생쥐의 심장발생과정에서 세포증식과 세포고사의 역할

김어진,김효수,서정욱,김어진,김효수,서정욱 대한병리학회 1998 Journal of Pathology and Translational Medicine Vol.32 No.12

자연과 수업에서 Vee Diagram 의 적용에 대한 연구

정진우,송보용,김효남 한국교원대학교 과학교육연구소 1994 청람과학교육연구논총 Vol.4 No.1

The purpose of this study is to analize the effect of Vee Diagram on the ability of scientific investigation, scientific attitude, cognitive ability in elementary school. For this study, 68 sixth grade students were selected and they were divided into two group: one is the experimenal group with Vee diagram instruction, the other is the control group with conventional instruction. Data were collected from the samples to know effect of Vee Diagram instruction and compared the experimental group with the control group. The result of analysis is as follows: 1. The vee diagram instruction is better than the conventional instruction for improving the scientific inquiry skills. 2. The vee diagram instruction does not show statistically meaningful difference to the conventional instruction for improving the scientific attitude. 3. The vee diagram instruction is better than conventional instuction for improving scientific knowledge. The results indicated that Vee diagram instruction is effective in learning strategy for improving scientific attitude.

인공신경망 이론을 이용한 충주호의 수질예측

정효준,이소진,이홍근 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

This study was carried out to evaluate the artificial neural network algorithm for water quality forecasting in Chungju lake, north Chungcheong province. Multi-layer perceptron(MLP) was used to train artificial neural networks. MLP was composed of one input layer, two hidden layers and one output layer. Transfer functions of the hidden layer were sigmoid and linear function. The number of node in the hidden layer was decided by trial and error method. It showed that appropriate node number in the hidden layer is 10 for pH training, 15 for DO and BOD, respectively. Reliability index was used to verify for the forecasting power. Considering some outlying data, artificial neural network fitted well between actual water quality data and computed data by artificial neural networks.

인삼첨가 Long Life면의 조직감과 관능적 특성

정재홍,심창주,신영,권효진,이규희,오만진 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.5

인삼이 밀가루의 아밀로그래프에 의한 호화 성질과 파리노그래프에 의한 반죽 성질에 미치는 영향을 조사하였다. 인삼첨가 LL면의 조직감과 관능적 특성에 미치는 영향을 분석하기 위하여 밀가루에 대하여 인삼을 5.0∼10% 첨가하여 LL면을 제조한 뒤 면의 조직 특성 분석 및 조리시험을 하고 관능검사를 하였다. 인삼을 첨가하면 아밀로그래프의 호화개시 온도를 3.1℃ 지연시켰으며, 최고 점도를 40B.U 감소시켰다. 파리노그래프의 흡수율은 1.2% 증가하였으며, 반죽의 안정도는 인삼의 첨가로 2.0분 길게 측정되었다. Hunter L값은 인삼 첨가량이 증가할수록 낮아졌으며, Hunter a, b값은 반대로 측정되었다. 인삼첨가 LL면의 층밀림 압출력은 첨가량의 증가에 따라 높아져 10.0%의 첨가는 대조구 18.65(㎏f)보다 2.3(㎏f) 높은 23.95(㎏f)로 측정되었으며, 경도도 대조구보다 5.4(㎏f) 높게 측정되었다. 인삼첨가 LL면의 무게 증가는 인삼의 첨가량이 증가할 때 다소 높게 나타났으나. 부피 증가는 오히려 높게 나타나 조직이 다소 치밀한 것으로 나타났다 용출량은 인삼량의 증가에 따라 약간 감소하였다. 미생물은 인삼의 첨가량이 증가할수록 줄어들어서 장기 저장이 가능하였다. 관능 검사 결과는 인삼첨가 LL면이 4.2 및 4.0으로 비교적 좋은 점수를 얻었다. 이같이 LL면 제조시 인삼 첨가량은 7.0%의 수준이 효과가 컸다. The influence of ginseng on the paste or gelatinization properties by amylograph and mixing properties by farinograph of wheat flour, and on quality properties, color, cooking quality, textural and sensory properties, and reducing microbial population of LL (Long Life) noodles was studied. The contents of ginseng used were from 5% to 10% based on flour weight. The viscosity property of wheat flour with ginseng was increased the initial pasting temperature but the amylograph peak viscosity were decreased in vice versa. The farinograph absorption, stability and breakdown were increased by ginseng. The whiteness of LL noodles manufactured with ginseng was lower than that of control. The shear extrusion force and hardness of LL noodles manufactured with ginseng were shown much higher value than those of control. At cooking quality examination of LL noodles manufactured with ginseng, weight of cooked LL noodles was decreased but volume was appeared in vice versa. Extraction amounts of LL noodles manufactured with ginseng during cooking were much smaller than those of control. Total counts of microorganism of LL noodles manufactured with ginseng were decreased during storage at 30℃. Sensory properties of cooked LL noodles which was manufactured with ginseng showed quite acceptable. Based on the cooking and sensory evaluation test, addition of 7.0% ginseng to wheat flour may be suitable for processing LL noodles.

