The Place of Dielectric Spectroscopy in Probing Electrorheology

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1829-1836 ◽  
Author(s):  
S. Kyvelidis ◽  
G. M. Maistros ◽  
P. Rattray ◽  
H. Block ◽  
J. Akhavan ◽  
...  
Keyword(s):  
Electric Fields ◽  
Working Conditions ◽  
High Shear ◽  
Empirical Correlations ◽  
Electrical Parameters ◽  
Shear Rates ◽  
Uniform Shear ◽  
High Shear Rates ◽  
Er Fluids ◽  
Er Fluid

The measurement of the dielectric spectra of PAnQR based ER fluids under shear and electric fields is discussed and results presented. Data in which either but not both shear or electric fields are present are submitted to analysis in terms of known theories. For flow alone, that analysis provides information on the attenuation of polarization by the uniform shear fields whilst the polarization of quiescent fluids by electric fields may lead to estimates of particles packing within the columns. Permittivity data when both fields are acting is presented, but in the absence of suitable theory, not modelled quantitatively. Empirical correlations are discussed and the conclusion drawn that fibrillation is readily suppressed by even moderate shear rates, although long range dipolar forces still persist to high shear rates. The dc conductance of these fluids have also been measured. This together with permittivity data under ER fluid working conditions has importance in establishing the electrical parameters for any ER fluid.

Relative Involvement of GPIb/IX-vWF Axis and GPIIb/IIIa in Thrombus Growth at High Shear Rates in the Guinea Pig

1997 ◽  
Vol 17 (5) ◽  
pp. 919-924 ◽  
Author(s):  
Patrick André ◽  
Patricia Hainaud ◽  
Claire Bal dit Sollier ◽  
Leonard I. Garfinkel ◽  
Jacques P. Caen ◽  
...  
Keyword(s):  
Guinea Pig ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates

scholarly journals Microfluidic rheology: A new approach to measure viscosity of ceramic suspensions at extremely high shear rates

Open Ceramics ◽  
2021 ◽  
Vol 5 ◽  
pp. 100052
Author(s):  
V. Carnicer ◽  
C. Alcázar ◽  
M.J. Orts ◽  
E. Sánchez ◽  
R. Moreno
Keyword(s):  
High Shear ◽  
New Approach ◽  
Shear Rates ◽  
High Shear Rates ◽  
Ceramic Suspensions

Flow curves of mixtures of acrylonitrile–styrene copolymers with different molecular weights at extremely high shear rates (abstract)

1991 ◽  
Vol 35 (4) ◽  
pp. 706-706
Author(s):  
Hideroh Takahashi ◽  
Yoshinori Inoue ◽  
Satoru Yamamoto ◽  
Osami Kamigaito
Keyword(s):  
High Shear ◽  
Flow Curves ◽  
Shear Rates ◽  
Molecular Weights ◽  
Styrene Copolymers ◽  
High Shear Rates

Comparison of antithrombotic efficacy between edoxaban, a direct factor Xa inhibitor, and fondaparinux, an indirect factor Xa inhibitor under low and high shear rates

2011 ◽  
Vol 106 (12) ◽  
pp. 1062-1068 ◽  
Author(s):  
Naoki Tsuji ◽  
Yuko Honda ◽  
Chikako Kamisato ◽  
Yoshiyuki Morishima ◽  
Toshiro Shibano ◽  
...  
Keyword(s):  
Shear Rate ◽  
Arterial Thrombosis ◽  
Factor Xa ◽  
High Shear ◽  
Shear Rates ◽  
Thrombosis Model ◽  
Perfusion Chamber ◽  
High Shear Rates ◽  
Antithrombotic Effects ◽  
Antithrombotic Efficacy

SummaryEdoxaban is an oral, direct factor Xa (FXa) inhibitor under late-phase clinical development. This study compared the antithrombotic efficacy of edoxaban with that of an indirect FXa inhibitor, fondaparinux, in in vivo venous and arterial thrombosis models and in ex vivo perfusion chamber thrombosis model under low and high shear rates in rats. Venous and arterial thrombi were induced by platinum wire insertion into the inferior vena cava and by application of FeCl3 to the carotid artery, respectively. The perfusion chamber thrombus was formed by blood perfusion into a collagen-coated capillary at 150 s-1 (low shear rate) and 1,600 s-1 (high shear rate). Effective doses of edoxaban that reduced thrombus formation by 50% (ED50) in venous and arterial thrombosis models were 0.076 and 0.093 mg/kg/h, respectively. In contrast, ED50 of fondaparinux in the arterial thrombosis model (>10 mg/kg/h) was markedly higher compared to ED50 in the venous thrombosis model (0.021 mg/kg/h). In the perfusion chamber thrombosis model, the ratio of ED50 under high shear rate (1.13 mg/kg/h) to that under low shear rate (0.63 mg/kg/h) for edoxaban was 1.9, whereas that for fondaparinux was more than 66. While the efficacy of fondaparinux markedly decreased in arterial thrombosis and in a high-shear state, edoxaban exerted consistent antithrombotic effects regardless of flow conditions. These results suggest that shear rate is a key factor in different antithrombotic effects between edoxaban and fondaparinux.

“Viscosity-plus” Effect in Whole Blood at High Shear Rates

Nature ◽  
1969 ◽  
Vol 221 (5178) ◽  
pp. 365-366 ◽  
Author(s):  
WILLIAM I. ROSENBLUM
Keyword(s):  
Whole Blood ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates

scholarly journals Platelet von Willebrand factor: evidence for its involvement in platelet adhesion to collagen

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 1214-1217
Author(s):  
E Fressinaud ◽  
D Baruch ◽  
C Rothschild ◽  
HR Baumgartner ◽  
D Meyer
Keyword(s):  
Shear Rate ◽  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Von Willebrand Disease ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

Although it is well established that plasma von Willebrand Factor (vWF) is essential to platelet adhesion to subendothelium at high shear rates, the role of platelet vWF is less clear. We studied the respective role of both plasma and platelet vWF in mediating platelet adhesion to fibrillar collagen in a parallel-plate perfusion chamber. Reconstituted blood containing RBCs, various mixtures of labeled washed platelets and plasma from controls or five patients with severe von Willebrand disease (vWD), was perfused through the chamber for five minutes at a shear rate of 1,600 s-1. Platelet-collagen interactions were estimated by counting the radioactivity in deposited platelets and by quantitative morphometry. When the perfusate consisted of normal platelets suspended in normal plasma, platelet deposition on the collagen was 24.7 +/- 3.6 X 10(6)/cm2 (mean +/- SEM, n = 6). Significantly less deposition (16 +/- 2.3) was observed when vWD platelets were substituted for normal platelets. In mixtures containing vWD plasma, significantly greater deposition (9 +/- 2.2) was obtained with normal than with vWD platelets (1 +/- 0.4) demonstrating a role for platelet vWF in mediating the deposition of platelets on collagen. Morphometric analysis confirmed these data. Our findings indicate that platelet, as well as plasma, vWF mediates platelet-collagen interactions at a high shear rate.

Sign in / Sign up

Export Citation Format

Share Document