Transmission Electron Microscopy Images Research Articles

Hierarchical core-shell ZIF-11@ZIF-8 composite nanocatalyst for high-yield simultaneous transesterification-esterifications of sunflower oil to produce biodiesel

Decreasing the mass transfer resistance is a promising technique to prepare an efficient catalyst for improving biomass macromolecules conversion in biodiesel production. In this study, hierarchical core–shell composite nanocatalysts were prepared through a solvothermal technique using zeolitic imidazolate framework-8 (ZIF-8) and ZIF-11 metal–organic frameworks (MOFs). The nanocatalysts were characterized by XRD, FT-IR, BET, FE-SEM, EDS, XPS, TEM, NH3-TPD, and CO2-TPD analyses. The results showed high crystallinity, high surface area (1446.86 m2/g), high pore volume (0.65 cm3 g−1), and mesoscale pore size (2.37 nm). Furthermore, TEM images confirmed the formation of core–shell structure for the composites. The catalytic activity was evaluated in the transesterification of sunflower oil at different operating conditions. The highest biodiesel yield (96.4 %) and full free fatty acid (FFA) conversion were obtained over the ZIF-11@ZIF-8 nanocatalyst at the optimum operating conditions: 120 °C, catalyst concentration of 8 wt%, methanol to oil ratio of 40:1, and 10 h. The ZIF-11@ZIF-8 nanocatalyst showed high thermal and chemical stability after several sequence cycles, leading to high reusability.

Sustainable supercapacitors of sulfur-doped carbon from environmentally friendly sodium lignosulfonate impregnated with bacterial cellulose

The use of sustainable natural sources to fabricate porous carbon materials has garnered significant interest in energy storage. This study proposes a method for synthesizing sulfur-doped porous carbon (S‑carbon) materials via the carbonization of bacterial cellulose (BC) impregnated with sodium lignosulfonate (LS), which functions as a renewable source of both carbon and sulfur, eliminating the need for external activation processes. The carbonization process yielded S‑carbon with a notable sulfur content of 1.4 % and a high specific surface area of 650 m2/g. Transmission electron microscopy (TEM) images reveal fibrous carbon structures with mesopores and micropores in the S‑carbon material. Electrochemically, S‑carbon exhibited an impressive specific capacitance of 272.6 F g−1 at a current density of 1 A/g and demonstrated outstanding cycling stability, retaining 86 % of its capacitance after 5000 cycles at a current density of 6 A/g in a 3 M KOH electrolyte. The development of sulfur-doped fibrous carbon from BC-LS offers promising potential as a sustainable electrode material for supercapacitors.

Nanostructured spinel ferrites: A comprehensive study on the synthesis, characterization, and magnetic properties of Zn and Mn substituted magnetite nanoparticles produced through the co-precipitation method

Seven cubic spinel ferrite nanoparticles were successfully synthesized through the co-precipitation method. These nanoparticles include Fe3O4, Zn0.4Fe0.62+Fe23+O4, Mn0.4Fe0.62+Fe23+O4, Zn0.6Mn0.4Fe0.42+Fe1.63+O4, Zn0.4Mn0.6Fe0.42+Fe1.63+O4, Zn0.4Mn0.4Fe0.22+Fe23+O4, and Zn0.4Mn0.4Fe0.42+Fe1.83+O4. The Rietveld method was used to analyze X-ray diffraction data, confirming that all samples have a single-phase cubic spinel structure. The presence of zinc and manganese ions in magnetite lattice leads to changes in lattice parameters and crystallite size, resulting in a range of 7–12 nm crystallite sizes. Fourier transform infrared spectroscopy (FT-IR) analysis of nanoparticles reveals two significant adsorption peaks at 560-576 cm−1 and 437-449 cm−1, corresponding to metal ion stretching vibrations at tetrahedral and octahedral sites. The X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of iron, zinc, and manganese in various oxidation states. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images showed spherical, agglomerated nanoparticles. The study confirmed the elemental composition and mapping images of prepared samples using energy-dispersive X-ray spectroscopy (EDS). The magnetic properties of the synthesized nanoparticles were meticulously examined utilizing a vibrating sample magnetometer (VSM) at room temperature. A direct correlation is established between the structural alterations induced by Zn2+/Mn2+ and their subsequent effects on magnetic characteristics, specifically through the reallocation of cations and the mechanisms of electron hopping occurring at the B-sites. The structural modifications result in enhanced superparamagnetic behavior, exhibiting saturation magnetization values between 46.01 and 69.38 emu/g. The sustainable characteristics of these materials render them highly viable options for applications in environmental remediation and green technology.

