Mass spectral fragmentation pattern of 2,2′-bipyridyls. Part VIII. 2,2′-Bipyridyl-5-carboxylic Acid and 2,2′-bipyridyl-5-sulphonic acid

The mass spectra of 2,2′-bipyridyl-5-carboxylic acid and 2,2′-bipyridyl-5-sulphonic acid obtained by electron impact are described. The principal initial fragmentation routes from the molecular ion of the carboxylic acid involve loss of CO, CN^˙, HCN, CO₂, OH^˙ and H₂O. From the molecular ion of the sulphonic acid the principal fragmentations are accompanied by loss of HCN, O₃, SO₂ and SO₃.     

Mass spectral fragmentation pattern of 2,2′-Bipyridyls. Part III. 2-(2-pyridyl)quinoline and 2,2′-Biquinoline

The mass spectral fragmentation patterns of 2-(2-pyridyl)quinoline and 2,2′-biquinoline are reported. The former rearranges to acridine derivatives on electron impact while the latter shows very little fragmentation.     

An algebraic characterization of vacuum states in Minkowski space

An algebraic characterization of vacuum states on nets ofC ^*-algebras over Minkowski space is given and space-time translations are reconstructed with the help of the modular structures associated with such states. The result suggests that a condition of geometrical modular action might hold in quantum field theories on a wider class of spacetime manifolds.     

Mass spectral fragmentation pattern of 2,2-bipyridyls. Part V. 2,2′-oxydipyridine

The mass spectrum of 2,2′-oxydipyridine obtained by electron impact is reported. The principal fragmentations involve loss of C₂IIO and CO in addition to rupture of the central bonds. Molecular rearrangements accompany the fragmentations.     

Maximal violation of Bell's inequalities is generic in quantum field theory

Under weak technical assumptions on a net of local von Neumann algebras {A(O)} in a Hilbert space , which are fulfilled by any net associated to a quantum field satisfying the standard axioms, it is shown that for every vector state in there exist observables localized in complementary wedge-shaped regions in Minkowski space-time that maximally violate Bell's inequalities in the state . If, in addition, the algebras corresponding to wedge-shaped regions are injective (which is known to be true in many examples), then the maximal violation occurs in any state on () given by a density matrix.     

Die Mikrobestimmung der relativen Feuchtigkeit zur Kontrolle osmophiler Hefen in Konditoreiprodukten

Ohne Zusammenfassung     

Knotting of random ring polymers in confined spaces

Stochastic simulations are used to characterize the knotting distributions of random ring polymers confined in spheres of various radii. The approach is based on the use of multiple Markov chains and reweighting techniques, combined with effective strategies for simplifying the geometrical complexity of ring conformations without altering their knot type. By these means we extend previous studies and characterize in detail how the probability to form a given prime or composite knot behaves in terms of the number of ring segments N and confining radius R. For 50 < or =N < or =450 we show that the probability of forming a composite knot rises significantly with the confinement, while the occurrence probability of prime knots are, in general, nonmonotonic functions of 1R. The dependence of other geometrical indicators, such as writhe and chirality, in terms of R and N is also characterized. It is found that the writhe distribution broadens as the confining sphere narrows.     

Novel sulfur-containing rapamycin analogs prepared by precursor-directed biosynthesis

[reaction: see text] Two novel sulfur-containing analogs of the immunosuppressive natural product rapamycin (1) were obtained by feeding cultures of Streptomyces hygroscopicus with l-nipecotic acid (4) and either (S)-1,3-thiazane-4-carboxylic acid (5) or (S)-1,4-thiazane-3-carboxylic acid (6). The structures of the two new compounds, 20-thiarapamycin (2) and 15-deoxo-19-sulfoxylrapamycin (3), were determined by spectroscopic methods.