Spatio-temporal variations in cell-free layer formation near bifurcations of small arterioles

2012 ◽  
Vol 83 (2) ◽  
pp. 118-125 ◽  
Author(s):  
Peng Kai Ong ◽  
Swati Jain ◽  
Sangho Kim
Keyword(s):  
Temporal Variations ◽  
Layer Formation ◽  
Free Layer ◽  
Spatio Temporal ◽  
Cell Free Layer

scholarly journals Spatial and temporal variations of cell‐free layer in arterioles

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Robert Li‐Chung Kong ◽  
Sangho Kim ◽  
Aleksander S. Popel ◽  
Marcos Intaglietta ◽  
Paul C. Johnson
Keyword(s):  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Free Layer ◽  
Cell Free Layer

Cell-Free Layer Formation in Small Arterioles at Pathological Levels of Erythrocyte Aggregation

2011 ◽  
Vol 18 (7) ◽  
pp. 541-551 ◽  
Author(s):  
PENG KAI ONG ◽  
SWATI JAIN ◽  
BUMSEOK NAMGUNG ◽  
YEON I. WOO ◽  
SANGHO KIM
Keyword(s):  
Erythrocyte Aggregation ◽  
Layer Formation ◽  
Free Layer ◽  
Cell Free Layer

Effects of cell-free layer formation on NO/O2 bioavailability in small arterioles

2012 ◽  
Vol 83 (2) ◽  
pp. 168-177 ◽  
Author(s):  
Peng Kai Ong ◽  
Seungkwan Cho ◽  
Bumseok Namgung ◽  
Sangho Kim
Keyword(s):  
Layer Formation ◽  
Free Layer ◽  
Cell Free Layer

Temporal and spatial variations of cell-free layer width in arterioles

2007 ◽  
Vol 293 (3) ◽  
pp. H1526-H1535 ◽  
Author(s):  
Sangho Kim ◽  
Robert L. Kong ◽  
Aleksander S. Popel ◽  
Marcos Intaglietta ◽  
Paul C. Johnson
Keyword(s):  
Correlation Length ◽  
Vessel Diameter ◽  
Temporal Variations ◽  
Hydraulic Pressure ◽  
Free Layer ◽  
Layer Width ◽  
Mean Width ◽  
The Mean ◽  
Non Gaussian ◽  
Cell Free Layer

Separation of red blood cells and plasma in microcirculatory vessels produces a cell-free layer at the wall. This layer may be an important determinant of blood viscosity and wall shear stress in arterioles, where most of the hydraulic pressure loss in the circulatory system occurs and flow regulatory mechanisms are prominent. With the use of a newly developed method, the width of the cell-free layer was rapidly and repeatedly determined in arterioles (10- to 50-μm inner diameter) in the rat cremaster muscle at normal arterial pressure. The temporal variation of the cell-free layer width was non-Gaussian, but calculated mean and median values differed by <0.2 μm. The correlation length of the temporal variations downstream (an indication of mixing) was ∼30 μm and was independent of pseudoshear rate (ratio of mean velocity to vessel diameter) and of vessel diameter. The cell-free layer width was significantly different on opposite sides of the vessel and inversely related. Increasing red blood cell aggregability reduced this inverse relation but had no effect on correlation length. In the diameter range studied, the mean width of the cell-free layer increased from 0.8 to 3.1 μm and temporal variations increased from 30% to 70% of the mean width. Increased aggregability did not alter either relationship. In summary, the cell-free layer width in arterioles is diameter dependent and shows substantial non-Gaussian temporal variations. The temporal variations increase as diameter increases and are inversely related on opposite sides of the vessel.

scholarly journals Effect of erythrocyte aggregation and flow rate on cell-free layer formation in arterioles

2010 ◽  
Vol 298 (6) ◽  
pp. H1870-H1878 ◽  
Author(s):  
Peng Kai Ong ◽  
Bumseok Namgung ◽  
Paul C. Johnson ◽  
Sangho Kim
Keyword(s):  
Blood Cell ◽  
Flow Rate ◽  
Red Blood Cell ◽  
Cell Aggregation ◽  
Rheological Parameters ◽  
Layer Formation ◽  
Free Layer ◽  
Layer Width ◽  
Red Blood Cell Aggregation ◽  
Cell Free Layer

Formation of a cell-free layer is an important dynamic feature of microcirculatory blood flow, which can be influenced by rheological parameters, such as red blood cell aggregation and flow rate. In this study, we investigate the effect of these two rheological parameters on cell-free layer characteristics in the arterioles (20–60 μm inner diameter). For the first time, we provide here the detailed temporal information of the arteriolar cell-free layer in various rheological conditions to better describe the characteristics of the layer variation. The rat cremaster muscle was used to visualize arteriolar flows, and the extent of aggregation was raised by dextran 500 infusion to levels seen in normal human blood. Our results show that cell-free layer formation in the arterioles is enhanced by a combination of flow reduction and red blood cell aggregation. A positive relation ( P < 0.005) was found between mean cell-free layer widths and their corresponding SDs for all conditions. An analysis of the frequency and magnitudes of cell-free layer variation from their mean value revealed that the layer deviated with significantly larger magnitudes into the red blood cell core after flow reduction and dextran infusion ( P < 0.05). In accordance, the disparity of cell-free layer width distribution found in opposite radial directions from its mean became greater with aggregation in reduced flow conditions. This study shows that the cell-free layer width in arterioles is dependent on both flow rate and red blood cell aggregability, and that the temporal variations in width are asymmetric with a greater excursion into the red blood cell core than toward the vessel wall.

Spatio-temporal variations of winter wheat water requirement and climatic causes in Huang-Huai-Hai Farming Region

2012 ◽  
Vol 20 (3) ◽  
pp. 356-362 ◽  
Author(s):  
Xiao-Lin YANG ◽  
Zhen-Wei SONG ◽  
Hong WANG ◽  
Quan-Hong SHI ◽  
Fu CHEN ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Temporal Variations ◽  
Water Requirement ◽  
Spatio Temporal
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