736 resultados para 907
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The strong chelating ability of mercaptoacetic acid for certain metal ions is exploited for a new; kind of voltammetric sensor. Specifically, a glassy carbon electrode (GCE) surface was covalently covered br; mercaptoacetic acid. The preparation of mercap
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Rare earth complexes of m-nitrobenzoic acid (LnL3.2H2O, Ln = La-Lu and Y, except Pm, HL = m-nitrobenzoic acid) were synthesized and characterized by elemental analysis, chemical analysis, IR spectroscopy and X-ray diffraction analysis. The dehydration beh
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选择不同电离电位的基体元素K、Na、La、Y和Mg,比较研究了它们对分析元素谱线强度的影响,其影响程度与谱线激发电位及基体元素电离电位有定量的相关关系。碱金属基体(K、Na)和非碱金属基体(La、Y和Mg)对分析元素检出限、背景强度及其相对标准偏差的影响显著不同,后者的记忆效应也大于前者。La的电离电位与Na相差不大。但其基体效应与Y相似,表明墓体效应与基体元素的化学性质有关。
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本文对藻蓝蛋白复合物保护化学性肝损伤的功效学进行了研究。以Wistar大鼠建立酒精性肝损伤模型,将藻蓝蛋白复合物分为高、中、低三个剂量组,以联苯双酯作为阳性对照组,灌胃给药42d,分别测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、血清丙二醛(MDA)、谷胱甘肽(GSH)、肝匀浆丙二醛(MDA)和谷胱甘肽(GSH)的含量,并对肝脏切片进行病理检查。结果表明:藻蓝蛋白复合物对血清ALT、AST具有显著的抑制作用,显著拮抗肝脏MDA的升高,显著提高肝脏GSH-Px含量。出现肝细胞浊肿、脂肪变性、点状坏死的大鼠数目极少。从而表明藻蓝蛋白复合物具有显著的保护酒精性肝损伤的功效。
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选用全糯小麦品种‘糯麦1号’与青海主要栽培品种‘阿勃’杂交,综合利用改良碘染色法、SDS-PAGE法和Waxy基因的分子标记等,对杂交后代进行了鉴定筛选。最终从F2代鉴定出了5粒全糯种子,从F_代鉴定出8株Wx-B1亚基缺失的植株。对全糯株系F_3代的农艺性状进行评价,5个全糯株系的综合农艺性状都优于‘糯麦1号’,与‘阿勃’较接近。测定全糯株系和Wx-B1亚基缺失植株F_4代种子的直链淀粉含量,5个全糯株系F_4代种子的直链淀粉含量接近于0,8个Wx-B1亚基缺失植株F_4代种子的直链淀粉含量在总 体上比‘阿勃’的直链淀粉含量低。研究表明,采用综合标记辅助选择可快速而准确地获得适合在青海栽培的全糯和部分糯性小麦。
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生物多样性与生态系统功能的关系及其机制是生态学领域的重大科学问题.人们越来越关注环境因子对多样性-生产力关系的影响.植物群落组成、物种丰富度、物种特征、生物量的分布结构和植物枯枝落叶对高寒草甸物种多样性和生产力有着重要的影响.因此,我们利用2001~2004年中国科学院海北生态系统定位站高寒草甸群落的实测资料,研究了不同环境梯度(土壤含水量和营养)下,植物群落生物量,物种丰富度及组成的变化.结果表明,植物群落物种组成的不同反应在生物量的分布上,以藏嵩草为优势种的藏嵩草沼泽化草甸群落总生物量(地上、地下)最高(13196.96±719.69g/m~2),次之是以杂类草和莎草科为主的小嵩草草甸(2869.58±147.52g/m~2),以禾本科和杂类草为主的矮嵩草草甸最低(2153.08±141.95g/m~2).藏嵩草沼泽化草甸中,草本植物枯枝落叶显著高于小嵩草、矮嵩草草甸,土壤含水量对草本植物枯枝落叶有较大的影响.不同类型草甸群落中,地上生物量与土壤有机质、全氮和群落盖度之间均呈显著正相关(P〈0.05);藏嵩草沼泽化草甸中,总生物量与物种丰富度呈负相关(rs=-0.907,P〈0.05)、地下生物量与土壤含水量呈正相关(rs=-0.900,P〈0.05);而在小嵩草和矮嵩草草甸中它们之间均没有达到显著水平,说明不同类型高寒草甸群落生产力除受物种多样性、功能群内物种密度和均匀度的影响,同时也受物种本身特征和外部环境资源的影响.不同类型草甸群落生物量的分布与土壤含水量和土壤养分的变化相一致.
