生地当归药队煎剂的表面增强拉曼散射光谱

为揭示单味煎剂与方剂间的关系,分别测试分析了生地当归药队、单味药生地和单味药当归煎剂的表面增强拉曼散射(surface-enhanced Raman scattering, SERS)光谱,并对其进行谱峰归属。本文主要针对存在于三种煎剂中的17个拉曼信号(538,622,732,761,835,876,959,1 145,1 245,1 276,1 326,1 402, 1 456,1 470,1 518,1 546和1 605 cm-1)进行讨论。生地当归药队煎剂SERS光谱在538,732,761,835,876,959,1 145,1 245,1 276,1 326,1 402,1 456,1 470,1 518和1 605 cm-1处,出现15个明显的拉曼信号;生地煎剂SERS光谱在538,761,835,876,959,1 145,1 245,1 276,1 326,1 402,1 470,1 518和1 546 cm-1处,出现13个明显的拉曼信号;当归煎剂SERS光谱在538,622,732,761,835,876,959,1 245,1 326和1 402 cm-1处,出现10个明显的拉曼信号。生地当归药队煎剂SERS光谱保留了和未观察到生地和当归单味煎剂的某些拉曼峰,且产生了生地和当归单味煎剂中所没有的拉曼信号(1 456和1 605 cm-1),即产生新药物成分。生地当归药队煎剂所包含的药物成分并非是生地和当归单味药物煎剂所含药物成分的简单相加。结果表明,SERS光谱可能为方剂研究提供一种高灵敏度、快速准确和操作简单的检测方法。     

Generation of Hierarchical Topologies from Photocrosslinkable,Particle‐Stabilized Emulsions

Summary: We describe a way to obtain biomimetic, hierarchical surface morphologies. In order to mimic natural surfaces more accurately such as lotus leaves and gecko feet, we employ a strategy that bears many of the attractive characteristics of natural materials synthesis. The system in question consists of a photocurable monomer and water. To this quasi‐two‐component system we add polymer latex spheres. The monomer–water interface is then manipulated according to the well‐established science of complex fluids. Drawing from the rich phase behavior of particle‐stabilized emulsions, we demonstrate the creation of complex biomimetic morphologies over many length scales. The resulting structures are then solidified by crosslinking the monomer with UV light.

Comparison of an AFM image of a PMMA colloidosome assembly with that of the textured surface of a superhydrophobic Hygoryza aristata leaf (inset).     

Fabrication of Robust High‐Quality ORMOCER® Inverse Opals

Summary: The nanostructuring of ORMOCER® to form inverse opals is described. For this purpose a polymer opal is used as a template and infiltrated with liquid ORMOCER®. After photopolymerization of the resin the host opal is dissolved in tetrahydrofuran and an ORMOCER® inverse opal is obtained. It shows excellent periodicity (by SEM) and optical properties to reveal a high degree of face centered cubic order. This replication process leads to a nanostructured photonic crystal with the outstanding mechanical properties of ORMOCER® and high temperature stability up to 350 °C.

ORMOCER® inverse opal annealed at 200 °C for 10 h.     

Synthesis and characterization of synthetic polymer colloids colloidally stabilized by cationized starch oligomers

A method is developed for anchoring enzymatically degraded cationized starch as electrosteric stabilizers onto synthetic latices, using cerium(IV) to create free‐radical grafting sites on the starch. Direct anchoring of debranched starch onto a poly(methyl methacrylate) seed latex yields a latex stabilized by well‐defined oligosaccharides. Using α‐amylase to randomly cleave starch to form (1→4)‐α‐glucans, and a comonomer, N‐isopropyl acrylamide (NIPAM), whose corresponding polymer exhibits a lower critical solution temperature (LCST), creates a means to synthesize block (or graft) oligomers of oligosaccharide and synthetic polymer, which are water soluble at room temperature. Above 30 °C, they become amphiphilic and form self‐emulsifying nanoparticles (sometimes termed “frozen micelles”) from which a synthetic latex is grown after addition of methyl methacrylate, the collapsed NIPAM‐containing entities functioning as a type of in situ seed. This synthesis of stable synthetic latex particles is shown to have a high grafting efficiency. The starch fragments were characterized by ¹H solution‐state NMR before grafting, and ¹³C solid‐state cross‐polarization magic‐angle spinning (CP‐MAS) NMR was used to characterize the starch oligomers actually grafted on the final latex. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1836–1852, 2009     

Tuning intermicellar potential of Triton X-100-anthranilic acid mixed micelles

Structural parameters of micelles formed by Triton X-100 in the presence of solubilized anthranilic acid at different pH values was investigated using light scattering and small angle neutron scattering. Analysis of the SANS data indicate that micelles are oblate ellipsoidal in nature with little variation in the dimensions, in the investigated pH range (from 0.5 to 6.0). The interaction potential of the micelles shows a minimum closer to the isoelectric point of anthranilic acid. A similar variation is observed in the cloud point of the micelles with pH. The observed variation in the interaction potential with pH of the micellar solution can be explained in terms of the reversal of charge on anthranilic acid due to shift in the acid-base equilibrium. The variation in interaction potential and cloud point with pH is modelled using Coulombic repulsion of charged molecules at the micelle interface.      

Surface modification of epoxy‐functionalized acrylate colloids

A synthetic route towards surface modified, monodisperse, spherical particles is presented. The precursor particles exhibit epoxy‐functionalities which can be opened afterwards with an appropriate nucleophile. Via this route, dye labeled particles are obtained. Copyright © 2004 John Wiley & Sons, Ltd.