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81.
Kadota I Takamura H Sato K Ohno A Matsuda K Yamamoto Y 《Journal of the American Chemical Society》2003,125(1):46-47
The convergent total synthesis of gambierol (1) is described. The octacyclic ether framework of 1 was constructed via the intramolecular allylation of alpha-chloroacetoxy ether followed by ring-closing metathesis. A modified Stille coupling was successfully applied to the synthesis of the triene side chain. 相似文献
82.
Dioxin-like polychlorinated biphenyls (DL-PCBs) often make up the majority of the toxic equivalent (TEQ) contribution of dioxins found in fish samples. For the purpose of making risk assessments, it is therefore important to develop screening methods for determining TEQ concentrations of DL-PCBs in retail fish. We have developed a rapid biosensor immunoassay (BIA) for DL-PCBs that uses a surface plasmon resonance sensor (Biacore 3000). The BIA is highly specific for 2,3',4,4',5-pentachlorobiphenyl (PCB 118) that is generally the most abundant DL-PCB isomer found in fish. The fish extracts were first cleaned up on a multilayer silica gel column followed by an alumina column, then subjected to the assay. The quantitative limit of the assay was 1 ng PCB 118 per gram of tested sample. Dilution and recovery tests using purified fish extracts suggested that the matrix effect was minimized in the assay by diluting the analyzed samples. The assay results for retail fish samples (n=7) agreed well with those obtained by an enzyme-linked immunoassay (ELISA) using the same monoclonal antibody: ELISA has been already validated for determining DL-PCBs in fish samples, so BIA performs well in this analysis. Finally, BIA results for the TEQ concentrations of DL-PCBs in retail fish samples (n=10) correlated well with those obtained by high-resolution gas chromatography coupled to high-resolution mass spectrometry (r=0.89). Our method is therefore useful for screening retail fish to determine the TEQ concentrations of DL-PCBs. 相似文献
83.
Nami Choi Kumiko Asano Sakura Watanabe Wataru Ando 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):379-380
1,3-Bis[tris(trimethylsilyl)methyl]-2,4,5-trichalcogena-1,3-disilabicyclo[1.1.1]pentanes display unusual short bridgehead Si---Si distances despite the absence of formal Si—Si bonds, and chalcogen---chalcogen interactions are observed by nmr, X-ray analysis and electronic spectroscopy. 相似文献
84.
Omori A Ichinose S Kitajima S Shimotohno KW Murashima YL Shimotohno K Seto-Ohshima A 《Electrophoresis》2002,23(24):4167-4174
The distribution of proteins in the cerebral cortex of a seizure-sensitive (SS) strain of gerbil and its seizure-resistant (SR) counterpart was profiled using two-dimensional gel electrophoresis. A series of proteins of similar molecular weight (around 83 kDa) showed small but consistent differences in their isoelectric point (pI) with indistinguishable profiles of distribution between the two strains. Amino acid sequences of peptides produced by limited proteolysis of each protein in the spots from the strains were identical or highly homologous to those of mitofilin, a mitochondrial inner membrane protein (IMMT) in humans. Analysis of cDNA sequences revealed the proteins of these spots to be gerbil mitofilin-like proteins (gIMMT), with a few base substitutions between SS and SR strains, in particular within a region near a putative transmembrane domain that is highly conserved in humans and gerbils. The amino acid at the site was acidic, Glu in humans and Asp in the strain SR of gerbil and a neutral, Asn in strain SS. In addition to these base substitutions, production of multiple species of mRNA for gIMMT by alternative splicing was observed. 相似文献
85.
Kumiko Nishioka 《Monatshefte für Mathematik》1997,123(2):135-148
Algebraic independence of the numbers
, where{R
n
}
n
0 is a sequence of integers satisfying a binary linear recurrence relation, is studied by Mahler's method. 相似文献
86.
The optical and electrical characteristics of heterojunction organic photovoltaic cells consisting of tin–phthalocyanine as a p-type semiconductor and fullerene as an n-type semiconductor were studied using multiple-layer structures incorporating two hetero-junctions. In order to prevent formation of a reverse heterojunction, an ultra-thin layer of Au clusters was set between dual heterojunctions. The power conversion efficiencies of the cells were evaluated and the efficiency of the cell with two incorporated heterojunctions was found to be 4.5 times greater than that of a single hetero-junction. By using surface plasmon polaritons, the power conversion efficiency of an Al/C⋐70/SnPc/Au cell was enhanced and increased by a factor of 3. 相似文献
87.
88.
Ajima K Yudasaka M Maigné A Miyawaki J Iijima S 《The journal of physical chemistry. B》2006,110(11):5773-5778
We incorporated cisplatin inside single-wall carbon nanohorns (NHs) and revealed that 70% of the cisplatin was released from NHs having holes with hydrogen-terminated edges when they were immersed in phosphate-buffered saline (PBS). However, only 15% was released from NHs having holes with oxygen-containing functional groups at the hole edges (NHox). Elemental analysis indicated that -COOH and -OH groups at the hole edges of NHox changed mainly to -COONa and -ONa groups by immersion in PBS. These groups decreased the practical hole diameters, which resulted in hindering the cisplatin release from NHox. This means that the release of the material from inside NHox would be controlled by chemically modifying the functional groups attached to the hole edges of NHox; thus the potential applicability of NHox to a material carrier would be enhanced. 相似文献
89.
Kitagaki S Katoh K Ohdachi K Takahashi Y Shibata D Mukai C 《The Journal of organic chemistry》2006,71(18):6908-6914
Intermolecular [4 + 2] cycloaddition of o-quinodimethanes, prepared in situ from ene-bis(propargyl alcohols) and benzenesulfenyl chloride via ene-bis(sulfinylallene) formation, was investigated. Benzene-bridged bis(propargyl alcohols) reacted with both electron-deficient and electron-rich olefins to give the corresponding [4 + 2] cycloadducts. Ethylene-bridged bis(propargyl alcohols) underwent similar cycloaddition with electron-deficient olefins. Construction of some heterocycles based on the newly developed sequential reaction is also described. 相似文献
90.
Tsuchiya T Sato K Kurihara H Wakahara T Nakahodo T Maeda Y Akasaka T Ohkubo K Fukuzumi S Kato T Mizorogi N Kobayashi K Nagase S 《Journal of the American Chemical Society》2006,128(20):6699-6703
Complexation of endohedral metallofullerene La@C(82)-A (1) with macrocyclic compounds, such as 1,4,7,10,13,16-hexaazacyclooctadecane (2), 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane (3), mono-aza-18-crown-6 ether (4), 18-crown-6 ether (5), and p-tert-butylcalix[n]arenes (n = 4-8, 6-10), for the first time is examined. Among them, 1 forms a complex with azacrown ethers 2-4 while accompanying the electron transfer between them. This is characteristic of endohedral metallofullerene and caused by its low reduction potential. Activation energies, DeltaG(et), for the electron transfer from 2-4 to 1 are 4.6, 2.8, and 11 kcal/mol, respectively. These small DeltaG(et) values indicate that the electron transfer from the azacrown ethers to 1 is facile in the ground state. Furthermore, the selective isolation of lanthanum endohedral metallofullerenes from the extracts of soot is accomplished by utilizing the complexation of 1 with 2. 相似文献