Search Results (1,299)

Aluminum nitride (AlN) possesses an exceptional combination of high thermal conductivity and an ultra-wide band gap, rendering it highly attractive for electronic packaging and semiconductor substrate applications. In this study, surface chemical modification of AlN powders was performed employing low-molecular-weight organic acids, successfully yielding hydrolysis-resistant AlN powders. The underlying mechanisms responsible for the improved anti-hydrolysis performance imparted by both single organic acids and the composite acid were systematically investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM), characterization techniques. The results reveal that Oxalic acid within the concentration range of 0.25 M to 1.50 M partially inhibits the hydrolysis of aluminum nitride (AlN); however, hydrolysis products such as aluminum hydroxide are still formed. In the case of citric acid, a higher concentration leads to a stronger anti-hydrolysis effect on the modified AlN. No significant hydrolysis products were detected when the AlN sample was treated in a 1 M aqueous citric acid solution at 80 °C. The effectiveness of the organic acids in enhancing the hydrolysis resistance of AlN follows the order: composite acid (citric acid + oxalic acid) > citric acid > oxalic acid. Under the action of the composite acid, the AlN diffraction peaks exhibit the highest intensity. Furthermore, TEM observations reveal the formation of an amorphous protective layer on the surface, which contributes to the improved hydrolysis resistance. Analytical results confirmed that the surface modification process, mediated by citric acid, oxalic acid, or the composite acid, involved an esterification-like reaction between the surface hydroxyl groups on AlN and the chemical modifiers. This reaction led to the formation of a continuous protective coordination layer encapsulating the AlN particles, which serves as an effective diffusion barrier against water molecules, thereby significantly inhibiting the hydrolysis reaction. Full article

Magnetotactic bacteria (MTB) have attracted interest in recent years, mainly due to their natural ability to form intracellular magnetic nanocrystals with potential for biomedical and environmental applications. In this study, we focused on the morphological analysis of the Paramagnetospirillum magnetotacticum MS-1 strain, trying to keep the bacteria as close to their natural state as possible. An important element of this work is the use of untreated bacterial cells, without conductive coating or chemical fixation, using a simple and low-cost support. This choice was made intentionally to avoid changes induced by metallization and to allow direct observation of characteristics that may be relevant in applications where the interaction of the bacteria with the environment plays an important role, such as biosensors. In addition, the analysis was performed on a bacterial suspension stored for approximately 10 months at 4 °C to assess whether the morphology specific to the MS-1 strain is maintained over time. The obtained results show that the general cell morphology and magnetosome organization can be clearly and reproducibly observed even after long-term storage. Without attempting to replace studies based on conventional sample preparation methods, this work provides a complementary perspective and suggests that magnetotactic bacteria may represent a natural and effective alternative to synthetic magnetic nanoparticles, with potential applications in the biomedical and environmental fields. Full article

A series of novel Ce-modified MnCoAl layered double oxides (Ce/MCA LDOs) were prepared using solvothermal and impregnation methods for NH₃-SCR denitration. Various characterizations, such as X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and H₂ temperature-programmed reduction (H₂-TPR) were used to investigate their structural properties and the mechanism of ammonia selective catalytic reduction (NH₃-SCR). The incorporation of Ce was found to effectively integrate into the LDO framework and enhance the catalytic activity over a wide temperature window. Moreover, the thermal stability and resistance of H₂O and SO₂ were evaluated. In situ DRIFTS studies revealed that the reaction follows both the “Langmuir–Hinshelwood” (L–H) and “Eley–Rideal” (E–R) mechanisms. This work provides systematic insights into the design of LDO-based catalysts, demonstrating their potential for practical application in denitration. Full article

The contamination of water bodies by polycyclic aromatic hydrocarbons (PAHs) poses a significant concern for the ecological systems, along with public health. Magnetic adsorption stands out as a green and practical solution for treating polluted water. To make the process more efficient and economical, it is important to create materials that not only absorb contaminants effectively but also allow for easy recovery and reuse. This study proposes a simple yet effective method for coating Fe₃O₄ nanoparticles with hydroxypropyl-β-cyclodextrin polymer (HP-β-CDCP). The physicochemical properties of the synthesized sorbent were characterized using a transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Vibrating Sample Magnetometer (VSM) analysis. The adsorption performance of HP-β-CDCP/Fe₃O₄ nanoparticles was well-described by the pseudo-second-order kinetic model, thermodynamic analysis, and the Freundlich isotherm model, indicating multiple interaction mechanisms with PAHs, such as π–π interactions, hydrogen bonding, and van der Waals forces. Using HP-β-CDCP/Fe₃O₄ nanoparticles as the adsorbent, the purification rates for the fifteen representative PAHs were achieved within the range of 33.9–93.1%, compared to 15.3–64.8% of the unmodified Fe₃O₄ nanoparticles. The adsorption of all studied PAHs onto HP-β-CDCP/Fe₃O₄ nanocomposites was governed by pH, time, and temperature. Equilibrium in the uptake mechanism was obtained within 15 min, with the largest adsorption capacities for PAHs in competitive adsorption mode being 6.46–19.0 mg·g⁻¹ at 20 °C, pH 7.0. This study points to the practical value of incorporating cyclodextrins into tailored polymer frameworks for improving the removal of PAHs from polluted water. Full article

