Scanning Transmission Research Articles

Tailoring Mechanical Reliability in Transparent ZnO-Zincone Thin-Film Electrodes with Organic Interlayer Interfaces and Thickness.

To address the inherent brittleness of conventional transparent conductive oxides, researchers have focused on enhancing their flexibility. This is achieved by incorporating organic films to construct organic-inorganic hybrid layer-by-layer nanostructures, where the interlayer thickness and interface play pivotal roles in determining the properties. These factors are contingent on the type of material, processing conditions, and specific application requirements, making it essential to select the appropriate conditions. In this study, ZnO-zincone nanolaminate thin films were fabricated using atomic layer deposition and molecular layer deposition in various structural configurations. Transmission electron microscopy, X-ray diffraction, and scanning electron microscopy were used to conduct a thorough analysis of the thin-film growth and structural transformations resulting from the deposition conditions. Furthermore, the influence of structural differences at the interfaces on the mechanical properties of the films was investigated by employing both tensile and compression-bending fatigue tests. This comprehensive examination reveals noteworthy variations in the mechanical responses of the films. Thin films characterized by internal porosity and an intermixed amorphous structure demonstrated enhanced compressive toughness, whereas rigid organic layers improved flexibility. These findings offer valuable insights into the development of flexible, transparent multilayer films.

Identification of porcine fast/slow myogenic exosomes and their regulatory effects on lipid accumulation in intramuscular adipocytes

BackgroundPork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus (EDL) and soleus (SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes.ResultsPorcine SOL-derived exosomes (SOL-EXO) and EDL-derived exosomes (EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc- shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO.ConclusionsOur findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.

Effect of pre-deformation on microstructure and mechanical properties of 2050 Al−Li alloy

The microstructural evolution and mechanical properties of 2050 Al−Li alloy subjected to different rolling pre-strains (0−20%) and aging (T8) were studied. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to characterize the microstructure. The results show that the grains were significantly refined along the normal direction (ND) and the intragranular distortion increased with the increase of pre-strain level. The entanglement of defects, e.g., dislocations, provides a large number of nucleation sites for the precipitation of T1 phases. This leads to larger number of precipitates and narrower distance between precipitates, thus improving the hindering effects on dislocation motions and the strength of the alloy. When the pre-deformation level reaches 16%, the alloy shows the highest density of T1 phases and strength (the yield strength and tensile strength reach 568 and 584 MPa, respectively, and elongation is 8.6%). When the amount of pre-deformation is further increased to 20%, the atomic diffusion channels are reduced due to dislocation entanglement, and the reduction in the number of T1 phases eventually leads to a decrease in strength of the alloy.

Hollow-magnetite/MXene nanohybrids with unique coral-like structure for electromagnetic wave absorption

The novel hollow-magnetite (HFO)/MXene nanohybrids with coral-like structure were successfully prepared via templating and electrostatic self-assembly techniques for electromagnetic (EM) wave adsorption application. The unique coral-like structure of the prepared HFO/MXene hybrids was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When mass ratio of HFO to MXene is 2:1, the maximum effective absorption bandwidth (EABmax) of HFO/MXene hybrids is able to reach 5.36 GHz. Moreover, when mass ratio of HFO to MXene is 1:1, the minimum reflection loss (RLmin) even achieves −42.48 dB with a thickness of 3.1 mm. The excellent EM absorption performance of HFO/MXene hybrids is mainly due to the ideal impedance matching and synergistic effect of magnetic loss and dielectric loss caused by unique coral-like structure. This work provides unexplored areas in the design of the spatial structure of MXene for microwave absorption.

