SYNTHESIS AND CRYSTAL-STRUCTURES OF A NEW NONCYCLIC LIGAND AND ITS LANTHANIUM(III) COMPLEX

A new non-cyclic ligand, tris(4-carboxy-3-oxabutyl) amine (H3L . HCl) and its lanthanum(III) complex have been prepared and their crystal structures determined. In the lanthanum(III) complex the metal ion is coordinated to one nitrogen atom, three ether o

ELECTROCHEMICAL AND ELECTROCATALYTIC PROPERTIES OF IRON(III)-SUBSTITUTED DAWSON-TYPE TUNGSTOPHOSPHATE ANION

The electrochemical and electrocatalytic properties of iron(III)-substituted Dawson-type tungstophosphate anion are described. The anion exhibits a one-electron couple associated with the Fe(III) center and two two-electron waves attributed to redox proce

M(NTEA)配合物的NMR研究(M=La，Y，Lu和Ca)

近年,水溶性非离子化的稀土配合物由于可用作潜在的NMR造影剂而受到重视,特别是热力学和动力学均稳定的Gd(Hp-DO3A)和Gd(DTPA-BMA)已应用于临床医学诊断。前文报导了新螯合剂—氨三乙氧基乙酸(NTEA)的合成及其La配台物单晶的结构分析。

ELECTROCHEMICAL AND IN-SITU SPECTROELECTROCHEMICAL STUDY OF (TETRAPHENYLPORPHINATO)MANGANESE(III) PERCHLORATE IN THE PRESENCE OF CHLORIDE ANIONS .2. OXIDATION PROCESSES

An investigation of electrode oxidation processes of (tetra-phenylporphinato) manganese (III) Perchlorate, (TPS)Mn(III)ClO4, was carried out during the titration of chloride anions by conventional cyclic voltammetry, thin-layer cyclic voltammetry and spectroelectrochemistry. It was demonstrated that in the presence of one equivalent amount of Cl-, the first one electron oxidation reaction corresponds to the Mn(III)I cation radical oxidation, and the second one electron oxidation corresponds to the cation radical/dication generation followed by an iso-porphyrin formation reaction, however in the presence of two equivalent amount of Cl-, the first one electron oxidation of Mn(III) gives Mn(IV) porphyrin and the second one electron oxidation generates cation radicals of Mn(IV) followed by an iso-porphyrin formation reactions. Mechanisms of these redox processes are postulated.

ELECTROCHEMICAL AND INSITU SPECTROELECTROCHEMICAL STUDY OF (TETRAPHENYLPORPHINATO)MANGANESE (III) PERCHLORATE IN THE PRESENCE OF CHLORIDE ANIONS .1. REDUCTION PROCESSES

The mechanism of electrochemical redox reactions of (tetra-phenylporphinato) managanese(III) perchlorate, (TPP)Mn(III)ClO4, was studied In the presence of chloride anions in dichloroethane solution. It was demonstrated that Mn(II) or Mn (III) centre can be coordinated with only one chloride anion, this result makes an about 100 mV negative shift of half-wave potential of Mn (III)/Mn (II) reduction. An equilibrium constant of 2.2 x 10(4) was determined for the complexation reaction of Cl- and Mn(III) centre.

ANALYSIS OF ANGULAR OVERLAP PARAMETERS FOR EU3+ - LN2O2S (LN = LU, Y, GD, LA) CRYSTAL SERIES

The angular overlap model (AOM) is applied to 4f6 electron systems. The crystal field parameters are interpreted and covalency between 4f electrons and ligands is investigated based on the experimental energy levels. For Eu3+:Ln2O2S (Ln = Lu, Y, Gd, La) crystal series, we adopt two computational schemes. First of all, we assume that the distances to all ligands are equal, and then the distances to all ligands are divided into two groups, namely, oxygens as one group, sulfurs as the other. Of course, much information about covalency will be obtained from the latter case. Obviously, our results show that the covalency of Ln-O bonding is stronger than that of Ln-S bonding in line with much shorter bondlength for the former than that for the latter. The two schemes yield the same results, that is, for sigma and pi bonding, ligands are strong donors as well as sigma, pi effects are dominant over delta, phi effects.