Objective: To explore the preventive effect and mechanism of melatonin on high-fructose-induced renal injury in mice. Methods: A total of forty male C57BL/6J mice aged six weeks were randomly assigned to four groups: control group (CON), melatonin group (MLT), fructose group (FRU), and fructose + melatonin group (FRU + MLT). The concentration of the fructose solution was 30%, and the dose of melatonin was 10 mg/kg/day by intragastric administration. The experiment lasts for 10 weeks. Results: Liquid intake and energy intake were comparable between the FRU and FRU + MLT, both of which were significantly higher than that in the CON and MLT. MLT inhibited fructose-induced increased levels in serum creatinine (Cre), serum urea nitrogen (BUN), serum uric acid (UA), serum triglyceride (TG), renal kidney injury molecule-1 (KIM-1), and renal TG. Hematoxylin and Eosin (H&E) staining and Oil Red O (ORO) staining showed that MLT alleviated renal tubular dilatation, loss of brush border, epithelial cell detachment and lipid accumulation. Transmission electron microscope (TEM) observations showed that MLT increased autophagic vacuoles among mitochondria. Western blot analysis showed that, compared with the FRU, the FRU + MLT had elevated expression of AMP-activated protein kinase (AMPK) phosphorylation, along with a significant increase in the expression of its downstream mitophagy-related proteins (including PINK1, Parkin, LC3 II, and Beclin1), whereas the expression of p62 was markedly decreased. Furthermore, the expression levels of FAO-related proteins (including PPARα and CPT1A) in the FRU + MLT were significantly upregulated. Conclusions: MLT alleviates renal injury caused by high-fructose exposure in male mice and its mechanism might be associated with the regulation of mitophagy and fatty acid oxidation. Full article

Modern olive breeding points to a plant model characterized by low vigour, high productivity, and resistance to biotic and abiotic stresses, all traits required by the intensive and superhigh-density (SHD) systems of olive tree growing. The Italian Don Carlo and FS-17 Favolosa stand out among the new cultivars that are being tested. They were obtained not by breeding but by mass selection from two seedling populations of the Frantoio cultivar (maternal parent). Here, a multidisciplinary approach was used to determine the paternal parent of Don Carlo and FS-17, and then to investigate the inheritance of interesting traits such as fruit cell dimensions and oil content in these cultivars. Microsatellites were applied in phylogeny and kinship analyses, along with two functional markers previously developed on OeACP1 and OeACP2 genes. Ascolana Tenera cultivar was identified as the paternal parent of both new cultivars. This result was also supported by the analysis of the self-incompatibility group of the new cultivars and their most likely paternal parents. Light and electron microscopy [Cryo Scanning Electronic Microscopy (CRYO-SEM), Electronic Scanning Microscopy (E-SEM), and Transmission Electron Microscope (TEM)] techniques were used to analyze the fruit development concerning oil accumulation. Significant differences in cuticle thickness, size and shape of mesocarp and exocarp cells, and oil content were detected among cultivars. Our results suggested that the rearrangement of the traits studied led to an improved progeny compared to the parents. FS-17 exhibited an oil storage efficiency higher than Frantoio. Don Carlo showed fruit traits and oil content almost intermediate between the parents, making it a dual-purpose cultivar. Full article

