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蔷薇科具有独特的成对外轮雄蕊、多数的雄蕊轮、高度的雄蕊群形态多样性和发育多样性.如何解释蔷薇科的雄蕊群发育是长期研究而未解决的问题,此前, Linfenhofer和Weber提出了一种蔷薇科特殊的雄蕊群发生模式——绣线菊模式,但该模式能否作为蔷薇科雄蕊发生的一般模式还存在极大的争议,且蔷薇科内部分属的特殊雄蕊群结构如何发生仍然不清楚.白鹃梅属具有蔷薇科中少见的束状雄蕊,而此前的研究并未解释这种束状雄蕊的成因.本研究以白鹃梅和齿叶白鹃梅为研究对象,利用扫描电子显微镜详细研究了从花原基到成熟花的整个发育过程.结果显示,对萼雄蕊的消失和对萼位置被丝托的扩张共同促成了雄蕊束的形成.同时,白鹃梅属的雄蕊发育模式还修正了绣线菊模式的雄蕊群排列,并验证了绣线菊模式的重复叠加作为蔷薇科雄蕊发育基础的可能性. 相似文献
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多毛白鹃梅 新变种 Exochorda serratifolia S. Moore var. polytricha C. S. Zhu, var. nov. A var. serratifolia ramulis hornotinis, rhachidibus inflorescentiarum, pedicellis, petioliset foliorum laminis subtus dense crispe albo-pubescentibus differt. 相似文献
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医院后勤设备是保障医、教、研活动正常运转的基本条件,也是构成医院基础质量的基本要素。它不仅具有为医疗活动提供条件保障的一面,而且还具有为病人和医院职工提供生活服务的一面;不仅具有生产性的一面,而且还具有消耗性的一面。因此搞好医院后勤设备的管理,推行低碳经济建设,发挥后勤设备的功能和作用,使之更好地为医、教、研服务,为病人和医院职工服务,是医院管理的一个重要内容。 相似文献
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以陕西红香米、绿香米、紫糯、茉莉香米、黑帅、黑宝为实验材料,采用SDS-PAGE方法在pH为8.9,电流为15mA条件下,对其种子的谷蛋白进行了电泳分析,寻找其特征及其之间的差异。结果表明绿香米、黑帅都具有9条特征谱带;茉莉香米具有7条特征谱带;紫糯具有6条特征谱带;黑宝具有5条特征谱带;红香米具有4条特征谱带。分子量较高、蛋白谱带较多的品系为绿香米和黑帅(6~5条);分子量较高、蛋白谱带较少的品系为茉莉香米(2条)。 相似文献
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<正>中药产业在中医药事业发展中具有基础性地位,中药产业的高质量发展,对于推动中医药走向世界、健康中国建设,以及实现中华民族伟大复兴的中国梦,具有不可或缺的作用。经过几十年的快速发展,我国中药产业已基本形成以科技创新为动力、中药农业为基础、中药工业为主体、中药装备工业为支撑、中药商业为枢纽的新型产业体系。近年来,我国中药产业发展模式逐渐从粗放型向质量效益型转变,产业技术标准化和规范化水平显著提高,涌现出了一批具有市场竞争力的优势企业和产品。在我国经济社会发展中,中药产业成为具有独特价值和广阔市场前景的战略性产业。 相似文献
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睾酮丛毛单胞菌Comamonas testosteroni JA1是一株具有氰基吡啶羟基化酶活性的菌株,研究表明它还具有很高的烟酸羟基化酶的活性,是未报道过的具有烟酸羟基化酶活性的新菌种。该菌最适生长和产酶的碳源为1%葡萄糖、氮源为1%蛋白胨、诱导物为1%烟酸,此外,它的发酵条件优越,在温度25~37℃、初始pH6.5~7.0、装液量(100mL锥形瓶)10mL~40mL范围内,产酶能力均保持很高水平,很具有工业化生产应用的前景。 相似文献
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菠菜种子胰蛋白酶抑制剂的分离纯化与部分性质研究 总被引:3,自引:0,他引:3
以菠菜种子为材料,经脱脂、酸性溶液抽提、热变性、硫酸铵分部沉淀得到胰蛋白酶抑制剂粗提物。再经离子交换、亲和层析和凝胶过滤,分离得到胰蛋白酶抑制剂SOTI,纯化倍数为57.22。SDS-PAGE测定其分子量约为22kD,等电聚焦测定其等电点为4.02。SOTI具有较高的热稳定性,在100℃处理后仍然具有一定的抑制活性。 相似文献
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运用扫描电子显微镜法(SEM)对木通科(Lardizabalaceae)4属植物茎的次生木质部导管分子进行观察,结果表明:(1)端壁均具有单穿孔板;(2)串果藤属的导管分子具有丰富的穿孔板类型,包括网状、梯状、单穿孔及过渡类型,穿孔具有网状、丝状、片状的纹孔膜残余;大血藤属和八月瓜属的导管分子具有相似的特征,端壁具有梯状、单穿孔及梯—单混合穿孔板;野木瓜属只具有单穿孔板;(3)侧壁上具有穿孔板,多为梯状或梯—网混合类型(除了野木瓜属);(4)野木瓜属的导管侧壁具有独特的螺旋状加厚。各属导管的不同特征为木通科的系统演化提供比较可靠的依据。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献