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排序方式: 共有893条查询结果,搜索用时 15 毫秒
71.
Dr. Naoki Umezawa Yuhei Horai Dr. Yuki Imamura Makoto Kawakubo Mariko Nakahira Dr. Nobuki Kato Akira Muramatsu Prof. Dr. Yuko Yoshikawa Prof. Dr. Kenichi Yoshikawa Prof. Dr. Tsunehiko Higuchi 《Chembiochem : a European journal of chemical biology》2015,16(12):1811-1819
A versatile solid‐phase approach based on peptide chemistry was used to construct four classes of structurally diverse polyamines with modified backbones: linear, partially constrained, branched, and cyclic. Their effects on DNA duplex stability and structure were examined. The polyamines showed distinct activities, thus highlighting the importance of polyamine backbone structure. Interestingly, the rank order of polyamine ability for DNA compaction was different to that for their effects on circular dichroism and melting temperature, thus indicating that these polyamines have distinct effects on secondary and higher‐order structures of DNA. 相似文献
72.
Takahiro Mise Shin Tajima Tatsuo Fukano Kazuo Higuchi Tsukasa Washio Kazuo Jimbo Hironori Katagiri 《Progress in Photovoltaics: Research and Applications》2016,24(7):1009-1015
We have investigated the influence of sodium (Na) on the properties of co‐evaporated Cu2ZnSnS4 (CZTS) layer microstructures and solar cells. The photovoltaic performance and diode properties were improved by incorporating Na from NaF layers into the CZTS layers, while Na had a negligible effect on the microstructural properties of the layer. The best cell fabricated by using an optimal CZTS layer (Cu/(Zn + Sn) = 0.70, Zn/Sn = 1.8) yielded an active area efficiency of 5.23%. The analysis of device properties suggests that charge‐carrier recombination at CZTS/CdS interface is suppressed by intentional Na incorporation from NaF layers. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
73.
Akihiko Wakai Keizo Ugai Atsuo Onoue Seiichiro Kuroda Kunihiro Higuchi 《Soils and Foundations》2010,50(4):533-545
The damage caused by an earthquake-induced landslide can generally be classified as either a limited deformation or a catastrophic failure. From an engineering point of view, the latter can be much more dangerous because the sliding mass may continue moving until it collides with another object. If a catastrophic failure occurs near a river, the debris may block the river, causing serious damage to the adjacent area. Therefore, examination of the mechanism of such catastrophic slope failures is important with respect to the mitigation of earthquake disasters in mountainous districts, although numerical modeling of such phenomena is rather difficult. In the present study, a new numerical model is developed to simulate an earthquake-induced catastrophic landslide that occured at a typical dip slope, namely, the Yokowatashi Landslide in Japan. In this case, the upper part of the bedrock on the planer tectonic dip surface slid more than 70 m. Only shear-strength degradation at the bedding plane could cause such a long-distance traveling failure. To investigate the strain-softening characteristics of the materials that filled the bedding plane, a series of laboratory tests involving undisturbed block samples was performed. The measured stress-displacement relationships under cyclic loading were numerically modeled as a newly proposed elasto-plastic constitutive model to be used in numerical simulations of landslide, based on the dynamic finite element method. The observed phenomena were appropriately simulated by the proposed method. The mechanism of catastrophic failure is discussed in detail in this paper in order to clarify the relationships between the strain-softening characteristics and the global slope stability. Our newly proposed method to evaluate the possibility of a catastrophic failure was applied to the landslide, and the moment when the slope becomes unstable was able to be predicted. The results confirm that the proposed method can predict the catastrophic failure of a slope. 相似文献
74.
