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Moumita Paira 《Tetrahedron letters》2007,48(18):3205-3207
A simple and efficient methodology has been developed for the one-pot preparation of α-methylene-γ-butyrolactones by free-radical induced Barbier-type reaction of methyl 2-(bromomethyl)acrylate and aldehydes followed by in situ lactonization. The radical initiator titanocene(III) chloride (Cp2TiCl) was easily generated in situ from commercially available Cp2TiCl2 and activated zinc dust in THF. Ketones remained unaffected under the reaction conditions. 相似文献
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Baylis-Hillman adduct underwent smooth radical-induced condensation with activated bromo compounds and epoxides using titanocene(III) chloride (Cp2TiCl) as the radical generator. The reactions of activated bromo compounds with 3-acetoxy-2-methylene alkanoates provided (E)-alkenes exclusively, whereas similar reactions with 3-acetoxy-2-methylenealkanenitriles led to (Z)-alkenes as the major product. The reactions of epoxides with Baylis-Hillman adduct furnished alpha-methylene/arylidene-delta-lactones in good yield via addition followed by in situ lactonization. 相似文献
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Moumita Maiti 《Journal of Radioanalytical and Nuclear Chemistry》2013,297(3):319-329
Use of reactor produced radionuclides is popular in life sciences. However, cyclotron production of proton rich radionuclides are being more focused in recent times. These radionuclides have already gained attention in various fields, including life sciences, provided they are obtained in pure form. This article is a representative brief of our contributions in generating nuclear data for the production of proton rich radionuclides of terbium, astatine, technetium, ruthenium, cadmium, niobium, zirconium, rhenium, etc., which may have application in clinical, biological, agriculture studies or in basic research. The chemical data required to separate the product isotopes from the corresponding target matrix have been presented along with a few propositions of radiopharmaceuticals. It also emphasizes on the development of simple empirical technique, based on the nuclear reaction model analysis, to generate reliable nuclear data for the estimation of yield and angular distribution of emitted neutrons and light charged particles from light as well as heavy ion induced reactions on thick stopping targets. These data bear utmost important in radiation dosimetry. 相似文献
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Moumita Maiti Susanta Lahiri B. S. Tomar 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(2):427-432
149Gd was produced from the 12C induced reaction on natural praseodymium target. No-carrier-added (nca) 149Gd was separated from the bulk target matrix by liquid–liquid extraction (LLX) using cation exchanger di-(2-ethylhexyl)phosphoric
acid (HDEHP) dissolved in cyclohexane. High separation factor of 2,450 was achieved at the optimal experimental condition
when 1% HDEHP and 0.1 M HCl were used as organic and aqueous phases respectively. The result was also compared with the previous
reports. 相似文献
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The determination of the sequence selectivity of DNA-damaging agents is very important in elucidating the mechanism of action of anti-tumour drugs. The development of automated capillary DNA sequencers with fluorescent labelling has enabled a more precise method for DNA sequence specificity analysis. In this work we utilized the ABI 3730 capillary sequencer with laser-induced fluorescence to examine the sequence selectivity of cisplatin with purified DNA sequences. The use of this automated machine enabled a higher degree of precision of both position and intensity of cisplatin-DNA adducts than previously possible with manual and automated slab gel procedures. A problem with artefact bands was overcome by ethanol precipitation. It was found that cisplatin strongly formed adducts with telomeric DNA sequences. 相似文献
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Amongst various radionuclides of molybdenum, 90Mo and 99Mo have suitable β energy for clinical uses. In this paper we report separation of 99Mo from 99Mo-99mTc equilibrium mixture. The liquid–liquid extraction technique has been employed using trioctylamine (TOA) diluted in cyclohexane
as organic phase and HCl as aqueous phase. At 10−5 M HCl and 0.5 M TOA concentration 99mTc quantitatively transferred to the organic phase leaving 99Mo in the aqueous phase. The developed separation method is efficient and provides very high separation factor. 相似文献