Mechanistic Considerations of Bending‐Strain Effects within Organic Semiconductors on Polymer Dielectrics

The development of organic transistors for flexible electronics requires the understanding of device behavior upon the application of strain. Here, a comprehensive study of the effect of polymer‐dielectric and semiconductor chemical structure on the device performance under applied strain is reported. The systematic change of the polymer dielectric results in the modulation of the effects of strain on the mobility of organic field‐effect transistor devices. A general method is demonstrated to lower the effects of strain in devices by covalent substitution of the dielectric surface. Additionally, the introduction of a hexyl chain at the peripheries of the organic semiconductor structure results in an inversion of the effects of strain on device mobility. This novel behavior may be explained by the capacitative coupling of the surface energy variations during applied strain.     

Nanostructuring polymeric materials by templating strategies

This contribution summarizes efforts in designing, assembling/synthesizing, and structurally and functionally characterizing nanostructured materials using anodized aluminum oxide (AAO) as a thin-film template. Optical waveguide spectroscopy, using a nanoporous template as the guiding structure, is a particularly powerful analytical tool. The layer-by-layer approach for the fabrication of multilayer assemblies is shown to allow the fabrication of nanotube arrays. In addition to using dendrimers as building blocks, semiconducting nanomaterial (e.g., quantum dot) hybrid architectures with very interesting photophysical properties can be assembled. These can be employed, for example, in biosensing applications. Other strategies for using the AAO layers as templates include the growth of polymeric nanorod arrays from different functional monomers, which, after the dissolution of the template, are still able to guide light. This opens up novel concepts for integrated optics platforms with nanostructured materials.     

Adapted random sampling patterns for accelerated MRI

Objective  

Variable density random sampling patterns have recently become increasingly popular for accelerated imaging strategies, as they lead to incoherent aliasing artifacts. However, the design of these sampling patterns is still an open problem. Current strategies use model assumptions like polynomials of different order to generate a probability density function that is then used to generate the sampling pattern. This approach relies on the optimization of design parameters which is very time consuming and therefore impractical for daily clinical use.     

The Influence of the Phase Morphology on the Optoelectronic Properties of Light‐Emitting Electrochemical Cells

We report on the morphological aspects of thin films prepared from a blue–green light‐emitting conjugated polymer, (methyl‐substituted ladder‐type poly(p‐phenylene, mLPPP)), blended with a solid‐state electrolyte composed either by a crown ether, dicyclohexano‐18‐crown‐6 (DCH18C6), or a high‐molecular‐weight poly(ethylene oxide) (HMWPEO), and a Li salt, lithium trifluoromethanesulfonate (LiCF₃SO₃, Li triflate (LiTf)), as they have been successfully applied in light‐emitting electrochemical cells (LECs). The surface morphologies of the blend layers were investigated using atomic force microscopy (AFM) in tapping mode, and the ion distribution was probed using X‐ray analysis by means of energy‐dispersive X‐ray spectrometry (EDXS) in the scanning electron microscope (SEM). We show that the two different phase‐separation processes, the complexation tendencies of the ionic species as well as the ionic transport numbers, have tremendous influence on the performances of the corresponding LECs, revealing either rectifying or symmetric optoelectronic characteristics in forward and reverse bias directions. This opens up new possibilities for tuning the optoelectronic properties of ion‐supported organic electronic devices.     

Vergleich der Verteilung und Toxizität von α-, β- und γ-Hexachlorcyclohexan (HCH) nach 30tägiger Verabreichung an Ratten

Administration of 1000 ppm α-HCH, 600 ppm β-HCH and β 125 ppm γ-HCH to rats caused a growth retardation. α-HCH and β-HCH led to livermass enlargement. β-HCH caused a decrease of absolute brainmass. In case of α-HCH and γ-HCH fat tissue, kidneys and adrenals had a high burden in residues. Fat tissue and adrenals had high residues of β-HCH. The level of HCH-residues during the test period was γ ≦ β < α. The results are discussed taking into account the contradictory knowledge from literature.     

Physical and linkage mapping of the gene for the alpha3 chain of type IX collagen, COL9A3, to human chromosome 20q13.3

Type IX collagen is a minor cartilage component which associates with mixed fibrils of types II/XI collagen. We have determined the precise physical and genetic locations for the gene encoding the alpha3 chain of type IX collagen, COL9A3. Utilizing fluorescence in situ hybridization, radiation hybrid mapping, and multipoint linkage analysis, we have mapped COL9A3 to human chromosome 20q13.3, 13 cM telomeric to D20S173.     

A metastable phase diagram for sputter-deposited NiLa alloys

Amorphous Ni_1?xLa_x thick films (0.02 ? x ? 0.30) were prepared by high-rate sputter deposition. Alloy phase compositions were determined by X-ray diffraction analysis following isothermal annealing treatments at temperatures up to 850°C. Results are presented in the form of a metastable phase diagram, which is compared with the equilibrium phase diagram of the NiLa system.