A New Asterosaponin from the Starfish Culcita novaeguineae

A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.     

轻希土硫氰酸盐与2, 3, 11, 12, -四苯基-1, 4, 7, 10, 13, 16-六氧-2, 11-十八环二烯配合物的合成及XPS研究

合成了六种轻希土硫氰酸盐与标题不饱和冠醚的新固体配合物,进行了元素分析,摩尔电导率、DTA、UV、IR和XPS等表征.对Ln(NCS)₃·L和Ln(NCS)₃的XPS研究中,得到它们组成原子芯能级电子(Ln3d_5/2,Ols,Nls,S2p)的结合能信息;观察到除Y3d_5/2外Ln3d_5/2(Ln=La、Ce、Pr、Nd、和Sm)的伴峰结构,Ln3d_5/2结合能与原子序数呈线性关系,并推断类似化合物Pm³d_5/2结合能在1035eV附近.     

一种新型联萘基旋光共轭聚合物的圆二色谱和圆偏振荧光光谱

众所周知 ,聚合物的光电性质依赖于聚合物链的构象和 (或 )组成 ,通过在聚合物上引入手性单元 ,采用圆二色谱 ( CD)和圆偏振荧光光谱 ( CPL)等方法可表征聚合物结构 [1] .近年来 ,由于圆偏振光可用作光数据存储和液晶显示器背景光 [2 ] ,人们开始注重共轭聚合物圆偏振光材料的研究 .共轭聚合物的光致和电致圆偏振光的现象由一种带手性侧链的聚噻吩[3 ] 和一种带手性侧链的聚 (对苯撑乙烯 ) [4 ]产生 ,但它们的圆偏振荧光度 (用不对称因子 glum=2 ( IL-IR) / ( IL+IR)表示 ,IL 和 IR 分别指左圆偏振光强度和右圆偏振光强度 )相对较低 …     

对硝基苯磺酰基乙酸酯与α，β－不饱和酸酯类化合物在固液相转移条件下的反应

在固液相转移催化（Ｋ_２ＣＯ_３／ＤＭＦ／ＴＥＢＡ）条件下，对硝基苯磺酰基乙酸酯与α，β－不饱和酸酯反应意外地生成加成重排产物［如生成２－甲基－２－（对硝基苯基）戊二酸－１－甲酯－５－乙酯］。其反应机理可能是砜酯首先与α，β－不饱和酯起Ｍｉｃｈａｅｌ反应，随后加成物发生分子内芳环上的亲核性取代，酸化后脱去ＳＯ２得最终产物。     

乳液聚合法制备水分散有机硅聚合物

乳液聚合法是制备水性有机硅聚合物的最有效、最常用的方法。本文从乳液聚合所采用的有机硅单体或预聚物、乳液聚合工艺、乳液体系的稳定性等方面，论述了采用乳液聚合法合成水性有机硅聚合物领域所面临的问题及所取得的研究进展。     

氧化钨薄膜微型电化学器件的研究

本文论述了WO_3薄膜氢离子敏器件的结构、原理、制备技术和测试分析。利用WO_3薄膜在H+溶液中由绝缘转化为导电特性,成功地研制成氢离子敏器件。这是一种简易而经济的微型pH敏器件技术。     

Study of urinary nucleosides as biological marker in cancer patients analyzed by micellar electrokinetic capillary chromatography

Thirteen normal and modified nucleosides, primarily degradation products of transfer ribonucleic acid (tRNA), were evaluated as potential tumor markers for cancer patients. Their urinary concentrations were determined by means of micellar electrokinetic capillary chromatography (MEKC) in the urine from 54 healthy adults and 70 cancer patients, then quantitatively expressed as a function of creatinine excretion. It was found that urinary nucleosides for cancer patients were on the average significantly higher than those for healthy controls, however, no significant differences were found between male and female or between different ages. Based on 13 urinary nucleoside concentrations, principal component analysis (PCA) could be used to classify 72% of cancer patients from the healthy controls. The present study shows that the precise measurement of urinary nucleosides by MEKC in combining with PCA technique may provide a clinically useful approach for diagnosis of cancer.     

Correlation between Site ll-Specific Human Serum Albumin (HSA) Binding Affinity and Murine in vivo Photosensitizing Efficacy of Some Photofrin Components

Human serum albumin (HSA) is one of the key components in human blood that may influence drug distribution. As such, it is important to know the affinity of any drug for albumin. Previously, Photofrina mixture of monomeric, dimeric and oligomeric porphyrins, has been subjected to HSA binding studies. However, due to its complex nature, binding studies on Photofrin or other hematoporphyrin derivatives with HSA are inconclusive. In this report, the binding properties of some components (dimers and trimers) of Photofrin® and the relationship between murine photosensitizing efficacy and those binding properties were investigated. The interaction of these porphyrins with HSA was investigated by direct ultrafiltration and fluorescent titration techniques with fluorescent probes such as dansyl-L-proline (DP), which is known to interact selectively with site II on HSA. Porphyrins also were tested for antitumor activity in a mouse model following intravenous administration and exposure to laser light. Together, the results suggest that the photosensitizers that were preferentially bound to site II of HSA were most effective at controlling murine tumor regrowth     

Decomposition of Transformer Oil Under Ultrasonic Irradiation During Degassing Process

In the degassing process of transformer oil with ultrasonic waves ,decompostition of the oil was observed.Light hydrocarbons,including methane,ethane,ethylene ,aceylene,propane etc,were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field ,The gases came from decomposition of hydrocarbon molecules under cavitation effect.     

The embedding theorem in limiting cases and its applications in singular perturbation

In 1980, Brézis^[6], using the technique of dividing the total space into two parts, proved the embedding theorem of limiting case which is very important in applications. In 1982, Ding Xiaqi improved the proof given in [6], by using of the technique of dividing the total space into three parts. In this paper, using the technique of dividing the total space into three parts, the author proves uniformly the results obtained by Ding^[3,4], and gives an embedding theorem of limiting case including (Lemma 2.2). And he also gives two kinds of examples, applying the embedding theorems (limiting case and non-limiting case) and the interpolation theorems. These examples are the singular perturbation problems in the sense of Lions^[1] (for the definition of singular perturbation, see [1], Introduction). But the singular solutionU _e converges uniformly to the limit solution (degenerate)U, ase0.