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排序方式: 共有640条查询结果,搜索用时 718 毫秒
631.
Membrane reactor immobilized with palladium‐loaded polymer nanogel for continuous‐flow Suzuki coupling reaction
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Hirokazu Seto Tamami Yoneda Takato Morii Yu Hoshino Yoshiko Miura Tatsuya Murakami 《American Institute of Chemical Engineers》2015,61(2):582-589
A catalytic membrane reactor, which was immobilized with palladium‐loaded nanogel particles (NPs), was developed for continuous‐flow Suzuki coupling reaction. Palladium‐loaded membranes were prepared by immobilization of NPs, adsorption of palladium ions, and reduction into palladium(0). The presence of palladium in the membrane was confirmed by the scanning electron microscopy; palladium aggregation was not observed. The catalytic activity of the membrane reactor in continuous‐flow Suzuki coupling reaction was approximately double that of a comparable reactor in which palladium ions were directly adsorbed onto an aminated membrane. This was attributed to the formation of small palladium particles. The reusability in the continuous‐flow system was higher than that in a batch system, and the palladium‐loaded membrane reactor had high long‐term stability. © 2014 American Institute of Chemical Engineers AIChE J, 61: 582–589, 2015 相似文献
632.
Novel Mechanism of Fatty Acid Sensing in Enteroendocrine Cells: Specific Structures in Oxo‐Fatty Acids Produced by Gut Bacteria Are Responsible for CCK Secretion in STC‐1 Cells via GPR40
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633.
Anatase titanium dioxide (TiO2) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO2 pellets as the source material. Highly transparent TiO2 thin films prepared at substrate temperatures from room temperature to 400 °C exhibited photocatalytic activity, regardless whether oxygen (O2) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO2 thin films prepared at 300 °C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO2 thin film with a resistivity of 2.6 × 10− 1 Ω cm was prepared at a substrate temperature of 400 °C without the introduction of O2 gas. 相似文献
634.
Taira Matsuo Rie Komori Minami Nakatani Shiori Ochi Aya Yokota-Nakatsuma Junichi Matsumoto Fuyuko Takata Shinya Dohgu Yasuhiro Ishihara Kouichi Itoh 《International journal of molecular sciences》2022,23(14)
Acute brain inflammation after status epilepticus (SE) is involved in blood–brain barrier (BBB) dysfunction and brain edema, which cause the development of post-SE symptomatic epilepsy. Using pilocarpine-induced SE mice, we previously reported that treatment with levetiracetam (LEV) after SE suppresses increased expression levels of proinflammatory mediators during epileptogenesis and prevents the development of spontaneous recurrent seizures. However, it remains unclear how LEV suppresses neuroinflammation after SE. In this study, we demonstrated that LEV suppressed the infiltration of CD11b+CD45high cells into the brain after SE. CD11b+CD45high cells appeared in the hippocampus between 1 and 4 days after SE and contained Ly6G+Ly6C+ and Ly6G−Ly6C+ cells. Ly6G+Ly6C+ cells expressed higher levels of proinflammatory cytokines such as IL-1β and TNFα suggesting that these cells were inflammatory neutrophils. Depletion of peripheral Ly6G+Ly6C+ cells prior to SE by anti-Ly6G antibody (NIMP-R14) treatment completely suppressed the infiltration of Ly6G+Ly6C+ cells into the brain. Proteome analysis revealed the downregulation of a variety of inflammatory cytokines, which exhibited increased expression in the post-SE hippocampus. These results suggest that Ly6G+Ly6C+ neutrophils are involved in the induction of acute brain inflammation after SE. The proteome expression profile of the hippocampus treated with LEV after SE was similar to that after NIMP-R14 treatment. Therefore, LEV may prevent acute brain inflammation after SE by suppressing inflammatory neutrophil infiltration. 相似文献
635.
Previous studies demonstrated that Syk protein-tyrosine kinase (Syk) is activated by thrombin in platelets. To elucidate the function of Syk in platelets, we have biochemically examined the intracellular location of Syk and the molecules associated with Syk, following platelet activation. In human platelets, thrombin induces the relocation of Syk to the cytoskeletal fraction presumably via Syk tyrosine phosphorylation. Relocated Syk is associated with the actin filament network, and the early phase (10-90 s) of this association can be partially inhibited by the pretreatment of platelets with cytochalasin D, an inhibitor of actin polymerization. Upon thrombin stimulation, Syk becomes associated with Fak as demonstrated by co-immunoprecipitation. The association of both kinases can be inhibited by pretreatment of platelets with cytochalasin D. Interestingly, reconstitution experiments, using COS cells transfected with various porcine Syk mutants, revealed that the kinase domain, but not the kinase activity, of Syk is required for the association of Syk with the actin filament network. These findings suggest that thrombin-induced association of Syk with Fak correlates with the state of actin polymerization, and may play an important role in platelet activation. 相似文献
636.
