三角褐指藻滤液提取物对东海原甲藻和盐藻生理特性的影响     

薛峤娜  王蕊  谭丽菊  王江涛 《海洋学报》2018,40(4):119-126

在实验室培养条件下，利用流式细胞仪从细胞生长、细胞大小、细胞膜完整性、酯酶活性等方面分别研究了三角褐指藻（Phaeodactylum triconutum）滤液提取物对东海原甲藻（Prorocentrum donghaiense）和盐藻（Dunaliella salina）为期6 d生物培养过程中生理特性的影响。结果表明，三角褐指藻滤液乙酸乙酯提取物对东海原甲藻表现出强烈的生长抑制作用，荧光检测显示，其能刺激细胞体积的增大，导致部分藻体细胞膜受损，酯酶活性在短时间内增强，随后受到显著抑制。而提取物对盐藻的生长抑制并不明显，盐藻细胞体积没有受到影响，细胞膜保持了高度完整，酯酶活性在第6天时才受到抑制作用。以上分析表明，东海原甲藻对三角褐指藻滤液乙酸乙酯提取物更加敏感，特殊的细胞内部结构特征有利于化感物质进入东海原甲藻的体内，直接导致藻细胞的死亡。化感物质引起的不同的生理响应中，酯酶活性指标具有更好的敏感性，是在环境压力下生物自我保护的一种应急方式。  相似文献   

副溶血弧菌（Vibrioparahaemolyticus）tdh2基因和鳗弧菌（Kanguillarum）ompU基因二联DNA疫苗制备及其对大菱鲆（Scophthalmusmaximus）免疫保护作用     

刘瑞  赵明君  杨慧  陈吉祥 《海洋与湖沼》2011,42(4):580-586

采用基因工程的方法,将副溶血弧菌的热稳定直接溶血素基因tdh2和鳗弧菌外膜蛋白基因ompU进行融合,在大肠杆菌中得到表达,并利用该融合基因构建二联DNA疫苗pEGFP．N1／tdh2-ompU。用DNA疫苗按10和50μg／尾的剂量通过肌肉注射免疫大菱鲆,对大菱鲆抵抗致病性副溶血弧菌和鳗弧菌的免疫效果进行研究。结果表明...  相似文献   

对虾白斑综合症病毒膜蛋白VP41A的功能研究     

周娟  熊生良  杨丰 《台湾海峡》2011,30(4):512-516

对虾白斑综合症病毒（WSSV）是对虾养殖的主要病害之一,在虾养殖业中造成了严重的损失．本研究从WSSV基因组中克隆到vp41a基因,大小约为900bp,发现该基因编码蛋白VP41A．通过构建重组质粒pET．His一卅J0表达了重组蛋白VP41A,大小约为43kDa．并通过Ni一琼脂糖珠交联下拉实验,在虾血细胞中找到一个能与VP41A相互作用蛋白,质谱分析发现该蛋白为细胞粘连蛋白,说明在WSSV感染宿主细胞的过程中蛋白VP41A可能发挥重要作用．本研究结果推动了WSSV与宿主对虾相互作用的研究,有利于探索病毒复制或转录的关键蛋白,为最终的病毒防治及快诛诊断提供科学依据．  相似文献   

Maintaining the stability of deviated and horizontal wells: Effects of mechanical,chemical and thermal phenomena on well designs     

《Geomechanics and Geoengineering》2013,8(3):167-178

Wellbore instability, particularly in shale formations, is regarded as a major challenge in drilling operations. Many factors, such as rock properties, in-situ stresses, chemical interactions between shale and drilling fluids, and thermal effects, should be considered in well trajectory designs and drilling fluid formulations in order to mitigate wellbore instability-related problems. A comprehensive study of wellbore stability in shale formations that takes into account the three-dimensional earth stresses around the wellbore as well as chemical and thermal effects is presented in this work. The effects of borehole configuration (e.g. inclination and azimuth), rock properties (e.g. strength, Young's modulus, membrane efficiency and permeability), temperature and drilling fluid properties (e.g. mud density and chemical concentrations) on wellbore stability in shale formations have been investigated. Results from this study indicate that for low-permeability shales, chemical interactions between the shale and water-based fluids play an important role. Not only is the activity of the water important but the diffusion of ions is also a significant factor for saline fluids. The cooling of drilling fluids is found to be beneficial in preventing compressive failure. However, decreasing the mud temperature can be detrimental since it reduces the fracturing pressure of the formation, which can result in lost-circulation problems. The magnitude of thermal effects depends on shale properties, earth stresses and wellbore orientation and deviation. Conditions are identified when chemical and thermal effects play a significant role in determining the mud-weight window when designing drilling programmes for horizontal and deviated wells. The results presented in this paper will help in reducing the risks associated with wellbore instability and thereby lowering the overall non-productive times and drilling costs.  相似文献   

Modelling of membranes in the material point method with applications          下载免费PDF全文

Fursan Hamad  Dieter Stolle  Pieter Vermeer 《国际地质力学数值与分析法杂志》2015,39(8):833-853

The objective of this paper is to formulate and validate an accurate MPM approach for the numerical simulation of the large displacement of membranes containing soil. In the proposed approach, the membrane is discretised by a surface mesh that allows accurate simulation of membrane stresses. The membrane is free to move through a three‐dimensional grid for a continuum consisting of tetrahedral elements. The approach is applied to model a geocontainer being released from a split barge, taking into account the frictional contact between the geotextile and the barge. No‐slip contact is assumed between the geotextile and the soil inside. The effect of geocontainer interaction is investigated by dropping a second container. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

