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排序方式: 共有1436条查询结果,搜索用时 828 毫秒
991.
T. Ishikawa H. Fujimura H. Fukasawa R. Hashimoto Q. He Y. Honda T. Iwata S. Kaida J. Kasagi A. Kawano S. Kuwasaki K. Maeda S. Masumoto M. Miyabe F. Miyahara K. Mochizuki N. Muramatsu A. Nakamura K. Nawa S. Ogushi Y. Okada Y. Onodera K. Ozawa Y. Sakamoto M. Sato H. Shimizu H. Sugai K. Suzuki Y. Tajima S. Takahashi Y. Taniguchi Y. Tsuchikawa H. Yamazaki R. Yamazaki H. Y. Yoshida 《Few-Body Systems》2013,54(7-10):1047-1050
Baryon spectroscopy is important to understand Quantum Chromodynamics at low energies. In this purpose, a series of π 0 and η photoproduction experiments was carried out with an electro-magnetic calorimeter FOREST at Research Center for Electron Photon Science, Tohoku University. The incident tagged bremsstrahlung photon energy ranges from 550 to 1,150 MeV. The differential and total cross sections obtained for π 0 and η photoproduction processes on the proton are consistent with the SAID and MAID calculations. The analysis of π 0 and η photoproduction on the neutron is underway. 相似文献
992.
Bao‐Hua Zhu Dr. Yusuke Shibata Satoshi Muratsugu Yoshinori Yamanoi Dr. Hiroshi Nishihara Prof. 《Angewandte Chemie (International ed. in English)》2009,48(21):3858-3861
Two dragons playing ball : Direct metal–metal bond formation using a π‐conjugated dinuclear metalladithiolene complex with two electron‐deficient metal centers as building blocks led to a cyclic double trinuclear heterometalladithiolene cluster with two parallel plane bridges (see structure; Rh pink, Mo green, S yellow, C gray, O red).
993.
994.
Morizumi T Kimata N Terakita A Imamoto Y Yamashita T Shichida Y 《Photochemistry and photobiology》2009,85(1):57-62
Rhodopsin is one of the members of the G protein-coupled receptor family that can catalyze a GDP–GTP exchange reaction on the retinal G protein transducin (Gt) upon photon absorption. There are at least two intermediate states, meta-Ib and meta-II, which exhibit direct interaction with Gt. Meta-Ib binds to GDP-bound Gt, while meta-II forms a complex with Gt having no nucleotide, suggesting that meta-Ib is a state that initially interacts with Gt. Here we investigated whether or not meta-Ib exhibits specific interaction with G protein similar to meta-II, by examining the binding efficiencies of meta-Ib and meta-II to Giα and its mutants whose C-terminal 11 amino acids were replaced with those of Goα, Gqα and Gsα. The affinity of meta-Ib to the C-terminal 11 amino acids of Gtα was similar to those of Giα and its mutant with Goα's C-terminal 11 amino acids, whereas meta-II exhibited affinity to the C-terminal 11 amino acids of Giα mutant with Goα's C-terminal 11 amino acids about half of what was seen for Gtα and Giα. Both intermediates exhibited no affinity to the Giα mutants containing the C-terminal 11 amino acids of Gqα and Gsα. These results suggested that meta-Ib is the state that exhibits specific interaction with G protein as meta-II does, although meta-Ib exhibits a slightly lenient binding selectivity compared to that of meta-II. 相似文献
995.
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using a high-resolution octadecyl silica column compatible with aqueous compounds was developed for the simultaneous determination of benzodiazepines and their metabolites in human serum. This method enabled us to determine multiple benzodiazepines, including flurazepam, bromazepam, chlordiazepoxide, nitrazepam, clonazepam, flunitrazepam, estazolam, clobazam, lorazepam, alprazolam, triazolam, brotizolam, fludiazepam, diazepam, quazepam, prazepam and their metabolites such as 7-aminonitrazepam, 7-aminoclonazepam, 7-acetamidonitrazepam, N-desmethylclobazam and N-desmethyldiazepam. The analytes spiked into human serum were subjected to solid-phase extraction followed by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The running time was within 25 min for the measurement of 22 benzodiazepines and their metabolites. The recovery rates exceeded 58.1% for those compounds except for quazepam, which showed a recovery of 45.8%. The limit of detection ranged from 0.3 to 11.4 ng/mL. Linearity was satisfactory for all compounds. These data suggest that the present method can be applicable to routine assay for benzodiazepines in the clinical setting. 相似文献
996.
Takeshi Saito Toshihide Ihara Masayoshi Koike Shinichi Kinugasa Yoshinori Fujimine Kazutoshi Nose Tetsuya Hirai 《Accreditation and quality assurance》2009,14(2):79-86
Quantitative nuclear magnetic resonance (qNMR) was used for the purity determination of neat compounds of persistent organic
pollutants (POPs). qNMR is a unique quantitative method that is not only traceable to the International System of Units (SI),
but it also does not require a standard of its own. The purities of the POP compounds determined in this work were traceable
to a single certified reference material (CRM), which is extremely attractive for reference material producers. The purities
observed by qNMR were equivalent to those observed by gas chromatography with flame ionization detection (GC/FID) or a differential
scanning calorimetry (DSC) combined with a thermogravimetric analyzer (TGA). The uncertainties obtained by the qNMR method
were comparable to being slightly larger than those observed by DSC. 相似文献
997.
998.
Yoshinori Tominaga Yoshiki Matsuoka Yukio Oniyama Yoshimitsu Uchimura Hirofumi Komiya Michiyo Hirayama Shinya Kohra Akira Hosomi 《Journal of heterocyclic chemistry》1990,27(3):647-660
Polarized ethylenes having both electron-donating (an amino or a methylthio group) and electron-accepting (cyano, carbamoyl, methyl ester) groups on the adjacent two olefinic carbon atoms were prepared by the condensation of S-alkylthioamidinium salts or methyl dithiocarboxylates with the corresponding active methylene compounds in good yields. These polarized ethylenes were alternatively synthesized by the reaction of thioamides or methyl dithiocarboxylates with tetracyanoethylene oxide in good yields. Reactions of these polarized ethylenes with hydrazine or guanidine derivatives occurred smoothly to give the corresponding pyrazole and pyrimidine derivatives in good yields. The synthesis of 5-aza[2.2.3]cyclazine derivatives using polarized ethylenes is also described. 相似文献
999.
The hydroamination of alkynes using o-aminophenol proceeds in very high to good yields in the presence of Pd(NO3)2 catalyst. Remarkable rate enhancement with o-aminophenol is presumably due to the chelation effect of the ortho OH group to palladium. 相似文献
1000.
Treatment of the 1,1-diiodo-1-alkenes 8, prepared from the corresponding aldehydes with CI4/PPh3, with ZnCu/AcOH in THF-MeOH gave the (Z)-1-iodo-1-alkenes 9, selectively, in good yields. 相似文献