二(2-乙基己基)膦酸从硫酸溶液中萃取钪(Ⅲ)的机理研究

本文研究了二(2-乙基己基)膦酸的正庚烷溶液在硫酸介质中萃取抗(Ⅲ)和硫酸诉平衡规律。通过IR、NMR测定和饱和法研究,提出了不同硫酸浓度下钪(Ⅲ)和硫酸的萃取机理。研究了不同温度对萃取平衡的影响,并分别计算了萃取过程的热力学函数。

用打点式记录仪绘制穆斯堡尔谱

本文介绍一种把打点式长图自动平衡记录仪与FH451-1024道分析器连接起来的具体方法和原理。方法简单易行、准确可靠、经济适用;对于一个由500点组成的穆斯堡尔谱,15min就可绘出完整图形。

Intergeneric conjugation in holomycin-producing marine Streptomyces sp strain M095

Marine Streptomyces are potential candidates for novel natural products and industrial catalysts. In order to set up biosynthesis approach for a holomycin-producing strain M095 isotated from Jiaozhou Bay, China, a genetic transformation system was established using intergeneric conjugation. The plasmid pIJ8600 consists of an origin of replication for Escherichia coli, a phage integrase directing efficient site-specific integration in bacterial chromosome, thiostrepton-induced promoter and an attP sequence. Using E. coli ET12567 (pUZ8002) carrying pIJ8600 as a conjugal donor, while it was mated with strain M095, pIJ8600 was mobilized to the recipient and the transferred DNA was also integrated into the recipient chromosome. The frequency of exconjugants was 1.9 +/- 0.13 x 10(-4) per recipient cell. Analysis of eight exconjugants showed pIJ8600 was stable integrated at a single chromosomal site (attB) of the Streptomyces genome. The DNA sequence of the attB was cloned and shown to be conserved. The results of growth and antimicrobial activity analysis indicated that the integration of pIJ8600 did not seem to affect the biosynthesis of antibiotics or other essential amino acids. To demonstrate the feasibility of above gene transfer system, the allophycocyanin gene (apc) from cyanobacterium Anacystis nidulans UTEX625 was expressed in strain M095, and the results indicated heterologous allophycocyanin could be expressed and folded effectively. (c) 2006 Elsevier GmbH. All rights reserved.

Inter-simple sequence repeat (ISSR) analysis of genetic variation of Chondrus crispus populations from North Atlantic

ISSR analysis was used to investigate genetic variations of 184 haploid and diploid samples from nine North Atlantic Chondrus crispus Stackhouse populations and one outgroup Yellow Sea Chondrus ocellatus Holmes population. Twenty-two of 50 primers were selected and 163 loci were scored for genetic diversity analysis. Genetic diversity varied among populations, percentage of polymorphic bands (PPB) ranged from 27.0 to 55.8%, H(Nei's genetic diversity) ranged from 0.11 to 0.20 and I(Shannon's information index) ranged from 0.16 to 0.30. Estimators PPB, H and I had similar values in intra-population genetic diversity, regardless of calculation methods. Analysis of molecular variance (AMOVA) apportioned inter-population and intra-population variations for C crispus, showing more genetic variance (56.5%) occurred in intra-population, and 43.5% variation among nine populations. The Mantel test suggested that genetic differentiation between nine C. crispus populations was closely related with geographic distances (R = 0.78, P = 0.002). Results suggest that, on larger distance scale (ca. > 1000 km), ISSR analysis is useful for determining genetic differentiations of C crispus populations including morphologically inseparable haploid and diploid individuals. (c) 2007 Elsevier B.V. All rights reserved.

Dissection and localization of the immunostimulating domain of Edwardsiella tarda FliC