PCR-DGGE解析阴离子交换膜生物反应器反硝化过程中微生物群落结构变化   总被引：3，自引：0，他引：3  

高孟春  梁方圆  杨丽娟  杨瑒  李冰  朱玉姣  顾雯  徐婕 《中国海洋大学学报(自然科学版)》2010,40(4)

通过扫描电镜和聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)方法考察了进水NO3-浓度变化对阴离子交换膜生物反应器微生物种群结构的影响。研究结果表明,在进水NO3-浓度从47.01 mg/L逐渐增加到168.55 mg/L的过程中,出水中NO3--N浓度满足我国饮用水水质标准中小于10 mg/L的要求。电镜扫描图显示微生物的形态结构发生了很大变化。对不同阶段的样品进行PCR-DGGE图谱和相似系数分析,发现随着反应的持续进行,微生物种群结构发生了演替变化,证实污泥微生物生态能够迅速进行优胜劣汰的筛选,调整内部微生物种群结构,从而达到适应环境的目的。  相似文献   

海洋沉积物中现存微生物化学标志物完整极性膜脂研究进展   总被引：3，自引：0，他引：3  

姚鹏  于志刚 《地球科学进展》2010,25(5):474-483

完整极性膜脂作为活的微生物细胞的化学标志物,能够反映海洋沉积物中现存微生物群落结构和生物量等信息.与生物学方法相比,完整极性膜脂分析技术具有无需培养、快速和普适性等特点.综述了海洋沉积物中细菌和古菌的细胞膜完整极性膜脂的组成特点及其在生物地球化学和微生物生态学等研究中的应用,重点评述了在生物地球化学循环中有特殊作用的微生物,如厌氧氨氧化细菌、甲烷氧化古菌、氨氧化古菌、具有四醚膜脂结构的海洋泉古菌等,或者是一些特殊生态系统,如冷泉、海底深部生物圈等研究中完整极性膜脂应用的进展.还简要介绍了完整极性膜脂的分析方法,并对其应用前景进行了展望.  相似文献   

壳聚糖超滤复合膜研制   总被引：1，自引：0，他引：1  

孙秀珍  张碧珍 《海洋学研究》1999,17(2):21-25

以聚醚砜（ＰＥＳ）、聚偏氟乙烯（ＰＶＤＦ）超滤膜、聚己内酰胺（尼龙－６）微孔滤膜为多孔支撑膜,将天然聚合物壳聚糖通过流涎法制成超滤复合膜。该复合膜性能优良,在操作压力为０．２５ＭＰａ的条件下,它对聚乙二醇（ＰＥＧ）的截留率及其渗透速度,分别为８７．２％～９８．４％和２．１～５９．０Ｌ／（ｍ２ｈ）。壳聚糖超滤复合膜性能的优劣与支撑膜的材质、孔径、壳聚糖的浓度、添加剂的分子量及成膜时的条件有关。  相似文献   

条斑紫菜类囊体膜蛋白质组双向电泳研究方法     

周伟  何林文  陆勤勤  朱建一  高山  杨睿灵  杨芳  王广策 《海洋科学》2013,(7)

本文以蓝绿温和胶电泳为工具,首次在国内用于条斑紫菜类囊体膜色素蛋白质复合物的研究。结果显示：（1）利用非离子型去污剂十二烷基麦芽糖苷（DM）增溶条斑紫菜类囊体膜,DM/Chla（w/w）15：1产生的效果较好,在BN-PAGE胶中可以分离到较多较清晰的条带。（2）选取蔗糖密度层50%条带制备得到的类囊体膜样品进行第一向BN-PAGE和第二向SDS-Urea-PAGE电泳实验。第一向电泳分离出4个蛋白复合物,对第二向电泳胶上的15个蛋白点切取做质谱鉴定,检测到PSⅡ 47KDa,PSⅡ 44KDa,cytochrome f ,PSⅡ D2,PSⅡ D1等蛋白。本实验证实了温和胶电泳与SDS电泳结合对于条斑紫菜这种原始红藻的类囊体膜研究方面应用的可行性。  相似文献   

5. Prebiotic Chemistry – Biochemistry – Emergence of Life (4.4–2 Ga)     

Robert Pascal  Laurent Boiteau  Patrick Forterre  Muriel Gargaud  Antonio Lazcano  Purificación Lopez-Garcia  Marie-Christine Maurel  David Moreira  Juli Pereto  Daniel Prieur  Jacques Reisse 《Earth, Moon, and Planets》2006,98(1-4):153-203

This chapter is devoted to a discussion about the difficulties and even the impossibility to date the events that occurred during the transition from non-living matter to the first living cells. Nevertheless, the attempts to devise plausible scenarios accounting for the emergence of the main molecular devices and processes found in biology are presented including the role of nucleotides at early stages (RNA world). On the other hand, hypotheses on the development of early metabolisms, compartments and genetic encoding are also discussed in relation with their role in extant living organisms. The nature of the Last Common Ancestor is also presented as well as hypotheses on the evolution of viruses. The following sections constitute a collection of independent articles providing a general overview of these aspects.  相似文献