Development of specific suppressor cells in hypoinsulinaemic mice

Mice and rats injected with alloxan or streptozotocin develop permanent diabetes, characterised by deficient insulin production. It has been demonstrated that hypoinsulinaemia in mice leads to significant loss of lymphatic tissue, and these diabetic animals cannot develop contact sensitivity or efficient graft rejection. Administration of insulin partially restored these responses and also caused an increase in the weight of the thymus and spleen. Similar suppression of T cell-dependent phenomena has been observed in surgically pancreatectomised rats. Lymphocytes of these hypoinsulinaemic animals show significantly decreased in vitro responses to plant lectins and generate only low levels of cytotoxic effector cells. We previously showed that cells of normoglycaemic oxazolone-sensitised mice cannot transfer significant contact sensitivity reactions into diabetic recipients indicating that the milieu of hyperglycaemic insulin deficient animals cannot support all the activity of immune T cells. By mixing immunised T cells from control and diabetic mice and transferring the mixtures into normal recipients we now show that the non-supportive millieu in diabetic animals may be due to active suppression rather than to athrepsis.     

一般约束最优化强收敛的广义强次可行方向法

讨论一般约束最优化,利用广义投影技术和强次可行方向法思想,建立一个初始点任意的新算法,该算法不仅具有全局收敛性,而且是强收敛的,文中还对算法进行数值试验。     

A suppressor T-lymphocyte cell line for autoimmune encephalomyelitis

Experimental allergic encephalomyelitis (EAE) is a model for the in vitro and in vivo study of T-cell activation. It is an autoimmune disease mediated by T lymphocytes of the helper T-cell (Th) subset. After sensitization to guinea-pig myelin basic protein in complete Freund's adjuvant, Lewis rats develop an autoimmune response to central nervous system (CNS) myelin basic protein, manifested clinically as paralysis and histologically by a perivascular mononuclear cell infiltrate of the CNS parenchyma. Suppressor cell regulation of EAE has long been suspected because Lewis rats, which spontaneously recover from active disease, are resistant to reinduction of active EAE, even though effector T-cell lines can be rescued from these recovered rats. Using cyclosporin A, an immunosuppressive agent believed to inhibit Th cell function, suppressor T-cell (Ts) lines have now been generated from recovered Lewis rats. These Ts cells, when admixed with guinea pig myelin basic protein-specific Th cells, will prevent the adoptive transfer of EAE. The Ts cells appear to be CD4+, which explains previous observations that CD8+ lymphocytes are not important in the recovery of EAE in the rat. This is the first direct demonstration of Ts-cell regulation of EAE.     

一种新型萃取柱的制备及在盐酸克伦特罗富集中的应用研究

利用3-磺酸丙基甲基丙烯酸酯钾盐为单体,乙二醇二甲基丙烯酸酯为交联剂,正丙醇、1,4-丁二醇和水为三元致孔剂,通过在装满硅球的250μm内径的石英毛细管内原位聚合制备了1种强阳离子交换有机聚合物包覆硅球整体柱.通过对单体总浓度、聚合反应温度和聚合反应时间的调节来控制有机聚合物对硅球的包覆,确定了整体柱的最佳制备条件.最佳条件:单体总浓度T=30%,C=50%;反应温度60℃;反应时间3h.在优化了影响萃取效率的参数(洗脱液组成,萃取柱的吸附容量,进样速度,样品的pH)后,测得该整体柱对盐酸克伦特罗的富集倍率高达535.     

一种强阳离子交换液相色谱整体微柱

利用3-磺酸丙基甲基丙烯酸酯钾盐为单体,乙二醇二甲基丙烯酸酯为交联剂,正丙醇、1,4-丁二醇和水为三元致孔剂,原位聚合制备了一种强阳离子交换整体柱,确定了柱的最佳制备条件;制得的整体柱的色谱性能通过对常见无机阳离子混合物的分离进行了评价,结果表明直接共聚法比后化学修饰法制备的离子交换整体柱具备更高的分离效能;通过考察流动相pH值及其组成对色谱保留行为的影响,证实了胺类化合物在该柱上的保留机理为离子交换与疏水作用的共同作用.     

关于NA序列的强大数定律

NA随机变量是一包含独立随机变量在内的有广泛应用的随机变量类,文章在一类宽泛条件下研究了不同分布NA序列的强大数定律,改进和推广了前人的相应结果.     