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珠毛蟹甲草 ( Parasenecio roborowskii)是菊科千里光族中款冬亚族蟹甲草属的一种植物 ,在藏药上全草入药 ,有治疗哮喘等疾病之功效。本文首次观察了珠毛蟹甲草的大小孢子发生、雌雄配子体的发育 ,旨在为开发与利用该种植物提供有性生殖过程方面的基础资料。
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在西昆仑北缘早前寒武纪变质地层中,笔者等识别出大量不同时代的片麻状花岗岩,其中包括新元古代片麻状花岗岩。获得最新的新元古代片麻状花岗岩的单颗粒锗石SHRIMP年龄为815±57Ma,片麻状花岗岩的岩石学特征反映它们形成于裂解构造背景,结合对区域上新元古代地层及中元古代末期构造事件的研究,笔者认为新元古代片麻状花岗岩反映了古塔里木板块作为Rodinia超大陆一员发生裂解的时间,这对研究古塔里木板块在Rodinia超大陆中的位置及中国Rodinia超大陆裂解的研究提供了重要的地质依据。
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Autor w pracy stawia tezę, że „francusko-niemiecki motor” odegrał pozytywną rolę w procesie integracji europejskiej w XX w. Dzięki bliskiej współpracy francusko-niemieckiej możliwa była realizacja unii walutowo-gospodarczej, Wspólna Polityka Zagraniczna i Bezpieczeństwa oraz stworzenie w UE „obszaru wolności, bezpieczeństwa i sprawiedliwości”. W XXI w. trudna sytuacja gospodarcza Francji i napięcia społeczne spowodowały spadek jej znaczenia w Unii Europejskiej. Kryzys finansowy strefy euro oraz problem uchodźców wykreowały Niemcy na samotnego lidera w Unii Europejskiej. Jednakże współpraca francusko-niemiecka nie załamała się, gdyż oba państwa wzajemnie się potrzebują i zapewniają równowagę w Europie. Zdaniem wielu ekspertów, ze względu na ogólne nastroje w Europie, w Berlinie i Paryżu brakuje nowych idei ukazujących perspektywy rozwojowe Unii Europejskiej na najbliższe lata.
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117 hojas: fotografías.
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The guidance was commissioned from Dr Amina Memon and Lynn Hulse at Aberdeen University. Their work was overseen by a steering group with representatives from the Scottish Executive Justice Department, the Crown Office and Procurator Fiscal Service, NCH Scotland, the Association of Chief Police Officers in Scotland, the Association of Directors of Social Work, the Law Society for Scotland, the Scottish Association of Community Child Health and the Scottish Children’s Reporter Administration. A full list of those involved is given in the Appendix C. pt. 1. Guidance on interviewing child witnesses in Scotland -- pt. 2. Guidance on the questioning of children in court -- pt. 3. Lord Justice-General's memorandum on child witnesses: appendix to Guidance on the questioning of children in court -- pt. 4. Guidance on child witness court familiarisation visits -- pt. 5. Information about child, young and vulnerable adult witnesses to inform decision-making in the legal process: good practice guide -- pt. 6. Code of practice to facilitate the provision of therapeutic support to child witnesses in court proceedings -- pt. 7. Guidance on the conduct of identity parades with child witnesses.
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The aim of the current study was to evaluate the impact of chitosan derivatives, namely N-octyl-chitosan and N-octyl-O-sulfate chitosan, incorporated in calcium phosphate implants to the release profiles of model drugs. The rate and extent of calcein (on M.W. 650 Da) ED, and FITC-dextran (M.W. 40 kDa) on in vitro release were monitored by fluorescence spectroscopy. Results show that calcein release is affected by the type of chitosan derivative used. A higher percentage of model drug was released when the hydrophilic polymer N-octyl-sulfated chitosan was present in the tablets compared with the tablets containing the hydrophobic polymer N-octyl-chitosan. The release profiles of calcein or FD from tablets containing N-octyl-O-sulfate revealed a complete release for FD after 120 h compared with calcein where 20% of the drug was released over the same time period. These results suggest that the difference in the release profiles observed from the implants is dependent on the molecular weight of the model drugs. These data indicate the potential of chitosan derivatives in controlling the release profile of active compounds from calcium phosphate implants. (C) 2009 Elsevier Ltd. All rights reserved.