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排序方式: 共有1372条查询结果,搜索用时 31 毫秒
1.
Shingo Urata Hiroyuki Hijiya Kazuhiko Niwano Jun Matsui 《Journal of the American Ceramic Society》2022,105(6):4200-4207
To theoretically explore amorphous materials with a sufficiently low dielectric loss, which are essential for next-generation communication devices, the applicability of a nonequilibrium molecular dynamics simulation employing an external alternating electric field was examined using alkaline silicate glass models. In this method, the dielectric loss is directly evaluated as the phase shift of the dipole moment from the applied electric field. This method enabled us to evaluate the dielectric loss in a wide frequency range from 1 GHz to 10 THz. It was observed that the dielectric loss reaches its maximum at a few THz. The simulation method was found to qualitatively reproduce the effects of alkaline content and alkaline type on the dielectric loss. Furthermore, it reasonably reproduced the effect of mixed alkalines on the dielectric loss, which was observed in our experiments on sodium and/or potassium silicate glasses. Alkaline mixing was thus found to reduce the dielectric loss. 相似文献
2.
The discovery of Lgr5+ intestinal stem cells (ISCs) triggered a breakthrough in the field of ISC research. Lgr5+ ISCs maintain the homeostasis of the intestinal epithelium in the steady state, while these cells are susceptible to epithelial damage induced by chemicals, pathogens, or irradiation. During the regeneration process of the intestinal epithelium, more quiescent +4 stem cells and short-lived transit-amplifying (TA) progenitor cells residing above Lgr5+ ISCs undergo dedifferentiation and act as stem-like cells. In addition, several recent reports have shown that a subset of terminally differentiated cells, including Paneth cells, tuft cells, or enteroendocrine cells, may also have some degree of plasticity in specific situations. The function of ISCs is maintained by the neighboring stem cell niches, which strictly regulate the key signal pathways in ISCs. In addition, various inflammatory cytokines play critical roles in intestinal regeneration and stem cell functions following epithelial injury. Here, we summarize the current understanding of ISCs and their niches, review recent findings regarding cellular plasticity and its regulatory mechanism, and discuss how inflammatory cytokines contribute to epithelial regeneration. 相似文献
3.
Dr. Chikara Dohno Prof. Kazuhiko Nakatani 《Chembiochem : a European journal of chemical biology》2019,20(23):2903-2910
We introduce the concept of molecular glues for RNA, in which specific RNA-binding small molecules induce designed structural changes in target functional RNAs, resulting in modulation of the functions. (Z)-NCTS is an RNA-mismatch-binding small molecule that recognizes 5′-r(XGG)-3′/5′-r(XGG)-3′ sequences (X=U or A) and acts as a molecular glue for RNA. The binding of (Z)-NCTS brings two distinct 5′-r(XGG)-3′ domains into contact with each other, and this can result in higher-order structural changes of target RNAs. We applied (Z)-NCTS to induce the formation of a proposed tertiary structure of a ribozyme together with activation of RNA-cleaving ability. The concept of a molecular glue could inspire new small-molecule-based strategies for regulating biological functions: a synthetic small molecule targeting functional RNAs could regulate the RNA structure and function. 相似文献
4.
Maki Toshihiro Horimoto Hiroumi Ishihara Takashi Kofuji Kazuya 《International Journal of Control, Automation and Systems》2020,18(3):597-604
International Journal of Control, Automation and Systems - This paper proposes a method for autonomous underwater vehicles to chase sea turtles without attaching any tag to them, toward efficient... 相似文献
5.
Masahiro Kaneko Kazuhiko Ishihara Shuji Nakanishi 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(34)
Microbial electrochemical systems in which metabolic electrons in living microbes have been extracted to or injected from an extracellular electrical circuit have attracted considerable attention as environmentally‐friendly energy conversion systems. Since general microbes cannot exchange electrons with extracellular solids, electron mediators are needed to connect living cells to an extracellular electrode. Although hydrophobic small molecules that can penetrate cell membranes are commonly used as electron mediators, they cannot be dissolved at high concentrations in aqueous media. The use of hydrophobic mediators in combination with small hydrophilic redox molecules can substantially increase the efficiency of the extracellular electron transfer process, but this method has side effects, in some cases, such as cytotoxicity and environmental pollution. In this Review, recently‐developed redox‐active polymers are highlighted as a new type of electron mediator that has less cytotoxicity than many conventional electron mediators. Owing to the design flexibility of polymer structures, important parameters that affect electron transport properties, such as redox potential, the balance of hydrophobicity and hydrophilicity, and electron conductivity, can be systematically regulated. 相似文献
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7.
Effects of Smart Charging of Multiple Electric Vehicles in Reducing Power Generation Fuel Cost 下载免费PDF全文
Takashi Ikegami Hitoshi Yano Koji Kudo Kazuhiko Ogimoto 《Electrical Engineering in Japan》2015,193(2):42-57
The high penetration of variable sources of renewable power generation will lead to operational difficulties in supply/demand balancing in the entire power system. The mass deployment of electric vehicles (EVs) and plug‐in hybrid vehicles (PHEVs) will also cause significant changes in electricity demand. Therefore, controlling and managing the charging time of EVs/PHEVs are effective approaches that are imperative for improving balancing in power system operation. We assumed travel patterns for EVs in a model of the future Tokyo power system and analyzed the power system loads, including the charging load of the EVs, under several charging control scenarios. We verified that charging time controls are substantially effective for reducing the fuel costs in the power system. Further, we found that load leveling under a multicar charging management scenario gave the best results in terms of the fuel costs in all cases. 相似文献
8.
Sobi Asako Takahisa Sakae Masahito Murai Kazuhiko Takai 《Advanced Synthesis \u0026amp; Catalysis》2016,358(24):3966-3970
Mild and simple catalytic systems consisting of molybdenum(VI) dichloride dioxide [MoO2Cl2] as a catalyst and a phosphine as reductant have been developed for the stereospecific deoxygenation of epoxides to alkenes. The reactions using 1,2‐bis(diphenylphosphino)ethane (dppe) and triphenylphosphine (PPh3) proceed with retention and inversion of stereochemistry, respectively. The mild reaction tolerates the presence of various functional groups and affords stereodefined substituted olefins in good yields.
9.
Renato Martins da Silva Bárbara Della Noce Camila Fernanda Waltero Evenilton Pessoa Costa Leonardo Araujo de Abreu Naftaly Wang’ombe Githaka Jorge Moraes Helga Fernandes Gomes Satoru Konnai Itabajara da Silva Vaz Jr. Kazuhiko Ohashi Carlos Logullo 《International journal of molecular sciences》2015,16(1):1821-1839
10.