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1.
镉在河南华溪蟹主要组织器官中的积累效应   总被引:2,自引:0,他引:2  
研究了急性染毒条件下,镉(Cd2 )在河南华溪蟹(Sinopotamon henanense)主要组织器官中的积累效应.实验设对照组、3个Cd2 浓度组(14.5 mg/L、29 mg/L和58 mg/L)和3个时间段(1 d、3 d和5 d).活体解剖,取肝胰脏、鳃、卵巢和肌肉进行消化并测定Cd2 含量.结果表明,Cd2 的积累具有明显的组织差异性,积累量由高到低的顺序是:鳃>肝胰腺>肌肉>卵巢.镉对蟹体的毒性作用具有一定的"浓度-效应"和"时间-效应"关系,即随着染毒镉浓度的升高,或处理时间的延长,Cd2 在组织器官中的积累也随之增加,呈现不同的变化趋势.  相似文献   

2.
重金属镉和铬对草鱼苗的急性和慢性毒性效应   总被引:4,自引:0,他引:4  
以草鱼(Ctenopharyngodon idellus)为受试生物,研究了重金属镉和铬(Ⅵ)对其鱼苗的急性毒性、慢性毒性以及组织学影响.急性实验结果表明:镉与铬(Ⅵ)对草鱼苗的联合毒性在24 h和48 h,AI>0,为协同作用.慢性实验结果表明:随着时间的延长,不同镉、铬(Ⅵ)质量浓度处理,肝胰脏中GPT活性呈下降趋势,两者联合处理质量浓度对GPT活性的影响呈现先升高而后又下降的趋势.组织切片观察结果显示:鳃、肝胰脏、肠和脾脏对重金属染毒表现出不同程度的病理变化.研究表明重金属镉和铬不仅能够影响草鱼苗主要酶的活性、使鱼体组织器官明显受损,而且两者表现出明显的协同损伤作用.  相似文献   

3.
探究了阴离子表面活性剂十二烷基苯磺酸异丙胺盐(DAMS)对异育银鲫(Carassius auratus gibelio)肝胰脏和鳃组织的氧化胁迫和组织学的影响.异育银鲫在水体不同浓度的DAMS中暴露28 d后,测定肝胰脏和鳃组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)活性以及观察肝胰脏和鳃组织的组织学切片.结果表明,DAMS对异育银鲫的96 h半致死浓度LC_(50)为19.83 mg·L~(-1);在亚急性暴露实验中,随着毒物浓度升高,异育银鲫肝胰脏和鳃组织的GSH-PX和SOD活性均表现出显著的抑制(P0.05),肝胰脏中MDA含量随暴露浓度的升高先上升后下降;高浓度暴露组鳃组织中MDA含量与对照组无显著差异,高浓度暴露组实验鱼的肝细胞出现明显的空泡化,鳃组织出现鳃上皮脱落等不同程度的损伤.结果暗示水体中的DAMS暴露对异育银鲫具有一定的氧化胁迫毒性.  相似文献   

4.
【目的】研究十二烷基苯磺酸异丙胺盐(DAMS)暴露对鲤(Cyprinus carpio)肝胰脏和鳃组织的氧化胁迫影响。【方法】设置1个水体DAMS质量浓度为0的对照组和5个水体DAMS质量浓度分别为0.5,1,2,4和8 mg·L-1的暴露处理组,暴露28 d。测定鲤肝胰脏和鳃组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC)水平。【结果】1) 与对照组相比,各暴露处理组鳃组织中MDA含量均有统计学意义上的增加(p<0.05),肝胰脏组织中MDA含量只在4和8 mg·L-1 DAMS暴露处理组有统计学意义上的增加(p<0.05);2) 与对照组相比,在0.5 mg·L-1 DAMS暴露处理组,鲤肝胰脏和鳃组织的T-AOC水平有统计学意义上的上升(p<0.05),但SOD活性无统计学意义上的变化;在1,2,4和8 mg·L-1 DAMS暴露处理组,鲤肝胰脏和鳃组织的SOD活性、T-AOC水平均表现出统计学意义上的下降(p<0.05)。【结论】水体DAMS暴露会破坏氧化及抗氧化系统的平衡,损害抗氧化系统,导致鲤的肝胰脏和鳃组织发生不同程度的氧化损伤。与肝胰脏组织相比,鳃组织中MDA含量、SOD活性和T-AOC水平对DAMS暴露更为敏感,因此鲤的氧化损伤程度和抗氧化能力存在较明显的组织特异性。  相似文献   

5.
镉对草鱼的急性毒性效应及SOD的影响   总被引:1,自引:0,他引:1  
以静水生物测试法研究了氯化镉对草鱼的急性毒性效应及其肝胰脏、肾脏和鳃组织的超氧化物歧化酶(SOD)的影响.结果表明:镉对草鱼的急性毒性作用时间为24,48,72和96 h的半数致死质量浓度(LC50)分别是45.58,34.81,28.63和24.05 mg.L-1,因此镉对草鱼的生态毒性为高毒.Cd2+低浓度时,肝胰脏和肾脏组织SOD活性均为"先降后升再降",而Cd2+为高浓度时SOD活性始终处于被显著抑制(p<0.05);鳃组织在低Cd2+污染时SOD活性为"先降后升",而高浓度的Cd2+污染时其SOD活性为"先降后升再降".但是草鱼鳃组织的SOD活性明显低于肝胰脏和肾脏的SOD活性.  相似文献   

