63 resultados para 883


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目的 :观察自行合成的聚己内脂 (PCL)、聚丙交酯 (PLA)及其不同比例的共聚物己内酯 /丙交酯共聚物a(PCLA2 /1)、己内酯 /丙交酯共聚物b(PCLA1/2 )在体外模拟的不同生物环境中的降解性质 ,探讨环境及材料结构与生物降解性质的关系 ,为在不同生物环境下选用适宜的生物降解材料提供实验依据。方法 :4种聚合物在血浆、胆汁、胰腺悬液中降解 1~ 7d ,观察材料的物理性状改变、测量质量损失和分子量变化。结果 :在不同生物降解液中 :PCL降解不明显、PLA降解最明显 ,PCLA2 /1和PCLA1/2在不同环境中降解规律不同。结论 :用不同比例单体共聚的方法获得了不同结构的生物材料 ,它们在不同环境中降解性质不同。

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The complex [Nd(L)(CH3CN)(CF3SO3)3] has been synthesized. Where L = 1-methyl-1, 4, 7, 10-tetraazacycldodecane. The crystal structure of the complex has been determined by a four-circle X-ray diffractometer to a final deviation factor B value of 0.0370 and R(w) value of 0.0385 respectively. The crystal is triclinic system, space group P1BAR with a = 0.8738(2), b = 1.2870(3), c = 1.2900(3) nm, alpha = 85.63(2), beta = 87.25(2), gamma = 78.30(2)-degrees, V = 1.41571 (60) nm3, Z = 2, D(c) = 1.92 g/cm3. The neodymium ion is eight-coordinated to forming a distorted square antiprism.

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本文报道了三价钕与氮杂大环(简称L)配合物的合成和晶体结构.配合物组成为[Nd(L)-(CH_3CN)(CF_3SO_3)_3],晶体属于三斜晶系,空间群为PI,晶胞参数α=0.8738(2),b=1.2870(3),c=1.2900(3)nm;α=85.63(2),α=87.25(2),γ=78.30(2)°;最终偏差因子R=0.0370,R_w00385.配合物中钕为8配位,其配位多面体为扭曲的四方反棱柱体.

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The reaction of GdCl3 with 1 equiv of NaC5Me5 generates a neutral complex C5Me5GdCl2(THF)3 and a novel complex {Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-2-Cl)3(mu-3-Cl)2}2.6THF whixh recrystallizes from THF in triclinic, the space group P1BAR with unit cell dimentions of a 12.183(4), b 13.638(6), c 17.883(7) angstrom, alpha-110.38(3), beta-94.04(3), gamma-99.44(3)-degrees, V 2721.20 angstrom-3 and D(calc) 1.43 g cm-3 for Z = 1. Least-squares refinement of 2170 observed reflections led to a final R value of 0.047. The title complex consists of two Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-3-Cl)3(mu-3-Cl)2 units bridged together via two mu-2-THF to Na coordination. Each Gd ion is surrounded by one C5Me5 ligand, two mu-3-Cl, two mu-2-Cl and one THF in a distorted octahedral arrangement with average Gd-C(ring) 2.686(33), Gd-mu-2-Cl 2.724(7), Gd-mu-3-Cl 2.832(8) and Gd-O 2.407(11) angstrom. The sodium ion coordinates to two bridging THF, two mu-2-Cl and two mu-3-Cl to form a distorted octahedron with average Na-mu-2-O, Na-mu-2-Cl and Na-mu-3-Cl of 2.411(21), 2.807(15) and 2.845(12) angstrom, respectively.

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Three samples of β-carboxyethyl-germanium sesquioxide (Ge-132) have been prepared with different methods. Their IR, Raman, XPS, TG-DTA and FAB-MS spectra are quite different and indicate that they have different degree of polymerization and molecule structures. In the aqeous solution, all of them interaot strongly with fructose, but not with polypeptides such as GSH and GSSG. This faot may be important in understanding the bioactivity of Ge-132.