In this article, the Ni-TiN coatings deposited on the surface of Q235 steel substrate via a magnetic-assisted electrodeposition approach. The surface morphology, Ti content, phase structure, and corrosion resistance of Ni-TiN coatings were investigated using a scanning electron microscope (SEM), a transmission electron microscopy (TEM), an energy disperse spectroscopy (EDS), an X-ray diffraction (XRD) instrument, and electrochemical workstation facility, respectively. SEM images showed that the surface morphology and thickness value of Ni-TiN coatings prepared at 0.7 T were superior to those obtained at 0.3 T and 1.1 T. EDS and adhesion strength results presented that the Ti content and adhesion strength of Ni-TiN coatings was lower than those produced at 0.7 T and 1.1 T. Meanwhile, Ni-TiN coatings prepared at 0.7 T possessed the highest hardness of 817.3 Hv. XRD patterns exhibited the nickel diffraction peaks of the Ni-TiN coatings fabricated at 0.7 T were broad and low, demonstrating that the size of nickel grain was fine. In comparison to other two Ni-TiN coatings, the one manufactured at 0.7 T possessed a high corrosion potential and a low corrosion current density, illustrating its outstanding corrosion resistance. Corrosion surface morphology revealed that the obvious corrosion pits emerged on the surface of Ni-TiN coatings deposited at 0.3 T, while the obvious corrosion pits were not appeared on the surface of Ni-TiN coatings manufactured at 0.7 T. In addition, the average corrosive weight loss of Ni-TiN coatings prepared at 0.7 T possessed the lowest of 7.2 mg, indicating the excellent corrosion resistance. Full article

In September 2024, an acute hemorrhagic diarrhea occurred in a colony of captive ring-tailed lemurs (Lemur catta) housed adjacent to an enclosure of squirrel monkeys in Henan Province, China. Three of the ring-tailed lemurs (1-year-old females) died, and necropsy revealed severe cecal hemorrhage. Histopathology demonstrated extensive mucosal necrosis, hemorrhage, and inflammatory cell infiltration in the cecum, with parasite adhesion and invasion into the crypts. Microscopic examination and PCR targeting the ITS1-5.8S-ITS2 region (347 bp) confirmed the presence of T. mobilensis in the deceased lemurs’ intestinal contents and in feces from 40.0% (4/10) of the squirrel monkeys. Ultrastructural analysis (SEM/TEM) confirmed that the isolated parasites exhibited the morphology and key features of T. mobilensis, including prominent peripheral hydrogenosomal vesicles. Treatment with metronidazole and supportive care led to the recovery of the surviving lemurs. Post-treatment fecal exams of ring-tailed lemur were negative for T. mobilensis. This report provides the first evidence of T. mobilensis infection in ring-tailed lemurs, indicating cross-species transmission from squirrel monkeys to lemurs, likely facilitated by keeper-mediated mechanical transmission via tools and footwear that were used in both enclosures. Full article

Citri grandis exocarpium (Citri grandis) has been consumed by human beings for fifteen hundred years. It is commonly consumed as a health drink and dietary supplement in China. However, its nutritional and healthcare functions are still not fully understood. Objective: Our previous study found that oral administration of Citri grandis extract can significantly decrease the blood lipid levels of hyperlipidemic mice fed a high-fat diet. The aim of this study was to confirm the preventative effects of Citri grandis extract against atherosclerosis. Methods: Atherosclerotic lesion models were induced in HUVECs and apoE^−/− C57BL/6J mice. ApoE^−/− mice fed a high-fat diet were orally administered Citri grandis extract (0.4, 0.8, and 1.6 g/kg/d BW) and Simvastatin (1 mg/kg/d BW) on the first day of model establishment. After a 16-week treatment, serum samples and aorta and liver tissues were collected. Observation of pathological changes in aortic and liver tissues was performed using a light microscope with oil red O, H&E, Masson’s trichrome staining, and TEM. Biochemical detection was employed to determine the serum levels of TC, TG, LDL-C, and HDL-C as well as the activities of AST and ALT. In addition, expression studies of TGF-β, PI3K, AKT1, PPAR-γ, LXR-α, and ABCA1 were performed via qPCR and Western blot analysis. Results: Compared with cholesterol-induced HUVECs, Citri grandis extract significantly enhanced cell viability, attenuated the morphological changes in HUVECs, and reduced LDH release. Furthermore, after treatment with Citri grandis extract, the levels of TC, TG, and LDL-C significantly decreased in the atherosclerosis model apoE^−/− mice after 16 weeks, and aortic plaque, lipid deposition, and endothelial injury were obviously ameliorated. The mRNA and protein expression of TGF-β, PPAR-γ, LXR-α, and ABCA1 in aortic and liver of atherosclerosis apoE^−/− mice were upregulated (p < 0.05, p < 0.01), while those of PI3K and Akt1 were suppressed (p < 0.05, p < 0.01). Conclusions: Citri grandis extract can significantly decrease the high circulating lipid levels and the liver lipid deposition of high-fat-diet-fed apoE^−/− mice and reduce aorta lipid accumulation and atherosclerotic plaques by regulating the expression of TGF-β1, PI3K, AKT1, PPAR-γ, LXR-α, and ABCA1. Citri grandis extract can be used as a healthcare dietary supplement for the prevention of abnormal lipid metabolism and atherosclerosis. Full article

