In vitro study of the early membrane effects of C27-steroid hormone ecdysterone, immobilized on the nanodispersed magnetite surface]

The object of the study was to reveal the existence of receptor interactions of C27-steroid hormone ecdysterone with the surface of various cells (liver and spleen macrophages, thymus and spleen lymphocytes, erythrocytes and hepatocytes from rat organs) in experiments in vitro using ecdysterone immobilized on the nanodispersed iron surface (which did not penetrate the cell during observation) and the model of fast (during 15 s) activation of phospholipid signal system with ecdysterone. The parameters, which are characteristic of cell phospholipid signal system activation, were evaluated (the concentrations of free arachidonic acid, diene conjugates, tromboxane B2 and leukotriene C4) and its alteration in response to free and immobilized ecdysterone introduction in suspensins of intact cells and cells with the surface modified in vivo by pre-injection of antigen (human erythrocytes). Concurrent binding of immbilized ecdysterone with intact rat cells in the presence of free ecdysterone was also investigated. It was established that there are high-affinity ecdysterone-specific binding sites on the plasma membranes of all cells investigated, Kd estimated according to two different methods varied in the region of 10(-8)-10(-7) M. The characteristic features of the changes in parameters characteristic of phospholipid system activation were revealed to be queite similar in intact cells, as well as in cells with modified surfaces, under introduction of free ecdysterone and immobilized ecdysterone, which did not penetrate into cytosole. The data obtained point to the existence of ecdysterone receptors on the surface of cells plasma membranes and are indicative of the membrane effects as mechanisms of the early pregenomic phase of cells activation by ecdysterone.     

φ1200×1500齿辊破碎机的设计与改进

简要介绍齿辊破碎机的工作原理、结构特点 ,分析生产应用中存在的问题 ,进行优化设计 ,提高了破碎效率。     

基于定子电流Park矢量变换的感应电机故障诊断

通过提取定子电流信号Park矢量图作为电机故障特征，应用人工神经网络技术对故障特征进行分类与识别，从而避开复杂的谱分析技术，实验测试结果表明，该方法用于电机故障诊断可靠、有效，是一种实际可行的电机故障诊断方法。     

军事通信网可靠性研究进展与系统的分析评估

本文通过对国内外军事通信网可靠性研究的综合,归纳出表征通信网可靠性的四类指标参数,尽而提出通信网可靠性分析评估的方法与途径。     

数字通信技术的发展

现代通信的数字化技术,如信源量化、信道编码、载波调制和数字网控,不仅为军事通信提供了高效、可靠、保密的通信手段,也为信息社会提供了大容量、高速率、多媒介的通信手段。本文即介绍以上内容。     

The "interleukin 1 receptor antagonist" is a partial agonist of prostaglandin synthesis by human decidual cells

In many systems the interleukin-1 receptor antagonist opposes the effects of interleukin-1 beta. We considered that it might block interleukin-1 beta-stimulated prostaglandin production from human decidual cells. Very high levels of interleukin-1 receptor antagonist (> 1000 pg/ml) had limited inhibitory effects on IL-1 beta-stimulated PGE2 synthesis, and lower levels of antagonist (< 1000 pg/ml) increased the effects of IL-1 beta. Low concentrations of the antagonist alone (1-100 pg/ml) increased basal PGE2 production, whereas higher levels (10-100 ng/ml) had less effect. It seems, therefore, that in human decidua the "antagonist" is more accurately described as a partial agonist. It has been suggested that the IL-1 receptor antagonist could be used to inhibit decidual prostaglandin synthesis and thereby prevent preterm labor, but this report shows that caution should be exercised before using the receptor antagonist.     

BEHAVIOUR OF FLUORINE IN BLAST-FURNACE SMELTING Ⅴ. AN INVESTIGATION OF THE SLAG-FORMING PROCESSES IN A 11M~3 BLASTFURNACE SMELTING PAO-TOU IRON ORE

在本文中,我们报告了11M~3高炉冶炼包头铁矿时炉料样品包括矿石、初渣、终渣的岩相分析及初渣的化学分析结果,并结合温度测定数据,画出了高炉中等温线及各区域的分市情况,以及各区域炉料中的矿物组成。根据以上实验结果,讨论了冶炼包头铁矿时的初渣形成机理,并指出初渣的性质与一般酸性铁矿不同,此点对高炉的顺行有利。     

0412-1961

本文提出在非晶态合金的形成中,元素的原子半径采用实测的原子间距之半来衡量。在总结归纳大量实验资料的基础上发现二元或多元非晶态合金,其组成元素的尺寸因素(ΔR/R_i)都大于9％(个别例外)。分析了影响形成二元非晶态合金的因素,得到了形成二元非晶态合金的必要条件为: