Lim Hyun-Jung, Nam Jeong-Hun, Lee Yong-Jin, Shin Sehyun
School of Mechanical Engineering, Korea University, Seoul 136-713, Republic of Korea.
Rev Sci Instrum. 2009 Sep;80(9):096101. doi: 10.1063/1.3223534.
Red blood cell (RBC) aggregation is becoming an important hemorheological parameter, which typically exhibits temperature dependence. Quite recently, a critical shear-stress was proposed as a new dimensional index to represent the aggregative and disaggregative behaviors of RBCs. The present study investigated the effect of the temperature on the critical shear-stress that is required to keep RBC aggregates dispersed. The critical shear-stress was measured at various temperatures (4, 10, 20, 30, and 37 degrees C) through the use of a transient microfluidic aggregometry. The critical shear-stress significantly increased as the blood temperature lowered, which accorded with the increase in the low-shear blood viscosity with the lowering of the temperature. Furthermore, the critical shear-stress also showed good agreement with the threshold shear-stress, as measured in a rotational Couette flow. These findings assist in rheologically validating the critical shear-stress, as defined in the microfluidic aggregometry.
红细胞（RBC）聚集正成为一个重要的血液流变学参数，其通常表现出温度依赖性。最近，临界剪切应力被提议作为一种新的维度指标来表征红细胞的聚集和解聚行为。本研究调查了温度对保持红细胞聚集体分散所需的临界剪切应力的影响。通过使用瞬态微流控聚集测定法，在不同温度（4、10、20、30和37摄氏度）下测量临界剪切应力。随着血液温度降低，临界剪切应力显著增加，这与随着温度降低低剪切血液粘度的增加相一致。此外，临界剪切应力也与在旋转库埃特流中测量的阈值剪切应力显示出良好的一致性。这些发现有助于从流变学角度验证微流控聚集测定法中定义的临界剪切应力。
