Some Aspects of Nonlinear Behavior in Lubricants Under Extreme Stress

1968 ◽  
Vol 90 (3) ◽  
pp. 549-552
Author(s):  
F. W. Smith
Keyword(s):  
Shear Stress ◽  
Nonlinear Behavior ◽  
High Shear ◽  
High Shear Stress ◽  
Arrhenius Activation Energy ◽  
Flow Process ◽  
Molecular Fluids ◽  
Extreme Stress ◽  
General Basis ◽  
The Continuum

A general basis for discussing nonlinearity in the flow of molecular fluids consists in applying the continuum mechanics of Coleman and Noll to a flow process governed by an Arrhenius activation energy equation. The theory predicts the familiar exponential increase of viscosity with pressure and a decrease in viscosity with high shear stress, and also predicts the existence of “normal stresses” under high shear stress. Schematic calculations are presented for the behavior of a lubricant under extreme stress.

scholarly journals 5065Platelet desialylation induced by high shear-stress mechanical circulatory support

2018 ◽  
Vol 39 (suppl_1) ◽  
Author(s):  
H Spillemaeker ◽  
A Dupont ◽  
A Kauskot ◽  
A Rauch ◽  
F Vincent ◽  
...  
Keyword(s):  
Shear Stress ◽  
Mechanical Circulatory Support ◽  
Circulatory Support ◽  
High Shear ◽  
High Shear Stress

scholarly journals Nitric Oxide–Dependent and Nitric Oxide–Independent Transcriptional Responses to High Shear Stress in Endothelial Cells

Hypertension ◽  
2005 ◽  
Vol 45 (4) ◽  
pp. 672-680 ◽  
Author(s):  
Branko Braam ◽  
Remmert de Roos ◽  
Hans Bluyssen ◽  
Patrick Kemmeren ◽  
Frank Holstege ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Shear Stress ◽  
High Shear ◽  
High Shear Stress ◽  
Transcriptional Responses

DIFFUSION LIMITED AGGREGATION FROM SHEAR STRESS AS A SIMPLE MODEL OF VASCULOGENESIS

Fractals ◽  
1999 ◽  
Vol 07 (01) ◽  
pp. 33-39 ◽  
Author(s):  
VINCENT FLEURY ◽  
LAURENT SCHWARTZ
Keyword(s):  
Shear Stress ◽  
Dendritic Growth ◽  
High Shear ◽  
Vascular Pattern ◽  
Laplacian Growth ◽  
High Shear Stress ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Capillary Bed ◽  
Arteries And Veins

A model is proposed by which the formation of the vascular network in animals proceeds via progressive penetration of the vessel ramification into a capillary mesh, by means of a laplacian growth mechanism of hydrodynamical origin. In this model, the growth of both arteries and veins follows the directions of high shear stress provoked by the blood flow on the endothelial wall of a pre-existing capillary mesh. This process is shown to be identical to the phenomenon of dendritic growth, which is responsible for the formation of such well-known patterns as dendritic crystals, lightning sparks or branching aggregates of bacteria. A number of straightforward consequences of potentially important medical and physiological interests are deduced. These include the natural and spontaneous organization of the arterial and venal trees, the spontaneous and unavoidable tropism of arteries towards veins and vice-versa, the hierarchical character of the vessels and the possibility of computerized prediction of the vascular pattern from the shape of the capillary bed.

scholarly journals Antithrombotic Effects of Paeoniflorin from Paeonia suffruticosa by Selective Inhibition on Shear Stress-Induced Platelet Aggregation

2019 ◽  
Vol 20 (20) ◽  
pp. 5040 ◽  
Author(s):  
Thien Ngo ◽  
Keunyoung Kim ◽  
Yiying Bian ◽  
Hakjun Noh ◽  
Kyung-Min Lim ◽  
...  
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Ex Vivo ◽  
Antiplatelet Agents ◽  
Human Platelets ◽  
Platelet Glycoprotein ◽  
High Shear ◽  
High Shear Stress ◽  
Paeonia Suffruticosa ◽  
Induced Aggregation

Antiplatelet agents are important in the pharmacotherapeutic regime for many cardiovascular diseases, including thrombotic disorders. However, bleeding, the most serious adverse effect associated with current antiplatelet therapy, has led to many efforts to discover novel anti-platelet drugs without bleeding issues. Of note, shear stress-induced platelet aggregation (SIPA) is a promising target to overcome bleeding since SIPA happens only in pathological conditions. Accordingly, this study was carried out to discover antiplatelet agents selectively targeting SIPA. By screening various herbal extracts, Paeonia suffruticosa and its major bioactive constituent, paeoniflorin, were identified to have significant inhibitory effects against shear-induced aggregation in human platelets. The effects of paeoniflorin on intraplatelet calcium levels, platelet degranulation, and integrin activation in high shear stress conditions were evaluated by a range of in vitro experiments using human platelets. The inhibitory effect of paeoniflorin was determined to be highly selective against SIPA, through modulating von Willebrand Factor (vWF)-platelet glycoprotein Ib (GP Ib) interaction. The effects of paeoniflorin on platelet functions under high shear stress were confirmed in the ex vivo SIPA models in rats, showing the good accordance with the anti-SIPA effects on human platelets. Treatment with paeoniflorin significantly prevented arterial thrombosis in vivo from the dose of 10 mg/kg without prolonging bleeding time or blood clotting time in rats. Collectively, our results demonstrated that paeoniflorin can be a novel anti-platelet agent selectively targeting SIPA with an improved safety profile.

scholarly journals Biomarkers related to hemodynamic abnormalities with high shear stress

2016 ◽  
Vol 67 (2) ◽  
pp. 213 ◽  
Author(s):  
Toru Kubo ◽  
Hiroaki Kitaoka
Keyword(s):  
Shear Stress ◽  
High Shear ◽  
High Shear Stress
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