Zur Geschichte der Herren von Hagen

Soviel Licht auch bereits durch die sorgfältigen Untersuchungen des selb. Wenck's über die Genealogie obiger Herren verbreitet ist, so bietet dieselbe demohngeachtet noch so manche Dunkelheit und Lücke dar, deren Erhellung und Ausfüllung um so wünschenswerter erscheinen müssen, da jenes Herrengeschlecht sowohl durch Güterbesitz als auch durch die Persönlichkeit seiner Glieder eine sehr hervorragende Stellung einnahm. ..

Using of spouted bed spray granulation process for fabricating of metal/ceramic-polymer composites

Naturally occurring structural materials are composites with very high filling degrees on hard constituent. In recent years structure and properties of biological materials have been studied in detail. But it has not been possible to reconstruct this structural design. In this contribution we present a process for the fabrication of very highly filled composite materials by using of the spouted bed spray granulation process. Spouted bed granulation offers many advantages for the design of composite materials. In this investigation fine particles (dP =10-50 µm) could be uniformly spouted, and optimal properties for further processing to bulk materials can be obtained by means of granulation. For this a hybrid spouted bed with horizontal gas inlets was designed, which has a small prismatic process chamber with adjustable inlets and a high conical-cylindrical relaxation zone. The thickness of the polymer layer is adjusted by a two-fluid nozzle. The adjustment of the thickness of polymer layer is very important to fabricate composites of adjustable filling degrees. After granulation the particles are assembled to a composite material by means of warm pressing. Additionally for achievement of very high packing densities bimodal particle size distributions are used. For this purpose, particles in nm-range are firstly suspended in polymer solution and the suspension is sprayed in the spouted bed on coarser particles. Granulated particles are assembled to composites and mechanical properties of these were analysed by 4-point bending-tests. We gratefully acknowledge financial support from the German Research Foundation (DFG) via the collaborative research center SFB986. Please click Additional Files below to see the full abstract

A model for the onset of transport in systems with distributed thresholds for conduction

We present a model supported by simulation to explain the effect of temperature on the conduction threshold in disordered systems. Arrays with randomly distributed local thresholds for conduction occur in systems ranging from superconductors to metal nanocrystal arrays. Thermal fluctuations provide the energy to overcome some of the local thresholds, effectively erasing them as far as the global conduction threshold for the array is concerned. We augment this thermal energy reasoning with percolation theory to predict the temperature at which the global threshold reaches zero. We also study the effect of capacitive nearest-neighbor interactions on the effective charging energy. Finally, we present results from Monte Carlo simulations that find the lowest-cost path across an array as a function of temperature. The main result of the paper is the linear decrease of conduction threshold with increasing temperature: $V_t(T) = V_t(0) (1 - 4.8 k_BT P(0)/ p_c)$, where $1/P(0)$ is an effective charging energy that depends on the particle radius and interparticle distance, and $p_c$ is the percolation threshold of the underlying lattice. The predictions of this theory compare well to experiments in one- and two-dimensional systems.Comment: 14 pages, 10 figures, submitted to PR

Enhancing the Stabilization Potential of Lyophilization for Extracellular Vesicles

Extracellular vesicles (EV) are an emerging technology as immune therapeutics and drug delivery vehicles. However, EVs are usually stored at −80 °C which limits potential clinical applicability. Freeze-drying of EVs striving for long-term stable formulations is therefore studied. The most appropriate formulation parameters are identified in freeze-thawing studies with two different EV types. After a freeze-drying feasibility study, four lyophilized EV formulations are tested for storage stability for up to 6 months. Freeze-thawing studies revealed improved colloidal EV stability in presence of sucrose or potassium phosphate buffer instead of sodium phosphate buffer or phosphate-buffered saline. Less aggregation and/or vesicle fusion occurred at neutral pH compared to slightly acidic or alkaline pH. EVs colloidal stability can be most effectively preserved by addition of low amounts of poloxamer 188. Polyvinyl pyrrolidone failed to preserve EVs upon freeze-drying. Particle size and concentration of EVs are retained over 6 months at 40 °C in lyophilizates containing 10 mm K- or Na-phosphate buffer, 0.02% poloxamer 188, and 5% sucrose. The biological activity of associated beta-glucuronidase is maintained for 1 month, but decreased after 6 months. Here optimized parameters for lyophilization of EVs that contribute to generate long-term stable EV formulations are presented. © 2021 The Authors. Advanced Healthcare Materials published by Wiley-VCH Gmb