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排序方式: 共有294条查询结果,搜索用时 312 毫秒
291.
Braga D d'Agostino S D'Amen E Grepioni F 《Chemical communications (Cambridge, England)》2011,47(18):5154-5156
A new silver(I) complex with 1-phenyl-3-(quinolin-5-yl)urea has been prepared, acting as a supramolecular supergelator in the presence of polar solvents. In open vials temperature dependent, reversible gel-to-xerogel transition is observed, while in sealed vials direct crystallization of four polymorphs of the same gelling compound is achieved, depending on the gelling solvent. 相似文献
292.
S. Sapino M. E. Carlotti R. Cavalli E. Ugazio G. Berlier L. Gastaldi S. Morel 《Journal of inclusion phenomena and macrocyclic chemistry》2013,75(1-2):69-76
Gamma-oryzanol (GO), a mixture of ferulic acid esters, has recently attracted a great interest as natural antioxidant extracted from rice-bran oil, usually employed to stabilize food and pharmaceutical raw materials, moreover as sunscreen in cosmetic formulations. Its usefulness, however, is limited by its fast degradation. A recently proposed approach to increase the stability and effectiveness of antioxidants is based on the inclusion in supramolecular structures (nanoparticles, cyclodextrins, liposomes, etc.). In this work we studied the inclusion of GO in β-cyclodextrin-based nanosponges which in the last few years have been chosen for their ability to encapsulate a great variety of substances to decrease their side-effects and to protect them from degradation. The inclusion complex was prepared in 1:1 w/w ratio and characterized by DSC, XRPD and membrane diffusion runs. The photodegradation of GO upon either UVA or UVB irradiation was found to be slowed down by inclusion in nanosponges. The antioxidant effectiveness of the inclusion complex was also assessed and in vitro experiments on porcine ear skin revealed a certain accumulation of GO also when entrapped in the host structure. 相似文献
293.
M. E. Carlotti S. Sapino M. Gallarate M. Trotta R. Cavalli E. Ugazio 《Journal of Dispersion Science and Technology》2013,34(10):1460-1470
The aim of this work was to prepare and to characterize stable O/W emulsions containing liquid crystals as vehicles of mandelic acid. Influence of some components on the behavior of the systems has been also studied. Particularly, the release of mandelic acid was compared from different formulations showing that the lamellar phases prolonged the active release and consequently they might reduce its irritation potential on the skin. Results of evaporation test suggested that lamellar phases contributed to increase the moisturizing action of these emulsions by limiting their water loss. 相似文献
294.
E. Cavalli 《Journal of Physics and Chemistry of Solids》2008,69(1):29-34
Single crystals of MWO4 (M=Mg, Zn, Cd) and MgMoO4 doped with Cr3+ have been grown by the flux growth method. Their optical spectra have been systematically measured and assigned on the basis of the classical Ligand Field Theory. The exchange charge model of the crystal field has then been applied to calculate the crystal field parameters (CFPs) and the energy levels of the Cr3+ ion in all studied crystals. These are in reasonable agreement with the experimental data. Systematic trends in the CFPs values, crystal field splittings and Racah parameters have been evidenced and their relation with sizes and symmetry properties of the host cavities occupied by Cr3+ has been pointed out. 相似文献