The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 

A spectroscopic study of calcium surface sites and adsorbed iron species at aqueous fluorapatite by means of (1)h and (31)p MAS NMR.

Assignments of the protolytic speciation at the calcium hydroxyl surface sites of synthetic fluorapatite and the chemical interactions between fluorapatite-maghemite and fluorapatite-Fe2+ ions have been studied by means of 1H and 31P single-pulse and 31P CP MAS NMR. Three possible forms of calcium hydroxyl surface sites have been suggested and assigned to identical with CaOH, identical with Ca(OH)2-, and identical with CaOH2+, and their mutual ratios were found to vary as a function of pH. Due to their paramagnetic properties, iron species and Fe2+ ions adsorbed at the fluorapatite surface display a broad spinning sideband manifold in the single-pulse 31P MAS NMR spectra. The resonance lines in the 31P CP MAS NMR spectra originating from the bulk phosphate groups PO43- and phosphorus surface sites identical with POx and identical with POxH decrease with increasing Fe2+ ion adsorption. When iron species originating from maghemite are adsorbed at the fluorapatite surface, no 31P NMR signal is detected, which supports the hypothesis that surface reactions occur between the phosphorus surface sites of fluorapatite and iron species.[1]

References

  1. A spectroscopic study of calcium surface sites and adsorbed iron species at aqueous fluorapatite by means of (1)h and (31)p MAS NMR. Sandstr??m, D.E., Jarlbring, M., Antzutkin, O.N., Forsling, W. Langmuir : the ACS journal of surfaces and colloids (2006) [Pubmed]
 
WikiGenes - Universities