198 resultados para LDH - C4
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Using an enhanced surface plasmon resonance (SPR) immunosensor, we have determined the concentration of human complement factor 4 (C4). Antibody protein was concentrated into a carboxymethyldextran-modified gold surface by electrostatic attraction force and a simultaneous covalent immobilization of antibody based on amine coupling reaction took place. The sandwich method was applied to enhance the response signal and the specificity of antigen binding assay. The antibody immobilized surface had good response to C4 in the range of 0.02-20 mug/ml by this enhanced immunoassay. The regeneration effect by pH 2 glycine-HC1 buffer was also investigated. The same antibody immobilized surface could be used more than 80 cycles of C4 binding and regeneration. In addition, the ability to determinate C4 directly from serum sample without any purification was investigated. The sensitivity, specificity and reproducibility of the enhanced immunoassay are satisfactory. The results clearly demonstrate the advantages of the enhanced SPR technique for C4 immunoassay.
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考察了SbCl5对杂多酸 (HPA)催化i C4 H10 /C4 H8烷基化反应的修饰作用 ,用Hammett指示剂测定了SbCl5/HPA催化剂的酸强度 .结果表明 ,经SbCl5修饰的HPA的酸强度有所提高 ,SbCl5的加入量、反应温度及反应时间对烷基化油收率及产物分布均有不同的影响.
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采用 Nd( naph) 3- Al( C2 H5) 3- ( t- C4 H9) Cl三组分稀土催化剂进行丁二烯 ( BD) -异戊二烯( IP)的顺式共聚合 ,在聚合过程中引入有机氯代烃 ( RCl) ,以与聚合液中的烷基铝作用生成阳离子活性种 ,引发已生成的共聚物的环化反应及单体的环聚反应 ,得到可溶性无凝胶且含有环聚成分的环化共聚合产物 .考察了 RCl用量、单体组成、稀土催化剂用量、反应温度等对原位环化反应的影响 .以红外光谱、核磁共振光谱对环化产物的结构进行了初步分析 ,确认了环化产物的生成
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In this paper, the effects of rare earth ions (La3+, Eu3+, Dy3+, Yb3+) and their complexes with calmodulin on the activity of lactate dehydrogenase (LDH) were investigated. The results reveal that whether binding with calmodulin or not, rare earth ions show a minor activation effects on LDH when their concentrations are less than 3 mu mol (.) L-1, but indicate some strong inhibitory effects on LDH activity when the concentrations are above 5 mu mol (.) L-1. Calmodulin, which is a calcium-dependent regulator, can stimulate LDH activity and release the inhibitory effects of rare earth ion. Diethylenetriamine pentaacetic acid(DTPA) and its derivatives bisdimethylamide-diethylenetriamine pentaacetic acid (DTPA-BDMA), bisisonicotinyl-diethylenetriamine pentaacetic acid (DTPA-BIN), which are often used as ligands to metal ions, inhibit LDH activity when their concentrations are above 5 mu mol (.) L-1. Calmodulin can also release their inhibitory effects at the same time.
