196 research outputs found

    Effects of Exogenous Nitric Oxide Donor SNP on Lipid Peroxidation Caused by Selenium in Rice Seedlings

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    通讯作者(Corresponding author): 郑海雷, E-mail: [email protected] 第一作者联系方式: E-mail: [email protected], Tel: 15971698508[中文文摘]一氧化氮(nitric oxide,NO)是植物中一种重要的信号分子,在诱导种子萌发,影响植物生长发育,促进植物细胞衰亡等方面发挥着重要作用。然而对于外源NO是否参与了Se诱导的脂质过氧化调节过程仍不为人知。我们研究了0.2μmol L-1和20μmol L-1 Na2SeO3及一氧化氮供体硝普钠(sodium nitroprusside,SNP)处理对水稻叶片叶绿素、H2O2和硫代巴比妥酸反应产物(thiobarbituric acid reactive substances,TBARS)含量,愈创木酚过氧化物酶(guaiacol peroxidase,GPX)、超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)以及抗坏血酸过氧化物酶(ascorbate peroxidase,APX)活性等生理生化指标的影响。结果表明,1μmol L-1 SNP处理促进GPX、APX和CAT活性,缓解膜脂过氧化,降低TBARS含量;显著提高0.2μmol L-1 Na2SeO3处理下水稻叶片中叶绿素含量。在20μmol L-1 Na2SeO3处理下,外加1μmol L-1 SNP更加显著促进GPX和CAT活性,与此同时明显降低20μmol L-1 Na2SeO3处理引起的H2O2含量上升,并降低TBARS含量。NO对植物中由Se引起的脂质过氧化具有调节作用。[英文文摘]Nitric oxide (NO) is a bioactive molecule that has been suggested to act as a signaling molecular in plants. It induces germination, affects plant growth and development, and promotes plant cell death. NO is also involved in plant response to heat,salinity, ultraviolet-B, and heavy metal stresses. It is known that some effects of NO may relate to the regulation of reactive oxygen species (ROS) metabolism by means of affecting activities of catalase (CAT) with hemachrome iron, and/or guaiacol peroxidase (GPX) with none-hemachrome iron. However, whether NO regulates lipid peroxidation in rice seedlings induced by selenium is not yet understood. In this article, we reported some regulative effects of exogenous nitric oxide donor SNP on oxidative stresses induced by selenium in rice seedlings. The contents of chlorophyll, H2O2, TBARS and the activities of GPX, superoxide dismutase (SOD), CAT and ascorbate peroxidase (APX) in rice seedlings treated with a varying concentrations of selenium and 1 μmol L−1 SNP were investigated. The results showed that the content of chlorophyll increased by treatment with SNP in 0.2 μmol L−1 Na2SeO3 group. SNP alleviated significantly the lipid peroxidation in rice seedlings via promoting GPX, APX and CAT activities in rice leaf. In 20 μmol L−1 Na2SeO3 treated rice seedlings, SNP alleviated significantly TBARS content and the increase of H2O2 content that resulted from high selenium stress via promoting GPX, especially APX and CAT activities. Taken together, our results suggested that NO regulates lipid peroxidation caused by selenium in rice seedlings.国家自然科学基金项目(30670317);湖北省教育厅中青年人才项目(Q20092901);国家民委科研项目(09HB02);湖北民族学院博士启动基金项目,湖北民族学院校内青年科研项目(MYQ2006032)资

    Experimental study on reperfusion of intraocular lens

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    作者简介: 祁明信, 男, 1945 年7 月 出生, 教授、主任医师、博士研究生 导师, 主要从事白内障的基础与临 床研究。联系电话: 0591-83570887; E-mail:qihuang@netease. com 通讯作者: 黄秀榕,E-mail:[email protected][中文文摘]目的开展晶状体再灌注的离体和动物实验研究,并对再灌注人工晶状体技术进行评价。方法采用新鲜离体幼兔眼、离体猪眼、新西兰白兔眼,应用自行研制的人工晶状体材料,进行以下实验:(1)体外固化实验;(2)晶状体前囊膜微型撕囊及其稳固性实验;(3)经微型前囊膜开口超声乳化吸出晶状体内容物实验;(4)活的新西兰白兔眼内人工晶状体再灌注实验。结果(1)按硅酮聚合物与固化剂50:1的比例可获得柔软、弹性好、固化时间短(完全固化时间为60min)的注入材料;(2)晶状体前囊膜1.8~2.0mm的连续环形撕囊口具有较好的稳定性,可经该微型开口吸出晶状体内容物并灌注材料;(3)超声能量18%、流量25mL·min-1、负压120mmHg(1kPa=7.5mmHg)为晶状体内容物经微型前囊膜开口吸出的最佳条件;(4)注入灌注材料后可形成由晶状体囊膜包裹的、置换原晶状体皮质和核的、新的再灌注人工晶状体。结论采用再灌注人工晶状体的方法可进行新型人工晶状体再灌注,可为治疗白内障和老视提供参考。[英文文摘]Objective To carry out the experimental study on reperfusion of intraocular lens(IOLs) in vitro or in animal,and to assess the technique of IOLs reperfusion.Methods The following experiments were performed by using self-developed materials in fresh rabbit eyes and pig eyes in vitro,as well as in eyes of alive New-Zea-land rabbits:(1)Solidification study of self-developed material in vitro;(2)Continuous circular capsulorhexis(CCC) in anterior capsule of lens and its stability;(3)Draw of lens contents via phaco through mini-CCC;(4)IOLs ref illing in the eyes of alive New-Zea land rabbits. Results(1) Thematerialwhich was soft, springy and short-term solidification(full solidification time was 60 minutes) were obtained in certain proportion of geland solidified agent(50:1) in vitro; ( 2)The CCC in anterior capsule of lens with 1.8-2.0 mm diameter had very good stability. The lens contents were drawn and the materialwere refilled through themini-CCC; (3) The best conditions of drawing out lens contents through m ini-CCC were phaco energy 18% , flow 25 mL·min- 1, and negative pressure 120 mmH g (1kPa=7.5 mmHg);(4) The new refilled IOLs, which were wrapped by capsule of lens and were replaced original cortex and nucleus of lens, were obtained after thematerial refillied. Conc lusion. New IOLs are refilled through this method, which can prov ide reference for the treatment of cataract and presbyopia.福建省科技三项费用;教育厅重点资助项目基金资助(编号:K98041

