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181.
L Le Bouffant C Izard H Daniel J P Henin J C Martin P Payen 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,284(11):983-986
When animals are exposed to cigarette smoke, the concentration of carbon monoxide in blood is rapidly increased, so that intensive inhalation tests cannot be carried out. A simple apparatus is described to expose Rats alternatively to cigarette smoke and to oxygen in order to reduce the concentration of carbon monoxide in the blood. This method makes it possible to increase the daily administration of smoke considerably; nevertheless, under such conditions, lung tumors were not observed. 相似文献
182.
本文提出了人口经济区域规划中的资源和经济发展分析模型.此模型由两个模型组成,第一个是采用AHP 决策方法的区域发展战略决策模型,第二个是在第一个模型基础上,引入可能度、满意度概念的经济发展平衡优化模型.通过这两个模型的计算,农业可以为地区未来人口、经济规划提供资源经济分析基础.本文最后给出了勉县,发展分析的实例. 相似文献
183.
R. Gheyouche A. Uzan G. Le Fur M. Corgier 《Cellular and molecular life sciences : CMLS》1981,37(5):492-493
Summary A decrease in the number of binding sites (Bmax) for [3H]ouabain was observed in the heart (37%) and the brain (22%) of spontaneously hypertensive rats (SHR) when compared with age-matched control Wistar Kyoto rats. No variation was detected in the affinity constant (KD). 相似文献
184.
L Le Goff M Beljanski 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1979,288(1):147-150
RNA-fragments U2 obtained by mild degradation with RNase U2 of ribosomal RNA containing A and G nucleotides in excess are capable of exhibiting either a stimulatory effect on the induction of Crown-gall tumors or an inhibitory action on their subsequent development. These different effects are dependent on the moment at which RNA-fragments were introduced into wounded Pea seedlings infected by Agrobacterium tumefaciens B6. The results obtained in vitro and in vivo suggest that an interaction between auxin and RNA-fragments U2 may take place, either increasing the tumor induction or inhibiting the proliferation of tumourous cells. 相似文献
185.
The role of platelet-activating factor in platelet aggregation. 总被引:21,自引:0,他引:21
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A number of proto-oncogenes have recently been localized to the chromosomal segments that are the breakpoints in the specific rearrangements noted in human malignant diseases. Moreover, rearranged forms of several proto-oncogenes have been identified in malignant cells; in several instances, the proto-oncogene has undergone an alteration as a result of a nonrandom chromosomal rearrangement. One proto-oncogene that has yet to be associated with human neoplastic disease is c-src, the cellular homologue of the transforming sequence of Rous sarcoma virus (RSV). By somatic cell hybridization, c-src has been mapped to chromosome 20, but its precise location was not determined. We have now mapped this gene by using in situ hybridization of the cloned human c-src probe to human mitotic chromosomes. We report here that the human genome contains two loci with strong homology to the coding regions of this oncogene, at 1p34-p36 and 20q12-q13. It is noteworthy that these chromosomal regions are frequently involved in the structural rearrangements observed in haematological malignant diseases. 相似文献
189.
H Simon L Stinus M Le Moal 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1980,290(3):255-258
The acquisition of the intravenous self-administration of d-amphetamine was studied after separate lesions of anterior raphe nuclei (dorsal or median). Every lever-press delivered 2.5 microliter of a d-amphetamine solution dosed at 7.5 microgram/kg. Lesion of anterior raphe nuclei produced an hyper-sensitivity to d-amphetamine as indicated by a dramatic increase in self-administration by experimental Rats compared to the controls. Moreover this enhanced self-administration behavior is observed with a low blood concentration of d-amphetamine. The greater increase was obtained for median raphe lesioned Rats. These effects are interpreted in terms of 5HT-DA balance and could provide an experimental model for neurobiological bases of drug addiction studies. 相似文献
190.