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High temperature oxidation of ferritic stainless steel 21Cr-0.6Mo-Nb-Ti was carried out isothermally at 1100 oC under different water vapour content conditions in an electrical furnace. Water vapour does accelerate the formation of oxide scale of stainless steel 21Cr-0.6Mo-Nb-Ti, however, it is not significant. Some oxide grains consist of spinel crystal structure, which should be spinel Manganese Chromite. In dry air atmosphere, the grain of the spinel is more and bigger than that in wet air. No breakaway oxidation occurs in the experiment indicating that 21Cr-0.6Mo-Nb-Ti has very high oxidation resistance, which might be contributed by the formation of MnCr2O4 and compact protective chromia. In addition, continuous silica formed along and accumulated at the oxide metal interface performs like a diffusion barrier.

Objective: To evaluate the effect of Xiongshao Capsule in preventing clinical and angiographic restenosis after coronary angioplasty or/and stenting. Methods: The total of 108 coronary heart disease patients with successful coronary angioplasty or/and stenting were randomly divided into the control group (55 cases, routine treatment) and the XS group (53 cases, routine treatment combined with XS). The recurrence of angina, clinical end-point events, changing of blood-stasis syndrome score (BSSS) and coronary angiography within 6 month after coronary angioplasty or/and stenting were observed. Results: Follow-up angiography was performed in 42 patients including 18 cases in the XS group (restenosis was observed in 7 patients) and 24 cases in the control group (restenosis was observed in 17 patients), there was significant difference between the occurrence of restenosis in XS and that in control group (P< 0.05). The occurrence of clinical end-point events (death, nonfatal target lesion myocardial infarction, coronary artery bypass graft surgery, or repeat target-vessel angioplasty) in the XS group (18.8%) was significantly lower than that in the control group (40%)(P<0.05). The recurrent angina was observed in 13 cases in the XS group, there was significant difference as compared with 27 cases in the control group (P<0.05). There was also remarkable significance for the difference of base-line and follow-up BSSS between groups (P< 0. 01). Logistic multivariate stepwise regress analysis and multivariate regress analysis of the related factors with restenosis confirmed by coronary angiography showed that, the base-line BSSS and the difference of base-line and follow-up BSSS were important influencing factors on the occurrence of restenosis after interventional treatment (P< 0.05). Conclusion: XS could markedly reduce the occurrence of angiographic restenosis, clinical end-point events and recurrent angina, improve condition of blood-stasis after coronary angioplasty or/and stenting. The severity of blood-stasis syndrome was an important influencing factor on the occurrence of restenosis. It still needs to be further demonstrated by large-scale, double-blinded, randomized and controlled study.