RESUMO
The use of amidoxime-functionalized polymer fibers as a sorbent for uranium has attracted recent interest for the extraction of uranium from seawater. Vanadium is one of the main competing ions for uranium sorption as V(v) species, however, vanadium is also present as V(iv) in seawater. In the present study, the interactions of V(iv) with amidoxime and similar ligands were explored. Attempts were made to synthesize V(iv) complexes of glutaroimide-dioxime, a molecular analogue of polymer sorbents. However, V(iv) was found to react irreversibly with glutaroimide-dioxime and other oxime groups, oxidizing to the V(v) oxidation state. We have explored the reactions and propose mechanisms, as well as characterized the redox behavior of the vanadium-glutaroimide-dioxime complex.
RESUMO
Breathing, heart and gait frequencies, tidal volume, cardiac output, and rates of oxygen consumption were measured in tammar wallabies (Macropus eugenii Desmarest) hopping on a treadmill. At speeds greater than 1.6 ms-1 the rate of metabolic power consumption was independent of hopping speeds. Blood lactate levels within the speed range where VO2 was independent of speed showed a mean increase of 4.8 mmol l-1. During bipedal hopping, the frequencies of breathing and limb movement are phase-locked in the ratio of 1:1. Inspiration begins as the animal leaves the ground and may be a passive process driven by a visceral piston. A relatively large central tendon in the diaphragm may correlate this function. Unlike breathing frequencies, cardiac frequencies show no entrainment with hopping. The site of dissipation of the presumed large arterial pressure excursion is unknown.
Assuntos
Marcha , Frequência Cardíaca , Macropodidae/fisiologia , Marsupiais/fisiologia , Respiração , Animais , Débito Cardíaco , Diafragma/anatomia & histologia , EletrocardiografiaRESUMO
The "cherry red" laryngoscopic appearance of adult epiglottitis, as visualized through a fiberscope, is reproduced. The possible role of the fiberoptic bronchoscope, both as a diagnostic aid and as a means of facilitating endotracheal intubation, in this condition, is discussed.
Assuntos
Broncoscópios , Epiglotite/diagnóstico , Laringite/diagnóstico , Feminino , Tecnologia de Fibra Óptica , Humanos , Pessoa de Meia-IdadeRESUMO
In a malignant hypertensive, steady control of blood pressure at a pre-determined level has been achieved with the continuous intravenous infusion of sodium nitroprusside. A microprocessor was programmed to assess the patient's blood pressure and adjust the rate of nitroprusside infusion so that a mean pressure of 106 mmHg was achieved. Brief interruption of the nitroprusside infusion allowed the effectiveness of changes in oral therapy to be evaluated. Thiocyanate concentrations were measured throughout as an index of potential nitroprusside toxicity. After six days, blood pressure control was maintained with oral therapy alone and papilloedema had almost resolved.
