A note on the theory of limit processes for solving finite equations

Summary In the first of the two paragraphs a limit operator for solving equationG(x)=0 in the bounds of abstract Banach space has been developed. Theorem 1 contains the results obtained, and it is in two respects an extension of a known theorem due to Rheinboldt. The main result appears in the fact that in the assumptions of the later theorem the Lipschitz condition has been weakened to the form of the Hölder condition. Instead of a limitpoint, the existence of a limitoperator, which maps a finite neighbourhood of the root into the root itself, and so guarantees the numerical stability of the process, represents another extension included in Theorem 1.—In the second paragraph it has been shown that the Hölder condition is also sufficient for the convergence and validity of the Newton sequences, i.e. of the primary form of the modified Newton sequences and of the original one.     

Hands help hearing: facilitatory audiotactile interaction at low sound-intensity levels

Auditory and vibrotactile stimuli share similar temporal patterns. A psychophysical experiment was performed to test whether this similarity would lead into an intermodal bias in perception of sound intensity. Nine normal-hearing subjects performed a loudness-matching task of faint tones, adjusting the probe tone to sound equally loud as a reference tone. The task was performed both when the subjects were touching and when they were not touching a tube that vibrated simultaneously with the probe tone. The subjects chose on average 12% lower intensities (p < 0.01) for the probe tone when they touched the tube, suggesting facilitatory interaction between auditory and tactile senses in normal-hearing subjects.     

Dielectrophoretic trapping of multilayer DNA origami nanostructures and DNA origami‐induced local destruction of silicon dioxide

DNA origami is a widely used method for fabrication of custom‐shaped nanostructures. However, to utilize such structures, one needs to controllably position them on nanoscale. Here we demonstrate how different types of 3D scaffolded multilayer origamis can be accurately anchored to lithographically fabricated nanoelectrodes on a silicon dioxide substrate by DEP. Straight brick‐like origami structures, constructed both in square (SQL) and honeycomb lattices, as well as curved “C”‐shaped and angular “L”‐shaped origamis were trapped with nanoscale precision and single‐structure accuracy. We show that the positioning and immobilization of all these structures can be realized with or without thiol‐linkers. In general, structural deformations of the origami during the DEP trapping are highly dependent on the shape and the construction of the structure. The SQL brick turned out to be the most robust structure under the high DEP forces, and accordingly, its single‐structure trapping yield was also highest. In addition, the electrical conductivity of single immobilized plain brick‐like structures was characterized. The electrical measurements revealed that the conductivity is negligible (insulating behavior). However, we observed that the trapping process of the SQL brick equipped with thiol‐linkers tended to induce an etched “nanocanyon” in the silicon dioxide substrate. The nanocanyon was formed exactly between the electrodes, that is, at the location of the DEP‐trapped origami. The results show that the demonstrated DEP‐trapping technique can be readily exploited in assembling and arranging complex multilayered origami geometries. In addition, DNA origamis could be utilized in DEP‐assisted deformation of the substrates onto which they are attached.     

Self‐Assembly of Amphiphilic Janus Dendrimers into Mechanically Robust Supramolecular Hydrogels for Sustained Drug Release

Compounds that can gelate aqueous solutions offer an intriguing toolbox to create functional hydrogel materials for biomedical applications. Amphiphilic Janus dendrimers with low molecular weights can readily form self‐assembled fibers at very low mass proportion (0.2 wt %) to create supramolecular hydrogels (G′?G′′) with outstanding mechanical properties and storage modulus of G′>1000 Pa. The G′ value and gel melting temperature can be tuned by modulating the position or number of hydrophobic alkyl chains in the dendrimer structure; thus enabling exquisite control over the mesoscale material properties in these molecular assemblies. The gels are formed within seconds by simple injection of ethanol‐solvated dendrimers into an aqueous solution. Cryogenic TEM, small‐angle X‐ray scattering, and SEM were used to confirm the fibrous structure morphology of the gels. Furthermore, the gels can be efficiently loaded with different bioactive cargo, such as active enzymes, peptides, or small‐molecule drugs, to be used for sustained release in drug delivery.     

Analysis of Chlorinated Phenols,Phenoxyphenols and Dibenzofurans Around Wood Preserving Facilities

Abstract

Until presently chlorophenol containing wood preservative has been widely used in Finland to protect timber, lumber, plywood and fiberboard against rot and bluestaining fungi at saw mills. We analysed soil, ground water, runoff and workers' urine at several saw mills for the presence of the various chemical components of the commercial wood preservative.

We found serious local contamination of soil with chlorophenols and also with the minor, potentially very toxic minor constituents of the commercial product, namely polychlorinated phenoxyphenols and dibenzofurans. Chlorophenols were observed to contaminate soil at great depth. Ground water, surface water and also workers' urine was found contaminated by chlorophenols. Polychlorinated phenoxyphenols and dibenzofurans were found in great quantity (equal or close to that of chlorophenols) in the topmost 5cm of soil at the sawmill area, but these compounds had not penetrated into the soil at such great depth as did chlorophenols.     

A Fluoro-Chromogenic Sensor Based on Organic Molecular Framework for Cu<Superscript>2+</Superscript> and F<Superscript>−</Superscript> in Aqueous Soluble DMSO

The 2,2′-dinaphtholazobenzene molecular framework (P) was designed, synthesized and characterized. Its absorption and fluorescence properties revealed that P is a dual sensor for copper ions (Cu²⁺) and fluoride ions (F^?) in DMSO. The colorimetric activities were clearly visible by naked eye upon the addition of the two ions. Fluorescence quenching and enhancement were observed when Cu²⁺ and F^? ions were added respectively. Density Functional Theory (DFT) calculations were carried out to provide an insight into the interaction of guest ions (Cu²⁺ and F^?) with P, and to explain how the molecular orbitals were affected.

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