MRI.

PubMed
概括

这项研究引入了一种新的扩散MRI方法,用于非侵入性地测量髓化轴突直径. 模拟证实了其在体内应用的准确性,为临床使用铺平了道路.

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Diffusion01:12

Diffusion

Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...
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Diffusion01:21

Diffusion

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Water and Mineral Acquisition02:34

Water and Mineral Acquisition

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Nervous Tissue: Myelin01:25

Nervous Tissue: Myelin

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Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion

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Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
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