Abstract Purpose Patients with diabetes are vulnerable to myocardial I/R (ischaemia/reperfusion) injury, but are not responsive to IPO (ischaemic post-conditioning). We hypothesized that decreased cardiac Adiponectin (APN) is responsible for the loss of diabetic heart sensitivity to IPO cardioprotecton. Methods Diabetic rats were subjected to I/R injury (30 min of LAD occlusion followed by 120 min of reperfusion). Myocardial infarct area was determined by TTC staining. Cardiac function was monitored by a microcatheter. ANP, 15-F2t-isoprostane, nitrotyrosine and MDA were measured by assay kits. Levels of p-Akt, total-Akt and GAPDH were determined by Western Blot. Results Diabetic rats subjected to myocardial IR exhibited severe myocardial infarction and oxidative stress injury, lower APN in the plasma and cardiac p-Akt expression ( P <0.05). IPO significantly attenuated myocardial injury and up-regulated plasma APN content and cardiac p-Akt expression in non-diabetic rats but not in diabetic rats. Linear correlation analysis showed that the expression of adiponectin was positively correlated with p-Akt and negatively correlated with myocardial infarction area ( P <0.01). Conclusion Protective effect of IPO was tightly correlated with the expression of adiponectin, exacerbation of I/R injury and ineffectiveness of IPO was partially due to the decline of adiponectin and inactivation of Akt in diabetes mellitus.

The region model analysis is an important method for analyzing the interior fire hazard. Based on the mass conservation equation and energy conservation equation of the pre-flashover interior fire hazard development, the formulae required by computer programming are derived. VB is utilized as a tool for developing computation program with the aid of object programming idea to apply the mathematical modelling theories of the release rate of fire heat, plume and heat transfer. The relevant programming procedures and computation flow chart are presented. The program is verified through experimental data from Tianjin Fire Research Institute. As the computation of plumes is oversimplified, the thickness change of the smoke layer and the results obtained in the experiment vary considerably. The main advantage of the proposed computation model is that it is ease to be utilized for a variety of occasions.

El análisis del modelo de región es un importante método para analizar el riesgo de incendio interior. Sobre la base de la ecuación de conservación de energía y ecuación de conservación de la energía del desarrollo del peligro de incendio interior por combustión súbita, se derivan las fórmulas requeridas para el software informático. La herramienta VB se utiliza para el desarrollo de programas de computación con la ayuda de programación a objetos para aplicar las teorías de modelización matemática de la velocidad de liberación de calor fuego, penacho de fuego y transferencia de calor. Se presentan los procedimientos de programación pertinentes y diagrama de flujo de cálculo. El programa se verifica a través de datos experimentales del Instituto de Investigación de Incendios de Tianjin. Como se sobre-simplifica el cálculo de los penachos, el cambio de espesor de la capa de humo y los resultados obtenidos en el experimento varían considerablemente. La principal ventaja del modelo de cálculo propuesto es su facilidad para ser utilizado en una variedad de situaciones.