함께하는 과학기술, 다가오는 선진한국

이종화,Lee, Jong-Hwa 한국과학기술단체총연합회 2005 과학과 기술 Vol.38 No.5

Calcium Movement in Carbachol-stimulated Cell-line

이종화,Lee, Jong-Hwa The Korean Society of Pharmacology 1995 대한약리학잡지 Vol.31 No.3

Calcium수송에 대한 기전을 추구하기위하여, carbachol을 사용하여 ml muscarinic receptor-transfected RBL-2H3 cell-line에서 다음과 같은 실험결과를 얻었기에 이에 보고한다. 1) Carbachol의 투여로 이들 cell-line에서 $Ca^{2+}$ influx가 농도에 따라 증가하였고, hexosaminidase 분비양도 의의있게 증가하였다. 2) Atropine 투여로 Carbachol의 상승작용이 의의있게 억제되었다. 3) 수종의 금속양이온을 투여하여 carbachol의 $Ca^{2+}$수송에 대한 영향을 관찰한 바, 이들 금속이온들은 $Ca^{2+}$의 influx를 의의있게 억제하였다. 4) PMA(20 nM) 투여로 carbachol의 hexosaminidase의 분비는 억제되지 못했지만 $Ca^{2+}$ influx는 억제되었다. 5) PTx $(0.2\;{\mu}g/ml)$ 투여로 carbachol의 hexosaminidase 분비가 의의있게 억제되었다. 위의 결과로 미루어 보아, 이 세포의 muscarinic receptor가 calcium channel을 통한 calcium수송에 매우 중요한 영향을 나타내는데, 이들 calcium ion channel은 적어도 두 종류가 존재하며, 하나는G-protein-dependent calcium channel에 의하며, 다른 하나는 G-protein-independent calcium channel에 대한 작용에 의한 것으로 생각된다. 또한 이 calcium channel들은 2가 또는 3가의 다른 금속 ion들에 의하여 calcium수송이 억제된다. It has been well known that the intracellular calcium concentration $([Ca^{2+}]_i)$ in living cell is very sensitive to live or to survive, but the transmembrane system of calcium ion, especially mechanism of calcium ion movement in unexcitable state has been little elucidated. Though many proposed theories for calcium ion transport have been reported, it is still unclear that how could the sustained maintenance in cytosolic calcium level be done in cell. Since one of possible mechanisms of calcium transport may be related to the acetylcholine receptor-linked calcium channel, author performed experiment to elucidate this mechanism of calcium influx related to cholinergic receptor in ml muscarinic receptor-transfected RBL-2H3 cell-line. 1) The effects of carbachol both on calcium ion influx and on the secretion of hexosaminidase were respectively observed in the manner of time-related or concentration-dependent pattern in this model. 2) The effects of several metal cations on calcium transport were shown in carbachol-induced cell-line. 3) Atropine was administered to examine the relationship between cholinergic receptor and calcium ion influx in this model. 4) PMA (Phorbol 12-myristate 13-acetate) or PTx (Pertussis toxin) was respectively administered to examine the secondary mediator which involved pathway of calcium ion movement in carbachol-induced cell-line. The results of this experiments were as follows; 1) Carbachol significantly stimulated both the calcium influx and the secretion of hexosaminidase in the manner of the concentration-dependent pattern. 2) Atropine potently blocked the effects of carbachol in concentration-response manner. 3) Administered metal cations inhibited the calcium influx in carbachol-stimulated this model to the concentration-related pattern. 4) PMA did not inhibit carbachol-induced secretion of hexosaminidase, but blocked the calcium influx in this cell-line. 5) The suppression of carbachol-induced hexosaminidase secretion was shown in PTx-treated cell -line.

차폐층을 갖는 다층고온초전도 전력케이블의 전류분류 분석

이종화,임성훈,임성우,두호익,한병성,Lee Jong-Hwa,Lim Sung-Hun,Yim Seong-Woo,Du Ho-Ik,Han Byoung-Sung 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.3

High-$T_c$ superconducting (HTSC) power cable is one of the interesting parts in power application using HTSC wire. However, its stacked structure makes the current distribution between conducting layers non-uniform due to difference between self inductances of conducting layers and mutual inductances between two conducting layers, which results in lower current transmission capacity of HTSC power cable. In this paper, the transport current distribution between conducting layers was investigated through the numerical analysis for the equivalent circuit of HTSC power cable with a shield layer, and compared with the case of without a shield layer. The transport current distribution due to the increase of the contact resistance in each layer was improved. However, its magnetization loss increased as the contact resistance increased. It was confirmed from the analysis that the shield layer was contributed to the improvement of the current distribution between conducting layers if the winding direction and the pitch length were properly chosen.

