scholarly journals Diffusion properties of self-propelled particles in cellular flows

Soft Matter ◽  
2020 ◽  
Vol 16 (23) ◽  
pp. 5431-5438
Author(s):  
Lorenzo Caprini ◽  
Fabio Cecconi ◽  
Andrea Puglisi ◽  
Alessandro Sarracino
Keyword(s):  
Laminar Flow ◽  
Convective Flow ◽  
Active Force ◽  
Cellular Flows ◽  
Steady Laminar ◽  
Diffusion Properties

We study the dynamics of a self-propelled particle advected by a steady laminar flow unveiling its diffusive properties due to the interplay between the active force and the convective flow.

scholarly journals Anomalous mobility of a driven active particle in a steady laminar flow

2018 ◽  
Vol 30 (26) ◽  
pp. 264002 ◽  
Author(s):  
F Cecconi ◽  
A Puglisi ◽  
A Sarracino ◽  
A Vulpiani
Keyword(s):  
Laminar Flow ◽  
Active Particle ◽  
Steady Laminar

Steady Laminar Flow through Twisted Pipes: Fluid Flow in Square Tubes

1981 ◽  
Vol 103 (4) ◽  
pp. 785-790 ◽  
Author(s):  
J. H. Masliyah ◽  
K. Nandakumar
Keyword(s):  
Laminar Flow ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Dissipation Term ◽  
Axial Velocity Profile ◽  
Secondary Motion ◽  
Qualitative Nature ◽  
Flow Through ◽  
Steady Laminar

The Navier-Stokes equation in a rotating frame of reference is solved numerically to obtain the flow field for a steady, fully developed laminar flow of a Newtonian fluid in a twisted tube having a square cross-section. The macroscopic force and energy balance equations and the viscous dissipation term are presented in terms of variables in a rotating reference frame. The computed values of friction factor are presented for dimensionless twist ratios, (i.e., length of tube over a rotation of π radians normalized with respect to half the width of tube) of 20, 10, 5 and 2.5 and for Reynolds numbers up to 2000. The qualitative nature of the axial velocity profile was observed to be unaffected by the swirling motion. The secondary motion was found to be most important near the wall.

Laminar Flow on Endothelial Cells Suppresses eNOS O-GlcNAcylation to Promote eNOS Activity

2021 ◽  
Author(s):  
Sarah Basehore ◽  
Samantha Bohlman ◽  
Callie Weber ◽  
Swathi Swaminathan ◽  
Yuji Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Laminar Flow ◽  
No Production ◽  
Disturbed Flow ◽  
Enos Activity ◽  
Enos Phosphorylation ◽  
Steady Laminar ◽  
In Cells

Rationale: In diabetic animals as well as high glucose cell culture conditions, endothelial nitric oxide synthase (eNOS) is heavily O-GlcNAcylated, which inhibits its phosphorylation and nitric oxide (NO) production. It is unknown, however, whether varied blood flow conditions, which affect eNOS phosphorylation, modulate eNOS activity via O-GlcNAcylation-dependent mechanisms. Objective: The goal of this study was to test if steady laminar flow, but not oscillating disturbed flow, decreases eNOS O-GlcNAcylation, thereby elevating eNOS phosphorylation and NO production. Methods and Results: Human umbilical vein endothelial cells (HUVEC) were exposed to either laminar flow (20 dynes/cm2 shear stress) or oscillating disturbed flow (4{plus minus}6 dynes/cm2 shear stress) for 24 hours in a cone-and-plate device. eNOS O-GlcNAcylation was almost completely abolished in cells exposed to steady laminar but not oscillating disturbed flow. Interestingly, there was no change in protein level or activity of key O-GlcNAcylation enzymes (OGT, OGA, or GFAT). Instead, metabolomics data suggest that steady laminar flow decreases glycolysis and hexosamine biosynthetic pathway (HBP) activity, thereby reducing UDP-GlcNAc pool size and consequent O-GlcNAcylation. Inhibition of glycolysis via 2-deoxy-2-glucose (2-DG) in cells exposed to disturbed flow efficiently decreased eNOS O-GlcNAcylation, thereby increasing eNOS phosphorylation and NO production. Finally, we detected significantly higher O-GlcNAcylated proteins in endothelium of the inner aortic arch in mice, suggesting that disturbed flow increases protein O-GlcNAcylation in vivo. Conclusions: Our data demonstrate that steady laminar but not oscillating disturbed flow decreases eNOS O-GlcNAcylation by limiting glycolysis and UDP-GlcNAc substrate availability, thus enhancing eNOS phosphorylation and NO production. This research shows for the first time that O-GlcNAcylation is regulated by mechanical stimuli, relates flow-induced glycolytic reductions to macrovascular disease, and highlights targeting HBP metabolic enzymes in endothelial cells as a novel therapeutic strategy to restore eNOS activity and prevent EC dysfunction in cardiovascular disease.

Converting steady laminar flow to oscillatory flow through a hydroelasticity approach at microscales

Lab on a Chip ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 60-64 ◽  
Author(s):  
H. M. Xia ◽  
Z. P. Wang ◽  
W. Fan ◽  
A. Wijaya ◽  
W. Wang ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Oscillatory Flow ◽  
Flow Through ◽  
Steady Laminar

On quasi-steady laminar flow separation in the upper airways

2009 ◽  
Vol 25 (5) ◽  
pp. 447-461 ◽  
Author(s):  
A. Van Hirtum ◽  
J. Cisonni ◽  
X. Pelorson
Keyword(s):  
Laminar Flow ◽  
Flow Separation ◽  
Upper Airways ◽  
Steady Laminar

Applying Quasi-Linearization to the Problem of Steady Laminar Flow of a Second Grade Fluid Between Two Rotating Porous Disks

1984 ◽  
Vol 106 (4) ◽  
pp. 448-455 ◽  
Author(s):  
P. D. Verma ◽  
P. R. Sharma ◽  
P. D. Ariel
Keyword(s):  
Laminar Flow ◽  
Equations Of Motion ◽  
Elastic Parameter ◽  
Rotation Parameter ◽  
Second Grade ◽  
Second Grade Fluid ◽  
Regular Perturbation ◽  
Injection Parameter ◽  
Grade Fluid ◽  
Steady Laminar

The problem of steady laminar flow of an incompressible second grade fluid between two rotating porous disks has been investigated. The equations of motion are solved by regular perturbation method for small suction/injection parameter and by the quasilinearization method for higher values of suction/injection parameter. The results from both the methods have been compared for both the Newtonian and Non-Newtonian fluids. The effects of suction/injection parameter, rotation parameter and visco-elastic parameter on the velocity components and skin friction have been discussed numerically and shown graphically.

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