폴리페닐렌옥사이드/에폭시 수지 블렌드의 경화거동 및 파괴인성에서 폴리페닐렌옥사이드가 미치는 영향

박수진,정효진,나창운 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

본 실험에서는 4관능성 에폭시 수지(4EP)와 Poly (phenylene oxide) (PPO) 블렌드의 경화거동, 열 안정성 그리고 기계적 계면특성을 알아보았다. PPO의 조성비는 0, 5, 10, 15, 20 phr로 하였다. 4EP/PPO 블렌드물의 경화거동은 근적외선 분광법과 시차주사열량계를 통해 관찰하였고, 열 안정성은 열분해 개시온도(IDT), 열안정성 인자 그리고 적분 열분해 진행온도(IPDT)에 의해 관찰하였다. 시편의 기계적 계면특성을 고찰하기 위해서 파괴인성 실험을 수행하였고, 시편의 파괴단면을 주사전자현미경으로 분석하였다. 그 실험결과, 전화율은 5 phr에서 높은 값을 나타내었고, 경화 활성화 에너지(E_(a))는 5 phr에서 PPO에 의해 경화가 가속화되어 감소되는 경향을 나타내었다. 열안정성은 분자내 PPO의 페닐그룹의 존재로 인해 PPO의 함량이 증가함에 따라 증가하였다. 또한 파괴인성 인자(K_(IC), G_(IC))는 5 phr에서 고분자 사슬 분자사이의 계면 결합력의 향상으로 인해 가장 높은 값을 나타내었다. In this work, the effect of poly (phenylene oxide) (PPO) in tetrafunctional epoxy resin (4EP) was investigated in terms of cure kinetics, thermal properties, and mechanical interfacial properties of the blends. The content of PPO was varied within 0, 5, 10. 15, and 20 phr to neat 4EP. The cure kinetics of 4EP/PPO blend system are examined by near-IR and DSC measurements. And the thermal stabilities were determined by initial decomposed temperature (IDT), thermal stability factors, and integral procedural decomposition temperature (IPDT) of the blends. For the mechanical interfacial properties of the casting specimens, the fracture toughness test was performed, and their fractured surfaces were examined by SEM. As a result, the conversion (a) is indicated in high value at 5 phr of PPO and, the cure activation energy (E_(a)) is decreased at 5 phr PPO, due to the plasticized PPO polymer molecule in epoxy resins. The thermal stabilities were increased, which can be explained by the presence of phenyl group of PPO in intermolecular chains. Also the fracture toughness parameters (K_(IC), G_(IC)) show high values at 5 phr PPO. This result is interpreted in the development of interfacial adhesion force between intermolecules of the polymer chains.

