Driving mechanism, design, fabrication process, and experiments of a cylindrical ultrasonic linear microactuator

A new type of cylindrical ultrasonic linear microactuator (CULMA) is introduced. The traveling wave generation condition in the stator is presented, which was confirmed using simulation and experimentation. The design and fabrication process to develop the stator is described. The stator was successfully fabricated using metallic glass and a sputtering method, and the vibration of the prototype matched the simulation results. When the driving frequency is at 626 kHz, the traveling wave in the stator was observed. Loaded with a pipe slider, the slider movement was experimentally demonstrated and the motion measured with 26 mm/s in peak speed. This paper presents a traveling wave generation method in a CULMA which would also available in other microactuators or MEMS-scale ones.     

Molecular Basis of Bile Acid-FXR-FGF15/19 Signaling Axis

Bile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver. The FXR/RXRα heterodimer also exists in the distal ileum and regulates production of fibroblast growth factor (FGF) 15/FGF19, a hormone traveling via the enterohepatic circulation that activates hepatic FGF receptor 4 (FGFR4)-β-klotho receptor complex and regulates gene expression involved in cholesterol, BA, and lipid metabolism, as well as those regulating cell proliferation. Agonists for FXR and analogs for FGF15/19 are currently recognized as a promising therapeutic target for metabolic syndrome and cholestatic diseases.     

γH2AX,a DNA Double-Strand Break Marker,Correlates with PD-L1 Expression in Smoking-Related Lung Adenocarcinoma

In recent years, the choice of immune checkpoint inhibitors (ICIs) as a treatment based on high expression of programmed death-ligand 1 (PD-L1) in lung cancers has been increasing in prevalence. The high expression of PD-L1 could be a predictor of ICI efficacy as well as high tumor mutation burden (TMB), which is determined using next-generation sequencing (NGS). However, a great deal of effort is required to perform NGS to determine TMB. The present study focused on γH2AX, a double-strand DNA break marker, and the suspected positive relation between TMB and γH2AX was investigated. We assessed the possibility of γH2AX being an alternative marker of TMB or PD-L1. One hundred formalin-fixed, paraffin-embedded specimens of lung cancer were examined. All of the patients in the study received thoracic surgery, having been diagnosed with lung adenocarcinoma or squamous cell carcinoma. The expressions of γH2AX and PD-L1 (clone: SP142) were evaluated immunohistochemically. Other immunohistochemical indicators, p53 and Ki-67, were also used to estimate the relationships of γH2AX. Positive relationships between γH2AX and PD-L1 were proven, especially in lung adenocarcinoma. Tobacco consumption was associated with higher expression of γH2AX, PD-L1, Ki-67, and p53. In conclusion, the immunoexpression of γH2AX could be a predictor for the adaptation of ICIs as well of as PD-L1 and TMB.     

Soy-Derived Equol Induces Antioxidant Activity in Zebrafish in an Nrf2-Independent Manner

Antioxidant effects of soy-derived isoflavones are predicted to be mediated by the Keap1-Nrf2 pathway. Recently, we constructed an assay system to evaluate the antioxidant effects of dietary phytochemicals in zebrafish and revealed a relationship between these effects and the Keap1-Nrf2 pathway. In this study, we used this system to examine the antioxidant effects of seven isoflavones. Among those seven, equol showed strong antioxidant effects when arsenite was used as an oxidative stressor. The antioxidant effect of equol was also shown in Nrf2-mutant zebrafish nfe2l2a^fh318, suggesting that this effect was not mediated by the Keap1-Nrf2 pathway. To elucidate this unidentified mechanism, the gene expression profiles of equol-treated larvae were analyzed using RNA-seq and qRT-PCR, while no noticeable changes were detected in the expression of genes related to antioxidant effects, except weak induction of Nrf2 target genes. Because nfe2l2a^fh318 is an amino acid-substitution mutant (Arg485Lue), we considered that the antioxidant effect of equol in this mutant might be due to residual Nrf2 activity. To examine this possibility, we generated an Nrf2-knockout zebrafish nfe2l2a^it321 using CRISPR-Cas9 and analyzed the antioxidant effect of equol. As a result, equol showed strong antioxidant effects even in Nrf2-knockout larvae, suggesting that equol indeed upregulates antioxidant activity in zebrafish in an Nrf2-independent manner.     

