65 resultados para Benthocosm D2


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近年来,世界沿海国家有害赤潮发生的频率、规模及危害都有上升趋势,有害赤潮已经成为重要的近海环境问题之一。要有效防范有害赤潮带来的危害效应,建立和发展可靠、有效的赤潮监测手段非常重要。目前,对于赤潮藻种的监测主要依靠显微观察的方法,在实际应用中经常遇到困难。首先,亲缘关系相近的物种在形态上差异很小,如甲藻门亚历山大藻属的一些种类,仅细胞壁上个别甲片的结构有细微差别,并且这些形态学指标还容易受环境条件及生长阶段的影响。另外,这种以形态学为基础的分析方法,分析速度慢、耗时长,对操作人员的要求较高,难以满足浮游植物种群动力学监测“量大、连续”的要求。因此,本研究将分子生物学的技术和方法应用于赤潮监测,力求提高赤潮藻种鉴定的准确性和检测工作的效率。 亚历山大藻是一类重要的有害赤潮藻,该藻属中一些产毒特性差别很大的藻种,单从表形特征难以明确区分,从而限制了基于形态观察的监测技术的应用。本研究中,我们尝试应用分子生物学技术与方法,开展了该藻属藻种分子鉴定和荧光原位杂交检测方法的研究。在亚历山大藻的分子鉴定方面,我们采用了核糖体RNA基因(rDNA)序列分析的方法,首次测定了9株分离自中国沿海的(以及实验室保有的其它两株)亚历山大藻的rDNA序列全长,其中包括核糖体小亚基(SSU)rDNA、大亚基(LSU)rDNA、5.8S rDNA及内转录间隔区(ITS)区序列。序列分析结果显示,这些藻株包含了5种核糖体类型,分别是塔玛复合种亚洲温带(Temperate Asian)核糖体类型(TSC-TA),塔玛复合种西欧(West European)核糖体类型(TSC-WE),相关亚历山大藻(A. affine)核糖体类型(AF),微小亚历山大藻(A. minutum)葡萄牙(Portugal)核糖体类型(M-PO)和微小亚历山大藻新西兰(New Zealand)核糖体类型(M-NZ)。将测获的rDNA序列划分为若干保守性不同的区段,分别进行系统发育分析(结合GenBank数据库中保存的其它亚历山大藻相关序列)。结果显示,LSU rDNA D1-D2区是对该藻属藻种进行分子鉴定和系统发育研究的较好区段。同时,为解决建立亚历山大藻克隆培养的困难,我们应用单细胞rDNA序列分析方法,对亚历山大藻单个细胞直接进行了种类鉴定。结果表明,该方法适用于不同生活史阶段的亚历山大藻。 在亚历山大藻的检测技术方面,我们进一步扩展和完善了针对完整细胞的荧光原位杂交检测方法。首先,通过对不同核糖体类型藻株rDNA序列信息的对比分析,针对各自特异的序列位点,设计了特异性rRNA标记探针。经荧光原位杂交实验检验,实现了对5种核糖体类型亚历山大藻的特异性标记。其中,针对WE、M-PO及M-NZ核糖体型的特异性探针为首次获得,另外两个探针是针对TA和AF核糖体类型rRNA新的位点所设计。同时,对影响探针标记效果的诸多因素进行了分析和探讨。此外,在2007年春季长江口海域赤潮调查中,首次应用特异性核酸探针和荧光原位杂交检测方法,调查了该海域亚历山大藻的丰度。结果表明,在4月4日-4月10日的样品中,亚历山大藻达到了较高的密度,最高密度达到103cells/L。同时发现,实验中样品的保存方法有待改进。随后的研究表明,盐醇固定方法及多聚甲醛/甲醇固定方法,可以较好的保持rRNA不被降解并适宜杂交(至少3个月时间)。 总之,本研究首次测定并分析了11株亚历山大藻(9株分离自中国沿海)的rDNA全序列信息。在此基础上,获得了5种核糖体类型亚历山大藻的特异性rRNA标记探针,其中3种为首次获得。另外,实验证明,单细胞rDNA分析技术和荧光原位杂交检测方法,在自然水体中亚历山大藻的直接鉴定及丰度调查中,均具有良好的应用前景。这一工作为我国近海亚历山大藻的鉴定和检测提供了理论依据和方法学基础,希望对该藻赤潮的监测工作有推动作用。 关键词:亚历山大藻 遗传探针 rRNA rDNA 荧光原位杂交 系统发育

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从抱茎獐牙菜的胚轴、幼叶及未成熟种子诱导出愈伤组织并再生植株,试验选用MS、B5 和N6 三种培养基,其中以附加2. 4 - D3. 0mg/ L + 6 - BA0. 5mg/ L的MS 培养基诱导率最高;以附加6 - BA0. 5mg/ L + NAA 0. 2mg/ L 的MS 培养基分化苗频率最高;以附加2. 4 - D2. 0mg/ L + 6 - BA0. 5mg/ L 的MS 培养基愈伤组织的生长最好。结果表明,外植体,培养基,激素等对愈伤组织诱导、继代和分化均有明显影响。采用高压液相色谱法(HPLC) 测定抱茎獐牙菜愈伤组织中齐墩果酸含量的结果表明,愈伤组织中齐果墩酸含量因培养基、继代培养时间的不同而有所差异。

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The Baoyintu Group, lies in Wulate-zhongqi, Inner Mongolia, is a set of medium-grade metamorphic rock series which undergoes complex deformations. It consists of pelite schist, greenschist, plagioclase amphibolite quartzite and marble. The pelite schist is the main rock type and contains the classic medium pressure metamorphic minerals. The author divided Baoyintu group into five assemblages, investigated the rock association and plotted