A Review on the Partitioning of Solutes Along Dislocations and Stacking Faults in Superalloys

AbstractChemical and microstructural alterations at near-atomic scale can influence the high temperature mechanical performance of superalloys. These alterations are strongly associated with solute segregation at crystal defects, such as dislocations and stacking faults. This review provides an overview of the phenomena that occurs during deformation at elevated temperatures due to the interactions of solutes with crystal defects. These interactions are discussed based on investigations conducted by exploiting the recent technological advancements of advanced characterization methods, such as transmission electron microscopy and atom probe tomography. Insights on local phase transformation mechanisms along stacking faults are discussed providing perspectives on new alloy design concepts. Besides, various microstructural alterations controlled by the interactions of solutes with dislocations are discussed. Bringing together observations at near-atomic scale that control superalloys in the macroscopic level, we aim to bridge an atomic scale microanalysis gap. Thus, providing insights that future alloy designers, modelers, and engineers can incorporate these effects into their analyses, alloy design models and life prediction calculations.

Dysprosium chromite nanoparticles: A promising photocatalyst for the remediation of ciprofloxacin and methylene blue from wastewater

A facile sol-gel synthesis method was employed to synthesize dysprosium chromite (DyCrO3) nanoparticles (NPs), which were subsequently calcined at 750 ∘C to investigate their structural, optical, and photocatalytic properties. Rietveld refinement of powder X-ray diffraction patterns revealed a single-phase orthorhombic structure for the DyCrO3 NPs, exhibiting good crystallinity and belonging to the Pbnm space group. Furthermore, Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy imaging revealed a promising morphology with an average particle size of 30 ± 7 nm. Optical assessments indicated an energy band gap of 2.72 eV, suggesting potential for solar light harvesting as a photocatalyst. Mott-Schottky plots confirmed the n-type semiconductor behavior of the DyCrO3 NPs, and valence band X-ray photoelectron spectroscopy analysis supported these findings. Electronic band structure calculations showed a substantial conduction band minimum and a positive valence band maximum, essential for promoting oxygen reduction and oxidation reactions, respectively, which are crucial for photocatalytic activity. Moreover, the synthesized DyCrO3 NPs demonstrated significant potential as efficient photocatalysts, effectively decomposing the antibiotic ciprofloxacin (CIP) under solar light. Notably, the DyCrO3 NPs achieved 83 % degradation of CIP within 240 min of solar irradiation. Similarly, under identical conditions, the DyCrO3 NPs photocatalyst showed promise in degrading 70 % of the colored organic pollutant methylene blue (MB). Interestingly, during the first 120 min, the degradation of CIP was approximately 25 % greater than that of MB. The ability of DyCrO3 NPs to efficiently degrade both colored and colorless pollutants highlights the catalyst’s inherent photocatalytic nature, rather than merely relying on dye-sensitization effects. Furthermore, the presence of DyCrO3 NPs reduced the activation energy for CIP degradation from 31.657 kJ mol−1 K−1 to 20.846 kJ mol−1 K−1, providing additional evidence of their true catalytic efficacy. Apparent quantum yield values of 40 % for CIP and 35 % for MB degradation further illustrate their superior solar energy harvesting ability. A comprehensive mechanism was developed to explain the impressive photocatalytic performance of the synthesized NPs, highlighting their potential in degrading pharmaceutical antibiotics.

