一类捕食-食饵系统的定性分析

本文用定性分析的方法研究了一类捕食-食饵系统的全局性质,给出了该系统不存在极限环以及存在唯一稳定极限环的条件．     

一类生化系统的稳定性

本文研究一类生化系统的极限环的存在性与唯一性;分析了系统轨线的全局结构,指出了系统在无穷远点处的轨线存在奇异方向;解释了极限环消失的原因．     

一个生物化学反应模型的定性分析

本文对生物化学反应模型．其中A＞0,B＞0,进行了定性分析,结果是：系统的一切正初值的正半轨线有界;当B＜AB 1时系统不存在极限环;当B＞AB＋1时,系统存在唯一稳定的极限环．从而改进了文〔2〕的结论．     

一类三次Kolmogorov系统极限环的存在性和唯一性

研究一类三次Ｋｏｌｍｏｇｏｒｏｖ系统,获得了系统存在极限环和存在唯一极限环以及不存在极限环的条件。     

具功能性反应函数kxθ的捕-食系统极限环的存在唯一性

研究了捕食者无密度制约,食饵具有功能性反函数kx~θ(0＜θ≤1)的捕-食系统的定性行为．在食饵有(或无)常数放养率的情况下,利用Pioncare-Bendixsion环域定理,极限环的存在唯一性定理及旋转向量场理论,对此系统作了完整的定性分析,得到了该系统全局渐近稳定和存在唯一稳定极限环的充分条件．     

具有变消耗率微生物连续培养模型的定性分析

研究了一类具有变消耗率的微生物连续培养系统,当消耗率是线性函数时得到了正平衡点全局渐近稳定的充要条件,当消耗率是二次函数时得到了系统存在极限环的充分条件,同时利用分支理论研究系统存在Hopf分支的条件,判定了极限环的稳定性．     

一类平面三次系统极限环存在唯一性系数判据

给出了利用平面三次系统的系数来判断该系统极限环存在唯一性的系数判据．     

一类食饵种群具有常数存放率的Kolmogorov系统的定性分析

本文对一类食饵种群具有常数存放率的Kolmogorov系统进行了定性分析,研究了系统平衡点的性态,证明了极限环的存在和唯一性．     

一个食饵种群具有常数收获率和具有第Ⅲ类功能性反应的捕-食系统的定性分析

本文对一个食饵种群具有常数收获率的和具有第Ⅲ类功能性反应的捕食系统作了较完整的定性分析,讨论了分界线的相对位置和分界线环的存在性、稳定性,得到了极限环存在性和唯一性的条件．     

一类具有稀疏效应的生态系统的极限环

研究如下一类具有稀疏效应的生态系统模型应用微分方程定性理论,得到了该系统极限环的存在性、唯一性及存在性的参数范围．     

凝血瀑布机制的序结构分析方法

凝血系统的瀑布机制揭示了凝血因子间的酶促级联反应过程。在级联反应中,各个因子间明显地存在着序关系,而这种序关系的全体构成了系统的序结构。从系统论的观点看,系统的结构是系统性质与功能的基础,因此,通过模型化方法以及利用凝血因子序结构图建立的序结构分析方法,是分析凝血系统各因子相互作用的有用的工具。对蛋白Ｃ及ＴＦＰＩ进行序结构分析,进一步阐明了这两种抑制剂对外源途径凝血的作用特点。     

外源途径凝血的抑制作用的模型与模拟(二)──TFPI的动力学影响

动力学模型化方法在凝血系统的研究中已经取得了丰硕的成果,文章将这一方法用于分析组织因子途径抑制剂对凝血系统的影响,得到的结论揭示了凝血过程是振荡的时间过程,并且它存在着多种稳定的终态。特别是稳定的周期振荡终态的存在在血液学研究中是一个十分有趣而重要的现象。同时由于主要结果与实验及临床相吻合,展示出模型化方法及数值模拟方法在凝血问题研究中的重要作用。     

外源性凝血瀑布动力系统的稳定性

本文首先建立了相应于Lamula与Griffin的凝血动力系统瀑布模式的非线性数学模型．并使用分叉方法较深入地分析了该系统的定态平衡解与动态解的稳定性与全局吸引子．通过动力学分析,我们从理论上证明了存在外源性路径启动的触发阈值及瀑布机制达到终态的细节：趋于一个全局吸引子．     

对"功能反应函数为x的食饵——捕食系统的定性分析"一文的注记

重新分析了文[1]所讨论过的功能反应函数为x的捕食系统(1),分析了此系统在第一象限内轨线的拓朴结构,证明了系统(1)的唯一正平衡点如果不稳定,则存在唯一(稳定)极限环;如果稳定,则全局稳定于此正平衡点,纠正了文[1]中关于系统(1)极限环的存在性、稳定性等方面的一些结论.     