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分别研究了三价稀土离子、稀土离子和钙调蛋白CaM的复合物以及作为稀土离子配体的二乙三胺五乙酸DTPA及其衍生物二乙三胺五乙酸双二甲酰胺 DTPABDMA和二乙三胺五乙酸双异烟肼DTPABIN对乳酸脱氢酶LDH活性的影响。结果表明稀土离子浓度小于3μmol·L-1时对酶活性具有轻微的激活作用离子浓度增大到6μmol·L-1后则开始表现出抑制作用钙调蛋白可以缓解这种抑制作用二乙三胺五乙酸及其衍生物在浓度超过5μmol·L-1 时对酶活性均有抑制这种抑制作用在加入外源的钙调蛋白后也得到缓解。
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[Si(W2O7)(6)](8-) pillared LDH structure hydroxides were synthesized by the method of restructuring of the thermally decomposed hydrotalcite-like compounds for Zn-Al and Mg-Al oxide systems. [P(W2O7)(6)](8-) pillared Ni-Al LDH structure hydroxide was synt
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本文用~(13)C NMR方法研究了水溶液中三价顺磁性稀土离子Ho~(3+)和Yb~(3+)与二肽甘氨酰替亮氨酸之间的相互作用。对稀土诱导位移中的接触位移和偶极位移进行了分离。实验表明,与羧基相连的碳核所受的接触作用很大,因此不能把镱诱导的位移直接用于肽的构象分析。在水溶液中,肽通过羧基与稀土离子配位,在弱酸性条件下肽键和氨基均不参与配位。根据结构因子确定了肽在溶液中的构象,结果表明,分子片段C1-C2-C5-C6,C2-N-C3-C4和C2-C5-C6-C8为反式,而C2-C5-C6-C7和C1-C2-N-C3成旁式。
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The effects of three non-nutrient additives on nonspecific immunity and growth of juvenile turbot (Scophthalmus maximus L.) were studied in this feeding experiment. The five treatments are basal diet alone, basal diets containing three different additives [0.4 g kg(-1) of xylo-oligosaccharides (XOS), 1.3 g kg (-1) of yeast cell wall and 0.8 g kg (-1) of bile acids] individually or in combination. Two hundred and twenty-five turbots (average initial weight 151.3 +/- 11.3 g) were randomly allotted in five treatments with three replicates within each treatment in a 72-day period. Comparing with basal diet group, activities of C3, C4, phagocyte, lysozyme, specific growth rate and feed conversion rate in yeast cell wall, XOS and the combined groups was enhanced significantly (P < 0.05); however, these parameters in bile acid groups were increased slightly (P > 0.05) except for phagocyte (P < 0.05); superoxide dismutase activity in additive groups was not significantly increased (P > 0.05) except for the combined group (P < 0.05). In conclusion, supplementation of yeast cell wall and XOS enhanced the nonspecific immunity of juvenile turbot. Synergistic or additive effect of the three additives was not observed.
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Porphyra haitanensis T. J. Chang et B. F. Zheng (Bangiales, Rhodophyta) is cultivated in China and widely consumed in Asia. To gain more insight into its physiological and biochemical properties, we generated 5318 expressed sequence tags (ESTs) from the sporophyte of P. haitanensis, and upon assembling into a nonredundant set, 2535 sequences were obtained, among which only 32.2% (816) shared certain similarity with published sequences (Nr and KOG). Functional classification of such ESTs revealed that most of the transcripts were related to its conservative biological metabolism, and P. haitanensis most likely possesses cyanide-resistant respiration and a C4-like carbon-fixation pathway, both of which have never been reported in a rhodophyte before. Twenty-eight percent of the nonredundant gene clusters exhibited significant similarity to those from P. yezoensis Ueda sporophytes, and 16 genes up-regulated in P. yezoensis sporophytes were also expressed abundantly in P. haitanensis. Codon usage analysis indicated that exposure to high GC pressure might occur during evolution of P. haitanensis. These findings represent the most extensive collection of ESTs from P. haitanensis to date, and all the ESTs in this study have been submitted to GenBank (accession nos. DN604790-DN608469, EG016226-EG018540).
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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.
Impact of spatial resolution and spatial difference accuracy on the performance of Arakawa A-D grids
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This paper alms at illustrating the impact of spatial difference scheme and spatial resolution on the performance of Arakawa A-D grids in physical space. Linear shallow water equations are discretized and forecasted on Arakawa A-D grids for 120-minute using the ordinary second-order (M and fourth-order (C4) finite difference schemes with the grid spacing being 100 km, 10 km and I km, respectively. Then the forecasted results are compared with the exact solution, the result indicates that when the grid spacing is I kin, the inertial gravity wave can be simulated on any grid with the same results from C2 scheme or C4 scheme, namely the impact of variable configuration is neglectable; while the inertial gravity wave is simulated with lengthened grid spacing, the effects of different variable configurations are different. However, whether for C2 scheme or for C4 scheme, the RMS is minimal (maximal) on C (D) grid. At the same time it is also shown that when the difference accuracy increases from C2 scheme to C4 scheme, the resulted forecasts do not uniformly decrease, which is validated by the change of the group A velocity relative error from C2 scheme to C4 scheme. Therefore, the impact of the grid spacing is more important than that of the difference accuracy on the performance of Arakawa A-D grid.
