Quantum dots with phenylboronic acid tags for specific labeling of sialic acids on living cells

Sialic acids with a nine-carbon backbone are commonly found at the terminal position of the glycans structures on cell membranes. The unique distribution and ubiquitous existence of sialic acid on the cell membrane make them important mediators in various biological and pathological processes. We report a new class of imaging probes based on semiconductor quantum dots with small molecular phenylboronic acid tags for highly specific and efficient labeling of sialic acid on living cells. Our results have shown that the use of these probes enables one-step labeling and continuous tracking of the cell surface sialic acid moieties without any pretreatment of living cells. The one-step procedure with fast binding kinetics and the biocompatibility of these probes make it an ideal noninvasive technology for living cell imaging. We also find that the labeled sialic acids undergo quick internalization shortly after surface binding via endocytosis and eventually distribute in the perinuclear region. This distribution pattern is consistent with the notion that sialylated glycoproteins are populated on cell membranes and recycled through the vesicular exocytotic and endocytic pathways. The superior photostability and brightness of quantum dots enable quantitative analysis of the diffusion dynamics of sialic acids, which has been a significant challenge for glycan imaging.     

Photocatalytically Patterned TiO(2) Arrays for On-Plate Selective Enrichment of Phosphopeptides and Direct MALDI MS Analysis

We report the development of photocatalytically patterned TiO(2) arrays for selective on-plate enrichment and direct matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of phosphopeptides. A thin TiO(2) nanofilm with controlled porosity is prepared on gold-covered glass slides by a layer-by-layer (LbL) deposition/calcination process. The highly porous and rough nanostructure offers high surface area for selective binding of phosphorylated species. The patterned arrays are generated using an octadecyltrichlorosilane (OTS) coating in combination of UV irradiation with a photomask, followed by NaOH etching. The resulting hydrophilic TiO(2) spots are thus surrounded by a hydrophobic OTS layer, which can facilitate the enrichment of low-abundance components by confining a large volume sample into a small area. The TiO(2) arrays exhibit high specificity toward phosphopeptides in complex samples including phosphoprotein digests and human serum, and the detection can be made in the fmole range. Additional advantages of the arrays include excellent stability, reusability/reproducibility, and low cost. This method has been successfully applied to the analysis of phosphopeptides in nonfat milk. The patterned TiO(2) arrays provide an attractive interface for performing on-plate reactions, including selective capture of target species for MALDI-MS analysis, and can serve as a versatile lab-on-a-chip platform for high throughput analysis in phosphoproteome research.     

一种适用于四代机的多目标威胁评估算法

针对传统的空战多目标威胁评估不适于第四代战斗机超视距多目标空战威胁评估的问题, 提出了一种新的适合第四代战斗机超视距多目标空战的威胁评估方法。该方法在传统多目标威胁评估的基础上, 考虑空战高度和第四代战斗机隐身性能, 分别运用模糊优选法和区间层次分析(IAHP)法解算主客观权重, 进而得到综合权重区间, 并运用改进的TOPSIS法进行多目标威胁评估研究。仿真结果表明该算法的有效性和合理性, 适合于第四代战斗机超视距多目标空战的威胁评估。     

互动电视发展前景及有线电视网络的利用

本文阐述了互动电视的概念及其发展前景以及如何利用有线电视网发展互动电视业务。     

硫化态加氢精制催化剂的Mo和NiK边XAFS研究

1. Introduction Hydroprocessing catalysts based upon the transitionmetal sulfides (TMS) have been widely used for about70 years. In the early period, some metal compoundssuch as Co, Ni, Mo and W sulfides and their mixtureswere believed to be the most a…     

一种新的SOI射频集成电路结构与工艺

立足于与常规CMOS兼容的SOI工艺，提出了电子束／I线混合光刻制造SOI射频集成电路的集成结构和工艺方案。该方案只使用9块掩模版即完成了LDMOS、NMOS、电感、电容和电阻等元件的集成。经过对LDMOS、NMOS的工艺、器件的数值模拟和体硅衬底电感的初步实验，获得了良好的有源和无源器件特性，证明这一简洁的集成工艺方案是可行的。     

应变SiGe沟道pMOSFET的击穿特性

以半导体器件二维数值模拟程序Medici为工具,模拟和对比了SiGepMOS同SipMOS的漏结击穿电压随栅极偏压、栅氧化层厚度和衬底浓度的变化关系;研究了SiGepMOS垂直层结构参数硅帽层厚度、SiGe层厚度及Ge剂量和p+ δ掺杂对于击穿特性的影响.发现SiGepMOS击穿主要由窄带隙的应变SiGe层决定,击穿电压明显低于SipMOS并随Ge组分增加而降低;SiGe/Si异质结对电场分布产生显著影响,同SipMOS相比电场和碰撞电离具有多峰值分布的特点;Si帽层及SiGe层参数对击穿特性有明显影响,增加p型δ掺杂后SiGepMOS呈现穿通击穿机制     

苏北盆地MQ油田低阻油层识别标准研究

MQ油田低阻油层主要是因为该区储层夹有薄泥岩层，导致油层电阻率偏低，常规测井解释很难将油层、水层和干层区分开，针对这种现象，采用先进的软件包，利用多方程和多参数综合解释新技术，很好地分清油水层，找到了识别低电阻率油层的有效方法，确定了该油田油层、水层和干层的识别标准。     

半导体断路开关(SOS)特性研究

本文描述了半导体断路开关(SOS)的制作及性能测试。制作方法采用普通二极管类似的扩散工艺．但其制作工艺的关键在于深结的扩散。在pn结足够深时才能产生SOS效应。描述了制作过程并采用脉冲电路测试了所研制的SOS器件的电学性能。测试结果表明所研制的样品性能达到了与国外水平。