Electronically Excited States
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Linear aliphatic triplet aldehydes: enzymatic formation and effects in biological structures / Aldeídos alifáticos lineares triplete: formação enzimática e efeitos em estruturas biológicas
Peroxidase de rábano ("horseradish peroxidase - HRP), atuando como uma oxidase frente a substratos apropriados, catalisa a formação de espécies eletronicamente excitadas triplete. Os produtos obtidos são os esperados da clivagem de um intermediário 1,2-dioxetânico hipotético. Espécies tripletes geradas enzimaticamente são capazes de transferir ener
Publicado em: 1984
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2. An observation concerning electronically excited retinal
The observation of Mathies and Stryer of highly polar excited electronic states of all-trans-retinal, its unprotonated Schiff base, a salt of the protonated Schiff base, and 11-cis-retinal leads us to propose a possible consequence of the existence of such species. The highly polar excited molecule may have sufficient potential to oxidize its surroundings, t
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3. Bioluminescence of the firefly: key steps in the formation of the electronically excited state for model systems.
The chemcial mechanism for formatin of electronically excited-state molecules from the thermal reaction of dimethyldioxetanone was studied. Light production in the presence of certain easily oxidized aromatic hydrocarbons was found not to conform to the classical mechanistic schemes for chemiexcitation. Detailed investigation of the dioxetanone system reveal
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4. Energy transfer from PO excited states to alkali metal atoms in the phosphorus chemiluminescence flame
Phosphorus chemiluminescence under ambient conditions of a phosphorus oxidation flame is found to offer an efficient electronic energy transferring system to alkali metal atoms. The lowest resonance lines, 2P3 / 2,½→2S½, of potassium and sodium are excited by energy transfer when an argon stream at 80°C carrying potassium or sodium atoms intersects a ph
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5. The nature of the excited state of the reaction center of photosystem II of green plants: A high-resolution fluorescence spectroscopy study
We studied the electronically excited state of the isolated reaction center of photosystem II with high-resolution fluorescence spectroscopy at 5 K and compared the obtained spectral features with those obtained earlier for the primary electron donor. The results show that there is a striking resemblance between the emitting and charge-separating states in t
The National Academy of Sciences.
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6. Even-odd alternation in mass spectrum of thymine and uracil clusters: Evidence of intracluster photodimerization
Multiphoton ionization of thymine and uracil clusters generated by a supersonic molecular beam gave rise to a remarkable alternation of mass spectral intensities between even- and odd-numbered clusters. Such alternation was observed in clusters of up to 30 molecules. Excitation to the two lowest electronically excited states seemed to be a strong prereq
The National Academy of Sciences.
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7. Nanosecond time-resolved circular polarization of fluorescence: study of NADH bound to horse liver alcohol dehydrogenase.
Circularly polarized luminescence (CPL) spectroscopy provides information on the excited-state chirality of a lumiphore analogous but complementary to information regarding the ground-state chirality derived from circular dichroism. The sensitivity of CPL spectra to molecular conformation makes this technique uniquely suited for the study of biomolecular str
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8. Single-Molecule Spectroscopy Reveals that Individual Low-Light LH2 Complexes from Rhodopseudomonas palustris 2.1.6. Have a Heterogeneous Polypeptide Composition
Rhodopseudomonas palustris belongs to the group of purple bacteria that have the ability to produce LH2 complexes with unusual absorption spectra when they are grown at low-light intensity. This ability is often related to the presence of multiple genes encoding the antenna apoproteins. Here we report, for the first time to our knowledge, direct evidence tha
The Biophysical Society.
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9. Electrostatic field around cytochrome c: theory and energy transfer experiment.
Energy transfer in the "rapid diffusion" limit from electronically excited terbium(III) chelates in three different charge states to horse heart ferricytochrome c was measured as a function of ionic strength. Theoretical rate constants calculated by numerical integration of the Forster integral (containing the Poisson-Boltzmann-generated protein electrostati