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In this study we describe the velocity structure and transport of the North Equatorial Current (NEC), the Kuroshio, and the Mindanao Current (MC) using repeated hydrographic sections near the Philippine coast. A most striking feature of the current system in the region is the undercurrent structure below the surface flow. Both the Luzon Undercurrent and the Mindanao Undercurrent appear to be permanent phenomena. The present data set also provides an estimate of the mean circulation diagram (relative to 1500 dbar) that involves a NEC transport of 41 Sverdrups (Sv), a Kuroshio transport of 14 Sv, and a MC transport of 27 Sv, inducing a mass balance better than 1 Sv within the region enclosed by stations. The circulation diagram is insensitive to vertical displacements of the reference level within the depth range between 1500 and 2500 dbar. Transport fluctuations are, in general, consistent with earlier observations; that is, the NEC and the Kuroshio vary in the same phase with a seasonal signal superimposed with interannual variations, and the transport of the MC is dominated by a quasi-biennial oscillation. Dynamic height distributions are also examined to explore the dynamics of the current system.
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[ 1] Intraseasonal variability of Indian Ocean sea surface temperature (SST) during boreal winter is investigated by analyzing available data and a suite of solutions to an ocean general circulation model for 1998 - 2004. This period covers the QuikSCAT and Tropical Rainfall Measuring Mission (TRMM) observations. Impacts of the 30 - 90 day and 10 - 30 day atmospheric intraseasonal oscillations (ISOs) are examined separately, with the former dominated by the Madden-Julian Oscillation (MJO) and the latter dominated by convectively coupled Rossby and Kelvin waves. The maximum variation of intraseasonal SST occurs at 10 degrees S - 2 degrees S in the wintertime Intertropical Convergence Zone (ITCZ), where the mixed layer is thin and intraseasonal wind speed reaches its maximum. The observed maximum warming ( cooling) averaged over ( 60 degrees E - 85 degrees E, 10 degrees S - 3 degrees S) is 1.13 degrees C ( - 0.97 degrees C) for the period of interest, with a standard deviation of 0.39 degrees C in winter. This SST change is forced predominantly by the MJO. While the MJO causes a basin-wide cooling ( warming) in the ITCZ region, submonthly ISOs cause a more complex SST structure that propagates southwestward in the western-central basin and southeastward in the eastern ocean. On both the MJO and submonthly timescales, winds are the deterministic factor for the SST variability. Short-wave radiation generally plays a secondary role, and effects of precipitation are negligible. The dominant role of winds results roughly equally from wind speed and stress forcing. Wind speed affects SST by altering turbulent heat fluxes and entrainment cooling. Wind stress affects SST via several local and remote oceanic processes.
