共查询到20条相似文献，搜索用时 156 毫秒
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对大鼠分别进行80 dB和100 dB的噪声刺激,并在第1、5、10、15和20 d测定大鼠血浆中有关激素的含量。结果表明:噪声应激引起大鼠血浆中的皮质醇、去甲肾上腺素、肾上腺素、多巴胺及血管紧张素Ⅱ含量明显升高,特别是肾上腺素含量比对照组提高2.5倍。说明噪声应激不仅使下丘脑-垂体- 肾上腺系统、交感神经-肾上腺髓质系统这两条经典应激途径活动加强,而且还有海马与蓝斑-去甲肾上腺素系统、杏仁核促肾上腺皮质激素释放激素神经元和肾素-血管紧张素系统的参与,使“应激系统”的活动加强。这对应激作出生理反应具有重要意义,但若长期维持,最终导致“应激综合征”或生理心理疾病的发生。 相似文献
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《科学中国人》2021,(12)
正首个用于AML分化治疗的CDK2选择性降解剂的发现清华大学饶燏教授和浙江大学应美丹教授等合作,在CDK2降解剂设计与应用方面取得突破。相关成果发表于Nature Chemical Biology。周期蛋白依赖性激酶(CDK)是一组丝氨酸/苏氨酸蛋白激酶,CDK2敲降可诱导AML(白血病)细胞产生分化。PROTAC技术是一种利用小分子诱导靶蛋白泛素化,利用泛素化蛋白酶体途径实现靶向蛋白敲降的技术。科学家开发了一类CDK2选择性降解剂,并初步研究了该分子的安全性和有效性。同时,他们将这项新的发现应用于AML分化治疗领域,为AML治疗提供了一种潜在的高效、低毒的新型治疗方案。除AML治疗外,该类降解剂或可在CDK2相关的其他疾病治疗领域也发挥重要功能。 相似文献
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<正>MuRF1和MAFbx是与骨骼肌蛋白分解代谢关系最为密切的泛素蛋白连接酶,是骨骼肌蛋白质降解的标志。目前,有关运动对骨骼肌蛋白质降解的研究较少,本文就MuRF1和MAFbx的结构、作用,以及运动过程中MuRF1mRNA和MAFbxmRNA表达量的变化进行综述,探讨运动过程中骨骼肌蛋白质的降解。 相似文献
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正MuRF1和MAFbx是与骨骼肌蛋白分解代谢关系最为密切的泛素蛋白连接酶,是骨骼肌蛋白质降解的标志。目前,有关运动对骨骼肌蛋白质降解的研究较少,本文就MuRF1和MAFbx的结构、作用,以及运动过程中MuRF1mRNA和MAFbxmRNA表达量的变化进行综述,探讨运动过程中骨骼肌蛋白质的降解。 相似文献
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热休克蛋白的研究进展及其应用 总被引：7，自引：0，他引：7
在不利的环境中，各种有机体都有其共同对应的分子反应，即正常基因的表达抑制和一组特殊基因－热休克基因的激活和表达，并导致热休克蛋白的大量产生。热休克蛋白主要作为分了伴侣而参与蛋白的折叠、转运及组装等过程，并能恢复或加速清除细胞内已变性的蛋白质而稳定细胞结构，使细胞产生热耐受。随着对热休克蛋白研究的不断深入，其在生物工程、医学和遗传育种等方面的应用前景十分广阔。 相似文献
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General physiology,experimental psychology,and evolutionism. Unicellular organisms as objects of psychophysiological research, 1877-1918 总被引：1，自引：0，他引：1
Schloegel JJ Schmidgen H 《Isis; an international review devoted to the history of science and its cultural influences》2002,93(4):614-645
This essay aims to shed new light on the relations between physiology and psychology in the late nineteenth and early twentieth centuries by focusing on the use of unicellular organisms as research objects during that period. Within the frameworks of evolutionism and monism advocated by Ernst Haeckel, protozoa were perceived as objects situated at the borders between organism and cell and individual and society. Scholars such as Max Verworn, Alfred Binet, and Herbert Spencer Jennings were provoked by these organisms to undertake experimental investigations situated between general physiology and psychology that differed from the physiological psychology advocated by Wilhelm Wundt. Some of these investigations sought to locate psychological properties in the molecular structure of protoplasm; others stressed the existence of organic and psychological individuality in protozoa. In the following decades, leading philosophers such as Friedrich Nietzsche, Charles Sanders Peirce, and Henri Bergson, as well as psychological researchers like Sigmund Freud, integrated the results of these investigations into their reflections on such problems as the nature of the will, the structure of the ego, and the holistic nature of the reactions of organisms to their environment. 相似文献
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报道一个催化动力学分析专家系统(CKAES),该系统可完成催化动力学分析指示反应体系的确定,测定某元素的反应体系的搜索及有机分子结构显示等.系统主要包括知识库、推理机构、知识获取子系统、解释子系统、有机试剂分子结构显示、动态数据库和理论学习等七大模块.系统采用产生式规则的知识表达方式,正反双向推理技术。知识库与程序相互独立,便于知识库韵扩充与修改。系统还包括浏览知识库、编辑新老文件、文件存取、同DOS交互等多种功能.CKAES使用TurboPROLOG语言编程,经编译生成可执行文件,在IBM PC/XT及其兼容机实现. 相似文献
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《国家科学评论(英文版)》2014,(1)
