전기수용설비의 중성선 영상분고조파전류저감장치

강창원,최길수,한성배,김범수,정연해,이기철,Kang, Chang-Won,Choi, Gil-Soo,Han, Sung-Bae,Kim, Bum-Soo,Chung, Yeon-Hae,Lee, Ki-Cheol 한국전기기술인협회 2001 電力技術人 Vol.228 No.8

Wide use of non-linear loads such as personal computers, monitors, laser printers, variable speed drives, UPS systems and other electronic equipment have led to harmonics becoming #1 issue in the electrical industry today. Commercial and Industrial building power distribution systems, designed for the old, linear-style loads especially when found in high densities. Some common power system problems include overloaded neutral conductors, overheated distribution transfOlmers, high neutral-to-ground voltage, poor power factor and distortion of the voltage waveform supplying these loads. The power quality problems, particularly high voltage distortion, have been known to cause equipment downtime due to malfunctions and component failure.

심방이뇨호르몬의 분비조절에 있어서 superoxide anion의 영향

강창원,김남수,이호일,Kang, Chang-won,Kim, Nam-soo,Lee, Ho-il 대한수의학회 1996 대한수의학회지 Vol.36 No.1

Atrial Natriuretic Peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties of vascular smooth muscle. Specific chemical modulator responsible for the ANP secretion has not yet been found. Although atrial stretch of stretch-release is to be a major stimulus for the secretion of ANP, the precise mechano-molecular transduction mechanism responsible for its evoked secretion remains to be elucidated. It is interested to clarify the effect of superoxide anion in the stretch-induced ANP secretion. In order to investigate the effectg of $H_2O_2$ in the regulation of ANP secretion, a perfused model of left atrium of rats was used. The results obtained were as follows; 1. The ANP secretion and the extracellular fluid(ECF) translocation were accentuated by the effect of repetitive atrial distension-reduction volume at atrial pressure($4cmH_2O$). 2. The dilution curve showed to be in parallel between pure atriopeptin III (AP III) and perfusated buffer. 3. $H_2O_2(5{\times}10^{-4}M)$ accenturated a strectch-release induced increase of the ANP secretion. The amount of released ANP was significantly(p<0.01) increased. These results suggest that the superoxide anion may be involved in the regulatory mechanism of mechanically activated ANP release.

특별기고 - 생존을 넘어 성장을 위한 기본전략

강창원,Kang, Chang-Won 한국사료협회 2009 飼料 Vol.40 No.-

Effects of activation of protein kinase C on the regulation of atrial natriuretic peptide(ANP) by isolated perfused left atria

강창원,강형섭,이호일,Kang, Chang-won,Kang, Hyung-sub,Lee, Ho-il The Korean Society of Veterinary Science 1997 대한수의학회지 Vol.37 No.4

심방근 세포는 심방이뇨호르몬을 합성, 저장 그리고 분비하며, 세포내외 이온의 농도, 수분균형 및 혈압 등을 조절하는 것으로 알려져 있다. 또한 심방근의 인장자극에는 Atrial Natriuretic Peptide(ANP)를 2단계(분비, 유리)의 과정으로 이루어져 있으며, 이에 따른 심방이뇨호르몬의 분비 조절기전에 대하여서는 명확히 알려져 있지 않다. 따라서 본 연구는 백서의 심방근 적출관류 모델을 이용하여 protein kinase C와 ANP 조절의 상관관계를 밝히고 분비와 유리의 과정중 어떠한 과정을 이용하여 분비자극에 영향을 주는지를 관찰하기 위하여 본 실험을 실시하였다. PKC 활성제인 PMA(phorbol 12-mystrate 13-acetate)는 ANP의 유리를 현저하게 증가시켰으며, PKC 억제제인 H-7(1-(5-isoquinoline sulfonyl)-2-methyl piperazine dihydrochlo-ride)에 의해 유리를 억제시켰다. PMA와 H-7을 동시에 처리한 경우 PMA에 의하여 증가된 ANP의 유리가 H-7에 의하여 차단됨을 관찰할 수 있었다. 따라서 백서의 관류 심방에서의 ANP 분비 증가는 PKC 활성화에 의하여 이루어지며, ANP분비의 2단계중 ANP 유리에 영향을 줌을 알 수 있었다.

