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'fluorescence' in keywords Facet   Publication Year 1986  [X]
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1Author    Herrn, Dr, DrRequires cookie*
 Title    Transanulare Wechselwirkung bei  
 Abstract    [m.n]Phanen, 32 [1]: Modelle für Amin-Aromaten-Exciplexe: [2](l,4)Anthraceno[2](2,6)pyridinophan-l,13-dien Transanular Interaction in [m .n]Phanes, 32 [1 ]: Models for Am ine-A rene-Exciplexes: [2](l,4)A nthraceno[2](2,6)pyridinophan-l,13-dien M atthias W. H a e n e l* 3, Birgit L intnera und D ieter Schweitzer11 a M ax-Planck-Institut für K ohlenforschung, Kaiser-W ilhelm -Platz 1, D-4330 M ülheim a .d . Ruhr b M ax-Planck-Institut für M edizinische Forschung, A bteilung M olekulare Physik, Jahnstraße 29, D -6900 H eidelberg The [2](1.4)A nthracen o[2](2,6)pyridinop han-l,13-d ien (5) and the corresponding [2.2]phane (7) were synthesized as m odels for exciplexes. The dithia[3.3]phanes (9) and (11) were prepared by cyclisation o f the dithiols 13 and 16 with the dibrom ide 19. O xidation of 9 to the disulfone 10 and vapour phase pyrolysis led to 7. Ring contraction o f 9 by S-analogous Wittig ether rearrange­ ment led to 20 which was converted to the diene 5 via oxidation to the disulfoxide 21 and pyrolytic elim ination o f m ethane sulfenic acid. A ttem pts to prepare 6 and 8 via similar routes from 11 failed. Electron absorption spectra and fluorescence spectra o f 5 and 7 are discussed in terms of n-n interaction in 5 and jt-jt interaction in 7. 
  Reference    Z. Naturforsch. 41b, 223 (1986); eingegangen am 7. Oktober 1985 
  Published    1986 
  Keywords    Cyclophanes, Electronic Interaction, Exciplex M odels U V Spectra, Fluorescence 
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 TEI-XML for    default:Reihe_B/41/ZNB-1986-41b-0223.pdf 
 Identifier    ZNB-1986-41b-0223 
 Volume    41 
2Author    B. Ernd, F. Ussm, Ann, P. Ete, D. AnRequires cookie*
 Title    Polymerization of Actin in the Absence and Presence of Cytochalasin B: Problems of Determining "Critical Concentration"  
 Abstract    A Various concentrations o f actin (0.3 or 1 mM MgCl2, 1 mM A T P , 1 mM E G T A) reached their final degree o f polym erization (m easured by a pyrene dye attached to actin) earlier in the pres­ ence o f cytochalasin B than in its absence. The curves relating concentrations o f polym eric F-actin to total actin concentration were under these conditions highly nonlinear making an unam biguous extrapolation to zero F-actin concentration (to deduce the "critical concentration" o f actin poly­ m erization) im possible. The concentration o f actin, above which polym erization occurred, was unaltered by cytochalasin B (although for reasons not yet understood the specific fluorescence intensity of polym erized actin was lower in the presence of cytochalasin B than in its absence). The results show that a distinct "critical concentration" o f actin polymerization must not always be well defined. 
  Reference    Z. Naturforsch. 41c, 781 (1986); received April 23 1986 
  Published    1986 
  Keywords    ctin, Cytochalasin B, Critical Concentration, Fluorescence, Polymerization 
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 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0781.pdf 
 Identifier    ZNC-1986-41c-0781 
 Volume    41 
3Author    ThorB. Melø, Gro ReisaeterRequires cookie*
 Title    Photodestruction of Endogenous Porphyrins in Relation to Cellular Inactivation of Propionibacterium acnes  
 Abstract    of Propionibacterium acnes on Eagles medium protoporphyrin was accumulated inside the cells and coproporphyrin, both as a free base as metalcontaining, outside the cells. The photochemical processes in the endogenous porphyrins were studied by fluorescence spectroscopy during continuous irradiation of Propionibacterium acnes in suspension. The irradiation caused initially an increase in the content of protoporphyrin in the cells in comparison to that which had been accumulated during growth. Maximum light induced protoporphyrin production was achieved in 5 days old cultures. In old cultures where there was practically no initial protoporphy­ rin release, the fluorescence intensities from all the porphyrins present in the culture vanished exponentially with the irradiation time. The metal containing form of fluorescent coproporphyrin, with a maximum emission at 580 nm, was photobleached about ten times faster than the free base forms of coproporphyrin and protoporphyrin. Among these three fluorescent substances in the cell culture only the free base forms of the porphyrins have longer lifetimes than the cells themselves irradiated at the same conditions. 
  Reference    Z. Naturforsch. 41c, 867 (1986); received February 28/June 3 1986 
  Published    1986 
  Keywords    Propionibacterium acnes, Porphyrins, Photooxidation, Fluorescence, Survival During growth 
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 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0867.pdf 
 Identifier    ZNC-1986-41c-0867 
 Volume    41