Apoptosome and inlammasome are multimeric protein complexes that mediate the activation of speciic caspases at the onset of apoptosis and inlammation.he central component of apoptosome or inlammasome is a tripartite scafold protein,exempliied by Apaf-1 and NLRC4,which contains an amino-terminal homotypic interaction motif,a central nucleotide-binding oligomerization domain and a carboxyl-terminal ligand-sensing domain.In the absence of death cue or an inlammatory signal,Apaf-1 or NLRC4 exists in an auto-inhibited,monomeric state,which is stabilized by adenosine diphosphate(ADP).Binding to an apoptosis-or inlammation-inducing ligand,together with replacement of ADP by adenosine triphosphate(ATP),results in the formation of a multimeric apoptosome or inlammasome.he assembled apoptosome and inlammasome serve as dedicated machineries to facilitate the activation of speciic caspases.In this review,we describe the structure and functional mechanisms of mammalian inlammasome and apoptosomes from three representative organisms.Emphasis is placed on the molecular mechanism of caspase activation and the shared features of apoptosomes and inlammasomes. 相似文献
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Contrary to what Jacques Monod affirmed in the 1960s, it is now known that what is true of the bacterium is not true of the elephant. In particular, it was discovered in 1977 that the genes of the higher organisms are split into segments, instead of being continuous as is the case with, for example, Escherichia coli. What is the significance of this split structure and how do organisms manage to gather together the useful parts of their genes and to eliminate those which are surplus? This article reviews what is already certain in this field and comments on the most recent prospects opened up by the discovery of genes ‘in pieces’. 相似文献
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《中国科学院院刊(英文版)》2009,23(1):14-15
Gene, the very basic unit of heredity in a living organism, has long heldthe limelight in modern biological studies. One fundamental truth revealed by scientists is the origination of new genes is a driving force behind evolutionary innovation in all organisms. However, except a few case studies, they are not very clear how the novel genes have been created in Nature. Now, with the help of molecular biology, scholars strive to understand the mechanisms underlying their origination. 相似文献
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共价键理论是化学学习中物质结构的重要内容,是价键理论的重要组成部分。非化学专业的学生由于多方面的原因,目前对于共价键理论的学习都只侧重于结论,对于其中的原理比较模糊。尤其是电子轨道方向性的来源,电子波函数最大重叠原理与成键的关系,σ,π成键的描述和杂化轨道的轨道处理问题与分子构型的关系。从原子分子物理的角度对共价键理论系统的学习可以对这些问题进行解释。 相似文献
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The way in which cells in multicellular organisms communicate and inform each other of their presence and relative position is an intriguing but mysterious problem. The form of communication used during the phase of aggregation in the cellular slime moulds represents a particularly amenable system for study. When these organisms run short of nutrients, some of the cells of the amoebal population emit rhythmic pulses of cyclic adenosine monophosphate. These chemical signals are slowly relayed to all the other amoebae within range and bring about an ordered migration of them towards the pulsating centre and the triggering of cellular development. 相似文献
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有害生物的生态调控一直是作物病虫害预防与治理的重要前沿科技领域。目前有害生物生态调控研究已由单一的农田拓展到区域性农田景观的空间范围。研究区域性农田景观中格局特征和人类活动对病虫害和天敌种群动态影响,不仅在病虫害生物防治的实践中有重要意义,而且对于揭示人类活动对生物多样性结构与功能的影响,阐明区域性农田景观中生物多样性整合、维持机理有重大的理论意义。作物病虫害的导向性防控——生物间信息流与行为操纵,最终需要体现和落实在特定的地理区域空间范围内,参与到粮食作物生产与病虫害生态管理活动过程中。文章主要阐述区域性农田景观中格局特征与人类种植活动对昆虫的生态学效应,并提出构建基于区域性农田景观多元化的有害生物生态调控体系。 相似文献
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1．以两性物质例示化学分子的语境依赖性,并切入场有（Beinginfield）哲学和语境论哲学;2．布特列洛夫、凯库勒和范霍夫等人对“立体结构”概念之贡献,再结合刘易斯共价键理论,形成刚性化的经典分子结构模型;3．鲍林“共振论”：从刚性分子结构到动态分子结构的进步;4．分子结构：走向量子实体的语境实在论和整体论理解。 相似文献