对“功能反应函数为x~(1/2)的食饵-捕食系统的定性分析”一文的注记

重新分析了文［１］所讨论过的功能反应函数为ｘ~（１／２）的捕食系统（１）,分析了此系统在第一象限内轨线的拓朴结构,证明了系统（１）的唯一正平衡点如果不稳定,则存在唯一（稳定）极限环;如果稳定,则全局稳定于此正平衡点,纠正了文［１］中关于系统（１）极限环的存在性、稳定性等方面的一些结论．     

Circannual changes in blood coagulation factors and the effect of warfarin on the hedgehog Erinaceus europaeus

Levels of blood coagulation factors were measured monthly in hedgehogs kept at 20 degrees C under a natural-light schedule for 1 yr using prothrombin time and the P & P method. Hedgehogs display a circannual cycle of blood coagulation factors in the absence of temperature cues, with high levels corresponding to the active period and low levels corresponding to the hibernation period. Ten hedgehogs and ten guinea pigs were treated with clinical doses of warfarin and blood coagulation factors measured. Warfarin caused a similar decrease in vitamin K-dependent blood coagulation factors in both species.     

Fibrin membrane endowed with biological function VI. Immobilization of multienzymes of urea cycle

Four enzymes in urea cycle and inorganic pyrophosphatase were immobilized simultaneously into a matrix of fibrin fiber formed from fibrinogen by the concerted action of thrombin and blood coagulation Factor XIII. The immobilized multienzyme system not only had an ability to carry out urea cycle continuously at least over several hours, but also had a greatly improved efficiency over the corresponding soluble system.     

Separation between the alpha and beta forms of human antithrombin by hydroxyapatite high-performance liquid chromatography

Human antithrombin (AT) inhibits several proteases in the coagulation system, including thrombin and factor Xa, and thus, plays an important role in the regulation of blood coagulation. The predominant form of AT in plasma is ATalpha, which contains four glycosylated asparagine residues, and the minor form is ATbeta, which lacks the Asn-135 glycosylation. In this study, hydroxyapatite high-performance liquid chromatography, using a segmented sodium phosphate gradient, was utilized for the high-resolution separation of ATalpha and ATbeta. The detection limit (signal-to-noise ratio of 3) for ATbeta was 30 microg/mL, corresponding to 0.5% of the injected concentration of AT. Two analyzed commercial AT products both contained about 2% ATbeta. This method is suitable for the determination of ATbeta in pure samples of native AT.     

Coagulation signalling following tissue injury: focus on the role of factor Xa

The primary function of the coagulation cascade is to promote haemostasis and limit blood loss in response to tissue injury. However, it is now recognized that the physiological functions of the coagulation cascade extend beyond blood coagulation and that this cascade plays a pivotal role in influencing inflammatory and tissue repair responses via the activation of their signalling responses, the proteinase-activated receptors (PARs). Consequently, uncontrolled coagulation activity and PAR signalling contributes to the pathophysiology of several conditions, including thrombosis, arthritis, cancer, kidney disease, and acute and chronic lung injury. Much of the work thus far has focused on the role of thrombin-mediated signalling in the pathophysiology of these conditions. However, recent evidence suggests that coagulation proteinases upstream of thrombin, including factor Xa (FXa), may also signal via PARs and thus induce cellular effects independent of thrombin generation. These studies have highlighted a novel and important role for FXa signalling in influencing proinflammatory and pro-fibrotic effects following tissue injury. This article will provide an overview of FXa as a central proteinase of the coagulation cascade and will review more recent evidence that FXa signalling may contribute to inflammation and tissue remodelling. The novel opportunities that this may present for therapeutic intervention will also be highlighted.