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31.
An action spectrum for UV photocarcinogenesis 总被引:5,自引:0,他引:5
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Bailey S Davies SG Smith AD Withey JM 《Chemical communications (Cambridge, England)》2002,(23):2910-2911
The asymmetric synthesis of (1R,2S,3R)-3-methyl-2-amino-cyclopentane carboxylic acid has been achieved via kinetic resolution of racemic tert-butyl 3-methyl-cyclopentene-1-carboxylate with homochiral lithium (S)-N-benzyl-N-alpha-methylbenzylamide. 相似文献
33.
Abernethy Colin D. Baker Robert J. Cole Marcus L. Davies Aaron J. Jones Cameron 《Transition Metal Chemistry》2003,28(3):296-299
The reactivity of the carbene stabilised indium trihydride complex, [InH3(IMes)] IMes = 1,3-dimesitylimidazol-2-ylidene, toward a variety of transition metal complexes has been investigated. The study has shown that the InH3 complex can act as a carbene and/or hydride transfer reagent to transition metal centres but does not yield heterobimetallic materials. Two new complexes, [Cp2Ti(-Cl)2Zn(IMes)Cl] and [CpNi(H)(IMes)], have resulted from this work, both of which have been spectroscopically and structurally characterised. 相似文献
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John S. Davies Mark C. Eaton M. Nazar Ibrahim 《Journal of heterocyclic chemistry》1980,17(8):1813-1814
Dedicated to Professor John C. Sheehan on the occasion of his sixty-fifth birthday Nmr and glc analysis of diastereoisomeric mixtures of dipeptides has been used to study the asymmetric hydrogenation of model benzoyldidehydro- and trifluoroacetyldidehydro-dipeptide methyl esters. Chiral enhancement of one isomeric form appears to be independent of the N-terminal acyl group, but is significantly influenced by the choice of amino-acid in the C-terminal position. C-Terminal aromatic amino-acids and their derivatives give the best chiral enhancement during hydrogenation of a neighbouring dehydroamino-acid residue. 相似文献
38.
The development of solutions that prevent dehydration or promote adequate re-hydration play a vital role in preventing fatigue during exercise, however, the methods commonly used to assess the hydration ability of such solutions are invasive and often assess the components of absorption separately. This paper describes using a non-invasive deuterium tracer technique that assesses gastric emptying and intestinal absorption simultaneously to evaluate the uptake of water during rest and exercise. The kinetics of absorption are further examined by mathematical modelling of the data generated. For the rest group, 0.05 g/kg of body weight of deuterium, contained in gelatine capsules, was ingested with ordinary tap water and saliva samples were collected every 5 min for one hour while the subject remained seated. The deuterium was administered as above for the exercise group but sample collection was during one hour of exercise on a treadmill at 55% of the subject's maximum heart rate. The enrichment data for each subject were mathematically modelled and the parameters obtained were compared across groups using an independent samples t-test. Compared with the rest condition, the exercise group showed delayed absorption of water as indicated by significant differences for the modelling parameters t2, t1/2, maximum absorption rate and solution absorption amount at t1. Labelling with a deuterium tracer is a good measure of the relative rate ingested fluids are absorbed by the body. Mathematical modelling of the data generates rates of maximum absorption and allows calculation of the percentage of the solution that is absorbed at any given time during the testing period. 相似文献
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7,9-Bisdeoxycarminomycinone has been synthesised from 5-hydroxyquinizarin by two annelation routes involving nitronate addition to C-2 and aldol condensation at C-3. 4-Demethoxy-7,9-bisdeoxydaunomycinone has been synthesised efficiently by similar methods. 相似文献