食饵具有Smith增长且基于比率依赖捕食系统模型的定性分析

研究一类食饵为Smith增长且基于比率依赖的HollingⅢ型功能反应捕食系统模型,运用示性方程讨论参数变化时奇点(0,0)邻域内轨线的走向,给出系统平衡点为全局吸引子或吸引子的充分条件,得到系统正周期解的不存在性、正平衡点的全局渐近稳定性及系统存在极限环的充分条件.     

脉冲微分方程正周期解的存在唯一性与全局吸引性（英文）

本文,我们考虑了脉冲微分方程.正周期解的存在唯一性与全局吸引性,通过使用不动点定理,建立了该方程唯一正周期解的存在性与全局吸引性的充分条件.特别地,我们给出x是其他正解的全局吸引子.我们的结果推广和改进了已有文献结果.     

变系数变时滞BAM神经网络概周期解的存在性与全局吸引性

利用指数二分性、Banach不动点定理与微分不等式分析技巧,在不要求激活函数有界的条件下,给出了变系数变时滞的BAM神经网络概周期解的存在唯一性和全局吸引性的充分条件．所得结果推广和改进了相应文献的结果。对设计BAM神经网络概周期振荡有重要意义．     

双营养Chemostat模型周期解的全局吸引性

研究含有时滞的双营养单种群Ｃｈｅｍｏｓｔａｔ模型周期解的全局吸引性,首先利用强正、凹算子理论给出了系统存在唯一正周期解的充分条件,然后利用泛函微分方程的单调理论得到了正周期解的全局吸引性。     

具有时滞的北美鹑增长模型的振动性和全局吸引性

本文研究了离散Ｂｏｂｗｈｉｔｅ Ｑｕａｉｌ模型的振动性和全局吸引性．获得了该方程的一切解关于正平衡常数Ｎ＝振动的充分条件以及其所有正解趋近于正平衡常数Ｎ的充分条件．     

n种群Lotka-Volterra周期系数捕食-竞争系统周期解的存在性与全局吸引性

在本文中,作者考察了n种群Lotak-Volterra周期捕食-竟争系统,用比较定理、Brouwer不定点定理和V函数方法证明了正解的最终有界性、正周期解的存在性、正周期解的全局吸引性及唯一性．     

一类时滞捕食-食饵系统的概周期解的存在唯一性和全局吸引性

利用微分不等式及Liapunov泛函,研究了一类具有时滞和Modified Leslie-Gower HollingⅡ功能性反应捕食-食饵系统,获得了系统一致持久及解全局吸引的充分条件,对于这类概周期系统,建立了存在全局吸引的唯一正概周期解的准则.     

随机配对种群的两性模型的动力学性态

基于Kendall-Goodman模型，提出了一个两性具有不同生理性态的随机配对的两性模型．如果不考虑密度制约因素，那么模型存在一个全局渐近稳定的指数解；如果考虑密度制约因素，对于给定的一个出生函数，得到了唯一正平衡态存在及全局稳定的充要条件．结论表明，无论是否考虑密度制约因素，种群的性比总是稳定的．     

带偏差变元的时滞微分模型的全局吸引性

本文考虑带偏差变元的红血球生存模型获得了其正平衡N~*是全局吸引子的充分条件，它推广和改进了文献〔2〕，〔3〕和〔4〕的结果．     

一类Nicholson's blowflies模型的全局吸引性和振动性

本文研究了带有多个滞后变量的Ｎｉｃｈｏｌｓｏｎ’ｓ ｂｌｏｗｆｌｉｅｓ动态模型Ｎ（ｔ）＝－δＮ（ｔ）＋ΣＰｉＮ（ｔ-τｉ）ｅ-ａｉＮ（ｔ-τｉ）的全局吸引性和振动性,获得了该方程的正平衡解为全局稳定的充分条件以及其所有正解关于该平衡解振动的充分条件．     

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。     

Engineered Molecular Therapeutics Targeting Fibrin and the Coagulation System: a Biophysical Perspective

The coagulation cascade represents a sophisticated and highly choreographed series of molecular events taking place in the blood with important clinical implications. One key player in coagulation is fibrinogen, a highly abundant soluble blood protein that is processed by thrombin proteases at wound sites, triggering self-assembly of an insoluble protein hydrogel known as a fibrin clot. By forming the key protein component of blood clots, fibrin acts as a structural biomaterial with biophysical properties well suited to its role inhibiting fluid flow and maintaining hemostasis. Based on its clinical importance, fibrin is being investigated as a potentially valuable molecular target in the development of coagulation therapies. In this topical review, we summarize our current understanding of the coagulation cascade from a molecular, structural and biophysical perspective. We highlight single-molecule studies on proteins involved in blood coagulation and report on the current state of the art in directed evolution and molecular engineering of fibrin-targeted proteins and polymers for modulating coagulation. This biophysical overview will help acclimatize newcomers to the field and catalyze interdisciplinary work in biomolecular engineering toward the development of new therapies targeting fibrin and the coagulation system.     