Optimization of ammonia and TEOS concentration for the development of Ca(OH)2@SiO2 nanocomposites for optimal energy storage performance

In this study, nanocomposites of Calcium hydroxide (Ca(OH)2) and Silica (SiO2) were developed using tetraethylorthosilicate precursor, and the impact of ammonia concentration on the reaction kinetics of Ca(OH)2 to CaO conversion were studied. The Ca(OH)2 nanoparticles were synthesized by the sol-gel method. The formation of Ca(OH)2 particles was confirmed through X-ray diffraction. Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) provided evidence for the presence of a SiO2 layer on Ca(OH)2. Thermogravimetric analyses were carried out under N2 atmosphere to study the dehydration efficiency of the Ca(OH)2 system in the presence of SiO2. The results were found to be consistent with the findings from XRD and Raman analysis. Differential Scanning Calorimetry (DSC) was done to determine the impact of ammonia and silica on the endothermic peak of Ca(OH)2 and CaCO3. TG results were used to determine the weight loss, activation energy (Ea), entropy (ΔS), enthalpy (ΔH), and Gibbs free energy (ΔG).

Photocatalytic, antibacterial and antioxidant potential of spheroidal shape chromium and yttrium doped cobalt oxide nanoparticles: A green approach

This study delves into the versatile attributes of green synthesis of chromium doped cobalt oxide and yttrium doped cobalt oxide nanoparticles, synthesized through a sustainable process utilizing phytochemicals extracted from Bergera koenigii. The primary focus is on evaluating their effectiveness in photocatalysis, antibacterial activity, and antioxidant properties. The cubic structure of both chromium doped cobalt oxide and yttrium doped cobalt oxide nanoparticles was confirmed through X-ray diffraction analysis with crystallite size of 14.204 and 12.949 nm, respectively. Transmission electron microscopy and Scanning electron microscopy and Energy Dispersive X-ray spectroscopy examinations revealed the presence of spheroidal nanoparticles ranging from 37 to 41 nm in size. Photocatalytic efficiency, assessed through congo red dye degradation, demonstrated degradation of 86.963 and 94.499 % for chromium doped cobalt oxide and yttrium doped cobalt oxide nanoparticles, respectively. Antibacterial evaluations underscored the nanoparticles capacity to disrupt Bacillus subtilis and Escherichia coli, with yttrium doped cobalt oxide nanoparticles exhibiting superior antibacterial activity compared to chromium doped cobalt oxide nanoparticles. The antioxidant potential, evaluated via the 2,2-diphenyl-1-picrylhydrazyl free radical assay, showcased the nanoparticle's ability to scavenge free radicals, with yttrium doped cobalt oxide nanoparticles displaying highest scavenging up to 83.359 % which attributed to the introduced phytochemicals during the green synthesis process. The innovation of this research lies in the green synthesis of chromium doped cobalt oxide and yttrium doped cobalt oxide nanoparticles, harnessing their distinct properties for synergistic applications. The study provides valuable insights into potential future applications, offering novel solutions for environmental remediation and biomedical uses.

Green-synthesized zinc oxide nanoparticles by Enterobacter sp.: unveiling characterization, antimicrobial potency, and alleviation of copper stress in Vicia faba (L.) plants

BackgroundThe biosynthesis of zinc oxide nanoparticles (ZnO NPs) using Enterobacter sp. and the evaluation of their antimicrobial and copper stress (Cu+ 2)-reducing capabilities in Vicia faba (L.) plants. The green-synthesized ZnO NPs were validated using X-ray powder diffraction (XRD); Fourier transformed infrared (FTIR), Ultraviolet-Visible spectroscopy (UV-Vis), Transmission electron microscope (TEM) and scanning electron microscopy (SEM) techniques. ZnO NPs could serve as an improved bactericidal agent for various biological applications. as well as these nanoparticles used in alleviating the hazardous effects of copper stress on the morphological and physiological traits of 21-day-old Vicia faba (L.) plants.ResultsThe results revealed that different concentrations of ZnO NPs (250, 500, or 1000 mg L-1) significantly alleviated the toxic effects of copper stress (100 mM CuSO4) and increased the growth parameters, photosynthetic efficiency (Fv/Fm), and pigments (Chlorophyll a and b) contents in Cu-stressed Vicia faba (L.) seedlings. Furthermore, applying high concentration of ZnO NPs (1000 mg L-1) was the best dose in maintaining the levels of antioxidant enzymes (CAT, SOD, and POX), total soluble carbohydrates, total soluble proteins, phenolic and flavonoid in all Cu-stressed Vicia faba (L.) seedlings. Additionally, contents of Malondialdehyde (MDA) and hydrogen peroxide (H2O2) were significantly suppressed in response to high concentrations of ZnO NPs (1000 mg L-1) in all Cu-stressed Vicia faba (L.) seedlings. Also, it demonstrates strong antibacterial action (0.9 mg/ml) against various pathogenic microorganisms.ConclusionsThe ZnO NPs produced in this study demonstrated the potential to enhance plant detoxification and tolerance mechanisms, enabling plants to better cope with environmental stress. Furthermore, these nanoparticles could serve as an improved bactericidal agent for various biological applications.

