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To analyze and find factors affecting the height of adjacent gingival papilla of maxillary central incisor single implant in human in order to promote the esthetic result of dental implants.Sixteen maxillary central incisor single implants of 16 patients and 30 sites of adjacent tissues and prosthesis were evaluated. Data on the height of adjacent gingival papilla of dental implant and relative factors were obtained from clinical parameters, photographs, research models, and X radiographs.The mean and standard deviation of adjacent gingival papilla height of maxillary central incisor single implant were (4.01 +/- 1.85) mm. Statistical analysis revealed that factors affecting the height of adjacent gingival papilla of implant were as following from strong to weak: vertical distance between contact point and gingival margin, vertical distance between proximal bone level of natural tooth and implant abutment, vertical distance between proximal bone level of natural tooth and contact point, proximal protruding degree of crown, horizontal distance between abutment and root, length ratio of the crown and fixture, vertical distance between proximal bone level of implant and abutment, lip-side protruding degree of crown, probing depth.Multiple factors affected the height of adjacent gingival papilla of maxillary central incisor single implant in human.

To evaluate clinical results of implant-supported complete denture of 12 patients with severe chronic periodontitis.After systematically periodontic treatment and controlling the inflammation, 12 cases with severe chronic periodontitis were extracted the residual teeth and received immediate implant placement. The implant-supported complete dentures were finished at 5 or 6 months after operation. Restorative results were evaluated with clinical examination, radiological examination and chief complaints of the patients.A total of 108 implants were placed into 20 dental arches, including 37 immediate implants. Average loading was for 3 years and all implants were stable. Progressive bone resorption was observed around two implants. The average bone resorption of other peri-implants was (1.33 +/- 0.10) mm. The implant survival rate was 98.1%. The immediate implant survival rate was 97.3%.After periodontic treatment, the patients with severe chronic periodontitis could be restored using immediate implant placement and implant-supported complete denture. It can shorten the treatment period, reduce absorption of alveolar and obtain a favorable result by oral health care.

To study the effect of icariin on vascular endothelial cells (VECs) injury induced by hypoxia.The hypoxia-ischemia model was established. The effect of icariin on injury of VECs activity induced by hypoxia was determined by MTT assay. The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and lactate dehydrogenase (LDH) activity in cell homogenate were measured with corresponding kit. Effect of icariin on cells apoptosis induced by hypoxia was determined by Hoechst 33342 fluorescent staining, cell ultrastructure observation under transmission electron microscopy and analysis on gene fragmentation by flow cytometry and DNA gel electrophoresis.ICA could inhibit the hypoxia induced VECs reduction, suppress LDH activity, reduce the MDA production, and enhance SOD activity under hypoxia. Hypoxia could induce VECs apoptosis, revealed chromation condensed in nuclei with the fragments arranged along the nuclear membrane. DNA gel electrophoresis showed typical ladder strands of DNA. Cells displayed a typical sub-diploid peak in flow cytometry. ICA could significantly inhibit the hypoxia induced apoptosis of VECs.ICA has the protective effect on hypoxia injured VECs, which may be related to its effect of anti-apoptosis, anti-lipid peroxidation and SOD activity enhancing.

The coupling between ligand binding and protein conformational change is the heart of biological network. “Lock and key” theory and “induced fit” theory were early contributions to our understanding for explaining how an enzyme binds to a substrate. It was accepted that the binding of a substrate to an enzyme is often accompanied by conformational changes of the enzyme. However, whether the substrate-induced complementary conformation is flexible or rigid after a catalytic reaction remains to be determined. By testing the enzyme activity and intrinsic fluorescence of a substrate non-specific Eisenia fetida protease-I with different substrates, we show that when this enzyme reacts with a first substrate, it utilises the “induced fit” mechanism. However, in its reaction with further substrates, either the “lock and key” or “induced fit” mechanisms will be used depending on the degree of conformational change required. In contrast to the high activity of the native protease, the chromozym-Th (or -Ch)-induced protease was unable to react with chromozym-U. Chromozym-U-induced enzyme, however, had high activity with chromozym-Th and chromozym-Ch. When low concentrations of GuHCl were used to disturb the conformation of the enzyme, only small changes in intrinsic fluorescence of the CTH-induced protease were detected, in contrast to the native enzyme whose intrinsic fluorescence markedly increased. This indicates a relatively high rigidity of the substrate-induced enzyme compared with the native protease. It also indicates that the “induced fit” theory is not an adequate explanation of the mechanisms involved in such reactions. Utilising a “lock and key” mechanism for such secondary reactions may have adaptive value in that it facilitates high efficiency in enzymatic reactions.

Nitrogen heterocycles could be prepared in good yields via intramolecular cyclization of tertiary amines and alkenes promoted by KOt-Bu-DMF.

An organocatalytic three-component reaction of isatins, malononitrile and isocyanoacetates provided 3,3'-dihydropyrryl-spirooxindoles in excellent yields and enantioselectivities. The products could be readily converted to valuable 3,3'-pyrrolidinyl-spirooxindoles.