Riesling grapes are naturally very high in acid, and the cool, northern climate of Germany means this ripping acid stays in the grapes even into the fall harvest season. So winemakers let the fermentations stop before the wine is completely dry, retaining a little sweetness in order to strike balance in the wine.
Oxygenation refers to the process of adding oxygen to the body system. There is no way to reliably measure arterial oxygenation via clinical signs alone. Cyanosis, pallor and other physical findings are not reliable.
Oxygenated blood is blood in which oxygen is attached to the haemoglobin molecules in the red blood cells. It is bright red because the attached oxygen makes the normally blue haemoglobin molecules turn red. When blood has delivered oxygen to the cells, it is described as deoxygenated.