Study on field demonstration of high‐sensitivity SF6 leakage detection method for gas insulated switchgear

SF6 gas is widely used in power equipment such as gas insulated switchgear or gas circuit breaker. However, its global warming potential is 23,500 times higher than that of CO₂. In consideration of environmental protection, detection of SF6 gas leakage with high sensitivity is necessary. The authors proposed an algorithm to accurately estimate the average gas temperature from the tank surface temperature for establishing a high‐sensitive SF6 slow leak detection technology. Since the gas temperature depends on the temperature of the conductor, the algorithm was characterized by estimating the gas temperature from the tank surface temperature and the load current. The relationship among the tank surface temperature, the gas temperature, and the current was preliminarily investigated by the use of the thermal fluid analysis and stored in the database. By use of this method, the fluctuation of the converted pressure in the basic examination test was suppressed to 20% as compared with that without considering the current. In addition, database was also created from the machine learning of field test result in substitution. In the field test, it was confirmed that the detection time of 0.5%/year slow leak could be detected in about 8 months by considering the load current.     

承受高压及轴向应变的高性能输气管线用钢管的开发和性能分析(中)

近50年来,天然气的消耗量大大增加,并且会继续增加以降低主要能源的CO2排放量。随着天然气供应量的增加,为保证其输送的经济性和安全性,开发了高强度大直径焊管,并已成功应用在全球多个地区（如北极地区、地震带和深海海域）。天然气需求的增加对长距离输送管线用钢管提出了新的要求,为此,研究了更为恶劣环境下承受高压和轴向应变的高性能钢管：分析了所开发的高压输气管线用高品质钢管的性能;探讨了承受轴向应变钢管的进一步开发。     

Foundation of logic programming based on inductive definition

A logical system of inference rules intended to give the foundation of logic programs is presented. The distinguished point of the approach taken here is the application of the theory of inductive definitions, which allows us to uniformly treat various kinds of induction schema and also allows us to regardnegation as failure as a kind of induction schema. This approach corresponds to the so-called least fixpoint semantics. Moreover, in our formalism, logic programs are extended so that a condition of a clause may be any first-order formula. This makes it possible to write a quantified specification as a logic program. It also makes the class of induction schemata much larger to include the usual course-of-values inductions.     

Thin film deposition of Cu2O and application for solar cells

Deposition conditions of cuprous oxide (Cu₂O) thin films on glass substrates and nitrogen doping into Cu₂O were studied by using reactive radio-frequency magnetron sputtering method. The effects of defect passivation by crown-ether cyanide treatment, which simply involves immersion in KCN solutions containing 18-crown-6 followed by rinse, were also studied. By the crown-ether cyanide treatment, the luminescence intensity due to the near-band-edge emission of Cu₂O at around 680 nm was enhanced, and the hole density was increased from 10¹⁶ to 10¹⁷ cm⁻³. Finally, polycrystalline p-Cu₂O/n-ZnO heterojunctions were grown for use in solar cells. Two deposition sequences were studied, ZnO deposited on Cu₂O and Cu₂O deposited on ZnO. It was found that the crystallographic orientation and current–voltage characteristics of the heterojunction were significantly influenced by the deposition sequence, both being far superior for the heterojunction with structure Cu₂O on ZnO than for the inverse structure. We successfully obtained a photoresponse for the first time in the deposited thin film of Cu₂O/ZnO.     

MICRO-CRACK GROWTH AND LIFE PREDICTION OF A 1CrMoV STEEL UNDER AXIAL-TORSIONAL LOW CYCLE FATIGUE AT 550°C

Abstract— Micro-crack behaviour under axial and torsional loading at 550°C was observed by replica techniques. Cracking behaviour and micro-damage observations were correlated using several parameters that are based on equivalent strain parameters. From the observations, micro-cracking of the oxide films at the crack tip in the strain localized regions seems to be a dominant micromechanism of fatigue crack growth. The maximum principal strain has been identified as an important parameter in multiaxial fatigue at high temperature. A good correlation was obtained between the principal strain range and the crack growth rate. Finally, a life prediction method was proposed based on maximum crack length.