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991.
1. A pseudomonad capable of utilizing 4-chlorophenoxyacetate (CPA) as sole source of organic carbon was isolated from soil. 2. The organism was grown in liquid culture and the following compounds were isolated and identified in culture extracts: 4-chloro-2-hydroxyphenoxyacetate, 4-chlorocatechol, beta-chloromuconate probably the cis-trans isomer and gamma-carboxymethylene-Delta(alphabeta)-butenolide. 3. Cells grown on 4-chlorophenoxyacetate were able to metabolize 4-chloro-2-hydroxyphenoxyacetate, 4-chlorocatechol and gamma-carboxymethylene-Delta(alphabeta)-butenolide without a lag period. They were not adapted to 4-chlorophenol, or to either culture isolated or synthetic beta-chloromuconate, possibly because of stereospecificity towards the cis-cis isomer. 4. On the basis of isolation and induction evidence, the following metabolic pathway is proposed for the breakdown of 4-chlorophenoxyacetate by this organism: 4-chlorophenoxyacetate --> 4-chloro-2-hydroxyphenoxyacetate --> 4-chlorocatechol --> cis-cis-beta-chloromuconate --> gamma-carboxymethylene-Delta(alphabeta)-butenolide --> maleylacetate and fumarylacetate --> fumarate and acetate. 相似文献
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R. J. Courtenay Evans M. K. Benson D. T. D. Hughes 《BMJ (Clinical research ed.)》1971,1(5748):530-531
Nine patients with tabes dorsalis and one patient with diabetic autonomic neuropathy were subjected to hypoxia to test the integrity of their carotid chemoreceptors. Ventilation and pulse rate changes were monitored and compared with those of a group of normal subjects of comparable age and sex. Four patients had a completely negative response to hypoxia, and the changes in ventilation in the group of patients as a whole were significantly less than in the control subjects. The results indicate that some patients with autonomic denervation are unable to adjust their respiratory system in response to hypoxia. 相似文献
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Displacement of histones from deoxynucleoprotein by protamine 总被引:2,自引:0,他引:2
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Under the assumption that there is complete mixing in the dead space a series of equations are given which give the values
for a washout test of the functional component of the pulmonary bellows (without a dead space) in terms of the washout values
of the bellows with a dead space. 相似文献