Bacterial flagellin is known to induce potent immune response in vertebrate systems via the toll-like receptor (TLR) 5. As a result, flagellin has been studied extensively as a vaccine adjuvant. In a previous study, we examined the vaccine and adjuvant potentials of the flagellin (FliC) of the fish pathogen Edwardsiella tarda. We found that E. tarda FliC induced low protective immunity by itself but could function as a molecular adjuvant and potentiate the specific immune response induced by the E. tarda antigen Eta6. Since FliC is a large protein and organized into distinct structural domains, we wondered whether the immunostimulating effect observed with the full-length protein could be localized to a certain region. To investigate this question, we in the present study dissected the FliC protein into several segments according to its structural features: (i) N163, which consists of the conserved N-terminal 163 residues of FliC; (ii) M160, which consists of the variable middle 160 residues; (iii) C94, which consists of the conserved C-terminal 94 residues; (iv) NC257, which is an artificial fusion of N163 and C94. To examine the adjuvanticity of the FliC fragments, DNA vaccine plasmids expressing FliC fragments in fusion with Eta6 were constructed and used to immunize Japanese flounder. The results showed that N163 produced the best adjuvant effect, which, in respect to improvement in the relative percent survival of the vaccinated fish, was comparable to that of the full-length FliC. None of the other FliC fragments exhibited apparent immunopotentiating effect. Further analysis showed that N163 enhanced the production of serum specific antibodies and, like full-length FliC, significantly upregulated the expression of the genes that are possibly involved in innate and adaptive immunity. These results indicate that N163 is the immunodominant region of FliC and suggest that E. tarda FliC may induce immune responses in Japanese flounder via mechanisms alternative to that involving TLR5. (C) 2010 Elsevier Ltd. All rights reserved.

Isolation and characterization of the oxygen-evolving photosystem II complex from the economical red alga Bangia fusco-purpurea

The highly pure and active photosystem II (PSII) complex was isolated from Bangia fusco-purpurea (Dillw) Lyngb., an important economic red alga in China, through two steps of sucrose density gradient ultracentrifugation and characterized by the room absorption and fluorescence emission spectra, DCIP (2,6-dichloroindophenol) reduction, and oxygen evolution rates. The PSII complex from B. fusco-purpurea had the characteristic absorption peaks of chlorophyll (Chl) a (436 and 676 nm) and typical fluorescence emission peak at 685 nm (Ex = 436 nm). Moreover, the acquired PSII complex displayed high oxygen evolution (139 mu mol O-2/(mg Chl h) in the presence of 2.5 mM 2,6-dimethybenzoqinone as an artificial acceptor and was active in photoreduction of DCIP (2,6-dichloroindophenol) by DPC (1,5-diphenylcarbazide) at 163 U/(mg Chl a h). SDS-PAGE also suggested that the purified PSII complex contained four intrinsic proteins (D1, D2, CP43, and CP47) and four extrinsic proteins (33-kD protein, 20-kD protein, cyt c-550, and 14-kD protein).

Development of expressed sequence tags from the bay scallop, Argopecten irradians irradians

The bay scallop, Argopecten irradians irradians, introduced from North America, has become one of the most important aquaculture species in China. Inan effort to identify scallop genes involved in host defense, a high-quality cDNA library was constructed from whole body tissues of the bay scallop. A total of 5828 successful sequencing reactions yielded 4995 expressed sequence tags (ESTs) longer than 100 bp. Cluster and assembly analyses of the ESTs identified 637 contigs (consisting of 2853 sequences) and 2142 singletons, totaling 2779 unique sequences. Basic Local Alignment Search Tool (BLAST) analysis showed that the majority (73%) of the unique sequences had no significant homology (E-value >= 0.005) to sequences in GenBank. Among the 748 sequences with significant GenBank matches, 160 (21.4%) were for genes related to metabolism, 131 (17.5%) for cell/organism defense, 124 (16.6%) for gene/protein expression, 83 (11.1%) for cell structure/motility, 70 (9.4%) for cell signaling/communication, 17 (2.3%) for cell division, and 163 (21.8%) matched to genes of unknown functions. The list of host-defense genes included many genes with known and important roles in innate defense such as lectins, defensins, proteases, protease inhibitors, heat shock proteins, antioxidants, and Toll-like receptors. The study provides a significant number of ESTs for gene discovery and candidate genes for studying host defense in scallops and other molluscs.

