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Y F Zhao

Publications and source records attributed to Y F Zhao.

42 records · Page 3Linked to original sources
PubMed1985

X-ray photoelectron spectra study on the derivatives of N-beta-phenethyl amine and N-beta-phenethyl glycine.

The X-ray photoelectron spectra of sixteen derivatives of N-beta-phenethyl amine and N-beta-phenethyl glycine have been studied. The effect of different structures on N1s binding energy and that of their Pauling's atomic charge density on the nitrogen atoms are investigated. The experimental binding energy of N1s is proportional to the calculated Pauling's atomic charge density. It shows that the phosphoryl group is the strongest nitrogen lone pair electron localizing group as compared with the corresponding sulfonyl and acyl derivatives. The XPS results agree with the data that there is no decarbonylation during the synthesis of N-dialkylphosphoryl-tetrahydro-3-benzazepin-1-one. In addition, since the N1s in P-N bond is smaller than that in S-N and C-N bonds, the phosphoryl group can be removed under much milder conditions. These results provide a semi-empirical evidence for the synthesis of the skeleton of the cephalotaxine. It also differentiates the reaction paths for these three different amino protecting groups.

Alkaloids↗
PubMedDate not supplied

Experimental study of bone growth around a dental implant after Surgibone grafting.

Histologic and histomorphometric results of bone growth around titanium alloy screw-type implants after Surgibone grafting in New Zealand white rabbits are presented. At 21 days, new bone was formed along the surface of the implant. At 84 days, newly formed bone replaced almost all of the trabecular bone of the graft and reached the shoulder level of the implant. There was a higher percentage of host bone area at 84 days than at any of the earlier experimental periods (P < .01). The average mineral apposition rates ranged from 1.82 to 2.35 microns/day in original bone and 2.55 to 2.80 microns/day in newly formed bone. The results suggest that Surgibone grafting in combination with dental implants can be used to increase the height of the recipient bone and therefore aid in the fixation of the implant in this animal model.

Animals↗