Objective: To measure the convergence angles of teeth in different teeth positions and different denture designs.Methods:Mesio-distal widths and labio-lingual widths were measured on 226 teeth according to three points in a line on three surfaces (gingival, middle and incise) of each tooth.The distance between every point and the counterpart point in the adjacent surface was measured.Then convergence angles were calculated. Results:The means of the angles were 4.13°±0.77°,4.14°±0.76°, 4.46°±0.95°, 4.76°±0.84° on the first and second premolar, the first and second molar,respectively . There were significant differences between the premolars and molars(P<0.05).On the dentures with the designs of monocrown, triunit-bridge and long bridge the means of the angles were 3.78°±0.74°,4.69°±0.75° and 5.08°±0.85° respectively,the angle on the denture with the design of monocrown was smaller than that of bridge (P<0.05).Conclusion:The convergence angles are different according to different teeth positions and different denture designs, so they should be adjusted according to the clinical requirements.

0.01). There was a significant difference in TIMP-1,-2 expressions between saccule injury group and control group (P

s〕 Objective:To investigate the influence of repeated firings on the color of porcelain fused to metal crown(PFM) . Methods: 5 PFM samples were prepared and fired for 9 times.The color of the samples was measured following firing with CIE1976 L*a*b* color system . The color difference ?E ab *,hue angle h ab * and chroma C ab * were calculated according to the following calculations:?E ab * ={(?L*) 2 +(?a*) 2 +(?b*) 2} 1/2 , C ab * ={(a*) 2+(b*) 2} 1/2 , h ab *=tg 1 b*/ a*, L* presented brightness. Results: After repeated firing, L* value of PFM , C ab * and L* value of dentin layer and h ab * value of opaque layer increased. Conclusion: The color of PFM after repeated firing may become brighter. The color change is resulted from the increase of L* and C ab * of dentin layer.

Objective: To study the influence of repeated firings on the PFM bond strength. Methods: 25 specimens of PFM in the diameter of 13.0 mm and thickness of (1.0?0.02) mm were prepared and fired at 920 ℃ for 1, 3, 5, 7 or 9 times(5 samples for each time). The remained porcelain rate(RPR) was measured by Mackert method and used to evaluate the bond strength.Results: After 3 firings, the RPR of PFM decreased obviously, and additional firings had no obvious effect on the RPR. Conclusion: 3 times firing or more may decrease the bond strength of PFM.

0.05,group 1 or group 2 vs group 3 P

AIM: To synthesize a number of novel heterocyclic compounds and screen for their biological activities. Sixteen title compounds were prepared. METHODS: These novel compounds were prepared by the reaction of 3-aryl/aryloxymethyl-4-amino-5-mercapto-1,2,4-triazoles with aryl carboxylic acids in the presence of phosphorus oxychloride. The structures of these compounds were confirmed by elemental analysis, IR, 1HNMR and MS. The reaction conditions for the synthesis had been investigated. All the compounds were screened for antimicrobial activity against bacteria S.aureus, E.coli and B.subilis. The concentration of the test compounds was 0.002%. The antibacterial activities of the test compounds were compared with those of penicillin and gentamicin. RESULTS: The results display that some of them possess strong biological activities.CONCLUSION: Syntheses of these novel heterocyclic compounds and study on their biological activities are very important and valuable in medicine.

OBJECTIVE:To investigate the protective effect of Polydatin on acute lung injury following endotoxic shock in rats.METHODS:Using a rat endotoxic shock model,animals were randomly divided into4groups∶sham operation group,en?dotoxic shock group,Polydatin treatment group and Polydatin pretreatment group.MAPs(mean artery pressures)were mea?sured at given time points.At the end of the experiment,the serum,the lung tissue,and the bronchoalveolar lavage fluid(BALF)were collected.The levels of lung coefficient,lung penetrating index(LPI),the protein concentration of BALF and the content of NOS in the lung tissue were measured.Furthermore,the histologic changes of the lung were observed under light micro?scope.RESULTS:In addition to prohibiting the dropping of MAP,Polydatin could mitigate the acute lung injury induced by endotoxin which increased the levels of lung coefficient,LPI,the protein concentration of BALF and the content of NOS in lung tissue.Enough morphological evidence could be found in pathological sections.Especially,the protective effects were more ob?vious in Polydatin pretreatment group.CONCLUSION:Polydatin has prophylactic and therapeutical effects on acute lung injury following endotoxic shock and the prophylactic effect is more marked than the therapeutic one.

Objective To study the effect of glutamine on hypermetabolism reaction and hormone secretion after severe burn injury. Methods Eighty-eight Wistar rats were inflicted with 30% total body surface area full thickness burns and randomly divided into two groups: namely burned control (B) and glutamine treatment(GLN) group. There was isonitrogenous and isocaloric intake in both groups, and rats of GLN and B groups were given glutamine and glycine at 1 0g/kg d, respectively. The following indices including the resting energy expenditure (REE), the levels of plasma cortisol, insulin and glucagon were determined. Results After burn injury, the REE, plasma cortisol,insulin and glucagons levels were significant increased in both groups. Compared with B group, the level of REE decreased and the ratio of insulin/glucagons increased in GLN group. Correlation analyses showed that REE had a negative correlation with insulin/glucagons ratio (r=-0 78,P

Objective To assess the sanitary quality of finished water produced by seawater desalination plant.Methods Using reverse osmosis for seawater desalination,the microbiological indexes,the levels of chloride and the pH values of finished water after seawater desalination were determined and then were assessed based on the National Method for Determination of Drinking Water(GB 5750-1985).Results After seawater desalination,the level of fluoride in finished water was 426 mg/L,the total count of bacteria of 3 finished water samples among 9 samples exceeded the standedard(350,300,4016/L),the pH valuer were qualified on the whole,except one lower value of 5.74 and a higher value of 8.94.Conclusicn After the treatment by seawater desalination system,the level of residual chloride in finished water was higher which approached the related highest limit ruled by National Sanitary Standard for Drinking Water,the microbiological indexes and pH values of finished water were unstable.