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三种不同制备方法的β-羧乙基锗倍半氧化物(Ge-132),其红外、拉曼光谱、光电子能谱以及热分析行为表现一定差异。这种差异主要因制备方法不同,获得样品中羧基间氢键作用以及Ge—O环尺度和键角不同引起的。它们在水溶液中均水解为三羟锗基丙酸,~1H NMR谱上观察到与果糖有较强作用,与谷胱甘肽作用不明显,为了解Ge-132的生物作用机理提供了重要信息。

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The mass spectra of twelve phosphorothionates and phosphorodithionates have beenstudied by using low resolution EI, CI and high resolution as well as metastabletechnique. The fragmentation behaviour of the compounds and structure of characterit

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本文应用低分辨电子轰击源质谱,化学电离质谱,高分辨精确质量测量,亚稳分析和不同取代基衍生物方法,研究了十二种硫逐磷酸酯和二硫代磷酸酯的质谱。根据所得数据,推断并讨论了这些化合物的断裂机理及特征离子的结构。

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Rel/NF kappa B is a family of transcription factors. In the present study, a Rel/NF kappa B family member, Dorsal homolog (FcDorsal) was cloned from the Chinese shrimp Fenneropenaeus chinensis. The full length cDNA of FcDorsal consists of 1627 bp, revealed a 1071 bp open reading frame encoding 357 aa. The predicted molecular weight (MW)of the deduced amino acid sequence of FcDorsal was 39.78 kDa, and its theoretical pl was 8.85. Amino acid sequence analysis showed that FcDorsal contains a Rel homolog domain (RHD) and an IPT/TIG (Ig-like, plexins and transcriptions factors) domain. The signature sequence of dorsal protein existed in the deduced amino acid sequence. Spatial expression profiles showed that FcDorsal had the highest expression level in the hemocytes and lymphoid organ (Oka). The expression profiles in the hemocytes and lymphoid organ were apparently modulated when shrimp were stimulated by bacteria or WSSV. Both Gram-positive (G(+)) bacteria (Micrococcus lysodeikticus) and Gram-negative (G(-)) bacteria (Vibrio anguillarium) injection to shrimp caused the up-regulation of FcDorsal at the transcription level. DsRNA approach was used to study the function of FcDorsal and the data showed that FcDorsal was related to the transcription of Penaeidin 5 in shrimp. The present data provide clues that FcDorsal might play potential important roles in the innate immunity of shrimp. Through comparison of the expression profiles between FcDorsal and another identified Rel/NF kappa B member (FcRelish) in shrimp responsive to WSSV challenge, we speculate that FcDorsal and FcRelish might play different roles in shrimp immunity. (C) 2010 Elsevier Ltd. All rights reserved.

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We constructed genetic linkage maps for the bay scallop Argopecten irradians using AFLP and microsatellite markers and conducted composite interval mapping (CIM) of body-size-related traits. Three hundred seventeen AFLP and 10 microsatellite markers were used for map construction. The female parent map contained 120 markers in 15 linkage groups, spanning 479.6 cM with an average interval of 7.0 cM. The male parent map had 190 markers in 17 linkage groups, covering 883.8 cM at 7.2 cM per marker. The observed coverage was 70.4% for the female and 81.1% for the male map. Markers that were distorted toward the same direction were closely linked to each other on the genetic maps, suggesting the presence of genes important for survival. Six size-related traits, shell length, shell height, shell width, total weight, soft tissue weight, and shell weight, were measured for QTL mapping. The size data were significantly correlated with each other. We subjected the data, log transformed firstly, to a principle component analysis and use the first principle component for QTL mapping. CIM analysis revealed one significant QTL (LOD=2.69, 1000 permutation, P<0.05) in linkage group 3 on the female parent map. The mapping of size-related QTL in this study raises the possibility of improving the growth of bay scallops through marker-assisted selection. (c) 2007 Published by Elsevier B.V.

