A Study on a Surface Preparation Method for Single-Crystal SiC Using an Fe Catalyst

In this study we investigated the possibility of removing and flattening a single-crystal silicon carbide (SiC) surface by a novel polishing method utilizing hydroxyl radicals (OH radicals) generated on an Fe catalyst surface. To demonstrate the feasibility of preparing a smooth SiC surface, an Fe catalyst and a SiC substrate were rubbed together in H₂O₂ solution, and then the area on the SiC surface that had come into contact with the Fe catalyst was observed in detail. The removal depth and surface microroughness were measured and evaluated using a phase-shift interference microscope and an atomic force microscope (AFM), respectively. Moreover, the removal of material from the SiC surface by utilizing an Fe catalyst rod was examined. The obtained results show that the hard SiC surface can be effectively polished and that the processed area on the SiC surface has atomic-level smoothness along the sliding direction. Moreover, it is shown that the removal characteristics of the SiC substrate depend on process parameters such as the process time, rotation speed, contact load, and concentration of H₂O₂ solution. These results provide useful information for preparing an atomically smooth SiC surface.     

SMTP-44D Exerts Antioxidant and Anti-Inflammatory Effects through Its Soluble Epoxide Hydrolase Inhibitory Action in Immortalized Mouse Schwann Cells upon High Glucose Treatment

Diabetic neuropathy (DN) is a major complication of diabetes mellitus. We have previously reported the efficacy of Stachybotrys microspora triprenyl phenol-44D (SMTP-44D) for DN through its potential antioxidant and anti-inflammatory activities. However, the mechanisms underlying the antioxidant and anti-inflammatory activities of SMTP-44D remain unclear. The present study aimed to explore the mechanism of these effects of SMTP-44D in regard to its inhibition of soluble epoxide hydrolase (sEH) in immortalized mouse Schwann cells (IMS32) following high glucose treatment. IMS32 cells were incubated in a high glucose medium for 48 h and then treated with SMTP-44D for 48 h. After incubation, the ratio of epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs), oxidative stress markers, such as NADPH oxidase-1 and malondialdehyde, inflammatory factors, such as the ratio of nuclear to cytosolic levels of NF-κB and the levels of IL-6, MCP-1, MMP-9, the receptor for the advanced glycation end product (RAGE), and apoptosis, were evaluated. SMTP-44D treatment considerably increased the ratio of EETs to DHETs and mitigated oxidative stress, inflammation, RAGE induction, and apoptosis after high glucose treatment. In conclusion, SMTP-44D can suppress the induction of apoptosis by exerting antioxidant and anti-inflammatory effects, possibly through sEH inhibition. SMTP-44D can be a potential therapeutic agent against DN.     

Screening for Beneficial Effects of Oral Intake of Sweet Corn by DNA Microarray Analysis

ABSTRACT: To identify novel functions of the oral intake of sweet corn, we performed DNA microarray analysis of the livers of sweet corn‐fed mice. Functional annotation clustering 1600 genes with expression levels that were affected (more than 1.5‐fold change) by dietary sweet corn indicated that both cell proliferation and programmed cell death were modulated by sweet corn intake. In the Wnt signaling pathway, which is involved in cell proliferation, the levels of Jun and β‐catenin expression were downregulated by dietary sweet corn. The mRNA levels of Rb and p53, negative regulators of the cell cycle, were increased in mice fed with sweet corn. Dietary corn upregulated expression levels of genes that regulate apoptosis positively (for example, BOK, BID, CASP4). These results suggested that sweet corn is a valuable food for suppressing cancer. Oral administration of sweet corn inhibited tumor growth (36.6% reduce in tumor weight, P < 0.05) in mice inoculated with Ehrlich tumor cells.     

Estimation on averaging effect of large‐scale aggregation of DR transient responses of building multi air‐conditioning facilities

Building‐multitype packaged air‐conditioners are expected to be possible resources of Fast Automated Demand Response (FastADR). However, transient response behaviors of each air‐conditioner are stochastic due to complicated refrigerant embedded controls. Although ensemble averaging effect is expected in aggregation of a large number of the air‐conditioners, it is difficult to carry out experiments with many actual office buildings. In this research, repetitive response time‐series data were collected from several air‐conditioners. We discuss the possibility of estimation on the ensemble averaging effects using the repetitive response data.     

