Evoked potentials: three-dimensional display

Procedures are described for displaying large numbers of evoked potentials. A photographic superposition of average evoked responses, with the concurrent modulation of the brightness of each trace, yields a display having the appearance of a three-dimensional surface formed from hundreds of average responses.     

海量图形数据的存储与调度

采用基于三角形二叉树剖分方式的海量数据存储方式,并通过划分数据逻辑粒度进行海量数据高效调度的数据处理方法,使得图形数据的处理效率得到显著的提高.     

Creation and manipulation of three-dimensional optically trapped structures

An interferometric pattern between two annular laser beams is used to construct three-dimensional (3D) trapped structures within an optical tweezers setup. In addition to being fully translatable in three dimensions, the trapped structure can be rotated controllably and continuously by introducing a frequency difference between the two laser beams. These interference patterns could play an important role in the creation of extended 3D crystalline structures.     

Carbon structures with three-dimensional periodicity at optical wavelengths

Porous carbons that are three-dimensionally periodic on the scale of optical wavelengths were made by a synthesis route resembling the geological formation of natural opal. Porous silica opal crystals were sintered to form an intersphere interface through which the silica was removed after infiltration with carbon or a carbon precursor. The resulting porous carbons had different structures depending on synthesis conditions. Both diamond and glassy carbon inverse opals resulted from volume filling. Graphite inverse opals, comprising 40-angstrom-thick layers of graphite sheets tiled on spherical surfaces, were produced by surface templating. The carbon inverse opals provide examples of both dielectric and metallic optical photonic crystals. They strongly diffract light and may provide a route toward photonic band-gap materials.     

Relating three-dimensional structures to protein networks provides evolutionary insights

Most studies of protein networks operate on a high level of abstraction, neglecting structural and chemical aspects of each interaction. Here, we characterize interactions by using atomic-resolution information from three-dimensional protein structures. We find that some previously recognized relationships between network topology and genomic features (e.g., hubs tending to be essential proteins) are actually more reflective of a structural quantity, the number of distinct binding interfaces. Subdividing hubs with respect to this quantity provides insight into their evolutionary rate and indicates that additional mechanisms of network growth are active in evolution (beyond effective preferential attachment through gene duplication).     

Templating three-dimensional self-assembled structures in bilayer block copolymer films

The registration and alignment of a monolayer of microdomains in a self-assembled block copolymer thin film can be controlled by chemical or physical templating methods. Although planar patterns are useful for nanoscale device fabrication, three-dimensional multilevel structures are required for some applications. We found that a bilayer film of a cylindrical-morphology block copolymer, templated by an array of posts functionalized with a brush attractive to the majority block, can form a rich variety of three-dimensional structures consisting of cylinder arrays with controllable angles, bends, and junctions whose geometry is controlled by the template periodicity and arrangement. This technique allows control of microdomain patterns and the ability to route and connect microdomains in specific directions.     

Selection for increased safety factors of biological structures as environmental unpredictability increases

Theory predicts that selection should increase the ratio of the performance of a biological structure or system to the requirements placed upon it (that is, its safety factor) as conditions become increasingly unpredictable. Although conventional safety factors are rarely measurable, an alternative, truncation safety factor (the ratio of mean strength to maximum possible load), can be measured quantitatively for certain load-bearing structures. For intertidal limpet shells subject to prying forces, truncation safety factor was found to increase with increased variability in shell strength, thus providing direct support for the theory.     

Tech.Sight. Phage display. Affinity selection from biological libraries

Phage display is a simple yet powerful technology that is used to rapidly characterize protein-protein interactions from amongst billions of candidates. This widely practiced technique is used to map antibody epitopes, create vaccines and to engineer peptides, antibodies and other proteins as both diagnostic tools and as human therapeutics. We overview the history of phage display and several recent applications.     

基于SNS 3维关系图生成方法探究

为了充分利用SNS理论设计关系网络并进行科学的管理,分析了目前使用的2维关系模型中存在的缺点,需要解决在同等关系的节点相对较多的情况下,位置冲突的问题。因此,本研究采用3维立体图形显示的方法,将关系节点的显示扩展到一个球面,有效的避免了节点冲突,并对3维立体图形的生成进行了分析、设计和通过创建Silverlight应用模拟实现关系节点间3维可视化显示。     

Imidodiphosphate and pyrophosphate: possible biological significance of similar structures

The structure of sodium imidodiphosphate has been determined by single crystal x-ray diffraction. The P-N-P bond angle (127.2 degrees) and P-N bond distance (1.68 angstroms) are remarkably similar to newly refined values for the P-O-P bond angle (128.6 degrees) and the bridging P-O bond distance (1.63 angstroms) of sodium pyrophosphate. This close similarity may explain why P-N-P linkages in algal "polyphosphates" escaped detection until recently and why adenosine triphosphate analogs with this linkage mimic adenosine triphosphate so closely.     

基于计算机视觉的苹果表面缺陷识别方法

在利用计算机视觉技术检测苹果外部品质的过程中,苹果表面缺陷的识别相对于形状、大小、颜色的检测要复杂得多,因此缺陷检测方法的研究极具挑战性。在实验的基础上,本文对几种缺陷检测算法(“洪水法”和“蛇形法”、“自适应球形变换法”、“参考图像法”、“标准球体灰度模型法”)的思路和实验结果进行了深入的分析和比较,并对缺陷检测中尚待解决的问题进行了阐述。     

渔船总布置图形符号图标菜单的设计开发

叙述了在Ａｕｔｏ ＣＡＤ１４环境下,渔船总布置图形符号库的建立以及图标菜单的设计思想。实践表明,开发出的图标菜单实用、有效。     

用割离井公式反求水文地质参数的直线图解法

在分析割离井法井流函数性质的基础上简化了井流函数,将雅各布直线图解法引入割离井法以反求水文地质参数,并进行了实例验证。结果发现,其步骤与常用的雅各布直线图解法步骤相似,计算结果十分接近。说明该方法是可行的。     

Leukotrienes and lipoxins: structures, biosynthesis, and biological effects

Arachidonic acid is released from membrane phospholipids upon cell stimulation (for example, by immune complexes and calcium ionophores) and converted to leukotrienes by a 5-lipoxygenase that also has leukotriene A4 synthetase activity. Leukotriene A4, an unstable epoxide, is hydrolyzed to leukotriene B4 or conjugated with glutathione to yield leukotriene C4 and its metabolites, leukotriene D4 and leukotriene E4. The leukotrienes participate in host defense reactions and pathophysiological conditions such as immediate hypersensitivity and inflammation. Recent studies also suggest a neuroendocrine role for leukotriene C4 in luteinizing hormone secretion. Lipoxins are formed by the action of 5- and 15-lipoxygenases on arachidonic acid. Lipoxin A causes contraction of guinea pig lung strips and dilation of the microvasculature. Both lipoxin A and B inhibit natural killer cell cytotoxicity. Thus, the multiple interaction of lipoxygenases generates compounds that can regulate specific cellular responses of importance in inflammation and immunity.