Changes in velocity profile according to blood viscosity in a microchannel     

Eunseop Yeom  Yang Jun Kang  Sang-Joon Lee 《Biomicrofluidics》2014,8(3)

Red blood cells (RBCs) are important to dictate hemorheological properties of blood. The shear-thinning effect of blood is mainly attributed to the characteristics of the RBCs. Variations in hemorheological properties alter flow resistance and wall shear stress in blood vessels. Therefore, detailed understanding of the relationship between the hemorheological and hemodynamic properties is of great importance. In this study, blood viscosity and blood flow were simultaneously measured in the same microfluidic device by monitoring the flow-switching phenomenon. To investigate blood flows according to hemorheological variations, the flow rate of blood samples (RBCs suspended in autologous plasma, dextran-treated plasma, and in phosphate buffered saline solution) was precisely controlled with a syringe pump. Velocity profiles of blood flows were measured by using a micro-particle image velocimetry technique. The shape of velocity profiles was quantified by using a curve-fitting equation. It is found that the shape of the velocity profiles is highly correlated with blood viscosity. To demonstrate the relationship under ex vivo conditions, biophysical properties and velocity profiles were measured in an extracorporeal rat bypass loop. Experimental results show that increased blood viscosity seems to induce blunt velocity profile with high velocity component at the wall of the microchannel. Simultaneous measurement of blood viscosity and velocity profile would be useful for understanding the effects of hemorheological features on the hemodynamic characteristics in capillary blood vessels.  相似文献   

Editorial     

Dr Celia Whitchurch  Professor Lee Harvey 《Higher Education Quarterly》2010,64(1):2-3

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Leaving Ceylon after a Gale     

Dorothy Lee Richardson 《The Educational forum》2013,77(3)

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Back to the Future?     

Dr Celia Whitchurch  Professor Lee Harvey 《Higher Education Quarterly》2012,66(1):1-2

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Breakfast alone     

Marion H. Lee 《Communication quarterly》2013,61(2)

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The Best 100 Free Apps for Libraries by Jim Hahn     

Bradford Lee Eden 《Public Services Quarterly》2013,9(2):124-125

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The Politics of Cultural Practice: Thinking through Theatre in an Age of Globalization by Rustom Bharucha     

Lee Weng Choy 《Inter-Asia Cultural Studies》2013,14(2):321-324

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Neuroimaging Studies of Reading Development and Reading Disability     

Kenneth R. Pugh  W. Einar Mencl  Annette R. Jenner  Jun Ren Lee  Leonard Katz  Stephen J. Frost  Sally E. Shaywitz  Bennett A. Shaywitz 《Learning disabilities research & practice》2001,16(4):240-249

Converging evidence from a number of neuroimaging studies, including our own, suggest that fluent word identification in reading is related to the functional integrity of two left hemisphere posterior systems: a temporo-parietal system and a ventral occipito-temporal system. These posterior systems are functionally disrupted in developmental dyslexia. Reading disabled, relative to nonimpaired, readers demonstrate heightened reliance on both inferior frontal and right hemisphere posterior regions, presumably in compensation for the LH posterior difficulties. We propose a neurobiological account suggesting that for normally developing readers the temporo-parietal system predominates at first, and is associated with aspects of processing critical in learning to integrate orthography with phonological and lexical-semantic features of printed words. The occipito-temporal system, by contrast, constitutes a fast, late-developing, word-identification system that underlies fluent word recognition in skilled readers.  相似文献   

Effective multi‐agency partnerships – putting Every Child Matters into practice     

Peter Lee 《欧洲师范教育杂志》2009,32(4):489-490

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Embellishing Problem-Solving Examples with Deep Structure Information Facilitates Transfer     

Hee Seung Lee  Shawn Betts  John R. Anderson 《Journal of Experimental Education》2017,85(2):309-333

Appreciation of problem structure is critical to successful learning. Two experiments investigated effective ways of communicating problem structure in a computer-based learning environment and tested whether verbal instruction is necessary to specify solution steps, when deep structure is already embellished by instructional examples. Participants learned to solve algebra-like problems and then solved transfer problems that required adjustment of learned procedures. Experiment 1 demonstrated that verbal instruction helped learning by reducing learners' floundering, but its positive effect disappeared in the transfer. More importantly, students transferred better when they studied with examples that emphasized problem structure rather than solution procedure. Experiment 2 showed that verbal instruction was not necessarily more effective than nonverbal scaffolding to convey problem structure. Final understanding was determined by transparency of problem structure regardless of presence of verbal instruction. However, verbal instruction had a positive impact on learners by having them persist through the task, and optimal instructional choices were likely to differ depending on populations of learners.  相似文献