裂叶苣荬菜的化学成分研究

从菊科裂叶苣荬菜的干燥全草中分得2个黄酮化合物,经理化常数测定及光谱分析鉴定为洋芹素和木犀草素-7-O-葡萄糖甙。     

液膜法提取硝酸水溶液中Ag~+的工艺过程

液膜的组成为:2%石油硫醚-4%多丁二酰亚胺-94%煤油,内相试剂为:1～2mol/L的氨水溶液。较为适宜的操作条件为:乳水比为1:3;内油比为0.8:1;外相硝酸浓度为0.5～1mol/L;常温操作。当料液中的银离子浓度小于800ppm时,一次提取率可达97%以上。本工艺具有分离速度快,效率高、选择性好等优点。     

Visualization of patent foramen ovale by biplanar transesophageal echocardiography

Summary It is difficult for conventional transthoracic echocardiography (TTE), by which precise and accurate images of interatrial septum (IAS) can not be acquired, to diagnose patent foramen ovale (PFO) clearly. To evaluate the diagnostic value of biplanar transesophageal echocardiography (TEE) for PFO, TTE and biplanar TEE were performed simultaneously in 270 patients. It was found that in 7 patients patent foramen ovale was detected only through longitudinal planes of biplanar TEE. IAS, which consists of primitive septum and membrane of fossa ovalis, can be directly visualized by two-dimensional images of TEE; in patients with PFO, a dull color flow, which shunts from the right atria to the left atria through the gap between primitive septum and fossa ovalis, can be detected by color Doppler flow images. Furthermore, some right-to-left shunting microbubbles through the valve of patent fossa ovalis can be discovered by cardiac acoustic contrast echocardiography. In conclusion, biplanar TEE combined with color Doppler image and cardiac acoustic contrast facilitates a definite diagnosis of patent foramen ovale as the excellent anatomic images of IAS can be obtained from multiple views under this kind of performance.     

线性变温法研究硫酸链霉素粉针剂的稳定性

用线性变温法对硫酸链霉素粉针的稳定性进行了测定,得出25℃时的降解反应速度常数 k_(25)为1.744×10~(-6)h~(-1)、化学反应的表观活化能为107.9kJ/mol,25℃时贮存的 t_(0.9)为6.9年。     

某部队急性腹泻病监测报告 Ⅰ.流行病学部分

１９９１年６月～１９９２年５月在驻粤某部队进行了急性腹泻病的主动监测。年发病率为０．６４～１．０次／人／年。发病率与相对湿度（Ｘ２）、气温（Ｘ３），特别是雨量（Ｘ１）的关系经多元回归分析表明呈正相关。ｙ＝１．９８＋０．０２ｘ１＋０．０２ｘ２＋０．０７ｘ３，ｒ＝０．８７２７，Ｐ＜０．０１。病例－对照研究结果提示，饭前、便后不洗手等生活习惯用腹泻发病有密切关系。２６．３％的患者有淋雨、腹部受凉或感冒等     

Chemical Pathways of Peptide Degradation. V. Ascorbic Acid Promotes Rather than Inhibits the Oxidation of Methionine to Methionine Sulfoxide in Small Model Peptides

The effect of primary structure and external conditions on the oxidation of methionine to methionine sulfoxide by the ascorbate/Fe³⁺ system was studied in small model peptides. Degradation kinetics and yield of sulfoxide formation were dependent on the concentration of ascorbate and H⁺, with a maximum rate observed at pH 6–7. Phosphate buffer significantly accelerated the peptide degradation compared to Tris, HEPES, and MOPS buffers; however, the formation of sulfoxide was low. The oxidation could not be inhibited by the addition of EDTA. Other side products besides sulfoxide were observed, indicating the existence of various other pathways. The influence of methionine location at the C terminus, at the N terminus, and in the middle of the sequence was investigated. The presence of histidine in the sequence markedly increased the degradation rate as well as the sulfoxide production. The histidine catalysis of methionine oxidation occurred intramolecularly with a maximum enhancement of the oxidation rate and sulfoxide production when one residue was placed between the histidine and the methionine residue.     

豆渣纤维的降脂作用及对血液流变学影响的研究

以ＳＤ大鼠为对象，研究了豆渣纤维对高胆固醇膳动物脂质代谢和血流变性的影响，并与果胶和纯纤维素进行比较，结果表明：８周实验后，豆渣与果胶组动物的血清总胆固醇（ＴＣ）和低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）显著降低，但豆渣组的血脂水平比果胶组更低（Ｐ＜０．０５）。而纯纤维素组未显出降脂作用。各组大鼠的甘油三醋（ＴＧ）和高密度脂蛋白胆固醇（ＨＤＬ－Ｃ）也无明显变化。实验同时表明，６％的豆渣纤维与果胶均可使高脂大鼠的血粘度及血小板聚集率降低（Ｐ＜０．０５），且前者优于后者。相关分析显示，血脂与血流变学指标间存在显著相关性（Ｐ＜０．０５），其中ＴＣ与ＬＤＬ－Ｃ是影响血流变性的重要因素。６％的以上各种纤维摄入量均不影响大鼠的摄食量与生长。     

侧脑室－头静脉分流术治疗梗阻性脑积水

通过对２５例成人尸体的解剖学调查及应用＂侧脑室─头静脉分流术＂治疗２３例梗阻性脑积水的临床疗效观察，旨在确立一种脑积水症手术分流的新途径。２３例手术病人显效率９２％（２１／２３）。１８例（７８％）基本恢复正常。３例（１３％）明显好转。２例轻度改善。分析表明：头静脉具备位置浅表恒定、管径适宜、瓣膜可防止血液返流等解剖学特点。是一条可供选择的较为理想的脑积水症分流途径。     

尿中糖胺多糖总量的测定方法

本文采用原子吸收的方法测定样品中糖胺多糖的含量。此法的灵敏度为0.102μg/ml,样品中铜检出值的变异系数为9％,平均回收率为103％,因此认为本方法的灵敏度、精密度和准确度都较高。此外,样品中存在的铜和葡萄糖对本实验均无干扰作用。