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

是存在于DNA与RNA中含氮碱基，具有个嘌呤环结构。

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

这样可以氧气取之前被氮气占据肺泡。

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

性状本品系大麦提取水，于配制真菌培养基，提供碳水化合及氮源。