Synthesis of DNA with phenanthridinium as an artificial DNA base

A phenanthridinium-containing DNA building block was synthesized as an ethidium nucleoside analogue starting from 3,8-diamino-6-phenyl-phenanthridine. Using this building block, oligonucleotides bearing the phenanthridinium moiety as an artificial DNA base were prepared via automated solid-phase phosphoramidite chemistry. The modified phenanthridinium-containing DNA duplexes were characterized by UV/vis absorption spectroscopy (including the melting behavior), CD spectroscopy, and steady-state fluorescence spectroscopy. These experiments reveal the expected similarity of the synthetic phenanthridinium moiety with noncovalently bound ethidium. More importantly, the results show clearly that the artificial phenanthridinium base is intercalated within the DNA base stack. The counterbase as part of the complementary strand seems to have only a minor influence on the intercalation properties of the phenanthridinium moiety.     

Non-Fermi liquid regimes in U1−xMxPd2Al3(M=Y,Th)

The temperature-composition (T–x) phase diagram and NFL characteristics in the electrical resistivity ρ(T), specific heat C(T), and magnetic susceptibility χ(T) at low temperatures for the systems U_1−xM_xPd₂Al₃ (M=Y,Th) are described. The T–x phase diagram, the NFL characteristics, and the underlying mechanism for the NFL behavior are distinctly different for M=Y³⁺ and Th⁴⁺, apparently reflecting the difference in valence of the M atom substituents, and suggesting that U is tetravalent in these two systems.     

Coagulation-Fragmentation Processes

We study the well-posedness of coagulation-fragmentation models with diffusion for large systems of particles. The continuous and the discrete case are considered simultaneously. In the discrete situation we are concerned with a countable system of coupled reaction-diffusion equations, whereas the continuous case amounts to an uncountable system of such equations. These problems can be handled by interpreting them as abstract vector-valued parabolic evolution equations, where the dependent variables take values in infinite-dimensional Banach spaces. Given suitable assumptions, we prove existence and uniqueness in the class of volume preserving solutions. We also derive sufficient conditions for global existence. Accepted: (August 18, 1999)     

Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment

We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.     

Dual semigroups and second order linear elliptic boundary value problems

It is shown that general second order elliptic boundary value problems on bounded domains generate analytic semigroups onL ₁. The proof is based on Phillips’ theory of dual semigroups. Several sharp estimates for the corresponding semigroups inL _p, 1≦p<∞, are given.     

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Zum Galerkin-Verfahren für die hammersteinsche gleichung

Ohne Zusammenfassung Vorgelegt von J. Serrin