Highly Oxygenated Triterpenoids from the Marine Red Alga Laurencia mariannensis (Rhodomelaceae)

Two new and one known squalenoid-derived triterpenoids. namely, laurenmariannol (1) and (21 alpha)-21-hydroxythyrsiferol (2). and the known thyrsiferol (3) were isolated and identified from the marine red alga Laurencia mariannensis, which was collected off the coast of Hainan and Weizhou Islands of China. The structures of these compounds were established by means of spectroscopic analyses, as well as by comparison with literature data. Compounds I and 2 displayed significant cytotoxic activity against P-388 tumor cells with IC50 values of 0.6 and 6.6 mu g/ml, respectively.

Terpenes and polybromoindoles from the marine red alga Laurencia decumbens (Rhodomelaceae)

Two new brominated diterpenes, namely, laurendecumtriol (1) and 11-O-deacetylpinnaterpene C (2), one new polybromoindole, 2,3,4,6-tetrabromo-1-methyl-1H-indole (7), and six known natural products were isolated and identified from the marine red alga Laurencia decumbens. Their structures were elucidated on the basis of detailed spectroscopic and mass-spectrometric analysis as well as by comparison with literature data. Based on 2D-NMR experiments, the previously reported NMR data for pinnaterpene C (3) were reassigned.

Dioxopiperazine Alkaloids Produced by the Marine Mangrove Derived Endophytic Fungus Eurotium rubrum

Cultivation of the fungal strain Eurotium rubrum, an endophytic fungus that was isolated from the inner tissue of stems of the mangrove plant Hibiscus tiliaceus, resulted in the isolation of two new dioxopiperazine derivatives, namely, dehydrovariecolorin L (1) and dehydroechinulin (2), together with eight known dioxopiperazine compounds including variecolorin L (3), echinulin (4), isoechinulin A (5), dihydroxyisoechinulin A (6), preechinulin (7), neoechinulin A (8), neoechinulin E (9), and cryptoechinuline D (10). The structures of the isolated compounds were determined by extensive analysis of their spectroscopic data as well as by comparison with literature. Compounds 1, 2, 9, and 10 were investigated for their a,a-diphenyl-beta-picrylhydrazyl (DPPH) radical-scavenging activity. In addition, the new compounds, 1 and 2, were evaluated for their cytotoxic activity against the P-388, HL-60, and A549 cell lines.

Preparation of porous chitosan/agarose microsphere and its R-phycoerythrin release properties

The chitosan microspheres (CS-CL) were prepared by suspension crosslinking method and used as carriers of R-phycoerythrin (R-PE). In this study, R-PE was loaded in the microspheres and released in vitro. The effects of pH value, temperature, ionic strength, and R-PE concentration on loading efficiency and release behavior were discussed. A novel microsphere that contained agarose (CS-AR MP) was prepared and the basic loading and releasing behavior for R-PE of this kind of new micro-spheres were also investigated. The results showed that all these chitosan microspheres have the ability to control-release R-PE. The addition of agarose may somewhat accelerate the release rate of R-PE from microspheres and reduce the capacity of adsorption for R-PE. (c) 2006 Wiley Periodicals, Inc.

大型海藻和滤食性贝类在鱼类养殖系统中的生态效应

无机营养盐是海水鱼类养殖主要的污染物之一.近年来,在“清洁生产”和“生态养殖”理论的指导下,将鱼类与其他养殖种类进行混养的综合养殖模式成为研究的热点.该文在室内封闭水体中进行了许多平鲉（Ssbastesschlegeli,同种异名黑鲪）分别和龙须菜（Gracilarialemaneiformis）、海湾扇贝（Argopectenirradians）的混养试验,监测了水体理化因子和生物因子的变化规律,测定了养殖生物的生长情况,藻贝在鱼类养殖系统中的生态效应.

Determination of Total Arsenic and Arsenic Metabolites in Human Liver Hepatocytes

The effects of direct sampling and three digestion methods were investigated on the determination of arsenic in Chang liver hepatocytes after ultrasonic disintegration were investigated. The results showed that the efficiency of microwave digestion and obturator digestion was better than cold digestion and direct sampling. The day precision (present as RSD) of microwave digestion and obturator digestion were 2.1% and 1.2% the inter-day precision were 1.2% and 2.0%, respectively. The spike recovery for the total As in the sample is 95.7% - 108.1%. The As detection limits with these four sample treatment methods (including direct sampling) were 0.74 - 0.93 mu g/L. In addition, arsenic speciation in Chang liver hepatocytes was also analyzed using the hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. The experimental results indicated that dimethylarsinic acid (DMA) and an intermediate metabolite of DMA were found lit Chang liver hepatocytes besides inorganic arsenic (As(III) and As(V)).