초·중·고 학생들의 과학 정의적 특성 추이 분석을 위한 종단적 연구

김효남,정완호,정진우,양일호,김영신 한국교원대학교 과학교육연구소 1999 청람과학교육연구논총 Vol.9 No.1

이 연구는 우리 나라 학생들의 과학의 정의적 특성의 성취 수준을 종단적으로 분석하여 국가 수준에서 과학교육 성과를 가늠해 봄으로써, 과학교육의 질을 향상시킬 수 있는 과학교육 정책의 기초자료를 제공하는데 그 목적이 있다. 이를 위하여 1997년 2월에 초중고학생 3603명, 1999년 3월에 초중고학생 4737명을 대상으로 과학의 정의적 특성을 조사하였다. 본 연구의 결과는 학교급별 과학의 정의적 특성의 성취 수준이 초등학교에서 중학교까지 통계적으로 유의미하게(p<.05) 하락 한 후 고등학교에서 상승하는 것으로 나타났다. 또한, 남학생이 여학생보다 통계적으로 유의미하게 높게 나타났다(p<.05). 남녀간의 성취수준의 차이는 학년이 올라갈수록 감소하는 것으로 나타났다. 지역별로는 소도시보다 대도시가 높게 나타났으며, 시간이 지날수록 그 차이가 커지는 것으로 나타났다. 1997년과 1999년의 성취 수준을 비교해보면 1999년의 성취수준이 통계적으로 유의미하게 낮게 나타났다. 또한, 국가수준의 과학에 대한 성취도를 분석할 수 있는 모니터 과정이 계속적으로 이루어지길 기대한다. The purpose of this study was to longitudinally analyze Korean students' trend on science-related affective characteristics and provide descriptive data for improving the quality of Korean science education. In this longitudinal study, 3603 students and 4737 students were sampled in elementary and secondary schools, respectively in January 1997 and March 1998. The result showed that students' affective characteristics were decreased with statistical significance(p<0.05) during elementary and junior high school periods, but students' affective characteristics were increased during high school period. Affective characteristics of male were significantly higher than those of females' (p<0.05). Difference on affective characteristics between female and male students was being decreased by increasing grades. Students' affective characteristics in metropolitan areas were significantly higher than those in regional areas and difference between them was increased in 1999 comparing to 1997. The students' affective characteristics in 1999 were lower than those in 1997 totally.

대장암 주변에서 관찰되는 백색반점의 병리조직학적 특성과 임상적 의의

김효종,조진만,장린,동석호,김윤화,장영운,박일랑,김병호,이정일 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.4

Background/Aims: To investigate the difference between colorectal adenocarcinomas with white spots (foamy cells) and those without white spots, clinically and histopathologically, were examined 37 cases of colorectal adenocarcinomas were classified in this study. Methods: Two groups: those with white spots and those without. In each case, evidence of lymph node and liver metastasis was sought. Immunoreactive staining for macrophage was performed. Results: Increased incidence of exophytic tumors was found (73%, p=0.028) in the group with white spots. The incidences of lymph node metastasis were 33% vs. 45% between the group with white spots and the group of without, but the difference was not statistically significant. Conclusions: These results suggested that foamy cells might have a beneficial role in colorectal cancer, although they were not statistically significant. Therefore, further prospective study be warranted.

Inhibitory Effect of Cordycepin on Human Platelet Aggregation

박화진,--,--,--,--,--,-- THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 2004 Journal of biomedical laboratory sciences Vol.10 No.1

Cordycepin separated from Cordyceps militaris is a major physiologic active component in Cordyceps militaris. The platelet aggregation is stimulated by Ca^(2+), which is either mobilized from intracellular endoplasmic reticulum or transported from extracellular space. cGMP antagonizes the actions of Ca^(2+). Based on these facts, we have investigated the effects of cordycepin on the mobilization of Ca^(2+) and the production of cGMP on collagen (10 ㎍/ml)-induced human platelet aggregation. Cordycepin potently stimulated the human platelet aggregation induced by collagen (10 ㎍/ml) in a dose-dependent manner. Cordycepin (500 μM) inhibited also the collagen-induced human platelet aggregation in the presence both 1 mM and 2 mM of CaCl_(2). These are in accord with the results that cordycepin inhibited the Ca^(2+)-influx on collagen-induced human platelet aggregation. These results suggest that cordycepin decrease the intracellular Ca^(2+) concentration to inhibit collagen-induced human platelet aggregation. Besides, cordycepin increased the level of cGMP on collagen-induced human platelet aggregation. This result is related with the decrease of intracellular Ca^(2+) concentration, because cGMP inhibits the mobilization of Ca^(2+). In addition, cordycepin inhibited the human platelet aggregation induced by LY-83583, inhibitor of guanylate cyclase. This result suggested that cordycepin inhibit the platelet aggregation by stimulating the activity of guanylate cyclase. In conclusion, we demonstrated that cordycepin might have the antiplatelet function by inhibiting Ca^(2+)-mobilization via the stimulation of the production of cGMP.