웹기반 초등학교 과학과 발견학습 시스템

이종화,한규정,Lee, Jong-Hwa,Han, Kyu-Jung 한국정보교육학회 2008 정보교육학회논문지 Vol.12 No.1

제 7차 초등학교 과학과 교육과정에서는 특히 탐구학습을 강조하고 있다. 그러나 단위 시간과 학습자료의 부족이라는 현실적인 이유 때문에 학교 교육 현장에서는 실제적인 적용이 어렵다. 본 연구에서는 이러한 문제점을 해결하기 위하여 웹기반 발견학습 시스템을 설계 구현하고 그 효과성을 검증하는데 목적이 있다. 검증 과정으로 초등학교 4학년 과학과의 용수철 늘이기 단원을 대상으로 일반적인 발견학습 모형을 적용한 비교집단과 웹기반 발견학습 시스템으로 수업을 받은 실험집단의 학업성취도에 있어 유의미한 차이가 있는지 조사하였다. 적용 결과, 웹기반 발견학습 시스템으로 수업을 한 경우, 전통적인 발견학습 모형 그대로 적용한 경우보다 학업 성취도가 높았다.

高解像度 TV 信號의 프레임-오프셋 副標本化에서의 새로운 動領域 檢出 方法

이종화,정해묵,이충웅,Lee, Jong-Hwa,Jung, Hae-Mook,Lee, Choong-Woong 대한전자공학회 1990 전자공학회논문지 Vol. No.

본 연구에서는 高解像案 TV 信號의 QT 構造 副標本化에 의한 帶域壓縮 方式에서 受信側의 復元획質을 개선하기 위해 OS 濾波器를 이용한 새로운 動領域檢出 方法을 提示하였으며, 이 방법을 이용하여 HDTV의 帶域壓縮 方式으로 이미 提案된 바 있는 MUSE 방식을 개선할 수 있음을 물론, 프레임-오프셋 副標本化를 이용한 각종 高解像案 TV信號의 帶域壓縮 방식에 적용할 수 있음을 보였다. In this paper, a new motion detection method using an order-statistic filter is proposed to improve the image quality when the QT subsampling structure is used for reduction of bandwidth of high-resolution TV signals. This new method is applicable to the MUSE system of HDTV and various schemes using the multiple subasmpling with frame-offset for the reduction of bandwidth in highresolution TV signals.

토복령알코홀추출물이 토끼 적출 십이지장관운동에 미치는 영향

이종화,김정일,송민자,Lee, Jong-Hwa,Kim, Chung-Il,Song, Min-Ja 대한약리학회 1973 대한약리학잡지 Vol.9 No.2

Chinae Rhizoma is dried crude roots and rhizomes obtained from Smilax china Linne which belongs to Smilax Genus of Liliaceae Familia, and it has been in wife use as a folk remedy for a long time. But very little systemic studies on its pharmacological actions have been made until now. Furthermore, the effective components except saponin of Chinae Rhizoma have been not known yet. It came to the attention of the authors that Chinae Rhizoma are used as antidiarrhetics in Chinese herb medicine, therefore they attempted to observe the effects of Chinae Rhizoma Alcoholic Extracts (Chinae Rhizoma Ethanol Extract=CREE, Chinae Rhizoma Methanol Extract=CRME) from Smilax china Linne on motility of the isolated rabbit duodenum in this experiment. The results of the study were as follow: 1. The movement of the isolated rabbit duodenum was slowed down and its tonus was relaxed in proportion to the concentration of Chinae Rhizoma Alcoholic Extracts (CREE & CRME). 2. With a concentration of CREE $10^{-4}g/ml$, the contractile effects of acetylcholine $10^{-6}g/ml$, pilocarpine $10^{-5}g/ml$ and physostigmine $10^{-5}g/ml$ were remarkably blocked in the movement of isolated rabbit duodenum. 3. The concentration of the isolated rabbit duodenum induced by barium chloride $10^{-4}g/ml$ was significantly inhibited by CREE $10^{-4}g/ml$. 4. With the administrations of histamine $10^{-5}g/ml$, serotonin $10^{-6}g/ml$ and prostaglandin $A_2\;10^{-6}g/ml$ respectively, contractions were observed in the rabbit duodenum. But, treatment of CREE $10^{-4}g/ml$ inhibited markedly the tonus and motility of the duodenum pretreated with the above drugs. 5. The effects of CREE and CRME were very much alike in this experiment. From the above results, it is concluded that the mechanism of action of Chinae Rhizoma on motility of isolated rabbit duodenum was partially due to cholinergic blocking effect.

