RESUMO
Four time-domain oriented, real-time frequency estimators, based on the detection of phase, zero-crossings, instantaneous frequency or autocorrelation, were simulated on a digital computer and subjected to computer generated Doppler signals, enabling the investigation of the influence of spectral shape, filtering, frequency shift, noise and quantitation. Three estimators, the autocorrelator as well as the instantaneous frequency detector and the autocorrelator, both with extended frequency range, appeared to be very accurate. They exhibit a bias in the estimator output of less than 2 percent over a wide frequency range, the former up to nearly the Nyquist frequency, the latter two beyond, even for skew spectra and under poor signal conditions regarding bandwidth and noise.
Assuntos
Simulação por Computador , Efeito Doppler , Física , Reologia , Velocidade do Fluxo Sanguíneo , Modelos Teóricos , Fenômenos FísicosRESUMO
The case-history of a 7-year-old boy with endocarditis, myocarditis and pericarditis, possibly caused by Coxiella burnetii (Q-fever), is presented. As far as we know only one case of Q-fever endocarditis in a child is previously described in literature. That child had, contrary to our patient, a pre-existing valve abnormality. Q-fever was diagnosed after demonstration of a significant rise in titer of the antibodies against Coxiella burnetii in both the IgM and the IgG fractions. IgA antibodies, indicative for an endocarditis, were also demonstrated.
Assuntos
Endocardite Bacteriana/etiologia , Miocardite/etiologia , Pericardite/etiologia , Febre Q , Doença Aguda , Antígenos de Bactérias/isolamento & purificação , Criança , Coxiella/imunologia , Endocardite Bacteriana/complicações , Humanos , Masculino , Miocardite/complicações , Pericardite/complicações , Febre Q/diagnósticoRESUMO
Thirteen propionyl-CoA carboxylase (PCC)-deficient fibroblast lines were analysed for complementation by examining the incorporation of [14C]propionate into trichloroacetic-acid insoluble cellular macromolecules of polyethylene-glycol-dimethyl-sulphoxide induced heterokaryons formed by fusion of mutant cell lines. Corrections for variations in the rate of protein synthesis of the heterokaryons and individual cell lines was made by measuring the incorporation of [3H]lysine, added simultaneously with the labelled propionate. Two distinct complementation groups were found in this sample of PCC-deficient cell lines. Evidence for intragenic complementation was not obtained.
