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21.
Stephanie Kaspar Diana Weier Winfriede Weschke Hans-Peter Mock Andrea Matros 《Analytical and bioanalytical chemistry》2010,398(7-8):2883-2893
Both the nucellar projection (NP) and endosperm transfer cells (ETC) of the developing barley grain (harvested 8 days after flowering) were isolated by laser capture micro-dissection combined with pressure catapulting. Protein extracts were analyzed by nanoUPLC separation combined with ESI-Q-TOF mass spectrometry. The majority of the ~160 proteins identified were involved in translation, protein synthesis, or protein destination. The NP proteome was enriched for stress defense molecules, while proteins involved in assimilate transport and the mobilization of nutrients were common to both the NP and the ETC. The combined qualitative and quantitative protein profiling allowed for the identification of several proteins showing tissue specificity in their expression, which underlines the distinct biological functions of these two tissues within the developing barley grain. 相似文献
22.
O. Kaspar Personne Schneider W. Lenz und E. Kock 《Fresenius' Journal of Analytical Chemistry》1882,21(1):294-295
Ohne Zusammenfassung 相似文献
23.
Kaspar Nipp 《BIT Numerical Mathematics》2002,42(2):408-439
The dynamics of a differential algebraic equation takes place on a lower dimensional manifold in phase space. Applying a numerical integration scheme, it is natural to ask if and how this geometric property is preserved by the discrete dynamical system. In the index-1 case answers to this question are obtained from the singularly perturbed case treated by Nipp and Stoffer, Numer. Math. 70 (1995), 245–257, for Runge-Kutta methods and in K. Nipp and D. Stoffer, Numer. Math. 74 (1996), 305–323, for linear multistep methods. As main result of this paper it is shown that also for Runge-Kutta methods and linear multistep methods applied to a index-2 problem of Hessenberg form there is a (attractive) invariant manifold for the discrete dynamical system and this manifold is close to the manifold of the differential algebraic equation. 相似文献
24.
We prove that the Chern character of quantum algebras is invariant under a class of deformations of the Dirac operator. We also extend the definition of the Chern character to include certain unbounded operators. 相似文献
25.
Dettmer K Nürnberger N Kaspar H Gruber MA Almstetter MF Oefner PJ 《Analytical and bioanalytical chemistry》2011,399(3):1127-1139
Trypsin/ethylenediaminetetraacetic acid (EDTA) treatment and cell scraping in a buffer solution were compared for harvesting
adherently growing mammalian SW480 cells for metabolomics studies. In addition, direct scraping with a solvent was tested.
Trypsinated and scraped cell pellets were extracted using seven different extraction protocols including pure methanol, methanol/water,
pure acetone, acetone/water, methanol/chloroform/water, methanol/isopropanol/water, and acid–base methanol. The extracts were
analyzed by GC-MS after methoximation/silylation and derivatization with propyl chloroformate, respectively. The metabolic
fingerprints were compared and 25 selected metabolites including amino acids and intermediates of energy metabolism were quantitatively
determined. Moreover, the influence of freeze/thaw cycles, ultrasonication and homogenization using ceramic beads on extraction
yield was tested. Pure acetone yielded the lowest extraction efficiency while methanol, methanol/water, methanol/isopropanol/water,
and acid–base methanol recovered similar metabolite amounts with good reproducibility. Based on overall performance, methanol/water
was chosen as a suitable extraction solvent. Repeated freeze/thaw cycles, ultrasonication and homogenization did not improve
overall metabolite yield of the methanol/water extraction. Trypsin/EDTA treatment caused substantial metabolite leakage proving
it inadequate for metabolomics studies. Gentle scraping of the cells in a buffer solution and subsequent extraction with methanol/water
resulted on average in a sevenfold lower recovery of quantified metabolites compared with direct scraping using methanol/water,
making the latter one the method of choice to harvest and extract metabolites from adherently growing mammalian SW480 cells. 相似文献
26.
J. Gwinner H. Läpple Ch. Schneeweiß H. G. Bartels E. Kaspar K. -H. Waldmann R. Horst R. Hebel H. Späth 《Mathematical Methods of Operations Research》1977,21(4):B159-B164
Ohne Zusammenfassung 相似文献
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The Lewis acid isomerisation of a dioxaspirodecanol mixture, obtained by photochemical means, preferentially gives the cis isomer while acetylation mainly leads to the trans isomer. The theromolysis of the acetates 2 or the xanthates 5 yields a furan compound 4, enventual precursor of a dioxaspirolactone. 6. The xanthate reduction provides an easy access to th e methyl-4 dioxaspirodecane isomers of wasp pheromones. 相似文献
30.