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A. H. Williams Ma Hta Kyu J. C. B. Fenton J. B. Cavanagh 《Journal of neurochemistry》1972,19(4):1073-1077
Abstract— Rats have been subjected to portocaval anastomosis and the ammonium ion in plasma and the glutamate and glutamine levels in plasma, red cells and brain have been estimated up to 6 weeks after operation. The glutamine, but not the glutamate, levels in brain were consistently raised, being about 2.5 times greater than normal and the level can be correlated with the level of plasma ammonium ion. Consideration is given to the possibility that the glutamine may be in the greatly enlarged neuroglial compartment in this abnormal metabolic state. 相似文献
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Shortfall of equipment for neonatal intensive care and the introduction of budget holding contracts.
As adequate allowance must be made for the costs of purchasing, maintaining, and updating equipment during the development of contracts the current standing of neonatal units with regard to available equipment was assessed. Data were collected as part of a one year prospective survey of the 17 perinatal units in the Trent region. Adequacy of provision of equipment for recognised intensive care cost was assessed using the recommendations of the British Paediatric Association and British Association of Perinatal Paediatrics. It was assumed that units without recognised intensive care cost had to be able to equip one cot to a standard of intensive care level 1 in the short term. Equipment more than 5 years old was considered likely to warrant replacement or major maintenance within the next two years. With these guidelines over 600,000 pounds would be required to provide sufficient equipment for all recognised level 1 intensive care cost and to allow units without funded cost to provide this level of care in the short term and to replace existing equipment more than 5 years old for these cost alone. This amount could be reduced by 25% by subdividing intensive care cost into levels 1 and 2, thereby reducing equipment requirements, but this would impair the units'' ability to perform level 1 care at funded provision, which has already been shown to need expansion. Neither figure takes account of equipment requirements for infants requiring special care. In addition, no allowance has been made for purchase or update of ultrasound scanners or blood gas analysers. If the government''s proposed reforms are to be implemented clinicians need to revise guidelines regarding essential equipment, and plans must be made to correct any existing shortfalls so that they do not become inherited financial liabilities for future budget holders. 相似文献
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Dated Plant Phylogenies Resolve Neogene Climate and Landscape Evolution in the Cape Floristic Region
In the context of molecularly-dated phylogenies, inferences informed by ancestral habitat reconstruction can yield valuable insights into the origins of biomes, palaeoenvironments and landforms. In this paper, we use dated phylogenies of 12 plant clades from the Cape Floristic Region (CFR) in southern Africa to test hypotheses of Neogene climatic and geomorphic evolution. Our combined dataset for the CFR strengthens and refines previous palaeoenvironmental reconstructions based on a sparse, mostly offshore fossil record. Our reconstructions show remarkable consistency across all 12 clades with regard to both the types of environments identified as ancestral, and the timing of shifts to alternative conditions. They reveal that Early Miocene land surfaces of the CFR were wetter than at present and were dominated by quartzitic substrata. These conditions continue to characterize the higher-elevation settings of the Cape Fold Belt, where they have fostered the persistence of ancient fynbos lineages. The Middle Miocene (13–17 Ma) saw the development of perennial to weakly-seasonal arid conditions, with the strongly seasonal rainfall regime of the west coast arising ~6.5–8 Ma. Although the Late Miocene may have seen some exposure of the underlying shale substrata, the present-day substrate diversity of the CFR lowlands was shaped by Pliocene-Pleistocene events. Particularly important was renewed erosion, following the post-African II uplift episode, and the reworking of sediments on the coastal platform as a consequence of marine transgressions and tectonic uplift. These changes facilitated adaptive radiations in some, but not all, lineages studied. 相似文献
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TO Sogbanmu AO Osibona OA Oguntunde AA Otitoloju 《African Journal of Aquatic Science》2018,43(3):281-292
Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l?1) was the most toxic, followed by pyrene (1.53 mg l?1) and naphthalene (7.21 mg l?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies. 相似文献