Imaging Secondary-Ion Mass Spectroscopy Observation of the Scavenging of Siliceous Film from 8-mol%-Yttria-Stabilized Zirconia by the Addition of Alumina

The scavenging of a resistive siliceous phase via the addition of Al₂O₃ was studied, using imaging secondary-ion mass spectroscopy (SIMS), given the improved grain-boundary conductivity in 8-mol%-yttria-stabilized zirconia (8YSZ). The grain-boundary resistivity in 8YSZ decreased noticeably with the addition of 1 mol% of Al₂O₃. Strong SiO₂ segregation at the grain boundaries was observed in a SIMS map of pure 8YSZ that contained 120 ppm of SiO₂ (by weight). The addition of 1 mol% of Al₂O₃ caused the SiO₂ to gather around the Al₂O₃ particles. The present observations provided direct and visual evidence of SiO₂ segregation at the grain boundaries (which had a deleterious effect on grain-boundary conductivity) and the scavenging of SiO₂ via Al₂O₃ addition.     

Synthesis of C2H4 by partial oxidation of CH4 over LiCl/NiO

Alkali halide added transition metal oxides produced ethylene selectively in oxidative coupling of methane. The role of alkali halides has been investigated for LiCl-added NiO (LiCl/NiO). In the absence of LiCl the reaction over NiO produced only carbon oxides (CO₂ + CO). However, addition of LiCl drastically improved the yield of C₂ compounds (C₂H₆ + C₂H₄). One of the roles of LiCl is to inhibit the catalytic activity of the host NiO for deep oxidation of CH₄. The reaction catalyzed by the LiCl/NiO proceeds stepwise from CH₄ to C₂H₄ through C₂H₆ (2CH₄ → C₂H₆ → C₂H₄). The study on the oxidation of C₂H₆ over the LiCl/NiO showed that the oxidative dehydrogenation of C₂H₆ to C₂H₄ occurs very selectively, which is the main reason why partial oxidation of CH₄ over LiCl/NiO gives C₂H₄ quite selectively. The other role of LiCl is to prevent the host oxide (NiO) from being reduced by CH₄. The catalyst model under working conditions was suggested to be the NiO covered with molten LiCl. XPS studies suggested that the catalytically active species on the LiCl/NiO is a surface compound oxide which has higher valent nickel cations (Ni^(2+δ)+ or Ni³⁺). The catalyst was deactivated at the temperatures>973 K due to vaporization of LiCl and consumption of chlorine during reaction. The kinetic and CH₄---CD₄ exchange studies suggested that the rate-determining step of the reaction is the abstraction of H from the vibrationally excited methane by the molecular oxygen adsorbed on the surface compound oxide.     

Microfabrication of U-Shaped Grooves on the Surface of BaO–TiO2–GeO2 Glass by YAG Laser Irradiation and Selective Chemical Etching

A combination technique of Nd:YAG laser (wavelength: 1064 nm) irradiations and chemical etchings was applied to fabricate microsize U-shaped grooves on the surface of CuO-doped BaO–TiO₂–GeO₂ glass, and chemical etching behaviors were examined by using a confocal scanning laser microscope. Continuous-wave Nd:YAG lasers with a power of 0.7–0.8 W were irradiated onto the glass surface and scanned at a speed of 10 μm/s, inducing structural modified lines with refractive index changes. The chemical etching rates for the refractive index changed lines in a nitric acid solution (1 N HNO₃) were larger than those for the base glass (nonirradiated part). The etching profile was changed gradually from W-shaped to U-shaped grooves with increasing etching time. The sharp bending lines with an angle of 150° and the cross-linked lines were also smoothly etched. The U-shaped grooves with a surface covered by nonlinear optical Ba₂TiGe₂O₈ crystals were formed by the crystallization of etched samples. This study proposes that the patterning of microchannels with optical functional surfaces is possible on the glass surface using the present technique.     

Site-specific protein modification on living cells catalyzed by Sortase

The use of enzymes is a promising approach for site-specific protein modification on living cells owing to their substrate specificity. Herein we describe a general strategy for the site-specific modification of cell surface proteins with synthetic molecules by using Sortase, a transpeptidase from Staphylococcus aureus. The short peptide tag LPETGG is genetically introduced to the C terminus of the target protein, expressed on the cell surface. Subsequent addition of Sortase and an N-terminal triglycine-containing probe results in the site-specific labeling of the tagged protein. We were successful in the C-terminal-specific labeling of osteoclast differentiation factor (ODF) with a biotin- or fluorophore-containing short peptide on the living cell surface. The labeling reaction occurred efficiently in serum-containing medium, as well as serum-free medium or PBS. The labeled products were detected after incubation for 5 min. In addition, site-specific protein-protein conjugation was successfully demonstrated on a living cell surface by the Sortase-catalyzed reaction. This strategy provides a powerful tool for cell biology and cell surface engineering.     

