共查询到20条相似文献，搜索用时 109 毫秒
1.
郑永裕 《漳州职业大学学报》2003,5(2):113-115
介绍自由基反应引起衰老的机理及抗自由基损害的人体防御功能。在人体新陈代谢过程中，不断产生自由基，自由基化学性质活泼，与细胞中的脂类、蛋白质和核酸发生反应，造成细胞结构、功能的破坏。当人体的抗氧化功能衰退时，这种损害加剧，经过一定时间的积累，细胞正常功能减退丧失，衰老就发生了。 相似文献
2.
刘尚旭 《重庆第二师范学院学报》1996,(4)
机体内自由基与细胞的衰老有着密切的联系,由自由基所引起的细胞衰老是机体衰老的重要因素之一,在衰老生化中有一定影响。本文从生物化学角度介绍机体内自由基的主要来源、性质、对机体的损伤与细胞衰老的关系以及抗衰老的生化机理。 相似文献
3.
自由基,超氧化物歧化酶（SOD）及抗衰老 总被引：2，自引：0，他引：2
自由基是一类含有一个不成对的电子的具有高度活性的物质，体内过多的自由工对机体具有损害作用并引起衰老，超氧化物歧化酶（ＳＯＤ）能有效地清除自由基，从而起到抗衰老的作用。 相似文献
4.
人的衰老与自由基 总被引：1，自引：0，他引：1
黄凤玲 《湘潭师范学院学报(社会科学版)》1996,(6)
衰老与自由基学说主要认为随着年龄增大的退行性变化是由于自由基的副作用引起。在正常情况下，机体内自由基的产生与消失是处于动态平衡的。当体内的自由基过剩时，细胞的生物大分子比学结构发生破坏性反应，损伤正常组织形态功能的完整性。当损伤程度超过修复或丧失其代偿能力时，组织器官的机能就逐步发生紊乱及障碍，表现出机体逐渐趋于衰老。 相似文献
5.
"有色"菜果与自由基 总被引：2，自引：0，他引：2
人体内过量的自由基会引起生命大分子的交联和脂褐素的累积、器官组织细胞的破坏与减少、免疫功能的降低，给我们的生命带来危害。我们可以从蔬菜、水果中补充抗氧化剂来清除体内过多的自由基，以保护人体细跑、组织、心脑血管循环系统等，从而达到抗癌及延缓衰老的目的。 相似文献
6.
郑永裕 《Journal of Zhangzhou Technical Institute》2003,5(2):113-115
介绍自由基反应引起衰老的机理及抗自由基损害的人体防御功能。在人体新陈代谢过程中,不断产生自由基,自由基化学性质活泼,与细胞中的脂类、蛋白质和核酸发生反应,造成细胞结构、功能的破坏。当人体的抗氧化功能衰退时,这种损害加剧,经过一定时间的积累,细胞正常功能减退丧失,衰老就发生了。 相似文献
8.
自由基导致细胞膜内的各种膜结构受到破坏，引发衰老，抗氧化物质有利于减少自由基的产生或加速其清除．有抗氧化、清除氧自由基作用的维生素可对抗人体衰老． 相似文献
10.
植物衰老机理研究进展 总被引：2，自引：0，他引：2
衰老是植物生长发育进程中的最后阶段,是一种基因编码的程序性事件,并且与自由基伤害有着密切的关系。本文介绍衰老的自由基理论和细胞程序性死亡理论及其研究现状与进展。 相似文献
11.
School disciplines,social representations,and the construction of the didactics of history,geography, and civics 总被引：1，自引：0，他引：1
The author presents a concept of the didactics of history, geography, and civics that seeks to link, through a single dynamic, the civic, political, and social goals of school knowledge with everyday classroom practice and pupils' learning. Two concepts occupy the heart of this construction: those of school disciplines and social representations. The concept of school disciplines addresses the fact that school knowledge is a creation of the school, designed to enable it to achieve the social goals it is assigned. A school discipline is thus a particular combination of goals, content (in the form of shared knowledge), methods, and practices. The concept of social representations is a tool serving to analyze knowledge as theories of the natural and social world, its production, and its reception by the different actors involved. 相似文献
12.
Jamel K. Donnor 《Peabody Journal of Education》2018,93(1):23-37
In this paper, I examine the use of litigation as a strategic tool of resistance for thwarting school desegregation. Utilizing Cowan v. Bolivar County Board of Education as a case study, I argue that, despite losing the constitutional right to racially segregate public schools according to an explicit white supremacist doctrine, whites in Bolivar County, Mississippi, were successful in stemming the impending tide of social change associated with school desegregation through litigation. Litigious resistance not only provided southern whites with a racially moderate epistemology for undermining school desegregation regionally, but their legal challenges to school desegregation also laid the groundwork for non-southern white animus toward all federal education policies that promoted racial inclusion. 相似文献
13.
14.
