Objective： To observe the electrocardiogram （ECG） and heart rate in a rabbit model ofhyperkalemia induced by potassium chloride, and provide theoretical and experimental reference for timely diagnosis of hyperkalem...Objective： To observe the electrocardiogram （ECG） and heart rate in a rabbit model ofhyperkalemia induced by potassium chloride, and provide theoretical and experimental reference for timely diagnosis of hyperkalemia clinically. Methods： Forty rabbits were randomly assigned into four groups. 0.9% isotonic saline solution was perfused in the group I , while 1.0%, 4.0% and 10.0% potassium chloride solutions were perfused in the other groups, respectively, to induce hyperkalemia. Results： The changes of serum potassium, ECG and heart rate before perfusion were significantly （P〈 0.05） different from those after perfusion in the other groups compared with group I . The effect of ECG variability rates was well consistent （Kappa = 0.724, P〈0.01） with that of serum potassium on diagnostic tests in the other groups. The area under ROC curve in diagnosis effect of ECG variability rates and sermn potassium on hyperkalaemia was much significantly larger （P〈0.01 and P〈0.05） compared with 0.5. There was asignificantly positive correlation between ECG variability rates and serum potassium （r= 0.865, P〈0.05 for bilateral Pearson test）. There was certain positive correlation between heart rate and serum potassium, but the correlation was poor （r= 0.526, R2=0.277）. Conclusion： A combination of serum potassium, ECG variability rates and heart rate should be considered and analyzed by synthesis to establish an accurate and timely diagnosis for hyperkalemia.展开更多
As an efficient cooling method for high heat flux field,spray cooling has a great application potential on aircraft directed energy weapon cooling.Based on previous research results,an experimental system of open-loop...As an efficient cooling method for high heat flux field,spray cooling has a great application potential on aircraft directed energy weapon cooling.Based on previous research results,an experimental system of open-loop spray cooling was established,and the potassium chloride aqueous solutions and ethylene glycol aqueous solutions with different mass fractions were applied to investigate the influence of different additives on spray cooling system performance.Besides,theoretical analysis was conducted according to the droplet breakage principle and the characteristic parameters of fluid mechanics.The results indicate that heat transfer can be enhanced by adding potassium chloride up to a certain concentration and then decrease with higher concentration.Heat transfer is deteriorated with the increase of ethylene glycol concentration.Both of the two additives can reduce the freezing point of the system,and ethylene glycol is preferred to improve the application range of the system in consideration of the corrosion of salt solution.展开更多
基金Supported by Natural Science Foundation of Chengdu Medical College(CYZ09-004)The "Challenge Cup" Sichuan Undergraduate Curricular Academic Science and Technology Works(CT11D-1006)
文摘Objective： To observe the electrocardiogram （ECG） and heart rate in a rabbit model ofhyperkalemia induced by potassium chloride, and provide theoretical and experimental reference for timely diagnosis of hyperkalemia clinically. Methods： Forty rabbits were randomly assigned into four groups. 0.9% isotonic saline solution was perfused in the group I , while 1.0%, 4.0% and 10.0% potassium chloride solutions were perfused in the other groups, respectively, to induce hyperkalemia. Results： The changes of serum potassium, ECG and heart rate before perfusion were significantly （P〈 0.05） different from those after perfusion in the other groups compared with group I . The effect of ECG variability rates was well consistent （Kappa = 0.724, P〈0.01） with that of serum potassium on diagnostic tests in the other groups. The area under ROC curve in diagnosis effect of ECG variability rates and sermn potassium on hyperkalaemia was much significantly larger （P〈0.01 and P〈0.05） compared with 0.5. There was asignificantly positive correlation between ECG variability rates and serum potassium （r= 0.865, P〈0.05 for bilateral Pearson test）. There was certain positive correlation between heart rate and serum potassium, but the correlation was poor （r= 0.526, R2=0.277）. Conclusion： A combination of serum potassium, ECG variability rates and heart rate should be considered and analyzed by synthesis to establish an accurate and timely diagnosis for hyperkalemia.
文摘As an efficient cooling method for high heat flux field,spray cooling has a great application potential on aircraft directed energy weapon cooling.Based on previous research results,an experimental system of open-loop spray cooling was established,and the potassium chloride aqueous solutions and ethylene glycol aqueous solutions with different mass fractions were applied to investigate the influence of different additives on spray cooling system performance.Besides,theoretical analysis was conducted according to the droplet breakage principle and the characteristic parameters of fluid mechanics.The results indicate that heat transfer can be enhanced by adding potassium chloride up to a certain concentration and then decrease with higher concentration.Heat transfer is deteriorated with the increase of ethylene glycol concentration.Both of the two additives can reduce the freezing point of the system,and ethylene glycol is preferred to improve the application range of the system in consideration of the corrosion of salt solution.
