新型白桦脂酸糖苷化衍生物的合成及体外抗A549活性

为改善白桦脂酸的水溶性和稳定性,以白桦脂酸苷元为起始原料,对其28-COOH进行甲基化修饰后制得白桦脂酸-28-羧甲酯(1)。分别以D-半乳糖、D-氨基葡萄糖等为起始原料,通过对糖羟基保护与去保护,得到一系列单糖、二糖片段。通过三氯乙酰亚胺酸酯途径合成的糖片段对1的3-位羟基进行修饰,合成了3种白桦脂酸糖苷化衍生物2~4,其结构经¹H NMR、¹³C NMR和MS（ESI）表征。采用MTT法测试了2~4对人肺癌细胞(A549)的体外抑制活性。结果表明：化合物2~4在不同浓度下对A549细胞均有一定抑制作用,其中化合物4在浓度1×10^-3 mmol·L^-1时抑制率最高,达到(91.07±0.18)%。      

热解法制备KY3F10: Yb, RE(RE=Er, Ho, Tm)纳米晶及其特性研究

有机染料和量子点等荧光标记材料存在发射光谱宽、 光热稳定性差和细胞毒性等缺陷, 限制了其在生物学研究中的应用. 镧系掺杂上转换发光材料不存在"自发荧光"和"光漂白"现象, 灵敏度高, 长期稳定性好, 利于活体检测. 论文首次采用热解法, 以油酸和十八烯为表面活性剂和溶剂, 制备了KY₃F₁₀: Yb, RE(RE=Er, Ho, Tm) 纳米晶. 研究了油酸含量对产物形貌和粒径尺寸的影响, 当油酸与十八烯的比例为3:1时, 为制备类球形单分散纳米晶体的最佳工艺条件, 在980 nm半导体激光器激发下, 样品KY₃F₁₀: Yb, RE(RE=Er, Ho, Tm) 分别发射出较强的黄绿、 绿色和蓝色光, 这些结果显示KY₃F₁₀: Yb, RE(RE=Er, Ho, Tm) 纳米粒子作为生物探针在多重荧光标记方面具有优异的特性.     

二连通的二部图的最长圈

本文研究的图 G 为简单的无向的二部图.所用术语和符号除说明外皆同[1].c(G)表示 G 的最长圈的长.以(A_1,A_2)为二分类的二部图记为 G(A_1,A_2).(?)=min{d(v)|v∈V(G)}.已有结果:定理1.设 G(A_1,A_2)为二连通的二部图,则 c(G)≥2min{|A_1|,|A_2|,2δ—2}.定理2.设 G(A_1,A_2)为二连通的二部图,且(?)_i=min{d(v)|v∈A_i}(i=1,     

水杨醛缩精胺及其配合物的合成与生物活性

Ｏ ,Ｏ 二甲基硫代磷酰胺 (简称精胺 )是合成农药甲胺磷的中间体 ,我们以精胺、水杨醛为原料 ,合成了水杨醛缩精胺席夫碱及其铜、镍、锌配合物 (下图 )。生物活性实验表明 ,该席夫碱配体及其配合物具有较好的抑制超氧离子的功效和消灭红蜘蛛的生物活性。1　实验部分1 1　试剂与仪器所用试剂为ＡＲ或ＣＰ ,精胺用前经硅胶柱色谱纯化处理。化合物的Ｃ、Ｈ、Ｎ用Ｐ Ｅ2 4 0自动元素分析仪、铜用碘量法、镍、锌用ＥＤＴＡ法测定。Ｐ Ｅ983富立叶红外光谱仪 ,ＫＢｒ压片法 ;Ｐ Ｅｌａｍｂｄａ 7紫外分光光度计 ,无水甲醇作溶剂。Ｖａｒｉａｎ Ｘ…     

Preparation and Application of a Nanocomposite (MPNS/SMA) in Leather Making

Environmental pollution is one of headache problems in leather tanning industry.Traditionally chrome tanning was the predominant technique used in leather making.However,chrome tanning is being substituted due to its pollution and scarcity of resource.The study of non-chrome tanning in leather shows more interests with the development of nanomaterial and nanotechnology.J.Z.Ma et al.have reported that organic–montmorillonite nanocomposite can raise the shrinkage temperature of pickled pigskin…     

