Upstream velocity profile (solid circle •) and velocity profile above a cell (open circle ○) were overlapped.

<p>Upstream velocity profile (solid circle •) and velocity profile above a cell (open circle ○) were overlapped.</p

Comparison between current CFD and μPIV results with previous ones.

<p>Comparison between current CFD and μPIV results with previous ones.</p

Velocity profile in side-view flow chamber measured by μPIV.

<p>The dimension for a side-view flow chamber is 550 µm high and 700 µm wide. Images were captured only in the middle 1/3 region across the width. A) X-velocity calculated from images taken by a 10× objective lens was plotted with respect to distance from the center of chamber showing a parabolic curve pattern. B) X-velocity calculated from images taken by a 40× objective lens was plotted with respect to distance from substrate and showed a linear curve pattern.</p

Shear rates above a TC and a PMN under a condition of low shear (73 µl min⁻¹).

<p>A) Quadratic curve fitting for velocity profiles above an adherent PMN in 2-cell height region; B) Quadratic curve fitting for velocity profiles above an adherent TC in 2-cell height region.</p

Drag forces calculated on deformed TCs under low shear (73 µl/min; solid square ▪) and high shear high shear (365 µl min⁻¹; open circle ○).

<p>Drag forces calculated on deformed TCs under low shear (73 µl/min; solid square ▪) and high shear high shear (365 µl min⁻¹; open circle ○).</p

Velocity profile above an adherent PMN (open circle ○), above a TC (open triangle Δ) and the upstream (solid diamond ⧫).

<p>Velocity profile above an adherent PMN (open circle ○), above a TC (open triangle Δ) and the upstream (solid diamond ⧫).</p

Reynolds number calculated from μPIV results.

<p>Reynolds number calculated from μPIV results.</p

Schematic diagram of a coupled side-view μPIV system (not to scale).

<p>A) The flow chamber was constructed by two microslides with a smaller one being inserted into a bigger one, and two 45° mirrors coated with a high-reflected layer placed on each side of the chamber. The light path for a top-view (lower) and a side-view (upper) is illustrated <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030721#pone.0030721-Cao1" target="_blank">[58]</a>. B) μPIV components include a double-pulse Nd: YAG laser, a camera, a synchronizer, an amplifier and other optical components, as well as a microscope with fluorescent cubes and an objective lens. It also shows an optical path for a side-view μPIV imaging.</p

Cell Reynolds number calculations.

<p>A) an adherent PMN for five relative PMN-to-TC position states; and B) an adherent TC for four relative PMN-to-TC position states (the transient aggregate state was excluded). Open triangles (△) represent a low shear condition (73 µl min⁻¹), and open circles (○) represent a high shear condition (365 µl min⁻¹).</p

Comparison of velocity profiles above a single adherent PMN under low shear (73 µl/min; solid diamond ⧫) and high shear (365 µl min⁻¹; open square □).

<p>Comparison of velocity profiles above a single adherent PMN under low shear (73 µl/min; solid diamond ⧫) and high shear (365 µl min⁻¹; open square □).</p