黄酮类化合物结构与抗氧化活性关系研究

黄酮类化合物是一类在植物界广泛分布的多酚类天然产物。研究表明,黄酮类化合物具有抗氧化、抗癌、抗心脑血管疾病、抗炎、抗病毒、免疫调节等多种生理功能及药理作用。开展黄酮类化合物构效关系的研究,对从中草药中筛选出更有效、安全的药物,发现先导化合物十分必要。本文讨论抗氧化活性与黄酮类化合物结构的关系。     

细叶亚菊乙醇提取物体外抗氧化活性研究

对细叶亚菊全草75%乙醇提取物进行了总酚总黄酮含量测定并系统的检测其体外抗氧化活性。结果显示,细叶亚菊乙醇提取物所含总酚含量为32.7±2.0μg/ml,总黄酮含量为14.19±1.29μg/ml.实验结果显示DPPH的IC_(50)值为253.16μg/ml,ABTS的IC_(50)值为34.4μg/ml.抑制脂质过氧化实验结果显示浓度0.4mg/ml的细叶亚菊乙醇提取物的脂质过氧化抑制率为29.21%表现良好的抗氧化生物活性。细叶亚菊抗氧化活性为传统药理作用和其开发成新药物提供了基础数据。     

Dragon软件用于黄酮类化合物抗氧化活性的预测

以Dragon软件计算的Burden特征值作为变量,采用多元回归的方法对18个黄酮化合物的抗氧化活性建立定量结构-活性相关模型,所建模型的相关系数为0.950,用该模型对黄酮的抗氧化物活性进行预测,估算值和文献值接近。通过Jackknife法和交互检验证明该模型具有总体稳健性和良好的预测能力。     

响应面法优化草果黄酮的提取工艺及其抗氧化性能研究

目的:以草果干粉为原料,乙醇为提取液,确定微波-超声相结合提取草果中黄酮的最佳工艺条件.方法:对乙醇浓度、超声时间、微波时间等工艺条件进行单因素考察,黄酮得率为响应值,通过星点设计(Central Composite Design,CCD)试验建立数学模型进行响应面分析,确定最佳提取工艺条件;再考察其抗氧化活性的强弱.结果:草果黄酮的提取最佳工艺条件:乙醇浓度50％,超声时间40min,微波时间60 s,黄酮得率为4.1474％,黄酮含量为41.47 mg/g,与响应面分析模型的得率4.2518％接近;草果黄酮含量达到135.60 g/mL时,DPPH自由基清除率达到81.07％,DPPH自由基的半抑制率(IC50)值为23.85 g/mL.结论:证明该提取工艺稳定可靠,草果黄酮具有较强的抗氧化活性,可为草果进一步研究提供理论指导意义.     

柏属植物双黄酮药理活性研究

本文对存在于柏属植物中的双黄酮类化合物药理活性研究进行综述,总结近10年来从柏属植物中分离得到的双黄酮药理活性研究进展。双黄酮类化合物的化学结构不同,其药理活性也不同。列举出多种药理活性表现,如免疫及抗肿瘤作用、血液系统作用、抗菌及抗病毒作用、抗氧化活性作用等,为该类化合物的研究开发利用提供参考。     

荷叶衣服

上学碰到下雨的天气,同学们经常忘记带雨具,回到家就成了个落汤鸡,甚至引起感冒,既影响身体又影响学习。我想发明一种不沾水的衣服,它的外层仿照荷叶表面结构制成。荷叶具有微米一纳米双重结构,使其表面与水珠儿或尘埃的接触面积非常有限,因此水珠在叶面上滚动并能带走灰尘,而且水也不会留在荷叶表面。     

