CHEMOTHERAPEUTIC POLYMER ⅩⅦ. THE SYNTHESIS AND ANTITUMOR ACTIVITY OF POLYPHOSPHATES CONTAINING BOTH NUCLEIC ACID BASE AND NITROGEN MUSTARD

Seven new polyphosphates containing both nucleic acid base and nitrogen mustard were preparedby reacting the monomers, i.e. 1,3-dihydroxyalkyl-5-fluorouracil(II_(a.,b, g)), 1,3-dihydroxyalkyluracil(II_(c,d)) and 1, 3-dihydroxyalkylthymine (II_(e,f)) with W, N,N-bis(2-chloroethyl)phosphoramide dichlo-ride (I). The monomers and polymers were characterized by ~1H-NMR, IR spectra and elementalanalysis. All of the polymers obtained are soluble in water. The antitumor activity of some of thesepolymers were tested against Ehrlish Ascites in mice. The results showed that the polyphosphatescontaining both 5-fluorouracil and nitrogen mustard exhibit lower toxicity and higher antitumor ac-tivity. The inhibition ratio of the polymer (III_a) is 66%.     

Eu3+-芦丁配合物与DNA 相互作用的电化学和紫外可见吸收光谱研究

在0.1 mol·L-1乙酸缓冲溶液中(pH=5.69), 用电化学方法和吸收光谱法研究了Eu3+-芦丁配合物和小牛胸腺DNA的相互作用. 发现Eu3+-芦丁配合物与DNA通过静电吸引和沟槽键合模式键合. 在玻碳电极上通过循环伏安法和差示脉冲法得到了键合常数(K=1.42×104 mol·L-1)和键合位点数(n=2). 用紫外可见吸收光谱研究了Eu3+和芦丁的相互作用, 以及Eu3+-芦丁配合物与DNA 的相互作用.     

Microwave-assisted Polymerization of ε-Caprolactone with Maleic Acid as Initiator and Drug Release Behavior of Ibuprofen-Poly(ε-caprolactone) System

Poly( ε-caprolactone)(PCL) with weight-average molar mass over 10000g/mol was synthesized by microwave-assisted ring -opening polymerization of ε-caprolactone(ε-CL) with maleic acid(MA) as initiator (2.45GHz,360W,85min),Ibuprofen-PCL controlled release system was prepared directly by the ROP of ε-CL in its mixture with ibuprofen.The release of ibuprofen from the system was sustained and steady.     

THERMAL ACTIVATION OF IMMOBILIZED PAPAIN

Papain (Papainase, EC 3.4.22.2) was immobilized on porous silica beadsby cross linking with glutaraldehyde. The thermal activation of this immobilized papainin aqueous system was found at a temperature range from 50 to 90℃. The higher thetemperature, the more active the immobilized papain will possess. At the same time,the durability of the immobilized papain on heating was greatly improved. The effect ofadditives and salts on the activity of the immobilized papain were also studied. The resultsshowed that the additives and some of the salts studied could markedly enhance the activityof the immobilized papain at elevated temperature.     

NdCl3-CdCl2-HCl-H2O的相平衡及其固相化合物的研究

测定了四元系NdCl₃-CdCl₂-HCl-H₂O(298. 15 K) 的相平衡溶度数据, 绘制了相应的溶度图. 该四元系是由4个固相区CdCl₂•H₂O(原始盐)、9CdCl₂•NdCl₃•20H₂O、5CdCl₂•NdCl₃•13H₂O、NdCl₃•6H₂O(原始盐)组成的复杂体系. 用X射线粉末衍射及TG-DTG和荧光光谱对9CdCl₂•NdCl₃•20H₂O 和5CdCl₂•NdCl₃•13H₂O进行了研究. 荧光研究表明, 化合物9CdCl₂•NdCl₃•20H₂O具有微弱的荧光强度, 5CdCl₂•NdCl₃•13H₂O的荧光强度则相对大于9CdCl₂•NdCl₃•20H₂O的. 对X射线粉末衍射进行了指标化.     

基于软X射线光谱的锂电池材料的电子结构与演变的研究进展

开发新型高能量密度以及低成本的锂离子电池, 是有效应对能源危机和环境挑战的可行路径之一. 锂离子电池材料的电子结构与电子态的演化决定了材料诸多本征性质以及电池综合性能. 探测并操控电极材料电子态的演化对探求电极反应的物理机理、 促进电池材料发展具有重要意义. 基于同步辐射的软X射线光谱技术可以直接探测费米能级附近的电子态. 本文从阴阳离子氧化还原反应的不同角度对利用软X射线光谱对电子态演变的研究进行了总结, 获得了电极材料电化学循环过程中过渡金属与氧的电子态演化信息, 系统阐述并总结了不同锂离子电池材料中电子态的演化以及氧化还原反应机理的最新研究进展.     

离子化合物[2，6-bis(Benzimidazol-2-yl)pyridineH2]2+·[SbCl5]2-的合成、晶体结构及荧光性质

利用邻苯二胺、2,6-吡啶二甲酸与三氯化锑在盐酸溶液中经水热反应,合成了一种新的离子型化合物[2,6-bis(Benzimidazol-2-yl)pyridineH₂]²⁺·[SbCl₅]^2-。通过化学分析、元素分析、热重分析、红外光谱及荧光光谱对结构和性质进行了表征,用X-射线单晶衍射测定了该化合物的晶体结构。化合物的晶体属三斜晶系,P1空间群。Sb³⁺与其周围5个氯离子配位,构成一个畸变四方锥构型[SbCl₅]^2-配位结构,2个配阴离子[SbCl₅]^2-之间通过Sb(1)…Cl(1)^ⅱ次级键形成四元环状结构,并与2,6-二(苯并咪唑-2′)吡啶两价阳离子,通过离子键及氢键形成三维网状离子化合物晶体。该化合物具有很好的荧光特性。     

2,2-二乙氧基乙醇的合成

以40％乙二醛水溶液为原料,经缩醛化、氯代、碱性水解,再经硼氢化钠还原生成2,2-二乙氧基乙醇,总收率36％。其结构经IR,^1H NMR和MS确证。     

Transport Induced by Dichotomic Temperature Fluctuations

The transport process of a Brownian particle in a ratchet-like potential subjected to two exchanging Gaussian white noises is studied. The change of the temperatures is described by a stochastic dichotornic process. By making use of the perturbation method the probability current up to second order in small correlation time τ is obtained, and time-averaged current is evaluated numerically for a whole region of the parameters. For asymptotically fst temperature cycles, the present model yields larger current in comparison with the periodical temperature cycles. Depending on the temperature of cold heat reservoir, the current changes sign as a function of τ.     

乙交酯与2-氢-2-氧-1,3,2-二氧磷杂环己烷的开环共聚研究

聚乙醇酸及其与乳酸的共聚物是一类无毒、有良好的生物相容性和生物可降解材料,它们广泛地用作药物控释体系的载体,牙科植入材料［１,２］．但由于聚乙醇酸的高度可结晶性,使其不溶于包括三氟乙酸在内的几乎所有的有机溶剂,因此通过共聚来改进其物化性质的研究一直方...