Eu~(3+):Ln_2O_2S(Ln=Lu,Y,Gd,La)晶体的角重迭晶场参数计算

本文使用角重迭模型(AOM)在考虑其全部四个参数e_σ、e_π、e_δ和e_φ的基础上,对Eu~(3+):Ln_2O_2S(Ln=Lu,Y,Gd,La)晶体的角量迭晶场参数进行了计算。结果表明,与σ、π反键有关的参数e_σ、e_x的数值相对较大,特别是e_σ值在这四个参数中为最大,而e_δ和e_α值则较小,在近似计算中可以忽略。这四种稀土硫氧化物的成键本领(或能力)按由大到小排列,其次序为Lu>Y>Gd>La。

Eu~(3+):Ln_2O_2S(Ln=Lu,Y,Gd,La)晶体的角重迭参数计算

本文使用角重迭模型(AOM),针对Eu~(3+):Ln_2O_2S(Ln=Lu,Y,Gd,La)晶体系列,在考虑硫和氧两种不同格位的情况下,对f电子的全部四个角重迭参数e_σ、e_π、e_δ和e_φ进行了计算,得到了一些基本规律,即中心离子与配位体之间的共价性大小次序为Lu～Y>Gd>La,并且Ln-O键的共价性要强于Ln-S键.

Investigation of EscA as a chaperone for the Edwardsiella tarda type III secretion system putative translocon component EseC

Edwardsiella tarda is an important Gram-negative enteric pathogen affecting both animals and humans. It possesses a type III secretion system (T3SS) essential for pathogenesis. EseB, EseC and EseD have been shown to form a translocon complex after secretion, while EscC functions as a T3SS chaperone for EseB and EseD. In this paper we identify EscA, a protein required for accumulation and proper secretion of another translocon component, EseC. The escA gene is located upstream of eseC and the EscA protein has the characteristics of T3SS chaperones. Cell fractionation experiments indicated that EscA is located in the cytoplasm and on the cytoplasmic membrane. Mutation with in-frame deletion of escA greatly decreased the secretion of EseC, while complementation of escA restored the wild-type secretion phenotype. The stabilization and accumulation of EseC in the cytoplasm were also affected in the absence of EscA. Mutation of escA did not affect the transcription of eseC but reduced the accumulation level of EseC as measured by using an EseC-LacZ fusion protein in Ed. tarda. Co-purification and co-immunoprecipitation studies demonstrated a specific interaction between EscA and EseC. Further analysis showed that residues 31-137 of EseC are required for EseC-EscA interaction, Mutation of EseC residues 31-137 reduced the secretion and accumulation of EseC in Ed. tarda. Finally, infection experiments showed that mutations of EscA and residues 31-137 of EseC increased the LD50 by approximately 10-fold in blue gourami fish. These results indicated that EscA functions as a specific chaperone for EseC and contributes to the virulence of Ed. tarda.

EscC is a chaperone for the Edwardsiella tarda type III secretion system putative translocon components EseB and EseD

Edwardsiella tarda is a Gram-negative enteric pathogen that causes disease in both humans and animals. Recently, a type III secretion system (T3SS) has been found to contribute to Ed. tarda pathogenesis. EseB, EseC and EseD were shown to be secreted by the T3SS and to be the major components of the extracellular proteins (ECPs). Based on sequence similarity, they have been proposed to function as the 'translocon' of the T3SS needle structure. In this study, it was shown that EseB, EseC and EseD formed a protein complex after secretion, which is consistent with their possible roles as translocon components. The secretion of EseB and EseD was dependent on EscC (previously named Orf2). EscC has the characteristics of a chaperone; it is a small protein (13 kDa), located next to the translocators in the T3SS gene cluster, and has a coiled-coil structure at the N-terminal region as predicted by COILS. An in-frame deletion of escC abolished the secretion of EseB and EseD, and complementation of Delta escC restored the export of EseB and EseD into the culture supernatant. Further studies showed that EscC is not a secreted protein and is located on the membrane and in the cytoplasm. Mutation of escC did not affect the transcription of eseB but reduced the amount of EseB as measured by using an EseB-LacZ fusion protein in Ed. tarda. Co-purification studies demonstrated that EscC formed complexes with EseB and EseD. The results suggest that EscC functions as a T3SS chaperone for the putative translocon components EseB and EseD in Ed. tarda.

PALEOMONSOONS OF CHINA OVER THE LAST 130,000 YEARS - PALEOMONSOON RECORDS

The characteristics of the modern monsoon climate of China may be used as clues for recognizing the records of paleomonsoon climate. The present paper deals primarily with the various paleomonsoon records of the last 130,000 years in the southeast monsoon area. These records mainly come from the following three fields: (i) the historical, (ii) the geological, including loess-paleosol sequence, deserts, lakes, snowlines, timberlines, the phenomena of continental desertization and so on, and (iii) the biological, presented by vegetation a.d mammals. Among these records, the loess-paleosol sequence in the Loess Plateau reflects a climatic history characterized by alternation of two different climatic periods when the Asian winter monsoon and summer monsoon showed pronounced effects on environment, respectively.

