Objective:To observe the corrosion behavior of pure magnesium in different corrosive media,and explore the possible degradation mechanism.Methods:According to ASTM-G31-72 standard used simulated body fluid(SBF) and Dulbecco's modify Eagle medium(DMEM)for immersion media to immerse pure magnesium.Measured calcium,magnesium ion concentration and system pH changes in the different time point.The changes of material surface morphology were investigated by scanning electron microscopy,EDS and XRD.Results: After immersing 8 days,the samples in SBF could not observe the complete shape,while the samples' shape were completed in DMEM.The magnesium ion release quantity and calcium consumption in SBF solution are obviously higher than that of the DMEM solution.The changes of pH in two kinds of corrosion medium did not present too big difference,and the pH was maintained at about 10.0 finally.The product of pure magnesium which soaked in the two kinds of corrosion medium presented big difference.Samples' surface in the SBF system generated magnesium hydroxide,and emerged a small amount of magnesium phosphate precipitation.While in DMEM,there has been a lot of magnesium monohydrogen phosphate,magnesium phosphate,and a small amount of magnesium hydroxide crystals.Conclusion:The SBF system of the corrosion rate was significantly higher than DMEM.Pure magnesium corrosion products generated differently at different time points in the SBF system and DMEM.

BACKGROUND:The bilirubin adsorbent column is used to reduce the high concentration of bilirubin in the blood of patients.During the healing process,the resin particle in the column has a large-scale and long-time contact with the blood of patients.Therefore,the evaluation of blood compatibility of bilirubin adsorbent column is very important.OBJECTIVE:To assess the blood compatibility of a bilirubin adsorbent column.METHODS:Commercially available bilirubin adsorbent column was used as product control.The resin particles in test and control bilirubin adsorbent column were put into silicified glass tubes,respectively.The empty silicified glass tubes were used as blank control.The fresh human plasma was put into silicified glass tubes in three groups and cultured on the rotary incubator in impermeable incubator at the rate of 30 r/min under 37 ℃.After 3 minutes,the plasma was taken out to detect the prothrombin time,activated partial thromboplastin time,fibrinogen and complement hemolysis CH50.The whole process was repeated three times.RESULTS AND CONCLUSION:Compared with the blank control group,prothrombin time and activated partial thromboplastin time in the control group and experimental group were prolonged;concentration of fibrinogen and complement hemolysis CH50 in the control group and experimental group were decreased,but the difference was reducing with the increasing plasma-resin particle contact processes.Compared with control group,values of prothrombin time,activated partial thromboplastin time,fibrinogen in the experimental group were closer to those in the blank control group in three determinations.In three determinations,complement hemolysis CH50 concentration in the experimental group was larger than that in the control group at first,then insignificantly different from the control group and at last smaller than that in the control group.Results indicated that:①The blood compatibility of the resin particles was improved with increasing plasma-resin particle contact processes.②The resin particle in the test bilirubin adsorbent column has fewer effect on the coagulation system than the control product.In first adsorption,the influence of the test resin particle on the complement system was smaller than the control product,but the control product had a faster increase in comparison with complement in later two adsorption processes.