紫外分光光度法测定背景未知的复方制剂组分

本文利用目标转换因子分析中具有使纯组分光谱可向自身逼近的性质,提出了一种迭代目标转换因子分析算法,用于寻找未知背景光谱.通过在复方扑热息痛注射液分析中的应用,扑热息痛和安替比林的平均回收率均为100.0％,变异系数分别为1.1％和1.0％。结果表明本法为含有未知背景的多组分体系的紫外分光光度分析提供了可行的途径。     

药物气相色谱分析专家系统

介绍了药物气相色谱专家系统。该系统共包括六个主要模块:知识库、推理机构、人机接口、知识获取、动态数据库、色谱优化,有分离模式选择、柱系统推荐、知识获取、色谱条件优化等功能。作者用TurboProlog语言,用产生式规则的知识表达方式和正向推理策略在IBMPC/XT机上编程序实现了这一系统。     

Monocyte adhesion to subendothelial components

Human monocytes have been shown to penetrate the endothelial layer of large blood vessels and to adhere to the subendothelial basement membrane. To determine the active components of this process, we have studied the ability of monocytes to adhere to isolated components of the subendothelial matrix. Using a quantitative dot-blot adhesion assay, we find that monocytes adhere preferentially to immobilized laminin and elastin. The monocytes adhere less well to fibronectin and bind poorly or not at all to collagen types I and IV, or to heparan sulfate. Monocyte binding to elastin requires an intact, crosslinked molecule as no binding was observed to soluble, acid-alcohol elastin extracts, to pepsin or elastase digests of elastin, to tropoelastin monomer, or to desmosine/isodesmosine crosslinks. Similar binding profiles to elastin, laminin, and fibronectin were seen with the established human leukocyte cell line U937. The promyelocytic cell line HL60 adhered equally well to laminin but showed slightly reduced adhesion to elastin when compared with the fresh monocytes or U937 cells. Freshly isolated human erythrocytes did not demonstrate significant adhesion to fibronectin, laminin, or elastin.     

卡尔曼滤波分光光度法同时测定复方降压片中六种组分的含量

近年来,计算分光光度法得到了迅速的发展,有关各种新方法应用的报道层出不穷,如最小二乘法、线性规划、卡尔曼滤波、因子分析及P-矩阵法等,使得以往用经典分析方法难以测定的复方制剂问题能够在数学及微机的辅助下得以解决。但迄今为止,同时测定的组分数目一般均小于或等于四个,本文应用卡尔曼滤波法未经分离直接同时测定复     

Surface coil MR imaging of abdominal viscera. Part I. Theory, technique, and initial results

Prototype surface coil magnetic resonance (MR) images were obtained from phantoms and 42 subjects at 0.6 T to assess the feasibility of imaging relatively deep abdominal structures. Surface coil images demonstrated a two- to fourfold improvement in signal-to-noise ratio (SNR) when compared with whole-body coil images with the same resolution elements. This improvement in SNR allowed us to obtain images with thinner sections, higher in-plane resolution, or, alternatively, a decrease in image time. Compared with body images, surface coil images demonstrated greater anatomic detail and reduction in motion artifacts. Despite the limited field of view in very large patients, the use of surface coils improves the diagnostic capability of MR imaging of the abdomen.     

Magnetic resonance imaging and spectroscopy of hepatic iron overload

Experimental animals that had been given excess iron in their diet were studied by magnetic resonance (MR) imaging in vivo and by magnetic resonance (MR) spectroscopy in vitro. Hepatic iron overload in patients with transfusional iron excess was studied by MR imaging, and isolated iron protein fractions were studied in vitro by MR spectroscopy. The spin echo image intensity of livers with iron overload was decreased because of the extreme decreases in T2 compared with normal; T1 was decreased only moderately. The relaxation rates 1/T2 and 1/T1 both showed a linear relationship to hepatic iron levels. Ferritin solutions showed moderate decreases in T2 and mild decreases in T1. The T2 relaxivity of ferritin, which is due to the iron core rather than the apoferritin protein shell, does not appear sufficient to account for the extreme decrease in T2 observed in hepatic iron overload. Low molecular weight cytosol iron is present in lower concentrations than ferritin but potentially has much greater relaxivity and may contribute to the MR findings. These techniques may be useful in other studies of iron metabolism.