    光学碱度及其在冶金中的应用

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    光学碱度的概念现已广泛用来解释和预测炉渣的化学性质,光学碱度利用探针离子的信息表示炉渣中的相对“自由”氧离子,是一种表达炉渣碱度的有效方法,炉渣的光学碱度即可通过测量而得到,也可由炉渣的化学成分计算出来,很多结果表明,在炼钢的渣剂控制模型中,利用不学碱度比一般碱度更能可靠的控制冶炼绺的化学成分;在钢包和中间包利用光学碱度的概念也有 地控制钢中的残余元素;也可以用来建立一些元素渣--金属平衡时的计算公式,本文系统介绍了光学碱度的概念,讨论和评价了其在冶金中的应用

    光学碱度及其在冶金中的应用

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    光学碱度的概念现已广泛用来解释和预测炉渣的化学性质.光学碱度利用探针离子的信息表示炉渣中的相对“自由”氧离子,是一种表达炉渣碱度的有效方法,炉渣的光学碱度即可通过测量而得到,也可由炉渣的化学成分计算出来.很多结果表明,在炼钢的渣剂控制模型中,利用光学碱度比一般碱度更能可靠地控制冶炼终点的化学成分;在钢包和中间包利用光学碱度的概念也有助于控制钢中的残余元素;也可以用来建立一些元素渣—金属平衡时的计算公式.本文系统介绍了光学碱度的概念,讨论和评价了其在冶金中的应用

    关于用硅探头快速测定铁水硅含量的问题

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    对生产高质量钢或其它金属来讲,快速测量金属熔池中的成分对控制冶炼、精炼和浇铸是十分重要的,开发电化学探头对完成这一任务具有实际意义.要生产高质量钢就要进行预处理,因为已经证明要进行预脱磷的铁水中硅含量应≤0.1wt%,而一般的炼铁工艺所生产的铁水硅含量都≥0.1wt%,所以铁水有效预处理的先决条件是先进行脱硅处理.而快速测量硅含量对控制铁水沟和运铁罐中的硅含量是十分有用的,所以在炼钢和炼铁生产中,在线分析硅含量不仅对高炉操作,而且对铁水预处理和电炉钢硅的合金化都有作用. 本文给出了近年来所设计的电化学硅探头的类型,根据测得电动势的响应时间和所能维持稳定电动势的时间对各种硅探头的优缺点进行了总结,预测了今后硅探头的发展方向

    固体电解质及其在炼钢中的应用

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    本文针对固体电解质定氧在我同钢厂中还不十分普及的情况,系统总结了固体电解质定氧探头中的参比电极形式、参比电极的比例、电极引线等因素,利用氧探头在炼钢中的实测数据分析了炼钢过程中的氧变化

    论炼钢过程中的泡沫化和乳化现象

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    以平炉和转炉为例简要地讨论了乳化和泡沫化的形成与破坏机理,使冶金工作者更加深刻地理解乳化和泡沫化现象,以便利用它们更平稳地进行冶炼操作

    CaO-MgO-FeO-Fe_2O_3-SiO_2炼钢渣系磷分配比的热力学模型

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    基于炉渣离子-分子共存理论(IMCT)建立了CaO-MgO-FeO-Fe_2O_3-SiO_2渣系的磷分配比预报模型,即IMCT-L_P模型。比较了该渣系在1823~1873 K时实测的磷分配比、IMCT-L_P模型预报的磷分配比及其他6种磷分配比模型的计算结果。与实测值和其他磷分配比模型预报结果相比,由IMCT-L_P模型预报的CaO-MgO-FeO-Fe_2O_3-SiO_2渣系的磷分配比更精确。本文建立的IMCT-L_P模型不仅可计算该渣系的磷分配比,而且可计算该渣系中碱性离子对(Ca~(2+)+O_2~-)、(Mg~(2+)+O_2~-)和(Fe~(2+)+O_2~-)各自的磷分配比
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