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111.
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Shin Y Fournier JH Brückner A Madiraju C Balachandran R Raccor BS Edler MC Hamel E Sikorski RP Vogt A Day BW Curran DP 《Tetrahedron》2007,63(35):8537-8562
Total syntheses of (−)-dictyostatin, 6,16-bis-epi-dictyostatin, 6,14,19-tris-epi-dictyostatin, and a number of other isomers and analogs are reported. Three main fragments—top, middle, and bottom—were first assembled and then joined by olefination or anionic addition reactions. After appending the two dienes at either end of the molecule, macrolactonization and deprotection completed the syntheses. The work proves both the relative and absolute configurations of (−)-dictyostatin. The compounds were evaluated by cell-based measurements of increased microtubule mass and antiproliferative activity, and in vitro tubulin polymerization assays as well as competitive assays with paclitaxel for its binding site on microtubules. These assays showed dictyostatin to be the most potent of the agents and further showed that the structural alterations caused from 20- to >1000-fold decreases in activity. 相似文献
114.
Vijayakumar S. RamachandraRao Bryan D. Vogt Ravi R. Gupta James J. Watkins 《Journal of Polymer Science.Polymer Physics》2003,41(23):3114-3126
The effect of carbon dioxide (CO2) sorption on the lower critical solution temperatures of deuterated polybutadiene/polyisoprene blends was determined with in situ small‐angle neutron scattering. CO2 was a poor solvent for both polymers and exhibited very weak selectivity between the blend components. The sorption of modest concentrations of CO2, at pressures up to 160 bar, induced phase segregation at temperatures well below the binary‐phase‐separation temperature and caused an increased asymmetry in the lower critical solution temperature curve. The origin of solvent‐induced phase segregation in this weakly interacting polymer blend system was attributed predominantly to an exacerbation of the existing disparity in the compressibility of the components upon CO2 sorption. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3114–3126, 2003 相似文献
115.
In this paper we study C0-semigroups on X × Lp( − h, 0; X) associated with linear differential equations with delay, where X is a Banach space. In the case that X is a Banach lattice with order continuous norm, we describe the associated modulus semigroup, under minimal assumptions on
the delay operator. Moreover, we present a new class of delay operators for which the delay equation is well-posed for p in a subinterval of [1,∞).
Dedicated to the memory of H. H. Schaefer 相似文献
116.
Axel Vogt 《Archiv der Mathematik》1985,45(3):275-281
Ohne Zusammenfassung 相似文献
117.
P. Sandel W. Vogt B. Popp und M. Knedel 《Fresenius' Journal of Analytical Chemistry》1976,279(2):126-127
Ohne Zusammenfassung
Smoothing-spline and polygonal interpolation, logit-log-linear- and logit-log-parabolic-regression: A comparative study of mathematical methods for the calculation of radioimmunoassay-results相似文献
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R. Vogt 《Zeitschrift fur Physik C Particles and Fields》1996,71(1):475-481
We discuss the renormalization and factorization scale dependence of charm and bottom production both at fixed-target energies and at present and future colliders. We investigate whether distributions calculable at leading order can be extrapolated to next-to-leading order by a constant multiplicative factor. 相似文献