70 research outputs found

    Localization and electrical characterization of interconnect open defects

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    A technique for extracting the electrical and topological parameters of open defects in process monitor lines is presented. The procedure is based on frequency-domain measurements performed at both end points of the line. The location as well as the resistive value of the open defect are derived from attenuation and phase shift measurements. The characteristic defect-free impedance of the line and its propagation constant are considered to be unknowns, and their values are also derived from the above measurements. In this way, the impact of process parameter variations on the proposed model is diminished. The experimental setup required to perform the characterization measurements and a simple graphical procedure to determine the defect and line parameters are presented. Experimental results show a good agreement between the predicted location of the open and its real location, found by optical beam induced resistance change inspection. Errors smaller than 2% of the total length of the line have been observed in the experiments.Postprint (published version

    Metabolic engineering of <i>Saccharomyces cerevisiae</i> for <i>de novo</i> production of dihydrochalcones with known antioxidant, antidiabetic, and sweet tasting properties

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    Dihydrochalcones are plant secondary metabolites comprising molecules of significant commercial interest as antioxidants, antidiabetics, or sweeteners. To date, their heterologous biosynthesis in microorganisms has been achieved only by precursor feeding or as minor by-products in strains engineered for flavonoid production. Here, the native ScTSC13 was overexpressed in Saccharomyces cerevisiae to increase its side activity in reducing p-coumaroyl-CoA to p-dihydrocoumaroyl-CoA. De novo production of phloretin, the first committed dihydrochalcone, was achieved by co-expression of additional relevant pathway enzymes. Naringenin, a major by-product of the initial pathway, was practically eliminated by using a chalcone synthase from barley with unexpected substrate specificity. By further extension of the pathway from phloretin with decorating enzymes with known specificities for dihydrochalcones, and by exploiting substrate flexibility of enzymes involved in flavonoid biosynthesis, de novo production of the antioxidant molecule nothofagin, the antidiabetic molecule phlorizin, the sweet molecule naringin dihydrochalcone, and 3-hydroxyphloretin was achieve

    Is a Federal European Constitution for an Enlarged European Union Necessary? Some Preliminary Suggestions Using Public Choice Analysis

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    Structure elucidation of polyamine toxins in the venom of the spider larinioides folium

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    The lyophilized venom of the spider Larinioides folium (Araneidae) was analyzed by high-performance liquid chromatography, coupled on-line to electrospray ionization mass spectrometry (HPLC-ESI-MS) and tandem mass spectrometry (HPLC-ESI-MS/MS), as well as UV-DAD analysis. In combination with amino acid analysis, high-resolution mass spectrometry and on-column H/D-exchange experiments, the structures of 41 new acylpolyamines contained in the complex venom of the spider L. folium were elucidated. Data interpretation in detail and the efficiency of this combined set of analytical method is exemplified by the structural elucidation of one of the toxins, namely of LF503a
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