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1.
泥蚶血红蛋白的制备及其抗菌活性研究 总被引：3，自引：2，他引：1
利用凝胶层析技术从泥蚶血细胞裂解物中分离纯化得到两种血红蛋白,回收率为74.3%,并通过Tricine-SDS-PAGE和质谱技术鉴定为Tg-HbⅠ(同源二聚体)和Tg-HbⅡ(异源四聚体)。分别通过琼脂扩散法和分光光度法测其抗菌活性和过氧化物酶活性,结果发现,两种Tg-Hb对大肠杆菌和恶臭假单胞杆菌均有抗菌活性,Tg-HbⅡ对于恶臭假单胞菌和大肠杆菌的MIC值分别为0.063mg/mL和0.13mg/mL,Tg-HbⅠ对两种菌的MIC均为0.048mg/mL;两种Tg-Hb均具有过氧化物酶活性,能催化愈创木酚、邻苯二酚、对苯二酚、苯酚、左旋多巴等多种酚类物质。在Tg-Hb中添加GSH后,两种Tg-Hb均不再对恶臭假单胞杆菌具有抗菌活性。可见,两种Tg-Hb对恶臭假单胞杆菌等的抗菌活性均是通过其过氧化物酶活性发挥作用的。 相似文献
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采用随机克隆、功能筛选、逐次排除和同源比较的基因克隆新策略进行克隆假单胞菌(Pseudomonas sp．cn4902)磷酸甘油磷酸酯酶基因的研究。结果表明，该结构基因长819bp，与铜绿假单胞菌的磷酸甘油磷酸酯酶基因的核苷酸一致性达61．5％，氨基酸同源性为56．2％。该基因已输入GenBank数据库，收录号AF348165。将该基因转化大肠杆菌，受体菌在含NaCl 1．0mol／L的培养基中甘油含量升高2．9倍，最终菌浓度提高3．6倍。可见这是一个与生物耐盐性相关的主基因，以其转化、培育耐盐农作物的前景十分光明。 相似文献
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三唑磷对泥蚶急性毒性及血清SOD, CAT酶活性的影响 总被引：9，自引：0，他引：9
三唑磷对泥蚶(Tegillarca granosa)的48h LC50为21．0mg／L，96h LC50为10．2mg／L，依此设计三唑磷对泥蚶的胁迫质量浓度(1．1，2．2，4．4，22mg／L)，分别于胁迫后第0．5，1，2，4，8天及解除胁迫后第4天采样，研究三唑磷胁迫后泥蚶血清超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的变化情况。结果表明，随三唑磷胁迫浓度和时间的不同，泥蚶血清蛋白质质量浓度无显著性差异；在0.5，1d时各处理组的SOD无显著影响，从第2天起，SOD活性显著下降，48h的LC50为3．62mg／L；CAT的活性在第1天显著升高，而后逐渐降低。三唑磷胁迫下，SOD，CAT活性呈现一定的剂量效应与时间效应。胁迫解除后，蛋白质、SOD和CAT均得到不同程度的恢复，表明泥蚶具有一定的生理调节机能。 相似文献
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对东风盐场9个站位卤水中由藻类植物产生的可溶性糖浓度的变化规律及其与海盐产量和质量之间的关系进行了研究。结果表明，各站位可溶性糖含量的变化范围为0．7－124．3mg／L，以6月份最高，2月份最低；卤水中可溶性糖在111mg／L－215mg／L范围内，结晶盐的产量随卤水中可溶性糖含量的增加而提高，但同时降低了NaCl的含量，并增加了可溶性杂质及水分的含量，从而降低了盐质。初始可溶性糖浓度为111mg／L、137mg／L、160mg／L、193mg／L和215mg／L的25．4°Be’的卤水，在日照下实验12天，其对应结晶盐的NaCl含量分别为91．66％、90．63％、90．48％、90．23％和88．46％，可溶性杂质的含量分别为3．05％、3．32％、3．33％和4．54％。 相似文献
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经离子交换和分子筛层析从紫球藻（Porphyridium cruentum）和海水小球藻（Chlorella sp．）中分离纯化得到2种凝集素，研究它们对几种不同类型细胞即动物和人血红细胞、海洋和淡水微藻、细菌和真菌的凝集活性。研究结果表明，2种微藻凝集素对它们当中一些类型的细胞或种类具有不同程度的凝集活性，其中对水生聚胞藻（Synechocystis aquetilis）的凝集活性最强，最低质量浓度只需0．0313g／L。 相似文献
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臭氧氧化分解污泥的试验研究 总被引：4，自引：0，他引：4
臭氧氧化能有效地分解污泥，为对臭氧氧化后污泥性质的变化进行系统的研究，本文采用接触反应柱对污泥在臭氧氧化过程中性质的变化进行了研究。结果表明，在臭氧投量为0．1gO3／gSS时，污泥中的溶解性COD浓度从256mg／L增加到2126mg／L，污泥沉降速度由初始的0．19cm／min增至1．43cm／min，滤饼的含水率由初始的76．6％降至70．6％。臭氧氧化后污泥絮体被分解，产生大量悬浮粒子，使污泥上清液的浊度和悬浮物浓度增加。臭氧氧化处理后污泥的过滤性能恶化。污泥比阻增大。 相似文献
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初步研究了一定粒径的转炉钢渣对日本对虾（Penaeus japonicus）幼虾和中国明对虾（fenneropenaeus chinensis）幼虾的急性毒性效应。实验结果显示，当钢渣质量浓度为1.8g／L时，日本对虾幼虾96h的最高死亡率为33．33％；随着钢渣质量浓度的增加，死亡率增高；当钢渣质量浓度为18g／L时，其96h的最大死亡率达到了75％。相对于日本对虾幼虾，钢渣质量浓度为18g／L时中国明对虾幼虾96h的最高死亡率只有36．67％。运用直线内插法求出钢渣对日本对虾幼虾96h半致死浓度为1．62g／L，钢渣对日本对虾的安全浓度为0．162g／L，而在实验条件下中国明对虾幼虾的半致死浓度要明显高于日本对虾幼虾。 相似文献
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海洋褐藻羊栖菜(Sargassum fusiforme)中马尾藻甾醇、岩藻甾醇的分类纯化及抗菌、抗氧化活性研究 总被引：1，自引：0，他引：1
本文评价海洋褐藻羊栖菜(Sargassum fusiforme)中分离纯化的总甾醇、马尾藻甾醇(Saringosterol)和岩藻甾醇(Fucosterol)抗菌和抗氧化活性。马尾藻甾醇和岩藻甾醇化合物采用红外光谱、核磁共振光谱和高分辨质谱确定其结构。实验结果显示,总甾醇含量在30、60和80mg/m L对金黄色葡萄球菌(Staphylococcus aureus)和变形链球菌(S.mutans)具有抑制作用。马尾藻甾醇和岩藻甾醇对金黄色葡萄球菌和变形链球菌具有高活性,最小抑制浓度范围为4—32mg/m L。总甾醇还显示出对大肠杆菌(Escherichia coli)菌株1924和1356的抗菌作用。而马尾藻甾醇和岩藻甾醇在4—32mg/m L浓度范围内体外对大肠杆菌的抗菌作用不明显。马尾藻甾醇和岩藻甾醇对耐药性革兰氏阳性临床分离菌株具有显著的抑菌活性。另外,药理实验结果显示,总甾醇、马尾藻甾醇和岩藻甾醇的抗氧化活性与它们清除DPPH、ABTS、超氧化物和羟基自由基的能力有关。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
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Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献
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The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献