Seismic profiles across the middle Tan-Lu fault zone in Laizhou Bay, Bohai Sea, eastern China

The stratigraphic architecture, structure and Cenozoic tectonic evolution of the Tan-Lu fault zone in Laizhou Bay, eastern China, are analyzed based on interpretations of 31 new 2D seismic lines across Laizhou Bay. Cenozoic strata in the study area are divided into two layers separated by a prominent and widespread unconformity. The upper sedimentary layer is made up of Neogene and Quaternary fluvial and marine sediments, while the lower layer consists of Paleogene lacustrine and fluvial facies. In terms of tectonics, the sediments beneath the unconformity can be divided into four main structural units: the west depression, central uplift, east depression and Ludong uplift. The two branches of the middle Tan-Lu fault zone differ in their geometry and offset: the east branch fault is a steeply dipping S-shaped strike-slip fault that cuts acoustic basement at depths greater than 8 km, whereas the west branch fault is a relatively shallow normal fault. The Tan-Lu fault zone is the key fault in the study area, having controlled its Cenozoic evolution. Based on balanced cross-sections constructed along transverse seismic line 99.8 and longitudinal seismic line 699.0, the Cenozoic evolution of the middle Tan-Lu fault zone is divided into three stages: Paleocene-Eocene transtension, Oligocene-Early Miocene transpression and Middle Miocene to present-day stable subsidence. The reasons for the contrasting tectonic features of the two branch faults and the timing of the change from transtension to transpression are discussed. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.

迟缓爱德华氏菌III型分泌系统(T3SS)输送器蛋白及分子伴侣的研究