William DeGenaro 《Community College Journal of Research & Practice》2013,37(7):529-545
Community college practitioners frequently bemoan negative or stereotypical representations of community college students and community college life in general in the popular media. Saturday Night Live skits and satirical news reports in The Onion enjoy poking fun at community colleges, while mainstream news outlets often fail to challenge stereotypes of community colleges as lacking academic rigor. Those frustrated by these portrayals should know that the press overwhelmingly lauded 2 year colleges during the early decades of the “junior college” movement. Such reporting celebrated the new institutions' missions, and praised their speedy growth as components of public education. In fact, the press often implied that these new campuses reflected an inevitable step in the evolution of American higher education. This paper analyzes media reports about public 2 year colleges (at the time called junior colleges) published during the 1920s and 1930s. The term junior college is used in this historical review since the term was common during the era in question. 相似文献
15.
Yaroslav Senyshyn 《Interchange》1995,26(2):105-126
This paper is a critical evaluation of what is believed by the author to be Kierkegaard's subjective, ambivalent, and arbitrary stereotyping of women. In particular, the paper examines the Kierkegaardian notion of equality, essential feminine characteristics, and finitude. The result is an attempt to apply Kierkegaard's ideas to those issues pertaining to inequality in musical performance; as well, a plea is made for the demystification of the notion of woman as whore or Madonna. 相似文献
16.
ELIYAHU ROSENOW 《Journal of Philosophy of Education》1993,27(2):209-220
ABSTRACT An examination of contemporary publications in the philosophy of education reveals that the authority of the teacher is being eroded. As teachers derive their authority from the democratic state and its compulsory education laws, the undermining of their authority indicates the undermining of the authority of the democratic state and its laws. A comparison between Plato and Dewey from this point of view reveals that this state of affairs is the upshot of the collision between the principle of authority and the principle of liberty, and that this collision constitutes the basic problem of democracy as well as of education for democracy. The challenge to contemporary education is consequently that of exploring ways leading to the rehabilitation of the authority of the teacher. 相似文献
17.
Becky Francis Louise Archer Julie Moote Jen de Witt Lucy Yeomans 《British Journal of Sociology of Education》2017,38(8):1097-1110
Hyper-femininity and the construction of the ‘girly girl’ label have been documented widely, but there has been less attention to their content (or any distinctions between these constructs). Indeed, it can be argued that the content of femininity remains a controversial and somewhat under-researched topic in feminist scholarship. This is also the case in relation to science, which has been widely characterised as a masculine terrain, but there has been less attention to why femininity is excluded from/by science. This article attempts to unpick some of these issues, with a particular focus on the construct of the ‘girly girl’, in relation to access to science. Drawing on qualitative data from the Economic and Social Research Council-funded ASPIRES 2 project, we analyse the discourses used by young people and parents in discussion of ‘girly girls’ and physics. We show the misogynist and excluding discourses projected onto the ‘girly girl’, and indeed that are used to interpolate femininity more broadly. We found that in discussions of science and (hyper-)femininity, even potentially positive feminine attributes were denigrated. Hyper-femininity was produced as ‘more than lack’: vacuous, but also a risible presence. In reflecting on our findings we consider whether femininity may be more derided in some discursive contexts (e.g. science discourse) than others, and whether femininity can or should be conceived as more than lack. 相似文献
18.
借助功能语言学主位和主位推进模式有关理论来分析语篇的衔接、信息分布、连贯、语篇发展以及译者如何利用这些分析结果充分解读翻译源文,在以语篇为翻译单位时,采取何种相应的翻译对策,生成在功能和效果上与之相当的目的语语篇。 相似文献
19.
Maria Develaki 《Science & Education》2008,17(8-9):873-888
In view of the complex problems of this age, the question of the socio-ethical dimension of science acquires particular importance. We approach this matter from a philosophical and sociological standpoint, looking at such focal concerns as the motivation, purposes and methods of scientific activity, the ambivalence of scientific research and the concomitant risks, and the conflict between research freedom and external socio-political intervention. We then point out the impediments to the effectiveness of cross-disciplinary or broader meetings for addressing these complex problems and managing the associated risks, given the difficulty in communication between experts in different fields and non-experts, difficulties that education is challenged to help resolve. We find that the social necessity of informed decision-making on the basis of cross-disciplinary collaboration is reflected in the newer curricula, such as that of Greece, in aims like the acquisition of cross-subject knowledge and skills, and the ability to make decisions on controversial issues involving value conflicts. The interest and the reflections of the science education community in these matters increase its—traditionally limited—contribution to the theoretical debate on education and, by extension, the value of science education in the education system. 相似文献
20.
In the literature on the situated and distributed nature of cognition, the coordination of spatial organization and the structure of human practices and relations is accepted as a fact. To date, science educators have yet to build on such research. Drawing on an ethnographic study of high school students during an internship in a scientific research laboratory, which we understand as a “perspicuous setting” and a “smart setting,” in which otherwise invisible dimensions of human practices become evident, we analyze the relationship between spatial configurations of the setting and the nature and temporal organization of knowing and learning in science. Our analyses show that spatial aspects of the laboratory projectively organize how participants act and can serve as resources to help the novices to participate in difficult and unfamiliar tasks. First, existing spatial relations projectively organize the language involving interns and lab members. In particular, spatial relations projectively organize where and when pedagogical language should happen; and there are specific discursive mechanisms that produce cohesion in language across different places in the laboratory. Second, the spatial arrangements projectively organize the temporal dimensions of action. These findings allow science educators to think explicitly about organizing “smart contexts” that help learners participate in and learn complex scientific laboratory practices. 相似文献