在相交的细胞层中,应力形状的错位
Mehrana R Nejad1, Liam J Ruske2, Molly McCord3,4
1The Rudolf Peierls Centre for Theoretical Physics, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom. mehrana@g.harvard.edu.
Nature communications
|April 29, 2024
概括
细胞可以在组织形成过程中独立于它们的形状控制它们的收缩力. 这一发现挑战了以前关于细胞机制的假设,并为组织修复和发育提供了新的见解.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 发育生物学是发展生物学.
背景情况:
- 表皮细胞产生活力,这对于组织的形成和修复至关重要.
- 人们普遍认为,细胞收缩应力与细胞体方向保持一致.
研究的目的:
- 研究细胞形状和细胞产生的收缩应力之间的关系.
- 为了确定细胞收缩应激是否可以从细胞体方向脱.
主要方法:
- 同时测量细胞形状和细胞产生的收缩应力方向.
- 开发一个连续模型来分析压力和细胞体动态.
主要成果:
- 观察到的动态域,其中收缩应力系统地与细胞体方向不一致.
- 开发的连续模型成功地复制了应力错位的实验空间和时间动态.
- 证明细胞控制收缩力独立于细胞形状.
结论:
- 细胞收缩力与细胞形状没有刚性结合.
- 这种脱表明,控制细胞力量生成和细胞形状的物理规则具有更大的灵活性.
- 这些发现对理解组织形态发生和修复机制具有重要意义.
相关概念视频
Stress: General Loading Conditions
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To grasp the intricacy of real-world conditions where multiple loads are applied simultaneously to a structure, one might visualize a section passing through a specific point within a body, aligned parallel to the xy plane. This section is subjected to various forces, including original loads, normal forces, and shearing forces.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes....
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes....
307
Stress Concentrations
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Stress concentration is when stress intensifies near discontinuities such as holes or abrupt cross-sectional changes in a structural member. This localized stress can often surpass the average stress within the member. The stress distribution in flat bars, either with a circular hole or varying widths connected by fillets, can be determined experimentally using a photoelastic method. The results are based on ratios of geometric parameters like the ratio of the hole's radius to the smaller...
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Components of Stress
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Stress analysis under multiple loading conditions is intricate, necessitating a comprehensive grasp of normal and shearing stresses. Consider a small cube at point O, subjected to stress on all six faces, visible or not. Normal stress components σx, σy, σz act perpendicularly to the x, y, and z axes. Shearing stress components τxy and τxz are exerted on faces perpendicular to these axes.
Interestingly, the hidden cube faces also experience these stresses, equal and...
Interestingly, the hidden cube faces also experience these stresses, equal and...
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General State of Stress
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The general state of stress within a material can be accurately depicted using a stress tensor. This tensor encapsulates the internal forces distributed within a material subjected to external forces or deformations.
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Specifically, consider a tetrahedral element where one face, labeled XYZ, is perpendicular to the line OA, and the remaining faces align with the coordinate axes with point O as the origin. At any point, such as point O, the stress tensor can be used to determine the stress...
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Principal Stresses
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The graphical depiction of normal and shearing stress equations is represented by a circle, demonstrating the interplay between these stresses under different angular conditions. The center of this circle C, located on the vertical axis, represents the average normal stress, while its radius shows the range of stress variations. At points A and B, where the circle intersects the horizontal axis, the maximum and minimum normal stresses are observed, occurring without shearing stress. These...
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Studying stress transformation is essential in understanding how stress components within a material, like a cube under plane stress, change with rotation. This change is analyzed by considering a prismatic element within the cube. As the element rotates, the stress components acting on it—both normal and shearing stresses—change in magnitude and orientation. This change is quantified using trigonometric functions of the rotation angle, relating the forces acting on the rotated element's...
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