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31.
The equivalency equations and the nature of the solution are investigated when an inhomogeneity under applied stresses is simulated by an inclusion with eigenstrains. The equivalency equations by which the equivalent eigenstrain is obtained becomes singular when the inhomogeneity is void and the applied stress has a form of polynomials of coordinates of degree one. The solutions of the system of the equivalency equations are not uniquely determined. Explicit expressions are given for the impotent eigenstrains which do not generate any stress field throughout a material.This research was supported by the U.S. Army Research Office under Grant No. DAAG 29-77-G-0042 to Northwestern University.On leave of absence of Meiji University, Tokyo. 相似文献
32.
Miura S Nishizawa S Suzuki A Fujimoto Y Ono K Gao Q Teramae N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(50):14104-14110
A surface plasmon resonance (SPR) biosensor that carries DNA-binding small ligands has been developed for the detection of single-nucleotide polymorphisms (SNPs). 3,5-Diaminopyrazine derivatives, with a hydrogen-bonding profile fully complementary to the thymine base, were utilized as recognition elements on the sensor surface, and a target single-stranded DNA sequence was hybridized with a DNA probe containing an abasic site to place this site opposite a nucleobase to be detected. In a continuous flow of sample solutions buffered to pH 6.4 (0.25 M NaCl), the 3,5-diaminopyrazine-based SPR sensor can detect an orphan nucleobase in the duplex with a clear selectivity for thymine over cytosine, guanine, and adenine (5'-GTT GGA GCT GXG GGC GTA GGC-3'/3'-CAA CCT CGA CNC CCG CAT CCG-5'; X=abasic site, N=target nucleobase G, C, A, or T). The SPR response was linear in the concentration range 10-100 nM. Allele discrimination is possible based on the combination of different binding surfaces in a flow cell of the SPR system, which is demonstrated for the analysis of the thymine/cytosine mutation present in 63-meric polymerase chain reaction (PCR) amplification products (Ha-ras gene, codon 12, antisense strand). Comparison with a bulk assay based on 3,5-diaminopyrazine/DNA binding shows that the immobilization of 3,5-diaminopyrazine derivatives on the SPR sensor allows more sensitive detection of the target DNA sequence, and binding selectivity can be tuned by controlling the salt concentration of sample solutions. These features of the DNA-binding small-molecule-immobilized SPR sensor are discussed as a basis for the design of SPR biosensors for SNP genotyping. 相似文献
33.
Yukiko IioMakoto Yamaoka Masayoshi JinYoshitaka Nakamura Takahide Nishi 《Tetrahedron: Asymmetry》2011,22(3):323-328
Herein we report the asymmetric synthesis of α,α-disubstituted α-amino alcohol derivatives 22, 25 and 26, key intermediates of a novel immunomodulator, using Seebach’s method. This synthetic method can be applied to the large scale synthesis of chiral sphingosine 1-phosphate-1 (S1P1) receptor agonists, with significant improvements to the previously reported method with regard to the reaction temperature. 相似文献
34.
Li YX Huang MH Yamashita Y Kato A Jia YM Wang WB Fleet GW Nash RJ Yu CY 《Organic & biomolecular chemistry》2011,9(9):3405-3414
L-DMDP and L-homoDMDP, the enantiomers of naturally occurring DMDP and homoDMDP have been synthesized from D-xylose derived cyclic nitrone 9. Their 3-deoxy-3-fluorinated analogues were also obtained from polyhydroxylated fluorinated cyclic nitrone 10, which was prepared from fluorinated sugar 12 in seven steps. Bioactivities of these iminosugars against various glycosidases were evaluated. While L-DMDP and L-homoDMDP are potent inhibitors of α-glucosidases, a sharp decrease of inhibition was found when the C-3 hydroxyl group of these compounds was replaced by fluoride, which showed the great importance of the C-3 hydroxyl in their interaction with enzymes. 相似文献
35.