geological section of each assemblage in this area. Based on the systemically study of structural geology, petrology, geochemistry and mineralogy, the author reconstructs the protolith, sedimentary environment and tectonic evolution, discusses the mesoscopic and microscopic structure, metamorphism, geochemistry characters and the correlation between porphyroblast growth and deformation-metamorphism. There are three phase deformations in the research area: the earliest one occurred as the Baoyintu group deformed and metamorphosed and the main structure pattern is tight fold within layers during the Dl, large scale reversed fold and two phase faults (Fl fault and F2 fault) during the D2, and superimposed fold and F3 fault during D3. The F3 trancate the Wenduermian group of Silurian. The second and third phase deformation are relate to the orogenic event of late period of early Paleozoic. According to the rock association ,characteristics of the rocks and research of geochemistry, we get some information of the sedimentary environment and tectonic evolution of Baoyintu group. The source rocks are a set of terrigenous deposits-volcanic formation which reflect the history of the tectonic setting: stable- active-restable. And there are two sedimentary cycle from first assemblage to fifth assemblage: from first assemblage to fourth assemblage is a course of progression and the fifth assemblage is a start of regression. We also get the information of the P-T-t path by studying petrographies and calculating temperature and pressure. The path is not similiat to any classic type. And the interpretation is different from the traditional opinion. The P-T-t path reflects the dynamic course of convergence and uplift, magma underplating, back-arc extension and convergence of continental margin. Applying the theory of deformation partitioning to this area, the author discuss the relationship between deformation and porphyroblast growth, and get the conclusion of the sequence of deformation and metamorphism. At the first time we measure the distribution of chemical composition within the porphyroblast by XRF, confirm the theory of deformation partitioning quantitative and get new understanding about growth phase of porphyroblast and growth mode of porphyroblast: porphyroblast grow in the manner as "rose flower", the growth is controlled by the deformation. The elements distribution in porphyroblast reflects the growth manner and indicate history of metamorphism and deformation. So, we can deduce the metmorphism and deformation from the elements distribution in porphyroblast.