Mesoporous silica and its derivatives might enable applications ranging from biomedicine to petrochemical processing. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and N₂ adsorption–desorption measurements are usually used to characterize the ordered porous system. However, none of these methods convey the full surface information. In this work, a low-voltage scanning electron microscope (LVSEM) with beam deceleration technology was employed to image detailed surface structures of ~2 nm pore size silica (MCM-41), SBA-15, KIT-6, and mesoporous silica nanospheres (MSNSs). The prospects for the development of this application of ultra-high-resolution scanning electron microscopy (SEM) are discussed in the characterization of the ordered porous materials. We demonstrate that the complete dimension range of the mesoscopic surface structure (2–50 nm) could be resolved by current low-voltage SEM technology. Full article

Yttrium aluminum garnet (YAG, Y₃Al₅O₁₂) fibers are promising materials for high-power lasers and high-temperature structural materials, and it is anticipated that the improvement in the stability of grain size would extend their service life at high temperatures. In this work, YAG-HfO₂ composite ceramic fibers were obtained by the solution blow spinning of YAG-HfO₂ composite precursor and sintering in steam. The effect of HfO₂ on the crystal phase transition and grain growth of YAG-HfO₂ fibers was further studied by in situ X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The results show that the HfO₂ addition increased the crystallization temperature of the YAG phase from 900 °C to 950 °C and reduced the crystal size at 1400 °C from 41.9 nm to 31.8 nm. The HfO₂ grains were distributed at the boundary of YAG grains, which enabled the fiber to maintain its dense structure and uniform grain size even at 1500 °C, exhibiting excellent high-temperature grain size stability of composite fibers. Full article

Capsaicin, a natural bioactive compound, has attracted wide interest for its potential health benefits. However, its rapid metabolism and strong irritancy upon oral administration have greatly limited its further application. To address these issues, this study developed a nanoparticle delivery system using corn Zein and Brassica rapa L. polysaccharide (BP) as carriers, with capsaicin (CAP) as the core. The optimized formulation (BP:Zein = 1:2, Zein:CAP = 2.5:1, mg/mg) produced stable, uniform spherical nanoparticles with an average particle size of 203.05 nm, a polydispersity index (PDI) of 0.138, a zeta potential of −44.9 mV, an encapsulation efficiency of 54.03%, and a drug loading capacity of 184.57 μg/mg. Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy (FS), X-Ray diffraction, scanning electron microscope (SEM), and transmission electron microscopy (TEM) analyses confirmed that CAP was successfully encapsulated, forming nanoparticles through hydrogen bonding and hydrophobic interactions between CAP and Zein. The obtained nanoparticles displayed regular spherical morphology and uniform size distribution. Compared with single-layer Zein–CAP nanoparticles, BP–Zein–Capsaicin (BZC) nanoparticles exhibited markedly improved stability under different pH, ionic strength, and storage conditions. In vitro simulated digestion showed a sustained-release profile, with 36.76% of CAP released after 4 h. The anti-inflammatory experiment showed that both the nanoparticle and free capsaicin groups significantly inhibited xylene-induced acute ear edema in mice, with the medium- and high-dose nanoparticle groups exhibiting stronger anti-inflammatory effects than the free capsaicin group. These findings suggest that the nanoparticle delivery system effectively enhances the anti-inflammatory activity of capsaicin, possibly by improving its stability, achieving sustained release, and enhancing its bioavailability in vivo. Overall, capsaicin-loaded Brassica rapa L. polysaccharide–Zein nanoparticles combine small particle size, high drug loading, and excellent stability, providing a promising strategy for functional food development and targeted bioactive delivery. Full article

