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1.
中华鳖红底板病和白底板病病原及组织病理   总被引:1,自引:0,他引:1  
红底板中华鳖和白底板中华鳖中均发现细菌和病毒.经细菌培养证实红底板和白底板鳖肝、脾、肾、肺、心和鳃样组织中均有细菌,电镜观察也证实白底板鳖肝和肺中有细菌,红底板鳖肺和鳃样器官中有细菌.细菌短杯状,大小(0.5~0.6)μm×(0.8~1.0)μm.在白底板鳖脾、肾和胃中和红底板小场中分别检测到直径为70~75um和85~90um的病毒粒子.红底板病鳖和白底板病鳖均表现为广泛地系统性的组织坏死,白底板病鳖较红底板病鳖病变严重.  相似文献   

2.
日本对虾中肠腺坏死杆状病毒病的组织细胞病理研究   总被引:1,自引:0,他引:1  
对广东省湛江市一个养殖场养成期日本对虾和一个育苗场育苗期仔虾进行组织病理和电镜检测,在其肝胰腺上皮细胞核中发现中胸腺坏死杆状病毒,在宿生细胞核中不形成包涵体,呈游离状,成熟病毒粒子大小322um×73um,所致宿主细胞核肿大,染色质边移减少,细胞坏死解体.  相似文献   

3.
养殖斑节对虾红体病病原及组织病理研究   总被引:3,自引:0,他引:3  
养殖班节对虾红体病病原经组织病理、电镜观察和白斑杆状病毒PCR检测,初步证实是一种枝原体.枝原体高度多态性,主要以球状体和分枝丝状体形式存在.球状体直径60~108um,分枝丝状体膨大部直径达150um,丝状部为25um.枝原体主要寄生在斑节对虾肝胰腺上皮细胞、造血组织细胞、鳃上皮细胞、甲壳表皮细胞等,致肝胰腺萎缩糜烂.受感染细胞细胞质空泡变性,细胞核固缩解体,内质网、高尔基体和溶酶体消失.对红体带白斑斑节对虾、白斑(无红体特征)斑节对虾和红体(无白斑特征)斑节对虾组织病理、电镜和白斑杆状病毒PCR检测,证实斑节对虾红体病不是由白斑杆状病毒引起,红体斑节对虾具有白斑杆状病毒是病毒继发感染所致.  相似文献   

4.
嗜水气单胞菌的致病性研究   总被引:1,自引:0,他引:1  
自患红脖子病的中华鳖中分离的嗜水气单胞菌菌株对小白鼠有致死性,腹腔注射小白鼠的24h半致死剂量为6×105/g,对中华鳖腹腔注射在7d内的半致死量(LD50)为1.18×1010/g中华鳖(体重).腹腔注射感染、灌胃感染、水体感染和伤口感染还可导致中华鳖慢性感染,致死时间在20d以后.水体感染产生中华鳖红脖子病的全部症状.  相似文献   

5.
班节对虾白斑综合症杆状病毒(Whitespotsyndromebaculoviruses,WSSBV)感染胃上皮细胞,胃环肌和纵肌细胞,海绵结缔组织细胞;鳃下皮细胞;触角腺分泌型和非分泌型上皮细胞,触角腺体胶囊上皮细胞;造血组织细胞;心脏心肌细胞,随体细胞,结统组织细胞;神经系统胶质细胞,神经膜细胞,神经细胞和球形细胞;甲壳表皮细胞、肌细胞.WSSBV对中肠和中肠育囊上皮细胞,肝胰腺上皮细胞,雄性生殖系统精原细胞,输精管上皮细胞等不敏感.人工肌注感染,WSBV有3d内可致斑节对虾90%,甚至100%死亡.感染斑节对虾鳃经电镜观察发现了3种杆状病毒,2种为无包涵体细胞核杆状病毒,其中一种大小为(119~136)um×(289~306)um,核农壳(98~105)nm×(265~272)um,另一种大小为(101~112)um×(391~420)um,核衣壳(78~85)nm×(276~298)um;1种为细胞质杆状病毒,大小为(102~112)nm×(326~340)um,核衣壳(71~78)nm×(306~308)um.  相似文献   

6.
细胞骨架系统的活动   总被引:1,自引:0,他引:1  
在细胞质中含有复杂的胞质纤维网,根据纤维大小分为微管(20~25um),微丝(5~6um),中间纤维(7~11nm)和微梁网络(3~6um)。这些纤维组成了细胞质骨架系统。近几年来,又发现在细胞核内存在以蛋白质为主,含少量RNA的精细网架体系的细胞核骨架。细胞骨架并非静止的,而处于高度动态之中,相互连接并结合到核以及其它膜束缚的细胞器上,与细胞活动密切相关。一、细胞的变形运动和变纳膜运动原生动物变形虫在固体表面移动时,向前伸出一个或多个伪足,将体内部分原生质移入伪足内,后面的原生质也随着收缩前进,不断地补充向前流动…  相似文献   

