The LDL receptor pathway delivers arachidonic acid for eicosanoid formation in cells stimulated by platelet-derived growth factor

Animal cells can convert 20-carbon polyunsaturated fatty acids into prostaglandins (PGs) and leukotrienes. These locally produced mediators of inflammatory and immunological reactions act in an autocrine or paracrine fashion. Arachidonic acid (AA), the precursor of most PGs and leukotrienes, is present in the form of lipid esters within plasma lipoproteins and cannot be synthesised de novo by animal cells. Therefore, AA or its plant-derived precursor, linoleic acid, must be provided to cells if PGs or leukotrienes are to be formed. Because several classes of lipoproteins, including low-density lipoproteins (LDL), very-low-density lipoproteins, and chylomicron remnants, are taken up by means of the LDL receptor, and because LDL and very-low-density lipoproteins, but not high-density lipoproteins, stimulate PG synthesis, we have suggested previously that PG formation is directly linked to the LDL pathway. Using fibroblasts with the receptor-negative phenotype of familial hypercholesterolaemia and anti-LDL receptor antibodies, we show here that LDL deliver AA for PG production and that an LDL receptor-dependent feedback mechanism inhibits the activity of PGH synthase, the rate-limiting enzyme of PG synthesis. These results indicate that the LDL pathway has a regulatory role in PG synthesis, in addition to its well-known role in the maintenance of cellular cholesterol homeostasis.     

感应电机定子磁通定向（SFO）控制中的死区效应分析

对感应电机定子磁通定向控制中的死区效应进行了分析与讨论，从理论上阐明了死区的存在及其对系统性能的影响。经过数学分析与理论推导，得出了死区效应对系统在低速轻载时的影响尤为显著的结论，为工程实际提供了理论依据和方法。     

钢丝绳检验数据的参变量磨光样条插值法

利用参变量磨光样条降维方法，对钢丝绳检验数据插值，内插可以估计因缺少钢丝绳检验造成的数据损失，外推可以对钢丝绳检验数据趋势进行预测，为钢丝绳故障诊断仪在线估计钢丝绳剩余强度和剩余寿命提供理论和方法．     

地图数据库语言MQL的设计与实现

提出一种新型的地图数据库语言ＭＱＬ，它是传统的标准ＳＱＬ语言的扩充．讨论了ＭＱＬ的设计思想、功能特色与使用方式．该语言现已成功地应用到地图数据库管理系统ＭＤＢ中     

模糊关系的不动点及在计算传递闭包中的应用

给出了模糊关系的不动点定义，以及找不动点的一些方法，阐述了不动点通路的性质。利用不动点及不动点通路的性质，改进了模糊关系传递闭包的计算方法。     

非晶硅色敏元件表色系统分区域空间线性变换研究

提出了表色系统分区域空间线性变换的原则，用软件技术解决非晶硅色敏元件光谱曲线与ＣＩＥ标准色度观察者光谱三刺激值曲线的拟合问题，简化了仪表的光学结构。     

光度法研究海藻酸铁（Ⅲ）与抗坏血酸反应动力学

用光度法研究由部分水解的海藻酸钠合成的海藻酸铁（Ⅲ）配合物与抗坏血酸氧化还原反应的速度方程，分析海藻酸钠水解程度与海藻酸铁在反应中行为的关系；并依据实验结果和简单铁（Ⅲ）配合物与抗坏血酸的反应机理推测海藻酸铁与抗坏血酸的反应机理，推测海藻酸铁的可能结构。     

一种多媒体数据库存储系统的实现方法

探讨了多媒体数据存储管理实现技术，给出了实际采用的基于关系模型扩充的“层双关系”数据模型和实现常规数据与多媒体数据一体比存储管理的一种方法。