当细菌与药物作用一段时间后,药物浓度低于最小抑菌浓度时,仍然对细菌的生长繁殖继续有抑制效应,此称为
A. 后遗效应
B. 继发效应
C. 特异质反应
D. 抗菌后效应
E. 变态反应
某弱酸性药物的PKa是3.4,在血浆中的解离百分率约为
A. 1%
B. 10%
C. 90%
D. 99%
E. 99.99%
A shop foreman determines that an employee would produce two more units of output ff he worked one additional hour. The product currently sells for $15.00 per unit and the firm is a price taker. Which of the following choices most accurately describes the relationship between the marginal revenue (MR) and marginal revenue product (MRP) from the additional hour of labor input
A. MRP > MR.
B. MRP = MR.
C. MR < $15 and MRP = MR.
关于多西环素的错误叙述是
A. 口服吸收快而完全
B. 抗菌作用较四环素强
C. 不易透过血脑屏障
D. 作用持续时间较四环素长
E. 可用于肾功能不良患者