ABSTRACT
Objective Establish an experimental model for primary subchondral bone osteoblasts culture of neonatal SD rat's condylar process. Methods Under the condition of sterile,24-hour SD rat was executed and its condylar process was isolated. Removing cartilage layer, the subchondral bone was exposed obviously, then it was cultured with modified repeating enzymatic digestion-adherent explants method. The cellular morphology was identified with invert microscope and immunohistochemistry staining, the osteoblasts were identified by alkaline phosphorase (ALP) staining and calcified nodules staining, and the proliferation of the acquired cells was examined by methyl thiazolyl tetrazolium (MTT) assay. Results A variety of cell morphologies were observed, such as spindle-shaped, triangular and irregular-shape, and their cell processes were significant. The alkaline phosphatase staining and calcified nodules staining of cultured osteoblasts with mineralized nodules were positive. Cells grew slowly in 1-3 days, and the cells growth reached the highest level at the 8th day. The cells growth trend has gradually slowed down after 8 days. Conclusion The method is an efficient way to culture and obtain purified neonatal SD rat's subchondral bone osteoblasts with typical characteristics.
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Recently,the traditional English teaching model can not match the social demand to the medical postgraduate students.This paper analyses the effective factor of English teaching and learning.We hope to explore a new set of capability cultivation basal English teaching model of medical postgraduate students through editing teaching outline,evaluating demand,implementing classified teaching,giving medical electives and improving examination means.
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Objective: To study the corrosion resistance of the ortho do ntic magnets with titanium nitride (TiN) coating. Methods: The m agnets coated TiN film were immersed into artificial saliva at 37 ℃ for two mon ths. During the immersion, the concentration of iron ion in the artificial saliv a was analyzed with atomic absorption spectrophotometry(AAS). After immersion, t he weight change of the magnets was measured.The magnets coated with nickel film and without coating were used as the controls.Results: In all t he groups, iron ion concentration in the artificial saliva increased with the in crease of immersion time(P
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Objective: To study the corrosion resistance of orthodontic magnet with titanium nitride coating in artificial saliva. Methods: 6 samples of magnet in the size 3 mm?5 mm?7 mm were prepared.3 of them were coated with titanium nitride by plasma enhanced chemical vapor deposition,another 3 without coating were used as controls.The samples were immersed into artificial saliva at 37 ℃ for one month. Then the surface characters of two kinds of magnets were observed with the naked eye and by electron-probe microanalysis (EPMA). Results: The surface of the magnets with titanium nitride coating was fine and close in texture and there were no cleft and disintegrated area. However, that of the magnets without titanium nitride coating was uneven and coarse in texture,and there were evident clefts and disintegrated areas. Conclusion: The corrosion resistance of orthodontic magnets with titanium nitride coating is stronger than that without coating.
ABSTRACT
The Compound Bioceramic (CBC),a newly developed artificial bone material,were im- planted in the man-made defects on madibular bodies of four dogs.The an imals were sacri- ficed three months later.The specimens were prepared by routine procedures.The interfaces between the CBC materials and bones were studied by electromicroscope scanning and X-ray energy spectrum analysis:the results showed that the CBC materials could be bioconnected with bones (osseous bond as was called).The study suggested that the osseous bond mecha- nism of the CBC material be related to the ion migration and deposition of calcium and phosphate on the interfaces.