Suspension pattern and rising height of sedimentary particles with low concentration in a mechanically stirred vessel

In this study, the effects of impeller rotation speed, off‐bottom clearance, blade angle, types of solid and liquid, etc., on the suspension pattern of sedimentary particles and particle rise height in liquid were investigated with a hemispherical vessel without baffles under low particle concentration. The transition conditions of suspension pattern between regimes I and II, and regimes II and III, were observed visually, and their non‐dimensional equations were expressed with an acceptable correlation by varying the above operation factors a great deal. Here, regime I is stagnation of particles on a vessel bottom, II is partial suspension, and III is complete suspension in liquid. The non‐dimensional equation of the maximum particle rise height was also successfully obtained. The combination of the non‐dimensional equations of transition and maximum particle rise height permitted us to determine the adequate solid/liquid mixing operation conditions without collision of particles with device parts.     

Synthesis-condition recommender system discovers novel inorganic oxides

Accurately predicting successful synthesis conditions to prepare new pseudo-binary oxides remains a challenge despite extensive research. This study presents a synthesis-condition recommender system to efficiently explore a wide chemistry space composed of 10 206 pseudo-binary oxide compositions. As a training dataset, we systematically performed 1542 synthesis experiments by a polymerized complex method. The results were organized into a tensor-type database. Then we scored 66 150 unexperimented synthesis conditions by the tensor-decomposition method and arranged the results in the order of increasing predicted score. We selected 300 synthesis conditions from the top predictions of unexperimented compositions and verified the predictive performance by conducting additional experiments. The fraction of successful syntheses was approximately proportional to the predicted scores, validating the synthesis-condition recommender system. Additionally, the synthesis experiments for the high-scored conditions led to the discovery of two yet-to-be-found pseudo-binary oxides: La₄V₂O₁₁ and La₇Sb₃O₁₈. La₄V₂O₁₁ and La₇Sb₃O₁₈ have similar crystal structures to γ-Bi₄V₂O₁₁ and La₇Ru₃O₁₈, respectively. The synthesis-condition recommender system gave higher predicted scores to the successful synthesis conditions of those materials.     

Fabrication and Analysis of Three-Layer All-Silicon Interference Optical Filter with Sub-Wavelength Structure toward High Performance Terahertz Optics

We propose an all-silicon multi-layer interference filter composed solely of silicon with sub-wavelength structure (SWS) in order to realize high performance optical filters operating in the THz frequency region with robustness against cryogenic thermal cycling and mechanical damage. We demonstrate fabrication of a three-layer prototype using well-established common micro-electro-mechanical systems (MEMS) technologies as a first step toward developing practical filters. The measured transmittance of the three-layer filter agrees well with the theoretical transmittances calculated by a simple thin-film calculation with effective refractive indices as well as a rigorous coupled-wave analysis simulation. We experimentally show that SWS layers can work as homogeneous thin-film interference layers with effective refractive indices even if there are multiple SWS layers in a filter.     

Synthesis of Y2O3 films on an aluminum alloy substrate using flame-spray apparatus with a H2-O2 flame

Y₂O₃ films were synthesized on an aluminum alloy (A5052) substrate directly using a flame-spray apparatus with a H₂-O₂ flame. The Y₂O₃/A5052 joining was also annealed under atmospheric conditions. Although the joining was annealed close to the melting point of the A5052 substrate, the joining showed strong adhesion without delaminations. The resultant Y₂O₃ coating exhibits a strong adhesion with the aluminum alloy substrate. Elemental diffusion in the joining was not observed from cross-sectional EDX analysis. Directly ceramic film deposition method by a reactive spraying process was proposed.     

Molecular cloning, testicular postnatal expression, and oocyte-activating potential of porcine phospholipase Czeta

The molecular mechanism by which sperm triggers Ca2+ oscillation, oocyte activation, and early embryonic development has not been clarified. Recently, oocyte activation has been shown to be induced by sperm-specific phospholipase Czeta (PLCzeta). The ability of PLCzeta to induce oocyte activation is highly conserved across vertebrates. In the present study, porcine PLCzeta cDNA was identified and the nucleotide sequence was determined. The expression pattern of porcine PLCzeta mRNA during the period of postnatal testicular development was shown to be similar to that of mouse PLCzeta. PLCzeta mRNA expression in the pig and mouse was detected only in the testes when the elongated spermatids had differentiated, and was detected from day 96 after birth in the pig. Histological examination of porcine testis during the period of postnatal development revealed the presence of spermatozoa from day 110 after birth. These findings suggest that the synthesis of PLCzeta mRNA starts when spermiogenesis is initiated. Microinjection of porcine PLCzeta complementary RNA into porcine oocytes demonstrated that porcine PLCzeta has the ability to trigger repetitive Ca2+ transients in porcine oocytes similar to that observed during fertilization. It was also found that porcine PLCzeta cRNA has the potential to induce oocyte activation and initiate embryonic development up to the blastocyst stage.