Matsumoto T Itakura N Nakaya Y Tatsumi K 《Chemical communications (Cambridge, England)》2011,47(3):1030-1032
A S/SH bridged hetero-dinuclear Ru/Ge complex cation reacted with H(2) to afford the μ-S/μ-H complex. The reaction was considerably slower compared to that of the μ-S/μ-OH complex. Thus, the μ-S/μ-SH and μ-S/μ-OH complexes might provide models for the unready and ready states, respectively, of [NiFe] hydrogenase. 相似文献
36.
Metal-mediated allylations of difluoroacetyltriakylsilanes with various allyl bromides in aqueous media form homoallylic alcohols exclusively. The common Brook rearrangement, carbon to oxygen-silyl migration, is totally suppressed with no detectable formation of silyl enol ether. Influence of solvents on reaction is studied. Reactivity differences between indium and zinc are also described. 相似文献
37.
Tago Teruoki Tashiro Shizuka Hashimoto Yukiko Wakabayashi Katsuhiko Kishida Masahiro 《Journal of nanoparticle research》2003,5(1-2):55-60
Silica (SiO2)-coated ceria (CeO2) nanoparticles were prepared using water-in-oil microemulsion. Polyoxyethylene (15) cetylether and cyclohexane were used as a surfactant and organic solvent. SiO2-coated CeO2 nanoparticles were obtained by hydrolysis of metal alkoxide (tetraethylorthosilicate, TEOS) in the solution containing CeO2 precursor nanoparticles. The effects of CeO2 sources (Ce metal salt) and CeO2 particle-forming agents on the morphology of SiO2–CeO2 particles were investigated. Observation via transmission electron microscopy revealed that the type of particle-forming agent affected the nanoparticles' morphology and that CeO2 nanoparticles were spherically coated with SiO2 when using oxalic acid ((COOH)2) as a particle-forming agent of CeO2. Furthermore, the transmittance of the particles was high in the visible region (above 400 nm) and decreased in the ultraviolet region. 相似文献
38.
39.
Yukio Inoue Hirokazu Hori Takeki Sakurai Yukiko Tokitomo Junko Saito Taku Misonou 《Optical Review》2002,9(2):75-80
Optical properties of an ultraviolet-absorbing substance (UVAS) extracted from the marine red alga, Porphyra yezoensis, have been investigated. The substance is excited by UV light, and the emitted fluorescence is detected using an intelligent fluorescence detector. The fluorescence of UVAS is weaker by four orders of magnitude than the fluorescence intensity emitted by anthracene in the same optical system. The absorbed energy is apparently not transferred to the photosynthesis process and is believed to be consumed as heat. Using photothermal spectroscopy, a signal is observed indicating that the absorbed photon energy has transferred to the heat. The waveform of the photothermal signal of UVAS is similar to that of quinoxaline, whose fluorescence quantum yield is known to be zero. It is determined that the fluorescence quantum yield and the energy of the triplet state of UVAS are 1.7 ± 0.7 ± 10−4 and 21000 ± 1000 cm −1, respectively. The conclusion is that the excited molecules of UVAS decay by passing through the triplet state and dissipate all absorbed energy as heat. 相似文献
40.
Masao Shiozaki Yukiko Watanabe Toshio Kaneko Daisuke Tanaka Shin-ichi Kurakata 《Tetrahedron》2005,61(21):5101-5122
Lipid A analogues containing glucose in substitution for glucosamine on the reducing end were synthesized, and the inhibitory activities on LPS-induced TNFα production (LPS-antagonistic activity) in vitro using human whole blood cells were measured. The IC50 values (nM) of these ten compounds, 8, 14, 21, 31, 40, 51, 57, 62, 67 and 72, were 11.2, 15.4, 2.7, 0.1, 0.4, 1.3, 3.2, 3.2, 1.4 and 14.4, respectively. And also inhibitory activities (ID50) on TNFα production toward galactosamine loaded C3H/HeN mice in vivo of compounds 21, 31, 57, 62 and 67 were measured. The values of these compounds were 0.29, 0.50, 0.61, not dose-dependent and 0.33 mg/kg, respectively. 相似文献