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121.
122.
Chen KY  Zhu PH 《生理学报》1999,(2):153-160
用蛙胫前肌小束为材料, 研究了提高胞外钾[K+]O对咖啡因挛缩的作用.[K+]O从2 mmol/L提高到10或25 mmol/L, 由3 mmol/L咖啡因引起的挛缩明显增强.以PKC/PC (PKC和PC分别为在高钾和正常钾条件下的咖啡因挛缩)表示的咖啡因挛缩增强, 依赖[K+]O和高钾作用时间.随着10 mmol/L [K+]O作用时间延长, 直至10 min, 增强逐渐增加.但是, 25 mmol/L [K+]O作用1 min时增强达到最大, 然后下降到对照.PKC/PC变化时程不能用高钾引起的去极化解释, 而与由相似[K+]O引起的胞浆自由钙变化时程相符.提示, 至少在蛙骨骼肌, 高钾引起的咖啡因挛缩增强主要是由胞浆自由钙升高引起的.  相似文献   
123.
目的探讨进展期胃癌生长过程中p53基因表达与微血管密度和生物学行为之间的关系。方法搜集有随访资料的胃癌标本107例,用免疫组化对突变型p53和CD34作了标记,用原位杂交对野生型p53作了检测。结果突变型p53在肿瘤不同侵犯深度、不同生长方式、不同淋巴结转移状态以及预后方面,存在显著差异(P<0.05),突变型p53与微血管密度显著相关(P<0.05),而野生型p53则与突变型p53相反。结论突变型和野生型p53在肿瘤生长过程中的表达不同,说明p53的不同功能状态在肿瘤的发展过程中发挥重要作用。  相似文献   
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125.
In this paper, a new effective model is proposed to forecast how long the postoperative patients suffered from non-small cell lung cancer will survive. The new effective model which is based on the extreme learning machine (ELM) and principal component analysis (PCA) can forecast successfully the postoperative patients' survival time. The new model obtains better prediction accuracy and faster convergence rate which the model using backpropagation (BP) algorithm and the Levenberg-Marquardt (LM) algorithm to forecast the postoperative patients' survival time can not achieve. Finally, simulation results are given to verify the efficiency and effectiveness of our proposed new model.  相似文献   
126.
Based on eight years continuous observation and measurement on the ways and intensity of utilization of three fixed plots of the meadow of natural Aneurolepidium chinense in the Songnen Plain of China at definite stage of annual growth season the quantitative analysis on the relationship between the variations of fruit-bearing organic characters of A. chinense population and the climatic factors was investigated. Change of climate was one of the comprehensive factors which led to the variations of fruit-bearing organic characters of the population in different plots, but variations on the characters of the population among the plots and on the degree of correlation or functional relationships between the character and the climatic factor in different stages were only caused by the ways and intensity utilization. The characters of the spike organ were more affected by climatic factors in the stage of growth and development of the winterness plants of the population. There were universal ecological effects of time lap in the climatic factors.  相似文献   
127.
以人红细胞膜为材料,研究了甲基毒死蜱与膜上乙酰胆碱酯酶(AChE)的相互作用及其与膜脂的关系。结果显示,甲基毒死蜱对人红细胞膜AChE有明显的抑制作用,与膜温育30min,其半数抑制浓度约为0.10 mmol/L。动力学分析表明,其抑制作用为非竞争性。0.2%Triton X-100并不改变AChE对甲基毒死蜱的敏感性,亦即AChE上甲基毒死蜱的作用部位与其所处的脂质微环境无关。  相似文献   
128.
Song XM  Wang Y  Zhu Z  Li CY 《PloS one》2010,5(11):e15025
In V1 of cats and monkeys, activity of neurons evoked by stimuli within the receptive field can be modulated by stimuli in the extra-receptive field (ERF). This modulating effect can be suppressive (S-ERF) or facilitatory (F-ERF) and plays different roles in visual information processing. Little is known about the cellular bases underlying the different types of ERF modulating effects. Here, we focus on the morphological differences between the S-ERF and F-ERF neurons. Single unit activities were recorded from V1 of the cat. The ERF properties of each neuron were assessed by area-response functions using sinusoidal grating stimuli. On completion of the functional tests, the cells were injected intracellularly with biocytin. The labeled cells were reconstructed and morphologically characterized in terms of the ERF modulation effects. We show that the vast majority of S-ERF neurons and F-ERF neurons are pyramidal cells and that the two types of cells clearly differ in the size of the soma, in complexity of dendrite branching, in spine size and density, and in the range of innervations of the axon collaterals. We propose that different pyramidal cell phenotypes reflect a high degree of specificity of neuronal connections associated with different types of spatial modulation.  相似文献   
129.
Leaf morphology is an important agronomic trait in rice breeding. We isolated three allelic mutants of NARROW AND ROLLED LEAF 1 (nrl1) which showed phenotypes of reduced leaf width and semi-rolled leaves and different degrees of dwarfism. Microscopic analysis indicated that the nrl1-1 mutant had fewer longitudinal veins and smaller adaxial bulliform cells compared with the wild-type. The NRL1 gene was mapped to the chromosome 12 and encodes the cellulose synthase-like protein D4 (OsCslD4). Sequence analyses revealed single base substitutions in the three allelic mutants. Genetic complementation and over-expression of the OsCslD4 gene confirmed the identity of NRL1. The gene was expressed in all tested organs of rice at the heading stage and expression level was higher in vigorously growing organs, such as roots, sheaths and panicles than in elsewhere. In the mutant leaves, however, the expression level was lower than that in the wild-type. We conclude that OsCslD4 encoded by NRL1 plays a critical role in leaf morphogenesis and vegetative development in rice.  相似文献   
130.
对国内外有关社会等级形成原因、表现形式及功能的研究进行了综述。目前,多数对社会等级的研究集中在社会等级的表现形式和功能2个方面,而对社会等级形成原因的了解比较少,今后应加强此方面的研究,有利于对社会等级进化意义的深入理解。  相似文献   
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