백서 간 관류모델에서 forskolin이 Insulin like growth factor-I의 분비에 미치는 효과

강창원,이대열,이호일,Kang, Chang-won,Lee, Dae-yeol,Lee, Ho-il 대한수의학회 1999 대한수의학회지 Vol.39 No.5

The insulin-like growth factor-I(IGF-I) is an important metabolic factor involved in cell growth and metabolism. Although secretion of IGF-I in rat liver is regulated by growth hormone, the effects of forskolin, adenylate cyclase activator, on secretion of IGF-I have not been reported. Therefore, a modified perfused rat liver model was used to investigate the regulatory effects of forskolin on IGF-I secretion in this experiment. The results were summerized as follows : 1. Modified perfused rat liver model was not changed to aspartate aminotransferase(AST), alanine aminotransferase(ALT) and lactic dehydrogenase(LDH) secretion in time. 2. The IGF-I secretion in hepatic cell was increased by forskolin($10^{-5}$, $10^{-6}$ and $10^{-7}M$) in a dose-dependent manner as compared with those of the controls, and significantly increased by $10^{-5}$ and $10^{-6}$ forskolin(p < 0.05). 3. Secretion of glucose in hepatic cell significantly was decreased by $10^{-5}$ forskolin as compared with those of controls(p < 0.05). These results suggest that forskolin may be involved in the regulation of IGF-I secretion in the perfused rat liver.

심방 이뇨호르몬의 분비조절에서 Ca²⁺이 protein kinase C 활성화에 미치는 영향

강창원,김진상,이호일,Kang, Chang-won,Kim, Jin-shang,Lee, Ho-il 대한수의학회 1999 대한수의학회지 Vol.39 No.5

Atrial natriuretic peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties on vascular smooth muscle. Specific chemical modulator in response for the ANP secretion has not been found yet. Therefore, we have investigated the role of $Ca^{2+}$ responsible for the regulation of ANP induced by protein kinase C(PKC) on mechanically stretch-induced ANP secretion in the rat atria. The results obtained were as follows ; 1. ANP secretion and ANP concentration were increased to more in $Ca^{2+}$-free buffer than in the Kreb-Henseleit buffer on mechanically stretch-induced ANP secretion(p < 0.05), but extracellular fluid translocation(ECF) was not significant. Phorbol 12-myristate 13-acetate(PMA, $10^{-7}M$) induced ANP secretion and ANP concentration in $Ca^{2+}$-free buffer shown to more accentuate on mechanically stretch-induced ANP secretion than in the $Ca^{2+}$-free buffer(p < 0.05), but ECF translocation was not significant. 2. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the Kreb-Henseleit buffer were shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the Kreb-Henseleit buffer(p < 0.05), but ECF translocation was not significant. 3. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the $Ca^{2+}$-free buffer was shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the $Ca^{2+}$-free buffer on mechanically induced ANP secretion(p < 0.05), but ECF translocation was not significant. The results suggest that PKC-induced ANP secretion may not be related to the change of $Ca^{2+}$ on mechanically induced ANP secretion in the rat atria.

주산기 랫드 모체에서 Insulin-like Growth Factor System의 변동

진송군,박수현,조남표,강창원,Jin, Song-jun,Park, Soo-hyun,Cho, Nam-pyo,Kang, Chang-won 대한수의학회 2003 대한수의학회지 Vol.43 No.3

Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are important regulators on the development of maternal tissues during pregnancy. This study was performed to examine the relationship between maternal IGFs/IGFBPs system (i.e: IGF-I, II, their receptors, and IGFBPs) in pre- and post-partum rats. The liver and kidney are important organs for the synthesis of IGFs and IGFBPs in adults. The levels of materanal IGFs and IGFBPs in serum, liver, and kidney were examined at 14 and 21 days of gestation and at 3, 7, 11, and 14 days after birth. The expression of IGFs and their receptors mRNA was also examined in fetal and maternal rat liver, kidney. IGF-I concentrations in maternal serum and liver were decreased during pregnancy. However, IGF-I concentration in maternal kidney was increased, having maximal effect at 14 days of gestation. IGF-I concentrations were decreased in serum, liver, and kidney of postpartum rat, compared to control (p < 0.05). On the other hand, IGF-II concentrations in serum, liver, and kidney were increased during pregnancy (p<0.05) and gradually decreased to control level in postpartum period. The levels of IGFBP-3 and IGFBP-2 are expressed in serum, liver, and kidney. However, IGFBP-3 is mainly expressed in serum and liver, and IGFBP-2 in kidney. The levels of IGFBP-3 and IGFBP-2 in maternal serum were markedly decreased during pregnancy and gradually recovered to control level during postpartum period by western ligand blotting. However, there was no change of IGFBP-3 and IGFBP-2 levels by western immunoblotting. The levels of IGFBP-3 and IGFBP-2 in maternal liver and kidney also showed the same pattern of serum, although the main IGFBP is different. In normal rat serum, IGF-I 150 kDa and 50 kDa carrier proteins were detected. The level of IGF-I 150 kDa carrier proteins in pregnant rat was decreased compared to normal rat, but that of 50 kDa carrier proteins was increased. IGFBP-3 protease activity was identified in pregnant rat serum and maternal placenta, and it was inhibited by EDTA ($Ca^{2+}$ chelating agent) and aprotinin (serine proteinase inhibitor). Taken together, these results suggest that the changes of IGFs and IGFBPs in maternal rats are regulated by liver and kidney IGFs and their receptors mRNA during the pregnancy.

Changes of insulin like growth factor-I, IGF-I carrier protein in streptozotocin-induced diabetic rat

허영란,김송군,김진상,강창원,Heo, Young-ran,Jin, Song-jun,Kim, Jin-shang,Kang, Chang-won The Korean Society of Veterinary Science 2000 대한수의학회지 Vol.40 No.3

This study was conducted to investigate the effects of streptozotocin-induced (STZ) diabetes on insulin-like growth factor-I (IGF-I), insulin-like growth factor binding proteins (IGFBPs), and IGF-I carrier proteins in serum, liver, and kidney. The levels of total and free IGF-I were measured by radioimmunoassay (RIA). The patterns of IGFBPs were determined by western ligand blotting (WLB) analysis. The profiles of IGF-I carrier proteins in serum were determined by column chromatography. The levels of total and free IGF-I in serum were lower in STZ-induced diabetic rat than normal rat (p<0.01). Similarly, the levels of total IGF-I in liver was lowered in STZ-induced diabetic rats. On the other hand, the levels of total IGF-I in kidney were increased in STZ-induced diabetic rats compared with normal rats (p<0.01). In serum and liver from STZ-induced diabetic rats, the amount of IGFBP-3 was decreased and the amount of IGFBP-2 was increased compared with normal rats. There was a not difference in amount of IGFBP-4 in serum between STZ-induced diabetic rats and normal rats. The serums of normal rats have higher 150kDa carrier proteins than in STZ-induced diabetic rats, whereas, most of 50kDa carrier proteins were found in STZ-induced diabetic rats. These results demonstrate that in STZ-induced diabetic rats, IGF-I/IGFBPs system that included functional bioactivity was changed in serum as well as tissues, and these changes may play an important role in pathogenesis of diabetes.

변압기절연유 누설전류와 변압기열화의 상관성 분석

강창원(Kang Chang-won),최길수(Choi gil-soo),홍성준(Hong seong-jun),전영갑(Chon young-kap),김재철(Kim jae-chul) 대한전기학회 2000 대한전기학회 학술대회 논문집 Vol.2000 No.7

사료원료의 품질과 평가

강창원 ( Chang Won Kang ) 한국영양사료학회 1993 사료가공 단기과정 Vol.- No.-