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A mild method for the synthesis of carbamates from amino alcohols involves sequential carboxylation with carbon dioxide, followed by a Mitsunobu reaction. Unexpectedly, the stereochemical course of the Mitsunobu reaction is dependent on whether the carbamic acid intermediate is N-substituted with hydrogen (retention) or carbon (inversion). 相似文献
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Gareth AD Hardy Nesrina Imami Mark R Nelson Ann K Sullivan Ron Moss Marlén MI Aasa-Chapman Brian Gazzard Frances M Gotch 《Journal of immune based therapies and vaccines》2007,5(1):6-12
Background
Fully functional HIV-1-specific CD8 and CD4 effector T-cell responses are vital to the containment of viral activity and disease progression. These responses are lacking in HIV-1-infected patients with progressive disease. We attempted to augment fully functional HIV-1-specific CD8 and CD4 effector T-cell responses in patients with advanced chronic HIV-1 infection. 相似文献3.
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Lin Y Böker A Skaff H Cookson D Dinsmore AD Emrick T Russell TP 《Langmuir : the ACS journal of surfaces and colloids》2005,21(1):191-194
The self-assembly of nanoparticles at fluid interfaces, driven by the reduction in interfacial energy, was investigated. With spherical, tri-n-octyl-phosphine-oxide covered cadmium selenide (CdSe) nanoparticles (1-8 nm), thermal fluctuations compete with the interfacial segregation giving rise to a size-dependent self-assembly of the particles. The structure of the nanoparticle assembly was studied using electron microscopy, atomic force microscopy, and X-ray scattering in situ, which indicate that the particles form a densely packed monolayer. The energetics of the adsorption of nanoparticles onto the interface was revealed by time-dependent fluorescence studies on a mixture of two different sized nanoparticles at the interface. The dynamics of the nanoparticles at the fluid interface, probed using fluorescence photobleaching methods, suggests a liquid-like behavior. The results have implications in the design of hierarchical self-assemblies of nanoparticles for the one-step fabrication of devices on multiple length scales. 相似文献
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Self-assembled shells composed of colloidal particles: fabrication and characterization 总被引:1,自引:0,他引:1
Hsu MF Nikolaides MG Dinsmore AD Bausch AR Gordon VD Chen X Hutchinson JW Weitz DA Marquez M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(7):2963-2970
We construct shells with tunable morphology and mechanical response with colloidal particles that self-assemble at the interface of emulsion droplets. Particles self-assemble to minimize the total interfacial energy, spontaneously forming a particle layer that encapsulates the droplets. We stabilize these layers to form solid shells at the droplet interface by aggregating the particles, connecting the particles with adsorbed polymer, or fusing the particles. These techniques reproducibly yield shells with controllable properties such as elastic moduli and breaking forces. To enable diffusive exchange through the particle shells, we transfer them into solvents that are miscible with the encapsulant. We characterize the mechanical properties of the shells by measuring the response to deformation by calibrated microcantilevers. 相似文献
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Mallick K Witcomb MJ Dinsmore A Scurrell MS 《Langmuir : the ACS journal of surfaces and colloids》2005,21(17):7964-7967
This work demonstrated a facile route for the synthesis of poly(3,5-dimethyl aniline) nanofibers by polymerization of 3,5-dimethyl aniline using Pd-acetate as the oxidant. The reduction of Pd ion is accompanied by oxidative polymerization of 3,5-dimethyl aniline, leading to a metal-polymer composite material. Palladium nanoparticles (approximately 2 nm) are uniformly distributed throughout the polymer that makes the composite material a unique morphology. The resultant composite material was characterized by means of different techniques. IR and Raman spectra provide the information on the chemical structure of the polymer. TEM images show the morphology of the polymer and size of the metal particles. 相似文献
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Kaushik Mallick Mike J. Witcomb Andy Dinsmore Mike S. Scurrell 《Macromolecular rapid communications》2005,26(4):232-235
Summary: We report a new method for the preparation of polyaniline nanoballs by using HAuCl4 as an oxidizing agent. During the reaction, aniline is oxidized and forms polyaniline whilst the hydrogen tetrachloroaurate is reduced and forms gold nanoparticles. These gold nanoparticles are found to decorate the nanoballs.
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