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131.
A cationic Ir(I)-tolBINAP complex catalyzed an enantioselective C-C bond formation initiated by secondary sp(3) C-H bond cleavage adjacent to a nitrogen atom. The reaction of 2-(alkylamino)pyridines with various alkenes gave chiral amines in good yields with high enantiomeric excesses. 相似文献
132.
The chemoselective Pd-catalyzed Suzuki-Miyaura cross-coupling reaction using a diborylmethane is reported. The use of an equimolar amount of base with a diborylmethane realized chemoselective coupling for the synthesis of various benzylboronate derivatives. Sterically hindered aryl bromides can give products in moderate to excellent yields. 相似文献
133.
In the present study, we synthesized dextran (MW = ca. 2,000 kDa)-based macromolecular probes containing multiple molecules
of alkaline phosphatase (ALP) as a signal-trigger enzyme and of biotin as an assembly mediator. The ALP and biotin molecules
were covalently attached into the dextran backbone after the formation of aldehyde groups into the macromolecule by periodate
oxidation. The synthesized probes contained 27–31 molecules of ALP in their macromolecules when 50-fold molar ratio of ALP
to the dextran was used for the synthesis. These probes provided 14–20 times stronger chemiluminescence (CL) than that of
the equimolar free ALP adsorbed on a nylon membrane. The velocity of the CL reaction of ALP-catalyzed adamantlyl-1,2-dioxetane
substrate was improved from a slower emission (glow type) of CL to a faster one (flash type). The CL signal integrated for
2 min under strongly alkaline conditions (pH 13.0) was about ten times greater than that obtained by the conventional conditions
(pH 9.5). Therefore, the synthesized macromolecular probe could be successfully utilized for the high-throughput CL detection
of biotin-conjugated anti-rabbit IgG antibody with a lower detection limit of 880 amol per spot on the nylon membrane. This
study provides analytical strategy for the rapid, convenient, and sensitive detection of target proteins in immunoassays. 相似文献
134.
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136.
Velocity and metastable state population distributions of neodymium atoms produced by laser ablation
H. Wang H. Ohba M. Saeki M. Miyabe T. Shibata H. Miyatake H. Iimura 《Applied physics. B, Lasers and optics》2005,81(8):1127-1133
Laser-induced fluorescence spectroscopy has been employed to characterize the plume produced in nanosecond laser ablation
of metallic neodymium. The kinetic-energy distributions of the neutral and ionized atoms in the plume under both vacuum and
gas environments have been investigated. The population distribution of metastable levels in the ablated atoms was also derived.
The results show that some metastable states are more heavily populated than predicted by a Boltzmann-type distribution. These
investigations provide preliminary data for the design of a new type of resonance photo-ionization laser ion source as well
as for high-resolution laser spectroscopy of refractory elements.
PACS 52.38.Mf; 33.50.Dq; 42.62.Fi 相似文献
137.
J G Hu H Tanimori M Shibata T Yokoyama T Kitagawa 《Chemical & pharmaceutical bulletin》1989,37(5):1316-1320
Highly sensitive and accurate enzyme immunoassays (EIAs), a sandwich EIA for mouse immunoglobulin G (IgG) and an enzyme linked immunosorbent assay for mouse antibody specific to viomycin (VM), were developed. Accuracy and specificity of the assay results were confirmed before their application. The changes of total IgG and antibody specific to VM in mice, immunized with a VM-immunogen with or without two types of Freund's adjuvants under various conditions, were assessed by means of the newly developed EIA methods. Both methods were very useful tools to follow the immunization processes of mice, and complete and incomplete Freund's adjuvant were found to have similar adjuvant activities for production of antibody specific to VM, judging from the amounts of anti-VM antibody formed. It seems to be important that too many booster injections should be avoided in the immunization of mice with a hapten immunogen. 相似文献
138.
Iridium-chiral diphosphine complex catalyzes an enantioselective intramolecular Pauson-Khand-type reaction to give various chiral bicyclic cyclopentenones. The enantioselective reaction proceeds more smoothly and enantioselectively under a lower partial pressure of carbon monoxide. Moreover, aldehyde can be used as a CO source in the enantioselective carbonylative coupling. 相似文献
139.
140.