University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Role of Genetic and Nongenetic Factors for Fluorouracil Treatment-Related Severe Toxicity: A Prospective Clinical Trial by the German 5-FU Toxicity Study Group

Abstract: Purpose To assess the predictive value of polymorphisms in dihydropyrimidine dehydrogenase (DPYD ), thymidylate synthase (TYMS ), and methylene tetrahydrofolate reductase (MTHFR ) and of nongenetic factors for severe leukopenia, diarrhea, and mucositis related to fluorouracil (FU) treatment. Patients and Methods A multicenter prospective clinical trial included 683 patients with cancer treated with FU monotherapy. Toxicity was documented according to World Health Organization grades. DPYD, TYMS, and MTHFR genotypes were determined, and DPYD was resequenced in patients with severe toxicity. Results Grade 3 to 4 toxicity occurred in 16.1% of patients. The sensitivity of DPYD*2A genotyping for overall toxicity was 5.5% (95%CI, 0.02 to 0.11), with a positive predictive value of 0.46 (95% CI, 0.19 to 0.75; P = .01). Inclusion of additional DPYD variants improved prediction only marginally. Analysis according to toxicity type revealed significant association of DPYD with mucositis and leukopenia, whereas TYMS w...

Shear deformable shell elements for large strains and rotations

Abstract: Well-known finite element concepts like the Assumed Natural Strain (ANS) and the Enhanced Assumed Strain (EAS) techniques are combined to derive efficient and reliable finite elements for continuum based shell formulations. In the present study two aspects are covered: The first aspect focuses on the classical 5-parameter shell formulation with Reissner–Mindlin kinematics. The above-mentioned combinations, already discussed by Andelfinger and Ramm for the linear case of a four-node shell element, are extended to geometrical non-linearities. In addition a nine-node quadrilateral variant is presented. A geometrically non-linear version of the EAS-approach is applied which is based on the enhancement of the Green–Lagrange strains instead of the displacement gradient as originally proposed by Simo and Armero. In the second part elements are derived in a similar way for a higher order, so-called 7-parameter non-linear shell formulation which includes the thickness stretch of the shell (Buchter and Ramm). In order to avoid artificial stiffening caused by the three dimensional displacement field and termed ‘thickness locking’, special provisions for the thickness stretch have to be introduced. © 1997 John Wiley & Sons, Ltd.

Isolation and characterization of Dehalospirillum multivorans gen. nov., sp. nov., a tetrachloroethene-utilizing, strictly anaerobic bacterium

Abstract: A strictly anaerobic bacterium dechlorinating tetrachloroethene (perchloroethylene, PCE) via trichloroethene (TCE) to cis-1,2-dichloroethene (DCE) was isolated from activated sludge with pyruvate plus PCE as energy substrates. The organism, called Dehalospirillum multivorans, is a gram-negative spirillum that does not form spores. The G+C content of the DNA was 41.5 mol%. According to 16S rRNA gene sequence analysis, D. multivorans represents a new genus and a new species belonging to the epsilon subdivision of Proteobacteria. Quinones, cytochromes b and c, and corrinoids were extracted from the cells. D. multivorans grew in defined medium with PCE and H2 as sole energy sources and acetate as carbon source; the growth yield under these conditions was 1.4g of cell protein per mol chloride released. Alternatively to PCE, fumarate and nitrate could serve as electron acceptors; sulfate could not replace fumarate, nitrate, or PCE in this respect. In addition to H2, the organism utilized a variety of electron donors for dechlorination (pyruvate, lactate, ethanol, formate, glycerol). Upon growth on pyruvate plus PCE, the main fermentation products formed were acetatc, lactate, DCE, and H2. At optimal pH (7.3–7.6) and temperature (30°C), and in the presence of pyruvate (20mM) and PCE (160μM), a dechlorination rate of about 50 nmol min-1 (mg cell protein)-1 and a doubling time of about 2.5h were obtained with growing cultures. The ability to reduce PCE to DCE appears to be constitutive under the experimental conditions applied since cultures growing in the absence of PCE for several generations immediately started dechlorination when transferred to a medium containing PCE. The organism may be useful for bioremediation of environments polluted with tetrachloroethene.

In vivo analysis of metabolic dynamics in Saccharomyces cerevisiae : I. Experimental observations

Abstract: The goal of this work was to obtain rapid sampling technique to measure transient metabolites in vivo. First, a pulse of glucose was added to a culture of the yeast Saccharomyces cerevisiae growing aerobically under glucose limitation. Next, samples were removed at 2 to 5 s intervals and quenched using methods that depend on the metabolite measured. Extracellular glucose, excreted products, as well as glycolytic intermediates (G6P, F6P, FBP, GAP, 3-PG, PEP, Pyr) and cometabolites (ATP, ADP, AMP, NAD(+), NADH) were measured using enzymatic or HPLC methods. Significant differences between the adenine nucleotide concentrations in the cytoplasm and mitochondria indicated the importance of compartmentation for the regulation of the glycolysis. Changes in the intra- and extracellular levels of metabolites confirmed that glycolysis is regulated on a time scale of seconds. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 305-316, 1997.