迟缓爱德华氏菌（Edwardsiella tarda）是重要的革兰氏阴性致病菌，可以感染包括人类在内的多种动物。由迟缓爱德华氏菌引发的爱德华氏菌病已经在许多水产养殖动物中被发现，每年给淡水和海水水产养殖业带来巨大的损失。目前为止对于迟缓爱德华氏菌病的防治以化学治疗为主，疫苗的研究还在进行中。III型分泌系统（T3SS）是E. tarda重要的致病因子，虽然T3SS基因簇的结构及部分基因的功能得到了初步研究，但其作用机制还未得到阐明。本研究着重开展了迟缓爱德华氏菌T3SS输送器蛋白EseC的分子伴侣的鉴定及功能研究，并对输送器蛋白及其免疫功能进行了初步探讨，希望进一步地了解T3SS在E. tarda致病中的功能及其在疫苗研制中的作用。 一、迟缓爱德华氏菌III型分泌系统（T3SS）输送器蛋白EseC分子伴侣的鉴定和功能研究 以前的工作表明，EseB、EseC和EseD蛋白是E. tarda T3SS输送器蛋白的组成成分，在分泌到细菌细胞外后可以组成输送器装置。分子伴侣对于输送器蛋白的稳定和分泌具有重要的作用，EscC已经被鉴定为EseB和EseD的分子伴侣，而EseC的分子伴侣还没有得到鉴定。在本实验中，我们以EseC作为研究对象，主要开展了EseC分子伴侣鉴定的研究。 生物信息学分析表明，在E. tarda T3SS基因簇上的escA基因与eseC相邻，其编码的蛋白形成一个大的螺旋结构，为分子量较小（17.5kD）的酸性蛋白（pI 4.79），并与已鉴定的分子伴侣具有序列的同源性，这些符合细菌T3SS分子伴侣的特征。研究发现，EscA蛋白分布在细菌的细胞质和细胞膜上。在escA基因缺失后，大大降低了EseC分泌到细菌细胞外的量，同时EseC蛋白在细菌细胞质中的积聚量也减少，当escA基因缺失突变株得到escA基因互补后，EseC的分泌和在细胞质内的积聚恢复到了野生型菌株水平。氯霉素阻断蛋白质合成的实验发现，当细菌不表达EscA的情况下，EseC蛋白逐渐降解，说明了EscA可以影响EseC在胞质中的稳定。蛋白体外结合试验和免疫共沉淀实验发现，EseC和EscA在体外可以结合，在细菌细胞质中也可以相互结合，表明EseC和EscA可以相互作用。上述结果表明，EscA是EseC的分子伴侣。 在确定了EscA是EseC的分子伴侣之后，我们进一步确定EscA对EseC表达的影响，以及两者相互作用的结构域。通过检测转录水平和翻译水平的EseC-LacZ融合蛋白表达情况，发现在EscA缺失的情况下，EseC的转录水平没有变化，而翻译水平下降，表明EscA对EseC的影响在转录后水平。通过构建含有部分结构域缺失的escA或eseC的体外共表达体系，并进行Western blot分析，确定了EseC的31-137氨基酸序列为与EscA结合的区域，而在EscA中并没有找到与EseC结合的区域。EseC的31-137氨基酸片段缺失后，EseC的分泌和在E. tarda细菌细胞中的积聚下降，其下降幅度与escA突变株相当，进一步表明EseC的31-137氨基酸为与EscA相互作用的区域。最后人工感染实验表明，分子伴侣EscA及其与EseC的相互作用对E. tarda的致病力有影响。 二、迟缓爱德华氏菌T3SS输送器蛋白的研究 一些研究表明，T3SS在细菌与宿主相互作用的过程中表达，在体外诱导的条件下也可表达。为了确定E. tarda T3SS体外诱导表达的条件，我们检测了不同培养温度、pH条件下，E. tarda T3SS输送器蛋白表达的情况。研究表明，37°C条件下，E. tarda生长快，T3SS的输送器蛋白表达较低；28°C条件下，T3SS的输送器蛋白表达最高，而在20°C条件下，没有检测到T3SS输送器蛋白的表达。在28°C和37°C的培养条件下，中性和碱性相对酸性来说适合细菌的生长和T3SS输送器蛋白的表达。我们分析了E. tarda野生型和输送器蛋白突变株中的输送器蛋白的细胞分布，并据此推测输送器形成的机制。单一输送器蛋白的缺失不影响其它两个输送器蛋白的积聚，而输送器蛋白的分泌之间存在一定的相互影响。 通过检测输送器蛋白突变株ΔeseB, ΔeseC, ΔeseD生长、泳动、自凝聚和溶血能力的变化，发现在输送器蛋白基因缺失后，体外培养的E. tarda的生长速度变慢，泳动、自凝聚和溶血能力也变弱，说明了输送器蛋白在细菌的生长和功能行使中的重要作用。 为了检测输送器蛋白的免疫保护效果，我们克隆了eseD基因，将其在表达菌株BL21(DE3)中进行表达，并将重组表达的EseD蛋白经Ni-NTA树脂进行纯化。以EseD纯化蛋白作为蛋白抗原对大菱鲆进行注射，EseD蛋白表现出了对鱼类的免疫原性，其抗体效价在第7周达到了最高，为1：5120。攻毒实验表明该蛋白对于保护大菱鲆免疫E. tarda的感染具有帮助作用，在105cfu攻毒浓度下大菱鲆的相对存活率(RPS)为62.5%。结果说明EseD蛋白可以作为蛋白抗原疫苗的候选，并能够在保护鱼类免疫爱德华氏菌病中发挥作用。