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本文以山东近海野生和养殖牙鲆Paralichthys olivaceus(T.& S.)为研究对象,采用同工酶电泳和随机扩增多态性DNA(RAPD)两种方法,进行了群体遗传学研究;另外,用PCR扩增了牙鲆、桂皮斑鲆Pseudorhombus cinnamomeus(T.& S.)、石鲽Kareius bicoloratus,Basilewsky和大菱鲆Psetta maxima 4种鲽形目鱼类mtDNA 16s rRNA基因区的部分片段,采用生物信息、学方法构建了鲽形目分子系统树。主要结果如下:1.首先建立了适于牙鲆同工酶分析的水平淀粉凝胶和垂直聚丙烯酰胺凝胶电泳系统;对获得的牙鲆15种同工酶基本酶谱进行了生化遗传分析,进而对自然和养殖群体的生化遗传结构进行了分析,共记录了29个基因座位,发现了9个多态座位。2.野生群体的生化遗传参数多态基因座位比例(31.O%)、等位基因平均数(1.38)和群体平均杂合度(0.0802)都明显高于养殖群体(24.1%,1.28,O.0788);在野生群体中有9个多态基因座位,而养殖群体仅7个多态基因座位;其中,除了Cat和Idhp-1(仅养殖群体)(P < 0.05)有显著差异、Ldh-C(P < O.01)完全偏离Hardy-Weinberg定律外,其余多态座位基因频率均符合Hardy-Weinberg遗传平衡定律。野生和养殖群体的遗传相似性系数(I)为0.9877,它们的遗传距离(D)是0.0124;两群体间的遗传分化系数G_(st)为0.0681,D_m为0.01,表明总变异中的6.8%的遗传变异产生于群体间的基因差异。3.采用11个随机引物对20个野生个体和24个养殖个体进行了RAPD群体遗传多样性分析,分别扩增出88条和86条DNA带,片段大小在200-2500bp之间,平均每个引物扩增的带数是7.8-8.0。两个群体的多态座位比例分别是43.2%和34.9%,平均杂合度是0.2739和0.2255,而Shannon遗传多样性指数表明两群体的遗传变异中有88.12%的遗传变异来自种群内,只有11.88%的变异来自群体间。遗传分化指数G_(st)的结果也验证了Shannon遗传多样性指数的结果:总群体的遗传变异中约有12%是由两群体间的基因差异产生的。4.本文对牙鲆两个群体的同一批样品分别采用经典的同工酶方法和RAPD方法进行了较系统的比较分析。发现,RAPD所显示的多态性要比同工酶的高得多,因为大部分RAPD的变异是源于非编码区和重复DNA,可以遍布整个基因组,而同工酶仅是功能基因的产物,只表现编码区的变异。因此,自然选择在同工酶编码区的作用要多于RAPD标记。在遗传相似性系数(I)和遗传距离(D)上,RAPD的分析结果与同工酶的分析结果也是有差异的,用同工酶分析两个群体遗传距离只有0.0124,而用RAPD研究可达0.0508。遗传分化指数的差异也很大,同工酶为0.0681,RAPD为0.1237。5.RAPD和同工酶的分析结果是类似的,即自然群体的多态座位比例和平均杂合度要比养殖群体高,降低幅度在同工酶中界于1.7~22.3%之间,在RAPD中则界于15.9~19.2%之间。这充分证明了养殖群体的遗传多样性水平已有明显的丧失,值得我们注意。6.构建了鲽形目鱼类mtDNA 16S rRNA基因的分子系统树。通过分子克隆法将牙鲆、桂皮斑鲆、大菱鲆和石鲽mtDNA 16S rRNA目的基因片段连接到质粒载体上,经MegaBACE测序仪测序,分别获得了590、595、582和590bp序列,通过生物信息学方法对其进行了序列分析和核酸变异比较,结合NCBI上6种鲽形目鱼类的同源序列探讨了这4种鱼类在鲽形目中的遗传分化和分子系统进化,构建了系统树,其中,桂皮斑鲆的16S rRNA基因在系统树中的位置与物种形态资料的系统演化不相符,而其它三种很好地呈现了它们在鲽形目中的系统位置。同时,可以看出mtDNA 16S rRNA基因片段可以构建一个相对准确的树,特别是NJ树和ML树比较接近,更为客观一些。由比对序列获得的物种之间的遗传距离也基本可以反映种、属、科间的不同变异水平。
