网间交联型增韧环氧树脂/蓖麻油聚氨酯互穿网络聚合物的动态力学性能和形态结构

以增韧环氧树脂(TEP)和蓖麻油聚氨酯[PU(CO)]形成的互穿网络聚合物(IPN),两网络间具有一定数量的交联点,在一定组成下,该IPN的tanδ-T曲线半峰宽达100℃,tanδ最大值接近1,阻尼性能良好。形态研究表明,该IPN既有增韧环氧树脂本身的两相结构,又有IPN的两相结构。

The genomic structure, alternative splicing and immune response of Chlamys farreri thioester-containing protein

MEP is a member of thioester-containing protein (TEP) family found in Zhikong scallop Chlamys farreri and is involved in innate immunity against invading microbes. In the present study, the genomic DNA of CfTEP was cloned and characterized. The genomic DNA sequence of CfTEP consisted of 40 exons and 39 introns spanning 35 kb with all exon-intron junction sequences agreeing with the GT/AG consensus. The genomic organization of CfTEP was similar to human and mouse 0 rather than ciona C3-1 and Drosophila dTEP2. By RT-PCR technique, seven different cDNA variants of CfTEP (designated as CfTEP-A-CfTEP-G) were cloned from scallop gonad. CfTEP-A-CfTEP-F were produced by alternative splicing of six mutually exclusive exons (exons 19-24), respectively, which encoded the highly variable central region. While in CfTEP-G, the deletion of all the six exons introduced a new translation stop site and might trigger nonsense mediated decay (NMD). The mRNA expression and the proportion of the seven CfTEP variant transcripts were examined in the gonad of scallops after bacterial challenge. The fragments containing the highly variable central region of UTEP were amplified by RT-PCR and a 100 positive clones were sequenced randomly. The expression profiles of the seven MEP variants were different and displayed the sex and bacteria dependent manner. In the blank, sea water and Listonella anguillarum challenged subgroups of male scallops, all the transcripts detected were CfTEP-G isoform. In the Micrococcus luteus challenged subgroup, the isoforms expressed and their proportions were CfTEP-F (54%), CfTEP-B (23%), CfTEP-A (10%), CfTEP-C (7%) and CfTEP-E (6%). However, in the gonad of female scallops, only CfTEP-A were found in blank and sea water challenged subgroups. After L anguillarum or M. luteus challenge, four and five isoforms were detected, respectively, with CfTEP-F isoform being the most one in the both subgroups. These results suggested that the evolution of TEP genes was very complex, and that the diverse CfTEP transcripts generated by alternative splicing played an important role as pattern recognition receptors in the innate immune defense of scallops. (C) 2009 Elsevier Ltd. All rights reserved.

Molecular cloning and characterization of a thioester-containing protein from Zhikong scallop Chlamys farreri

Thioester-containing proteins are a family of proteins characterized by the unique intrachain beta-cysteinyl-gamma-glutamyl thioester, which play important roles in innate immune responses. The cDNA of Zhikong scallop Chlamys farreri thioester-containing protein (designated as CfTEP) was cloned by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of CfTEP was of 4616 bp, consisting of a 5 '-terminal untranslated region (UTR) of 30 bp and a 3 ' UTR of 140 bp with a polyadenylation signal sequence AATAAA and a poly(A) tail. The CfTEP cDNA encoded a polypeptide of 1481 amino acids with the theoretical isoelectric point of 5.98 and the predicted molecular weight of 161.4 kDa. The deduced amino acid sequence of CfTEP contained the canonical thioester motif GCGEQ, nine potential N-glycosylation sites and a C-terminal distinctive cysteine signature. It also contained a presumed catalytic histidine and proteolytic cleavage sites that were similar to C3 molecules. The high similarity of CfTEP with the thioester-containing proteins in other organisms, such as the TEPs from insects, the complement component C3, C4, C5 and the protease inhibitor alpha(2)-macroglobulin indicated that CfTEP should be a member of TEP family. The phylogenetic analysis revealed that CfTEP was closely related to TEPs from mollusc, nematodes and insects, and they formed a separate branch apart from the branches of complements factors and alpha(2)-macroglobulins. The spatial expression of CfTEP transcripts in healthy and bacterial challenged scallops was examined by semi-quantitative RT-PCR. The CfTEP transcripts were mainly detected in the tissues of hepatopancreas and gonad, and remarkably up-regulated by Microbial challenge, which suggested that CfTEP was a constitutive and inducible acute-phase protein involved in immune defense. These results provided new insights into the role of CfTEP in scallop immune responses, as well as the evolutionary origin of this important, widespread and functionally diversified family of proteins. (c) 2007 Published by Elsevier Ltd.