Transglutaminase from Asian seabass liver: purification, characterization and cross-linking activity against natural actomyosin

The study investigated the purification and characterization of transglutaminase (TGase) from Asian seabass liver. In addition, protein cross-linking ability of partially purified TGase was also elucidated against the natural actomyosin extracted from threadfin bream surimi. During ammonium sulfate fractionation, the highest specific activity (11.31 ± 0.17 units/mg protein) was obtained from the 80–100% ammonium sulfate (AS) fraction (partially purified TGase; pTGase). Purity increased 1.46 times compared to crude samples with a 73% yield. Further purification using DEAE-Sepharose enhanced the specific activity (904.71 ± 4.65units/mg protein) by 117.19-fold as compared to the crude sample. The molecular weight (MW) of the purified TGase was 43.4 kDa, which was slightly different than the MW determined by SDS-PAGE (41.1 kDa). Optimal TGase activity was found at 45–50 °C and pH 8, with significant declines beyond these ranges. Furthermore, TGase maintained activity (80%) when heated till 55 °C, whereas it showed wide-range pH stability. NaCl and CaCl2 at 3% and 20 mM, respectively enhanced TGase activity. When natural actomyosin (NAM) was treated with pTGase at various concentrations (1–10 unit/mg protein), decreasing solubility and ɛ-amino groups confirmed its cross-linking ability. The result was also supported by the formation of aggregates of NAM proteins as determined by transmission electron microscopic images. Thus, Asian seabass liver could be a new source of purified and partially purified TGase, which can be employed for various food and pharmaceutical applications.

Green synthesis of silver nanoparticles containing Cichorium intybus to treat the sepsis-induced DNA damage in the liver of Wistar albino rats

Abstract Sepsis is a severe reaction of the body to an infection, presenting a critical medical crisis. It represents an imbalance between the body’s anti- and pro-inflammatory reactions. The occurrence of sepsis, which leads to multiple-organ failure and increased mortality, is marked by dysfunction in the lungs, heart, kidneys, and liver. The involvement of reactive oxygen species is believed to contribute to the progression of sepsis. Data suggest potential advantages of phenolic compounds derived from plants in combating sepsis. Plant polyphenols can be antioxidants by scavenging free radicals, chelating metals, and binding to proteins. In this research, silver nanoparticles (AgNPs) were produced by the aqueous extract of Cichorium intybus leaf for the purpose of treating sepsis-induced DNA harm. The recent study focused on the biological aspect including the cytotoxicity properties on normal (HUVEC) cell line. The AgNPs were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier-transform infrared spectroscopy, X-ray powder diffraction, and UV-Vis. The TEM and SEM images of AgNPs exhibited the average size of 35.29 nm with spherical morphology. In the in vivo study, the animals were categorized into four groups: sepsis-induced, sham, AgNPs-20, and AgNPs-100. AgNPs treatment resulted in a significant decrease in tissues damage (p < 0.01). The sepsis-induced group showed a significantly elevated malondialdehyde (MDA) level in comparison to the sham group (p < 0.01). Nevertheless, the groups that received AgNPs experienced a decrease in MDA levels and an increase in glutathione and superoxide dismutases levels (p < 0.01). Additionally, the rats treated with AgNPs exhibited a reduction in the IL-1β mRNA expression levels (p < 0.01).

Accurate quantification of dislocation loops in complex functional alloys enabled by deep learning image analysis

In-depth statistics of individual defects observed during transmission electron microscopy (TEM) experiments are essential for the thorough characterization of materials. In this study, we aim to quantitatively characterize the population of dislocation loops in ion-irradiated CrFeMnNi alloys. To this end, we propose an efficient guideline to prepare TEM micrographs dataset for deep learning analysis, adapted for accurate characterization of microstructures produced by thousands of overlapping defects, a very common situation in TEM images, unfeasible by previous existing methods. To reduce human effort, we annotate only a few images and complement the database through a two-step process: initially, singular value decomposition to normalize image background, followed by a controlled data augmentation. The performed analysis provides precise quantitative information about the number of loops of different types, as well as their spatial distribution, their size, and the inter-object distances. These characteristics provide insights into the nucleation, mobility, and growth of dislocation loops, as well as the elastic anisotropy of the material. Our results emphasize how accurate analysis of complex microstructures can provide insights into the physical properties of materials and open up many perspectives for attaining quantitative information on materials properties based solely on their image analysis.