山楂黄酮提取工艺研究

对山楂总黄酮含量的提取,不同工艺影响很大。本文采用单因素和正交实验法方法研究不同工艺条件对山楂黄酮提取效率的影响,得出最佳浸提工艺及相关工艺参数。     

槲寄生总黄酮微波提取工艺及其抗氧化活性研究

采用不同的提取方法对槲寄生进行提取,并使用紫外分光光度法对提取物中的黄酮进行测定,检测波长为510nm。采用实验对槲寄生抗氧化活性进行研究。     

超临界CO2萃取荷叶挥发油工艺的研究

通过超临界CO2萃取均匀设计实验和微波辅助萃取荷叶挥发油的正交实验比较，考察影响提取的主要图素，寻求最佳萃取工艺。     

Electrowetting on a lotus leaf

Electrowetting on dielectrics has been widely used to manipulate and control microliter or nanoliter liquids in micro-total-analysis systems and laboratory on a chip. We carried out experiments on electrowetting on a lotus leaf, which is quite different from the equipotential plate used in conventional electrowetting. This has not been reported in the past. The lotus leaf is superhydrophobic and a weak conductor, so the droplet can be easily actuated on it through electrical potential gradient. The capillary motion of the droplet was recorded by a high-speed camera. The droplet moved toward the counterelectrode to fulfill the actuation. The actuation speed could be of the order of 10 mm∕s. The actuation time is of the order of 10 ms.     

西藏八角莲生物学特性及栽培技术简介

本文对抗癌药用植物西藏八角莲的药用价值、形态学特征、生物学特性、生境分布及栽培技术等方面进行总结，为西藏八角莲的开发利用提供重要信息。     

烟雾吸入伤早期氧化与抗氧化动态平衡变化的实验研究

采用大鼠烟雾吸入伤模型，动态观察了伤后血浆、支气管肺泡灌洗液（ＢＡＬＦ）和肺组织中超氧化物歧化酶（ＳＯＤ）活性、丙二醛（ＭＤＡ）和共轭二烯（ＣＤ）含量的变化，辅以动脉血气分析、肺水量测定、ＢＡＬＦ中白细胞分类计数和病理检查．结果发现，伤后动物出现急性呼吸衰竭和严重肺水肿，肺内大量炎细胞聚集浸润；血浆、ＢＡＬＦ及肺组织中ＳＯＤ活性明显降低，ＣＤ和ＭＤＡ含量显著增加，ＭＤＡ／ＳＯＤ比值亦明显增高，且与ＢＡＬＦ中中性粒细胞数增加显著相关，提示氧化与抗氧化平衡失调可能在急性烟雾吸入性肺损伤的发生发展中起重要作用     

水稻细菌性条斑病菌的相关研究

水稻细菌性条斑病菌(Xanthomonas oryzae pathovar oryzicola,简称Xoc),它是使水稻致病的主要病原菌之一,其引发的水稻细菌性条斑病目前还没有有效的方法控制。文章主要介绍了水稻细菌性条斑病的病原菌、致病机理、研究方法以及防治措施。     

Varied academic activities of Sino-Aussie hydrologists in Beijing

The August of 2007 is a busy month for the China-Australia Center on Water Resources Research affiliated to the CAS Institute of Geographical Sciences and Natural Resources Research (IGSNRR) in Beijing. Acting as a bridge between scholars of the two countries in the field, it brought together Chinese researchers and their Australian colleagues to take part in various academic activities ranging from workshops to field studies.     