Yoshikatsu Higuchi Masayuki Sugawara Koji Onishi Masatomi Sakamoto Susumu Nakayama 《Ceramics International》2010
Electrical properties of LaxM6O12+1.5x (M = Si, Ge) as an electrolyte for solid oxide fuel cell (SOFC) have been investigated. In LaxSi6O12+1.5x and LaxGe6O12+1.5x of x = 8–11, the highest conductivities were achieved at x = 9.7 (La9.7Si6O26.55) and x = 9.0 (La9.0(GeO4)6O1.5), respectively. The conductivity of La9.0(GeO4)6O1.5 was higher than that of La9.7Si6O26.55 in a temperature region higher than 700 °C, and the conductivity (2.4 × 10−3 S cm−1) of La9.7Si6O26.55 at 400 °C was higher than that (8.3 × 10−5 S cm−1) of La9.0(GeO4)6O1.5. The power densities of SOFC (H2 | Pt | electrolyte (thickness: 1 mm) | Pt | O2) using La9.0(GeO4)6O1.5 as an electrolyte were 14.3 mW cm−2 (700 °C) and 24.0 mW cm−2 (800 °C). The corresponding SOFC using La9.7Si6O26.55 was found to work even at lower temperatures of 400 and 500 °C with power densities of 0.011 and 0.12 mW cm−2. The SOFC (H2 | Ni–Sm0.2Ce0.8O1.9 | electrolyte | Ba0.5Sr0.5Co0.8Fe0.2O2.5 | air) using 0.3 mm thickness La9.7Si6O26.55 electrolyte gave the 3.4 mW cm−2 power density at 500 °C. 相似文献
75.
Molecular biology of oxygen tolerance in lactic acid bacteria: Functions of NADH oxidases and Dpr in oxidative stress 总被引:2,自引:0,他引:2
Lactic acid bacteria including Streptococcus mutans lack cytochromes and heme-containing proteins. Most lactic acid bacteria also lack catalase. However, they can grow in the presence of air. In view of the defense against oxygen toxicity, the lack of catalase in lactic acid bacteria is not always consistent with its aerotolerance. Mechanisms, by which lactic acid bacteria establish their growth in air, are therefore an active area of investigation. We identified two kinds of NADH oxidase genes, nox-1 and nox-2 for H2O2-forming NADH oxidase (Nox-1) and H2O-forming NADH oxidase (Nox-2), respectively, in S. mutans and found that Nox-1 is homologous with flavoprotein component, AhpF, of Salmonella typhimurium alkyl hydroperoxide reductase (AhpR), consisting of AhpF and AhpC. We also identified ahpC which is homologous with ahpC of S. typhimurium, upstream of nox-1 in S. mutans. In the first and second parts of this article, we will refer to the role of Nox-1 which acts together with AhpC as bi-component peroxidase system in S. mutans, catalyzing the NADH-dependent reduction of organic hydroperoxides or H2O2 to their respective alcohol and/or H2O. We will also refer to the role of Nox-2 in carbohydrate metabolism of S. mutans in its aerobic life. Nox-2 was found to be involved in regenerating NAD+, which is required for glycolysis in S. mutans. While studying nox-1 and ahpC double deletion mutant of S. mutans, we found that the mutant still showed the same level peroxide tolerance as did the wild-type strain. The finding suggested the existence of another antioxidant system in addition of Nox-1 and AhpC in S. mutans. We identified a new gene, dpr (for Dps-like Peroxide Resistance gene) and its product, Dpr, as an iron-binding protein which is responsible for oxygen tolerance in S. mutans. In the third part of this article, we will refer to the current status of knowledge of molecular cloning of dpr, the characteristics of dpr-disruption mutants, and a mechanism by which Dpr confers aerotolerance to S. mutans. 相似文献
76.
Higuchi M Miyata D Kawamura S Ueda E Imanaka M Tonogai Y 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(6):339-343
Daily intakes of 12 phenols which are possible endocrine disruptors were estimated in hospital meals from 2000 to 2001. 4-Nonylphenol (4-NP (mix)) and bisphenol A (BPA) were detected at levels of 5.0 to 19.4 ng/g and 0.2 to 1.1 ng/g, respectively. 4-tert-Butylphenol, 4-n-pentylphenol, 4 -tert-pentylphenol, 4-n-hexylphenol, 4-n-heptylphenol and 4-tert-octylphenol were detected at levels of 0.1 to 2.4 microg/g. The daily intakes of 4-NP (mix) and BPA were 5.8 microg/day and 0.42 microg/day, respectively. The daily intakes of other phenols were less than 1 microg/day. 相似文献
77.
