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60只ICR小鼠随机等分成正常对照组、模型组、寿眉组、白牡丹组、白毫银针组和表没食子儿茶素没食子酸酯（EGCG）组。通过烟熏法建立小鼠慢性阻塞性肺病（Chronic obstructive pulmonary,COPD）模型,3个等级的白茶水提物和EGCG通过灌胃给予药物,5周后处死,收集血浆、支气管肺泡灌洗液、肺组织和肝组织,测定肺组织病理学变化和各样品的生化指标,研究白茶对小鼠COPD的改善作用及机制。结果显示：（1）模型组肺组织出现大量炎性浸润与杯状细胞化生等病理损伤,白茶提取物和EGCG处理均能明显改善肺组织病理性损伤,白毫银针效果最佳;（2）模型组出现明显的氧化应激和炎症反应,丙二醛（MDA）、白介素-6（IL-6）与肿瘤坏死因子-α（TNF-α）水平显著升高,超氧化物歧化酶（SOD）活性显著下降,白茶提取物和EGCG处理均能显著降低MDA、IL-6与TNF-α水平并上调SOD活性;（3）模型组血浆一氧化氮（NO）水平和肺组织髓过氧化物酶（MPO）活性显著升高,在支气管肺泡灌洗液和肺组织中NO水平降低,白茶提取物和EGCG组均能改善NO失调,降低MPO活性;（4）白茶提取物和EGCG均能上调COPD小鼠单磷酸腺苷依赖的蛋白激酶（AMPK）磷酸化水平的下降;上述处理过程中均未见白茶提取物和EGCG对小鼠的肝毒性。综上,白茶提取物能够通过抗氧化、抗炎和调节NO失常来明显改善香烟烟雾诱导的小鼠COPD。 相似文献
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绿茶几种化学组分苦涩味非线性回归分析及在感官审评中的应用 总被引：2，自引：0，他引：2
为了定量分析茶汤苦涩味强度,采用感官评定法中的线性标度法和排序法,建立了EGCG和咖啡碱的呈味特征曲线（滋味强度与浓度关系）,以EGCG、咖啡碱和芦丁为主要参数建立了茶汤苦涩味强度定量函数,探讨了这3种主要呈味物质间的相互影响。芦丁能增加咖啡碱的苦味,但是芦丁对EGCG的滋味无明显影响,而咖啡碱对EGCG的涩味有明显增强作用。利用苦涩味强度定量函数对四川绿茶苦涩味偏重的成因进行了分析,对20个茶样的分析结果表明,模型对苦味的解释程度达78%~137%,对涩味的解释程度达68%~144%,较高的EGCG和咖啡碱含量可能是四川绿茶苦涩味偏重的主要原因。 相似文献
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EGCG纳米载体制备技术及其对EGCG活性影响的研究进展 总被引：1，自引：0，他引：1
表没食子儿茶素没食子酸酯(EGCG)是绿茶中最重要的生物活性成分,在肿瘤形成的各个阶段都有抑癌活性。纳米化途径是提高EGCG稳定性和生物利用度的有效技术之一。已有较多的研究表明,多类材料可用于制备纳米粒子作为EGCG载体,并在改善EGCG生物活性方面效果显著。本文按制备纳米粒子主要材料的不同,对各类纳米粒子的制备方法、特性及其在改善EGCG的生物活性方面的研究进行了分述,并对各种纳米粒的增效作用进行了归纳总结。 相似文献
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甲基化EGCG的研究现状及展望 总被引：1，自引：1，他引：0
EGCG3"Me于1982年首次从绿茶中被分离出来,并发现它具有潜在的抗过敏活性。近年来,甲基化的EGCG不断从茶叶和体内代谢物中被发现。本文对国内外甲基化EGCG的分离方法、功效和合成方法进行了综述。常见的甲基化EGCG分离方法包括葡聚糖凝胶（Sephadex LH-20）、高速逆流色谱、Toyopearl HW-40S中压柱层析、制备型液相色谱（pHPLC）等方法;甲基化EGCG在抗过敏性、抗细胞毒素、抑制脂肪氧化酶、抑制诱导型一氧化氮合成酶（iNOS）、保护肝细胞等方面都优于EGCG;甲基化EGCG的合成主要包括化学合成和生物合成两种途径。 相似文献
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Textile fibers were obtained from secondary polyethylene terephtalate (PET) and its mixtures with primary PET at initial orientation of 18000–33000 %, rate of additional orientation drawing 3.5–6.5 times and temperature of thermal fixation 363–413 K. The fibers’ tensile strength was found to decrease and elongation at break to increase with the decrease of their linear density under the conditions of fibers formation. For the fibers based on polymer mixtures, the presence of oxidized fragments in the secondary PET limited the compatibility of the two polymers which resulted in deteriorated tensile properties. The linear density (4–16 dtex), tensile strength (30–50 cN/tex) and elongation at break (20–60 %) of the PET fibers obtained were close to these for the industrially produced polymer fibers. The values of the average diameter of the fibers formed and oriented under laboratory conditions allows classifying them between the fine and the coarse textile fibers which makes them suitable for the textile industry. 相似文献
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Gas-exchange characteristics of potato (Solanum tuberosum L.) canopies were determined with crop enclosures under condition of optimal water supply, during soil water depletion, and during recovery from drought-stress. The plants were grown under a rainshelter in large containers with 2-m2 surface area. Control plants received water throughout the growth period. In Expt. 1, transient drought was imposed by interrupting water supply completely for 22 days. During the 33-day period of drought treatment in Expt. 2, the stressed plants received half the amount of water that was given to the control plants (irrigations 2–3 times per week).