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过去几十年,由于REE具有重要的物源和过程示踪的地球化学意义,又与核放射性元素(钢系元素)的地球化学结构类似,因此,稀土元素的表生地球化学分配和行为研究便成为微量元素地球化学研究的一个重要部分。目前"通过水体悬浮物吸附态REE组成变化分析研究水/微粒界面作用REE分异现象.的工作不少,但至今进行的胶体或其他微粒吸附REE的实验研究不多,且已有的实验未能对溶液介质条件(如pH、离子强度、阴离子、固/液比),尤其是天然有机物的控制机理进行系统研究,对所观察到的水体中REE及其他微量元素分布变化多样性的解释仍缺乏实验依据。本文用结晶良好且粘土矿物含量高的苏州高岭土、美国粘土协会高岭土(Kga-1b)和蒙脱土(Wwy-2)作为吸附剂,采用系列吸附实验定量研究了不同理化条件(如pH值、离子强度、固/液比)下,受溶液阴离子(Cl-、C1O4-、SO42-、HCO3-)和Fluka胡敏酸(HA)影响,REE在粘土/水界面的分配和分馏,并讨论了HA和粘土的相互作用及胡敏酸存在与不存在时的REE形态分布。得到以下几点重要认识,为合理解释地表水体中既E和其他微量元素分布变化的多样性提供了实验依据:1、REE在苏州高岭土/水界面的重现性实验结果为:稀土配分系数D的相对标准偏差最大值为Eu8.4%,其他大多介于5.0%和6.6%间。而稀土吸附率Rd的相对标准偏差最大值为D2.2%,其他大多<2%。较小误差表明本次研究所用实验方法是可行的。2、REE在苏州高岭土/水界面的动力学实验结果表明:短时间内(几分钟)稀土快速吸附在高岭土:接着因为粘土的层状结构,在20h内粘土层间金属与REE发生交换,稀土分配系数变化较大;20h以后能达到稳定的吸附/解吸平衡。因此本次研究采用的平衡时间为24h。3、pH分别为4.5和6.5时REE在苏州高岭土冰界面的分配能用Langmuir吸附等温线模拟和MINEQL+软件表达。与静电吸附相对应,pH值越高REE最大吸附量越大。同时REE浓度的差异造成了REE分馏,总的趋势是REE含量越高,分馏越不明显。4、近中性(pH=6.5)条件下不同阴离子的存在对REE在苏州高岭土/水界面分配和分馏的影响表明:随阴离子(Cl-、ClO4-、SO42-)含量升高REE吸附率降低,其中SO42-对REE吸附的影响最大,说明Na+质量效应和阴离子配合的影响;同时由于不同阴离子与轻重R陇的络合差异所致,阴离子含量越高,轻重稀土的分馏越明显(La/Yb=0.14-0.96),一般为阴离子含量的增加使得重稀土更多的被吸附,其中C1-和SO42+的影响最为明显。HCO3-虽然与REE有较强配合,但可能由于我们的HCO3-实验浓度低(<0.0O25mol/L),在我们的实验结果中其对REE吸附和分馏的影响较小。5、由于不同pH和介质条件下,REE的络合形态分布不同,它们可以影响其在水/粒界面的分配。应用MINEQL+模型,考虑REE的氢氧化物、碳酸盐和腐殖酸的影响,研究了REE的形态分布,结果表明fIA的存在对REE形态有很大影响:在HA不存在时,pH7-8间REECO3+为主要的REEs形态,在更低和更高pH值,REE主要存在形式分别为REE加和REE(CO3)2-;而当HA存在时,在1)H值3-9,REEHA成为主要形态,在低pH(<3)和高pH(>9)时REE3+和REE(CO3)2-分别为主要形态。6、在较宽的pH范围HA能吸附在粘土上意味着在大多数含HA的天然水体中,粘土表面被HA覆盖。随H增加粘土对HA的吸附降低,反应了配位体交换或表面络合反应引起的专属吸附,其他如疏水性、、腐殖物质的溶解和HA的结构变化可能也影响了吸附。HA含量、矿物表面积和离子强度等理化条件对HA吸附会产生影响,从而影响HA对粘土表面的覆盖和接下来的粘土对REE的吸附。7、溶液介质条件对REE在粘土(Kga-1b和SWy-2)/水界面分配和分馏的影响表明:主要与静电相互作用、离子交换反应相对应,除低PH外,REE在高岭土上的吸附表现出弱的pH依赖性;而随pH增加REE在蒙脱土上的吸附呈下降趋势,显示交换反应为吸附过程的主要因素。在两种粘土中REE吸附均为随离子强度增加而降低,反应了Na质量效应。8、腐殖物质在粘土表面的吸附改变了吸附剂的属性。HA存在时REE在固液界面的分配反应了REEHA在固液界面的分配和HA在高岭土或蒙脱土/水界面上的分配,其他如静电吸附等机制也影响了吸附:在高岭土中,HA会增加低pH(<4)吸附,随pH增加(>5)HA会降低吸附。与此不同,在整个PH范围(3-10),HA的存在明显降低了REE在蒙脱土上的吸附。REE吸附在高岭土上随队含量增加是先增加后降低。而蒙脱土实验中,在低HA含量(<5mg/L)处,RE阮吸附率与HA含量增加呈线性降低至几个百分比,而在高队含量处,REEs吸,附率无明显变化。这些清楚地说明水体环境中有机物的存在通常降低微量金属吸,附在微粒上,增加微量金属在水体中的溶解量,从而促进微量金属在水体环境中的长距离迁移。9、HA存在和不存在时,吸附/解吸过程中的REE分馏随pH或离子强度的变化都不明显,但由于REE系列与腐殖物质和矿物络合的差异,会随队含量的变化发生明显变化。通常溶液中高队含量增加了LREE在高岭土/蒙脱土上的吸附。这些结果是在HA存在时,微粒相上产生LREE富集的一个实验证实,也和大多数天然水体中的REEs分馏相一致。

