Saarland University

About: Saarland University is a education organization based out in Saarbrücken, Germany. It is known for research contribution in the topics: Population & Medicine. The organization has 19555 authors who have published 39678 publications receiving 1109295 citations. The organization is also known as: University of the Saarland & Universität des Saarlandes.

Injection of subunits of cyclic AMP-dependent protein kinase into cardiac myocytes modulates Ca2+ current.

Abstract: β-Adrenergic stimulation of the heart is thought to increase cardiac muscle contractility by activation of cyclic AMP-dependent protein kinase and concomitant increase in the phosphorylation of certain proteins (for refs see refs 1–6). Electrophysiological studies have shown that the stimulation of cardiac β-adrenoreceptors7, the external application of cyclic AMP or its analogues to Purkinje fibres8, or the injection of cyclic AMP into single myocytes9 can increase the slow inward current (Isi) during the plateau phase of the action potential (AP). In heart muscle this current is mainly carried by Ca2+ (refs 10, 11) and it has been suggested that cyclic AMP-dependent phosphorylation of some component of the calcium channel increases the amount of Ca2+ which enters the cell during depolarization10. We have investigated this hypothesis by examining the electrical responses of isolated guinea pig ventricular myocytes to pressure injections of subunits of the cyclic AMP-dependent protein kinase. We report here that injection of the catalytic subunit (C) resulted in a lengthening of the action potential duration (APD) and an increase in the height of the plateau as well as the amplitude of Isi. By contrast, the injection of regulatory subunit (R) shortened the APD of fast and slow response APs, an effect which was reversed by adrenaline.

Predicting vulnerable software components

Abstract: Where do most vulnerabilities occur in software? Our Vulture tool automatically mines existing vulnerability databases and version archives to map past vulnerabilities to components. The resulting ranking of the most vulnerable components is a perfect base for further investigations on what makes components vulnerable.In an investigation of the Mozilla vulnerability history, we surprisingly found that components that had a single vulnerability in the past were generally not likely to have further vulnerabilities. However, components that had similar imports or function calls were likely to be vulnerable.Based on this observation, we were able to extend Vulture by a simple predictor that correctly predicts about half of all vulnerable components, and about two thirds of all predictions are correct. This allows developers and project managers to focus their their efforts where it is needed most: "We should look at nsXPInstallManager because it is likely to contain yet unknown vulnerabilities.".

Volume change during the formation of nanoporous gold by dealloying.

Abstract: We report a macroscopic shrinkage by up to 30 vol % during electrochemical dealloying of Ag-Au. Since the original crystal lattice is maintained during the process, we suggest that the formation of nanoporous gold in our experiments is accompanied by the creation of a large number of lattice defects and by local plastic deformation.

Single photon emission from silicon-vacancy colour centres in chemical vapour deposition nano-diamonds on iridium

Abstract: We introduce a process for the fabrication of high-quality, spatially isolated nano-diamonds on iridium via microwave-plasma-assisted chemical vapour deposition (CVD) growth. We perform spectroscopy of single silicon-vacancy (SiV) centres produced during the growth of the nano-diamonds. The colour centres exhibit extraordinary narrow zero-phonon-lines down to 0.7 nm at room temperature. Single photon count rates up to 4.8 Mcps at saturation make these SiV centres the brightest diamond-based single photon sources to date. We measure for the first time the fine structure of a single SiV centre, thus confirming the atomic composition of the investigated colour centres.