大孔树脂分离纯化柚皮黄酮的研究   总被引：16，自引：5，他引：16  

李春美  钟朝辉  窦宏亮  吴宝利  谢笔钧 《农业工程学报》2006,22(3):153-157

该文以总黄酮含量和总黄酮回收率为考察指标，研究了大孔树脂分离纯化柚皮黄酮的工艺。结果表明：AB-8型树脂对柚皮总黄酮有较好的吸附分离性能，是分离纯化柚皮黄酮的适宜大孔树脂；AB-8型大孔树脂分离纯化柚皮黄酮的最佳工艺条件为：柱体积为160 mL，柚皮提取物上样量为62.5 mg/mL(以湿树脂体积计)，先用pH 4的水淋洗，再用30%的乙醇洗脱，洗脱剂用量为2.5～3倍湿树脂体积。AB-8大孔树脂按上述确定的吸附洗脱条件可重复使用3次。柚皮黄酮经上述工艺纯化后总黄酮含量达到39.67%，总黄酮回收率为62.48%。对经AB-8大孔树脂纯化后的柚皮黄酮进行高效液相色谱(HPLC)分析发现，柚皮黄酮主要为黄酮甙类。  相似文献   

不同大豆品种田间结瘤固氮有效性的评价   总被引：1，自引：0，他引：1  

李新民  窦新田 《大豆科学》1993,12(4):308-312

利用相关和通径分析对田间种植的４０份大豆品种（系）的结瘤固氮性状（结瘤分级，有效瘤数，有效瘤干重，有效结瘤指数，植株干重和植株全氮含量）的研究表明：有效瘤数，有效瘤重和有效结瘤指数可以有效地作为对大豆固氮种质的评价指标，其相对重要性为有效瘤重＞有效瘤数＞有效结瘤指数。在此基础上并结合籽粒产量因子筛选出２份结瘤固氮及产量较高的种质。研究同时也获得了七份在有效瘤重与有效瘤数或有效瘤重与效结瘤指数上表现  相似文献   

油菜黄宽条跳甲生物学及药剂拌种防治研究     

关明卓  窦玉珍  赵焕明  王孝德  赵进生 《内蒙古农业大学学报(自然科学版)》1995,(2)

本文查明内蒙古后山（阴山山脉以北及大兴安岭岭北）地区为害油菜的跳甲共有６种，内蒙古中、西部以黄宽条跳甲Ｐｈｙｌｌｏｔｒｅｔａｈｕ一ｍｉｌｉｓＷｅｉｓｅ为优势种，呼伦贝尔盟岭北地区主要种类是黄曲条跳甲ＰｈｙｌｌｏｔｒｅａｔａｓｔｒｉｏｌａｔａＦａｂ一ｒｉｃｉｕｓ。黄宽条跳甲在后山地区每年发生１代，以成虫越冬。翌年６月上、中旬大量发生为害，主要咬食刚出土的幼苗。药剂试验结果表明，４０％甲基异柳磷乳油按种子重量的０．５％和０．８％用药量（商品量）拌种，３５％大扶农种衣剂按种子重量的０．３％和０．５％用药量（商品量）拌种，在播后２５ｄ，其校正死亡率达到８１．１％以上，相对防效达９５．４％以上，大面积防治效果平均达９６．６％。  相似文献   

奶牛不排卵状况的研究综述   总被引：2，自引：0，他引：2  

杨炜峰  窦忠英  高志敏 《乳业科学与技术》2003,26(2):88-91

卵泡生长可分为三个阶段：卵泡出现；卵泡的选择优势化与闭锁分离；卵泡排卵。不排卵的情况可分为：①生长卵泡不能生长至“分离期”。原因可能是极度的营养缺乏。②卵泡可生长到“分离期”，但没有达到排卵体积。这方面研究得较多，认为这类牛比正常牛有更强的E2对GnRH／LH的负反馈，在营养不良或吮乳时可引起这类不排卵状况。③卵泡生长的最终体积大于排卵卵泡，这类牛的特征是下丘脑对E2的正反馈作用不敏感；高产奶牛常见。对于第一种情况，关键在于预防，提高育成期的饲管水平。后两种常见的不排卵状况是由于下丘脑对E2反应的敏感性改变；常用增加血液循环中P4的浓度改变GnRH／LH释放的脉冲以协助卵泡最后阶段的生长，或重新建立下丘脑对E2的正反馈来治疗。  相似文献   

核型分析方法研究及进展   总被引：1，自引：0，他引：1  

窦笑菊 《安徽农学通报》2012,18(13):32-34

染色体核型分析是生物学研究中常用的实验方法。核型分析技术区别于传统的形态鉴别,在细胞水平上研究染色体特征,并以此为依据对植物进行分类,结果更加真实准确,对于植物分类、进化过程、以及属种间关系具有重要的应用价值。该文综述了核型分析研究的发展过程,指出了目前实验中存在的问题,并对其发展前景进行展望。  相似文献   

Addition of citric acid to enhance the bioleaching chalcopyrite tailings   总被引：1，自引：0，他引：1  

