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51.
The influence of a single injection of delta-sleep-inducing peptide (DSIP; 30 g/kg body weight) on neurochemical parameters of rats' brain was studied under the conditions of chronic administration of dopamine analogs inducing DA-system hyperactivity – 50 mg/kg body weight of L-DOPA for 30 days or 2,5 mg/kg body weight of amphetamine for 21 days. The parameters of serotonergic system (MAO A activity, 5-HT, and 5-HIAA contents) and of dopaminergic system (MAO B activity, DA, NA, and HVA contents) were investigated in the cortex and caudate nucleus of control, DA or amphetamine, and DSIP receiving rats. Changes caused by the two DA-system activating drugs had both similarities and differences, and the corrective action of DSIP also had certain peculiarities depending on the pharmacological preparation used for the induction of DA-system hyperactivity and on the investigated brain structure. It is supposed that DSIP action might be based on the activation of serotonergic system that ensures the adaptive behavior of the animals. 相似文献
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A heat-labile protein has been identified in fruit bodies of the edible mushroom, Agaricus bisporus, which protects Raji cells (a human lymphoma cell line) against H2O2-induced oxidative damage to cellular DNA. This protein has been purified following salt fractionation, combined with ion-exchange, hydrophobic interaction and adsorption chromatography. Based on catalytic and electrophoretic properties, and inhibition studies using tropolone, the protein was identified as tyrosinase. The genoprotective effect of A. bisporus tyrosinase, determined using the single-cell gel electrophoresis met") assay, has been shown to be dependent upon the enzymic hydroxylation of tyrosine to L-DOPA and subsequent conversion of this metabolite to dopaquinone. The possible role of dopaquinone, and other L-DOPA oxidation products, in enhancing the cellular antioxidant defence mechanisms is discussed. 相似文献
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L-DOPA, also known as Levodopa or L-3,4-dihydroxyphenylalanine, is a non-standard amino acid, and the gold standard drug for the treatment for Parkinson's Disease (PD). Recently, a gene encoding the enzyme that is responsible for its synthesis, as a precursor of the coloured pigment group betalains, was identified in beetroot, BvCYP76AD6. We have engineered tomato fruit enriched in L-DOPA through overexpression of BvCYP76AD6 in a fruit specific manner. Analysis of the transgenic fruit revealed the feasibility of accumulating L-DOPA in a non-naturally betalain-producing plant. Fruit accumulating L-DOPA also showed major effects on the fruit metabolome. Some of these changes included elevation of amino acids levels, changes in the levels of intermediates of the TCA and glycolysis pathways and reductions in the levels of phenolic compounds and nitrogen-containing specialised metabolites. Furthermore, we were able to increase the L-DOPA levels further by elevating the expression of the metabolic master regulator, MYB12, specifically in tomato fruit, together with BvCYP76AD6. Our study elucidated new roles for L-DOPA in plants, because it impacted fruit quality parameters including antioxidant capacity and firmness. The L-DOPA levels achieved in tomato fruit were comparable to the levels in other non-seed organs of L-DOPA - accumulating plants, offering an opportunity to develop new biological sources of L-DOPA by widening the repertoire of L-DOPA-accumulating plants. These tomato fruit could be used as an alternative source of this important pharmaceutical. 相似文献
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The sound or ‘buzzing response’ from groups of fifteen worker honey bees, Apis mellifera L., to the presentation of isopentyl acetate, an alarm pheromone component, was recorded through a microphone connected via a digital–analogue converter into a computer. The effects of ingested biogenic amine precursors 5-hydroxytryptophan, L-DOPA and tryptophan were tested on three variables measurable from the sound traces: onset of the buzzing response after presentation of the pheromone stimulus, the duration of the buzzing event, and the maximal sound frequency produced during the buzzing event. Bees fed high doses of 5-hydroxytrytophan were found to react significantly more slowly and with a significantly lower maximum frequency than bees that were only fed sucrose controls. Bees fed DOPA were no different from controls for any of the variables measured, and bees fed tryptophan were so hyperactive that reliable responses to the presentation of alarm pheromone could not be made. Finally, the brains of worker bees fed these different precursors were examined for content of various neurochemicals. Bees fed 5-hydroxytryptophan were found to have dose-dependent elevations of both 5-hydroxytryptophan and serotonin within their brains. Bees fed tryptophan were found to have dose-dependent elevations of tryptophan and kynurenine in the brain but no change in brain serotonin. Bees fed DOPA had dose-dependent increases in DOPA and dopamine levels within their brains. These results suggest that the hyperactive condition results from kynurenine metabolism, and the reduced response to alarm pheromone is related to serotonin metabolism. 相似文献