https://www.selleckchem.com/products/CP-690550.html Both full-length and cleaved forms of YRS were taken up by platelets in vitro and stored in the α-granules. The N-terminal YRS fragment generated by proteolytic cleavage had monocyte activation comparable to that of the constitutive-active mutant YRS (YRS ) previously reported. Platelets take up both full-length YRS and the active form of cleaved YRS fragment from the plasma. The cleaved, N-terminal YRS fragment stored in α-granules may have potential to activate monocytes. Platelets take up both full-length YRS and the active form of cleaved YRS fragment from the plasma. The cleaved, N-terminal YRS fragment stored in α-granules may have potential to activate monocytes. Hemostatic clots have a P-selectin positive platelet core covered with a shell of P-selectin negative platelets. To develop a new human blood microfluidic assay to interrogate core/shell mechanics. A 2-stage assay perfused whole blood over collagen/± tissue factor (TF) for 180seconds at 100s wall shear rate, followed by buffer perfusion at either 100s (venous) or 1000s (arterial). This microfluidic assay used an extended channel height (120µm), allowing buffer perfusion well before occlusion. Clot growth on collagen stopped immediately with buffer exchange, revealing ~10% reduction in platelet fluorescence intensity (at 100s ) and ~30% (at 1000s ) by 1200seconds. Thrombin generation (on collagen/TF) reduced erosion at either buffer flow rate. P-selectin-positive platelets were stable (no erosion) against 1000s , in contrast to P-selectin negative platelets. Thrombin inhibition (with D-Phe-Pro-Arg-CMK) reduced the number of P-selectin-positive platelets and lowered thrombus stability through the reduction of P-selectin-positive platelets. Interestingly, fibrin inhibition (with H-Gly-Pro-Arg-Pro-OH acetate salt) increased the number of P-selectin-positive platelets but did not lower stability, suggesting that fibrin was only in the core region. Thromb