백서의 우울모형에서의 칼슘통로 길항제 에타베린(Ethaverine)의 항우울효과

이상경,김선희,김록우,윤성환,김용관,김경태,김영훈 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 본 전임상연구에서는 우울증의 두가지 동물모형을 통해 에타베린이 단독 혹은 이미프라민과 병용처치 되었을 때의 효과를 알아보고자 하였다. 방법: 표준화된 검사법인 강제수영검사를 사용하여 옹성백서에게 에타베린(20mg/kg) 및 이미프라민 (20mg/kg)을 단독 혹은 병용 처치하였을 때의 부동시간의 변화를 관찰하였고, 경도의 만성 스트레스를 3주간 가한 후 4주간 에타베린과 이미프라민을 단독 혹은 병용 처치하였을때의 자당섭취량의 변화를 관찰하였다. 결과: 약물을 1회 단기처치 및 7일간 장기처치한 강제수영검사에서 이미프라민 및 에타베린 단독처치는 대조군에 비하여 부동시간의 단축을 보였고 에타베린은 이미프라민의 부동시간 감소에 대한 증강작용을보였다. 경도의 만성스트레스 실험에서도 3주간의 스트레스로 인하여 감소된 백서의 자당섭취량을 이미 프라민 및 에타베린이 회복시켰으며, 치료초기에 두 약물의 병용처치효과가 두드러졌다. 결론: 본 연구의 결과는 에타베린이 향우울 효과를 가지고 있음을 시사하며, 삼환계 항우울제인 이미프라민의 항우울효과를 증강시키므로 에타베린의 임상적 활용 가능성을 보여준다. Objectives: This pre-clinical study was performed to assess the effects of ethaverine in the two kinds of behavioral models of depression in rats. Methods: We observed the changes of the immobility time in the froced swimming test and the quantity of sucrose consumed in the chronic mild stress model, using ethaverine(20mg/kg) alone, imipramine(20mg/kg) alone, or ethaverine and imipramine concomitantly. Results: In the forced swimming test, both single treatment and chronic treatment(for 7days) with imipramine or ethaverine significantly reduced the immobility time, and concomitant chronic treatment with ethaverine potentiated the effect of imipramine. In the chronic mild stress model, both imipramine and ethaverine reversed the decreased sucrose consumption induced by 3-week stress and concomitantly treated ethaverine potentiated the effect of imi-pramine in the early phase of treatment. Conclusions: The data suggest that ethaverine can be used alone or concomitantly with other antidepressants in the clinical situation.

Teachers' Voices on Elementary English Education and Policy, and Its New Directions

Kim,Yang-Hee,Jong,Young-Kyong 한국초등영어교육학회 2009 초등영어교육 Vol.15 No.2

This study investigated how elementary English teachers who attended in a graduate school perceived elementary English education in Korea, what concern they faced, and what suggestions they had to help create better and more effective English teaching and learning environment. To answer these research questions, data was collected by reflection papers(about the general ideas and thoughts of how they perceived elementary English education), open-ended survey, and interviews. This study found four main themes(findings): 1) needs for sufficient language exposure; 2) management skills in teaching; 3) teacher qualifications and 4) needs for well-designed professional training program for teachers. These themes tell that children in the classroom needed to receive language input as much as they could and to have an opportunity to speak. To create better teaching and learning systems, the schools needed qualified teachers who can deliver good knowledge of English and are equipped with expertise in teaching. Well-designed training programs should be provided to these teachers to improve their professional development in teaching. This study showed a good understanding of current situations in terms of elementary English education through the teachers' voices, and it also provided new directions for English education.

최대 칩두께를 이용한 쏘블레이드에서 칩핑과정의 역학적 모델링

김경우,김우순,최현민,김동현 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

In order to establish the optimum process parameters and diamond saw blade composition for machining natural stone, the chip formation process and the wear process must be understood. Diamond saw blade is one of the most effective, versatile, and extensively used methods of processing rock and other hard materials, such as granite, marble, concrete and asphalt. For many years, it has been known that chip thickness is one of the most significant in the understanding of the sawing process, and other variables such as force and power have been correlated with it. In this study, mathematical relations of a material chipped by a single grit of the saw blade will be undertaken. The material chipping geometries have been mathematically defined and derived as maximum chip thickness.

