RESUMO
NMR, infrared and Raman vibrational spectra of alpha-cypermethrin have been measured at room temperature. Infrared spectra were also recorded to low temperature. The spectra were analyzed by means of ab initio calculations. The conformational space of both enantiomers and some rotamers A, B and C of alpha-cypermethrin has been scanned using molecular dynamics and complemented with functional density calculations that optimize the geometry of the lowest-energy conformers of each species as obtained in the simulations. The vibrational frequencies and the 1H and 13C NMR chemical shifts were assigned using functional density calculations. The molecular electrostatic potential maps were obtained and analyzed.
Assuntos
Modelos Químicos , Piretrinas/química , Análise Espectral Raman , Vibração , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Espectrofotometria Infravermelho , Eletricidade Estática , Estereoisomerismo , TermodinâmicaRESUMO
Magnetic resonance imaging has become a common tool for the diagnosis and management of osteoarticular infections in children. We retrospectively review the MRI findings in 57 children (age range 4 months to 16 years; mean 6.3 years) diagnosed with osteoarticular infection. Thirty-eight cases were osteomyelitis, 4 were septic arthritis, 6 were spondylodiscitis, 7 were soft-tissue infections, 2 were pyomyositis, and 2 were chronic multifocal osteomyelitis. The pathogenesis and classification of osteoarticular infections are briefly discussed. Currently available imaging techniques are reviewed, and advantages and disadvantages are discussed. Magnetic resonance imaging indications and findings are shown. The most adequate magnetic resonance imaging sequences, as well as the usefulness of intravenous contrast material, are stressed.