946 resultados para valet 1948


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Polyethyleneimine-functionalized platinum nanoparticles (PtNPs) with excellent electrochemiluminescence (ECL) properties were synthesized and applied to the amplified analysis of biomolecules. These particles were prepared at room temperature, with hyperbranched polyethyleneimine (HBPEI) as the stabilizer. The UV/Vis absorption spectra and transmission electron microscopy images clearly confirmed the formation of monodisperse PtNPs. Such particles proved to possess high stability against salt-induced aggregation, enabling them to be employed even under high-salt conditions. Owing to the existence of many tertiary amine groups, these particles exhibited excellent ECL behavior in the presence of tris(2.2'-bipyridyl)ruthenium(II). An HBPEI-coated particle possessed an ECL activity that was at least 60 times higher than that of a tripropylamine molecule. Furthermore, these particles could be immobilized on the 3-aminopropyltriethoxysilane-treated quartz substrates to amplify the binding sites for carboxyl groups. Through this approach, PtNPs were applied to the amplified analysis of the hemin/G-quadruplex DNAzyme by using the luminol/H2O2 chemiluminescence method.

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Crystal structure of a novel aryl ether ketone polymer poly(aryl ether ketone ether ketone ketone containing meta-phenyl linkage)(PEKEKmK) was determined by means of WAXD and ED. An orthorhombic unit cell is proposed containing two chains with a=0.772 nm, b=0.604 nm and c=2.572 nm. According to the orthorhombic system, the 10 reflections of this polymer were indexed.

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中国科学院长春应用化学研究所座落在吉林省长春市风景秀丽的南湖之畔,是国内大型综合性化学学科科研机构之一。它的前身是建于30年代的日伪大陆科学研究院,1948年10月长春解放,1948年12月正式建所。全所现有职工1420人,其中学部委员3人,高级科技人员300多人。中级科技人员600多人,全所设有24个研究

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利用AFLP标记对海带在太平洋西北沿岸的6个主要栽培品系和6个野生地理隔离种群进行遗传多样性和亲缘关系分析。通过10对选择性引物总共检测到547个位点。在品系和种群水平,多态性位点比例(P),基因多样性(H)和香农指数(I)在大连野生种群中最高(P: 59.05%; H: 0.2057; I: 0.3062),而在连江栽培品系中最低(P: 9.87%; H: 0.0331; I: 0.0497)。在物种水平(即对所有品系和种群来说),P, H 和I 的值分别是85.01%,0.1948和0.3096。以个体间的相似系数(Dice)和种群间的遗传距离为基础,用非加权类平均法(UPGMA)分别构建个体和种群间的系统树图。AMOVA分析显示,大部分的遗传变异(60.21%)存在于品系和种群间,少部分(39.79%)存在于品系或种群内。遗传分化系数GST的值是0.6226,与FST的值(0.6021)非常接近,基因流(Nm)的值是0.1515,这三个值表明种群(品系)间存在高度的遗传分化。Mantel检验发现6个野生种群的遗传距离或遗传分化与地理距离呈正相关性(相关系数分别是r=0.8870, P=0.007 和 r=0.7962, P=0.011),符合“距离隔离(isolation by distance, IBD)”模型。总体来说,种群(品系)内的遗传多样性处于低到中等水平(大连种群除外),而它们之间的遗传分化程度非常高。 用AFLP和微卫星标记对裙带菜配子体克隆单一交配组合的孢子体后代的遗传一致性进行分析。在这项研究中,建立了2个配子体克隆单一交配系(M1和M2),2个自交系(S1和S2)并采集1个野生种群(W)。11组AFLP引物总共检测到318个位点。M1, M2, S1, S2 和W的多态性位点比例分别是4.7%,0.3%,17.9%,16.4%和36.5%。M1和M2个体间的遗传相似度(95.6-100%)要高于S1和S2(87.7-98.4%)以及W(81.5-92.1%)。在微卫星分析中,用了6个位点。M1在其中的5个位点基因型一致,而在Up-AC-2B2位点显示出不同的基因型。M2在所有6个微卫星位点的基因型都一致。而S1, S2和W都在2个以上的位点检测到不同的基因型。总之,AFLP与微卫星的分析结果一致,即配子体克隆单一交配组合的孢子体后代呈现高度遗传相似性,但也存在细微的差异。 对中国羊栖菜主产区浙江省洞头县的12个羊栖菜养殖品系的重要形态特征进行了比较研究,并利用AFLP技术对一个典型养殖种群的遗传多样性进行了分析。结果显示,这12个品系在全长、全湿质量、侧枝长、侧枝湿质量、侧枝密度等方面存在显著或极显著差异(P<0.05或P<0.01)。8组AFLP引物在这个典型养殖种群中扩增出198个片段,其中多态性片段为166个,多态性位点比例为83.8%。根据个体间的遗传距离,以UPGMA法构建了个体间的系统树图,27个羊栖菜个体聚为一枝,作为对照的铜藻为另一枝。本研究从形态和DNA分子水平说明了浙江洞头羊栖菜养殖种群具有高度遗传多样性。