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1.
闽南养殖九孔鲍暴发性流行病的病原研究   总被引:4,自引:0,他引:4  
从1999年春季东山县九孔鲍暴发流行病的病鲍内脏提取病原粗提液,经电镜观察和回归感染实验,证实其病原主要是病毒合并细菌感染,细菌为两种弧菌,病毒为球形,其发生基质为细胞质中一种双层膜的泡状结构,观察到病原入侵后引起鲍的组织细胞产生严重的病理变化,探讨病原的入侵途径,提出预防该流行病的一些措施.  相似文献   

2.
九孢鲍暴发性流行病的病原及病理   总被引:18,自引:0,他引:18  
1999年2-5月,山东县养殖九孔鲍暴发了大规模流行病,不少养殖场全场覆没,病鲍表现为分泌粘液增多、肝脏红肿、中部僵硬和反应迟钝,应用磷钨酸负染、超薄切片的电镜和现场检测等方法,对病鲍的病原及肝肠组织的病理情况进行观测,结果表明引发这次养殖暴发严重病害的主要病原是致病力很强的病毒和弧菌,电观察到病毒发生在细胞质中的一种称为“封入体”的泡状结构,证实了病原的入侵造成九孢鲍肝及肠等组织、细胞产生病变,描述了细胞和病毒混合感染导致九孔鲍细胞的病理变化。  相似文献   

3.
通过注射灭活病毒,研究接种免疫对九孔鲍(Haliotis diversicolor supertexta)非特异性免疫机能和免疫保护效果的影响.试验结果表明:九孔鲍接种灭活病毒7d后,体液抗菌活力、溶菌活力和酚氧化酶活性都有显著提高(P〈0.01);35d后体液抗菌活力和酚氧化酶活性回落至本底水平,与对照组差异不明显(P〉0.05),溶菌活力则仍然高于对照组水平(P〈0.01).注射灭活病毒A的免疫效果好于灭活病毒B,九孔鲍接受灭活病毒后引起的免疫应答强度、产生的非特异性抗感染免疫能力和特异性抗感染免疫保护效果都是前者高于后者,且免疫35d后九孔鲍获得的抗特异性病毒感染免疫保护率,灭活病毒A为30%、灭活病毒B为20%.  相似文献   

4.
为探讨对虾暴发性流行病的致病机理,进行人工感染实验,并对感染中国对虾的胃组织进行了显微和亚显微结构特征的系统观察.观察结果表明胃是该暴发性流行病病毒首先感染的主要的靶器官之一,暴发性流行病病毒能侵入胃壁多种细胞并在其中复制,其中,胃上皮细胞是该病毒的主要的靶细胞.  相似文献   

5.
1993~1995年中国对虾发生暴发性流行病,经对患病对虾作组织病理学研究和电镜观察,发现此病以消化系统病变更为严重,肝胰腺,胃及肠道上皮层发生变性和坏死,上皮细胞破坏,细胞核肿大;结缔组织发生水肿,血淋巴细胞浸润,在电镜下,病变组织的细胞核内充满一种杆状病毒,大小为260~310nm×90~110nm外被双层囊膜,不形成包涵体,纯化的病毒经负染后在电镜下见到的大多数是病毒核衣壳,大小为286nm  相似文献   

6.
应用光镜和电镜研究斑节对虾白斑综合症杆状病毒( WSBV) 的形态和感染的组织病理,结果证实WSBV 感染的细胞解体坏死.电镜观察对虾肝胰腺细胞未发现病毒粒子,而鳃上皮细胞和甲壳表皮细胞感染3 种杆状病毒,分别称之为细胞质杆状病毒,细胞核Ⅰ型杆状病毒,细胞核Ⅱ型杆状病毒,病毒粒子大小分别为(102 ~112) nm ×(308 ~326)nm ,(98 ~105) nm ×(265 ~275) nm ,(101 ~112) nm ×(391 ~420) nm .病毒不形成包含体.负染后病毒粒子还可见细端有一乳头状结构,大小约40 ~50 nm ,后带有一宽约18 nm 、长约340 nm 的尾.  相似文献   

7.
对虾疫病病毒的快速检出,是防治暴发性流行病的关键所在。本文简述了利用电镜负染技术,电镜超薄切片技术和聚合酶链反应邓PCR技术等检测对虾疫病的具体方法,并且对结果进行了讨论。  相似文献   

8.
ThePreliminaryStudyonHHNBVinGrow-outPhaseWangJianping;ShenTuJikang(NingboFisheriesResearchInstitute,Ningbo315012)自1993年出现全国流行病对虾暴发性病毒病以来,我国的养虾业始终处于低谷。目前终于发现其病原是一种囊状无包涵体的DNA病毒,称之为对虾“皮下及造血组织坏死杆状病毒”(HNBV)。该病毒的治疗仍无法解决。但我们可以用核酸探针点杂交法来检测对虾HHNBv的发展程度,摸索对虾暴发性病毒病的暴发时间,减少其所带来的经济损失。本文也是我们今后对虾在分子生物学上开展研究的第一步。1材料与方法1.1样…  相似文献   

9.
对九孔鲍拮抗副溶血弧菌感染过程中血淋巴免疫球蛋白样物质、补体(C3、C4)样物质、C反应蛋白样物质的变化进行检测,结果表明,在拮抗副溶血弧菌感染的免疫应答中,九孔鲍血淋巴液中免疫球蛋白样物质IgG-like、IgA-like、IgM-like,补体样物质C3-like、C4-like,C反应蛋白样物质CRP-like等呈现急剧增加,尔后逐渐减少,有时甚至大量被消耗的变化特点,其变化与机体抗感染免疫应答过程及免疫原剂量存在一定的相关性.血淋巴中三类免疫球蛋白样物质和二类补体样物质含量峰值一般出现在注射感染后6-24 h,48 h后下降,有时甚至降低至本底水平,C反应蛋白样物质质量浓度在感染后12-96 h内都较高,168 h后接近本底水平.副溶血弧菌感染剂量对上述物质的表达速度和水平皆有正面影响.  相似文献   

10.
在非生物环境因子对暴发性流行病病原实验感染的中国对虾发病影响的基础上,用光镜和电镜观察对虾中肠组织,观察结果表明:中肠上皮细胞水样变性,少量的上皮细胞被感染,肠腔内致病菌继发性感染,中肠肌细胞发生凋亡,大颗粒细胞、小颗粒细胞形成大量的颗粒通过胞吐作用参入体液免疫。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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