Analysis of Thrombus Formation Process by Flow Induced High Shear Rate Using Optical Observation Method

2013 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Formation Process ◽  
Thrombus Formation ◽  
Laser Sheet ◽  
Formation Rate ◽  
High Shear Rate ◽  
Square Root ◽  
High Shear ◽  
Observation Method

This paper describes visualization of thrombus formation process on orifice flows by laser sheet beam and normal illumination. The aim is to investigate the effects of shear stress or shear rate on the thrombus formation or thrombus formation rate. It was found that the white thrombus formation rate is proportional to square root of shear rate, and the white thrombus is dominant when the shear rate is more than 450 (1/s).

Effects of High Shear Rate on Thrombus Formation Rate on Pipe Orifice Flows Using Laser Sheet Method and the Prediction of Thrombus Formation Rate by CFD

2012 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Plasma Flow ◽  
Formation Process ◽  
Thrombus Formation ◽  
Laser Sheet ◽  
Formation Rate ◽  
High Shear Rate ◽  
High Shear ◽  
Rate Region

This paper describes visualization of thrombus formation process on orifice flows by laser sheet beam. The aim is to investigate the effects of shear stress or shear rate on the thrombus formation or thrombus formation rate. In this investigation, by visualization of the thrombus formation in blood plasma flow, it was found that the high shear rate region of the flow has large effects of the thrombus formation.

Effects of High Shear Rate on Thrombus Formation Process on Pipe Orifice Flows

2011 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Shear Rate ◽  
Formation Process ◽  
Thrombus Formation ◽  
Laser Sheet ◽  
Formation Rate ◽  
Prediction Method ◽  
High Shear Rate ◽  
High Shear ◽  
High Shear Stress ◽  
Rate Region

This paper describes visualization of thrombus formation process on orifice flows by laser sheet beam. The aim is to investigate the effects of high shear stress or shear rate on the thrombus formation or thrombus formation rate. In addition, the experimental results are compared with the CFD results. As a result, it was found that the high shear rate region of the flow has large effects of the thrombus formation and prediction method based on CFD can be used.

Visualization of Thrombus Formation Process on Pipe Orifice Flows by Laser Sheet

2010 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Blood Plasma ◽  
Plasma Flow ◽  
Formation Process ◽  
Thrombus Formation ◽  
Laser Sheet ◽  
Formation Rate ◽  
High Shear ◽  
Rate Region

This paper describes visualization of thrombus formation process on orifice flows by laser sheet beam. The aim is to investigate the effects of shear stress or shear rate on the thrombus formation or thrombus formation rate. In this investigation, by visualization of the thrombus formation in blood plasma flow, it was found that the high shear rate region of the flow has large effects of the thrombus formation.

Observation of Thrombus Formation Process by High Shear Rate on Various Flows and CFD Based Prediction Method for Thrombus Formation Rate

2014 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Quantitative Evaluation ◽  
Formation Process ◽  
Thrombus Formation ◽  
Formation Rate ◽  
Prediction Method ◽  
High Shear Rate ◽  
High Shear

This paper describes visualization of thrombus formation process on orifice flows and Couette flows by normal illumination. The aim is to investigate the effects of shear stress or shear rate on the thrombus formation or thrombus formation rate. It was found that (1) effect of flow types on the thrombus ratio was obtained and (2) quantitative evaluation of thrombus formation rate by our proposed CFD based prediction method was established for various flows.

Von Willebrand factor C1C2 domain is involved in platelet adhesion to polymerized fibrin at high shear rate

Blood ◽  
2004 ◽  
Vol 103 (5) ◽  
pp. 1741-1746 ◽  
Author(s):  
Jeffrey F. W. Keuren ◽  
Dominique Baruch ◽  
Paulette Legendre ◽  
Cécile V. Denis ◽  
Peter J. Lenting ◽  
...  
Keyword(s):  
Shear Rate ◽  
Binding Site ◽  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
High Shear Rate ◽  
High Shear ◽  
Perfusion Studies ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractFibrin is actively involved in platelet reactions essential for thrombus growth, in which von Willebrand factor (VWF) might be an important mediator. The aim of this study was to localize VWF domains that bind to fibrin and to determine their relevance in platelet adhesion. VWF binds specifically to fibrin with an apparent Kd of 2.2 μg/mL. Competition in the presence of 2 complementary fragments, SpIII (residues 1-1365) and SpII (residues 1366-2050), indicated that the high affinity binding site for fibrin is located in the C-terminal part, thus distinct from the A domains. Comparison of 2 deleted rVWF (ΔD4B-rVWF, ΔC1C2-rVWF) suggested that the C1C2 domains contained a fibrin binding site. This site is distinct from RGD, as shown by binding of D1746G-rVWF to fibrin. Perfusion studies at high shear rate demonstrated that C1C2 domains were required for optimal platelet adhesion to fibrin. With the use of a VWF-deficient mouse model, it was found that plasma VWF is critical for platelet tethering and adhesion to fibrin. These results suggest a dual role of fibrin-bound VWF in thrombus formation: first, fibrin-bound VWF is critical in the recruitment of platelets by way of glycoprotein (GP) Ib, and, second, it contributes to stationary platelet adhesion by way of binding to activated αIIbβ3.

Morphology and rheology of PP/POE blends in high shear stress field

2017 ◽  
Vol 31 (9) ◽  
pp. 1263-1280 ◽  
Author(s):  
Jiru Ying ◽  
Xiaolin Xie ◽  
Shaoxian Peng ◽  
Huamin Zhou ◽  
Dequn Li
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Stress Field ◽  
Polymer Blends ◽  
Morphological Evolution ◽  
High Shear Rate ◽  
Dispersed Phase ◽  
High Shear ◽  
High Shear Stress ◽  
Shear Stress Field

Polypropylene (PP)/polyolefin elastomer (POE; ethylene–octene copolymer) blends with varying weight percentages of POE were prepared in a twin-screw extruder and molded through high shear rate injection-molding process. The morphologies and rheology of the PP/POE blends were systematically investigated based on rheological data and experimental analysis. The results indicate that the polymer blends of plastic and rubber in a high shear stress field result in a multilayered microstructure, which can be divided into skin, transitional, shear, and core layers according to the morphology of the dispersed phase. The morphology formation of the dispersed phase depends on the shear field and temperature field in the processing. Morphological evolution of the dispersed POE phases in PP matrix was described and quantified. A dragging ellipsoid model and capillary number were employed to describe the morphological evolution of the dispersed phase, and the morphological parameters were obtained. The results show that the dragging ellipsoid model is well suited to explain the morphological evolution of the dispersed phase in polymer blends molded under high shear rate.

scholarly journals Shear Stress Measurements of Non-Spherical Particles in High Shear Rate Flows

2008 ◽  
Author(s):  
Erin Koos ◽  
Melany L. Hunt ◽  
Christopher E. Brennen ◽  
Albert Co ◽  
Gary L. Leal ◽  
...  
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
High Shear Rate ◽  
Spherical Particles ◽  
High Shear ◽  
Stress Measurements
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