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131.
Domínguez M Alvarez R Martras S Farrés J Parés X de Lera AR 《Organic & biomolecular chemistry》2004,2(22):3368-3373
Ring-oxidized retinoids have been synthesized stereoselectively using the Stille cross-coupling reaction. Kinetic constants of mouse class I alcohol dehydrogenase (ADH1) with these retinoids were determined. 相似文献
132.
Using a mathematical framework which provides a generalization of the de Rham complex (well-designed for p-form gauge fields), we have studied the gauge structure and duality properties of theories for free gauge fields transforming in arbitrary irreducible representations of GL(D, ). We have proven a generalization of the Poincaré lemma which enables us to solve the above-mentioned problems in a systematic and unified way. 相似文献
133.
Georges Y Allenbach Y Ariza X Campagne JM Garcia J 《The Journal of organic chemistry》2004,69(21):7387-7390
Enantioenriched 4-hydroxyalk-2-ynyl carbonates (or benzoates) have been prepared by stereoselective zinc-mediated addition of alkyl 2-propynyl carbonates (or their benzoate analogues) to aldehydes. Their partial reduction to Z-olefins followed by cyclization under mild Pd-catalyzed conditions allowed a straightforward access to enantioenriched syn-1,2-diols protected as cyclic carbonates. 相似文献
134.
Cattoën X Gornitzka H Bourissou D Bertrand G 《Journal of the American Chemical Society》2004,126(5):1342-1343
Despite the presence of a single amino substituent, an amino-anthryl-carbene was found to behave as a strong sigma-donor weak pi-acceptor ligand toward rhodium(I) fragments. 相似文献
135.
Bossuyt X 《Electrophoresis》2004,25(10-11):1485-1487
Capillary zone electrophoresis (CZE) of serum proteins has become a well-accepted method for the separation of serum proteins and for the detection of monoclonal proteins in clinical laboratories. As CZE uses ultraviolet detection for direct protein quantification, exogenous ultraviolet-absorbing substances are a novel challenge, not present in conventional gel-based methods in which protein is quantified by dye binding. This minireview gives a survey of interfering substances, including iodinated contrast agents and antibiotics. 相似文献
136.
We first present a method to compute the electro-optic tensor from first principles, explicitly taking into account the electronic, ionic and piezoelectric contributions. We then study the nonlinear optic behavior of three paradigmatic ferroelectric oxides. Our calculations reveal the dominant contribution of the soft mode to the electro-optic coefficients in LiNbO3 and BaTiO3 and its minor role in PbTiO3. We identify the coupling between the electric field and the polar atomic displacements along the B-O chains as the origin of the large electro-optic response in perovskite ABO3 compounds. 相似文献
137.
138.
López C Caubet A Pérez S Solans X Font-Bardía M 《Chemical communications (Cambridge, England)》2004,(5):540-541
The synthesis of the first examples of diastereomerically pure platinacycles having simultaneously a chiral carbon and a sigma[Pt-C(sp(2), ferrocene)] bond is described. 相似文献
139.
The synthesis of the quinoline alkaloid atanine 6, by selective demethylation of the 2,4-dimethoxyquinoline 11 is presented. An alternative demethylation utilising a thiolate anion leads to the regioisomeric 4-hydroxyquinoline 13. 相似文献
140.
The trueness of an analytical method can be assessed by calculating the proportional bias of the method in terms of apparent recovery. If the apparent recovery does not differ significantly from one, the analytical method has not a significant bias. If this is the case, the bias is neglected and the uncertainty associated with this bias is included in the uncertainty budget of results. However, when assessing trueness there is always a probability of incorrectly concluding that the proportional bias is not significant. Therefore, the uncertainty of results may be underestimated. In this paper, we study how non-significant bias affects the uncertainty of analytical results. Moreover, we study how to avoid the underestimation of uncertainty by including the non-significant bias calculated in the uncertainty budget. To answer these questions, we have used the Monte-Carlo method to simulate the process of estimating the apparent recovery of a biased analytical method and, subsequently, the future results this method provides. The results of the simulation show that non-significant bias may underestimate the uncertainty of analytical results when bias contributes in more than 20% to the overall uncertainty. Uncertainty is specially underestimated when bias contributes in more than 50% to the overall uncertainty. 相似文献