服务机器人路径规划技术研究

随着技术的发展和数字产品的价格下降，家用机器人必将成为未来数字家庭的主导。正如家用机器人生产厂商iRobot的CEO科林·安格尔所说：“我认为，完全有理由想像，10年之后每个家庭都将拥有一台机器人。”路径规划技术是移动机器人导航系统中不可缺少的重要组成部分，不仅是移动机器人完成任务的安全保障，同时也是移动机器人智能化程度的重要标志。 本论文以新松公司“家用服务机器人的研究开发”项目为背景，对服务机器人的路径规划系统中的重点和难点问题进行了深入的研究，主要工作如下： 在嵌入式微处理器ARM7上实现了服务机器人的路径规划系统，完成了超声波传感器和红外传感器的采集和标定，并通过仿真研究和实验研究两方面对机器人的路径规划系统进行分析和设计。 在MATLAB GUI的仿真平台上，采用改进斥力势场函数解决了障碍物附近目标点不可达问题，通过引入引导点解决机器人在‘U’型区域内的震荡问题。在实验中，首先采用改进势场函数实现了机器人的折线规划方法，基于此算法，实现了机器人在固定范围内漫游的功能；通过改进折线规划方法，提出了弧形规划算法；通过引入人工协调场，解决了机器人、障碍物与目标点在一条直线上时与长形障碍物的碰撞问题；最后再加上各种安全措施，保证机器人在躲避障碍物的同时，能以一种比较平滑、优美的曲线到达目标点。 本论文首先在仿真中实现基本的规划算法，以服务机器人为平台，通过实验，不断发现新问题，提出新的改进算法，最后再在实验中进行验证。实验结果表明本文设计的路径规划算法能够实现机器人以平滑优美的曲线在复杂环境中的路径规划功能。

地震勘探三维可视化方法研究与实现

This thesis mainly studies the technologies of 3-D seismic visualization and Graphic User Interface of seismic processing software. By studying Computer Graphics and 3-D geological modeling, the author designs and implements the visualization module of seismic data processing software using OpenGL and Motif. Setting seismic visualization flow as the subject, NURBS surface approximation and Delaunay Triangulation as the two different methods, the thesis discusses the key algorithms and technologies of seismic visualization and attempts to apply Octree Space Partitioning and Mip Mapping to enhance system performance. According to the research mentioned above, in view of portability and scalability, the author adopts Object-oriented Analysis and Object-oriented Design, uses standard C++ as programming language, OpenGL as 3-D graphics library and Motif as GUI developing tool to implement the seismic visualization framework on SGI Irix platform. This thesis also studies the solution of fluid equations in porous media. 2-D alternating direction implicit procedure has been turned into 3-D successive over relaxation iteration, which possesses such virtues as faster computing speed, faster convergence rate, better adaptability to heterogeneous media and less memory demanding.

New method for analysis of Chinese herbal complex prescription and its application

Traditional Chinese medicine (TCM) is a great treasure of China, the analysis of which is an arduous task. The viewpoint that all chemical constituents of Chinese herbal complex prescription should be analyzed as a black box is elucidated for the first time. Intelligent multi-mode multi-column chromatographic system (IMMCC) with its hybrids is the basic method and HPLC Unified Method is the breakthrough for the black box analysis. Dang-Gui-Bu-Xue-Tang was selected as a typical TCM and a systematic separation method from non-aqueous mobile phase to pure water mobile phase was put forward in order to convert unknown sample to known sample. The a, c values and UV spectra of 66 components of Astragalus, 78 components of Angelica and 71 components of Dang-Gui-Bu-Xue-Tang were obtained. Intelligent optimization and peak identification method and software for complex samples were developed and the optimum multi-step multi-binary gradient curve of mobile phase for Astragalus was ascertained. The maximum error and minimum error of predicted retention time for all components of Astragalus are 8.62% and 0.05% respectively. All components of Astragalus were compared with those of Angelica and it is found that many components of Astragalus are the same as those of Angelica, while the contents of these components are different. Many components of Dang-Gui-Bu-Xue-Tang are also the same as those of Astragalus and Angelica with different contents.