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Melø TM Larsen C White LR Aasly J Sjøbakk TE Flaten TP Sonnewald U Syversen T 《Biological trace element research》2003,96(1-3):1-8
The concentrations of manganese, copper, and zinc in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS)
and patients with no known neurological disease (control group) were measured. Manganese and copper levels were determined
by two different analytical methods: atomic absorption spectrometry (AAS) and high-resolution inductively coupled plasma-mass
spectrometry (HR-ICP-MS), whereas zinc levels were determined by HR-ICP-MS only. Manganese levels (mean±SEM) were significantly
decreased in the CSF of MS patients (1.07±0.13 μg/L, ICP-MS; 1.08±0.11 μg/L, AAS) compared to the levels in the control group
(1.78±0.26 μg/L, ICP-MS; 1.51±0.17 μg/L, AAS). Copper levels were significantly elevated in the CSF of MS patients (10.90±1.11
μg/L; ICP-MS, 11.53±0.83 μg/L, AAS) compared to the levels in the control group (8.67±0.49 μg/L, ICP-MS; 9.10±0.62 μg/L, AAS).
There were no significant differences between the CSF zinc levels of MS and control patients. The physiological basis for
the differences in manganese and copper concentrations between MS patients and controls is unknown, but could be related to
alterations in the manganese-containing enzyme glutamine synthetase and the copper-containing enzyme cytochrome oxidase. 相似文献
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钙、锌和六磷酸肌醇的含量是反映农作物营养价值的重要指标.以两年生盾叶薯蓣(Dioscorea zingiberensis C.H.Wright) 植株根状茎为材料,对其在不同生长时期的钙、锌以及六磷酸肌醇含量进行测定并对其相互关系进行了分析. 结果表明: 盾叶薯蓣根状茎中钙的平均含量为424.24 mg/100 g干重;锌的平均含量为12.73 mg/100 g干重;六磷酸肌醇的平均含量为4460.19 mg/100 g干重;六磷酸肌醇对钙和锌的吸收有影响.盾叶薯蓣根状茎的淀粉平均含量为32.84 g/100 g干重;最大还原力为0.931,最大自由基清除效应为22.83%,表明其有一定的抗氧化能力.这些结果表明盾叶薯蓣根状茎具有一定的营养价值和保健价值. 相似文献
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不同灵芝子实体及其粗多糖中微量元素及重金属含量分析* 总被引:1,自引:0,他引:1
利用电感耦合等离子发射光谱-质谱联用法(ICP-MS)、原子荧光法(AFS)和原子吸收法(AAS)对不同品种灵芝子实体中的生物必需微量元素、有毒的微量元素及重金属元素的含量进行了测定,并对其营养性和安全性进行了分析。与砷、镉、汞相比,在所有品种的灵芝中重金属铅的含量相对较高,但是在对全国各地收集的灵芝及其培养基分析,灵芝对铅没有生物富集的作用。另外,灵芝粗多糖中各种元素的含量均明显高于提取用的灵芝子实体,其中铅和砷含量高于国家标准,其安全性应该受到重视。 相似文献
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米根霉发酵液中乳酸含量的测定方法研究 总被引:2,自引:0,他引:2
目的:为了找到方便、准确、快捷的米根霉RL6041菌株发酵液中乳酸含量的检测方法。方法:同时采用EDTA定钙法、高效液相色谱(HPLC)法和生物传感仪法三种方法测定米根霉RL6041菌株发酵液中的乳酸含量。结果:米根霉RL6041菌株三批次发酵的测试结果的差异显著性分析表明,在同一发酵批次的乳酸含量测试中,EDTA定钙法与HPLC法、生物传感仪法有显著差异(p<0.05),而HPLC法与生物传感仪法无显著性差异(p>0.05)。EDTA定钙法平均误差7.50g/L;而HPLC法和生物传感仪测定法的平均误差分别为2.84g/L和2.39g/L。结论:EDTA定钙法简便快速,但重复性差;HPLC法准确、灵敏;生物传感仪测定法比较准确和方便。 相似文献
