leu167, Pro168) and S5 (Gln189, Thr190, Gln192), which ensure the stabilization of the Mpro substrate. Blocking of the active site of the enzyme in the region of the oxyanion hole does not occur, but stable stacking interactions with the π-system of one of the catalytic amino acids, His41, are observed. Full article

A review of studies has shown that aromatic azo and hydrazo derivatives are used in a wide spectrum of fields, including food, pharmaceutical, and cosmetic products, as well as in technical and electronic technologies, which has contributed to the development of new such compounds. In this work, the structures of newly obtained 4-methyl-3,5-dinitro-2-(2-phenylhydrazinyl)pyridine (4MDNPHP) and its azo derivative, 4-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine (4MDNPAP), were established by spectroscopic (NMR, IR, Raman, and UV-Vis) and emission studies. Single-crystal X-ray diffraction analysis was used to determine the molecular structure of the studied compounds, and the results were compared with DFT calculations (B3LYP/6-311G(2d,2p)). The collected X-ray data revealed that the crystal of the hydrazo compound (4MDNPHP) belongs to the triclinic space group P$\overline{1}$ (Z = 2), whereas the crystal of the azo compound (4MDNPAP) follows the symmetry of the monoclinic space group P2₁/n (Z = 4). Both presented derivatives crystallized with one molecule in the asymmetric unit. Specific properties of the hydrazo bridge C_ϕ-NH-NH-C_θ moiety and its azo counterpart C_ϕ-N=N-C_θ were considered in detail. Full article