Results 31 to 40 of about 30,612 (170)
Zhongguo shiyan zhenduanxue, 2011 心血管系统合成和分泌多种小分子的生物活性物质,如血管活性多肽、生物活性氨基酸、细胞因子生长因子和一氧化碳、硫化氢等气体信号分子。这些生物活性分子具有分子量小、种类繁多 ...
张婧, 冷吉燕
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A Protocol of Separating and Measuring Different Species of Dissolved Metals (Labile and Hydrophobic Organic Fractions) in Seawater and Its Applications in the Jiulong River Estuary and Taiwan Shallow [PDF]
, 2016 作为生源要素，海洋中许多痕量金属都构成了生物酶的活性中心，然而金属含量过高也会造成水环境的污染。特别是近年来随着环境污染的日益加剧，我国近岸水体中金属的含量也不断上升，而无论金属的污染甚至生物可利用性则都与金属存在的形态密切相关。本论文利用Chelex100、C-18固相萃取离子交换法成功地分离出不同形态的金属，包括生物活性态（Chelex100树脂吸附部分）、非活性疏水有机态（C-18树脂吸附部分）、剩余形态（总溶解态-生物活性态-非活性疏水有机态 ...
张雪莲
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Taxonomic and functional diversity of urban bees of the world
Conservation Biology, EarlyView.Abstract Bees play a pivotal role in terrestrial environments. Urbanization can affect these organisms and the ecosystem services they provide. However, knowledge of the global diversity of urban bees is limited. Thus, we summarized data on urban bee species identities and occurrences; compared distributions of all bees with those found in urban ...
João C. F. Cardoso +10 more
wiley +1 more source
Shuitu Baochi Xuebao, 2006 大田试验研究了保护性耕作对土壤微生物量、活跃微生物量、土壤呼吸、呼吸商、土壤酶的影响。结果表明，秸秆还田能够显著提高土壤微生物量碳和活跃微生物量，深松耕还田能显著提高土壤活跃微生物量。随耕作作业之后时间的推迟，活跃生物量减小。秸秆还田初期（小麦越冬期）能显著提高土壤呼吸作用，提高99．7％；后期（小麦播种期）能显著降低土壤呼吸，降低16．6％。随耕作作业之后时间的推迟，秸秆还田和保护性耕作都会减少农田向大气中CO2的排放，减少土壤碳库的亏损。深松耕还田显著提高土壤脲酶、蔗糖酶活性 ...
王芸 +7 more
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Selective Isolation, Identification and Biological Activity Investigation of Rare Actinomycetes from Rhizosphere Soil [PDF]
, 2016 天然产物是新药制备的重要原料，绝大多数来源于微生物的天然产物都分离自放线菌，尤其是链霉菌。链霉菌是放线菌的重要组成成员，能合成结构类型丰富、生物活性多样的次级代谢产物，可用于创制抗生素、抗肿瘤药物、免疫抑制药物、抗虫药物等，在医疗、农业、食品等领域具有重要的应用价值。然而，随着对链霉菌持续的开发利用，目前从链霉菌中发现新型、高活性的次级代谢产物的几率在不断下降，来源于链霉菌的新药研发速度明显放缓。为了解决链霉菌活性次级代谢产物资源日趋枯竭的问题 ...
施金迪
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Using customs data to understand overlooked trade in non‐CITES birds between Africa and Asia
Conservation Biology, EarlyView.Abstract The international trade in live birds poses risks to animals, people, and biodiversity. To effectively mitigate these risks, decision‐makers require information on the volume, dynamics, and direction of trade. Despite Africa once being the largest exporter of birds by region, very little data exist on recent trade in live birds not listed on ...
Alisa Davies +4 more
wiley +1 more source
Shuitu Baochi Xuebao, 2011 通过田间试验,研究不同尿素施用量对道地药材滁菊土壤微生物数量、土壤酶活性和土壤微生物量碳、氮和产量的影响。结果表明,随着尿素施用量的提高,土壤细菌、真菌、放线菌和土壤过氧化氢酶、蛋白酶、脲酶呈先增加后降低的变化趋势,以N1(225kg N/hm2)或N2(450kg N/hm2)处理的酶活性较高,N3(675kg N/hm2)处理的酶活性略有降低;磷酸酶活性则呈上升趋势,以N3(675kg N/hm2)处理的脲酶活性最大。就土壤微生物量而言,土壤微生物C和土壤微生物N随施氮量的增加呈先增加后降低的趋势 ...
肖新 +6 more
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Structural and Functional Analysis of Paralytic Neurotoxins from Terrestrial Mammals [PDF]
, 2013 科学研究費助成事業(科学研究費補助金)研究成果報告書：若手研究（Ａ）2009-2012課題番号 ...
Kita Masaki, 北 将樹
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Cost of parasite exposure depends on host ontogeny 寄生接觸的代價依賴於宿主發育階段
Ecological Entomology, EarlyView.The cost of parasite exposure varies across host developmental stages, demonstrating that ontogeny influences the expression of non‐consumptive effects (NCEs). Mite exposure resulted in consumptive effects in fly eggs and NCEs in early‐stage pupae; mite longevity was comparable when provisioned with pupae or water but increased when provisioned with ...
Lisa R. MacLeod +2 more
wiley +1 more source
Shuitu Baochi Xuebao, 2008 通过分析退化生态系统中主要植被恢复类型对土壤微生物群落活性的影响,探讨敏感和可靠的微生物群落活性响应指标,揭示适合当地生态条件的植被恢复类型。结果表明,沙米荒地、白沙蒿、柠条、沙冬青和人工乔木林地土壤微生物量C,N,P和微生物商、蔗糖酶、脲酶、过氧化氢酶、碱性磷酸酶均表现出显著差异 ...
毕江涛 +4 more
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