• Journal of Chest Surgery
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• v.28 no.5
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• pp.437-442
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• 1995

We developed an experimental model of brain death using dogs. Brain death was caused by increasing the intracranial pressure[ICP suddenly by injecting saline to an epidural Foley catheter in five female mongrel dogs[weight, 20-25Kg .Hemodynamic and electrocardiographic changes were evaluated continuously during the process of brain death. 1. Abrupt rise of ICP after each injection of saline followed by a rapid decline to a new steady-state level within 15 minutes and the average volume required to induce brain death was 7.6$\pm$0.8ml.2. Body temperature, heart rate, mean pulmonary arterial pressure, left ventricular[LV enddiastolic pressure and cardiac output was not changed significantly during the process of brain death, but there was an increasing tendency.3. Mean arterial pressure and LV maximum +dP/dt increased significantly at the time of brain death.4. Hemodynamic collapse was developed within 140 minutes after brain death.5. Marked sinus bradycardia followed by junctional rhythm was seen in two dogs and frequent VPB`s with ventricular tachycardia was observed in one dog at the time of brain death. Hyperdynamic state develops and arrhythmia appears frequently at the time of brain death. Studies on the effects of brain death on myocardium and its pathophysiologic mechanism should be followed in the near future.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1143-1152
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• 2019

In order to study the solubilization of aniline by cationic surfactants (DTAB, TTAB and CTAB), the solubilization constant (K_s) and thermodynamic functions were measured and calculated by using the UV-Vis method. The solubilization constants of aniline with the change of temperature were measured, and the effects of addition of ionic salts and organics on the solubilization constants were investigated. These effects of additives and temperature changes were compared and analyzed for each type of surfactant, and the solubilization of aniline was analyzed microscopically by comparing and evaluating the thermodynamic functions obtained from the solubilization constants. As a result, the Gibbs free energy and enthalpy changes were both negative and the entropy changes were positive within the measured range for the solubilization of aniline by cationic surfactants. The solubilization constant value decreased with increasing temperature and increased with increasing carbon chain length of the surfactant. As the concentration of ionic salts increased, the Gibbs free energy change increased at first and then decreased. In n-butanol solution, the Gibbs free energy change tended to increase continuously with increasing the concentration of n-butanol.