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11.
Suga M Nishiyama H Konyuba Y Iwamatsu S Watanabe Y Yoshiura C Ueda T Sato C 《Ultramicroscopy》2011,111(12):1650-1658
Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields. 相似文献
12.
Improvement of lysozyme recovery method from the precipitate of protein-anionic surfactant complexes
Takumi Kinugasa Kanako Okabe Kenta Jinno Kiyohito Uchida Yasuhiro Nishii 《分离科学与技术》2017,52(18):2918-2925
A new protein separation process using a surfactant and a polar organic solvent consists of a precipitation step and a recovery step. In the precipitation step, a protein-surfactant complex is precipitated from an aqueous solution, when an ionic surfactant, sodium di(2-ethylhexyl) sulfosuccinate (AOT), is added to an aqueous solution, including protein (lysozyme). In the recovery step, the precipitate is dissolved in a polar organic solvent, such as acetone, and the protein is recovered as precipitates when a very small amount of salt solution was added to remove surfactants from the protein-surfactant complex. However, the details of the protein recovery step from precipitate have not been studied yet. In this study, the improvement of the protein recovery step was examined from the viewpoint of a recovery ratio of protein and a remaining ratio of surfactant. The optimum NaCl concentration in the feed for the protein recovery was in the range of 0.05–0.2 kmol/m3. As the NaCl concentration in the feed increased to more than 0.2 kmol/m3, the precipitation ratio decreased due to the electrostatic screening effect of NaCl. It was found that the addition of a very small amount of NaCl solution to acetone was unnecessary when NaCl was included in the feed lysozyme solution. On the other hand, as the NaCl concentration decreased to less than 0.05 kmol/m3, the precipitation ratio was decreased due to the low re-precipitation of protein by the addition of a small amount of NaCl solution in acetone. In the case of the feed containing no salt, the desired NaCl concentration added to acetone was in the range above 0.2 kmol/m3. In addition, the most suitable volume ratio of acetone to feed was found to be 0.2. 相似文献
13.
Dr. Masanobu Nagano Takumi Oguro Ryo Sawada Dr. Toru Yoshitomi Prof. Keitaro Yoshimoto 《Chembiochem : a European journal of chemical biology》2021,22(23):3341-3347
Dysregulation of tumor necrosis factor-α (TNFα), a pro-inflammatory cytokine, causes several diseases, making it an important therapeutic target. Here, we identified a novel DNA aptamer against human TNFα using in vitro selection, which included a high exclusion pressure process against non-binding and weak binders through microbead-assisted capillary electrophoresis (MACE) in only three rounds. Among the 15 most enriched aptamers, Apt14 exhibited the highest inhibitory activity for the interaction between TNFα and its cognate receptor in mouse L929 cells. For further improving the bioactivity of the aptamer, dimerization programed by hybridization was evaluated, resulting in the Apt14 dimer exhibited a twofold higher binding affinity and stronger inhibition compared to the monomer counterpart. Rapid identification of bioactive aptamers using MACE in combination with facile dimerization by hybridization accelerates the discovery of novel bioactive aptamers, paving the way toward replacing current monoclonal antibody therapy with the less expensive and non-immunogenic aptamer therapy. 相似文献
14.
Hidemine Obara Masamu Kamaga Takumi Ito Yukihiko Sato 《Electrical Engineering in Japan》2014,186(4):81-91
Multilevel converters can essentially reduce harmonics even when their switching frequency is low. Among the various topologies of the multilevel converters, flying capacitor converters are considered to be promising converters for realizing high power density. However, the main circuit of the flying capacitor converters has many capacitors. Therefore, in this study, the volume of the capacitors in the flying capacitor converters is determined by taking into consideration the allowable ripple voltage and temperature rise in the capacitor. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 81–91, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22361 相似文献
15.
Koizumi Hiroyasu Morio Naoki Ishikawa Alto Kondo Takumi 《Journal of Superconductivity and Novel Magnetism》2022,35(9):2357-2370
Journal of Superconductivity and Novel Magnetism - We theoretically study the superconductivity in hole-doped cuprate superconductors by employing a model composed of surface and bulk CuO $$_2$$... 相似文献
16.
Satoshi Fujiwara Takamasa Imada Tomoya Nakagita Shinji Okada Takashi Nammoku Keiko Abe Takumi Misaka 《Food chemistry》2012,130(3):561-568
Sweet enhancing effect of neohesperidin dihydrochalcone (NHDC) or cyclamate has been reported to be synergistic in human sensory tests. However, little is known about whether these synergisms are caused by the mechanism mediated by the human sweet-taste receptor. Here, we examined the sweetness intensity of sweet tastant mixtures by measuring the responses of cultured cells stably expressing the human sweet-taste receptor. The results showed that the cell response to sucrose was synergistically potentiated by the addition of NHDC or cyclamate. Moreover, a point mutation in the transmembrane domain of hT1R3 almost completely eliminated the enhancing effects of NHDC and cyclamate. These results suggest that ligand–receptor interactions in the transmembrane domain of hT1R3 are necessary for NHDC and cyclamate to elicit the synergistic potentiation of the receptor activation. Our results may provide the foundation of a molecular basis for receptor-based synergisms of sweet tastes in mixtures of diverse sweet substances. 相似文献
17.
