Klonierung und heterologe Expression der Guanylatzyklase-D (GC-D) aus der Maus und Entwicklung von Aktivitätstests zur Ligandensuche

Signal transduction in most olfactory sensory neurons of vertebrates is initiated by the binding of odorants to G-protein-coupled receptors in the ciliary membrane. The activation of the odorant receptor initiates a signal transduction cascade leading to an increase of intracellular cAMP. In a small subpopulation of olfactory sensory neurons, a cGMP-dependent pathway seems to be involved, since none of the components of the cAMP pathway were found in these cells. These neurons express a membrane bound guanylate cyclase, the GC-D. The physiological ligand of the GC-D has not been identified yet. The GC-D may be activated by pheromone-like odorants that control social behavior and suckling. In the present study the cDNA of the GC-D from mouse (mGC-D) was cloned from genomic DNA. Specific antibodies against the GC-D were used to localize the protein in the subpopulation of olfactory sensory neurons in the mouse olfactory epithelium. The mGC-D protein was expressed in eucaryontic cell lines. Two assays were developed to measure the protein activity of GC-D with the goal of detecting the physiological ligand of the protein. The first assay is an in vitro system. Here, the activation of the mGC-D protein is measured by the amount of cGMP formed by the protein. A small GC-D activity, the basal activity, could be measured in the absence of ligand. In order to increase the sensitivity of the assay, the recombinant mGC-D protein can be solubilised and purified by affinity chromatography. A purification protocol was tested and has to be optimized. The second assay is a cellular system. Here, the GC-D and a cGMP-sensitive ion channel are coexpressed in an eucaryontic cell line. The binding of the ligand leads to the activation of GC-D. The increase of formed cGMP inside the cell opens the ion channels. Ca$^{2+}$ ions from the extracellular medium flow into the cell. The intracellular Ca$^{2+}$ concentration can be monitored by Ca$^{2+}$-sensitive fluorescence dyes. This assay is very sensitive due to signal amplification by the Ca$^{2+}$ influx through opened ion channels. In further experiments the ligand of the GC-D may be identified using the described assays. Various body fluids of mice should be divided in their single components and applicated in the assays, in order to detect a possible activation ofthe GC-D

Aqueous organic redox-flow-batteries: from electrolyte development to detailed stability studies

To reach the political aims of the Kyoto Protocol and the Paris Agreement, the energy production must change from fossil fuels to sustainable sources like water, sun, and wind. But the fluctuation output of these techniques must be compensated by a smart grid. Herein, the integration of large-scale energy storage systems is inevitable. The possibility to use cheap organic molecules in “green” and non-toxic electrolytes make the emerging technology of organic redox flow batteries a promising candidate for this mission. Nevertheless, this battery concept suffers from many problems. One of the major ones is the insufficient stability of the active materials. To overcome this technical teething trouble, a combination of material and sensor development to investigate and mitigate decomposition processes is required. But currently, the research is more focused on development of new redox-active molecules with intrinsically higher stabilities than on investigating, understanding, and improving the underlying processes. Beside some exceptions, most research groups concentrate on demonstrating stabilities by cycling the material as often as possible. In addition, the influence of the used SOC of the battery is mostly uninvestigated. A battery management system which might limit the used SOC could improve the device lifespan. Therefore, precise, fast, and cheap monitoring systems for SOC and SOH determination are needed. The commonly applied techniques suffer from major drawbacks, like expensive equipment, material limitations, temperature dependency, and the need for (re)calibrations to name only a few. A protocol that is capable of monitoring these parameters on the electrolyte level and not on the battery level could unlock a deeper understanding of the ongoing processes inside the device or electrolyte. Possible device lifespan improvements could then not only be addressed by the material itself but also by the cycling conditions or other external factors

Investigating the actinomycete diversity inside the hindgut of an indigenous termite, Microhodotermes viator

Includes abstract.Includes bibliographical references.Ever since the discovery of a cellulolytic actinomycete inside the gut of a termite, there has been considerable interest in the metabolic abilities and the diversity of these bacteria within this complex environment. However, until fairly recently, most investigations of termite hindguts involved the higher termites from the Termitidae family. Little attention was paid to the lower termites, and even less to the family Hodotermitidae. The main aim of this project was to explore the actinobacterial diversity of the paunch and colon hindgut regions of one particular member of the family Hodotermitidae, Microhodotermes viator. No previous work of this nature has ever been attempted on this particular termite species

Friedrich II. von Preussens De la littérature allemande. Zum historischen Standort des Aufsatzes und zu seiner Übersetzung im Spanischen. Literarische und kulturhistorische Aspekte

Se reexamina el concepto de literatura que está en la base del ensayo sobre la literatura alemana (1780) de Federico II, que es un concepto tradicional y mucho más amplio que el que ahora utilizamos, pues se refiere a las letras en general y no a la literatura como ‘bellas letras’: se propone como posible instigador del ensayo a F. M. von Grimm que había publicado en 1750 dos Cartas sobre la literatura alemana en París. Ello conduce a concluir que las susceptibilidades que el ensayo generó entre los autores alemanes de la época y que repercute todavía en las discusiones del siglo XX se basa en un malentendido de las intenciones del autor. Este malentendido no se extiende a España, donde la sólida fama del monarca por un lado y el interés iluminista por el otro llevó a que se privilegiaran los aspectos pedagógicos y las intenciones formativas del breve libro. Se discute también la fecha de una reseña editada en 1781 en el Correo Literario y su incidencia en la traducción, publicada bajo siglas hasta ahora no comprendidas en 1787.The concept of literature used by Frederick II, King of Prussia, in his essay on German Literature is reexamined in this paper. We propose as one of the instigators for writing the original essay Friedrich Melchior von Grimm, who wrote two articles on German Literature in 1750, years before his famous Correspondence Littéraire. The concept of literature as used in the essay is a traditional concept, much broader than we use it nowadays, for it refers to all written products, not to literature as “belles lettres”. This means that some suspicacies which came about among the German authors of the time and which have still been discussed during the XXth Century are based on a faulty understanding of the author’s meaning. This misunderstanding does not extend to Spain, since the Prussian monarchs solid fame abroad and the illuminist interests in Spain led to reception, in the first instance, of the essays pedagogical aspects and formative intentions. W discuss also a review which was published in the Correo Literario in 1781 and its incidence in the Spanish translation, which was published anonymously in 1787

Colaboradores de Brecht.

Sin resume

Witte, Bernd (ed.), Goethe-Handbuch.

Sin resume

Brecht, Bertolt. Más de cien poemas.

Sin resume

Benefits of on-wafer calibration standards fabricated in membrane technology

In this work we compare on-wafer calibration standards fabricated in membrane technology with standards built in conventional thin-film technology. We perform this comparison by investigating the propagation of uncertainties in the geometry and material properties to the broadband electrical properties of the standards. For coplanar waveguides used as line standards the analysis based on Monte Carlo simulations demonstrates an up to tenfold reduction in uncertainty depending on the electromagnetic waveguide property we look at