Advanced structure research methods of amorphous Co69Fe4Cr4Si12B11 microwires with giant magnetoimpedance effect: Part 3 – Cluster growth and crystal nucleation

This Part 3 focuses on the detailed study of the nanostructures forming in amorphous microwires which were previously received and described in the Part 2. The clustering process was studied at long-term DC Joule heating’s much lower the crystallization temperature. Particular attention is paid to the study of the redistribution of the components of the initial stage of crystallization. The studies were carried out using the Atom Probe Tomography method (APT), which allows for the identification of individually considered atoms. A description and analysis of APT data processing techniques are provided for studying the cluster structure and distribution of elements in the amorphous matrix and crystalline phases. To identify crystalline phases, data obtained using High-Resolution Transmission Electron Microscopy (HR-TEM) and Scanning Transmission Electron Microscopy (STEM), as well as X-Ray Powder Diffraction (XRPD) with synchrotron radiation source were used. The applied techniques made it possible to establish that the formation of nuclei of crystalline phases is preceded by three stages of the amorphous microwire matrix evolution. At the first stage, clusters of the first and second coordination spheres appear. At the second stage, the clusters coagulate and become more than 2 nm in diameter, the stage ends with the predominance of Co-rich and silicide Me-Si clusters. At the third stage, they grow to an average diameter of 4.5 nm, the predominance of clusters of this type remains, and the formation of nuclei of crystalline phases α-Co and Co2Si, with a size of about 8 nm, occurs. This stage is characterized by high stable soft magnetic properties. With a further increase in the heat treatment temperature, a gradual deterioration of the soft magnetic properties and further structural transformation occur – structures of joint crystalline phases from two crystalline phases α-Co and Co2Si are formed in the amorphous matrix, and crystallization occurs with the alternation of these two phases. This leads to a significant redistribution of alloy components. As a result, an amorphous barrier layer is formed in the amorphous matrix near the surface of the growing two-phase substructures, enriched in chromium and silicon; this layer affects the growth of crystalline phases, slowing it down.

The trophoblast surface becomes refractory to adhesion by congenitally transmitted Toxoplasma gondii and Listeria monocytogenes during cytotrophoblast to syncytiotrophoblast development.