东太平洋海隆13°N附近含金属沉积物中的有机碳氮研究

本文根据热液活动对海底沉积环境影响的程度，将海底沉积环境划分为三个部分：热液直接作用区（硫化物分布区），热液间接作用区（含金属沉积物区），正常沉积区。东太平洋海隆13°N附近所取得的三个沉积物柱状样(E271、E272、E53)属于含金属沉积物区，以它们为研究对象（E271和E272是重点研究对象），进行了粒度、粘土矿物、有机碳氮和无机碳分析，并结合已有的测年数据和金属元素含量数据，对含金属沉积物中的有机碳氮进行了系统的讨论。 沉积物无机组分的物源分析表明，沉积物中富含铁锰的组分主要是非晶质或结晶程度较差的铁锰氧化物和氢氧化物。来自于火山灰蚀变的富铁蒙脱石也有一定的贡献，但是含量太少。铁锰氧化物或氧氧化物倾向于集中在细粒的物质中。铁锰含量自下而上的递增趋势反映了热液活动程度增强的趋势。 三个站位沉积物中有机碳的含量都很高，E271、E272 有机碳含量在0.9%-1.5%之间，而E53含量则相对更高，最高可达4.6%。E271、E272自下而上有递增的趋势，它与铁锰的含量有一定的相关性，可能有机质与铁锰之间存在某种联系。有机碳的沉积通量很低，E271上层为4.06mg/ka•cm2 ，下层仅为0.84mg/ ka•cm2。因此沉积物中高有机碳含量显示的高生产力是一种假像，并不能代表古海水表层生产力很高。 C/N值在三个站位的变化情况各有不同。按照常规的把有机质来源分为海洋表层生物与陆源有机碳来源，那么E271和E53站位总体上水生有机碳在总有机碳中居主要成分。E272上层是海洋生物来源占优，下层是陆源生物占优。但是根据热液plume存在细菌和TEP的特性，应该考虑沉积物中有机质是表层生物源和热液影响的生物源。经过假设计算，认为热液影响的生物有机碳源受到热液柱扩散形态的影响，且与热液活动的稳定性有关。因此两相比较，认为该研究区，有机质来源应该选择表生有机碳与受热液影响生物有机碳为两个端元组分。受热液生物影响的程度为E272>E271>E53。 在E272站位沉积物中发现的一些细菌种类与热液喷口区的嗜热细菌相似程度很高，它们可能是随着Plume飘移而迁移，并沉降到沉积物中。它们的存在对有机碳的含量和组成将会产生影响。这是一个热液生物影响沉积物有机碳的直观的证据。 通过Fe、Mn、Al 含量随深度变化的趋势，推断出碳酸钙自下而上减小不是因为热液组份的加入对其含量稀释而成的，应该是沉积环境的改变，导致其溶解度增加所致。 在研究过程中，还对沉积物中有机碳的测定方法进行了探讨，鉴于不同方法之间带来的有机碳数据上的误差，建议建立一种标准的测试方法，便于有机碳数据的比较。计算沉积速率和沉积通量时，对E271用含水量进行了去压实校正。根据计算，当含水量变化很大时，去压实作用是有必要的。

Distribution of calcifying and silicifying phytoplankton in relation to environmental and biogeochemical parameters during the late stages of the 2005 North East Atlantic Spring Bloom

The late stage of the North East Atlantic (NEA) spring bloom was investigated during June 2005 along a transect section from 45 to 66 degrees N between 15 and 20 degrees W in order to characterize the contribution of siliceous and calcareous phytoplankton groups and describe their distribution in relation to environmental factors. We measured several biogeochemical parameters such as nutrients, surface trace metals, algal pigments, biogenic silica (BSi), particulate inorganic carbon (PIC) or calcium carbonate, particulate organic carbon, nitrogen and phosphorus (POC, PON and POP, respectively), as well as transparent exopolymer particles (TEP). Results were compared with other studies undertaken in this area since the JGOFS NABE program. Characteristics of the spring bloom generally agreed well with the accepted scenario for the development of the autotrophic community. The NEA seasonal diatom bloom was in the late stages when we sampled the area and diatoms were constrained to the northern part of our transect, over the Icelandic Basin (IB) and Icelandic Shelf (IS). Coccolithophores dominated the phytoplankton community, with a large distribution over the Rockall-Hatton Plateau (RHP) and IB. The Porcupine Abyssal Plain (PAP) region at the southern end of our transect was the region with the lowest biomass, as demonstrated by very low Chla concentrations and a community dominated by picophytoplankton. Early depletion of dissolved silicic acid (DSi) and increased stratification of the surface layer most likely triggered the end of the diatom bloom, leading to coccolithophore dominance. The chronic Si deficiency observed in the NEA could be linked to moderate Fe limitation, which increases the efficiency of the Si pump. TEP closely mirrored the distribution of both biogenic silica at depth and prymnesiophytes in the surface layer suggesting the sedimentation of the diatom bloom in the form of aggregates, but the relative contribution of diatoms and coccolithophores to carbon export in this area still needs to be resolved.