Selective electrochemical recognition of ions in solution and at self-assembled monolayers

Quinone-functionalized calix[4]arenes having carboxylic acid groups or thiol groups were prepared and their spontaneous adsorption on silver and gold surfaces, respectively, was studied. Since the cavity-like structure of calixarenes was immobilized on the noble metal electrodes, they exhibited a selective affinity towards specific hard metal ions in aqueous media. Voltammetric and spectroscopic studies showed the well-ordered deposition of organic receptors and entrapment of metal ions. It also was found that the repeated capture and removal of metal ions reversibly with chelating agents such as ethylenediaminetetraacetic acid (EDTA) was possible. This is the first example, to our knowledge, of voltammetric detection of hard metal ions in aqueous media using a chemically modified electrode with redox-active macrocyclic receptors.     

Generating and Adding Flows on Locally Complete Metric Spaces

As a generalization of a vector field on a manifold, the notion of an arc field on a locally complete metric space was introduced in Bleecker and Calcaterra (J Math Anal Appl, 248: 645–677, 2000). In that paper, the authors proved an analogue of the Cauchy–Lipschitz Theorem, i.e they showed the existence and uniqueness of solution curves for a time independent arc field. In this paper, we extend the result to the time dependent case, namely we show the existence and uniqueness of solution curves for a time dependent arc field. We also introduce the notion of the sum of two time dependent arc fields and show existence and uniqueness of solution curves for this sum.     

Nuclear orbiting and anomalies in nuclear reactions

In this paper, we report our measurements of back-angle oxygen and carbon particle yields from ¹⁶O+⁸⁹Y, ¹²C+⁹³Nb reactions forming the same compound nucleus ¹⁰⁵Ag at the same excitation energy and spin distribution. We find anomalously large oxygen yield and entrance channel dependence at high excitation energies from ¹⁶O+⁸⁹Y reaction implying formation of a dinuclear orbiting complex. Possible connection between nuclear orbiting and fast fission is also discussed.     

Power flow model of flexural waves in finite orthotropic plates

In this paper, an approximate power flow model is developed for the analysis of the flexural waves in finite orthotropic plate transversely vibrating in the medium-to-high frequency ranges. The derived energy equation for the model is expressed with time- and locally space-averaged farfield wave energy density. It could be the more general form than that of the conventional power flow analysis model seen in the isotropic plate. With the derived model, dynamic characteristics varying with the direction can be expressed. To verify the validity and accuracy of the model, numerical analyses are performed for the case where a finite rectangular plate is excited by a harmonic point force, and the calculated results expressed with the energy levels are compared with classical modal solutions by changing the frequency and the damping loss factor of the plate. The dominant power transmission paths in the plate are also predicted from the distribution of the approximate intensity fields.     

Precision analysis of Nb−Ti ratio in a superconducting alloy by NAA-PIXE combined technique

A NAA-PIXE combined analysis has been applied to the precise measurement of the concentrations of Nb and Ti in Nb–Ti alloy ingot. The ingot is used in the production of superconductors and the concentration should be controlled very strictly. The ingot cross section could be analyzed with an accuracy of better than 1% by the use of NAA for the preparation of standard samples and PIXE for the nondestructive rapid scan of the surface. The radial and azimuthal concentration profiles of the ingot could be obtained.     

Microfluidic chip analysis of outer membrane proteins responsible for serological cross-reaction between three Gram-negative bacteria: Proteus morganii O34, Escherichia coli O111 and Salmonella Adelaide O35

Bacterial strains have complex and individual antigenic structure, which provides basis for their serological identification. However, serological cross-reaction may occur when antibodies against a certain strain recognize other strains too. The molecular basis of this phenomenon is the expression of similar or identical antigenic epitopes on the surface of different bacterial cells. Such cross-reactions might harden the serological diagnosis of pathogenic bacteria. But it can be also advantageous, when antigens of non-pathogenic strains can be used in the serological examinations. Serological cross-reaction between three taxonomically different strains--Proteus morganii O34 (8662/64), Escherichia coli O111 and Salmonella Adelaide O35--have been described. It has been proven that it is based partially on the similar lipopolysaccharide structures of these pathogens. In this study the involvement of the outer membrane proteins of these strains in the serological cross-reaction is presented. Microfluidic chip technology was applied for the detection of common proteins, which provided fast and quantitative data about the proteins that might be responsible for serological cross-reaction. Two outer membrane proteins with apparent molecular mass of 36 and 41 kDa, respectively, could be detected in the profile of each strain, while individual dominating protein peaks have also appeared in the protein profiles. The presence of common protein antigens was proven by Western blotting.