简介:本文由色胺或5-甲氧基色胺与相应的酰氯在三乙胺的催化下缩合合成了六个双色胺Nb,Nb′二酰胺化合物,其中四个为新化合物。经过放射配体结合竞争抑制性试验证明,该六个化合物均与安定受体有较好的亲和力。
简介:K2NbOF5·H2OandK2TaF7werepreparedthroughmeltingNb2O5andTa2O5respectivelywithFHF2·2H2O,followedbyrecrystallizing.ThehydrolysispropertiesofK2NbOF5andK2TaF7weredeterminedagainbyusingarapidlyquenchvessel.Astemperature(from250to550℃)andpressure(from500to1500bars)increase,thedegreeofhydrolysisofbothK2NbOF5andK2TaF7willincrease.Nb-andTa-fluorinecomplexcompoundsareinstableinsupercriticalaqueousfluids.ThedegreeofhydrolysisofbothK2NbOF5andK2TaF7decreaseswithincreasingconcentra-tionofHF,independentoftheconcentrationofNaF.ThepartitioncoefficientsofNbandTabetweengraniticmeltandfluidphasearelessthan0.15,ie.,mostofNbandTaareleftingraniticmelt.ThepartitioncoefficientofTaismoredependentontheconcentrationofHFthanthatofNb.ThesignificanceofhydrolysisinNb-ansTamineralizationisalsodiscussedinthepresentpaper.
简介:AbstractVitiligo, a common skin depigmentation disorder, is the result of complex interactions of genetic, immunological, environmental, and biochemical events. Treatments for vitiligo include drugs, phototherapy, surgical transplantation, and so on. Among them, the efficacy of narrow band-ultraviolet B has been confirmed. By inducing keratinocyte-derived factors and signalings, narrow band-ultraviolet B can trigger and/or promote the mobilization of melanocytes which migrate to lesional epidermis ultimately, leads to the repigmentation of white patches. The mobilization of melanocytes includes stages of activation, migration, proliferation, and differentiation. Elucidating processes that enable the specific mobilization of melanocytes and the signaling pathways and factors involved, will help the development of new drugs and methods for the treatment of vitiligo.