Ultrathin molecularly imprinted polymer sensors employing enhanced transmission surface plasmon resonance spectroscopy

An ultrathin novel nanosensor (31.5 +/- 4.1 nm thick in the absence of analytes), employing a molecularly imprinted polymer as a recognition element for cholesterol and gold nanoparticle enhanced transmission surface plasmon resonance spectroscopy for detection, was constructed.     

On the intersection theory of the moduli space of rank two bundles

We give an algebro-geometric derivation of the known intersection theory on the moduli space of stable rank 2 bundles of odd degree over a smooth curve of genus g. We lift the computation from the moduli space to a Quot scheme, where we obtain the intersections via equivariant localization with respect to a natural torus action.     

Synthesis and crystal structure of [La(NO3)3(H2O)2(BiPy)]·1.5(BiPy)

The molecular and crystal structure of the [La(NO₃)₃(H₂O)₂(2.2′-BiPy)]·1.5(2.2′-BiPy) compound is determined. The metal coordination polyhedron in the La(III) complex is formed from 10 donor atoms of O₈N₂: 6 oxygen atoms belong to three chelate-coordinated NO ₃ ^? anions, 2 oxygen atoms belong to two water molecules, and 2 nitrogen atoms belong to a bidentate bipyridine molecule coordinated in the neutral form. The structure is based on the metal complexes linked together in chains through the O(W)-H...O hydrogen bonds, in which oxygen atoms of the coordinated NO ₃ ^? anions act as acceptors. It is a framework structure, further stabilized by a system of O(W)-H...N and C-H...N hydrogen bonds, in which nitrogen atoms of the uncoordinated bipyridine molecules act as proton acceptors.     

Mechanical behavior during different weathering tests of the polyurethane elastomers films

Segmented poly(ester-urethane)elastomers (PU) based on poly(ethylene diethylene adipate) diols as a soft segment and aromatic diisocyanates in the hard segment were synthesized by a conventional method. The precipitated and compact polyurethane films have been degraded after a limited exposure to natural weathering. The effects on mechanical properties of precipitated and compact polyurethane films were found to be a measure of the degradation due to weathering. The present study attempts to correlate the physical-mechanical properties of the precipitated polyurethane and compact films with time of weathering. In all cases a certain amount of oxidative change had been initiated. This was probably associated with enzyme adsorption on surfaces. We compared natural weathering of PU films carried out in earth, seawater and exposure to sunlight with untreated samples. In common with other weathering tests, the effect was to decrease the ultimate tensile strain, except seawater. It was found that enzymatic degradation in the earth occurred only after, the ageing process was continuous and practically linear with a relatively short initial period of increase in degradation rate.     

Category bounds for nonnegative Ricci curvature manifolds with infinite fundamental group

This brief note presents refinements of the bounds on the first Betti number and the polynomial growth degree of the fundamental group for manifolds with nonnegative Ricci curvature and infinite fundamental group. These refinements are then sharpened when applied to symplectic manifolds.

     

Symmetric dithiodigalactoside: strategic combination of binding studies and detection of selectivity between a plant toxin and human lectins

Thioglycosides offer the advantage over O-glycosides to be resistant to hydrolysis. Based on initial evidence of this recognition ability for glycosyldisulfides by screening dynamic combinatorial libraries, we have now systematically studied dithiodigalactoside on a plant toxin (Viscum album agglutinin) and five human lectins (adhesion/growth-regulatory galectins with medical relevance e.g. in tumor progression and spread). Inhibition assays with surface-presented neoglycoprotein and in solution monitored by saturation transfer difference NMR spectroscopy, flanked by epitope mapping, as well as isothermal titration calorimetry revealed binding properties to VAA (K(a): 1560 ± 20 M(-1)). They were reflected by the structural model and the affinity on the level of toxin-exposed cells. In comparison, galectins were considerably less reactive, with intrafamily grading down to very minor reactivity for tandem-repeat-type galectins, as quantitated by radioassays for both domains of galectin-4. Model building indicated contact formation to be restricted to only one galactose moiety, in contrast to thiodigalactoside. The tested glycosyldisulfide exhibits selectivity between the plant toxin and the tested human lectins, and also between these proteins. Therefore, glycosyldisulfides have potential as chemical platform for inhibitor design.