폐주불사를 혼입한 콘크리트의 내구성에 관한 연구

김태경,박정호,이정호,이주형,박제선,김연경,윤경구 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

콘크리트 구조물은 자연적인 혹은 인위적인 온도의 상승, 강하로 인하여 동결-융해 작용을 받게 되어 구조물의 성능저하를 야기시킨다. 현대에 들어서면서 콘크리트의 내구특성을 파악하기 위한 연구적 요구가 증가되고 있다. 따라서 폐주물사 콘크리트를 실제 구조물에 적용하기 위해서는 내구특성에 대한 연구가 반드시 이루어져야 한다. 폐주물사를 혼입한 콘크리트의 내구특성을 파악하기 위한 동결-융해 실험은 폐주물사의 잔골재 치환율, 물-시멘트비, AE제 사용 여부를 주요 변수로 하여 실시하였다. 원형공시체를 제작하여, 동결-융해 시험기에 넣어 -18∼4℃로 급속 동결-융해를 진행시키면서 매 23싸이클마다 동탄성계수를 측정하였다. 실험결과 AE제를 첨가했을 때 물-시멘트비가 적을수록, 폐주물사의 치환율이 클수록 전반적으로 강도가 증가하는 것으로 나타났으며, 물-시멘트비가 증가함에 따라, AE제를 사용한 콘크리트가 동결-융해 저항성이 증가하는 것으로 나타났다. 특히 폐주물사 치환율이 50%일 때가 동결-융해 저항성이 가장 좋은 것으로 나타났으며 그 다음으로 25, 0% 순으로 저항성이 좋은 것으로 나타났다. 따라서 폐주물사 콘크리트가 내구성이 우수한 것으로 나타나 폐주물사를 콘크리트에 재활용 할 수 있는 것으로 나타났다. Concrete structures has been deteriorated by the freezing and thawing due to temperature gap. This study was conducted to evaluate durability of concrete which are increasingly demanded recently. Therefore the research of durability must be executed for application of waste foundry sand concrete real structures. Concrete durability properties incorporating waste foundry sand was performed with the variable of W/C ratio, Sand/Waste foundry sand ratio and Air entrainment-Non air entrainment. Cylinder specimens were made and subjected to freezing and thawing cycle at -18℃ and 4℃. Dynamic modulus of elasticity were evaluated as F/T cycle increase. The results show that strength of concrete is increased the W/C ratio decrease, the Sand/Waste foundry sand ratio increase when the concrete contains AE agent and decreasing W/C ratio and AE concrete makes improved resistance of freezing and thawing improved. Especially, resistance of freezing and thawing is improved by Fine aggregate/Waste foundry sand ratio which is 50%, 25%, 0% in a row. Therefore it is turn out the waste foundry sand could be applied to concrete from the experiment.

CU175NS 적층판 복합재의 절삭가공특성 연구

김동현,김우순,김경우 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.1

Carbon fiber epoxy composite are widely used in airframe structures, space vehicles, sports equipment, and high speed reciprocating parts fur industrial machinery. In this paper, the groove processing characteristics of carbon fiber epoxy composite was experimentally investigated in order to study the endmill operation of fiber reinforced epoxy composites. Followings are main finding from the experimental results. First, the cutting and bending force in groove processing of the carbon fiber epoxy composite increased as the spindle speed deceased. They also decreased as the table feed increased. Second, the good cutting status obtained at the entrance of groove while delamination occurred at the exit of groove. Third, the regular high speed steel endmill was not efficient. thus the new endmill such as coated carbide rooter endmill or diamond endmill should be used for the effective endmill operation of carbon fiber epoxy composites.

Rifampicin에 의한 것으로 추정되는 위막성 대장염1예

김수현,이은우,정종혁,문승현,김동한,양혁승,오영상,김호동,김도현,박혁,박정환,박경옥,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Pseudomembranous colitis, caused by altering the normal colonic flora and allowing the multiplication of Clostridium difficile, is an deleterious adverse effect of antibiotics. But it is rarely reported by rifampicin. Rifampicin is one of the first line drug in the treatment of tuberculosis and many patients are exposed to its potential adverse effects. We experienced a patient that had abdominal discomfort and hematochezia due to pseudomembranous colitis after receiving antituberculous medication, and which was probably caused by rifampicin. A 82 years old man was admitted with abdominal discomfort and hematochezia for one week. On the past history he had been diagnosed as endobronchial tuberculosis about 4 months ago. Colonoscopy revealed multiple discrete whitish mucosal lesion on rectosigmoid colon, and histologic findings were consistent with pseudomembranous colitis. The antituberculous agents were discontinued and vancomycin was administered. The patient's symptoms were resolved within several days. There was no recurrence after reinstitution of the antituberculous agents excluding rifampicin. We report here on a case of pseudomembranous colitis probably due to rifampicin.

