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1.
以黑松花粉粒为研究材料,经过离子注入后对其细胞内的超氧阴离子自由基(O-2·)、丙二醛(MDA)含量、细胞膜透性和抗氧化酶(SOD、POD和CAT)活性的动态变化进行了检测.研究结果表明,氮离子注入对花粉粒内O-2·的产生速率、MDA含量、SOD、POD和CAT的活性均有明显的影响.随着离子注入剂量的增加,在花粉粒内O-2·的产生速率会持续加快;MDA的含量会相应增多;花粉粒细胞膜的伤害度表现出持续加重;SOD的活性呈现出先增加后降低的变化趋势;POD和CAT活性会持续降低.  相似文献   

2.
以不同浓度O,O-二甲基-α-[2,4-二氯苯氧丙酰氧基]丙基膦酸酯处理绿豆幼根,其过氧化物酶(POD)、超氧化物歧化酶(SOD)活性及其同工酶均发生相应变化,高浓度HJCE对POD和SOD均有较强的抑制作用,低浓度则对其抑制较弱或有一定的激活作用.同时,不同浓度的HJCE对绿豆幼根细胞相对存活率也有相似的影响.  相似文献   

3.
超氧物歧化酶(SOD)是广泛存在于需氧和耐氧生物机体内的金属酶,按其金属辅基成分可分为Mn-SOD、Fe-SOD和Cu·Zn-SOD三种类型.近期又发现Mn-SOD与Fe-SOD的杂合型。大量研究证实,不少疾病的起因均与自由基有关,而SOD能清除超氧阴离子(O_2~((?))),在预防衰老、抗辐射损伤、以及治疗肿瘤和炎症等方面有一定的  相似文献   

4.
对圆叶决明(Chamaecristarotundifolia)牧草CPI86134品系苗期进行15、10、5、0℃的低温胁迫,以25℃胁迫为对照.结果表明:随低温胁迫强度的提高和胁迫时间的延长,植株体内O-·2净产生速率增加;同时植株体内活性氧清除酶SOD、POD、AsAPOD的活性在0~48h胁迫时间之内以较快的速率提高,48h之后提高速率趋缓.其中冷害温度0℃分别胁迫6、12、18、24h后,叶片光合色素含量较对照(25℃)下降21.89%、26.04%、28.16%、29.31%,可溶性蛋白质含量和O-·2净产生速率随胁迫时间延长而提高,活性氧清除酶SOD的活性随胁迫时间延长先上升而后下降.在胁迫前施Ca2 处理可明显降低叶片O-·2净产生速率和电解质渗透率,同时提高了光合色素含量和活性氧清除酶SOD活性,其中以0.5mmol/L浓度的CaCl2处理效果为最佳,说明Ca2 对低温胁迫下圆叶决明的膜结构起有效的保护作用.  相似文献   

5.
近年来发现一些细菌可在无光好氧条件下产生胞外活性氧,但对该过程影响因素等特性的研究未见报道.基于此,考察了无光好氧环境中,基质和有机污染物对海洋细菌产胞外H2O2和O-2的影响.结果表明,菌株在蛋白胨和牛肉膏培养基中均能产生胞外H2O2和O-2.胞外H2O2浓度与菌株生长期有关;添加200 mg/L布洛芬能提高体系H2O2浓度.其次,产胞外O-2能力也与菌株生长期有关,对数期最强,稳定期最弱.在相同浓度下,牛肉膏体系产胞外O-2的能力强于蛋白胨体系.  相似文献   

6.
为了探讨龙眼多糖抗运动性疲劳的作用及其抗氧化调节机制,本文以小鼠作为实验对象,观察小鼠负重力竭游泳时龙眼多糖抗疲劳作用。通过紫外分光光度法,检测龙眼多糖对超氧阴离子(O-2·)和羟自由基(·OH)的清除作用;测定小鼠游泳后血液中丙二醛(MDA)含量、尿素氮(BUN)含量、乳酸脱氢酶(LDH)活性、超氧化物歧化酶(SOD)活性、乳酸变化等。结果表明:龙眼多糖能明显延长小鼠负重游泳时间(P0.05),减少小鼠尿素氮的产生(P0.05)以及乳酸含量(P0.05)和丙二醛(MDA)含量(P0.05),增加乳酸脱氢酶(LDH)(P0.05)和超氧化物歧化酶(SOD)(P0.05)的活性。龙眼多糖对羟自由基(·OH)有较强的清除作用,对超氧阴离子自由基(O-2·)的清除作用较小,可见,龙眼多糖具有良好的抗疲劳作用。  相似文献   

7.
通过研究3-(2-羟基-4-甲氧苯基)-4-(3-胺基-4-甲氧苯基)吡唑(HAMP)对超氧自由基(O-·2)和1,1-二苯基-2-苦苯肼自由基(DPPH·)的清除能力、还原力大小、Fe2+诱导的脂质过氧化反应和β-胡萝卜紊/亚油酸自氧化体系的抑制作用,对其体外抗氧化能力进行了评价.结果表明,HAMP对O-·2有较强清除能力,且抗脂质过氧化作用明显.说明HAMP可以作为抗氧化剂使用.  相似文献   

8.
解析了 2 ,9-二 ( n-2′,5′-二氮杂庚基 ) -1 ,1 0 -菲罗啉镍 ( )配合物的晶体结构 ,晶体属于单斜晶系 ,空间群为 P2 ( 1 ) /n,a=1 .2 5 1 0 ( 4) nm,b=1 .3 5 0 1 ( 5 ) nm,c=1 .6849( 5 ) nm,β=1 0 6.5 67( 6)°,V=2 .72 77( 1 6)nm3,Z=4,镍 ( )离子与配体的六个氮原子同时配位 ,形成变形八面体构型 ,Cl O- 4离子的氧原子与邻近的仲胺氮原子上的氢原子之间存在分子间氢键作用 .用紫外 -可见分光光度计研究了其与 DNA的相互使用 ,采用改进的邻苯三酚自氧化法研究了其对超氧阴离子自由基 O- .2 的抑制作用 ,结果表明该配合物能以插入模式与 DNA发生作用 ,并能有效地抑制超氧阴离子自由基 O- .2 的生成  相似文献   

9.
超氧化物歧化酶(Superoxide Dismutase简称SOD)是催化超氧阴离子自由基(O_2~((?)))发生歧化反应的一类金属酶。由于超氧阴离子自由基(O_2~((?)))对机体有损害,SOD对机体就起到了一种保护作用。据报道,SOD对超氧自由基引起的各种疾病如肿瘤、红斑狼疮、皮肌炎等都有一定的疗效,SOD作为植物抗逆剂、人体抗衰老剂,在临  相似文献   

10.
用常规TGA(程序升温热重分析)法间接表征了催化剂CaTi0.9Li0.1O3-δ晶格中的氧空位,关联了氧空位、可活动氧量与催化剂的乙烷氧化脱氢(ODHE)反应的催化性能,提出了乙烷在该类催化剂上氧化脱氢的选择性氧物种为873~1023 K的温度范围内脱附的所谓可活动氧(O-, O2-, O2-2简写为Oδ-).利用O2-TPD-MS鉴定了TGA结果,证明该法简便、实用、可靠.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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