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481.
482.
Sensitive detection of glycyrrhizin and evaluation of the affinity constants by a surface plasmon resonance-based immunosensor. 总被引:1,自引:0,他引:1
Takatoshi Sakai Katsura Shinahara Akira Torimaru Hiroyuki Tanaka Yukihiro Shoyama Kiyoshi Matsumoto 《Analytical sciences》2004,20(2):279-283
A sensitive and selective determination of glycyrrhizin (GC) based on surface plasmon resonance (SPR) was performed by using an anti-GC monoclonal antibody (GC-MAb) and GC-bovine serum albumin (GC-BSA) conjugate (antigen). GC-BSA was immobilized on an Au thin film of the SPR sensor chip by physical adsorption, and GC determinations were performed by an indirect competitive method. The addition of GC into the GC-MAb solution (5 microg/ml) was found to decrease the incident-angle shift sharply because of an inhibition effect of GC. The RSDs (n = 3) of each point were less than 4%. The lowest detection limit for GC by SPR was almost the same as that by ELISA, 60-75 ng/ml. An evaluation of the affinity constant between GC-MAb and GC using the data from ELISA and those from SPR measurements was performed. The values of the association constant (KA) from three different analyses of ELISA data and from SPR measurements are discussed in detail. As a whole, the affinity constant (KA) between GC-MAb and GC was on the order of 10(7) M(-1). 相似文献
483.
Hiroyoshi Kamogawa Katsumasa Kawashima Manabu Shimizu Yukihiro Sakakibara 《Liquid crystals》1991,10(1):101-110
Aryl carboxylic esters bearing disubstituted pyridine rings were synthesized starting with various pyridine mono- or dicarboxylic acids by means of reactions, principally, with phenolic compounds. Some of the pyridine monocarboxylates thus synthesized exhibited clear nematic phases at relatively low temperatures, whereas most of the 2,5-pyridine dicarboxylates bearing two benzene rings provided nematic phases, the ranges of which were some times wider and/or lower than those of the corresponding aryl esters bearing benzene rings alone. 相似文献
484.
"Magic mushrooms" (MMs) are psychoactive fungi containing the and Psychotropics Control Law in Japan. Because there are many kinds of MMs and they are often sold even as dry powders in local markets, it is very difficult to identify the original species of the MMs by morphological observation. Therefore, we investigated the rRNA gene for a large subunit (LSU) of several MMs to classify them by a genetic approach. In this paper, we described the phylogeny of species of MMs based on the partial sequence (about 970 bp) of the LSU and the rapid identification of MMs using the TaqMan PCR assay. 相似文献
485.
486.
This paper describes highly sensitive HPLC methods for the determination of amphetamine (AP) and methamphetamine (MP) in abusers' plasma and hair samples. AP and MP were derivatized with the fluorescent reagent, DIB-Cl, to yield a highly fluorescent DIB-derivatives of AP and MP, which were then analyzed by HPLC with fluorescence detection at excitation and emission wavelengths of 325 and 430 nm, respectively. The separation was achieved on an ODS column with isocratic mobile phases composed of acetoniltrile and citrate buffer (55:45, v/v) for plasma samples and of acetonitrile-methanol-citrate buffer (45:20:37.5, v/v/v) for hair samples. The limits of detection were less than 0.87 ng/mL and 0.12 ng/mg in plasma and hair samples, respectively, for both AP and MP. The methods were then applied to the determination of MP and its metabolite AP in plasma obtained from two cases of illegally ingested MP and in one of the cases' hair received later. Case I was treated with dialysis; samples before and after dialysis were analyzed by the described method. After dialysis for 5 h, the total plasma levels of AP and MP decreased from 720 to 190 ng/mL. For case II, MP and AP levels were monitored for 3 days after digestion. Total plasma levels decreased from 57 ng/mL in the day of digestion to 11 ng/mL after 3 days. In hair samples, AP and MP could also be detected in very low concentrations. 相似文献
487.
488.
The reaction of 2,5-dimethoxypyrazines with iodotrimethylsilane followed by hydrolysis was investigated to prepare the title compounds. 相似文献
489.
Kikuo Harigaya Atsushi Yamashiro Yukihiro Shimoi Katsunori Wakabayashi 《Current Applied Physics》2004,4(6):587-590
We theoretically study the electronic states in graphene ribbons which are strongly affected by the edge states, the peculiar non-bonding molecular orbitals localized along the zigzag edges of the ribbons. New kinds of edge localized electronic states with spin and charge polarizations are found in the mean field solutions of the extended Hubbard model with onsite and nearest-neighbor Coulomb repulsions. These novel states appear due to the interplay between the edge states and the Fermi instabilities. We also examine the competition between the charge polarized state and the spin polarized state to draw a phase diagram depending on Coulomb parameters. The results obtained by the mean field calculations with the extended Hubbard model modified to include Coulomb integrals provide useful insights to understand and functionalize the nanoscale materials. 相似文献
490.
The diffraction patterns of a square aperture having third-order coma are obtained using holographic aberration. These patterns agree fairly well with the contour lines obtained numerically by Barakat and Houston. 相似文献