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71.
Ishibashi Chiaki Ichiyama Mai Ishida Naoya Kitamura Naoto Idemoto Yasushi 《Journal of Solid State Electrochemistry》2022,26(3):663-682
Journal of Solid State Electrochemistry - The stable structures associated with the second charge of MgCo2−xMnxO4 (x = 0, 0.5), where Mg is removed from the stable first-discharge... 相似文献
72.
Prof. Dr. Kazuhiko Semba Naoto Bessho Prof. Dr. Tetsuaki Fujihara Prof. Dr. Jun Terao Prof. Dr. Yasushi Tsuji 《Angewandte Chemie (International ed. in English)》2014,53(34):9007-9011
Borylative allyl–allyl coupling using allenes, bis(pinacolato)diboron, and allyl phosphates has been developed in the presence of a copper catalyst bearing an N‐heterocyclic carbene ligand. The reaction affords boryl‐substituted 1,5‐diene derivatives in good to high yields with high regioselectivity and Z selectivity. 相似文献
73.
An optically active α‐ethylated α,α‐disubstituted amino acid, (S)‐butylethylglycine (=(2S)‐2‐amino‐2‐ethylhexanoic acid; (S)‐Beg; (S)‐ 2 ), was prepared starting from butyl ethyl ketone ( 1 ) by the Strecker method and enzymatic kinetic resolution of the racemic amino acid. Homooligopeptides containing (S)‐Beg (up to hexapeptide) were synthesized by conventional solution methods. An ethyl ester was used for the protection at the C‐terminus, and a trifluoroacetyl group was used for the N‐terminus of the peptides. The structures of tri‐ and tetrapeptides 5 and 6 in the solid state were solved by X‐ray crystallographic analysis, and were shown to have a bent planar C5‐conformation (tripeptide) and a fully planar C5‐conformation (tetrapeptide) (see Figs. 1 and 2, resp.). The IR and 1H‐NMR spectra of hexapeptide 8 revealed that the dominant conformation in CDCl3 solution was also a fully planar C5‐conformation. These results show for the first time that the preferred conformation of homopeptides containing a chiral α‐ethylated α,α‐disubstituted amino acid is a planar C5‐conformation. 相似文献
74.
Nakayama T Kurosawa Y Furui S Kerman K Kobayashi M Rao SR Yonezawa Y Nakano K Hino A Yamamura S Takamura Y Tamiya E 《Analytical and bioanalytical chemistry》2006,386(5):1327-1333
Polymerase chain reaction (PCR) is an essential part of research based on genomics or cell analysis. The development of a
microfluidic device that would be suitable for high-temperature-based reactions therefore becomes an important contribution
towards the integration of micro-total analysis systems (μTAS). However, problems associated with the generation of air bubbles
in the microchannels before the introduction of the assay liquid, which we call the “initial start-up” in this study, made
the flow irregular and unstable. In this report, we have tried to address these problems by adapting a novel liquid-flow method
for high-temperature-based reactions. A PDMS-based microfluidic device was fabricated by soft-lithography techniques and placed
on a cartridge heater. The generation of the air bubbles was prevented by introducing the fluorinated oil, an inert and highly
viscous liquid, as the cap just before the introduction of the sample solutions into the microchannels. The technique was
applied for continuous-flow PCR, which could perform PCR on-chip in a microfluidic system. For the evaluation of practical
accuracy, plasmid DNA that serves as a reference molecule for the quantification of genetically modified (GM) maize was used
as the template DNA for continuous-flow PCR. After PCR, the products were collected in a vial and analyzed by gel electrophoresis
to confirm the accuracy of the results. Additionally, quantitative continuous-flow PCR was performed using TaqMan technology
on our PCR device. A laser detection system was also used for the quantitative PCR method. We observed a linear relationship
between the threshold cycle (Ct) and the initial DNA concentration. These results showed that it would be possible to quantify
the initial copies of the template DNA on our microfluidic device. Accurate quantitative DNA analysis in microfluidic systems
is required for the integration of PCR with μTAS, thus we anticipate that our device would have promising potential for applications
in a wide range of research. 相似文献
75.
Umezawa N 《The Journal of chemical physics》2008,128(4):044105
A simple approximation to the functional derivative of Perdew-Zunger-type self-interaction-corrected local-spin density functional is suggested. In this approach, the orbital density |phi(isigma)(r)|(2) is regarded as a functional of the local electron density |phi(isigma)(r)|(2)=n(isigma)(n(sigma)(r)) so as to enable a functional derivative of n(isigma)(n(sigma)(r)) with respect to n(sigma)(r). Our computational results show that this approximation gives fairly good estimates of the total energy, the ionization potential, and the electron affinity for atoms. Comparative studies of this method with the averaged-density approximation and the global averaging method for the self-interaction correction are made. 相似文献
76.
Naoto Ueda Takahiro Gunji Yoshimoto Abe 《Journal of Sol-Gel Science and Technology》2008,48(1-2):163-167
Linear ethoxysiloxanes were synthesized by the oxidative condensation of hydrosilane. Triethoxysilane was subjected to oxidation to form triethoxysilanol, and pentaethoxydisiloxane was formed by the condensation reaction of triethoxysilane with triethoxysilanol. Pentaethoxydisiloxane was also subjected to oxidative condensation to form a mixture of nona- and decaethoxytetrasiloxanes. In contrast, pentaethoxydisiloxane, heptaethoxytrisiloxane, and nonaethoxytetrasiloxanes were subjected to the reaction with ethanol in the presence of zinc to isolate hexaethoxydisiloxane, octaethoxytrisiloxane, and decaethoxytetrasiloxane, respectively. 相似文献
77.
78.
The asymmetric hydroformylation of 2‐ and 3‐vinylfurans ( 2a and 2b , resp.) was investigated by using [Rh{(R,S)‐binaphos}] complexes as catalysts ((R,S)‐binaphos = (11bS)‐4‐{[1R)‐2′‐phosphino[1,1′‐binaphthalen]‐2‐yl]oxy}dinaphtho[2,1‐d:1′,2′‐f][1,3,2]dioxaphosphepin; 1 ). Hydroformylation of 2 gave isoaldehydes 3 in high regio‐ and enantioselectivities (Scheme 2 and Table). Reduction of the aldehydes 3 with NaBH4 successfully afforded the corresponding alcohols 5 without loss of enantiomeric purity (Scheme 3). 相似文献
79.
[Structure: see text] Beta-isocupreidine (beta-ICD)-catalyzed Baylis-Hillman reaction of chiral N-Boc-alpha-amino aldehydes and 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) takes place without racemization and exhibits the match-mismatch relationship between the substrate and the catalyst. In the case of acyclic amino aldehydes, L-substrates show excellent syn selectivity and high reactivity in contrast to D-substrates. On the other hand, in the case of cyclic amino aldehydes, D-substrates rather than L-substrates show excellent anti selectivity and high reactivity. 相似文献
80.
Hideaki Takahashi Hajime Ohno Ryohei Kishi Masayoshi Nakano Nobuyuki Matubayasi 《Chemical physics letters》2008,456(4-6):176-180
In a recent development we proposed a quantum chemical approach to compute free energy change for chemical reactions in condensed phases by combining the QM/MM method with the theory of energy representation (QM/MM-ER). We extend in this Letter the novel approach to compute reduction free energy of isoalloxazine ring of FAD (flavin adenine dinucleotide) immersed in water within the framework of the QM/MM-ER method. The characteristic feature of our approach is that the excess electron to be attached on the FAD is identified as a solute. The reduction free energy has been obtained as −80.1 kcal/mol in the aqueous solution. 相似文献