Defining functional interactions during biogenesis of epithelial junctions

In spite of extensive recent progress, a comprehensive understanding of how actin cytoskeleton remodelling supports stable junctions remains to be established. Here we design a platform that integrates actin functions with optimized phenotypic clustering and identify new cytoskeletal proteins, their functional hierarchy and pathways that modulate E-cadherin adhesion. Depletion of EEF1A, an actin bundling protein, increases E-cadherin levels at junctions without a corresponding reinforcement of cell-cell contacts. This unexpected result reflects a more dynamic and mobile junctional actin in EEF1A-depleted cells. A partner for EEF1A in cadherin contact maintenance is the formin DIAPH2, which interacts with EEF1A. In contrast, depletion of either the endocytic regulator TRIP10 or the Rho GTPase activator VAV2 reduces E-cadherin levels at junctions. TRIP10 binds to and requires VAV2 function for its junctional localization. Overall, we present new conceptual insights on junction stabilization, which integrate known and novel pathways with impact for epithelial morphogenesis, homeostasis and diseases

Synthesis of optically pure 5-fluoroalkyl-4-sulfinylisoxazoles

The title heterocycles (6) are prepared with complete regioselectivity by reaction of nitrile oxides (3) with the sodium enolates (4) of optically pure beta-oxo-gamma-fluoro sulfoxides

Ultrasonic characterization of state and properties of Al-based metal matrix composites

In a comprehensive experimental study ultrasonic techniques are optimized and used to characterize the state and to evaluate the properties of Al-based Al2O3 fiber reinforced MMC-parts. It has been the objective to concentrate on those ultrasonic techniques which can be applied on real parts in order to demonstrate the ultrasonic potential in a quality assurance concept for MMC-mass products, like automotive pistons and con-rods. It is found that the ultrasonic backscattering to visualize the distribution of the reinforcing phase in surface layers as well as in the bulk of components is very informative although the results are of qualitative nature only. The evaluation of quantitative values of the local concentration on reinforcements as well as of the Young's and shear moduli are possible by measuring the ultrasonic velocities or time-of-flight. Information on the elastic anisotropy resp. isotropy is gained from measurements using linear polarized shear waves. The pulse distortion o f a longitudinal wave is found to be suitable to detect misalignments of continous fibers

Ultrasonic characterization of burrs in aluminium pressure castings

There are always burrs in hollow castings. They are caused by the joining of the different streams of molden alloy and they can be areas of poor mechanical properties. Up to now, burrs are checked destructively using samples cut from the head and tail of the pressure casted product. It is found that the ultrasonic backscattering is suitable to visualize the fine grained microstructure of the seam area of the burr and the surrounding coarse grained area with higher content of impurities. The direction dependency of ultrasonic time-of-flight is used to characterize the crystallographic texture in the burr region. The texture is found to be different in the burr and in the adjacent areas and this difference changes along the length of the pressed part. The combination of ultrasonic backscattering and time-of-flight measurements is seen as a very promising nondestructive approach to characterize the burr and to determine the length of the pressure casted product with well developed mechani cal propertie