Agonist-Antagonist Effects of Buprenorphine on Action Potentials of Frog Sciatic Nerve Fibers

이종화,Lee, Jong-Hwa,Frank, George B. The Korean Society of Pharmacology 1989 대한약리학잡지 Vol.25 No.1

함께 투여되는 마약성진통제에 따라 효능제 또는 길항제(mixed agonist-antagonist)로 작용하는 buprenorphine을 사용하여 개구리 좌골신경에 존재하는 아편수용체의 성질을 검토하였다. 실험은 sucrose-gap apparatus를 사용하여 활동전압에 대한 영향을 관찰하였으며 약물의 상호작용을 검토하고자 meperidine 또는 naloxone을 사용하여 다음과 같은 결과를 얻었다. 1) Buprenorphine은 현저하게 개구리 좌골신경의 활동전압을 저하시켰다. 2) 두 개의 최고작용농도를 보였는데 저농도에서는 $10^{-8}\;M$, 또 고농도에서는 $10^{-4}\;M$에서 현저하게 작용을 나타내었다. 3) Buprenorphine은 meperidine의 활동전압 저하작용을 의의있게 억제하였다. 4) Naloxone에 의하여 Buprenorphine의 저하 작용이 억제되었다. 위의 실험결과로 Buprenorphine은 순수 마약성진통제의 작용을 억제하여 차단제로 작용하는 한편 또한 효능제로 활동전압을 의의있게 억제하였다. 이로써 개구리 좌골신경에 있는 아편수용체는 세포막에 또는 세포막 주위에서 $Na^+-Channel$이 활성화되는 데 중요한 역할을 하는 것으로 간주되며 이 수용체는 또한 Naloxone에 매우 민감한 반응을 나타낸다. Buprenorphine, one of the mixed agonist-antagonist opioid drugs was used to inverstigate the opioid receptor on frog sciatic nerve A fibers. Action potentials were recorded for 4 hrs by a sucrose gap apparatus which were separated by four rubber membranes. To examine the one of the mechanism of action of buprenorphine, meperidine or naloxone was added after or before the treatment of buprenorphine. The results of this experiment were as follows: 1. Buprenorphine suppressed significantly the compound action potentials of frog sciatic nerve, and the maximal effects were shown both at $10^{-4}\;M$ and at $10^{-8}\;M$. 2. The dose-response relationship of buprenorphine on the depressant effect in frog sciatic nerve was biphasic and inverted U-shaped. 3. Buprenorphine blocked the effect of Meperidine $(10^{-3}\;M)$ on this preparation. 4. The depressant effcct of Buprenorphine on frog sciatic nerve was blocked by $10^{-8}\;M$ naloxone. From the above results, buprenorphine acts as one of agoinist-antagonistic effect on frog sciatic nerve, and the opioid receptor on this preparation is located on or near the intracellular opening of the sodium channels, which are sensitive to naloxone.

방재시험소를 둘러보고 - 시험소 발전에 업계의 관심과 지원 뒤따라야

이종화,Lee, Jong-Hwa 한국화재보험협회 1987 防災와 保險 Vol.32 No.-

과학기술 관련기관 '88새해설계-한국인삼연초연구소

이종화,Lee, Jong-Hwa 한국과학기술단체총연합회 1988 과학과 기술 Vol.21 No.1

조직은 인재가 아닌 인재가 필요하다

이종화,Lee, Jong-Hwa 한국건설안전협회 1995 建設 安全技術 Vol.15 No.-