In this Article. In this Article. A solitary pulmonary nodule (SPN) is a single abnormality in the lung that is smaller than 3 cm in diameter. Generally, a pulmonary nodule must grow to at least 1 cm in diameter before it can be seen on a chest X-ray.
Osmosis is the scientific process of transferring fluid between molecules. When molecules move in and out of a cell to achieve the same concentration of something, like salt, on both sides, then osmosis is happening.
Osmosis is the net moveme â¦ nt of water molecules from higher concentration gradient to a lower concentration gradient through a partially permeable membrane So the difference is that diffusion involves movement of any particles/ substance (e.g. solid, liquid, gas) while osmosis can only occur with water.