427 research outputs found
HYBRID TOPOLOGY DESIGN USING ARTIFICIAL INTELLIGENCE TECHNOLOGY
When composing computer aided design algorithms, it often proves useful to examine the following problems: how does the human designer plan and how does he handle parallelism and foresight. If we want to create a model of human designer planning methodology, we can use the artificial intelligence technology. In this paper we illustrate our approach by an example. The example is an autoplacer program for designing hybrid circuits
A double label: learning disabilities and emotional problems among gifted children
Many gifted children are "double labeled", namely in addition of being gifted they are also learning disabled and/or suffer from emotional, social or behavioral problems. This article will present the difficulties gifted children with a double label have to deal with, especially the difficulties in the educational system. Because of the double label the educational team faces a double challenge, in most cases without being equipped with the required knowledge or the support they need. This article will describe three case studies; techniques for intervention with such children and their families will be suggested
Az érfal trombogenitása és annak szabályozása = Vessel wall thrombogenicity and its regulation
FiziolĂłgiás hemosztázis ill. artĂ©riás trombĂłzis keletkezĂ©sekor a trombociták a gyorsan áramlĂł vĂ©rbĹ‘l von Willebrand faktoron keresztĂĽl tapadnak ki az Ă©rfalban lĂ©vĹ‘ kollagĂ©nhez. Az Ă©rfal mátrix komponenseit vizsgálva megállapĂtottuk, hogy a media rĂ©tegbĹ‘l izolálhatĂł proteoglikánok, a perlecan Ă©s a biglycan/decorin gátolják a von Willebrand faktor kötĹ‘dĂ©sĂ©t a kollagĂ©nhez, Ă©s Ăgy a jelenlĂ©tĂĽkben in vitro kialakulĂł kollagĂ©n struktĂşra antitrombogĂ©n. Az adventitia proteoglikánok a kollagĂ©n trombogenitását nem befolyásolják. A media proteoglikánok antitrombotikus tulajdonsága perlecan esetĂ©ben a fehĂ©rje komponenshez, mĂg biglycan, decorin esetĂ©ben az adventitia rĂ©tegĂ©tĹ‘l eltĂ©rĹ‘ kondroitin szulfát/dermatán szulfát oldalláncokhoz köthetĹ‘. Kimutattuk, hogy plazmin, trombin, Ă©s neutrofil granulocita metalloproteinázok fokozzák az Ă©rfal media rĂ©tegĂ©ben lĂ©vĹ‘ kollagĂ©n trombogenitását, ami gyulladásban ill. hemosztázisban fokozott trombĂłzishajlamhoz vezethet. Az artĂ©riás trombusban a trombociták egymáshoz fibrinogĂ©nen, von Willebrand faktoron keresztĂĽl kapcsolĂłdnak. MegállapĂtottuk, hogy fiziolĂłgiás koncentráciĂł viszonyok esetĂ©n a von Willebrand faktor vĂ©di a fibrinogĂ©nt a plazmin hasĂtása ellen, Ă©s bár Ĺ‘ is plazmin szubsztrát, a hatás nem a szubsztrátok kompetĂciĂłján alapul. ArtĂ©riás trombusban a fibrinogĂ©n kb. 50 %-a fibrinnĂ© alakul, ennek degradáciĂłját a von Willebrand faktor nem befolyásolja. | In the course of hemostasis or arterial thrombosis platelets are captured from rapidly flowing blood by von Willebrand factor immobilized on vascular collagens. Collagen structures in the media layer of vessel wall, however, do not support platelet adhesion. We have found that perlecan and biglycan/decorin isolated from the media layer of the arterial wall, but none of the adventitia proteoglycans, inhibit von Willebrand factor binding to collagen and platelet adhesion to reconstituted collagen surfaces. The antithrombotic effect of perlecan is due to its core protein component, whereas the inhibitory effects of media biglycan and decorin are attributable to their chondroitin sulphate/dermatan sulphate chains, which are different from those in adventitia biglycan and decorin. We have shown that the antithrombotic properties of the media collagen structures, in situ, can be disrupted by plasmin, thrombin and matrix metalloproteases of neutrophil granulocytes, which suggests that vascular thrombogenicity may increase at sites of inflammation and when the hemostatic system is activated. In platelet-rich thrombi fibrinogen and von Willebrand factor serve as molecular bridges between platelets. Our data indicate that von Willebrand factor protects fibrinogen, but not fibrin from plasmin degradation. Although von Willebrand factor is also a substrate for plasmin, its protective effect is not due to substrate competition
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