Fracture Strength and Microstructure of β-SiAlON with Hafnia Addition

The influence of HfO₂ addition on the fracture strength and microstructure of ß-SiAlON ceramics sintered from Si₃N₄ and Al₂O₃ powders was investigated. The strength was increased by the addition of HfO₂, from ∼500 MPa to 700 MPa, and was almost constant from ambient temperature to 1300°C. Monoclinic HfO₂ grains that were distributed in the SiAlON grain boundaries had a flat shape (∼20 nm thick) and were surrounded by an amorphous phase. The aluminum concentration in ß-SiAlON in the samples with an Al₂O₃ starting composition of 15 wt% was decreased by the addition of HfO₂. The amount of secondary phases was very small at grain boundaries between the SiAlON grains; amorphous phases were observed infrequently at the triple points but were very small (∼20 nm). The effects of HfO₂ addition on the mechanism of the microstructure development and fracture strength are discussed.     

Demand forecasting for production planning in remanufacturing

The International Journal of Advanced Manufacturing Technology - Remanufacturing is effective for energy and material savings; however, production planning and control in remanufacturing are more...     

Molecular Targeted Therapy for the Bone Loss Secondary to Pyogenic Spondylodiscitis Using Medications for Osteoporosis: A Literature Review

Pyogenic spondylodiscitis can cause severe osteolytic and destructive lesions in the spine. Elderly or immunocompromised individuals are particularly susceptible to infectious diseases; specifically, infections in the spine can impair the ability of the spine to support the trunk, causing patients to be bedridden, which can also severely affect the physical condition of patients. Although treatments for osteoporosis have been well studied, treatments for bone loss secondary to infection remain to be elucidated because they have pathological manifestations that are similar to but distinct from those of osteoporosis. Recently, we encountered a patient with severely osteolytic pyogenic spondylodiscitis who was treated with romosozumab and exhibited enhanced bone formation. Romosozumab stimulated canonical Wnt/β-catenin signaling, causing robust bone formation and the inhibition of bone resorption, which exceeded the bone loss secondary to infection. Bone loss due to infections involves the suppression of osteoblastogenesis by osteoblast apoptosis, which is induced by the nuclear factor-κB and mitogen-activated protein kinase pathways, and osteoclastogenesis with the receptor activator of the nuclear factor-κB ligand-receptor combination and subsequent activation of the nuclear factor of activated T cells cytoplasmic 1 and c-Fos. In this study, we review and discuss the molecular mechanisms of bone loss secondary to infection and analyze the efficacy of the medications for osteoporosis, focusing on romosozumab, teriparatide, denosumab, and bisphosphonates, in treating this pathological condition.     

Effect of in-flight particle behavior on the morphology of flame sprayed Er2O3 splats

The morphology and microstructure of splats impact the comprehensive capability of a new coating methodology called chelate flame spraying (CFS). This study addresses the quantitative characterization of the spread morphologies of flame sprayed Er₂O₃ splats directly deposited under different spray conditions on aluminum alloy substrates with a mirror finish. The influence of the in-flight particle temperature and velocity, carrier gas type, and carrier gas ratio on the solidification mechanism of molten droplets was investigated. Image analysis methods were employed to identify single splats from the morphology observed with field-emission scanning electron microscopy (FE-SEM). In addition, Er₂O₃ films were synthesized on an Al–Mg alloy (A5052) substrate using N₂ or O₂ as the carrier gas. When O₂ was used as the carrier gas, 109-μm-thick films were deposited on the A5052 substrate. The cross-sectional porosity of the films was 3.8%. In contrast, films with 101-μm thickness were synthesized on the A5052 substrate when N₂ was used as the carrier gas. The cross-sectional porosity of these films was 13.8%. The results showed that the carrier gas type (N₂) and carrier gas ratio had a significant effect on the flattening behavior of the molten droplets. A spraying method combined with multidimensional modes is proposed to control the morphology of the splats.     

Single-crystalline silicon solar cell with pp heterojunction of c-Si substrate and μc-Si : H film

Annealing effects of the single-crystalline silicon solar cells with hydrogenated microcrystaline silicon (μc-Si : H) film were studied to improve the conversion efficiency. Boron-doped (p⁺) μc-Si : H film was deposited in a RF plasma enhanced chemical vapor deposition system (RF plasma CVD) on the rear surface of the cell. With the optimized annealing conditions for the substrate, the conversion efficiency of 21.4% (AM1.5, 25°C, 100 mW/cm²) was obtained for 5 × 5 cm² area single crystalline-solar cell.