First report of cucurbit yellow stunting disorder virus causing yellowing disease on major gourds in India

Cucurbitaceous crops are a key group of vegetables widely cultivated in India. Characterized yellowing symptoms along with interveinal chlorosis, mottling and downward curling were observed in ridge gourd, snake gourd, and bottle gourd along with the presence of whiteflies (Bemisia tabaci). To investigate the infecting virus, RT-PCR assays followed by sequencing and Transmission Electron Microscopy (TEM) analysis were performed. Sanger sequencing, nucleotide sequence analysis, and TEM imaging confirmed the association of cucurbit yellow stunting disorder virus (CYSDV), genus Crinivirus within the family Closteroviridae. This study reports the natural occurrence of CYSDV in ridge gourd, snake gourd, and bottle gourd for the first time in India.

Optical and structural properties of Er3+-doped CsPbI3 nanocrystals embedded in borosilicate glass

This study investigated the optical and structural properties of the Er3+-doped CsPbI3 nanocrystals (CsPbI3:x%Er) embedded into a borosilicate glass matrix. All these inorganic perovskite NCs were synthesized via the fusion method with a subsequent annealing temperature of 500 °C at different times to control NCs size. Transmission Electron Microscopy images showed nanocrystals within the glass matrix with an interplanar distance of d015 = 0.29 nm and an average size ranging from 3.85 to 6.24 nm. The X-ray diffraction data revealed that the CsPbI3:x%Er NCs can present themselves in cubic, tetragonal, or orthorhombic phases depending on the Er-doping concentration. The photoluminescence spectra of the samples annealed for 1–6 h evidence the structural transformation of CsPbI3 NCs from orthorhombic to cubic crystalline structures. The overlap observed between the optical absorption and photoluminescence spectra provided compelling evidence of an energy transfer process among CsPbI3 NCs phases and the electronic state of the Er3+ ions and the time-resolved photoluminescence monitored at 698 nm revealed the existence of distinct emitting levels due to the coexistence of different CsPbI3 NC crystalline structures. The sample doped with 2 % Er3+ and annealed at 500 °C for 6 h demonstrated improvement in the PL emission of the cubic-CsPbI3 NCs, making it suitable for optical applications.

Base-free aqueous Suzuki–Miyaura coupling reaction using recoverable bi-functional Pd supported nanocatalyst

A solid base catalyst comprising pyridine-palladium polyorganosiloxane framework was synthesized via a grafting method. The resulting organic–inorganic hybrid palladium nanomaterial was characterized by 13C CP-MAS NMR, 29Si CP-MAS NMR, XRD, EDX, TEM, TGA, and the BET measurements. The hybrid palladium nanomaterial exhibited high catalytic activity for the Suzuki–Miyaura cross-coupling reaction between aryl chlorides and phenylboronic acid under base-free and aerobic conditions. A maximum turnover number (TON) of 3150, with a 0.2 mol% Pd loading and a reaction temperature of 80 °C in aqueous solution. The catalyst demonstrated remarkable stability, maintaining its activity even after six cycles of reuse without significant loss of activity. TEM images showed that the catalyst retained its structure and high-order mesostructure after several uses. ICP-AES also confirmed the absence of palladium contamination in the final products. Leaching test studies further confirmed the true heterogeneous nature of the developed catalytic system.

Exploring the photocatalytic breakdown of organic pollutants using intercalated ZnO/SiO2 nanocomposites

