The hardness, compressive strength and cure depth are important indices of the composite resin. This investigation was made with regard to the effects of silicon carbide on the cure depth, hardness and compressive strength of the light-curing composite resin. Different amounts of silicon carbide were added to the light-curing composite resin, which accounted for 0 wt%, 1 wt%, 0.6 wt%, 0.3 wt%, 0.1 wt%, 0.05 wt% and 0.005 wt% of the composite resin, respectively. The hardness, compressive strength and cure depth of the six afore-mentioned groups of composite resin were measured by the vernier caliper, the vickers hardness tester and the tensile strength of machine, respectively. The results showed that silicon carbide improved the hardness and compressive strength of the light-curing composite resin,when the concentration was 0.05 wt%. And the cure depth was close to that of control.
Carbon Compounds, Inorganic ; pharmacology ; Composite Resins ; chemistry ; Compressive Strength ; drug effects ; Dental Materials ; chemistry ; Hardness ; drug effects ; Silicon Compounds ; pharmacology

Objective To investigate the empty nest elderly's willingness of the five factors of the senior cohousing pension model, and provide reference for the localization of this pension model in China. Methods Totals of 550 empty nest elderly from Hangzhou were selected and investigated by questionnaire about the general information and the willingness. Results Among the empty nest elderly, 61.25% were willing to choose the senior cohousing pension model. The elderly put forward specific requirements to residence, population, financial support, health care and management operation. Conclusions In our country, it should be taken full account of the specific willingness of the elderly to residence,population, financial support, health care, and management operation when running the pension model of the senior cohousing.

Objective To compare the diagnostic validity between the delirium rating methods (confusion assessment method,CAM) and the nurse used delirium screening scale(nursing delirium screening scale,NU-DESC)for the old dementia patients. Methods Patients who met the criteria for DSM-IV dementia diagnosis,the CAM and the NU-DESC was used to assess at 0,2,4,6,8 weeks after admission,and the DSM-IV was used as the gold standard diagnosis criteria for delirium. To compare the diagnostic sensitivity, specificity and consistency between the two evaluation tools using the ROC curve analysis and diagnostic consistency test. Results The criticality value of the CAM to estimate dementia patients with delirium was 26,with sensitivity 0.97,specificity 0.82,and the Kappa of the consistent with DSM-IV diagnosis was 0.60;the criticality value of the NU-DESC to estimate dementia patients with delirium was 3,with sensitivity 0.81, specificity 0.77,and the Kappa of the consistent with DSM-IV diagnosis was 0.45. For mild and moderate dementia patients,the diagnostic validity of the two tools was closer;for the severe dementia patients,the diagnostic validity of the CAM was better than the NU-DESC. Conclusions The sensitivity and specificity of the CAM used in the dementia patients were higher,the CAM was better than the NU-DESC,and could be used to screen for senile dementia patients with delirium;the NU-DESC could be used to estimate the mild and moderate dementia patients.