The innovative activities of researchers in Italian industry

In recent years a number of “science indicators” have been constructed in order to gain deeper insight into the working and the impact of scientific and technological systems. Most of these indicators, drawing on data which are usually collected from various sources with different purposes, lack, to a certain extent, coherence and sometimes comparability.A more integrated approach was adopted in the study underlying this paper: the data were gathered from the principal figure in the innovation process, i.e. the researcher. A sample of researchers working in Italian industry were interviewed and supplied information on, amongst other things, their activities and the relative results. Not surprisingly, the results of this survey do not necessarily conform with other sources currently available. However, it should be realized that the information provided by the researchers, although inherently biased, is far more detailed, and represents a valuable source of knowledge of the situation not only of the single persons involved but also of the organization in which they operate.The obvious lesson is that only through the cross-checking and the integration of data coming from different types of sources is it possible to achieve a reliable and faithful picture of the complex phenomenon under review.In the paper an analysis is made of the various activities performed by researchers in Italian industry (research, development, control, design, technical assistance, organization, updating, consultancy, etc.) and of the technological objectives of such activities (new or improved products, processes, materials). Data are also shown on the criteria which researchers judge more suitable in evaluating their performance, as well as on the researchers' output in terms of articles, monographs, papers presented at conferences, patents and inventions.     

专利引用过程中的知识活动探析

摘要：专利引用过程中蕴含着丰富的知识活动。由于专利文献与论文文献的相似性,可以利用科学计量学的相关理论和方法来对专利引用过程中的知识活动进行深入揭示和可视化展示。研究结果显示引用过程中包含着知识的产生与传播、知识的发展与重组等活动。在中观和宏观尺度上来看,微观层次的知识发展与重组可能会导致技术范式的变更,这类似于托马斯·库恩提出的科学革命到来之前科学范式的更替。     

葡萄科植物叶表皮特征及其系统学意义

在光学显微镜和扫描电镜下，对葡萄科Vitaceae11属37种代表植物的叶表皮特征进行了观察，发现该科植物叶表皮细胞形状为无规则形或多边形，垂周壁一般为平直、弓形或浅波状;气孔器通常仅分布在下表皮（火筒树属Leea偶尔可在上表皮观察到），除无规则型（地锦属Parthenocissus、俞藤属Yua、葡萄属Vitis、蛇葡萄属Ampelopsis和酸蔹藤属Ampelocissus）最为常见外，不等细胞型（火筒树属）、短平列型（白粉藤属Cissus、乌蔹莓属Cayratia和崖爬藤属Tetrastigma）、     

Electron diffraction studies of etched al leaf films

Anomalies occurring in electron diffraction patterns of etched An leaf films were studied. The anomalies were of two kinds, extra lines and orientation effects. The extra lines, in agreement with the report of Thomson and Cochrane, were attributed to contamination of the films by some long chain compound. The orientation effects consisted of a variation of the intensities of several of the lines of the An patterns obtained from the intensity of these same lines as observed in standard patterns of randomly-oriented Au. These abnormal intensities evidenced the existence of the [100] crystal direction as an axis of orientation perpendicular to the face of the film. A second orientation effect, the arcing of some of the lines of the Au patterns, indicated a second axis of orientation parallel to the face of the film but insufficient evidence prevented the identification of this axis of orientation.Results of the orientation study confirm the findings of other investigators, particularly those of Trillat and Hirsch.     

中国梅花草属植物的叶表皮特征及其系统学意义

利用光学显微镜和扫描电镜对梅花草属Parnassia 30种植物的叶表皮进行了观察。结果表明:气孔器普遍存在于叶的下表皮,少数种的上表皮也有分布,均为无规则型。叶表皮细胞形状为多边形或不规则形;垂周壁式样可区分为近平直、浅波状和波状。在扫描电镜下,叶表皮气孔器外拱盖内缘为近平滑、浅波状或波状;一些种的保卫细胞两端有加厚;角质膜条纹状,有的条纹隆起,有的条纹上附有颗粒或小孔穴。气孔器类型及下表皮细胞形状的一致性表明梅花草属是一个自然分类群;sect. Saxifragastrum叶表皮特征具有多样性显示该组可能是一个复合群;突隔梅花草P. delavayi属于subsect. Xiphosandra,其气孔下陷,与其细胞学特征相似,支持独立为一组;此外,气孔器的分布、保卫细胞两端加厚、气孔器外拱盖内缘形态以及角质膜等特征对该属部分种的区分有一定的参考价值。