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.     

The kinin–kallikrein system: physiological roles,pathophysiology and its relationship to cancer biomarkers

Abstract

The kinin–kallikrein system (KKS) is an endogenous multiprotein cascade, the activation of which leads to triggering of the intrinsic coagulation pathway and enzymatic hydrolysis of kininogens with the consequent release of bradykinin-related peptides. This system plays a crucial role in inflammation, vasodilation, smooth muscle contraction, cardioprotection, vascular permeability, blood pressure control, coagulation and pain. In this review, we will outline the physiology and pathophysiology of the KKS and also highlight the association of this system with carcinogenesis and cancer progression.     

The mechanisms and kinetics of initiation of blood coagulation by the extrinsic tenase complex

Biophysics - The system of hemostasis includes coagulation of blood plasma and formation of platelet aggregate. Plasma clotting is a cascade of proteolytic reactions, triggered by the contact of...     

Proteomic analysis of the coagulation reaction in plasma and whole blood using PROTOMAP

Proteases are critical in many physiological processes and the human genome encodes for 566 predicted proteolytic enzymes. Therefore, there is great interest in identifying and characterizing physiologic protease-substrate relationships. The coagulation cascade is a well-described network of serine proteases. However, new interactions of the coagulation cascade with other biological pathways have been discovered only recently. Therefore, we hypothesized that a non-biased protease degradomics analysis of the physiologic coagulation reaction would identify new interactions between the coagulation cascade and other pathways. We used the recently described PROTOMAP technique to profile the complete coagulation degradome. This analysis detected virtually all of the proteins of the coagulation cascade and identified a majority of the expected proteolytic events, suggesting significant coverage of the coagulation degradome. Multiple potential new proteolytic cleavages were detected, including two of transmembrane proteins that may be shed from the surface of blood cells. In addition, this analysis was able to identify several new potentially secreted proteins. A significant majority of the newly identified events were of proteins involved in innate immunity (complement and inflammation). This highlights potential new areas of crosstalk between these linked systems. Future studies will elucidate the details and functional consequences of these proteolytic events during coagulation.     

Crustacean Immunity and Complement; a Premature Comparison?

SYNOPSIS. The prophenoloxidase activating system constitutesa system for recognition of foreignness in several invertebrates.The system has been especially well studied in crustaceans andit will now be possible to begin structural comparisons betweencomponents of the prophenoloxidase activating system and componentsof other cascade systems which function in host defense suchas the vertebrate complement and blood coagulation.     

Structural basis of membrane binding by Gla domains of vitamin K-dependent proteins

In a calcium-dependent interaction critical for blood coagulation, vitamin K-dependent blood coagulation proteins bind cell membranes containing phosphatidylserine via gamma-carboxyglutamic acid-rich (Gla) domains. Gla domain-mediated protein-membrane interaction is required for generation of thrombin, the terminal enzyme in the coagulation cascade, on a physiologic time scale. We determined by X-ray crystallography and NMR spectroscopy the lysophosphatidylserine-binding site in the bovine prothrombin Gla domain. The serine head group binds Gla domain-bound calcium ions and Gla residues 17 and 21, fixed elements of the Gla domain fold, predicting the structural basis for phosphatidylserine specificity among Gla domains. Gla domains provide a unique mechanism for protein-phospholipid membrane interaction. Increasingly Gla domains are being identified in proteins unrelated to blood coagulation. Thus, this membrane-binding mechanism may be important in other physiologic processes.     

Rheological study on coagulation of blood with special reference to the triggering mechanism of venous thrombus formation

A markedly reduced blood flow, an elevation of hematocrit and an increased aggregability of erythrocytes [red blood cells (RBCs)] are risk factors for venous thrombus formation (intravascular blood coagulation). However, these risk factors alone seem to be insufficient to stimulate the coagulation cascade in the absence of a primary triggering mechanism. In this paper, our rheological and biochemical studies on blood coagulation, especially focusing on procoagulant activity of RBCs, are summarized. It is shown that the intrinsic coagulation pathway is triggered by the activation of factor IX (F-IX) by RBCs. The F-IX-activating enzyme in normal human erythrocyte (RBC) membranes was purified, identified and characterized. The activation of F-IX by RBCs was enhanced by a decrease in flow shear rate and an elevation in hematocrit. The procoagulant ability of RBCs and coagulation of blood obtained from individuals with a relatively high level of hypercoagulability were enhanced compared with those for normals. The studies demonstrated a new triggering mechanism for coagulation or thrombus formation that may occur under stagnant flow conditions.