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 大韓獸醫學會誌 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.

특별기고 - 생존을 넘어 성장을 위한 기본전략

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

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

우리나라에서는 3 Θ 4w 배전방식을 채택하고 있는데 최근에는 컴퓨터 등 OA 기기 사용증가로 이때 발생하는 영상분 고조파에 의하여 중성선에 상전류 보다 큰 전류가 흐르게 된다. 고조파에 의한 중전선 과전류는 케이블, 변압기, 과열소손, 변압기, 발전기 출력저하, 역률저하, 전력손실 증가, ELB, MCCB 오동작, 유도장해, 중성선 대지전위 상승 등 심각한 장애를 일으키고 있다. 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.

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 大韓獸醫學會誌 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.

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 大韓獸醫學會誌 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.

심방이뇨호르몬의 분비조절에 있어서 superoxide anion의 영향

강창원,김남수,이호일,Kang, Chang-won,Kim, Nam-soo,Lee, Ho-il 대한수의학회 1996 大韓獸醫學會誌 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.

투자자의 IFRS에 대한 인식과 투자성향이 기업이미지와 투자의향에 미치는 영향

강창원(Kang, Chang Won) 한국국제회계학회 2013 국제회계연구 Vol.0 No.48

본 연구에서는 최근 세계적으로 도입 추세에 있는 IFRS의 도입 효과에 대한 실증적 연구를 통하여 기업 가치에 미치는 영향을 규명하고, 기업 가치 제고를 위한 전략적 시사점을 제공하고자 하였다. 수도권을 중심으로 투자자 269명에 대한 설문분석 결과, 첫째, IFRS 도입으로 인한 회계정보의 질이 기업의 장래성과 재무건전성에 대한 이미지에 긍정적 영향을 미치는 것으로 밝혀졌다. 둘째, 투자자의 투자성향에 관계없이 IFRS 도입이 기업이미지에 긍정적인 영향을 미치는 것으로 밝혀졌으며, 공격적 투자성향은 장래성에, 안정적 투자성향은 재무성의 영향력이 더 큰 것으로 밝혀졌다. 셋째, IFRS를 도입한 기업의 재무성에 대한 이미지는 투자결정에 긍정적인 영향을, 장래성은 영향을 미치지 못하는 것으로 분석되었다. 이와 같은 결과는 투자자는 IFRS의 도입으로 회계정보의 질이 향상될 것이라 인식하고 있고, IFRS 도입이 기업 이미지에 긍정적인 영향을 미치며, 결과적으로 투자 의사결정에도 영향을 미치는 것으로 밝혀졌다. 또한 투자성향에 따라 투자의사결정에 영향을 미치는 요인의 중요성이 다르다는 것도 확인할 수 있었다. 이러한 결과에 따라서 IFRS를 이미 도입한 기업은 기업 가치를 한 단계 높일 수 있는 기회로 활용해야하며, IFRS 도입을 준비하는 기업에서는 전략적인 차원에서 도입을 위한 준비와 기업가치 제고를 위한 노력도 병행해야 할 것이다. This study was aimed to provide companies to strategic implications to affect and promote corporate value through IFRS adoption which is in global trend. The questionnaire study of 269 investors who have lived in Seoul metropolitan was conducted to know their valuation and investment decisions. The results of this study as follows. First, the qualitative enhancement of accounting information by IFRS adoption had a positive effective on sustainability and financial soundness of firms. Second, IFRS adoption had a positive effect on corporate images regardless of investors dispositions, which active investors is more favor to sustainability and stable, financial soundness respectively. Third, IFRS adoption hardly affected the sustainability of firms, but had a positive effect on the financial soundness. In conclusion, IFRS adoption makes investors perceive the qualitative enhancement of accounting information and has a positive effective on corporate images and as a result it affects investment decisions. Besides, the importance of main decision factors was shown differently according to investor dispositions. Consequently, companies which already adopted IFRS should take advantage of it to leap corporate value and firms preparing for it should make an effort to strategic adoption of IFRS in order to enhance their value.

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 大韓獸醫學會誌 Vol.40 No.3

본 연구에서는 Streptozotocin-induced 당뇨가 혈청과 간장 및 신장조직의 IGF-I, IGFBPs 및 IGF-I carrier protein 특성에 미치는 영향을 조사하였다. 혈액과 조직중의 IGF-I 농도는 방사면역측정법으로 측정하였고, IGFBPs 양상은 Western Ligand Blotting(WLB)으로 관찰하였으며, IGF-I carrier protein의 특성은 column chromatography로 측정하였다. 혈청과 IGF-I 농도는 당뇨군이 대조군에 비하여 유의하게 감소하였다 (p<0.01). 당뇨군은 대조군에 비하여 간장 IGF-I 농도는 유의하게 감소한 반면, 신장의 IGF-I 농도는 유의하게 증가하였다(p<0.01). 당뇨군은 대조군에 비하여 혈청과 간장의 IGFBP-3는 감소한 반면, IGFBP-2는 증가하였고, IGFBP-4는 변화가 없었다. 또한 당뇨군은 대조군에 비하여 150kDa carrier protein은 감소하였으며, 50kDa carrier protein은 증가하였다. 이상의 결과를 종합해볼 때 Streptozotocin-induced 당뇨는 혈청 뿐만 아니라 조직의 IGF-I/IGFBP system 변동에 영향을 미침을 알 수 있었다. 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.

사료원료의 품질과 평가

강창원 ( Chang Won Kang ) 한국영양사료학회 1993 제5회 사료가공 단기과정 Vol.- No.-

계장용 볼 밸브 유량계수 Cv 측정에 관한 연구

강창원(Chang-Won Kang),이중섭(Chung-Seob Yi),장세민(Se-Min Jang),이치우(Chi-Woo Lee) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.3

The results of the measurement of the flow-rate coefficient (Cv-value) and the analysis of a small ball valve are summarized follows. The Cv-values of 1/2-, 3/4- and 1-inch ball valves were measured using a flow-rate measurement test. The manufacturer obtained the Cv-value using a theoretical calculation method. The new experimental measurement and analysis method yielded more reliable results. In addition, the Cv value obtained through numerical analysis was almost identical the value provided by the manufacturer, which was based on experimental results. A Study on Flow Analysis results are all similar appearances as the reliability of the results.