β-内酰胺类抗生素的构效关系与哪项不符 A. β-内酰胺环是抗菌作用的必要结构,β-内酰胺环并合六元的氢化噻嗪环可显著提高抗菌活性 B. 6-氨基或7-氨基的酰化侧链影响抗菌强度,抗菌谱,耐青霉素酶及耐酸性 C. 侧链中引入吸电子基团将增强对酸的稳定性 D.侧链中引入体积较大基团可增强对青霉素酶的稳定性 E.头孢菌素类的3-位取代基的改变,主要影响化合物的药物动力学特性
【简答题】阅读理解 The 'aha moment'(顿悟时刻) for Arjun Nagendran came one recent afternoon while he was cleaning up the muddy paw prints, and his pet dog, Rocky, was tracking across the house 'again'. 'Why not make sh...