In vitro suppression of UGA codons in a mitochondrial mRNA

Although both prokaryotic and eukaryotic messenger RNAs can be easily translated in heterologous protein-synthesizing systems, attempts to achieve correct synthesis of mitochondrial proteins by translation of mitochondrial mRNAs in such systems have failed. In general, the products of synthesis are of low molecular weight and presumably represent fragments of mitochondrial proteins. These fragments display a strong tendency to aggregate. Explanations have included the use by mitochondria of codons requiring a specialized tRNA population and the fortuitous occurrence within genes of purine-rich sequences resembling bacterial ribosome binding sites. In addition, the long 5'-leader sequences present in many mitochondrial (mt) RNAs may also contribute to difficulties in mRNA recognition by heterologous ribosomes. Recent sequence analysis of human mtDNA suggests that the genetic code used by mammalian mitochondria deviates in a number of respects from the 'universal' code, the most striking of these being the use of the UGA termination codon to specify tryptophan. That this may also apply in yeast mitochondria has been shown by Fox and Macino et al., thus providing an obvious and easily testable explanation for the inability of heterologous systems to synthesize full-length mitochondrial proteins. We confirm this explanation and describe here the in vitro synthesis of a full-length subunit II of yeast cytochrome c oxidase in a wheat-germ extract supplemented with a partially purified mitochondrial mRNA for this protein and a UGA-suppressor tRNA from Schizosaccharomyces pombe.     

求解强稳定化问题的一种新方法

主要考虑了套代数框架下时变线性系统的强稳定化问题.对于给定的离散线性时变系统,即系统是下三角的无穷维矩阵,借助双互素因子分解,给出了系统可强稳定化的一个新的充要条件.特别是该充要条件对线性时不变系统的强稳定化也是成立的.     

存储特定流数据的通用框架

通过仔细研究存储流数据的各种应用的共同特征,提出了一种数据流存储模型.在数据流存储模型基础上,采用先进的基于组件的开发方法,实现了一个存储流数据的通用框架,通用框架采用本体技术来解决语义互操作性.测试结果表明,通用框架可以调用一组用户提供的过滤算法,筛选出指定数据流中符合条件的信息,将它们成批存储到数据库中.用户可以通过定制和配置参数的方法,在各种不同的应用环境中重用该通用框架.     

一族非扩张非自映射的强收敛性定理

建立了一种新的迭代序列,利用此序列逼近非扩张非自映射族的公共不动点,获得了一些强(弱)收敛定理.所得定理改进和推广了现有文献的一些相应结果.     

一种适于强横向变速的高阶差分正演模拟方法

波动方程正演模拟法相对于射线法具有精度高、效率低的特点。为了提高其效率，提出了一种高阶差分正演模拟方法。该方法考虑了速度场局部的强横向变化，适于复杂介质的正演模拟；在相同精度下，高阶差分的空间横向间隔可取为低阶差分的2-4倍，有较高的计算效率；高阶差分加上合适的边界条件能较好地解决网格频散和边界效应问题。通过对Marmousi模型的试算，验证了该方法对复杂速度模型的适应性、有效性和实用性。     

一种适于强横向变速的高阶差分正演模拟方法

波动方程正演模拟法相对于射线法具有精度高、效率低的特点。为了提高其效率 ,提出了一种高阶差分正演模拟方法。该方法考虑了速度场局部的强横向变化 ,适于复杂介质的正演模拟 ;在相同精度下 ,高阶差分的空间横向间隔可取为低阶差分的 2～ 4倍 ,有较高的计算效率 ;高阶差分加上合适的边界条件能较好地解决网格频散和边界效应问题。通过对Marmousi模型的试算 ,验证了该方法对复杂速度模型的适应性、有效性和实用性。     

关于离散随机变量序列的一类强偏差定理

引入极限相对对数似然比的概念,作为离散相依随机变量序列与独立随机变量序列的偏差的一种度量,并利用它来研究离散相依随机变量序列的极限性质．引入一种全新的概率研究方法——分析法,得到了一类用不等式表示的强极限定理,即强偏差定理,其偏差界依赖于此极限相对对数似然比．作为推论得到了经典的独立随机变量序列的强大数定理,进一步发展和完善了状态空间离散有限的随机变量序列关于乘积分布的强偏差定理．     

一种大概率强连通鲁棒性的无线传感器网络构造算法

针对无线传感器网络的软硬件必须具备鲁棒性、抗毁性和容错性的特点提出了一个具有大概率强连通鲁棒性的无线传感器网络构造算法并进行了仿真分析.该构造算法不仅具备WSN所要求的鲁棒性、抗毁性,而且也兼顾到传感器节点能量保护和网络功率控制.     

任意随机变量序列强极限定理的一个推广

利用随机变量的截尾方法和Doob鞅收敛定理，研究了任意随机变量序列的性质，得到了一类矩条件下任意随机变量序列的强极限定理，推广了与此相应的一些结果．