RESUMO
The cross section of the process e^{+}e^{-}âπ^{+}π^{-} has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on an integrated luminosity of about 88 pb^{-1}, of which 62 pb^{-1} represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed.
RESUMO
The synthesis, photophysical characteristics, in vivo photosensitizing efficacy, human serum albumin (HSA) binding properties, and skin phototoxicity of some stable bacteriochlorins were investigated. The novel bacteriochlorins, obtained from chlorophyll-a, have long-wavelength absorptions in the range lambda max = 734-758 nm. Preferential migration of ethyl over methyl substituents among ketobacteriochlorins obtained in the pinacol-pinacolone rearrangements of vic-dihydroxybacteriochlorins was confirmed by NOE studies. The bacteriochlorins show relatively low fluorescence quantum yields. Among all the bacteriochlorins the triplet states were quenched by ground state molecular oxygen in a relatively similar manner, yielding comparable singlet oxygen quantum yields. In preliminary in vivo studies (DBA/2 mice, transplanted with SMT/F tumors), ketobacteriochlorins were found to be more photodynamically active than the related vic-dihydroxy analogues. Replacement of the methyl ester functionalities with di-tert-butylaspartic acids enhanced the in vivo efficacy. Site specific human serum albumin (HSA) binding studies indicated a direct correlation between the ability of the compound to bind to the diazepam binding site (albumin site II) and the in vivo photosensitizing efficacy.
Assuntos
Fármacos Fotossensibilizantes/química , Porfirinas/química , Albumina Sérica/metabolismo , Animais , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Diazepam/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos DBA , Modelos Químicos , Neoplasias Experimentais/tratamento farmacológico , Fármacos Fotossensibilizantes/metabolismo , Porfirinas/metabolismo , Ligação Proteica , Espectrofotometria AtômicaRESUMO
[formula: see text] A novel approach for the preparation of symmetrical (chlorin-chlorin), and unsymmetrical (chlorin-porphyrin) dimers joined with carbon-carbon linkages as models to study the "intramolecular" charge transfer is discussed.