혼합 치열기 어린이의 치은 섬유종증

한효정,최병재,김진,김성오,손홍규 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.4

치은 섬유종증은 유리 치은과 부착 치은이 점진적으로 증식되는 비염증성 질환이다. 대부분 가족력이 있으며 영구치 맹출과 함께 발병하지만 유치 맹출 시기에, 드물게 출생 시부터 나타나기도 한다. 본 6세 여아의 경우 태어날 때부터 치은의 일부가 증식되어 있었고 가족력 및 치은 증식을 유발하는 약물을 복용한 병력은 없었다. 구강 내 검진 시 섬유성 치은 증식이 관찰되어 절제 생검을 시행하였고 그 결과 치은 섬유종증으로 진단하였다. 치은 섬유종증의 치료는 치은 절제술과 철저한 구강 위생의 관리이다. 그러나 치료 후 재발성 때문에 치료 시기에 대해서는 논란 중이다. 일반적으로 영구치가 모두 맹출 한 이후에 치료할 것을 추천하지만 조기 치료는 구강의 기능 및 환아의 심미적, 심리적인 문제점을 개선시켜 주는 장점이 있다. Gingival fibromatosis is a non-inflammatory oral disease, characterized by slowly progress enlargement of the free and attached gingiva. Gingival fibromatosis may have familial tendency. Gingival enlargement usually begins with the eruption of the permanent dentition but can also develop with the eruption of the primary dentition. In this case, a 6-year-old female had gingival enlargement at birth. There was no familial, medical and pharmacologic history of gingival overgrowth. Treatment is gingivectomy with a rigorous program of oral hygiene. Recurrence of gingival fibromatosis may well be inevitable. Therefore there is no general aggrement as to the timing of surgical intervention. Generally the best time is when all the permanent teeth have erupted. However early intervention can improve oral function and esthetic and psychologic effect.

HMG-CoA 환원효소 억제제에 의한 ICAM-1 유전자의 발현조절

김현진,정효균,홍우정,김군순,조영석,김도희,채수흥,구본정,송민호,노흥규,김영건 충남대학교 의과대학 지역사회의학연구소 2001 충남의대잡지 Vol.28 No.1

Background : ICAM-1 act as one of major adhesion molecules in the atherosclerotic lesion. ICAM-1 expression is mainly regulated at the level of transcription and depend on IFN-γ signal transduction pathway in which the STAT1 transcrption factor is a critical intermediate. IFN-γreceptor not only initiates tyrosine 701 phosphorylation of STAT1 by Jak1 and Jak2, but also phosphorylates serine 727 through the activation of Raf-1/MAP kinases. HMG-CoA reductase inhibitors have anti-atherosclertic effects, beyond normalization of hypercholesterolemia, by directly acting on endothelial cells, macrophages and vascular smooth muscle cells. HMG-CoA reductase inhibitors suppress the synthesis of isoprenoid intermediates such as geranylgeranyl-pyrophosphate or farnesylpyrophosphate. These effects results inhibitors suppress the synthesis of isoprenoid intermediates such as geranylgeranyl-pyrophosphate or farnesylpyrophosphate. These effects results inhibition posttranslational farnesylation and geranyl-geranylation processing of small GTP-binding preoteins and inhibition of normal signaling activities. Method : We made several 5'-deletion constructs of rat ICAM-1 promoter and analyzed the promoter activities by measuring the luciferase activity after transfection into ECV304 cells and smooth muscle cells. We checked the level of total and phosphorylated STAT1 protein by immunoblot analysis using specific antibodies. Results : Lovastatin inhibits IFN-γ-induced ICAM-1 gene expression in the ECV304cell. The cells pretreated with PD98059, MEKK inhibitor showed significantly low ICAM-1 RNA induction with IFN-γ stimulatio. IFN-γ induced phosphorylation of tyrosine 701 was not significantly changed by the pretreatment of lovastatin. But lovastatin suppresses IFN-γ-induced phosphorylation of ERK1/ERK2 which are responsible for the seine 727 phosphorylation in STAT1. Conclusion : We showed that HMG-CoA reductase inhibitors, lovastatin, suppresses IFN-γ mediated ICAM-1 gene expression through the inhibition of transcription. HMG-CoA reductase inhibitor suppresses IFN-γ-induced phosphorylation of serine 727 in STAT1 through the modulation of MAP kinases.