Microphase separation behavior on the surfaces of PEG-MDI-PDMS multiblock copolymer coatings

A series of poly(ethylene glycol)(PEG)-4,4′-diphenylmethanediisocyanate(MDI)-poly(dimethylsiloxane) (PDMS) multiblock copolymers were synthesized by employing two-step growth polymerization technique. Atomic force microscopy (AFM) observed nanoscopically well-organized phase-separated surfaces consisting of hydrophilic domain from PEG and MDI segments and hydrophobic domain from PDMS segments even with 50 wt.% PDMS in the copolymer, and the multiblock copolymer coatings presented a surface free energy of as low as 6-8 mN m⁻¹.     

三明治结构rGO/Fe3O4@mSiO2载体的构筑及协同抗肿瘤性能

采用温和的反应条件,制备出三明治结构rGO/Fe_3O_4@mSiO_2,利用SEM、TEM、FTIR、XRD和N_2吸附-脱附等对其形貌和性能进行表征,考查了其对Hela细胞的毒性和细胞荧光成像效果,并探讨了其形成机理。实验结果表明:rGO/Fe_3O_4@mSiO_2具有较高的比表面积(217 m~2·g~(-1)),对抗癌药物五氟尿嘧啶(5-FU)的载药率达到57.34%;它还具有较好的磁性,磁饱和强度为32 emu·g-1;而且rGO/Fe_3O_4@mSiO_2纳米复合物在光照条件下具有优异的光热转换性能,对He La细胞表现出明显的杀伤效果。     

House bulb light-induced photochemical acetalization of carbonyl compounds catalyzed by Eosin Y

We have systematically studied the reactions of acetalization and found that high reaction efficiency can be achieved using cheap and readily available organic Eosin Y as catalyst. The reaction proceeds smoothly under house bulbs and shows excellent functional group tolerance. The substrates of the reaction system are compatible with aromatic aldehydes, aliphatic aldehydes, aromatic ketones, and cyclic ketones with high yields.     

Hydrogen-bonded networks of 2,2′-substituted 4,4′-biimidazoles: New ligands for the assembled metal complexes

4,4′-Biimidazole derivatives having alkyl-substituents at 2- and 2′-positions were synthesized as new component molecules of supramolecular assemblies based on hydrogen-bonding interaction. The crystal structure analyses of methyl and ethyl derivatives revealed intriguing three-dimensional structures constructed by hydrogen-bonded networks. Furthermore, the methyl derivative formed a six-membered cyclic motif of hydrogen-bonded network to build up a channel structure. The ethyl derivative gave the two polymorphous, anhydrate and dihydrate, depending on conditions of the crystallization. The anhydrate constructed three-dimensional hydrogen-bonded networks by direct N–H⋯N hydrogen-bondings. In the crystal structure of the dihydrate of ethyl derivative, three-dimensional hydrogen-bonding interaction through water molecules formed a channel structure.     

A novel chemosensor for Fe3+ based on open–closed-loop mechanism and imaging in living cells

Research on Chemical Intermediates - In this paper, a novel chemosensor (named L1) for Fe3+ based on the rhodamine 6G and o-vanillin has been synthesized, which can selectively recognize Fe3+. The...     

基于Mathematica软件下等效电子光谱项的推求

基于Mathematica计算软件,借助组合数学方法,编写了推求任意等效电子组态光谱项的计算程序,系统地给出了fn(n=1～14)及gn(n=1～18)组态的光谱项.     

A strategy for the enrichment and characterization of disulfide bond-contained proteins from Chinese cobra (Naja atra) venom

A new strategy combined gold-coated magnetic nanocomposites assisted enrichment with mass spectrometry was developed for the characterization of disulfide bond-contained proteins from Chinese cobra (Naja atra) venom. In this work, core-shell nanocomposites were synthesized by the seed-mediated growth method and used for the enrichment of snake venom proteins containing disulfide bonds. A total of 3545 tryptic digested peptides derived from 96 venom proteins in Naja atra venom were identified. The venom proteins comprised 14 toxin families including three-finger toxins, phospholipase A₂, snake venom metalloproteinase, cobra venom factor, and so forth. Extra 16 venom proteins were detected exclusively in the nanocomposites set, among which 11 venom proteins were from the three-finger toxins family. In the present study, the proposed simple and efficient protocol replaced the tedious and laborious technologies commonly used for pre-separating crude snake venom, suggesting widely implementation in low-abundance or trace disulfide bond-contained proteins or peptides characterization.     

ASYMPTOTIC STABILITY OF A SINGULAR SYSTEM WITH DISTRIBUTED DELAYS

Based on the stability theory of functional differential equations, this paper studies the asymptotic stability of a singular system with distributed delays by constructing suitable Lyapunov functionals and applying the linear matrix inequalities. A numerical example is given to show the effectiveness of the main results.     

绕积马氏链的状态

主要研究了绕积马氏链的各种状态,得到了相应的一些充要条件．同时利用Foguel的L1-理论对单链X常返性与瞬时性进行了讨论,回答了单链X是π-不可约链的本质,即绕积马氏链的相空间是最小闭集．     

序数权重统一表示下的权重稳健性Hasse图分析

认识多种序数赋权方法的共性,有助于摆脱方法选择困扰,增强其实用效果。首先以线性函数为目标函数,以权重关系构造约束条件,建立线性规划。在此基础上证明了任意权重均可由线性规划的极值点集来表示,揭示了序数权重实质上是极值点的加权线性组合。进一步针对赋权方法稳健性不足的问题,利用极值点构建偏序关系,通过Hasse图增强权重排序的稳健性。实例分析表明,尽管序数权重不同,但与偏序方法相结合,均能得到类似的分析结果。