6.
研究了舟山近海细点圆趾蟹中镉的分布特征。采集源自舟山海域的细点圆趾蟹雌雄个体各8个,按组织差异分别制备胸肌、腿肌、肝胰腺、性腺(雌性)、胃、心、鳃、肠,运用微波消解-电感耦合等离子体质谱法进行镉含量测定。结果表明,本方法采用2种国家生物成分分析标准物质实施质量控制,所测结果相对标准偏差均小于10.0%,符合实验精密度要求。细点圆趾蟹各组织的镉含量范围为0.007 46~7.56 mg/kg,各组织镉含量从高到低总体趋势为肠肝胰腺鳃≈胃≈性腺(雌性)心胸肌腿肌。数据表明,镉在雄性和雌性细点圆趾蟹中分布规律一致,肠和肝胰腺为主要富集器官,但雄蟹的镉平均含量水平偏高,分别是雌蟹的3.75和1.66倍。舟山近海细点圆趾蟹体内镉的主要富集部位集中在肠及肝胰腺组织。  相似文献   

7.
镉铅对泥鳅组织转氨酶活性的影响   总被引:3,自引:2,他引:3  
研究了镉(Cd^2+)、铅(Pb^2+)以及两者联合(Cd^2++Pb^2+)作用对泥鳅肝胰脏、肾脏及鳃谷丙转氨酶(GPT)和谷草转氨酶(GOT)活性的影响.结果表明,随着Cd^2+或Pb^2+暴露量的增加,肝胰脏、鳃GPT和GOT活性先升高后下降,而肾脏转氨酶活性则随Cd^2+质量浓度的升高而明显下降(P〈0.05或P〈0.01),随Pb^2+质量浓度的升高而极显著升高(P〈0.01).Cd^2++Pb^2+各质量浓度处理均引起组织GPT活性极显著下降(P〈0.01);而GOT被低质量浓度Cd^2++Pb^2+诱导,暴露量增加时又被明显抑制(P〈0.01).Cd^2+对泥鳅组织转氨酶活性毒性作用大于Pb^2+,Cd^2++Pb^2+联合抑制作用具有明显的协同效应.低质量浓度处理条件下,肝胰脏和鳃GOT及GPT活性受抑制明显;高质量浓度处理条件下,3种组织的转氨酶活性受抑制情况相似.  相似文献   

8.
铜、锌、镉对锯缘青蟹仔蟹代谢酶活力影响的实验研究   总被引:19,自引:2,他引:17  
测定锯缘青蟹仔蟹(背甲宽 31.0±3.5 mm;背甲长 23.0±2.8 mm)暴露在次致死浓度的铜、锌、镉离子溶液下 24 h后肝胰腺、鳃、肌肉碱性磷酸酶(AKP)、谷雨转氨酶(GPT)、谷草转氨酶(GOT)的酶活性.结果表明:低浓度重金属使仔蟹酶活力提高,高浓度时又对酶活力有明显的抑制作用.三种金属中,铜、镉对酶活力影响作用较锌显著.三种受试组织中,肝胰腺酶活力最易受重金属影响.  相似文献   

9.
为探讨重金属镉慢性暴露对斑马鱼卵巢的毒性效应及子代响应,将斑马鱼暴露于0,0.062,0.124,0.248,0.620,1.240 mg/L 6个镉体积质量.暴露21 d后,以脂质过氧化产物丙二醛(MDA)含量、卵巢组织超氧化物歧化酶(SOD)水平、过氧化氢酶(CAT)水平为终点评价慢性镉暴露对斑马鱼卵巢的毒性效应;以子代受精率、孵化率和96 h幼鱼体长为终点评价慢性镉暴露下斑马鱼的子代响应.结果表明:MDA含量随镉浓度的增加而显著升高,抗氧化防御体系被抑制.当ρ(Cd)≥0.248 mg/L时,子代的受精率和孵化率显著降低;当ρ(Cd)≥1.240 mg/L时,斑马鱼不育;当ρ(Cd)≥0.620 mg/L时,子代斑马鱼孵化失败.孵化成功后的幼鱼96 h体长随镉浓度的增加而显著降低.  相似文献   

10.
水体Cu2+对无齿相手蟹体内Cu2+分布和消化酶活性的影响   总被引:1,自引:0,他引:1  
采用生态学单因子梯度试验方法研究水体中不同浓度Cu2 对无齿相手蟹体内Cu2 分布以及主要消化酶活性的影响.随着水体中Cu2 浓度的升高,蟹外壳、鳃和肝胰腺中Cu2 的含量均随之增加.其中肝胰腺增加最多,鳃次之,外壳最少.当水体中Cu2 浓度为7.50 mg/L时肝胰腺中Cu2 的含量达到了0.286 4 mg/g,为对照组的8.2倍,是同一Cu2 浓度处理组外壳和鳃的4.3倍和2.3倍.不同浓度的Cu2 对无齿相手蟹的胃蛋白酶、淀粉酶、纤维素酶和类胰蛋白酶4种消化酶酶活表现出不同程度的抑制作用.Cu2 浓度越高,对酶的抑制作用越明显.其中,类胰蛋白酶最为敏感,平均抑制率达到了45.86%.水体中Cu2 浓度仅为0.01 mg/L时,抑制率就已高达32.86%,受抑制的程度也最明显.试验结果表明,随着水体中Cu2 浓度的升高,肝胰腺是无齿相手蟹Cu2 蓄积的重要靶器官,其消化酶活性的变化能灵敏地反映出Cu2 对无齿相手蟹毒性作用的程度.  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.
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   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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