During soil water depletion, stomatal conductance of the canopy was reduced earlier and more than photosynthesis. This resulted in a lower internal carbon dioxide concentration in the leaves of stressed plants and a higher ratio between photosynthesis and stomatal conductance. The value of that ratio increased as soil water potential dropped.
Water-use efficiency ( ) increased during drought stress. The cultivar Bintje showed a larger ratio between photosynthesis and stomatal conductance of the canopy and a higher than cv. Saturna, both for optimal water supply and during drought stress.
Photosynthesis and conductance of the canopy started to recover immediately upon rewatering, even when relative values had declined to 20–30% during the preceding stress period. After release from stress, the leaves in the top layer of the canopy had a higher stomatal conductance in treated plants than in control plants. 相似文献
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2017—2018年,在同安镇粮食产能区示范推广水稻病虫害绿色防控与统防统治融合技术模式,取得了显著成效。融合技术示范区比常规区减少用药2~3次,用药量减少37.6%,防治成本降低400元/hm^2;水稻产量增加12.8%,收益增加2 835元/hm^2。 相似文献
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《Journal of Crop Improvement》2013,27(1):313-324
Summary Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer. 相似文献
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生物质能作物——甘薯开发利用现状及趋势 总被引：13，自引：0，他引：13
甘薯是世界上重要的粮食、饲料、工业原料及新型能源用块根作物，在我国乃至世界再生能源开发中起到重大作用，其分布地域广，适应性强，沙荒地、岗坡地均可种植。生物产量高，而且种植栽培容易。甘薯含淀粉15％～30％，晒干率20％～35％，世界各国以薯干或淀粉为原料生产乙醇有着悠久的历史。随着全球能源的日趋紧张，乙醇作为一种可再生的环保燃料．将快速步入全球成品油市场，在替代汽油供应方面起到越来越大的作用。各国正在推行或制定燃料乙醇计划，并着眼于生物燃料乙醇应用方案，认为甘薯可能是摆脱将来粮食和能源危机的“最后一张王牌”。 相似文献
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为明确春季调控措施对冬小麦生长发育和籽粒产量的影响,以冬小麦品种石新828为材料进行田间试验,4个处理分别为:起身期追全部氮肥(除基肥外,下同)并叶面喷多效唑(N1);起身期追2/3氮肥并喷多效唑+拔节期追1/3氮肥(N2);起身期追1/3氮肥+拔节期追2/3氮肥(N3);拔节期追全部氮肥(N4)。生育期间测定群体和个体生育特性,成熟期调查产量性状。结果表明,N1和N2处理小麦拔节期的总茎数、叶面积指数(LAI)和干物质积累量均显著高于N4和N3处理。孕穗期N4和N3处理小麦的总茎数、LAI和干物质积累量显著高于N1和N2处理。开花到成熟期各处理的总茎数、LAI和干物质积累量差异均不显著。孕穗期前,不同处理的株高差异不显著,孕穗期后,N4处理的株高最高,且显著高于N1处理。各处理基部节间直径和中上部节间长的差异不显著,N4处理基部第一节间长度显著大于其他处理。随追氮时期前移或前期施氮量增多,不孕小穗数减少,结实小穗和穗粒数增加,N1比N4处理不孕小穗数显著减少,结实小穗和穗粒数显著增多。N1处理小麦成熟期的千粒重最高,且显著高于N4处理。N1处理的籽粒产量最高,且显著高于N3和N4处理。起身期追氮配合多效唑调控,可以获得比拔节期追氮更高的穗粒数和千粒重,从而获得更高的产量。 相似文献
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施镁量和施镁方法对烤烟生长发育和烟叶产量的影响 总被引：4，自引：0，他引：4
采用盆栽试验，研究施镁量和施镁方法对烤烟生长发育和烟叶产量的影响，结果表明：适量施用镁肥，可以促进烟草的生长发育、改善其农艺学性状，影响烟株对其它营养元素的吸收与积累，提高烟叶产量，并能使烟叶N，P，K，Ca等营养元素含量更趋协调。随着施镁量的增加，烟叶中镁含量提高10．7％～71．4％，烤烟单株吸镁量、叶片叶绿素含量、干物质产量分别提高17．6％～115．4％，1．9％～23．ooA和6．3％～25．7％，而对烟叶含钾量没有明显影响。在镁比较缺乏的土壤上，镁肥作基肥施比叶面喷施的效果好，基肥施镁结合叶面喷镁的效果最佳；叶面喷镁，肥料用量少、成本低、见效快，是一种有效的镁肥施用方法；提高镁肥用量，施镁的效果更加显著。 相似文献