1000 resultados para 49-411


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[ES] El propósito de este trabajo es el de mostrar cómo Livio elabora el episodio de la violación de Lucrecia de tal manera que se conecta con los restantes episodios del reinado de Tarquinio el Soberbio, formando una unidad tan estrecha y bien dispuesta que éste se convierte en el punto culminante de un proceso que comienza con el inicio del reinado del último monarca romano. Livio no se limita a seleccionar y disponer en una simple secuencia temporal los hechos que la tradición atribuía al segundo Tarquinio, sino que los elabora y ordena con vistas a conseguir un relato efectivo desde la perspectiva literaria y narrativa y, como consecuencia de ello, convincente desde el punto de vista moral, una de sus principales preocupaciones.

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Age and growth estimates for the blue shark (Prionace glauca) were derived from 411 vertebral centra and 43 tag-recaptured blue sharks collected in the North Atlantic, ranging in length from 49 to 312 cm fork length (FL). The vertebrae of two oxytetracycline-injected recaptured blue sharks support an annual spring deposition of growth bands in the vertebrae in sharks up to 192 cm FL. Males and females were aged to 16 and 15 years, respectively, and full maturity is attained by 5 years of age in both sexes. Both sexes grew similarly to age seven, when growth rates decreased in males and remained constant in females. Growth rates from tag-recaptured individuals agreed with those derived from vertebral annuli for smaller sharks but appeared overestimated for larger sharks. Von Bertalanffy growth parameters derived from vertebral length-at-age data are L∞ = 282 cm FL, K = 0.18, and t0 = –1.35 for males, and L∞ = 310 cm FL, K = 0.13, and t0 = −1.77 for females. The species grows faster and has a shorter life span than previously reported for these waters.

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对两种不同基因型小麦京411(北京地区高产小麦品种)和小偃54(在生产上已应用二十年的优良品种)幼苗及旗叶光抑制特性进行了比较研究,着重探讨了它们抗光氧化的差异及其机理,主要结果如下: 1. 强光条件下,同京411相比小偃54能保持较高的光合色素含量和放氧速率。其DCPIP光还原活性也较高。 2. 光谱特性分析表明,强光胁迫下小偃54在红区及蓝区的特征性吸收峰及F683荧光发射峰下降的幅度明显小于京411相应峰位的下降。 3. 色素蛋白复合物分析表明,强光条件下,京411色素蛋白复合物中LHCII聚合体大量的解聚,而小偃54在强光条件下仍能保持较高比例的LHCII聚合体。这可能在一定的程度上有利于小偃54在强光下维持较强的激发能耗散的能力。 4. 多肽SDS-PAGE分析表明,强光对不同基因型小麦中同PSII光抑制敏感性有关的两个外周蛋白23kD和17kD的影响不同。光抑制明显地降低了京411的23kD和17kD的含量,而对于小偃54中这两个外周蛋白23kD和17kD的影响不大。强光条件下小偃54旗叶PSII颗粒中捕光色素蛋白27kD含量提高,而京411捕光色素蛋白27kD含量明显的下降。 5. 上述结果表明,西北地区的优良小麦品种小偃54同北京地区的高产品种京411相比更耐强光的胁迫,其抗光氧化的能力较强。 6. 进一步分析表明,同京411相比,小偃54抗光氧化的主要原因是其不仅含有较大的叶黄素循环的色素库,而且在强光下能维持高的VDE酶活性及高水平的叶黄素循环的脱环化水平。 7. 叶黄素循环色素在两个小麦品种类囊体膜色素蛋白复合体中的分布存在差异,抗光氧化的小偃54大部分的VAZ分布在PSII上,其中绝大部分集中在LHCII聚合体上。LHCII上VAZ的集中分布可能有利于在强光下对过多光能的耗散,减少过多激发能对PSII的损伤。 8. 类囊体膜流动性分析表明,叶黄素循环参与了对类囊体膜流动性的调整,对维持强光下抗光氧化品种小偃54的类囊体膜相对稳定起重要作用。 9. 依赖于叶黄素循环的热耗散是抗光氧化品种小偃54的一个主要的光保护途径。

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Group IIA phospholipase A(2) (PLA(2)) are major components in Viperidae/Crotalidae venom. In the present study, a novel PLA(2) named promutoxin with Arg at the site 49 has been purified from the venom of Protobothrops muerosquamatus by chromatography. It

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于2010-11-23批量导入

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采用测量反射谱方法确定了低压金属有机化合物气相外延生长的GaAs衬底匹配(Al_xGa_(1-x))_(0.51)In_(0.49)P外延材料的折射率。实验中测量的反射谱波长范围为05-2.5μm。在拟合实验数据过程中采用了单振子模型。折射率数据用于分析应变量子阱GaInP/AlGaInP可见光激光二极管波导,计算出的器件远场图与实验数据吻合很好。