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1.
近年来,颤抖病给中华绒螯蟹养殖业造成了巨大的经济损失.酚氧化酶原系统是甲壳动物最主要的体液免疫系统,当外源微生物侵入体内时,它发挥最基本的免疫防御作用来抵抗感染.酚氧化酶原系统的变化是蟹类健康状况的重要指标.prophenoloxidase和peroxinectin是酚氧化酶原系统中两个重要的体液免疫分子.实验从分子和蛋白两个水平研究了中华绒螯蟹酚氧化酶原系统与颤抖病的关系,建立了一种新的通过测定酚氧化酶原系统活性来判断蟹体质状况的方法.在分子水平上,中华绒螯蟹体液免疫分子prophenoloxidase和peroxinectin的部分基因序列被克隆和测序,并检测出这两种分子mRNA水平的表达情况与颤抖病的感染程度呈正相关,患病组蟹mRNA的表达水平远高于正常组;在蛋白水平上,酚氧化酶的活性被测定,在正常情况下,蟹体内酚氧化酶活性处于低水平状态,当被感染颤抖病后,酚氧化酶活性有一定程度的升高.这些结果提示了酚氧化酶原系统在抗颤抖病感染时起重要作用,为进一步研究预防和治疗颤抖病的新途径提供了理论依据.  相似文献   

2.
菜青虫是危害农作物的主要害虫,酚氧化酶在昆虫的生长发育过程中起着重要的调节作用,高效的酚氧化酶抑制剂对于发展新型"环境友好"杀虫剂有着重要的意义.设计合成了4种缩氨基硫脲类化合物,采用红外光谱、质谱和核磁共振谱对其进行结构鉴定,进一步研究了它们对菜青虫酚氧化酶的抑制作用,结果表明,4种化合物均有显著的抑制作用,其半抑制率IC50分别为2.88, 0.93, 3.60和0.22 μmol/L,有可能进一步开发成为以酚氧化酶为靶点的新型生物农药.同时,为基于缩氨基硫脲母核的酚氧化酶抑制剂的设计提供了数据基础.  相似文献   

3.
甲壳动物酚氧化酶分子结构与生物化学性质的研究进展   总被引:1,自引:0,他引:1  
酚氧化酶是一种含铜金属酶,是酚氧化酶原激活系统级联反应链中的关键酶,通过催化黑化反应在无脊椎动物非特异性免疫中具有重要作用。本文综述了甲壳动物酚氧化酶的分子结构及其生物化学性质。  相似文献   

4.
乳链球菌SB900肽聚糖对中国对虾免疫功能的影响   总被引:8,自引:0,他引:8  
利用注射法研究了乳链球菌SB900肽聚糖对中国对虾内环境的影响.研究结果表明LABPG经肌肉注射后可激活中国对虾体内的细胞防御体系,对对虾血淋巴中的抗菌、溶菌、酚氧化酶和超氧化物歧化酶几种免疫相关因子具有不同程度的诱导作用.体外实验表明LABPG对酚氧化酶原具有一定的激活作用.表明利用PG提高对虾免疫系统的功能是一条可行的途径.  相似文献   

5.
乳链球菌SB900肽聚糖对中国对虾免疫功能的影响   总被引:18,自引:0,他引:18  
利用注射法研究了乳链球菌SB900肽聚糖对中国对讷环境的影响。研究结果表明LABPG经肌肉注射后可激活中国对虾体内的细胞防御体系,对对虾血淋巴中的抗菌、溶菌、酚氧化酶和 氧化物歧化酶几种免疫相关因子具有不同程度的诱导作用。体外实验表明LABPG对酚氧化酶原具有一定的激活作用。表明利用PG提高对虾免疫系统的功能是一条可行的途径。  相似文献   

6.
为比较不同赤眼蜂酚氧化酶(PO)活性的大小,明确赤眼蜂种间免疫防御能力强弱,本研究通过研磨、离心提取松毛虫赤眼蜂Trichogramma dendrolimi、螟黄赤眼蜂T.chilonis、玉米螟赤眼蜂T.ostriniae匀浆液,首次测定了几种化学因子(Ca2+、昆布多糖、纤维素、右旋糖酐、脂多糖和丝氨酸蛋白酶抑制剂)对3种供试赤眼蜂匀浆液中酚氧化酶原激活系统(proPO-AS)的激活程度。结果表明:玉米螟赤眼蜂匀浆液PO活性最高,螟黄赤眼蜂次之,松毛虫赤眼蜂最低。Ca2+是激活供试赤眼蜂proPO的必需因子,且在0.03mol/L浓度下激活作用最强;昆布多糖和脂多糖也能有效激活proPO,0.01及0.05mg/mL昆布多糖能强烈激活PO活性;纤维素和右旋糖酐对PO活性存在显著抑制作用。结果证明了赤眼蜂种间存在明显的免疫能力差异。本研究建立了小型昆虫proPO-AS研究体系,为研究Wolbachia-小型昆虫的免疫互作体系奠定了基础。  相似文献   

7.
中华管鞭虾多酚氧化酶生化特性研究   总被引:1,自引:0,他引:1  
对中华管鞭虾中多酚氧化酶(PPO)的活性及其影响因素进行研究,讨论了最适反应温度、pH、特异性底物及其酶动力学性质,激活剂对酚氧化酶的激活作用,抑制剂对酚氧化酶的抑制作用。结果表明:中华管鞭虾酚氧化酶的最适反应温度为45℃,最适反应pH为8.0;十二烷基硫酸钠(SDS)对PPO的激活作用最大,其次为胰凝乳酶和β-葡聚糖,激活率分别为71.9%、62.4%和33.4%;4-己基间苯二酚对PPO抑制作用最强。  相似文献   

8.
一、引言取代的1—苯基—3—苯甲酰基脲和取代的1—苯基—3—苯甲酰基—2—硫脲是一类新型的杀虫剂,它不象有机磷或有机氯杀虫剂那样抑制胆碱酯酶或使昆虫的神经及内脏中毒,而是对质壳酶、酚氧化酶有影响,并能终止N—乙酰葡萄糖胺部分迁入到壳质链中去,从而破坏昆虫甲壳素的合成,终止昆虫的发育而致死。这种奇特的作用方式,引起了人们的重视。近年来这类新型杀虫剂的研制工作仍在广泛深入地进行。  相似文献   

9.
脂类是昆虫表皮重要成分之一,在避免昆虫体内水分蒸发、防止外源物质渗入和信息素合成等方面具有重要作用.脂肪酸去饱和酶(desaturases,desat)是脂合成通路的关键酶之一.文章以重要农业害虫-飞蝗为研究对象,对脂肪酸去饱和酶家族基因desats的表达及功能进行了研究.对飞蝗转录组数据库进行搜索结合基因组数据,获得...  相似文献   

10.
凤眼莲体内多酚氧化酶的生理化特性   总被引:1,自引:0,他引:1  
用无菌凤眼莲作材料,对其体内多酚氧化酶的生理化特性进行了较系统的研究,结果表明,凤眼莲体内的多酚氧化酶仅能氧化邻位二元酚;在酶的提取过程中,加入凤眼莲湿重1/10的PVP(聚乙烯吡咯烷酮)能保持多酚氧化酶的最大活性,酶氧化邻苯二酚的最适pH为6.8,对热不稳定,抗坏血酸和EDTA.2Na能明显地抑制酶的活性;多酚氧化酶主要存在于凤眼莲的线粒体内。  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.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<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   

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