The placenta is a critical barrier against viral, bacterial, and eukaryotic pathogens. For most teratogenic pathogens, the precise molecular mechanisms of placental resistance are still being unraveled. Given the importance of understanding these mechanisms and challenges in replicating trophoblast-pathogen interactions using in vitro models, we tested an existing stem-cell-derived model of trophoblast development for its relevance to infection with Toxoplasma gondii. We grew human trophoblast stem cells (TSCT) under conditions leading to either syncytiotrophoblast (TSSYN) or cytotrophoblast (TSCYT) and infected them with T. gondii. We evaluated T. gondii proliferation and invasion, cell ultrastructure, as well as for transcriptome changes after infection. TSSYNs cells showed similar ultrastructure compared to primary cells and villous explants when analyzed by transmission electron microscopy and scanning electron microscopy (SEM), a resistance to T. gondii adhesion could be visualized on the SEM level. Furthermore, TSSYNs were highly refractory to parasite adhesion and replication, while TSCYTs were not. RNA-seq data on mock-treated and infected cells identified differences between cell types as well as how they responded to T. gondii infection. We also evaluated if TSSC-derived SYNs and CYTs had distinct resistance profiles to another vertically transmitted facultative intracellular pathogen, Listeria monocytogenes. We demonstrate that TSSYNs are highly resistant to L. monocytogenes, while TSCYTs are not. Like T. gondii, TSSYN resistance to L. monocytogenes was at the level of bacterial adhesion. Altogether, our data indicate that stem-cell-derived trophoblasts recapitulate resistance profiles of primary cells to T. gondii and highlight the critical importance of the placental surface in cell-autonomous resistance to teratogens.IMPORTANCECongenital toxoplasmosis can cause a devastating consequence to the fetus. To reach the fetus's tissues, Toxoplasma gondii must cross the placenta barrier. However, how this parasite crosses the placenta and the precise molecular mechanisms of placental resistance to this parasite are still unknown. In this study, we aimed to characterize a new cellular model of human trophoblast stem cells to determine their resistance, susceptibility, and response to T. gondii. Syncytiotrophoblast derived from trophoblast stem cells recapitulate the resistance profile similarly to placenta cells. We also showed that these cells are highly resistant to Listeria monocytogenes, at the level of bacterial adhesion. Our results suggest that resisting pathogen adhesion/attachment may be a generalized mechanism of syncytiotrophoblast resistance, and trophoblast stem cells represent a promising model to investigate cell-intrinsic mechanisms of resistance to pathogen adhesion and replication.

Morphology and biological responses of nanocomposites of hydroxyapatite, graphene oxide, and dysprosium oxide (Dy2O3) for biomedical applications

In this research study, various nanocomposites, namely Dy2O3, Sm2O3, HAP/Dy2O3, HAP/Dy2O3/GO, and HAP/Sm2O3/GO, were extensively examined and analyzed. The primary focus was on the development of advanced biomaterials with improved mechanical properties, biocompatibility, and antimicrobial activity. The investigation involved the use of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques to observe the distinctive nanorods of hydroxyapatite (HAP) within the ternary nanocomposite. The SEM micrographs yielded an average size of 69 ± 22 * 19 ± 4 nm for the HAP nanorods, accompanied by an average roughness measurement of 10.5 nm. The TEM analysis provided further insights into the distribution of HAP and Sm2O3 within graphene oxide (GO) nanosheets, revealing HAP particles measuring 20 nm in size and 65 nm in length, and Sm2O3 particles measuring 6 nm in size. To evaluate the biocompatibility of the newly developed ternary nanocomposite, HAP/Dy2O3/GO, osteoblast cells were employed. The results showed a minor decrease in cell viability, with a measured percentage of cell viability at 97.5 ± 2.1 %. Furthermore, the HAP/Dy2O3/GO nanocomposite exhibited notable antibacterial properties against E. coli and S. aureus bacteria, as indicated by inhibition zones measuring 15.3 ± 0.8 mm and 15.9 ± 1.1 mm, respectively. The unique composition of HAP/Dy2O3/GO demonstrated enhanced roughness parameters and improved biocompatibility due to its altered topological features. Additionally, its remarkable antibacterial activity and robust mechanical strength establish HAP/Dy2O3/GO as a promising candidate for further investigation as a biomaterial for bone implants.