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The conceptualization of “depression” as a heterogenous disease has been widely accepted by most researchers. However, controlled experiments are rather sparse. To date, most studies demonstrated that animals with helplessness, a widely recognized behavioral index of “depression” also show varied comobidity expressions of other emotional behaviors, such as hightened or lightened anxiety level compared with controls. This means that distinct subtypes of “depression” may exist, in which different neural mechanisms may play roles. The present study aims to explore the possibility of behaviorally categorizing two depressive subtypes, referred as anxious helplessness and non-anxious helplessness, respectively. Then, by using RT-PCR, the dopamine D1, D2, D3 receptors mRNA expressions in medial prefrontal cortex (mPFC) and nucleus accubems (NAc) were quantified. The main findings are described as belows: 1. Uncontrollable shock could readily induce helpless behavior in shocked animals as a whole but with salient individual differences. Prior inescaoable shock induces subsuquent helplessness in approximately 40% shocked animals, while the other animals showed no sign of helpless expression, and were classified as non-helplessness. 2. Among helpless animals, the “subtype” of anxious helpless and non-anxious helpless could be identified according to the anxiety level evaluated by elevated plus maze. 3. D3 receptors mRNA expressions in the mPFC and NAc were increased in stressed animals after uncontrollable shock treatment. At the meanwhile, significant lower expressions of D2 receptors in the mPFC and NAc, and much lower expressions of D1 receptors in the mPFC were found in rats that did not become helpless after stress. In contrast, no significant difference between helpless and control animals was found in D1/D2 receptors mRNA expressions. 4. Based on above mentioned results, the up-regulation of D3 receptors in the mPFC and NAc may reflect a generalized effect of exposure to uncontrollalbe shock. While the down-regulation of D1\D2 receptors in the mPFC and decreased expression of D2 receptors in the NAc may be associated with adaptive or protective mechnisms which protecting animals from helplessness after uncontrollable shock treatment. 5. Futhermore, a significant negative relationship was found between anxiety level and D1 receptors expressions in the mPFC in helpless animals. Compared to the non-anxious helpless and control rats, the D1 receptors mRNA of anxious helpless rats were down-regulation in the mPFC. The present study indicated that the D1 dopamine receptor gene is associated with co-morbid depression and anxiety.