Toad red blood cells were used to measure regional bone blood flow in the canine mandibular ramus. The blood cells were labelled with sodium pertechnetate and fixed in 1 0%formalin; they were 22 × 15 μm in size ...Toad red blood cells were used to measure regional bone blood flow in the canine mandibular ramus. The blood cells were labelled with sodium pertechnetate and fixed in 1 0%formalin; they were 22 × 15 μm in size and had a specific gravity close to that of dog red blood cells. These cells had no discernible effect on systemic hemodynamics after injection, did not agglutinate, were well mixed and evenly distributed throughout the body, and were completely extracted in one circulation through the mandible. The mandibular ramus was divided into six regions. and the blood flow rates in each were found to be similar to those reported in previous studies with radiolabelled carbonized, microspheres. Furthermore, the blood flow distribution pattern of the mandibular ramus determined in this study was identical to that of our previous study using the bone-seeking radionuclide method. We suggest that radiolabelled toad red blood cells are an ideal marker for measuring regional blood flow in the canine mandible.展开更多
A lattice Boltzmann model is presented to simulate the deformation and motions of a red blood cell （RBC） in a shear flow. The curvatures of the membrane of a static RBC with different chemical potentiM drops calcula...A lattice Boltzmann model is presented to simulate the deformation and motions of a red blood cell （RBC） in a shear flow. The curvatures of the membrane of a static RBC with different chemical potentiM drops calculated by our model agree with those computed by a shooting method very well. Our simulation results show that in a shear flow, biconcave RBC becomes highly flattened and undergoes tank-treading motion. With intrinsically parallel dynamics, this lattice Boltzmann method is expected to find wide applications to both single and multi-vesicles suspension as well as complex open membranes in various fluid flows for a wide range of Reynolds numbers.展开更多
The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompre...The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method(IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell(including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.展开更多
文摘Toad red blood cells were used to measure regional bone blood flow in the canine mandibular ramus. The blood cells were labelled with sodium pertechnetate and fixed in 1 0%formalin; they were 22 × 15 μm in size and had a specific gravity close to that of dog red blood cells. These cells had no discernible effect on systemic hemodynamics after injection, did not agglutinate, were well mixed and evenly distributed throughout the body, and were completely extracted in one circulation through the mandible. The mandibular ramus was divided into six regions. and the blood flow rates in each were found to be similar to those reported in previous studies with radiolabelled carbonized, microspheres. Furthermore, the blood flow distribution pattern of the mandibular ramus determined in this study was identical to that of our previous study using the bone-seeking radionuclide method. We suggest that radiolabelled toad red blood cells are an ideal marker for measuring regional blood flow in the canine mandible.
基金supported by National Natural Science Foundation of China under Grant No. 10747004the Guangxi Science Foundation under Grant Nos. 0640064 and 0542045
文摘A lattice Boltzmann model is presented to simulate the deformation and motions of a red blood cell （RBC） in a shear flow. The curvatures of the membrane of a static RBC with different chemical potentiM drops calculated by our model agree with those computed by a shooting method very well. Our simulation results show that in a shear flow, biconcave RBC becomes highly flattened and undergoes tank-treading motion. With intrinsically parallel dynamics, this lattice Boltzmann method is expected to find wide applications to both single and multi-vesicles suspension as well as complex open membranes in various fluid flows for a wide range of Reynolds numbers.
基金supported by the National Key Project of Scientific and Technical Supporting Programs of China(Grant No.2014BAI11B06)the National Natural Science Foundation of China(Grant No.11172156)
文摘The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method(IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell(including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.
