Nucleobase modification as redox DNA labelling for electrochemical detection

Basic aspects of DNA electrochemistry with a strong focus on the use of modified nucleobases as redox probes for electrochemical bioanalysis are reviewed. Intrinsic electrochemical properties of nucleobases in combination with artificial redox-active nucleobase modifications are frequently applied in this field. Synthetic approaches (both chemical and enzymatic) to base-modified nucleic acids are briefly summarized and their applications in redox labelling are discussed. Finally, analytical applications including DNA hybridization, primer extension, PCR, SNP typing, DNA damage and DNA-protein interaction analysis are presented (critical review, 91 references).     

Independence of the axiomatic system for MV-algebras

We prove that the well-known axiomatic system of MV-algebras is not independent. The axiom of commutativity can be deleted and the remaining axioms are shown to be independent.     

Emission Spectrometric Analysis of Fresh Waters with U-Shaped D.C. Arc with Aerosol Supply

Abstract

The application of a U-shaped d.c. arc with aerosol supply for analysis of fresh waters has been described. Limits of detection obtained with d.c. plasma compare well with those reported for ICP. A number of spectral lines and molecular bands were examined and the most suitable are selected to ensure the best limits of detection or wide dynamic ranges. Limits of detection in ng ml^?1, given in the parenthesis, following the element symbol, are: Al(0.9), B(0.6), Ba(0.2), Be(0.15), Ca(0.05), Cd(3.5), Co(1.1), Cr(0.2), Fe(2.4), Ga(0.5), Hg(9.0), K(0.3), Li(0.008), Mg(0.4), Mn(0.3), Mo(0.7), Na(0.04), Ni(2.0), P(45), Pb(12), Si(9.0), Sr(0.04), Zn(1.3).     

First-Principles Calculations of the Instabilities in Fe-(Ni,Co, Pt) Alloys

First-principles calculations using the Korringa-Kohn-Rostocker method and the Coherent-Potential Approximation for Fe-Ni, Fe-Ni-Co and Fe-Pt alloys show that several features are responsible for the Invar anomalies. Atomic short range ordering in the alloys is responsible for the appearance of antiferromagnetic and non-colinear magnetic moments. The antiferromagnetic contributions are responsible for two effects, the negative anharmonicity due to the tendency of the alloys to have a smaller lattice constant, as well as the tendency to have a larger lattice constant because of additional density of states of antibonding majority-spin orbitals at the Fermi level, which simultaneously stabilizes the antiferromagnetic moments.     

ZnS:Cr and ZnSe:Cr thin‐film waveguide structures as electrically pumped laser media with an impact excitation mechanism

ZnS:Cr and ZnSe:Cr are the focus of studies as media for broadly tunable optically pumped lasers operating in the near‐ and mid‐IR regions. It is of great interest to obtain such lasers electrically pumped. The effective electrical excitation of Cr²⁺ ions was demonstrated only in the case of the impact mechanism for thin‐film structures with insulator layers between an electroluminescent film and electrodes, which prevent avalanche breakdown at high electric field (≥ 1 MV/cm). To obtain lasing, the waveguide electroluminescent structures were used. For the first time, the stimulated emission and the laser oscillation were demonstrated in the ZnS:Cr waveguide structures. Although the lasing is unstable as yet, these results lay the foundations of a new direction in laser physics aimed at creation of electrically pumped lasers by dint of impact excitation. Published results concerning various aspects of ZnS:Cr and ZnSe:Cr thin films and waveguide structures as promising electrically pumped laser media are reviewed. The causes of the instability of the laser oscillation and means of improving their characteristics are also considered.     

On Stability of M-stationary Points in MPCCs

We consider parameterized Mathematical Programs with Complementarity Constraints arising, e.g., in modeling of deregulated electricity markets. Using the standard rules of the generalized differential calculus we analyze qualitative stability of solutions to the respective M-stationarity conditions. In particular, we provide characterizations and criteria for the isolated calmness and the Aubin properties of the stationarity map. To this end, we introduce the second-order limiting coderivative of mappings and provide formulas for this notion and for the graphical derivative of the limiting coderivative in the case of the normal cone mapping to \(\mathbb {R}^{n}_{+}\) .     

A diquark model for baryons containing one heavy quark

We present a phenomenological ansatz for coupling a heavy quark with two light quarks to form a heavy baryon. The heavy quark is treated in the heavy mass limit, and the light quark dynamics is approximated by propagating scalar and axial vector ??diquarks??. The resulting effective lagrangian, which incorporates heavy quark and chiral symmetry, describes interactions of heavy baryons with Goldstone bosons in the low energy region. As an application, the Isgur-Wise form factors are estimated.     

Anomalous phase sequence in new chiral liquid crystalline materials

We have prepared and studied a series of rod-like liquid crystalline compounds with the molecular core laterally substituted by bromine atom and with the lactate unit in the chiral terminal chain. Microscopic observation under the polarising microscope, x-ray and dielectric spectroscopy results enable us to establish the TGBA–SmA–TGBA_RE–TGBC phase sequence. The presence of the re-entrant TGBA phase below the regular SmA phase, found for three homologues, is quite uncommon. Results are discussed and compared with the previously studied compounds with regular phase sequences.