藏红花花瓣粗多糖的体外抗氧化活性研究

采用水提醇沉法提取藏红花花瓣中的多糖,得率为3.75%.联合蒽酮-硫酸法和DNS法测得多糖纯度为68.34%.对粗多糖的体外抗氧化活性进行测定,结果表明,粗多糖具有一定的抗氧化活性,抗氧化能力指数(ORAC)值为0.572μmol TE/mg;其对ABTS+、DPPH和羟自由基具有一定的清除能力,半数清除浓度EC50分别为76.26μg/mL、165.5μg/mL和880.4μg/mL.     

地黄功能因子提取物体外抗氧化活性及α-葡萄糖苷酶抑制活性研究

通过体外试验，探讨了DHTW抗氧化活性及α-葡萄糖苷酶的抑制活性，为地黄降糖功能因子的开发利用提供理论依据.采用紫外分光光度法(UV)测定DHTW清除DPPH、ABTS等自由基的能力，利用酶标仪测定DHTW抑制α-葡萄糖苷酶的活性.结果表明：(1)DHTW均具有抗氧化活性，质量浓度在0～6 mg/mL内，随着浓度的增加，抗氧化活性也不断增加，当溶液达到一定浓度后，抗氧化性趋于稳定.(2)DHTW的DPPH自由基清除能力IC₅₀值分别为：醇洗脱物DHY(0.087 mg/mL)、粗提物DHC(2.987 mg/mL)、水洗脱物DHS(3.024 mg/mL)，故自由基清除能力表现为：DHY>DHC>DHS.(3)DHTW的ABTS自由基清除能力IC₅₀值分别为：DHY(0.137 mg/mL)、DHC(1.463 mg/mL)、DHS(2.168 mg/mL),ABTS自由基清除率表现为：DHY>DHC>DHS.(4)DHTW对α-葡萄糖苷酶均有明显的抑制作用，其中，DHY有较明显的抑制能力，α-葡萄糖苷酶抑制活性明显优...     

翘鳞肉齿菌多糖的分离纯化及抗氧化活性的研究

为了分离纯化翘鳞肉齿菌多糖,解析其结构特征,并研究其抗氧化活性.运用DEAE-cellulose column进行柱层析分离纯化翘鳞肉齿菌多糖,高效凝胶渗透色谱(HPGPC)方法研究其均重分子量,通过红外光谱解析其结构特征,进一步研究其对羟基自由基(·OH)、1,1-二苯基-2-苦基肼自由基(DPPH-)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+)的清除作用,同时研究了翘鳞肉齿菌多糖在H2O2作用下对PC12细胞的保护能力.其结果显示从四川省小金县翘鳞肉齿菌子实体分离纯化得到一种水溶性杂多糖(SIKP-1)纯品,其重均分量约为2.0×104 Da.通过化学方法研究了不同质量浓度的翘鳞肉齿菌多糖(SIKP-1)抗氧化活性,结果表明:当SIKP-1质量浓度为0.1mg/mL时,其对DPPH-自由基的清除率可达到40.63%;当SIKP-1质量浓度达到0.32mg/mL时,对·OH自由基的清除率可达到51.61%;当SIKP-1的质量浓度为3mg/mL时,对ABTS+自由基的清除率可达69.75%;在细胞生物学实验中,结果显示在用终质量浓度为0.5,1,2 mg/mL的SIKP-1处理下,PC12能免于H2O2的损伤,随着剂量的增加其存活率越高,分别为15.89%,27.60%,29.36%.综上试验结果显示,翘鳞肉齿菌多糖(SIKP-1)具有显著的抗氧化功能,因此可以作为一种理想的抗氧化剂资源.     

红参多糖体外抗氧化的研究

目的:研究不同醇沉浓度提取的红参多糖的体外抗氧化能力,并用Vc作为阳性对照。方法:用紫外分光光度法研究红参多糖和Vc清除DPPH自由基和羟自由基的能力来评价其抗氧化活性。结果:80%醇沉的红参多糖对DPPH自由基、羟自由基清除效果最好,IC_(50)分别为0.81,0.44mg/mL;30%醇沉的红参多糖对DPPH自由基也有清除效果,但相对较弱,IC_(50)为12.74mg/mL;50%醇沉的红参多糖对羟自由基的清除效果最差。结论:红参多糖具有较强的抗氧化作用,其中80%醇沉红参多糖抗氧化作用最强。     

大孔吸附树脂提取粗壮女贞苦丁茶总黄酮及抗氧化活性

目的:研究大孔吸附树脂分离纯化苦丁茶总黄酮的最佳工艺及黄酮化合物的抗氧化活性.方法:采用大孔吸附树脂法获得总黄酮.利用紫外分光光度法测定苦丁茶总黄酮不同浓度下在体外对DPPH自由基、超氧阴离子自由基、羟基自由基和ABTS自由基的清除能力.结果:大孔吸附树脂提取最佳工艺为上样流速为3 mL/min,上样浓度为1.2 mg/mL,其黄酮类化合物在体外抗氧化的能力包括ABTS自由基、DPPH自由基、超氧阴离子自由基和羟基自由基,在不同浓度下的最大清除能力分别为88.65%、87.94%、89.11%和73.21%.结论:总黄酮对4种自由基有良好的清除效果.     

