Erzeugung von Cordierit-Keramikschäumen über die Zwischenstufe hochgefüllter Polyurethan-Schaumstoffe

Der Beitrag berichtet von der Entwicklung von leichten keramischen Massen mit speziellen Schaumstrukturen. Hierzu wurden geeignete Ausgangsstoffe ermittelt sowie ein Verfahren entwickelt, das seine Leistungsfähigkeit mit Keramikformkörpern demonstriert hat. Die Arbeiten beinhalteten im Kern die Entwicklung eines neuartigen Verfahrens der Herstellung keramischer Schaumstoffe mittels PUR-Systemen auf der Basis von Recyclatpolyolen, wobei die keramischen Pulver (u. a. aufbereitete Schlacken und Cordierit-Keramik aus dem Recycling von Abgas-Katalysatoren) in niedrigviskose Polyole eingebracht und anschließend mit Isocyanaten zu anorganisch-organischen Verbundschaumstoffen geschäumt wurden. Die organischen Bestandteile wurden anschließend ausgebrannt und zuletzt die Keramik gesintert. An den erhaltenen Formkörpern wurden mechanische Kennwerte bestimmt, die Strukturen mikroskopisch charakterisiert und Gebrauchswerteigenschaften erfasst. Die entwickelten keramischen Schaumstoffe können als in der Kälte formbeständige Körper für entsprechend belastete Bauteile herangezogen werden und eignen sich zudem als Trägermaterialien für Katalysatoren oder für Aufgaben im Bereich der Filtration.In this paper we report on the development of light ceramic foams of special structures. To this end, suitable raw materials and processing parameters were established to demonstrate the properties and performance of the products. The investigation incorporates the development of a new process to produce foamed ceramics by means of PUR systems based on recycling polyols. Thus, the ceramic powders (amongst others processed slag and cordierite originating from the recycling of car catalysts) were mixed with low viscosity polyols and foamed by the reaction with isocyanates forming structured inorganic-organic composites. In the following step, the organic component was burned out and the ceramic materials simultaneously sintered. Mechanical properties of the resulting ceramic bodies were determined, structures were investigated by microscopicy, and properties for technical use received. The ceramic foams produced are useful to serve as dimensionally stable bodies for low temperature use for special parts in cryogenics, as a substrate for biocatalysts, as precious metal free catalysts in Diesel engine exhaust, or for tasks in the fi eld of fi ltration

Systems Biology Graphical Notation: Process Diagram Level 1

Standard graphical representations have played a crucial role in science and engineering throughout the last century. Without electrical symbolism, it is very likely that our industrial society would not have evolved at the same pace. Similarly, specialised notations such as the Feynmann notation or the process flow diagrams did a lot for the adoption of concepts in their own fields. With the advent of Systems Biology, and more recently of Synthetic Biology, the need for precise and unambiguous descriptions of biochemical interactions has become more pressing. While some ideas have been advanced over the last decade, with a few detailed proposals, no actual community standard has emerged. The Systems Biology Graphical Notation (SBGN) is a graphical representation crafted over several years by a community of biochemists, modellers and computer scientists. Three orthogonal and complementary languages have been created, the Process Diagrams, the Entity Relationship Diagrams and the Activity Flow Diagrams. Using these three idioms a scientist can represent any network of biochemical interactions, which can then be interpreted in an unambiguous way. The set of symbols used is limited, and the grammar quite simple, to allow its usage in textbooks and its teaching directly in high schools. The first level of the SBGN Process Diagram has been publicly released. Software support for SBGN Process Diagram was developed concurrently with its specification in order to speed-up public adoption. Shared by the communities of biochemists, genomicians, theoreticians and computational biologists, SBGN languages will foster efficient storage, exchange and reuse of information on signalling pathways, metabolic networks and gene regulatory maps

Flupenthixol in relapse prevention in schizophrenics with comorbid alcoholism: Results from an open clinical study

Substance use, especially alcoholism, has been recognized as a significant problem in schizophrenic patients, though only a few studies on the effects of pharmacotherapy in these patients have been conducted so far. The thioxanthene neuroleptic flupenthixol, which can be given intramuscularly (i.m.) for improving compliance, has been studied as a possible anti-craving drug both in animal models of alcoholism and some clinical studies. Pilot studies suggest that comorbid schizophrenics with substance use may benefit from treatment with flupenthixol. Efficacy of flupenthixol (10-60 mg i.m.) in reducing alcohol consumption of dual diagnosis patients was studied in an open 6-month clinical trial in 27 schizophrenics with comorbid alcoholism. Twenty-one patients entered the intention-to-treat analysis. Fourteen subjects were completers, 13 dropped out. Six patients completely abstained from alcohol during treatment. Alcohol consumption was significantly reduced compared to baseline (4 weeks before treatment as measured by timeline follow-back interview). In general, while patients showed a marked improvement concerning alcohol consumption, only a slight improvement in psychopathology was recorded. Overall tolerability was good. These data indicate a probable beneficial effect of flupenthixol in schizophrenic patients with comorbid alcoholism. Although the efficacy of flupenthixol as an anti-craving drug in dual diagnosis patients has to be explored in further studies, the drug may be considered a promising medication for these patients. Copyright (C) 2003 S. Karger AG, Basel

Bound states in two-dimensional spin systems near the Ising limit: A quantum finite-lattice study

We analyze the properties of low-energy bound states in the transverse-field Ising model and in the XXZ model on the square lattice. To this end, we develop an optimized implementation of perturbative continuous unitary transformations. The Ising model is studied in the small-field limit which is found to be a special case of the toric code model in a magnetic field. To analyze the XXZ model, we perform a perturbative expansion about the Ising limit in order to discuss the fate of the elementary magnon excitations when approaching the Heisenberg point.Comment: 21 pages, 18 figures, published versio

Olfactory ensheathing glia are required for embryonic olfactory axon targeting and the migration of gonadotropin-releasing hormone neurons.

Kallmann's syndrome is caused by the failure of olfactory axons and gonadotropin-releasing hormone (GnRH) neurons to enter the embryonic forebrain, resulting in anosmia and sterility. Sox10 mutations have been associated with Kallmann's syndrome phenotypes, but their effect on olfactory system development is unknown. We recently showed that Sox10 is expressed by neural crest-derived olfactory ensheathing cells (OECs). Here, we demonstrate that in homozygous Sox10(lacZ/lacZ) mouse embryos, OEC differentiation is disrupted; olfactory axons accumulate in the ventromedial olfactory nerve layer and fewer olfactory receptor neurons express the maturation marker OMP (most likely owing to the failure of axonal targeting). Furthermore, GnRH neurons clump together in the periphery and a smaller proportion enters the forebrain. Our data suggest that human Sox10 mutations cause Kallmann's syndrome by disrupting the differentiation of OECs, which promote embryonic olfactory axon targeting and hence olfactory receptor neuron maturation, and GnRH neuron migration to the forebrain.This work was supported by the Wellcome Trust [grant 091555 to C.V.H.B. and P.B.], a Griffith University Encouragement Research grant to J.A.S., and Deutsche Forschungsgemeinschaft [grant We1326/9 to M.W.].This is the final version of the article. It was first available from The Company of Biologists via http://dx.doi.org/10.1242/bio.2013524