Currently, the problem of climate change on Earth is becoming increasingly urgent. These changes are the reason for the increasingly pronounced adaptive differences in different species of fish. A significant gap in ultrastructural data on the organization of the salmon cerebellum was the main motivation for this study’s microscopic and ultrastructural analyses using transmission and scanning electron microscopy of the cerebellum of juvenile chum salmon Oncorhynchus keta. The study of the interneuron composition of the cerebellum showed the presence of stellate cells in the molecular layer, projection Purkinje cells, and eurydendroid cells in the ganglion layer. Large Golgi cells and granular cells were found in the granular layer. The study of the synaptic structure of the molecular layer showed the presence of synaptic contacts of electrotonic and chemical types, which are an important link in interneuronal communications. Most synaptic endings of parallel fibers of the excitatory type in juvenile chum salmon converge onto dendrites of Purkinje cells. Transmission electron microscopy (TEM) study of neuro–glial relationships also revealed a heterogeneous population of astrocytes and microglia in the cerebellum of juvenile chum salmon. Patterns of apoptosis and phagocytosis involving protoplasmic astrocytes were detected. The presence of protoplasmic astrocytes in the cerebellum of juvenile chum salmon contrasts with data reported for zebrafish. The conducted studies allow us to conclude that the homeostatic growth of the cerebellum of juvenile chum salmon can occur according to an uncertain pattern and be mediated by the presence of adult-type neural stem/progenitor cells (aNSPCs). The presence of aNSPCs of glial and non-glial types in the cerebellum of juvenile chum salmon was demonstrated by TEM and scanning electron microscopy (SEM). The discovery of a large population of non-glial aNSPCs in the dorsal matrix zone (DMZ) and granular layer of juvenile chum salmon, as well as stromal cell clusters on the surface of the cerebellar molecular layer, suggests the activity of a neurogenic program in the brain of juvenile chum salmon that is mainly active during embryonic stages in other vertebrate species. The phenomenon of embryonization in the cerebellum of juvenile chum salmon is determined by the presence of non-glial aNSPCs, which contribute to homeostatic growth. Full article

The fungus Coleosporium zanthoxyli is the causal agent of leaf rust in Chinese prickly ash pepper (Zanthoxylum armatum ‘Hanyuan putaoqing’), seriously impacting its industrial development. However, little is currently known about the infection and pathogenesis of C. zanthoxyli on Z. armatum. In this study, the infection of Z. armatum by C. zanthoxyli was reported at histological and cytological levels by a fluorescence microscope and transmission electron microscopy (TEM) for the first time. Fluorescence microscopy with fluorophore Alexa 488 (WGA-FITC) stained samples revealed that the infection process comprised three distinct stages: penetration (0–1 days post inoculation, dpi), parasitic growth (3–5 dpi), and sporulation (≥7 dpi). The number of haustoria increased during the osmotic and parasitic periods and then decreased; the length of hyphae also increased rapidly and then decreased. TEM analysis during these stages demonstrated that as disease severity increased, chloroplasts and mitochondria enlarged significantly, accompanied by a marked accumulation of starch granules and osmiophilic granules. At later stages, the nuclei became irregular, the grana lamellae were blurred, and the lamellar structure was arranged disorderly, and leaf tissues were extensively colonized by fungal hyphae and haustoria, leading to cellular necrosis and distorted cell walls. Notably, the sporulation phase was characterized by dense rust spore clusters covering the leaf surface. These findings provide critical insights into the ultrastructural changes induced by C. zanthoxyli during infection, elucidating key mechanisms of rust-induced damage in Chinese prickly ash and identifying the parasitic phase as a critical window for control strategies. This study lays a foundation for further research on rust pathogenesis and the development of Chinese prickly ash targeted control strategies. Full article

There are many obstacles to the industrial application of CO₂ hydrogenation reduction technology, the most important of which is the high economic cost. The purpose of this study is to explore the interaction mechanism between the active component CuO-ZnO-Al₂O₃(CZA) and the zeolite carrier Zeolite Socony Mobil-5(ZSM-5), screen the simplified preparation method of catalysts with high catalytic performance, and further promote the industrial application of CO₂ hydrogenation reduction technology. In this study, the effects of the gas velocity of the feedstock, the reaction temperature, the content of acidic sites in the carrier, the filling amount of active component, and the mixing mode of the active component and the carrier on catalytic CO₂ hydrogenation reduction were investigated. The structure of the catalysts was analyzed by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The catalyst surface properties were analyzed by X-ray photoelectron spectroscopy (XPS), ammonia temperature programmed desorption (NH₃-TPD), hydrogen temperature programed reduction (H₂-TPR) and other characterization methods. The research found that the grinding treatment led to the insertion of CZA between ZSM-5 zeolite particles in CZA@HZ5-20-GB, which was prepared via grinding both CZA and H-ZSM-5 with an Si/Al ratio of 20, inhibiting the action of strongly acidic sites in the zeolite, resulting in only CO and MeOH in the catalytic products, with no Dimethyl Ether (DME) generation. Full article