The increasing prevalence of organic pollutants in water sources necessitates the development of efficient and cost-effective photocatalysts for their degradation. ZnO nanoparticles (NPs) have been widely studied for their photocatalytic properties; however, their application is hindered by low photocatalytic efficiency and high recombination rates of photogenerated carriers. This manuscript explores the enhanced photocatalytic performance of intercalated ZnO/SiO2 nanocomposites (NCs), synthesized through a combination of co-precipitation and Stöber methods, as a solution to these challenges. A comprehensive analysis of the structural, optical elemental and Morphological properties of both ZnO NPs and ZnO/SiO2 NCs was conducted using various characterization techniques, including X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–Vis spectrometry and Brunauer-Emmett-Teller (BET) analysis. Through, XRD analysis, the calculated crystallite sizes of ZnO NPs and ZnO/SiO₂ NCs were found to be 36 nm and 39 nm respectively. TEM images illustrated that the ZnO NPs and ZnO/SiO₂ NCs have crystallized in elongated spherical morphology. XPS and FTIR analyses provided the signature band details the presence of Cu and Si in their Zn2⁺ and Si⁴⁺ oxidation states. The optical bandgap energies were calculated to be 3.38 eV for ZnO NPs and 3.22 eV for ZnO/SiO₂ NCs. The enhanced photocatalytic efficiency of the ZnO/SiO2 NCs achieved an impressive degradation rate of 92 % for Rhodamine B (RhB), compared to a relatively lower rate of 81 % for pure ZnO NPs for the degradation of RhB under visible light due to its lower bandgap, high surface area, and lower electron-hole recombination rate. BET surface area measurements revealed that ZnO nanoparticles have a surface area of 11.234 m2/g, while ZnO/SiO₂ NCs show 57.118 m2/g, highlighting SiO₂'s enhancement. The NCs demonstrated exceptional reusability for degradation, sustaining high efficiency across multiple cycles. Its ability to scavenge superoxide radicals highlighted the effectiveness of the ZnO/SiO₂ NCs in environmental remediation, especially for wastewater treatment.

Oxidative stress, histopathological and genotoxicity of copper oxide nanoparticles in Biomphalaria alexandrina snail

AbstractHigher usage of copper oxide nanomaterials in industrial and biomedical fields may cause an increase of these nanoparticles in aquatic environments, which could have a detrimental ecological effect. Thus, the objective of this study was to evaluate the acute toxicity of copper oxide nanoparticles on the freshwater gastropod, Biomphalaria alexandrina. Transmission electron microscopy, x-ray diffraction analysis and UV–VIS spectrophotometer of CuO NPs revealed a typical TEM image and a single crystal structure with average crystallite size of approximately 40 nm also, a sharp absorption band was appeared. Following exposure to sub-lethal concentrations of CuO NPs (LC10, 15.6 mg/l and LC25, 27.2 mg/l), treated snails revealed a significant decrease (p < 0.05) in total antioxidant capacity, reduced glutathione contents as well as catalase, and sodium dismutase activities were significantly declined (p < 0.05) in comparison to the control group. Also, histopathological alterations were observed in the digestive gland, including ruptured and vacuolated digestive cells, and a marked increase in the number of secretory cells and the severity of the damage increased with rising concentrations. Furthermore, changes in RAPD profiles were detected in the treated snails. In conclusion, our research highlights the potential ecological impact of CuO NPs release in aquatic ecosystems and advocates for improved monitoring and regulation of CuO NPs industrial usage and disposal.

Structural evolution and magnetic, optical, and optoelectronic properties changes in annealed Co0.5Sr0.5Fe2O4 nanoparticles: A comprehensive study

A sample of Co0.5Sr0.5Fe2O4 nanoparticles was synthesized by the coprecipitation technique to explore the effect of annealing on the structure and some physical properties of the produced material. The coprecipitated sample consists of an orthorhombic strontium carbonate phase and the required cubic Co0.5Sr0.5Fe2O4. Annealing at elevated temperatures (900 °C) leads to the formation of cubic and hexagonal phases. This crystal structure was confirmed by X-ray diffraction analysis (XRD). The accuracy of the cation distribution of the cubic phase determined from the Rietveld analysis of XRD patterns is demonstrated by matching the experimental and theoretical lattice constants. There are several noticeable changes in aspects as the annealing temperature goes up. The transmission electron microscopy (TEM) images indicated that heating substantially affects the growth and densification of the smaller nanoparticles. There is a drop in the longitudinal and transverse wave velocities, bulk, rigidity, Young's moduli, Poisson ratio (σ), and Debye temperature (θD) with annealing and grain growth. The saturation magnetization and coercive field are enhanced with annealing. The particle size distribution calculated from TEM is confirmed and supported by the switching field distribution. The indirect optical bandgap energy (Eg) decreased with annealing. The present study concentrated on the thermal treatment impacts on various optical parameters, such as the refractive index and extinction coefficient. The optoelectrical parameters, such as the dielectric constant, dielectric loss, and optical and electrical conductivity, were extensively investigated, giving valuable insights, and their results were interpreted. These findings suggest potential applications in magnetic storage, sensors, and optoelectronics fields.

