The pyrolysis behaviors of foam patterns have critical influences on fluid morphology and defect formation in Lost Foam Casting(LFC). The pyrolysis behaviors of expanded polystyrene(EPS) and styrenemethyl methacrylate...The pyrolysis behaviors of foam patterns have critical influences on fluid morphology and defect formation in Lost Foam Casting(LFC). The pyrolysis behaviors of expanded polystyrene(EPS) and styrenemethyl methacrylate(St-MMA) foams were compared using synchronous thermal analysis(STA), which was performed under argon atmosphere at different heating rates(from 10 to 40 K·min^(^(-1))). The degradation heat was calculated by integrating DSC curves. Results show that the calculated degradation heat of St-MMA(605.28 J·g^(-1)) was significantly lower than that of EPS(706.71 J·g^(-1)). Furthermore, the non-isothermal iso-conversional method was used to determine the pyrolysis apparent activation energies of EPS and St-MMA, and results show that the activation energy of St-MMA(200.36 kJ·mol^(-1)) was apparently higher than that of EPS(167.92 kJ·mol^(-1)). These calculated results indicate that the weight loss rate of EPS is greater than St-MMA in the pyrolysis process. In addition, the apparent activation energies at various pyrolysis stages demonstrate that the pyrolysis reactions of EPS and St-MMA may involve physical and chemical changes in the decomposition layer of the LFC process.展开更多
In the present study, the therapeutic effect of acupuncture at Shuigou(GV 26), Neiguan (PC 6) and Zusanli (ST 36) in treatment of 30 cases of ischemic cerebral apoplexy patients and its action on plasma βEP (endorphi...In the present study, the therapeutic effect of acupuncture at Shuigou(GV 26), Neiguan (PC 6) and Zusanli (ST 36) in treatment of 30 cases of ischemic cerebral apoplexy patients and its action on plasma βEP (endorphine) level were observed. After treatment, of the 30inpatients, 16 cases were cured basically, 9 had marked improvement, 4 had slight improvement and the rest one had no any changes. The significantly effective rate was 83.3% and the total effective rate was 96.7%. Before acupuncture treatment, the content of plasma βEP inpatients with ischemic stroke increased significantly in comparison with that of normal group (P<0.01). While after treatment, plasma βEP level decreased to approach to the normal level, which may be one of the mechanisms of acupuncture in alleviating stoke patients.展开更多
Objective: To study the mechanisms of acupuncture in treatment of acute cerebral infarction. Methods: 90 SD rats were randomly divided into normal control group (n=10), model group (n=40) and electroacupuncture (EA) g...Objective: To study the mechanisms of acupuncture in treatment of acute cerebral infarction. Methods: 90 SD rats were randomly divided into normal control group (n=10), model group (n=40) and electroacupuncture (EA) group (n=40). Shuigou (GV 26), bilateral Neiguan (PC 6) and Zusanli (ST 36) were stimulated with EA for 20 min. Acute cerebral infarction (ACI) was produced by blocking blood flow of the cerebral middle artery. Changes of β EP content in the brain tissue after ACI and EA were detected by radioimmunoassay (RIA). Results: 24 hour after ACI, plasma β EP content increased significantly to 1120.41±33.79 ng/L from 401.72±266.47 ng/L before ACL. While after acupuncutre, the increased β EP content lowered evidently in comparison with that of model group but was close to that of normal group. Conclusion: Acupuncture may adjust the neuroendocrine disturbance in rats with acute cerebral infarction to minimize the injury of the brain tissue.展开更多
文摘The pyrolysis behaviors of foam patterns have critical influences on fluid morphology and defect formation in Lost Foam Casting(LFC). The pyrolysis behaviors of expanded polystyrene(EPS) and styrenemethyl methacrylate(St-MMA) foams were compared using synchronous thermal analysis(STA), which was performed under argon atmosphere at different heating rates(from 10 to 40 K·min^(^(-1))). The degradation heat was calculated by integrating DSC curves. Results show that the calculated degradation heat of St-MMA(605.28 J·g^(-1)) was significantly lower than that of EPS(706.71 J·g^(-1)). Furthermore, the non-isothermal iso-conversional method was used to determine the pyrolysis apparent activation energies of EPS and St-MMA, and results show that the activation energy of St-MMA(200.36 kJ·mol^(-1)) was apparently higher than that of EPS(167.92 kJ·mol^(-1)). These calculated results indicate that the weight loss rate of EPS is greater than St-MMA in the pyrolysis process. In addition, the apparent activation energies at various pyrolysis stages demonstrate that the pyrolysis reactions of EPS and St-MMA may involve physical and chemical changes in the decomposition layer of the LFC process.
文摘In the present study, the therapeutic effect of acupuncture at Shuigou(GV 26), Neiguan (PC 6) and Zusanli (ST 36) in treatment of 30 cases of ischemic cerebral apoplexy patients and its action on plasma βEP (endorphine) level were observed. After treatment, of the 30inpatients, 16 cases were cured basically, 9 had marked improvement, 4 had slight improvement and the rest one had no any changes. The significantly effective rate was 83.3% and the total effective rate was 96.7%. Before acupuncture treatment, the content of plasma βEP inpatients with ischemic stroke increased significantly in comparison with that of normal group (P<0.01). While after treatment, plasma βEP level decreased to approach to the normal level, which may be one of the mechanisms of acupuncture in alleviating stoke patients.
文摘Objective: To study the mechanisms of acupuncture in treatment of acute cerebral infarction. Methods: 90 SD rats were randomly divided into normal control group (n=10), model group (n=40) and electroacupuncture (EA) group (n=40). Shuigou (GV 26), bilateral Neiguan (PC 6) and Zusanli (ST 36) were stimulated with EA for 20 min. Acute cerebral infarction (ACI) was produced by blocking blood flow of the cerebral middle artery. Changes of β EP content in the brain tissue after ACI and EA were detected by radioimmunoassay (RIA). Results: 24 hour after ACI, plasma β EP content increased significantly to 1120.41±33.79 ng/L from 401.72±266.47 ng/L before ACL. While after acupuncutre, the increased β EP content lowered evidently in comparison with that of model group but was close to that of normal group. Conclusion: Acupuncture may adjust the neuroendocrine disturbance in rats with acute cerebral infarction to minimize the injury of the brain tissue.
