排序方式: 共有26条查询结果,搜索用时 15 毫秒
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J. T. A. Leuschner D. R. Wing Dr. D. J. Harvey G. A. Brent C. E. Dempsey A. Watts W. D. M. Paton 《Cellular and molecular life sciences : CMLS》1984,40(8):866-868
Summary
1-Tetrahydrocannabinol (
1-THC) has been quantified directly in erythrocyte membranes from drug-treated mice using gas chromatography/mass spectrometry. Concentrations of approximately 6 ng
1-THC/mg membrane protein (10–5 M) were found when effects of the drug on behavior were prevalent. At these concentrations the drug produced a decrease in membrane order as measured by ESR.This work was supported by grants from the Medical Research Council, the Wellcome Trust and the E. P. Abraham Cephalosporin Trust 相似文献
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The primate amygdala represents the positive and negative value of visual stimuli during learning 总被引:1,自引:0,他引:1
Visual stimuli can acquire positive or negative value through their association with rewards and punishments, a process called reinforcement learning. Although we now know a great deal about how the brain analyses visual information, we know little about how visual representations become linked with values. To study this process, we turned to the amygdala, a brain structure implicated in reinforcement learning. We recorded the activity of individual amygdala neurons in monkeys while abstract images acquired either positive or negative value through conditioning. After monkeys had learned the initial associations, we reversed image value assignments. We examined neural responses in relation to these reversals in order to estimate the relative contribution to neural activity of the sensory properties of images and their conditioned values. Here we show that changes in the values of images modulate neural activity, and that this modulation occurs rapidly enough to account for, and correlates with, monkeys' learning. Furthermore, distinct populations of neurons encode the positive and negative values of visual stimuli. Behavioural and physiological responses to visual stimuli may therefore be based in part on the plastic representation of value provided by the amygdala. 相似文献
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Preferential germline mutation of the paternal allele in retinoblastoma 总被引:19,自引:0,他引:19
X P Zhu J M Dunn R A Phillips A D Goddard K E Paton A Becker B L Gallie 《Nature》1989,340(6231):312-313
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McCarroll L Paton MG Karunaratne SH Jayasuryia HT Kalpage KS Hemingway J 《Nature》2000,407(6807):961-962
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Paton AW Beddoe T Thorpe CM Whisstock JC Wilce MC Rossjohn J Talbot UM Paton JC 《Nature》2006,443(7111):548-552
AB5 toxins are produced by pathogenic bacteria and consist of enzymatic A subunits that corrupt essential eukaryotic cell functions, and pentameric B subunits that mediate uptake into the target cell. AB5 toxins include the Shiga, cholera and pertussis toxins and a recently discovered fourth family, subtilase cytotoxin, which is produced by certain Shiga toxigenic strains of Escherichia coli. Here we show that the extreme cytotoxicity of this toxin for eukaryotic cells is due to a specific single-site cleavage of the essential endoplasmic reticulum chaperone BiP/GRP78. The A subunit is a subtilase-like serine protease; structural studies revealed an unusually deep active-site cleft, which accounts for its exquisite substrate specificity. A single amino-acid substitution in the BiP target site prevented cleavage, and co-expression of this resistant protein protected transfected cells against the toxin. BiP is a master regulator of endoplasmic reticulum function, and its cleavage by subtilase cytotoxin represents a previously unknown trigger for cell death. 相似文献
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D. M. Paton 《Cellular and molecular life sciences : CMLS》1972,28(10):1191-1192
Zusammenfassung Es wurde die Wirkung von Lokalanästhetika auf die Anhäufung von [3H]-Metaraminol im Vorhofmuskel und Vas deferens des Kaninchens untersucht. Die von Kokain hervorgerufene Hemmung der [3H]-Metaraminol-Akkumulation ist mindestens hundertmal stärker als diejenige nach Procain, Prilocain und Lidocain.
Supported by a grant-in-aid from the Medical Research Council of Canada. The author is indebted to Astra Pharmaceuticals (Canada) Ltd. for supplies of lidocaine hydrochloride and prilocaine hydrochloride. 相似文献
Supported by a grant-in-aid from the Medical Research Council of Canada. The author is indebted to Astra Pharmaceuticals (Canada) Ltd. for supplies of lidocaine hydrochloride and prilocaine hydrochloride. 相似文献
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Effect of local anaesthetics on the accumulation of ( 3 H)-metaraminol by rabbit atria and vasa deferentia 总被引:1,自引:0,他引:1
D M Paton 《Experientia》1972,28(10):1191-1192
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In this paper, we examine a relatively novel form of gambling, spread (or index) betting that overlaps with practices in conventional financial markets. In this form of betting, a number of bookmakers quote bid–offer spreads about the result of some future event. Bettors may buy (sell) at the top (bottom) end of a spread. We hypothesize that the existence of an outlying spread may provide uninformed traders with forecasting information that can be used to develop improved trading strategies. Using data from a popular spread betting market in the United Kingdom, we find that the price obtaining at the market mid‐point does indeed provide a better forecast of asset values than that implied in the outlying spread. We further show that this information can be used to develop trading strategies leading to returns that are consistently positive and superior to those from noise trading. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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