LI Dongwei  LIANG Zhirong  JIAO Binquan  LI Dou 《保鲜与加工》2012,(11):117-121

The effect of mixed sulphur bacilli on the bioleaching of chalcopyrite tailings in shake flask and the effect of different citric acid concentrations and slurry densities on leaching tailings are studied. The results show that the concentration of citric acid in a certain range can promote chalcopyrite tailings bioleaching, and the highest of leaching rate is 44.8%. The citric acid concentration and slurry density directly affect the oxidation activity of bacteria and the effect of leaching.  相似文献   

Cytotoxic, cytoprotective and antioxidant effects of isolated phenolic compounds from fresh ginger     

Peng F  Tao Q  Wu X  Dou H  Spencer S  Mang C  Xu L  Sun L  Zhao Y  Li H  Zeng S  Liu G  Hao X 《Fitoterapia》2012,83(3):568-585

Twenty-nine phenolic compounds were isolated from the root bark of fresh (Yunnan) ginger and their structures fully characterized. Selected compounds were divided into structural categories and twelve compounds subjected to in-vitro assays including DPPH radical scavenging, xanthine-oxidase inhibition, monoamine oxidase inhibition, rat-brain homogenate lipid peroxidation, and rat pheochromocytoma PC12 cell and primary liver cell viability to determine their antioxidant and cytoprotective properties. Isolated compounds were also tested against nine human tumor cell lines to characterize anticancer potency. Several diarylheptanoids and epoxidic diarylheptanoids were effective DPPH radical scavengers and moderately effective at inhibiting xanthine oxidase. An enone–dione analog of 6-shogaol (compound 2) was isolated and identified to be most effective at protecting PC12 cells from H₂O₂-induced damage. Almost all tested compounds inhibited lipid peroxidation. Three compounds, 6-shogaol, 10-gingerol and an enone-diarylheptanoid analog of curcumin (compound 6) were identified to be cytotoxic in cell lines tested, with KB and HL60 cells most susceptible to 6-shogaol and the curcumin analog with IC₅₀ < 10 μM. QSAR analysis revealed cytotoxicity was related to compound lipophilicity and chemical reactivity. In conclusion, we observed distinct compounds in fresh ginger to have biological activities relevant in diseases associated with reactive oxygen species.  相似文献   

长期施肥对黑土团聚体中腐殖物质组成的影响   总被引：5，自引：0，他引：5  

李凯  窦森  韩晓增  陈辉  周桂玉 《土壤学报》2010,47(3):579-583

腐殖物质(HS)是土壤有机质的主体,在土壤固碳方面具有重要作用[1],近些年来,在土壤有机质化学研究中越来越受到重视。团聚体是土壤有机质(SOM)分解转化和HS形成的最主要“场所”,土壤中的一切生物化学活动均在这一骨架内进行(包括土壤腐殖化作用)。在正常的或特定的条件下,不仅微生物主导的腐殖化作用需要合适的“场所”,而且所形成的HS也只有在合适的“场所”或者说与土壤矿质部分相结合才能长时间保存[2-3]。这种“场所”或者说有机无机结合状况,是制约整个土壤固碳反应的关键。但至今为止关于这种“场所”(团聚体)的固碳机制尚不清楚,特别是很少注重HS化学方面。团聚体和HS二者关系密切,不可分割。可以假  相似文献   

饲料添加剂牛至油中香芹酚和百里香酚含量的测定   总被引：1，自引：0，他引：1  

窦茂鑫  赵迪  侯永清  吴涛 《饲料工业》2013,(20)

试验建立了高效液相色谱法测定饲料添加剂牛至油中香芹酚和百里香酚含量的方法。采用高效液相色谱法,色谱柱Diamonsil C18(2)柱,流动相为甲醇-水-冰醋酸(60??4??2),检测波长274 nm,流速1.0 ml/min。结果显示,牛至油中香芹酚含量为37.81%,百里香酚含量为7.05%,香芹酚和百里香酚的回收率分别为98.2%、98.4%,变异系数分别为1.0%、1.3%。试验为牛至油中香芹酚和百里香酚的检测提供了准确、灵敏、可靠的分析方法。  相似文献   

Characteristics of soil seed bank in plantation forest in the rocky mountain region of Beijing, China   总被引：1，自引：0，他引：1  

HU Zeng-hui  YANG Yang  LENG Ping-sheng  DOU De-quan  ZHANG Bo  HOU Bing-fei 《林业研究》2013,24(1):91-97

We investigated characteristics (scales and composition) of soil seed banks at eight study sites in the rocky mountain region of Beijing by seed identification and germination monitoring. We also surveyed the vegetation communities at the eight study sites to explore the role of soil seed banks in vegetation restoration. The storage capacity of soil seed banks at the eight sites ranked from 766.26 to 2461.92 seeds·m -2 . A total of 23 plant species were found in soil seed banks, of which 63 80% of seeds were herbs in various soil layers and 60% of seeds were located in the soil layer at 0 5cm depth. Biodiversity indices indicated clear differences in species diversity of soil seed banks among different plant communities. The species composition of aboveground vegetation showed low similarity with that based on soil seed banks. In the above- ground plant community, the afforestation tree species showed high importance values. The plant species originating from soil seed banks represented natural regeneration, which also showed relatively high importance values. This study suggests that in the rocky mountain region of Beijing the soil seed banks played a key role in the transformation from pure plantation forest to near-natural forest, promoting natural ecological processes, and the role of the seed banks in vegetation restoration was important to the improvement of ecological restoration methods.  相似文献