热带西太平洋环流动力结构分析与模拟

热带西太平洋环流是副热带环流与热带环流关键分量，毗邻西太平洋暖池，对暖池的形成与变化有重要的作用。然而，目前为止，热带西太平洋环流还有许多问题，包括动力结构还不清楚。因此，论文针对热带西太平洋环流的研究不仅在太平洋环流动力学上有理论意义，而且对气候变化的研究和预测也具有理论和实用价值。 太平洋北赤道流分叉是大洋，特别是太平洋西部边界流海域的一个非常突出的环流现象，它是大洋中副热带大流环和热带流环的发源地，很大程度上决定着海盆尺度的大洋环流结构，在大洋环流动力学上具有非常重要的意义和地位；同时它决定着大洋西边界区质量、热量的经向输送，进而对气候变化产生重要影响，是气候系统中不可忽视的重要分量。因此，北赤道流分叉的研究，不仅具有在海洋动力学上科学意义，而且对气候变化和预测也有实践意义。 从30年代至今，关于北赤道流分叉的研究有两种，一是根据实际观测水文数据，二是由数值模拟结果得出结论。用观测数据做出的结果，相对比较接近实际，但资料的分辨率较差，会引起估算结果的偏差；数值模拟结果有较高的时空分辨率，但由于模式本身的某些缺点会导致结果偏离实际。目前为止，诸多有关北赤道流分叉的结果，如分叉纬度变化的结论很不一致。所以，如何找到一种高时空分辨率的数据或提出一个比较符合物理实际并得到实测数据验证的数值模式是研究北赤道流分叉的关键。 本文用1992年10月到2004年12月高时空分辨率的卫星高度计数据，通过计算迹线的方法，确定了北赤道流分叉的纬度。结果表明，年平均分叉纬度约在13.4°N. 关于北赤道流分叉的季节变化，6月份发生在最南端（12.9°N），12月份发生在最北端（14.1°N）。12年的平均结果显示，7月份的分叉纬度比6月份和8月份明显偏大，这是局地风应力旋度导致的结果。本文同时研究了北赤道流分叉的年际变化，结果表明在厄尔尼诺年，北赤道流分叉纬度北移，在拉尼娜年，分叉纬度南移。 在热带西太平洋地区，特别是西边界流区和印度尼西亚贯通流邻近海域，岛屿众多，地形非常复杂，历史水文数据和测流数据又极少，所以几乎无法用分析观测数据的方法求得这一海域海洋环流，特别是次表层环流结构的深刻了解。因此，本文利用一个既适用于开阔大洋又适宜于地形变化剧烈海域的混合坐标海洋模式HYCOM，模拟了热带西太平洋环流，特别是西边界流及其相关海流，如，新几内亚沿岸潜流、棉兰老潜流、赤道潜流和印度尼西亚贯通流的气候态及其月、季变化。模式结果再现了该海域主要流系及其季节变化，模拟得到的海面高度场与卫星高度计数据基本一致；模拟所得的诸多关键断面上的海流、温度和盐度结构与实地观测数据（Johnson et al., 2002）有良好的一致性，说明本文的HYCOM模拟结果是比较可信、可靠的，可以用来做西太平洋环流分析用。本文得到结果如下： （1）赤道潜流究竟起源于何处，是赤道环流动力学上一个重要问题。鉴于实测数据缺乏和赤道潜流起源邻近海域地形复杂，相关研究很少，仅有的几项研究结果认为赤道潜流起源于135－137°E。本文一系列经向跨赤道断面的纬向流速模拟结果表明，赤道潜流最西源于129－130°E之间；另外，事实上，从200米层水平环流的模拟结果来看，赤道潜流有4个源头，各季有所不同：(i) 新几内亚沿岸潜流在135°E附近汇入赤道潜流；与Tsuchiya et al.（1989）结论相同；(ii) 来自棉兰老海流，这与Lu and McCreary（1995），Gu and Philander（1997）结论相同；(iii) 南海水经民都洛海峡、苏禄海和苏拉威西海西部由哈马黑拉岛以北进入赤道潜流，特别是，在春、夏、秋季；(iv) 印度洋海水经班达海和马鲁古海沿苏拉威西东岸北上沿哈马黑拉岛以东汇入赤道潜流（特别是春季）。所以，赤道潜流就水源来说，它有来自南海、印度洋和棉兰老以东的海水，就其起源来说，还是应该算从129－130°E开始的。 （2）棉兰老潜流发现于80年代末，尽管棉兰老潜流的起源对这一海域环流动力学非常重要，但由于资料缺乏，其起源的研究甚少。本文的模拟结果表明棉兰老潜流似乎有一部分水来自棉兰老海流，这主要在300－500米层。但更重要的是，从马鲁古海西边界（苏拉威西岛以东）向北的一支流更是棉兰老潜流的重要水源，说明棉兰老潜流的水源有相当部分是来自南半球，在600，700米层，特别是800，900和1000米层，棉兰老海流流速急剧减小至几乎看不到，而棉兰老潜流非常突出，其水源主要来自南半球苏拉威西岛东部向北的流动。至于棉兰老潜流的去处，500，600米层的模拟结果显示，棉兰老潜流在12－13°N附近，一大部分向东流去，一小部分向南加入棉兰老海流。在700米层以下，棉兰老潜流则在12°N向东流去，这与Hu and Cui（1989, 1991）和Wang and Hu（1998）的结果一致。 （3）关于印度尼西亚贯通流。HYCOM模拟的印度尼西亚贯通流年平均状况指出：250米以浅，印度尼西亚贯通流由西太平洋主要经由望加锡海峡进入东印度洋；300米以深，印度尼西亚贯通流反向，由东印度洋经由弗罗勒斯海、班达海和马鲁古海的西部边界进入太平洋。由200米层环流可以看出，从民都洛海峡南下的南海水是进入望加锡海峡构成印度尼西亚贯通流的主要的来源，另一小部分来自棉兰老海流。 （4）关于黑潮南海分支。在本文的模拟结果中，一年四季都有明显的黑潮分支由吕宋北端向西北进入南海后，沿大约21°N附近向西南流动，宽约100－200公里，深达300－400米，最大流速一般可达20厘米/秒，最大在冬季，可达40厘米/秒，流量约为6.5Sv，冬季强，5、9月份偏弱。证明了仇德忠、杨天鸿、郭忠信（1984）和郭忠信、杨天鸿、仇德忠（1985）关于南海黑潮分支存在的论述，并在一定程度上定量的解释了其季节变化规律。