Scroll Wave Dynamics in Heterogeneous Reaction-Diffusion Systems

非均相反应扩散系统中的涡旋波动力学

• 批准号: 1213259
• 负责人: Oliver Steinbock
• 金额: $ 39.52万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1213259&HistoricalAwards=false
• 关键词: Scroll; Wave; Dynamics; Heterogeneous; Reaction

In this award, funded by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, the research group of Professor Oliver Steinbock (Florida State University, FSU) will investigate self-organizing wave patterns in autocatalytic reaction-diffusion systems. These far-from-equilibrium systems are a treasure trove for 21st century science. They create intricate regulatory networks, exhibit fascinating dynamics, and generate information-relaying patterns that one typically expects to find only in biology. The project focuses on understudied processes in three-dimensional excitable media and specifically on rotating scroll waves. These dissipative structures are formed by propagating regions of autocatalytic activity and trailing "refractory zones" of high inhibitor concentration. The primary goal is to establish a complete description of vortex pinning and vortex unpinning in three-dimensional excitable systems. An important example is the distinction between true pinning to small heterogeneities and mere surface termination of the vortices' rotation backbone. Experiments will include weakly excitable, curved, and moving heterogeneities that should allow the active repositioning and reshaping of scroll waves. These challenging studies can be pursued using photochemical methods and/or computer-controlled motion of solid objects. The latter approach will induce fluid flow in the reactive solution but should not affect pattern stability below threshold values that the will be characterized systematically during the project. If successful, these studies will also provide a novel approach to chemo-hydrodynamic systems. Another goal is to demonstrate and analyze the unpinning of scroll rings from heterogeneities in BZ-gel systems using externally controlled electric fields and temperature gradients. The project will test a hypothesis that unpinning can proceed via tilting of the scroll ring relative to the pinning, torus-shaped anchor or alternatively via radial expansion. These investigations will be complemented by kinematic modeling efforts and computational studies of three-dimensional reaction-diffusion models. Much of the chemical research under this project is motivated by the self-organization of living systems. A striking example is the motion of electrical patterns in the human heart that orchestrate the healthy or disturbed pump action of this vital organ. Spinning, vortex-like states have been linked to tachycardia and ventricular fibrillation with the latter being among the leading causes of death for Americans. Highly reproducible experiments with simpler chemical systems have and will reveal important insights into these states. The research team around Prof. Steinbock will specifically investigate how such vortices are changed, reshaped, and possibly stabilized by less active regions. In the context of the heart such regions correspond to scar tissue caused by traumatic events such as heart attacks. This multi-faceted research is also ideally suited for the modern training of undergraduate, graduate, and postdoctoral students. Furthermore Prof. Steinbock will continue his firm commitment to foster underrepresented groups and participate in mentoring programs that aim to increase their leadership roles in research and academia. Specific activities include the production of videos for FSU's Global Educational Outreach Program and YouTube. In addition, Prof. Steinbock will participate in FSU's Honors Research Program for first-year students and contribute to the "Saturday Morning Physics" lecture series for local pre-college students.

在该奖项中，由化学结构，动力学和机制计划资助，奥利弗·斯坦博克（Oliver Steinbock）教授（FSU，FSU）的研究小组将研究自启动反应扩散系统中的自组织波模式。这些遥远的平衡系统是21世纪科学的宝库。 它们创建了复杂的监管网络，表现出迷人的动态，并产生了人们通常期望仅在生物学中找到的信息宣传模式。 该项目着重于三维激发媒体中的研究过程，特别是旋转滚动波。 这些耗散结构是通过传播自催化活性的区域和高抑制剂浓度的“难治区”的。 主要目标是建立三维兴奋系统中涡流固定和涡旋固定的完整描述。 一个重要的例子是，真正固定到小的异质性与涡流旋转主链的表面终止之间的区别。 实验将包括弱兴奋，弯曲和移动的异质性，这些异质性应允许主动重新定位和重塑滚动波。 可以使用光化学方法和/或固体对象的计算机控制运动进行这些挑战性的研究。 后一种方法将在反应溶液中诱导流体流量，但不应影响低于阈值的模式稳定性，该阈值将在项目期间系统地表征。 如果成功，这些研究还将为化学流动力系统提供一种新颖的方法。 另一个目标是使用外部控制的电场和温度梯度来证明和分析BZ-GEL系统中异质性的滚动环的滚动环。 该项目将检验一个假设，即可以通过固定环，相对于固定，圆环形锚或通过径向扩展来进行滚动环。 这些研究将由三维反应扩散模型的运动学建模工作和计算研究补充。该项目下的大部分化学研究都是由生命系统的自组织动机。一个明显的例子是人心脏中电模式的运动，它策划了这种重要器官的健康或干扰的泵的作用。 旋转，类似涡流状的状态与心动过速和心室纤颤有关，后者是美国人的主要死亡原因之一。 具有更简单的化学系统具有高度可重现的实验，并将揭示对这些状态的重要见解。围绕Steinbock教授的研究团队将专门研究如何改变，重塑这些涡旋，并可能被较低的活跃地区稳定。在心脏的背景下，这种区域对应于由心脏病发作等创伤事件引起的疤痕组织。 这项多方面的研究也非常适合于本科生，研究生和博士后学生的现代培训。 此外，Steinbock教授将继续坚定地承诺培养代表性不足的团体，并参与旨在提高其在研究和学术界领导角色的指导计划。 具体活动包括为FSU的全球教育外展计划和YouTube制作视频。 此外，Steinbock教授还将参加FSU的一年级学生的荣誉研究计划，并为当地的预科学生的“星期六早上物理学”讲座贡献。