7.
嗜水气单胞菌的分离及其生理特性   总被引:1,自引:0,他引:1  
自患红脖子病的中华鳖中分离一株细菌,经鉴定为嗜水气单胞菌.该菌株在Arg,Leu,Asp和Met4种氨基酸为碳源的合成培养基生长良好,最适生长条件为pH7.0,28℃以及液体培养基中溶解氧7.5~10g/L.在合成培养基础上,氨基酸Ser,Val,Trp,Ala和Phe有较强的促进嗜水气单胞菌生长的能力.锌离子抑制细菌的生长;低浓度的铁离子对细菌生长有一定的促进作用.镁离子则是嗜水气单胞菌生长必须的.胺基糖类抗菌素(青霉素类)对嗜水气单胞菌不抑制.  相似文献   

8.
在水仙花叶病叶片细胞中观察到长杆状(约470~550×12~13nm)的水仙花叶病毒及相应的病毒内含体.在病毒感染和增殖的过程中,水仙感病细胞的质膜、细胞核、叶绿体及液泡等结构发生一系列的反应和变化.观察结果不仅进一步证明病毒内含体是寄主植物抑制病毒活动的一种方式,而且揭示液泡吞噬病毒是植物细胞抵抗病毒危害的一种重要方式.  相似文献   

9.
感染新疆甜瓜的黄瓜花叶病毒的生物学特征   总被引:1,自引:0,他引:1  
从新疆感染病毒病的甜瓜(Cucumis melo)分离到一株球形病毒.该病毒在人工接种条件下可经汁液传播侵染属于9科的24种草本植物;该病毒可经桃蚜以非持久性方式传播;染病组织粗汁液和提纯病毒制备物在SDS双向免疫扩散试验和酶联免疫吸附试验(ELISA)中与黄瓜花叶病毒抗血清发生强烈的免疫反应;该病毒的病毒粒子为直径28~30nm的球形病毒粒子;以差速离心和蔗糖密度梯度离心提纯了该病毒,纯化病毒的A260/A280为1.65;用提纯病毒制备了ELISA试验效价为1:10^7的抗血清;该病毒可经西瓜、甜瓜和西葫芦种子以较低的种子带病率传播.实验证明该株病毒应属于黄瓜花叶病毒(Cucumber mosaic virus)的一个株系,建议将该株病毒称为黄瓜花叶病毒新疆株(Cucumber mosaic virus-Xinjiang,CMV-XJ).  相似文献   

10.
感染新疆甜瓜的南瓜花叶病毒的鉴定   总被引:1,自引:0,他引:1  
从感染病毒病的新疆甜瓜中分离到一株属于豇豆花叶病毒科的球形病毒,该株病毒在人工接种条件下可经汁液传播侵染属于3科的9种草本植物,但仅在葫芦科植物上才引起较为严重的系统侵染症状;该病毒可经叶甲以非持久性方式传播,但经桃蚜则不能传播,且染病组织粗汁液和提纯病毒制备物在SDS双向免疫扩散试验和酶联免疫吸附试验(ELISA)南瓜花叶病毒抗血清发生强烈的免疫反应;该病毒的病毒粒子为直径28~30nm的球形病毒粒子,以差速离心和蔗糖密度梯度离心提纯了该病毒,纯化病毒的A260/A280为1.60;用提纯病毒制备了ELISA试验效价为1:10^11的兔子抗血清;该病毒可经染病甜瓜和西葫芦果实的种子分别以2.0%和2.6%的种子带毒率传播.该株病毒被证明应属于南瓜花叶病毒的一个株系,建议将此株病毒称为南瓜花叶病毒新疆株(Squash mosaic virus-Xingjiang,SqMV-XJ)抗血清;该病毒可经染病甜瓜和西葫芦果实的种子分别以2.0%和2.6%的种子带毒率传播,证明该株病毒被应属于南瓜花叶病毒的一个株系,建议将此株病毒称为南瓜花叶病毒新疆株(Squash mosaic virus-Xinjiang,SqMV-XJ)。  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
《海外英语》2007,(4):36
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.  相似文献   

13.
王菲 《华章》2007,(12):273-273
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.  相似文献   

14.
裴水妹 《华章》2007,(11):196
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.  相似文献   

15.
16.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

17.
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.  相似文献   

18.
STORIES     
正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.  相似文献   

19.
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between  相似文献   

20.
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.  相似文献   

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