微波场下非贵金属氧化物的升温行为和烹饪油烟的催化净化性能研究

在考察了多种金属氧化物在微波场下升温性能的基础上,制备了用于烹饪油烟催化净化的非贵金属催化剂.实验表明,VB族、V族、B族和B族元素氧化物在微波中升温效果明显,其中Co、Ni和V三种元素氧化物的升温效果最好.涂覆氧化铝的蜂窝堇青石负载V2O5的催化剂具有较稳定的吸波升温性和高油烟催化净化活性.添加La2O3后负载型V2O5催化剂活性明显增加,在微波条件下,含有1%La2O3的负载型V2O5催化剂在150℃可使油烟净化率达到88%以上.     

350例儿童血液中微量元素铁、锌、钙、硒临床分析

临床观察了350例儿童血液微量元素铁、锌、钙、硒缺乏对儿童生长发育的影响。观察结果表明，此350例患儿存在不同程度的微量元素缺乏。其中硒的缺乏最为严重，达91．7％；钙缺乏达85，7％；锌缺乏达25．4％。350例儿童均存在不同程度的生长发育迟缓和多汗、厌食、头发稀少和反复呼吸道感染、贫血、佝偻病等。     

Cu1-xAgxI(x=0.5～0.6)纳米微粒的制备与表征

In the presence of PVPK30,Cu_1-xAg_xI nanoparticles were prepared by ion exchange reaction.The product was characterized by FT-IR,XRD,TEM,EDS and SPS,respectively.It was found that the value of x is ap-proximately 0.5～0.6and the average diameter of the nanoparticles is 10～20nm.The product shows surface photovoltage property of semiconductor and the existence of Cu⁺ greatly enhances the separation efficiency of photoinduced electron-hole pairs.Meanwhile,SPS of Cu_1-xAg_xI nanoparticles with different X (Ag/I)value had been investigated. The results show that when X is 0.5～0.576, the SPS intensity of Cu_1-xAg_xI nanoparticles is highest.     

First oxalate-bridged pentanuclear [Cu(L)]3[Mn(ox)3]2 complexes: synthesis and magnetism

Two novel CuII3MnIII2 pentanuclear oxalato complexes have been synthesized and characterized, namely [Cu(L)]3[Mn(ox)3]2 [L = 1,10-phenanthroline(phen) and 2,2-bipyridyl(bipy)] where ox is the oxalate dianion. Based on i.r., elemental analyses and electronic spectra, thesecomplexesareassignedtoextendedoxalato-bridged structures consisting of two manganese(III) ions and three copper(II) ions, in which each manganese(III) has a distorted octahedral environment and each copper(II) ion a distorted square pyramidal environment. The temperature dependance of the magnetic susceptibility for [Cu(phen)]3[Mn(ox)3]2·4H2O was measured over the 4.2–300K range and the observed data indicates antiferromagnetic spin exchange interaction between the CuII and MnIII ions.     

Oxalate-bridged mixed-valence trinuclear manganese(II)-manganese(III)-manganese(II) complexes: synthesis and magnetism

Summary Two novel Mn^II-Mn^III-Mn^II oxalato complexes have been synthesized and characterized, namely [Mn₂Mn(ox)₃(L)₄](ClO₄) [L = 1,10-phenanthroline (phen) or 5-nitro-1,10-phenanthroline (NO₂-phen), respectively], where ox stands for the oxalate dianion. Based on i.r., elemental analyses and electronic spectra, these complexes are proposed to have extended oxalatobridged structures consisting of Mn^II and Mn^III ions, in which Mn^III and each Mn^II ion has a distorted octahedral environment. The temperature dependence of magnetic susceptibility for [Mn₂Mn(ox)₃(phen)₄] (ClO₄) was measured over the 4.1–300 K range and the observed data were successfully simulated by an equation based on the spin-Hamiltonian operator ( = -2J( _{1 2} + _{2 3})), giving the exchange integral J = -1.57cm^–1. This indicates weak antiferromagnetic spin exchange interaction between Mn^II and Mn^III ions.