环硅氮烷的合成与应用研究进展(1)——环二硅氮烷

环二硅氮烷是有机硅氮化合物中结构与性能比较特殊的一类化合物,在材料化学及配位化学领域有重要的潜在应用前景.综述了近年来环二硅氮烷的合成方法与应用研究进展.在合成方面,主要分为3条路线,分别由环三硅氮烷锂盐、取代硅胺及六氯化二硅为起始物.在应用领域,介绍了环二硅氮烷的离子开环聚合、等离子聚合、与其它单体的共聚、水解和金属配合物的制备及其在陶瓷、粘合剂和预想的催化剂上的应用.     

Modules of the Intermediate Series over Not-finitely Graded Lie Algebras W(Γ)

Let W(Γ)be a class of not-finitely graded Lie algebras related to gener-alized Virasoro algebras with basis{Lα,i,C | α ∈ Γ,i ∈ Z+},which satisfies relations[Lα,i,Lβ,j]=(β-α)Lα+β,i+j+(j-i)Lα+β,i+j+1+δα+β,0δi+j,0α3-α/12C and[C,Lα,i]=0.In this paper,W(Γ)-modules of the intermediate series satisfying some conditions are con-structed and classified.We also obtain modules of the intermediate series over the related Lie superalgebra.     

Averaging on slow and fast cycles of a three time scale system

Pontryagin–Rodygin?s Theorem for slow and fast systems describes the slow drift during the rolling up of the trajectories around the cycles of the fast dynamics. This drift is approximated by the averaging on the cycles. The calculation of this average is generally a difficult task since it requires the knowledge of the closed orbits and their periods. We present two paradigms of three time scale systems where we can overcome this limitation. It is the case of systems the fast dynamics of which have cycles with relaxation presenting or not a canard phenomenon. We can not apply Pontryagin–Rodygin?s Theorem to these systems because their fast equation is itself singularly perturbed. We also investigate the extension of the results to unbounded time intervals. The results are stated classically and proved within the framework of nonstandard analysis.     

Enantioseparation of citalopram analogues with sulfated β‐cyclodextrin by capillary electrophoresis

Capillary electrophoresis methods were developed for the enantiomeric separation of 27 citalopram analogues. Sulfated β‐cyclodextrin was the most broadly selective and useful chiral selector. The separations of most of the citalopram analogue compounds reported in this work have not been reported previously. Excellent enantiomeric separations were obtained for 26 out of 27 compounds, and most of the separations were achieved within 10 min. The effects of chemical parameters such as chiral selector types, buffer types, chiral selector and buffer concentrations, buffer pH and organic modifiers on the separation were investigated. The influence of analyte structure on separation also was examined and discussed.     

Evaluating the biochemical changes of LPS-stimulated endothelial cells by synchrotron FTIR microspectroscopy at a single-cell level

Analytical and Bioanalytical Chemistry - Endothelial damage is a major manifestation in many forms of heart and lung injuries induced by lipopolysaccharide (LPS), but the biochemical responses and...     

Label-free, non-derivatization CRET detection platform for 6-mercaptopurine based on the distance-dependent optical properties of gold nanoparticles

A label-free, non-derivatization chemiluminescence resonance energy transfer (CRET) detection platform has been developed for the detection of the non-fluorescent small molecule 6-mercaptopurine. This CRET process arose from a chemiluminescent (CL) donor-acceptor system in which the reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H(2)O(2)-fluorescein (maximum emission at 521.6 nm) served as the donor and gold nanoparticles (AuNPs, maximum absorption at 520.0 nm) served as the acceptor. This process caused a significant decrease in the CL signal of the TCPO-H(2)O(2)-fluorescein reaction. The presence of 6-mercaptopurine induced an aggregation of AuNPs with the assistance of Cu(2+) ions through cooperative metal-ligand interactions that was accompanied by a distinct change in color and optical properties. The maximum absorption band of the AuNPs was red-shifted to 721.0 nm and no longer overlapped with the CL spectrum of the reaction; as a result, the CL signal was restored. This CRET system exhibited a wide linear range, from 9.0 nmol L(-1) to 18.0 μmol L(-1), and a low detection limit (0.62 nmol L(-1)) for 6-mercaptopurine. The applicability of the proposed CRET system was evaluated by analysis of 6-mercaptopurine in spiked human plasma samples.     

Label‐Free,Non‐Derivatization CRET Detection Platform for 6‐Mercaptopurine Based on the Distance‐Dependent Optical Properties of Gold Nanoparticles

A label‐free, non‐derivatization chemiluminescence resonance energy transfer (CRET) detection platform has been developed for the detection of the non‐fluorescent small molecule 6‐mercaptopurine. This CRET process arose from a chemiluminescent (CL) donor–acceptor system in which the reaction of bis(2,4,6‐trichlorophenyl)oxalate (TCPO)–H₂O₂–fluorescein (maximum emission at 521.6 nm) served as the donor and gold nanoparticles (AuNPs, maximum absorption at 520.0 nm) served as the acceptor. This process caused a significant decrease in the CL signal of the TCPO–H₂O₂–fluorescein reaction. The presence of 6‐mercaptopurine induced an aggregation of AuNPs with the assistance of Cu²⁺ ions through cooperative metal–ligand interactions that was accompanied by a distinct change in color and optical properties. The maximum absorption band of the AuNPs was red‐shifted to 721.0 nm and no longer overlapped with the CL spectrum of the reaction; as a result, the CL signal was restored. This CRET system exhibited a wide linear range, from 9.0 nmol L^?1 to 18.0 μmol L^?1, and a low detection limit (0.62 nmol L^?1) for 6‐mercaptopurine. The applicability of the proposed CRET system was evaluated by analysis of 6‐mercaptopurine in spiked human plasma samples.     

基于特征分解的红外焦平面非均匀性校正算法

针对目前红外焦平面自适应场景校正算法工程应用的局限,提出了一种基于红外焦平面非均匀性特征分解的场景校正算法。分析了红外焦平面非性匀性构成因素,把其中的高频部分分解成盲点、斑块、行列非均匀性等,把缓慢变化的低频部分分解成梯度渐变非均匀性;分别对各类非均匀性采用不同的校正算法;合并校正结果,得到校正后的图像。实验结果表明,该算法校正精度高、收敛速度快、抑止目标退化能力强,适合工程应用。     

环己基(三甲基硅基亚甲基)锡二芳香酸酯的合成、结构和抗癌活性

采用环己基(三甲基硅基亚甲基)二氯化锡和芳香酸(物质的量比1:2)在三乙胺存在下,合成了8种新的混合二烃基锡化合物环己基(三甲基硅基亚甲基)锡二芳香酸酯。 通过IR、¹H NMR、¹³C NMR和元素分析等技术手段对它们的结构进行了表征;部分化合物的生物活性测定初步结果表明,它们对肺腺癌细胞(A549)有较好的体外抗癌活性,抑制率均在75%以上。