Ichiro Minami 《Lubrication Science》1995,7(4):319-331
The addition of more antioxidant to aged oils is not always effective in preventing autoxidation. To investigate this phenomenon, a solution of antioxidant and model oxide in hexadecane was examined by means of the induction period method. Aldehydes were found to be the most active species for reducing the antioxidation properties of zinc dialkyldithiophosphate (ZDTP), 2,6-di(tert. butyl)-4-methylphenol (DBPC), and N-phenyl-1-naphtylamine (PNA). Carboxylic acids, ethers, alcohols, and ketones to some extent reduced the induction period with these antioxidants. Esters showed almost no influence on reducing their antioxidant properties. Reaction of ZDTP with aldehyde was studied by means of 31P-NMR analysis. It was found that (a) aldehydes accelerate conversion of ZDTP, and thereby reduce its antioxidant performance. (b) Conversion of ZDTP in the presence of aldehydes under oxygen at 130° in hexadecane and no reaction was observed under nitrogen at the same temperature. Active intermediates derived by the autoxidation of aldehyde were suspected. (c) Reaction of peroxycarboxylic acid with ZDTP took place smoothly at 0°C under nitrogen to give bis(dialkylthiorophosphoro)disulphide and the corresponding carboxylic acid. Reaction of hydroperoxide with ZDTP took place at room temperature to give oxo-hexa(dialkylphosphorothiorothionato)-tetrazinc. Two mechanisms for decomposition of ZDTP promoted by aldehydes, namely hydroperoxide and peroxycarboxylic acid mechanisms, are proposed. Reaction of peroxycarboxylic acid with DBPC or PNA barely took place at room temperature: for these antioxidants, the peroxycarboxylic acid mechanism would be excluded. Radical species derived by the autoxidation of aldehydes were considered as active intermediates. It is considered that classification of the types of oxides that exist in used oils in the key to optimising the effect of re-added antioxidants. 相似文献
637.
Artificial Life and Robotics - With the spread of COVID-19, the need for remote detection of physical conditions is increasing, for example, there are several situations wherein the body... 相似文献
638.
In recent years, the introduction of photovoltaic power generation systems has been increasing from the perspective of global warming countermeasures. However, there is a problem that it becomes difficult to adjust the supply and demand balance of electric power. Therefore, in this research, the inverter by using estimation signal estimates the load of the consumer, then we aim to adjust the supply-demand balance at the demand side. By the verification of experimental, three-phase inverter, which is assumed to be an industrial photovoltaic power generation system, estimates the load by using pseudo random binary sequence (PRBS) signal and two proposed methods. The load estimation results show that the error rate of the estimated resistance of each phase is within a few percent by using the two proposed methods, and the load estimation is achieved. 相似文献
639.
Effect of small additions of Li2O on phase separation and crystallization of barium-silicate glasses
Takato Kajihara Kosho Akatsuka Hiroyuki Hijiya Satoshi Yoshida Aran Mitsuta Hongye Gao Shigeru Fujino Satoshi Hata 《Journal of the American Ceramic Society》2023,106(7):4181-4191
It is known that the addition of Li2O to 33.3BaO-66.7SiO2 glass, whose composition is the same as BaSi2O5, promotes crystallization of BaSi2O5. In this study, in order to clarify the effect of a smaller amount of Li2O, xLi2O-(30-x)BaO-70SiO2[mol%] (x = 0, 0.2, 0.5) glasses were prepared. The main crystalline phases in the heat treatments near the maximum crystallization peak temperature, were high-BaSi2O5 and low-BaSi2O5 which transformed from high-BaSi2O5. It is found that the introduction of only 0.2 mol% and 0.5 mol% Li2O significantly changes the crystallization behavior. In the composition without Li2O, only high-BaSi2O5 was formed after heat treatment even for 24 h. For compositions containing Li2O, low-BaSi2O5 was formed within 1 h of heat treatment. In these compositions, it is found that the addition of Li2O enhances phase separation in the early stage of heat treatment, resulting in the formation of Si-rich droplet phases and Ba-rich phases. The composition of the Ba rich glass phase would be close to the stoichiometric composition of BaSi2O5, suggesting a significant change in crystallization behavior. 相似文献
640.
Recently, energy harvesting has attracted increasing attention. The present study focuses on vibration generators based on piezoelectric elements by proposing an internal capacitor cancel control (ICCC) rectifier to improve the output power. The proposed rectifier cancels the internal capacitor to improve the output power while retaining the maximum output power. Accordingly, this paper experimentally demonstrates the improvement in output power by using the ICCC rectifier compared to conventional circuits and the previous proposed circuit. 相似文献