http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The Effects of Melatonin on Cisplatin-Induced Renal Cortical Cell Injury in Rabbits
Chunghui Kim,Jin Han,Nari Kim,Juhee Park,Youngchurl Yang,Euiyong Kim 대한생리학회-대한약리학회 2001 The Korean Journal of Physiology & Pharmacology Vol.5 No.3
<P> Melatonin, a pineal gland hormone, is believed to act as an antioxidant via the stimulation of radical detoxifying enzymes and scavenging of free radicals. In this study, effects of <I>in vitro </I>and<I> in vivo</I> treatments of melatonin on the cisplatin-induced lipid peroxidation, LDH release and plasma creatinine were determined in rabbit renal cortical cells. The level of malondialdehyde (MDA) was assayed as an index of lipid peroxidation and the level of LDH release as an indicator of cellular damage. In <I>in vitro</I> studies, cisplatin increased the levels of MDA and LDH release in a concentration-and time-dependent manner. Melatonin inhibited the cisplatin-induced lipid peroxidation and LDH release in a concentration-dependent manner. The minimal effective concentration of melatonin that significantly reduced the 300μM cisplatin- induced lipid peroxidation and LDH release was 1 mM. In <I>in vivo</I> studies, the levels of lipid peroxidation and LDH release in renal cortical cells increased significantly 24 or 48 hours after a single injection of cisplatin (6 mg/kg). When the cisplatin-injected rabbits were pretreated with 10 mg/kg of melatonin, a significant reduction in both lipid peroxidation and LDH release was observed. The plasma creatinine level increased from 0.87⁑0.07 mg/dl in control to 6.33⁑0.54 mg/dl in cisplatin-injected rabbits (P<0.05). Melatonin partially prevented the increase in serum creatinine level (1.98⁑0.11 mg/dl) by cisplatin (P<0.05). In the proximal tubules from cisplatin-treated group, tubular cells had microvilli of variable heights. Necrotic debris was seen in tubular lumens. In most of cells, the mitochondria and lysosomes were increased in frequency. The endocytic vacuoles were not prominent and distribution of the brush border was irregular and shortened. These cisplatin-induced morphological changes were moderate in the melatonin-pretreated group. These results suggest that the toxicity of cisplatin is associated with the generation of reactive oxygen free radicals and that melatonin is a powerful antioxidant, which prevents some of the adverse effects of cisplatin.
Warm-up characteristics of a gasoline engine with the exhaust heat recovery system
( Chunghui Kim ),( Sangwook Han ),( Hyunchul Kim ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-
The exhaust heat recovery system uses heat energy of the exhaust gas for the heat exchange between the exhaust gas and the coolant at the cold start duration. It shortens the warm-up time and thus improve the fuel economy due to the initial friction loss reduction. In this study, the warm-up characteristics of a gasoline engine with exhaust heat recovery system (EHRS) was analyzed in the engine and the vehicle, respectively. In the engine test, the coolant temperature of EHRS outlet was higher than that of inlet at the beginning of cold start. This was because of heat transfer from exhaust gas to coolant. However, its effect is not significant in the low load condition because heat from exhaust gas was used to warm up the EHRS itself and coolant quantity also increased. In high load condition, on the other hand, it resulted in fast warm-up of the coolant by the sufficient heat energy for the warm-up. In addition, the various parametric studies were conducted and analyzed in the engine test. In the vehicle test, both EHRS and ATF Warmer/Cooler were installed for better fuel economy. The results showed the remarkable increase in ATF temperature and thus improved the fuel economy at the FTP-75 mode.