Guanine A nitrogenous base found in DNA and RNA.Guanine has a pruine ring structure.

是存在于DNA与RNA中的一种含氮碱基，具有一个嘌呤。

Preoxygenation replaces the primarily nitrogenous mixture of ambient air, which constitutes the patient's functional residual capacity, with oxygen.

这样可以用氧气取之前被氮气占据的。

Malt extract is made by extracting the soluble products from sprouted grain,used in mycological as a source of carbohydrate and nitrogenous.

状本品系大麦提取的水溶物，用于配制真菌培养基，提供碳水化合物及氮源。