非生物胁迫下植物体内活性氧清除酶系统的研究进展

植物受到非生物胁迫时,细胞内活性氧的产生及其清除会失去平衡,活性氧过量积累会导致植物体内氧化胁迫。文章简要概述了在非生物胁迫下,植物体内产生的活性氧使植物体内细胞受到氧化胁迫危害,介绍了活性氧清除酶系统在非生物胁迫中的作用,该清除酶系统主要包括超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、脱氢抗坏血酸还原酶（DHR）、谷胱甘肽还原酶（GR）和谷胱甘肽过氧化物酶（GPX）。     

帕瑞昔布对过氧化氢诱导的原代星形胶质细胞氧化应激的保护作用（英文）

目的:评估帕瑞昔布对过氧化氢诱导的大鼠原代星形胶质细胞氧化应激状态的保护作用,并初步探讨其作用机制。创新点:首次在大鼠原代星形胶质细胞中证实帕瑞昔布对过氧化氢诱导的氧化应激具有保护作用,且此作用可能与Bax、Bcl-2和BDNF的失调有关。方法:设立如下四组对照:(1)阴性对照组;(2)100μmol/L H_2O_2处理组(处理时间为24 h);(3)80μmol/L帕瑞昔布处理组;(4)160μmol/L帕瑞昔布处理组(第三和第四组先用帕瑞昔布处理24 h,再用100μmol/L H_2O_2处理24 h)。用荧光显微镜观察星形胶质细胞的形态,用MTT法检测星形胶质细胞的存活率,用荧光探针二氯荧光黄双乙酸盐(DCDHF-DA)检测星形胶质细胞内氧自由基的含量,并用碘化丙啶(PI)染色检测细胞的凋亡状态。最后用反转录酶聚合酶链反应(RT-PCR)和蛋白质印迹(Western blot)检测Bax、Bcl-2和BDNF三种蛋白在4组中的表达水平。结论:H_2O_2处理可以导致星形胶质细胞的形态发生改变(图1)和存活率降低(图2),提高星形胶质细胞内的氧自由基水平(图3),同时诱导细胞凋亡(图4)。然而,所有这些变化都可以被帕瑞昔布逆转。此外,我们发现,Bax、Bcl-2和BDNF的表达水平在H_2O_2处理时失调,而在帕瑞昔布预处理时恢复正常。综上所述,帕瑞昔布对H_2O_2诱导的氧化应激具有保护作用。     

水分胁迫对植物活性氧代谢的影响

水分胁迫能够使植物细胞产生大量的活性氧,而植物体内的酶促和非酶促清除系统如不能及时地将其清除,活性氧的产生能力大于清除能力,就会使植物体内的活性氧代谢失调,对植物造成伤害.文中主要介绍了水分胁迫下植物体内活性氧自由基的产生、清除及其与抗旱性的关系,并就活性氧代谢的进一步研究提出了建议.     

氧化苦参碱对活化的小胶质细胞的抑制作用

目的:研究氧化苦参碱(OMT)对激活的小胶质细胞的作用及机制。方法:培养BV2小胶质细胞株,实验分为对照组(Con),细菌脂多糖(LPS)组,OMT实验组。应用western-blot检测OMT对LPS激活的BV2细胞HSP60的影响,ELISA检测OMT对HSP60和TNF-α释放的作用。结果:LPS组中HSP60的表达及HSP60、TNF-α的释放都比对照组显著增加,加入OMT后,这些因子的水平都明显降低。结论:OMT可能抑制通过HSP60信号通路降低炎症因子的产生而发挥神经保护作用。     

亨廷顿舞蹈症、氧化应激与胶质细胞

氧化应激的产生与胞浆内活性氧簇的升高密切相关,过多生成的活性氧簇能够造成脂质过氧化,损伤蛋白质甚至DNA,而这些物质的受损与疾病发生相关,尤其是神经退行性疾病.神经退行性疾病经常被描述为进行性的神经元丢失,伴随神经元或者胶质细胞中出现标志性寡聚体.在神经退行性疾病中,胶质细胞可能以一种抗氧化应激的方式在神经元功能维持以及生存上发挥重要作用.反之,神经元也能够通过不同途径反馈调节胶质细胞.该文主要探讨在亨廷顿舞蹈症中胶质细胞的特点和功能,阐明氧化应激与亨廷顿舞蹈症的关系,概括这三者之间的关系进而论证胶质细胞在亨廷顿舞蹈症中的抗氧化应激保护作用.     

一种化学发光新体系测定抗坏血酸的抗氧化性

基于过氧化氢与Co2 反应产生的羟基自由基(HO·)氧化鸟嘌呤产生化学发光这一现象,研究了抗坏血酸的抗氧化性能.实验结果表明,抗坏血酸能有效地清除羟自由基,对鸟嘌呤的氧化损伤具有保护作用.该发光体系将能被用于抗羟基自由基药物的筛选.     

右美沙芬对激活的小胶质细胞的抑制作用

目的:研究右美沙芬(DM)对激活的小胶质细胞的作用及热休克蛋白60(HSP60)在DM神经保护中的作用机制。方法:培养BV2小胶质细胞株,分为对照组,细菌脂多糖组,(LPS),实验组(DM)。Western-blot检测DM对LPS激活的BV2细胞HSP60和Caspase 3的影响,ELISA检测DM对HSP60释放的作用。结果:LPS组中HSP60和Caspase 3的表达及释放都比对照组显著增加,加入DM后,这些因子的水平都明显降低。结论:DM可能通过HSP60信号通路途径阻止小胶质细胞的凋亡而发挥神经保护作用。     

小鼠早期脓毒性脑病中小胶质细胞活化的探索研究

脓毒性脑病是决定脓毒症死亡率的关键因素。虽然脑中炎症反应与脓毒性脑病的发生相关,但其分子机制尚不清楚。本文针对早期脓毒性脑病中小胶质细胞是否活化进行探索性研究。采用盲肠结扎穿孔术(CLP)制备脓毒症小鼠模型,将小鼠大脑皮层样本经组织免疫荧光化学染色后,在激光共聚焦显微镜下观察小胶质细胞免疫荧光强度变化情况,并与假手术组对比,通过形态上的变化来确认小胶质细胞的活化情况。结果发现在模型组小鼠中小胶质细胞的数量较对照组增多,荧光强度增大且出现小胶质细胞胞体变大,揭示了小胶质细胞被激活。     

植物SOD的基因表达、活性调节及抗逆作用研究进展

超氧化物歧化酶(superoxide dismutase,SOD)是植物细胞清除氧自由基伤害的第一道防线,对于保护细胞免受氧化损伤有十分重要的作用。本文概述了植物SOD的基本性质、基因表达、活性调节以及与植物抗逆性的关系。     

活性氧代谢与植物的抗逆性

简述了植物体内活性氧的产生及其主要部位,活性氧对膜脂过氧化的启动以及活性氧对细胞膜系统结构的损伤,着重讨论了活性氧的清除与植物的抗逆性之间的关系,认为在各种逆境胁迫下,植物体内酶促与非酶促系统对活性氧的清除从而增强了植物的抗逆性,同时,应用一些外源新型植物生长调节剂可有效促进酶促系统清除活性氧,更好地增强植物对逆境的忍耐力。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.