Synthesis and characterization of hydroxyapatite nanoparticles from calcium hydroxide fouled with gases evolved from smokestack of glass industry

In glass industry, the evolved gases and fumes from burning the gas fuel absorbed in calcium hydroxide to minimize the pollution of environment. After a period of time, the calcium hydroxide fouled with sulphate and carbonate as action of the absorbed SO3 and CO2 gases. Based on our interest to treatment the solid waste materials, this study intended to convert the obtained waste of calcium hydroxide fouled with gases to valuable products. Firstly, this waste was treated with water, caustic soda and acids. The results confirmed the conversion of waste to pure calcium sulfate by treatment with 6 v/v% sulfuric acid. Secondly, the obtained calcium sulfate was reacted with ammonium dihydrogen phosphate solution for preparation of calcium hydroxyapatite (HAp) nanoparticles. The produced HAp sample was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and N2 adsorption measurements. The obtained findings confirmed that the HAp can be produced after calcination at 700 °C, nanorods-like of sizes ranged from 11 to 15 nm and with main surface functional groups of hydroxyapatite. TGA and DTA data indicated that HAp is thermally stable up to 700 °C. Also, the obtained HAp has Ca/P molar ratio of 1.60 and exhibited high total surface area of 146 m2/g with mesoporous structure which make this material can be used in medical and water purification applications.

Atomic-level investigation of structure and formation process of Y3Al5O12 with super-high content of Ce emitting anomalous orange-red emissions

Ce-doped yttrium aluminum garnet (YAG:Ce, Y3Al5O12:Ce) is the most commonly used yellow phosphor in white light-emitting diodes. Recently, we found that (Y1–xCex)3Al5O12:Ce with a super-high content of Ce (x = 0.11–0.21) can be prepared by a polymerized complex method and exhibits anomalous orange–red emission. To understand the nature of this anomalous behavior from the atomic level, we applied high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and scanning transmission electron microscopy–energy dispersive X-ray spectroscopy (STEM-EDS), a state-of-the-art technique that enables analysis of the atomic-level elemental distributions of Al, Y, and Ce. STEM-EDS images on the atomic level were successfully obtained for YAG:Ce. It was found that Ce in Y site has spatially uneven for few nanometers. Ce–K edge extended X-ray absorption fine structure (EXAFS) analysis was also conducted, which revealed a high level of asymmetry around Ce. By combining the STEM-EDS and EXAFS results, a dynamic model for the red emission was proposed. STEM-EDS also revealed that CeO2 nanocrystals were firstly formed with low-temperature annealing and that the reaction of Y with the CeO2 nanocrystals subsequently yielded YAG:Ce, unlike in the conventional one-step high-temperature synthesis.

Controlled Size Characterization Process for In-Situ TiB2 Particles from Al Matrix Composites Using Nanoparticle Size Analysis.

The wide size range and high tendency to agglomerate of in-situ TiB2 particles in reinforced Al matrix composites introduce great difficulties in their size characterization. In order to use a nanoparticle size analyzer (NSA) to obtain the precise size distribution of TiB2 particles, a controlled size characterization process has been explored. First, the extraction and drying processes for TiB2 particles were optimized. In the extraction process, alternated applications of magnetic stirring and normal ultrasound treatments were proven to accelerate the dissolution of the Al matrix in HCl solution. Furthermore, freeze-drying was found to minimize the agglomeration tendency among TiB2 particles, facilitating the acquisition of pure powders. Such powders were quantitatively made into an initial TiB2 suspension. Second, the chemical and physical dispersion technologies involved in initial TiB2 suspension were put into focus. Chemically, adding PEI (M.W. 10000) at a ratio of mPEI/mTiB2 = 1/30 into the initial suspension can greatly improve the degree of TiB2 dispersion. Physically, the optimum duration for high-energy ultrasound application to achieve TiB2 dispersion was 10 min. Overall, the corresponding underlying dispersion mechanisms were discussed in detail. With the combination of these chemical and physical dispersion specifications for TiB2 suspension, the bimodal size distribution of TiB2 was able to be characterized by NSA for the first time, and its number-average diameter was 111 ± 6 nm, which was reduced by 59.8% over the initial suspension. Indeed, the small-sized and large-sized peaks of the TiB2 particles characterized by NSA mostly match the results obtained from transmission electron microscopy and scanning electron microscopy, respectively.