黄河河口泥沙扩散及周围海区岸滩稳定性研究

本文根据历年来黄河口及邻近海域的沉积物、悬浮体调查资料（1961年3月-10月、1984年、1989年枯、洪季（笔者参加）等及海岸带调查）；1855年以来的海图资料；1975年以来逐年卫片资料及黄河口海域遥感卫片解译分析报告等资料进行了分析、整理。同时，本文进行了如下工作：（1）对黄河口海区悬浮泥沙的光谱特征进行了野外实测、室内分析；分析了黄河河水的光谱特征；（2）野外测量了莱州湾南岸海滩滩面物质光谱反射特征，对典型样品取样，分析其粒径及其与光谱反射的关系；（3）分析了自1975年以来黄河口海域的卫片，运用计算机处理CCT；（4）对1961年、1989年底怪沉积物粒度参数及粘、砂含量作了模糊数学分析；（5）对黄河三角洲古岸线、水深作了对比，并用卫片资料分析岸线（现代）的动态变化；（6）对黄河三角洲岸滩进行了模糊动态分类。本文定量分析悬浮泥沙含量与光谱反射峰值波长的关系，得出在黄河口邻近海域、悬沙含量跨度大的地区，在用卫星资料定量计算悬沙含量时，应用分段式回归方程式：在高含量区，以TM4解译较好，相反则用TM3解译为宜。本文首次在该地区用卫星遥感资料与准同步海上观察资料进行相关分析，两者相关系较高，其中以TM4尤高些。针对大气程辐射对卫星资料的影响，提出了一种简易的大气校正方法，取得较好的结果。同时，结合不同时相的卫片分析，我们对黄河口海域泥沙分布规律及其影响因素作了详细的论叙。对1961年和1989年5月两次表层底质的粒度参数及粘、砂含量等要素进行模糊分类，得出黄河泥沙扩散的主要方向在1961年时，主要向北、西北、西及东北，少量向东、东南方向扩散。1989年黄河泥沙的扩散方向主要为东北、东南、西南及向东，少量泥沙向西北沿三角洲岸滩扩散。不同时期实测泥沙分布，岸线变化及卫片的泥沙分布型式证实了上述结论。本文首次研究了莱州湾潮滩表层沉积物粒径组成与光谱反射率的定量关系，得出其最侍研究波段。对不同时期地形图的岸线，等深线、坡度变化的对比分析，得出不同岸段的变化特征。用卫片对岸线动态的定量分析表明，仅在河口等快速变化的地区以及较长时段的岸线变化情况适用，而在变化较小的岸段以及时段较短时，其计算结果误差较大。本文最后提出一种考虑多因素综合作用、并能突出主导因素的模糊动态分类，分类结果与实际情况较为吻合，它为海岸动态性的研究提出了新方向。

The effect of acute salinity change on white spot syndrome (WSS) outbreaks in Fenneropenaeus chinensis

In order to observe the effect of salinity on disease resistance and white spot syndrome virus (WSSV) proliferation in Fenneropenaeus chinensis, shrimps with latent WSSV were subjected to two acute salinity changes from the original salinity of 22 ppt to 18 and 14 ppt in an hour, respectively. The total haemocyte count (THC) of the challenged group showed no evident change under salinity adjustments, but the phenoloxidase (PO) index declined significantly (P<0.05) corresponding to continuing acute salinity changes from the 24th to the 72nd hour. According to the WSSV load detected by quantitative real-time PCR method, it was found that WSSV carried by the challenged group and control group were significantly different (P<0.05); acute salinity change from 22 to 14 ppt led to the WSSV carried in the challenged group being significantly higher (P<0.05) than that of those surviving in 22 ppt, but salinity change from 22 to 18 ppt had no such effect. At the end of the 72-h experiment, the challenged group subjected to salinity change from 22 to 14 ppt had nearly 3 times the WSSV load as the control group with no salinity change. Therefore, salinity changes over a particular range could result in a decrease of immunocompetence and obvious WSSV proliferation in the shrimps, leading to white spot syndrome developing from a latent infection to an acute outbreak. (C) 2005 Elsevier B.V All rights reserved.

Antimicrobial activity of hydroxylbenzenesulfonailides derivatives of chitosan, chitosan sulfates and carboxymethyl chitosan

Chitosan, carboxymethyl chitosan (CIVICS) and chitosan sulfates (CSS) with different molecular weight were modified by reacting with 4-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride or 2-hydroxyl-5-chloride-1,3 -benzene-disulfo-chloride to give 12 kinds of new hydroxylbenzenesulfonailides derivatives of them. The preparation conditions of the derivatives were discussed in this paper, and their structures were characterized by FT-IR and C-13 NMR spectroscopy. The solubility of the derivatives was measured in the experiment. In addition, their antimicrobial activities against four bacteria and five crop-threatening pathogenic fungi were tested in the experiment. Besides, the rule and mechanism of their antibacterial activities were discussed in this paper. (C) 2009 Published by Elsevier B.V.