RESUMO
Click chemistry refers to selective reactions developed for grafting of bio(macro)molecules in their biological media. Caged click compounds have been employed to spatiotemporally control click reactions. Here, we survey the uncaging of photo-dibenzocyclooctyne-OH (photoDIBO-OH) to its click-chemistry active form DIBO-OH, with particular attention to its conversion timescale and efficiency. Ultraviolet pump-infrared probe experiments reveal a stepwise decarbonylation: first, carbon monoxide (C≡O) is released within 1.8 ps, and then, it converts, within 10 ps, to DIBO-OH. Completion of uncaging is achieved with an efficiency of â¼50%. A successful demonstration of two-photon uncaging of photoDIBO-OH at long wavelength (700 nm) confers enhanced in vivo compatibility and proceeds on the same timescale.
Assuntos
Automóveis , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/fisiologia , Postura/fisiologia , Adulto , Cadáver , Fêmur/anatomia & histologia , Fêmur/diagnóstico por imagem , Fêmur/fisiologia , Articulação do Quadril/diagnóstico por imagem , Humanos , Ílio/anatomia & histologia , Ílio/diagnóstico por imagem , Ílio/fisiologia , Processamento de Imagem Assistida por Computador , Modelos Anatômicos , Pelve/anatomia & histologia , Pelve/diagnóstico por imagem , Pelve/fisiologia , Radiografia , Análise de RegressãoRESUMO
The aim of this study was to quantify the mechanical properties of the muscles of the buttock, using dynamic compression (5-->30 Hz). Tests were conducted in vitro on porcine muscles, using a lever arm device, which applied a dynamic load onto cylindrical samples. A two-parameter viscoelastic model allowed the calculation of stiffness and damping of the samples with respect to frequency. The average stiffness curve showed a monotonous increase (5 Hz: 8.5 kN/m-->30 Hz: 347 kN/m). Concerning damping, between 5 and 20 Hz, values were typically inferior to 300 Ns/m, which then increased till 30 Hz (556 Ns/m). The lever arm device may be used to evaluate dynamic properties of other biological tissues also.