Systematic study of FIB-induced damage for the high-quality TEM sample preparation

Nowadays, a focused Ga ion beam (FIB) with a scanning electron microscopy (SEM) system has been widely used to prepare the thin-foil sample for transmission electron microscopy (TEM) or scanning TEM (STEM) observation. An establishment of a solid strategy for a reproducible high-quality sample preparation process is essential to carry out high-quality (S)TEM analysis. In this work, the FIB damages introduced by Ga+ beam were investigated both experimentally and stopping and range of ions in matter (SRIM) simulation for silicon (Si), gallium nitride (GaN), indium phosphide (InP), and gallium arsenide (GaAs) semiconductors. It has been revealed that experimental investigations of the FIB-induced damage are in good agreement with SRIM simulation by defining the damage as not only “amorphization” but also “crystal distortion”. The systematic evaluation of FIB damages shown in this paper should be indispensable guidance for reliable (S)TEM sample preparation.

THE DESIGN AND CHARACTERIZATION OF MODIFIED POLYTHIOPHENE SUPPORTED PLANT MEDIATED CO-NI BIMETALLIC NANOCOMPOSITES

Ficus mucuso leaf extract was employed as reducing agent in the synthesis of Co-Ni bimetallic nanoparticles (BMNPs) with two precursors namely; Cobalt (ii) nitrate hexahydrate; [CO(NO3)2.6H2O] and nickel (ii) nitrate hexahydrate; [Ni (NO3)2.6H2O]. Afterwards, acid modified polythiophene was synthesized through the in-situ and ex-situ coupling approach. The nanocomposite obtained from the in-situ method was labelled ‘A’ and that of the ex-situ, ‘B’. The in-situ approach was considered to be more appropriate for synthesizing the BMNPs as confirmed by characterization using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), Energy dispersive X-ray (EDX) analysis, Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM) techniques. The hexagonal cobalt and the cubic nickel were investigated using XRD to determine the particle sizes taking Debye-Scherrer’s equation to be around 14.495nm for sample A and 15.689nm for sample B. This was reported to be responsible for the corresponding intense peak at A over B. The SEM and TEM measurements portray good correlation indicating the presence of agglomerates in sample B. The EDS analysis taken reported a higher weight of the cobalt and nickel compositions in A than in B. TGA explained the higher decomposition rate of B than A. Also, a more pronounced intense peak was observed in A than in B using FTIR technique. This comparison of both samples makes in-situ synthesis unquestionably the best because of its outstanding performance over ex-situ approach. This is the first report of Ficus Mucuso plant extract being used in nanosynthesis.

Green synthesis of metal nanoparticles from Codium macroalgae for wastewater pollutants removal by adsorption

AbstractAlgae have adsorption properties and reducing agents due to their rich content. In this study, palladium nanoparticles (Pd NP), platinum nanoparticles (Pt NP), and iron oxide nanoparticles (Fe3O4 NP) were prepared from Codium macroalgae using green synthesis. The structure of the synthesized nanoparticles was elucidated by X‐ray diffractometry, Fourier transforms infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy, ultraviolet‐visible spectroscopy and scanning electron microscopy‐energy dispersive X‐ray spectrometry and their use as nanoadsorbents for the removal of pollutants from aqueous media was investigated in detail. Naproxen (NPX), an anti‐inflammatory drug, and the dyes methylene blue (MB) and cresol red (CR) were selected as pollutants for this study. Batch adsorption experiments were conducted using both real wastewater obtained from the Organised Industrial Zone of Isparta Province and synthetic water samples prepared with tap water from Burdur Province and pure water. Under optimum adsorption conditions, Pd NP showed significant efficiency in the real wastewater sample, with an adsorption capacity of 37.19 and 50.03 mg g–1 for CR and NPX, respectively, within 150 min. In comparison, Pt NP showed an adsorption capacity of 40.01 mg g–1 for MB within the same timeframe. These findings indicate that while Pd NP showed the highest adsorption capacity for both CR and NPX, Pt NP showed the highest adsorption capacity for MB. The Langmuir model and the pseudo‐second‐order equation were more suitable to describe the adsorption behavior of CR, MB, and NPX. In addition, studies on the desorption and reusability of the nanoadsorbents were carried out under the same optimum experimental conditions.