Antibacterial activity of green synthesized copper oxide nanoparticles against multidrug-resistant bacteria

Using plant extracts in the green synthesis of nanoparticles has become an environmentally acceptable approach. In our study, copper oxide nanoparticles (CuO NPs) were synthesized using ethanolic extracts of Azadirachta indica and Simmondsia chinensis. CuO NP formation was confirmed by the change in color and by UV‒visible spectroscopy (CuO NPs peaked at a wavelength of 344 nm). TEM images confirmed the semispherical shape of the CuO NPs, with particle sizes ranging from 30.9 to 10.7 nm. The antibacterial activity of these NPs was evaluated by using the agar diffusion method against clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa, Acinetobacter spp., Klebsiella pneumoniae, and Stenotrophomonas maltophilia. The minimum inhibitory concentration (MIC) of CuO NPs ranged from 62.5 to 125 µg/ml. In contrast, the antioxidant activity and antibiofilm activity of CuO NPs ranged from 31.1 to 92.2% at 125–500 µg/ml and 62.2–95%, respectively, at 125 –62.5 µg/ml. Our results confirmed that CuO NPs had IC50s of 383.41 ± 3.4 and 402.73 ± 1.86 at 250 µg/mL against the HBF4 cell line. Molecular docking studies with CuO NPs suggested that penicillin-binding protein 4 (PBP4) and beta-lactamase proteins (OXA-48) strongly bind to S. aureus and K. pneumoniae, respectively, with CuO NPs. Our study confirms the promising use of CuO NPs in treating pathogenic bacteria and that CuO NPs could be possible alternative antibiotics. This study supports the pharmaceutical and healthcare sectors in Egypt and worldwide.

Near‐Infinite‐Chain Polymers with Ge=Ge Double Bonds

Despite considerable interest in heteroatom‐containing conjugated polymers, there are only few examples with heavier p‐block elements in the conjugation path. The recently reported heavier acyclic diene metathesis (HADMET) allowed for the synthesis of a polymer containing Ge=Ge double bonds – albeit insoluble and with limited degree of polymerization. By incorporation of long alkyl chains, we now obtained soluble representatives, which exhibit degrees of polymerization near infinity according to diffusion‐ordered NMR spectroscopy (DOSY) and dynamic light scattering (DLS). Analyses of the UV/Vis absorption and the NMR spectroscopic data confirm the presence of σ,π‐conjugation across the silylene‐phenylene linkers between the Ge=Ge double bonds. Favorable intermolecular dispersion interactions lead to ladder‐like cylindrical supramolecular assemblies as confirmed by X‐ray diffraction (XRD), small angle X‐ray scattering (SAXS) and DLS. AFM and TEM images of deposited thin films reveal lamellar ordering of extended polymer bundles.

Near-Infinite-Chain Polymers with Ge=Ge Double Bonds.

Despite considerable interest in heteroatom-containing conjugated polymers, there are only few examples with heavier p-block elements in the conjugation path. The recently reported heavier acyclic diene metathesis (HADMET) allowed for the synthesis of a polymer containing Ge=Ge double bonds - albeit insoluble and with limited degree of polymerization. By incorporation of long alkyl chains, we now obtained soluble representatives, which exhibit degrees of polymerization near infinity according to diffusion-ordered NMR spectroscopy (DOSY) and dynamic light scattering (DLS). Analyses of the UV/Vis absorption and the NMR spectroscopic data confirm the presence of σ,π-conjugation across the silylene-phenylene linkers between the Ge=Ge double bonds. Favorable intermolecular dispersion interactions lead to ladder-like cylindrical supramolecular assemblies as confirmed by X-ray diffraction (XRD), small angle X-ray scattering (SAXS) and DLS. AFM and TEM images of deposited thin films reveal lamellar ordering of extended polymer bundles.