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黄伞菌丝蛋白质营养价值评价 总被引:3,自引:0,他引:3
本文测定了黄伞Pholiotaadiposa菌丝粗蛋白含量和氨基酸组成,采用国际上通用的营养价值评价方法,对其蛋白质的营养价值进行全面评价,并与营养价值较高的白灵侧耳Pleurotusnebrodensis、刺芹侧耳Pleurotuseryngii和金顶侧耳Pleurotrscitrinopileatus进行比较。分析结果表明,黄伞菌丝的必需氨基酸含量最高,占其氨基酸总量的43.9%,蛋白质的氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)、生物价(BV)、营养指数(NI)和氨基酸比值系数分(SRCAA)分别为92.0、71.3、88.5、84.8、40.4和78.8,六项指标均比参比食用菌高。结果说明黄伞菌丝具有很高的营养价值。 相似文献
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《生命世界》2005,(2)
家蚕在动物分类学上属于节肢动物门(Arthropoda)昆虫纲(Insecta)鳞翅目(Lepidoptera)大鳞翅亚目(Macroloepidoptera)蚕蛾科(Bombycidae)蚕蛾属(Bombyx)桑蚕(Bombyx mori) 家蚕在动物分类学上属于节肢动物门(Arthropoda)昆虫纲(Insecta)鳞翅目(Lepidoptera)大鳞翅亚目(Macrolepidoptera)蚕蛾科(Bombycidae)蚕蛾属(Bombyx)桑蚕(Bombyx mori)与家蚕关系最密切的是同属的野桑蚕.它是家蚕的祖先。另外,大蚕蛾科柞蚕属的柞蚕,天蚕以及蓖麻蚕属的蓖麻蚕都是野外能作茧取丝的蚕类。樟蚕(Eriogyna pyretorum)属大蚕蛾科,原产广东、广西一带,以樟叶、枫叶为食,它的丝被人们利用已有上千年的历史,大约在公元885年前后已有记载,其丝为纺织上等原料。古时用樟蚕丝经醋浸泡后拉丝作为弓弦,强度极大。现作为钓鱼线和医用缝合线出口。樗蚕(Philosamia cynthia)属大蚕蛾科其饲养历史不详。在山东省有小规模饲养饲料是乌桕和臭椿。在南方有篦麻蚕。柞蚕(Antheraea pernyi)属大蚕蛾科,原产山东莱州(掖县),是我国地位仅次于桑蚕的产丝昆虫,现盛产于辽宁、河南等省。柞蚕最早见于《尔雅》(公元前1200年)2700年前柞蚕丝已作为给皇帝的贡物.在汉代曾经由官方推广,经宋、元、明、清几代引种推广,分布到了全国很多省份。其主要饲料树种是各种栎属植物的叶子。 相似文献
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蓖麻蚕Phtlosamta cynthia ricim后部丝腺体在五龄后期主要合成一种蛋白质——丝心蛋白。在组成丝心蛋白的氨基酸成分中,丙氨酸和甘氨酸占了78%,其中内氨酸的含量比甘氨酸高(Kirimura等1962)。已经知道在五龄期,蓖麻蚕后部丝腺体tRNA含量与丝心蛋白的氨基酸成分之间存在着相关性(辜祥荣等,1981)。在生物体内,氨基酸必须与其相应的tRNA结合才能参与蛋白质的合成,而两者的结合反应是由其相应的氨基酰-tRNA合成酶所催化的。本文测定了五龄期蓖麻蚕后部丝腺体中甘氨酰-tRNA合成酶和丙氨酰-tRNA合成酶的活力,以及这两个酶的Km值,观察到在五龄期,这两个酶的活力是随着蛋白质合成的增加而升高的,而且并没有同功酶或酶的变构产生。 相似文献
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湖南烟区土壤交换性钙、镁含量及对烤烟品质的影响 总被引:28,自引:0,他引:28
分析了湖南烟区主要土壤类型交换性钙、镁元素含量状况及其对烟叶品质的影响,结果表明:(1)土壤交换性钙、镁含量在不同土壤类型间存在显著性差异,交换性钙含量平均为8.87cmol/kg,以红壤含量最高;交换性镁含量平均为1.16cmol/kg,以黄棕壤含量最高;交换性钙镁比值大小依次为:红壤(11.74)>水稻土(10.25)>黄壤(6.84)>黄棕壤(6.14),在烟叶实际生产中,应重视镁肥在红壤和水稻土中的施用;(2)烟叶钙含量偏高(21.93g/kg±4.37g/kg),烟叶镁含量偏低(2.52g/kg±1.26g/kg),两者均存在广泛的变异性;(3)整体来看,烟叶钙含量随土壤中交换性钙含量的升高和镁含量的降低而显著升高;烟叶镁含量随土壤交换性镁含量的升高而升高,与土壤交换性钙含量的相关性不显著;(4)典型相关分析表明,土壤中交换性镁含量的降低可能引起烟叶钾含量的提高,从而使得烟叶钾素和镁素含量达到较好的平衡;(5)土壤交换性钙、镁含量与烟叶其它化学成分指标的相关分析表明,土壤交换性钙有利于烟株对硼和氯素的吸收,对氮、锌和锰素的吸收则有显著的抑制作用;而土壤交换性镁有利于烟叶总糖、硼素和锰素的积累,对氮、磷、铁和锌素的吸收具有显著的抑制作用。 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