Many common materials exhibit a mixture of specular and diffuse reflection. Water and carbon dioxide from the interstitial fluid diffuse into the epithelial cells. Inert gas can diffuse into bubble nuclei between tissues. Sarcoidosis of the scalp presents with diffuse or patchy hair loss. Diffuse and nodular are similar in behavior. A matte surface will diffuse the reflected light and have a more even colour range. Certain types of lupus nephritis such as diffuse proliferative glomerulonephritis require intermittent cytotoxic drugs. Solar insolation is made up of direct, diffuse, and reflected radiation. Chronic sarcoid arthritis usually occurs in the setting of more diffuse organ involvement. The membrane alone has a hydrophobic core through which polar or charged molecules cannot diffuse. Oxygen can easily diffuse through the red blood cell's cell membrane. Concussion is considered a mild form of diffuse axonal injury. Large, dark, diffuse dark streaks. However most organic solvents will diffuse into the material and cause it to swell. At low cell density, the molecules may just diffuse away.