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Propylthiouracil 투여에 의한 갑상선 기능저하 흰쥐 조직에서 알코올 탈수소효소 활성의 변화
백상현,김동선,이창범,박용수,안유헌,김태화,기춘석,강주섭 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.2
Background: Thyroid hormone has been known to affect hepatic alcohol dehydrogenase (ADH) activity. Although the liver is the principal site of ethanol metabolism, stomach is also responsible in part for ethanol oxidation. The effects of thyroid hormone on ADH activity in gastric mucosa and other tissues of rats had not been previously examined. Method: The effects of thyroid hormone on liver, stomach, lung, and kidney ADH activities (nM of NADH/min/mg of cytosolic protein) have been investigated in male Sprague Dawley rats treated with propylthiouracil (50 mg/kg) for 14 days. Results: Whereas hepatic ADH activities were not changed by treatment with PTU(42.9(8.6 vs 45.2 (10.1), gastric ADH activities in PTU-treated rats increased by 258.8% of control rat (6.3 ( 0.6 vs 2.2 ( 1.2, p〈0.001). In the activities of other tissues, PTU treatment decreased lung ADH activity by 59.7% of control, and increased kidney ADH activities by 247.1% of control rats. Conclusion: These data suggest that hypothyroidism causes an increase of gastric alcohol metabolism, and that the increase of gastric ADH activity can partly restore the first pass metabolism of ethanol in hypothyroid rats.
윤종학,여만구,김상헌 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.3
This study is focused on the prediction of appropriate tool life by clarifying the correlation between progressive tool wear and AE(Acoustic Emission) signals, while cutting stainless steel by end mill on te machining center. The results of this study were that RMSAE tends to increase linearly along with the incrase of the cutting speed, and it was more sensitive to depth of cut than to the variation of feed rate at the same cutting conditions, and RMSAE increases around 0.21mm flank wear hereby AE-HIT also increases. AE signals depend upon tool wear and fracture from the above results. Therefore, the AE signals can be utilized in order to monitor the tool condition.
Solution Viscosity and Relative Reactivity of Branched and Linear Polycarbonates
Kim, Sang-Pil,Lee, Bong-Hee,Kim, Sang-Hern,Kim, Whan-Gi The Korean Society of Applied Science and Technolo 2000 한국응용과학기술학회지 Vol.17 No.2
The relative reactivities of branched and linear polycarbonates were investigated by measuring unreacted chloroformate concentration. It was found that the polymerization for the branched polymer proceeded ca. 10 times faster than that for the linear polymers. The effect of catalyst on a condensation step was studied by changing the amount of TEA (triethylamine) at $t_{0}$ and $t_{60}$ with keeping constant amount of TEA. The viscosity average molecular weight for the obtained branched polycarbonates were measured and compared with those of linear polycarbonates. It was found that the viscosity molecular weights of the obtained polymers decreased nonlinearly as wt % of added oligomer increased. The solution viscosities in methylenechloride for linear and branched polycarbonate increased nonlinearly as the content of polymer increased.
Ferroelectric Properties of PZT Thin Films Deposited on ZnO/Si Substrates
Sang Hern Lee,Jong Pil Kim,Joon Young Heo,Min Ki Ryu,Min Su Jang,Seong Ryul Kim 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV
Pb(Zr0:52Ti0:48)O3[PZT] thin lms have been prepared by the sol-gel technique on ZnO/Si substrates for nonvolatile memory operation of a metal-ferroelectric-semiconductor eld eect transistor. ZnO lms were deposited by rf-sputtering. Charge storage characteristics have been investigated in metal-ferroelectric-insulator-semiconductor (MFIS) memory structure with ZnO insulator buer layer. The PZT thin lms showed the ferroelectric hysteresis loop with remanent polarization of 20 C/cm2 and coercive eld of 140 kV/cm. The dielectric constants of PZT and ZnO were 200-650 and 16.5, respectively. The density of surface states of the ZnO/Si interface was estimated from the slope of the C-V characteristics to be about 1:421011 eV..1cm..2. The memory window of the MFIS structure was characterized with a capacitance-voltage (C-V ) method.l?
Methanolysis of Poly(ethylene-2,6-naphthalenedicarboxylate)
Kim, Sang Hern,Chun, Jong Han,Han, Jong Soo 한국공업화학회 1998 Journal of Industrial and Engineering Chemistry Vol.4 No.2
Through the methanolysis of polyethylene-2,6-naphthalene dicarboxylate) (PEN), 2,6-dimethylnaphthalate (DMN) was obtained from the filtercake, small amounts of DMN and p-methoxycarbonyl-2-hydroxyethyl naphthalate (P-MCHEN) were obtained from the filtrate residue. To convert P-MCHEN to DMN, methanolysis was performed again under various conditions. With increasing amounts of MeOH and catalyst, the conversion of DMN to P-MCHEN increased. It was found that the recovery yield of DMN from PEN waste improved by using of zinc acetate as a second catalyst component which is capable of converting the by-product (P-MCHEN) formed in the methanolysis into DMN.
Synthesis and Characterization of Aromatic Polyamideamide-imide and Polyamide-imide copolymers
Kim, Sang-Hern The Korean Society of Applied Science and Technolo 2008 한국응용과학기술학회지 Vol.25 No.2
The polyamide-amide-imide (PAAI) was synthesized by reacting 4,4'-diaminobenzanilide (DBA) with trimellitic anhydride chloride using a two-stage heating. The precursor of polyamide-acids was formed at first stage and followed by the formation of imide of PAAI. Two polyamide-imides (PAIs) were prepared from benzidine (BZ) or 4,4'-diaminodiphenylether (DPE) with trimellitic anhydride chloride. These three polymers had glass transition temperature in the temperature range of $240-250^{\circ}C$. X-ray data were obtained on thin film specimens cured at $250^{\circ}C$. There was a minimal kind of short-range order consisting of the most probable distances between neighboring chains. The average segmental spacing of short-range order decreased in the order of polymers obtained from 4,4'-diaminobenzanilide (DBA), polyamide-imide, and 4,4'-diaminodiphenylether (DPE). The imidization of three polyamide-imides was confirmed by $^{15}N$ MAS NMR and FT-IR spectroscopy. $^{15}N$ NMR spectrum of cured polyamide-imide showed imide $^{15}N$ peak, thereby providing an evidence for the imidization of three polyamide-imides.
Solution Vicosity and Relative Reactivity of Branched and Linear Polycarbonates
Kim, Sang Hern,Kim, Whan Gi,Kim, Sang Pil,Lee, Bong Hee 한국유화학회 2000 한국응용과학기술학회지 Vol.17 No.2
The relative reactivities of branched and linear polycarbonates were investigated by measuring unreacted chloroformate concentration. It was found that the polymerization for the branched polymer proceeded ca. 10 times faster than that for the linear polymers. The effect of catalyst on a condensation step was studied by changing the amount of TEA (triethylamine) at t_0 and t_60 with keeping constant amount of TEA. The viscosity average molecular weight for the obtained branched polycarbonates were measured and compared with those of linear polycarbonates. It was found that the viscosity molecular weights of the obtained polymers decreased nonlinearly as wt % of added oligomer increased. The solution viscosities in methylenechloride for linear and branched polycarbonate increased nonlinearly as the content of polymer increased.