新疆芍药与窄叶芍药根中多糖含量测定及体外抗氧化活性的研究

为探讨新疆芍药和窄叶芍药根中多糖的含量并评价其多糖体外抗氧化活性。采用水提醇沉法提取多糖,用Sevage法除蛋白、活性碳脱色,并用苯酚-硫酸比色法测定多糖的含量;并采用1,1-二苯基-2-硝基苯肼自由基清除法(DPPH法)和2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二氨盐自由基清除法(ABTS法)对提取的多糖进行体外活性评价。结果显示:纯化后窄叶芍药和新疆芍药的多糖含量达0.82%和0.78%;窄叶芍药和新疆芍药多糖对DPPH自由基的IC50分别为0.07 mg/m L和0.13 mg/m L;而两者对ABTS自由基的IC50分别为0.075 mg/m L和0.096mg/m L。由此可知,本文建立的测定多糖含量的方法简便、准确、重现性好;且窄叶芍药和新疆芍药对清除DPPH与ABTS自由基均具有一定抗氧化活性。     

蒙药述达格-4抗氧化活性研究

通过建立蒙药述达格-4体外抗氧化活性测定方法,明确述达格-4的抗氧化作用。采用DPPH自由基清除率、FRAP法对Fe~(3+)的还原能力、TEAC法对ABTS自由基的清除率及总抗氧化能力(T-AOC)试剂盒等综合评价述达格-4的抗氧化能力。结果显示,述达格-4浓度为0.32mg/mL时,DPPH自由基清除率为77.08%,IC_(50)值为0.08982mg/mL;浓度为2.383mg/mL时,对Fe~(3+)的还原能力最高,吸光度达到最大值0.734;浓度为0.321mg/mL时,对ABTS自由基清除率可达到99.77%,IC_(50)值为0.1050mg/mL; 200μL浓度为2.798mg/mL的述达格-4总抗氧化能力相当于0.8448mmol的Trolox。说明建立的方法适用于蒙药述达格-4体外抗氧化活性测定,且抗氧化活性能力大于黑枸杞,述达格-4有较强的抗氧化活性。     

玉竹多糖的抗氧化作用研究

为研究玉竹多糖的体外抗氧化活性和清除自由基作用,采用体外化学体系研究玉竹多糖对超氧阴离子(O-2·)、羟自由基(·OH)、1,1-二苯基-2苦苯肼自由基(DPPH·)和过氧化氢(H2O2)的清除能力。结果表明:玉竹多糖对超氧阴离子(O-2·)、过氧化氢(H2O2)和1,1-二苯基-2-苦苯肼自由基(DPPH·)具有较强的清除能力,其EC50值分别为0.38 mg/mL(Vc为0.09 mg/mL)、0.65 mg/mL(Vc为0.70 mg/mL)和0.43 mg/mL(Vc为0.06 mg/mL);但对羟自由基(·OH)的清除能力较弱,其EC50值为14.7 mg/mL(Vc为0.34 mg/mL)。玉竹多糖具有较好的体外抗氧化活性。     

人参多糖提取工艺优化及体外抗氧化作用的研究

目的 通过优化人参多糖(Ginseng Polysaccharide)的提取工艺,探讨人参多糖的体外抗氧化能力.方法 应用水提醇沉法,在料液比、提取温度、提取时间、提取次数单因素试验的基础上,采用4因素3水平正交分析法优化人参多糖的提取工艺,同时对人参多糖的总抗氧化能力(FRAP法)、清除1,1-二苯基苦基苯肼自由基(DPPH·)和羟基自由基(·OH)的能力进行测定.结果 影响多糖得率的顺序依次为提取温度>料液比>提取时间>提取次数,此研究确定了人参多糖的最优提取工艺:提取温度60℃,料液比m(g):V(mL)=1:30,提取时间60 min,提取次数2次,在此条件下获得的最高得率为(9.87±0.35)％.人参多糖清除DPPH自由基的IC50值为7.58μg/mL,清除羟自由基的IC50值为145.72μg/mL.体外抗氧化结果 表明:人参多糖的总抗氧化能力、清除DPPH自由基和羟自由基的能力均强于相同浓度下水溶性维生素E,且呈剂量依赖性增加.结论 人参多糖具有较好的体外抗氧化能力.     

杏鲍菇粗多糖的抗氧化活性研究

对杏鲍菇子实体、菌丝体和发酵液粗多糖清除DPPH自由基、羟自由基的能力、铁离子螯合能力以及还原力进行了比较分析,结果表明:菌丝体、发酵液粗多糖清除DPPH自由基能力较强,清除率EC50值分别为4.15和4.81mg/mL;子实体、菌丝体和发酵液粗多糖清除羟自由基、螯合铁离子的能力较强,羟自由基清除率EC50值分别为1.27、1.31和3.54mg/mL,铁离子螯合能力EC50值分别为3.01、1.53和4.17mg/mL;在一定浓度范围内,多糖浓度增加其清除DPPH自由基、羟自由基的能力以及铁离子螯合能力亦增强,并呈现良好的量效关系.实验浓度范围内,3种粗多糖的还原力均较弱.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to