Phase Relations and Volume Changes of Hafnia under High Pressure and High Temperature 总被引:1,自引:0,他引:1
Osamu Ohtaka Hiroshi Fukui Taichi Kunisada Tomoyuki Fujisawa Kenichi Funakoshi Wataru Utsumi Tetsuo Irifune Koji Kuroda Takumi Kikegawa 《Journal of the American Ceramic Society》2001,84(6):1369-1373
Using multi-anvil high-pressure devices and synchrotron radiation, X-ray in situ observations of HfO2 under high pressure and high temperature have been performed to investigate its phase relations and compression behavior. An orthorhombic phase (orthoI) is stable from 4 to 14.5 GPa below 1250°–1400°C and transforms to a tetragonal phase, which is one of the high-temperature forms of HfO2 , above these temperatures. Another orthorhombic phase (orthoII) with a cotunnite-type structure appears above 14.5 GPa. OrthoII is stable up to 1800°C at 21 GPa. OrthoII is quenchable to ambient conditions. The orthoI-to-orthoII transition is accompanied by ∼8 vol% decrease. The bulk moduli of orthoI and orthoII at room temperature are 220 and 312 GPa, respectively. This low compressibility of orthoII indicates that it is a potential candidate for very hard materials. 相似文献
18.
Syntheses of Spinon Thermal Conductivity Materials in Sr–Cu–O System by Glass‐Ceramics Technique 下载免费PDF全文
Nobuaki Terakado Yuudai Yokochi Kouki Watanabe Yoshihiro Takahashi Takumi Fujiwara 《Journal of the American Ceramic Society》2016,99(5):1565-1572
We have synthesized spinon thermal conductivity materials in Sr–Cu–O system by glass‐ceramics technique. The materials are promising for active control of thermal energy in microelectronic devices because of high and anisotropic thermal conduction, its controllability, and electric insulation. Nevertheless, research on these materials has been limited to that concerning theoretical perspectives and investigation of physical properties using large single crystals. In this study, we adopt glass‐ceramics technique to synthesize these materials: We prepared melt‐quenched multicomponent oxides including SrO and CuO, and checked its glass‐forming ability and crystallization behaviors by heating. As a result, we have found that SrCuO2 and Sr14Cu24O41, known as the spinon thermal conductivity materials, are synthesized using SrO–CuO–?Li2O–?Al2O3?–Ga2O3 system. This synthesis process for the system will provide practical application of the spinon thermal conductivity materials. 相似文献
19.
Joao Gari da Silva Fonseca Junior Takashi Oozeki Hideaki Ohtake Takumi Takashima Kazuhiko Ogimoto 《Progress in Photovoltaics: Research and Applications》2015,23(10):1203-1218
The development of methods to forecast photovoltaic (PV) power generation regionally is of utmost importance to support the spread of such power systems in current power grids. The objective of this study is to propose and to evaluate methods to forecast regional PV power 1 day ahead of time and to compare their performances. Four forecast methods were regarded, of which two are new ones proposed in this study. Together, they characterize a set of forecast methods that can be applied in different scenarios regarding availability of data and infrastructure to make the forecasts. The forecast methods were based on the use of support vector regression and weather prediction data. Evaluations were performed for 1 year of hourly forecasts using data of 273 PV systems installed in two adjacent regions in Japan, Kanto, and Chubu. The results show the importance of selecting the proper forecast method regarding the region characteristics. For Chubu, the region with a variety of weather conditions, the forecast methods based on single systems' forecasts and the one based on stratified sampling provided the best results. In this case, the best annual normalized root mean square error (RMSE) and mean absolute error (MAE) were 0.25 and 0.15 kWh/kWhavg, respectively. For Kanto, with homogeneous weather conditions, the four methods performed similarly. In this case, the lowest annual forecast errors were 0.33 kWh/kWhavg for the normalized RMSE and 0.202 kWh/kWhavg for the normalized MAE. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
20.
Yuki Tanaka Takumi Sako Tatsuhiro Hiraoka Misaki Yamaguchi Masayuki Yamaguchi 《应用聚合物科学杂志》2020,137(46):49516
The structure and rheological properties of binary blends of polycarbonate (PC) and polystyrene (PS) were investigated using various PS samples with different molecular weights, namely PS1k (Mw = 1,000), PS53k (Mw = 53,000), and PS240k (Mw = 240,000). The blends with PS53k and PS240k show phase-separated structures, whereas the blend with PS1k is miscible. The shear viscosity decreases greatly on addition of PS53k and PS240k, especially at high shear rates, which would be a great advantage at processing operations. Because the nonlinear response occurs in the small strain region for multilayered films of PC and PS240k, the origin of the significant viscosity drop for the phase-separated system is interfacial slippage at the phase boundary. 相似文献