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101.
The insertion reaction of isocyanide into a C-S bond of dithioacetals is catalyzed by GaCl3 or TiCl4 to afford thioimidates containing an alpha-alkylthio group. Balanced thiophilicity of these Lewis acids is critical for efficient catalysis. 相似文献
102.
Shimada Y Goto T Kawamoto S Kiso T Katayama A Yamanaka Y Aki T Chiang KC Nakano T Goto S Chen CL Ohmori N Ono K Sato S 《Biomedical chromatography : BMC》2008,22(1):13-19
In organ transplantation, the development of a novel immunosuppressant free of the need for permanent administration and any serious side effects has eagerly been awaited. We have previously reported that an anti-histone H1 polyclonal antibody has immunosuppressant activity. Here we prepared an anti-histone H1 monoclonal antibody as an analytical tool to elucidate its mechanism of immunosuppression. The isotype of this monoclonal antibody was immunoglobulin M. A monoclonal antibody prepared for administration to organ transplantation model animals should not contain any allogenic proteins and should have high purity. Therefore, we conducted a two-step chromatography procedure, consisting of strong anion-exchange chromatography and gel filtration chromatography, to purify an anti-histone H1 monoclonal immunoglobulin M antibody from the serum-free culture supernatant of hybridomas. Consequently, we successfully purified the monoclonal antibody at 96%, a purification rate at which its administration to organ transplantation model animals is possible. 相似文献
103.
Naoyuki Kotoku Aoi Ito Shunichi Shibuya Kanako Mizuno Aki Takeshima Masaki Nogata Motomasa Kobayashi 《Tetrahedron》2017,73(10):1342-1349
An improved method for synthesizing structurally simplified analogs of cortistatin A (1), a novel anti-angiogenic steroidal alkaloid from a marine sponge, was developed. In contrast to previous methods, step- and redox-economical synthesis was achieved using a known α-bromoketone as the starting material. The structure-activity relationship study revealed that the isoquinoline portion was strictly recognized by the target molecule. Surprisingly, the introduction of the acetamide moiety on the A-ring structure dramatically enhanced the selective antiproliferative activity against endothelial cells. This new method can be easily applied to gram-scale synthesis and enabled us to prepare various analogs, which were focused on the participation of the side chain and A-ring structure. 相似文献
104.
7-Acylaminocephalosporanic acid derivatives (1) were converted into 7-acylamino-3-methylenecepham-4-carboxylic acids (2) by treatment with chromium(II) salts in aqueous media. The esters (4a or 4b) of 7-acylamino-3-methylenecepham compounds were readily isomerized to the 3-methyl-3-cephem compounds (5a or 5b) under basic conditions. The reaction mechanism is discussed. 相似文献
105.
106.
107.
Sueli M. Tanaka Aki Sandra M.S. de Godoy 《Nonlinear Analysis: Real World Applications》2009,10(1):172-184
The paper studies a class of a system of linear retarded differential difference equations with several parameters. It presents some sufficient conditions under which no stability changes for an equilibrium point occurs. Application of these results is given. 相似文献
108.
H. Aki T. Niiya Y. Iwase M. Yamamoto 《Journal of Thermal Analysis and Calorimetry》2001,64(2):713-719
Two different types (structures) of inclusion complexes with a 1:1 stoichiometry between barbiturates and 2-hydroxypropyl-β-cyclodextrin
(HPCyD) were realized in aqueous solution using isothermal titration calorimetry and molecular dynamics simulation. The first
type of complex with a higher association constant was entropy driven and the substituent R
2 was inserted into the HPCyD cavity by hydrophobic interaction. The barbituric acid ring contributed to the second type of
complex, which was characterized by large negative values of ΔH and small positive ΔS reflecting van der Waals interaction and/or hydrogen bonding formation between the hetero atoms in the barbituric acid ring
and the secondary hydroxyl groups of HPCyD.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
109.
In considering mathematics problem solving as a model-eliciting activity (
[Lesh and Doerr, 2003],
[Lesh and Harel, 2003] and [Lesh and Zawojewski, 2008]), it is important to know what students are modeling for the problems: situations or solutions. This study investigated Grade 3 students’ mathematization process by examining how they modeled different types of multi-digit subtraction situation problems. Students’ modeling processes differed from one problem type to another due to their prior experiences and the complexity of the problems. This study showed that students make their own distinctions between solution and situation models in their mathematization process. Mathematics curricula and teaching should consider these distinctions to carefully facilitate different model development of and support student understanding of a content topic. 相似文献
110.
In this paper, we review the mass probes used for the derivation of a variety of biomolecules efficiently detected by the electrospray ionization-mass spectrometry and mass probe-assisted ionization method for total analysis and determination by consecutive detection with a single instrument. We describe mass probes for a variety of molecules including proteins, nucleobases, metallic cations, and other small molecules. 相似文献