78.
Ryota Nakahar Kazuma Sekiguchi Kenichiro Nonak Masahiro Takasugi Hiroki Hasebe Kenichi Matsubara 《控制理论与应用(英文版)》2022,20(2):248-262
When heavy-duty commercial vehicles (HDCVs) must engage in emergency braking, uncertain conditions such as the brakepressure and road profile variations will inevitably affect braking control. To minimize these uncertainties, we propose acombined longitudinal and lateral controller method based on stochastic model predictive control (SMPC) that is achieved viaChebyshev–Cantelli inequality. In our method, SMPC calculates braking control inputs based on a finite time prediction thatis achieved by solving stochastic programming elements, including chance constraints. To accomplish this, SMPC explicitlydescribes the probabilistic uncertainties to be used when designing a robust control strategy. The main contribution of thispaper is the proposal of a braking control formulation that is robust against probabilistic friction circle uncertainty effects.More specifically, the use of Chebyshev–Cantelli inequality suppresses road profile influences, which have characteristicsthat are different from the Gaussian distribution, thereby improving both braking robustness and control performance againststatistical disturbances.Additionally, since theKalman filtering (KF) algorithm is used to obtain the expectation and covarianceused for calculating deterministic transformed chance constraints, the SMPC is reformulated as a KF embedded deterministicMPC. Herein, the effectiveness of our proposed method is verified via a MATLAB/Simulink and TruckSim co-simulation. 相似文献
79.
Christian Gentzsch Dr. Matthias Hoffmann Dr. Yasuhiro Ohshima Naoko Nose Dr. Xinyu Chen Prof. Dr. Takahiro Higuchi Prof. Dr. Michael Decker 《ChemMedChem》2021,16(9):1427-1437
The enzyme butyrylcholinesterase (BChE) represents a promising target for imaging probes to potentially enable early diagnosis of neurodegenerative diseases like Alzheimer's disease (AD) and to monitor disease progression in some forms of cancer. In this study, we present the design, facile synthesis, in vitro and preliminary ex vivo and in vivo evaluation of a morpholine-based, selective inhibitor of human BChE as a positron emission tomography (PET) tracer with a pseudo-irreversible binding mode. We demonstrate a novel protecting group strategy for 18F radiolabeling of carbamate precursors and show that the inhibitory potency as well as kinetic properties of our unlabeled reference compound were retained in comparison to the parent compound. In particular, the prolonged duration of enzyme inhibition of such a morpholinocarbamate motivated us to design a PET tracer, possibly enabling a precise mapping of BChE distribution. 相似文献
80.
Kento Nishida Hiroshi Watanabe Ryota Murata Kai Tokumaru Rui Fujimura Shun Oshiro Taisei Nagasaki Masako Miyahisa Yuto Hiramoto Hiroto Nosaki Tadashi Imafuku Hitoshi Maeda Masafumi Fukagawa Toru Maruyama 《International journal of molecular sciences》2021,22(11)
An effective strategy is highly desirable for preventing acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Thioredoxin-1 (Trx), a redox-active protein that has anti-oxidative and anti-inflammatory properties, would be a candidate for this but its short half-life limits its clinical application. In this study, we examined the renoprotective effect of long-acting Trx that is comprised of human albumin and Trx (HSA-Trx) against AKI to CKD transition. AKI to CKD mice were created by renal ischemia-reperfusion (IR). From day 1 to day 14 after renal IR, the recovery of renal function was accelerated by HSA-Trx administration. On day 14, HSA-Trx reduced renal fibrosis compared with PBS treatment. At the early phase of fibrogenesis (day 7), HSA-Trx treatment suppressed renal oxidative stress, pro-inflammatory cytokine production and macrophage infiltration, thus ameliorating tubular injury and fibrosis. In addition, HSA-Trx treatment inhibited G2/M cell cycle arrest and apoptosis in renal tubular cells. While renal Trx protein levels were decreased after renal IR, the levels were recovered by HSA-Trx treatment. Together, HSA-Trx has potential for use in the treatment of AKI to CKD transition via its effects of modulating oxidative stress and inflammation. 相似文献