题 目：人体食管的层状结构、方向性和时间依赖力学行为的表征（Characterisation of the layer, direction and time-dependent mechanical behaviour of the human oesophagus）
时 间：2023年5月5日10：30－12：00
地 点：交通大楼604会议室
报告人：Mokarram Hossain博士（英国斯旺西大学）
欢迎广大师生参加
土木与交通学院
2023年4月23日
报告人简介：
Dr Mokarram Hossain is an Associate Professor at the Zienkiewicz Centre for Computational Engineering (ZCCE) at Swansea University. His research interests lie in the wide and interdisciplinary areas of soft polymeric and active multifunctional materials ranging from material synthesis, experimental study to computational modelling. He has numerous fundamental and cutting-edge contributions in the areas of polymer curing modelling, electro-active, magneto-active polymers, hydrogel experiments and modelling. He has obtained several research grants including from UK Research Council (EPSRC), Royal Society and industries for energy harvesting, soft material characterisations using electro-active/ magneto-active polymers. Dr Hossain obtained the best Postdoc Paper Prize from the UK Association for Computational Mechanics (UKACM). He was a Mercator Fellow from Gerrnan Science Foundation (DFG) and ASEM-DUO Fellow from South Korea. Dr Hossain published more than 90 peer reviewed journal papers in many leading journals across disciplines of materials, mechanics and computations including JMPS, CMAME, NPJ Nature Computational Materials, Applied Materials Today, Renewable Energy Reviews.
报告摘要：
The oesophagus is a primarily mechanical organ in the human body. The mechanical characterisation of the oesophagus is essential for applications such as medical device design, surgical simulations and tissue engineering, as well as for investigating the organ’s pathophysiology. However, the material response of the oesophagus has not been established in regard to the more complex aspects of its mechanical behaviour using fresh, human tissue: as of yet, in literature, only the hyperelastic response of the intact wall has been studied. Therefore, in this study, the layer-dependent, anisotropic, visco-hyperelastic behaviour of the human oesophagus was investigated through various mechanical tests. For this, cyclic tests, with increasing stretch levels, were conducted on the layers of the human oesophagus in the longitudinal and circumferential directions and at two different strain rates. Additionally, stress relaxation tests on the oesophageal layers were carried out in both directions. Overall, the results show discrete properties in each layer and direction, highlighting the importance of treating the oesophagus as a multi-layered composite material with direction-dependent behaviour. Previously, the authors conducted layer-dependent cyclic experimentation on embalmed human oesophagi. A comparison between the fresh and embalmed tissue response was carried out and revealed surprising similarities in terms of anisotropy, strain-rate dependency, stress-softening and hysteresis, with the main difference between the two preservation states being the magnitude of these properties. As formalin fixation is known to notably affect the formation of crosslinks between the collagen of biological materials, the similarities may reveal the influence of cross-links on the mechanical behaviour of soft tissues.
