在Passiflora caerulea的卷轴中产生力
Frederike Klimm1,2,3,4, Thomas Speck1,2,3,4, Marc Thielen1,2,3
1Plant Biomechanics Group @ Botanic Garden, University of Freiburg, Schänzlestraße 1, D-79104, Freiburg, Germany.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
|August 6, 2023
概括
爬行植物的子形成螺旋弹,产生紧张力,这对于基板的附着至关重要. 这种绕机制涉及两个阶段:初始的木质化取决于水的状态,其次是稳定永久功能.
科学领域:
- 植物生物学 植物生物学
- 生物力学 生物力学
- 材料科学是一种材料科学.
背景情况:
- 爬行植物利用子作为支,把它们卷成螺旋弹.
- 这些子产生显著的张力,用于附着.
研究的目的:
- 研究爬行植物棘中螺旋弹形成的机制.
- 确定螺纹所产生的力及其对水分的依赖.
主要方法:
- 在Passiflora caerulea的实地力测量.
- 肌结构的解剖学研究.
- 脱水-再水实验在部段和性组织上.
主要成果:
- 肌卷轴产生6-140mN的力,足以固定基板.
- 生成的力与植物水的状态有很强的相关性.
- 提出了形成弹的两相机制,涉及单边,然后是完全的中央化.
结论:
- 螺旋弹的形成是一个两相的过程:一个依赖流的卷轴阶段和一个依赖水的稳定阶段.
- 单边双层收缩是卷轴的潜在驱动力.
- 化确保了骨的弹功能,而不管水分.
相关概念视频
01:14Generation of Straight or Branched Actin Filaments
2.9K
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
2.9K
01:17Force On A Current Loop In A Magnetic Field
3.3K
Magnetic forces on wires carrying current are most frequently applied in motors. A DC motor is a device that converts electrical energy into mechanical work. In motors, wire loops are enclosed in a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate. The direction of the current is reversed once the loop's surface area is lined up with the magnetic field, causing a constant torque on the loop. During the process,...
3.3K
01:06Centrifugal Force
2.9K
Pseudo forces, or fictitious forces, appear to act on an object in motion in a rotating frame of reference with respect to an inertial reference frame. These forces are not real forces but rather mathematical constructs and are introduced to simplify calculations in a non-inertial frame while using Newton's laws of motion. Common examples of pseudo forces include centrifugal, Coriolis, and Euler forces. These forces are essential in fields such as mechanics, astrophysics, and fluid...
2.9K
01:22Magnetic Force On Current-Carrying Wires: Example
1.5K
In a magnetic field, moving charges encounter a force. If a wire contains these moving charges, i.e., if the wire is carrying a current, then a force acts on the wire as well. Consider a pair of flexible leads holding a wire that is 40 cm long and 10 g in weight in a horizontal position. The wire is placed in a constant magnetic field of 0.40 T, as shown in Figure 1(a). Determine the magnitude and direction of the current flowing in the wire needed to remove the tension in the supporting leads.
1.5K
01:39Mechanism of Filopodia Formation
2.4K
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
2.4K
01:23Coriolis Force
3.6K
An accelerating particle experiences a force equal to the mass multiplied by the acceleration in an inertial frame of reference. Consider a particle in a non-inertial frame of reference, such as a sliding ball on a rotating table. The acceleration of the ball in this rotating reference frame is different than in the intertial frame, which modifies its equation of motion. The fictitious forces acting additionally on a rotating frame of reference alter Newton's Second Law expression.
3.6K