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对海北高寒草甸矮嵩草种群生长季光合作用及群落生长参数的测定表明,矮嵩草种群最大光合速率及表观量子效率的季节变化为6月>7月>8月>9月;群落地上净生物量及叶面积指数在生长季内呈上升趋势,地上净生物量增长速率和叶面积指数增长速率为6月>7月>8月>9月,其中9月份均为负增长。矮嵩草种群季节内的光合作用能力与群落的生产力密切相关。

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雪鸡坪斑岩铜矿位于西南三江构造火成岩带义敦岛孤带,其成矿斑岩为印支期石英闪长玢岩和石英二长宽岩。研究对该矿区安山岩、矿化斑岩和矿石矿物系统进行S,Pb同位素分析结果表明:金属硫化物的δ34S值为-3.1‰~+0.7‰,平均值为-1.1‰,与矿化斑岩的硫同位素组成(-1.4‰和-1.5‰)一致,均落入幔源硫范围,表明硫主要来自岩浆;δ34S黄铁矿(-1.8‰~+0.7‰,平均0.5‰)〉δ34S黄铜矿(-2.2‰~0.0‰,平均-1.2‰)〉δ34S方铅矿(-3.1‰~1.3‰,平均-2.4‰),硫同位素分馏基本达到平衡。矿石矿物(208Pb/204Pb=37.917~38.230,平均值38.075;207Pb/204Pb-15.528~15.614,平均值15.571;206Pb/204Pb=17.929~18.082,平均值17.981)与矿化斑岩(208Pb/204Pb=37.832、37.883,207Pb/204Pb=15.529、15.538,206Pb/204Pb=17.906、17.910)以及安山岩(208Pb/204Pb=37.816~37.884,207Pb/204Pb-15.549~15.562,206Pb/204Pb=17.845~17.919)的初始铅组成基本一致,变化范围较小,表明三者具有相同的来源;在铅构造模式图上,所有样品铅同位素均位于造山带演化线上或附近,在铅同位素源区判别图中,均落入造山带和下地壳区域,这表明Pb主要来源于壳幔混合。雪鸡坪铜矿S,Pb同位素组成共同指示成矿物质主要来自于深部岩浆,这种岩浆可能主要起源于俯冲洋壳板片的部分熔融并受到少量地壳物质的混染。

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云南白马寨镍矿区煌斑岩全部为云煌岩.两个样品的^40Ar/^39Ar定年结果分别为32.46±0.62Ma和32.01±0.60Ma,表明矿区煌斑岩为哀牢山断裂带新生代早期高钾岩浆活动的产物.在化学组成上,矿区煌斑岩具有高M值[100×Mg/(Mg+Fe^2+)](67.42~86.35)、高ALK(K2O+Na2O为7.01%~9.81%)、富钾(K2O/Na2O为1.66~2.64)、富大离子亲石元素(如Sr、Rb、Ba等)和LREE、明显的Ta、Nb、Ti负异常的特征.Sr-Nd同位素具有高(^87Sr/^86Sr)0比值(0.70625~0.70912)和低εNd(-5.22~-3.68)的特征,位于EM1和EM2地幔端元之间,有更靠近EM2的趋势.元素和同位素地球化学特征表明矿区煌斑岩的源区为交代富集地幔,进一步判别表明源岩处于尖晶石相方辉橄榄岩和石榴石相二辉橄榄岩的混合线上,以尖晶石相方辉橄榄岩为主.源区交代富集的矿物既有金云母,也有角闪石.岩浆演化过程中经历了橄榄石+斜长石±磷灰石±铁钛氧化物的结晶分异.岩浆形成于大陆弧的构造背景,俯冲的陆壳和古特提斯洋壳对富集的源区均有贡献.白马寨镍矿区煌斑岩和哀牢山断裂带新生代早期其它高钾岩浆岩具有相近的年代、一致的地球化学特征,表明它们具有相似的源区,受控于相同的构造背景.

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介绍了自组织、自组织临界态理论和耗散结构理论的概念及其近年来在地学特别是地球化学研究领域的应用情况