Catalytic Degradation Efficacy of Silver Nanoparticles Fabricated Using Actinidia deliciosa Peel Extract

The preparation of metallic nanoparticles using green synthetic approaches and its application toward the efficient degradation of environmentally hazardous dyes constitutes an attractive alternative to currently employed methods. In the current report, the green synthesis of silver nanoparticles (AgNPs) was successfully achieved using Actinidia deliciosa (kiwifruit) peel aqueous extract as a bioreducing agent under optimized synthesis conditions. The experimental parameters were optimized in terms of reactant ratio, reaction temperature, and reaction time. The biogenic nanoparticles exhibited SPR absorption band at λmax 480 nm. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images revealed quasispherical monodisperse nanoparticles which were 36 nm in diameter. The hydrodynamic diameter of the nanoparticles was 106 nm as determined by dynamic light scattering, and the highly negative ζ-potential (−34 mV) supported its superior colloidal stability. Energy dispersive X-ray confirmed that silver is a major constituent of the nanoparticles. X-ray diffraction (XRD) diffractograms confirmed the crystallinity of the nanoparticles and its face-centered cubic (fcc) lattice structure. The functional groups in the plant’s phytochemicals facilitating the reduction of Ag+ ions and stabilization of the formed AgNPs were identified by fourier transform infrared (FTIR) spectroscopy. In specific, the bands in the FTIR spectra at 3,412, 1,618, 1,419, and 1,237 cm−1 suggested the presence of phenolic compounds. Phytochemical analysis by colorimetric assays revealed that the kiwifruit peel extract was rich in phenolic compounds. When evaluated in the catalytic degradation of organic dyes, the biosynthesized AgNPs induced instant and complete discoloration of the methylene blue dye when 1.6 mg of nanoparticles was used. At a lower dose of AgNPs (0.4 mg), 80% degradation of the dye occurred after 3 hr of treatment. The degradation reaction followed second-order kinetics with a rate constant of 0.01083 mM−1s−1. The current study highlights the immense potential of the prepared nanoparticles as efficient catalysts for the degradation of hazardous organic dyes such as methylene blue and presents an intriguing argument for investigating the catalytic efficiency of the biogenic AgNPs for the degradation of other structurally different dye pollutants.

Comparative ultrastructure of the olfactory system in the East African root rat (Tachyoryctes splendens) and the naked mole rat (Heterocephalus glaber).

The ultrastructure of the olfactory system of most fossorial rodents remains largely unexplored. This study sought to investigate the functional structure of the olfactory mucosa and olfactory bulb of two species of fossorial rodents that have distinct behaviour and ecology, the East African root rat (RR) and the naked mole rat (NMR). Transmission electron microscopy and scanning electron microscopy were employed. The basic ultrastructural design of the olfactory system of the two species was largely comparable. In both species, the olfactory mucosa comprised an olfactory epithelium and an underlying lamina propria. The olfactory epithelium revealed olfactory knobs, cilia and microvilli apically and sustentancular cells, olfactory receptor neurons and basal cells in the upper, middle and basal zones, respectively. The lamina propria was constituted by Bowman's glands, olfactory nerve bundles and vasculature supported by loose connective tissue. Within the olfactory bulb, intracellular and extracellular structures including cell organelles, axons and dendrites were elucidated. Notable species differences were observed in the basal zone of the olfactory epithelium and on the luminal surface of the olfactory mucosa. The basal zone of the olfactory epithelium of the RR consisted of a single layer of flattened electron-dense horizontal basal cells while the NMR had juxtaposed electron-dense and electron-lucent heterogenous cells, an occurrence seen as being indicative of quiescent and highly proliferative states of the olfactory epithelia in the two species, respectively. The olfactory epithelial surface of the NMR comprised an elaborate cilia network that intertwined extensively forming loop-like structures whereas in the RR, the surface was rugged and consisted of finger-like processes and irregular masses. With gross and histological studies showing significant differences in the olfactory structures of the two species, these findings are a further manifestation that the olfactory system of the RR and the NMR have evolved differently to reflect their varied olfactory functional needs.