니켈기 내열합금 절삭시 공구에 따른 마모와 칩생성

김우순,김경우,김동현 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.1

Nickel-based heat resisting alloys are commonly used for high temperature applications such as in aircraft engines and gas turbines. In this paper, the machinability of Nickel-based heat resisting alloy was investigated with respect to the wear and the chip formation by tool type and cutting condition. Relationship between three types of tool and chip formation Bras experimentally investigated. Among the three types of tool tested, coated tools(CVD, PVD) are available for the difficult-to-cut-materials such as Nickel-based heat resisting alloy and etc.

뇌수술 시 과호흡과 만니톨의 투여가 뇌혈류와 뇌산소대사에 미치는 영향

김지헌,김경식,문봉기,조경기,신용삼,이영주,김진수 대한마취과학회 2002 Korean Journal of Anesthesiology Vol.43 No.4

Background: There are therapies to lower intracranial pressure (ICP) including head elevation, hyperventilation, diuretics injection, intravenous mannitol, hypothermia, cerebrospinal fluid drainage, and cerebral resection in neurosurgical patients. However in recent reports, hyperventilation followed by mannitol administration may lead to cerebral ischemia. Therefore, we investigated the effect of 0.5-1.0 g/kg mannitol administration on jugular venous oxygen saturation (SjVO_2) and cerebral arterial-jugular venous oxygen content difference (AVDO_2) at PaCO_2 25-30 mmHg and 35-40 mmHg in patients undergoing neurosurgery. Methods: we studied 17 patients undergoing neurosurgery in the Ajou University Hospital. Anesthesia was induced with fentanyl, midazolam, thiopental, and vecuronium, and maintained with )_2-Air-Isoflorane, a continuous infusion of fentanyl, and vecuronium. Patients were divided into two groups. Group 1 (n = 10) which is PaCO_2 25-30 mmHg and Group 2 (n = 7) which is PaCO_2 35-40 mmHg by controlling ventilator. Measurements of SjVO_2 and AVDO_2 in following time intervals: Ⅰ = preinjection of mannitol, Ⅱ = postinjection 20 minutes of mannitol, Ⅲ = postinjection 40 minutes of mannitol were obtainde for each group. 0.5-1.0 g/kg mannitol was administered intravenously just at duramater opening. Results: Hemodynamics and hematologics were not significantly different among the two groups. SjVO_2 of each group are as follows; Group 1; Ⅰ (70.3 ± 8.1%), Ⅱ (66.3 ± 6.9%), Ⅲ (69.1 ± 7.9%) and Group 2; Ⅰ (78.6 ± 7.4%), Ⅱ (75.1 ± 8.1%), Ⅲ (76.0 ± 11.2%), Hyperventilation significantly decreased SjVO_2- AVDO_2 was not significantly different but SjVO_2 in Ⅱ was significantly decreased compared with Ⅰ and Ⅲ in Group 1 (20% patients). Conclusions: Mannitol produced a change of SjVO_2 during hyterventilation. Therefore, intravenous mannitol during hyperventilation should be given cautiously according to the patients status because it may cause cerebral ischemia in critical patients. (Korean J Anesthediol 2002; 43: 462~467)

Fatigue Measurement by Lifting Index

Kim,Dae-Sik,Kang,Kyong Sik 대한안전경영과학회 2000 대한안전경영과학회 학술대회논문집 Vol.2000 No.1

공구형상이 칩유동에 미치는 영향에 관한 연구

김경우,김우순,윤주식,채왕석,김동현 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

A new methodology is presented to evaluate material properties at high strain rates and high temperatures based on orthogonal metal cutting experiments and FEM simulations. Average strain rate and average temperature found in the deformation zone are computed and flow stress data at these conditions are modified until cutting forces calculated in simulations match those determined in experiments. Material properties obtained from this method were verified by additional metal cutting simulations. Derivation from cutting forces measured in experiments was less than 10%. The feasibility of tool design using FEM simulations is also demonstrated.