Effect of CTAB and NaBH4 Solutions on Ti and Cu Nanoparticles Prepared by Pulsed Laser Ablation

The effect of different media, including cetyltrimethylammonium bromide (CTAB) and sodium borohydride (NaBH4), on the size, shape, optical absorption, and stability of titanium (Ti) and copper (Cu) nanoparticles (NPs) synthesized by laser ablation in liquid, was investigated. Ti and Cu NPs were fabricated by irradiating Ti and Cu targets using a Nd:YAG pulsed laser with a wavelength of 1064 nm, an energy of 500 mJ, repetition rate of 1 Hz, and a number of pulses of 1000. Results showed the direct effect of the type of surfactant on the size and size distribution of Ti and Cu NPs under the same laser ablation parameters. Morphological properties were described by field emission scanning electron microscope (FESEM) images, which revealed the formation of semispherical particles. The EDS results confirmed the spike-induced synthesis of Ti and Cu in CTAB and NaBH4 solutions. The transmission electron microscopy (TEM) images showed the nanostructures of Ti and Cu with spherical particles. The UV-vis absorption spectra showed that the absorption peak of Ti was almost constant at 289 nm, while the peak of Cu disappeared for both solutions. Zeta potential analysis showed that NPs prepared in CTAB solution were more stable than those in NaBH4 solution.

Directing Charge Carriers and Ferroelectric Domains at Lateral Interfaces in van der Waals Heterostructures.

Emergent phenomena in traditional ferroelectrics are frequently observed at heterointerfaces. Accessing such functionalities in van der Waals ferroelectrics requires the formation of layered heterostructures, either vertically stacked (similar to oxide ferroelectrics) or laterally stitched (without equivalent in 3D-crystals). Here, we investigate lateral heterostructures of the ferroelectric van der Waals semiconductors SnSe and SnS. A two-step process produces ultrathin crystals comprising an SnSe core laterally joined to an SnS edge-band, as confirmed by Raman spectroscopy, transmission electron microscopy (TEM) imaging, and electron diffraction. TEM shows a moiré pattern across the SnSe core due to coverage by an ultrathin SnS layer. The ability of the lateral interface (IF) to direct excited carriers, probed by cathodoluminescence, shows electron transfer over 560 nm diffusion length from the SnS edge-band. Large, thin flakes supporting ferroelectricity allow investigating domains and domain wall interactions in uniform crystals and lateral heterostructures. Polarized optical microscopy of sub-20 nm flakes consistently shows ⟨110⟩ oriented stripe domains with mirror-twin domain walls. Heterostructures adopt two domain configurations, with domains either constrained to the SnSe core or propagating across the entire SnSe-SnS flakes. The combined results demonstrate multifunctional van der Waals heterostructures with high-quality IFs presenting extraordinary opportunities for manipulating carrier flows and ferroelectric domain patterns.

Formulation and characterization of cholesterol-based nanoparticles of gabapentin protecting from retinal injury.

This study aimed to prepare cholesterol and stearic acid-based solid lipid nanoparticles of gabapentin (GAB-SLNs) for protection against streptozotocin (STZ)-induced retinal injury in rats. We prepared four preparations of GAB-SLNs using a hot high-shear homogenization ultrasonication process, and the best formulation was selected and tested for biological activity. The retinal injury was brought in male adult albino rats while gabapentin doses continued for 6weeks. Six groups of rats were assigned as the vehicle, diabetic, diabetic + gabapentin (10-20mg/kg), and diabetic + GAB-SLNs (10-20mg/kg). GAB-SLN#2 was selected as the optimized formulation with high entrapment efficacy (EE%, 98.64% ± 1.97%), small particle size (185.65 ± 2.41nm), high negative Zeta potential (-32.18 ± 0.98mV), low polydispersity index (0.28 ± 0.02), and elevated drug release (99.27% ± 3.48%). The TEM image of GAB-SLN#2 revealed a smooth surface with a spherical shape. GAB-SLNs provided greater protection against retinal injury than free gabapentin as indicated by the histopathology data which demonstrated more organization of retinal layers and less degeneration in ganglion cell layer in rats treated with GAB-SLN#2. Further, GAB-SLN#2 reduced the inflammatory proteins (IL-6/JAK2/STAT3) and vascular endothelial growth factor (VEGF). The preparation of GAB-SLNs enhanced the physical properties of gabapentin and improved its biological activity as a neuroprotectant. Further studies are warranted to validate this technique for the use of oral gabapentin in other neurological disorders.