Synthesis, anticancer, anti‐inflammatory, antimicrobial activities, molecular docking, and Density functional theory studies of nanometal (IV) glycoconjugates

Oxovanadium (IV) and diphenyltin (IV) complexes were synthesized on the nanoscale based on the Schiff base (H2L) derived from salicylaldehyde and d‐glucosamine. The complexes were formed with a molar ratio of 1:1 and 1:2 (metal: dligand) relative to oxovanadium (IV) and diphenyltin (IV), respectively. Fourier‐transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance, mass fragmentations, electronic transitions, thermogravimetric analysis, and density functional theory were employed to validate the structure of synthesized compounds. The results demonstrated that the ligand (H2L) was successfully attached to oxovanadium (IV) and diphenyltin (IV) as di‐anionic and mono‐anionic ligands, respectively. The size of the complexes was investigated using the transmission scanning microscope. The work presents a prospective concept for the drug design of the targeted anticancer through the glucose moiety. All compounds revealed remarkable anticancer activities against the colorectal (HCT‐116) cell line, recording IC50 values 4.94, 21.73, and 62.5 μg/ml for VO (II)(L), free H2L, and Sn (ph)2(HL)2, respectively. The IC50 value of VO (II)(L) complex was increased after the quercetin inhibitor. Therefore, the sugar‐conjugated compound can be recognized by the glucose recognition binding site of GLUT and their cell‐killing effect depends highly on the GLUT inhibitor, quercetin. The potential GLUT transportability of the compounds was investigated through a molecular docking study. The anti‐migration activity was investigated for VO (II)(L) complex. The free ligand observed the best antimicrobial results. The antibacterial stimulation was investigated and represented different interaction types with the selected ribosyl transferase enzyme.

Defect-regulated synthesis of ZrB2 powders via carbon thermal reduction and elucidation of its hot-pressing densification mechanism

Through defect modulation, ZrB2 powder was controllably synthesized using the carbon thermal reduction (CTR) method, with boron powder serving as a novel additive. Thermodynamic data for the ZrO2-B2O3-C system in the presence of boron were calculated using HSC thermodynamic software. Additionally, TG-DSC thermal analysis combined with XRD was used to investigate the reaction process. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to analyze the defect structure and grain surface characteristics of the reaction products. The results indicate that the reaction of B with ZrO2 and C exothermically alters the nucleation environment of ZrB2 grains. The helical dislocations generated act as a source of crystal growth steps, promoting the growth of smooth interfaces and leading to a transformation of the ZrB2 grain growth mechanism. Quantitative calculations of the dislocation density of ZrB2 powders, using the convolutional multiple whole profile fitting (CMWP-fit), suggest that the inclusion of boron as an additive can modulate the defect concentration of the products. ZrB2 powders with varied dislocation densities were achieved through meticulously controlled synthesis methods, followed by subsequent densification via hot pressing sintering. The results indicated that the relative density of ZrB2 ceramics increased from 83.9 % to 96.7 % as the dislocation density of the powder increased from 2.7 × 1013 m−2 to 7.6 × 1014 m−2 with the rise in boron content from 0 wt% to 3 wt%. In addition, the defects create extra sintering-driving forces that induce a shift in the densification mechanism from grain boundary diffusion to dislocation slip during hot-pressing sintering. This shift results in an increase in the apparent activation energy from 105 kJ/mol to 210 kJ/mol.