基于短波近红外光谱盐酸氟桂利嗪粉末药品质量比的估算方法

基于短波近红外(SW-NIR)漫反射光谱,提出一种非破坏定量预测盐酸氟桂利嗪粉末药品质量比的新方法.以高效液相色谱法(HPLC)分析值为参考值,将遗传算法(GA)和神经网络相结合,建立盐酸氟桂利嗪粉末药品的光谱特性与质量比间的定量分析模型.应用GA自动构建神经网络拓扑结构,选择最优的网络参数和光谱波段;讨论不同光谱预处理方法对神经网络预报能力的影响,并对测试集样品质量比进行预测.结果表明,一阶导数数据预处理方法为最优预处理建模方法,其测试集的均方根误差RMSE=0.198 7%,相关系数R=0.986 3.     

Enhanced reactivity towards flunarizine in cerebrovascular bed of spontaneously hypertensive rats

Summary Cerebral blood flow (CBF) was measured and cerebrovascular resistance (CVR) was calculated in anesthetized spontaneously hypertensive rats (SHR) and normotensive rats (NR) following the administration of incremental dosages of i.v. flunarizine or papaverine. CBF and CVR changes following papaverine were the same in both groups of rats irrespective of the dose of the drug. The effect of flunarizine was much more pronounced in SHR than in NR. The results point out the greater dependency of basal cerebrovascular tone in SHR upon Ca²⁺ influx into vascular smooth muscle cells.     

侧脑室注射氟桂嗪对马桑内酯诱发大鼠皮层和海马痫样放电的抑制作用

采用皮层应用马桑内酯的方法致痫大鼠，观察侧脑室注射钙通道阻滞药氟桂嗪对致痫动物皮层脑电图、海马电图和皮层诱发电位的影响。结果显示，马桑内酯致痫时，皮层脑电图、海马电图发生痫样放电，皮层诱发电位呈高振幅变化。侧脑室注射氟桂嗪能明显地抑制致痫大鼠皮层诱发电位的振幅和脑电图、海马电图痫样放电。结果提示，氟桂嗪的抗癫痫作用与抑制中枢神经元Ｃａ＾２＋内流有关。