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鲳属鱼类是鲈形目中具有很高经济价值的名贵鱼类,广泛分布于我国沿海。我国是鲳鱼产量最高的国家之一,仅1995年产量就达20.9万吨(中国渔业统计年鉴,1995),约占世界鲳鱼达的60%以上.近二、三十年来,由于受传统业资源的过度开发、近海资源不足以及海洋环境污染因素影响,我国四大渔业中的大、小黄鱼及带鱼资源相继衰竭,使年产约20万吨的鲳属鱼类在我国海洋渔业中占据越来越理要的地位,引起了国内外鱼类学家的广泛注意。然而,鲳属鱼类的分布和命名问题,长期以来,国内外专家学者众说纷绘纭、菲衷一是。本文总结的近二百年来有问中国鲳属鱼类分类研究的国内外文献资料,根据中国科学院海洋研究所历年(1951-1998)采集并收藏的以及新补充采集的鲳鱼标本,对我国沿海鲳属鱼类的外部形态(包括体形、体色、鳍、鳞片)、消化器官(包括牙齿、食道侧囊、胃、幽门盲囊、肠、肝)、呼吸器官、感觉器官、骨骼系统(包括脑颅、咽颅、脊椎骨、附肢骨骼)等生化特征作了系统地比较研究,并用支序分类学原理和方法分析了中国鲳属种间的系统发育关第,得到如下结果:1. 中国沿海鲳属鱼分共有5种:银鲳Pampus argenteus (Euphrasen,1788)、翎鲳P. punctatissimus (Temminck et Schlegel, 1845)、灰鲳 P.cinereus (Bloch, 1793) 、中国鲳P. chinensis (Euphrasen, 1788)和珍鲳P. minor Liu et Li, 1998, sp. nov,. 其中银鲳、灰鲳和中国鲳曾多次出现在我国近海地区性鱼类志和地方鱼类志中,本文对它们进物了准确的鉴定和描述,对翎属P. punctatissimus 进行了重新描述,在我国为新记录;论证了珍鲳P. minor为区别于鲳属其它独立有效的一新种。2. 形态学化较研究表明,5种鲳属鱼类在体形、体色、鳍棘、鳍条、牙齿、幽门盲囊、鳃耙、头后部侧线管、 头骨、脊椎骨、耳石等特征方面存在明显的种间差异,可作为鲳属鱼类分类的有效鉴别特征。3.中国沿海的中国鲳P. chinensis (Euphrasen,1788)与印渡洋的瑷鲳 P. ctous (Cuvier et Valenciennes, 1833)形态差异很小,认为P. atous (Cuivier et Valenciennes, 1833) 与P.chinensis (Euphrasen, 1788)可能为同一种,P. atous 应为P. chinesnsis 的同物异名。4.鲳属鱼类的肌浆蛋白酶(Pm)、酯酶(EST)和超氧化物歧化酶(SOD)具有明显的种的特异性,乳酸脱氢酶(LDH)则无种间差异。青岛、上海、厦门和珠海4个取样地点的银鲳的Pm和EST酶谱完全相同,同样,上述4个取地点的瓴鲳Pmt EST 酶谱也完全相同,从生化学的角度证明我国各海区的银鲳的翎鲳各为同一个种。5.银鲳和翎鲳为广盐广域种,我国黄渤海、东海、台湾海峡和地海均有分布,而且种群数量最大;灰鲳和中国鲳分布于我国东海南部、台湾海峡中部以南和南海,为亚暖水种,种数量次之:珍鲳仅分布于台湾海峡南部的大陆沿岸及南海,为暖水种,其种群数量较小,在当在形成一定的渔汛。6.系统发育关系分析表明,中国鲳属鱼类构成一个单群,此属的共同离征有:1)成鱼无腹鳍;2)背鳍鳍条多于31枚;3)臀鳍鳍条多于30 枚;4)背鳍和臀鳍前部鳍条延长;5)下颌牙齿为三峰型; 6)食道侧囊1个;7)食道侧囊内乳突有放射状脚根;8)脊椎骨数目少、眼眶窝大、后颞窝骨显、耳石厚等近祖特征,但它们仍然具有鳃耙数目多、下颌牙禽少等近祖特征,也是较早期分化种;中国鲳具有个体大、背鳍和臀鲳不具鳍棘、背鳍和臀鳍鳍条数目较多、鳃耙数少且短、翼蝶骨较发达等特征,是毗较特化种; 翎鲳和灰鲳具有鳍第鳍棘和脊椎骨数目较多、鳃耙数较少等区同祖征和具有显著延长的背鳍和臀鳍前部鳍条等共同离征,是一对姐妹种。