자극특성 고분자 수화젤에 고정화된 효소의 촉매특성과 온도에 의한 효소활성의 조절에 관한 연구

김기훈,신영조 부산대학교 1994 生産技術硏究所論文集 Vol.47 No.

Poly(N-isopropylacrylamide) hydrogel is thermo-responsible which swells and shrinks reversibly as temperature changed through its phase transition temperature. When an enzyme is immobilized within this hydrogel, the catalytic activity of the immobilized enzyme can be switched on and off in accordance with the swelling and shrinking of hydrogel, respectively. In this work, invertase, sucrose hydrolase, was immobilized within poly(N-isopropylacrylamide) hydrogel and its catalytic activity as a function of temperature was studied. At 30℃, which is above the phase transition temperature of hydrogel, enzyme showed its activity. At 40℃ which is above the phase transition temperature, enzyme did not show its activity. Phase transition temperature of N-isopropylacrylamide hydrogel can be controlled by copolymerization with acrylamide. Poly(N-isopropylacrylamide) hydrogels which have different content of acrylamide were prepared and invertase was immobilized within those copolymer hydrogel. Enzyme activity of immobilized invertase within poly(N-isopropylacrylamide) hydrogel by temeprature was studied. In all the cases, immobilized invertase which is in below respective phase transition temperature showed its catalytic activity. Above phase transition temperature, immobilized invertase did not show its catalytic activity. Poly(N-isopropylacrylamide) 수화젤은 온도의 변화에 따라 가역적으로 수축과 팽윤을 하는 열응답성 고분자 수화젤이다. 이러한 온도에 민감한 수화젤에 효소를 고정화시키면 수화젤의 팽윤과 수축에 따라 효소가 그의 활성을 나타내던가 혹은 그의 활성을 나타낼 수 없는 이른바 온도에 따른 촉매로서의 효소활성의 "switch on-off" 기능을 기대할 수 있다. Poly(N-isopropylacrylamide)수화젤에 sucrose 분해효소인 invertase를 고정화시키고 sucrose hydrolysis의 반응온도를 조절하여 고정화된 invertase의 반응촉매로서의 온도에 따른 효소활성 조절에 대한 연구 및 고정화된 효소의 재사용에 관하여 고찰하였다. Poly(N-isopropylacrylamide)수화젤에 고정화된 효소를 사용하여 수화젤의 상전이 온도 이하인 30℃에서 sucrose를 분해반응시켰을 경우에는 glucose가 생성되었으나 수화젤의 상전이 온도 이상인 40℃에서 반응을 시켰을 경우에는 glucose의 생성이 정지되었다. 30℃와 40℃에서의 반복적인 반응온도의 변화에서도 효소는 그의 활성을 유지하였으며 반응 후 회수된 고정화효소는 재사용이 가능한 것을 관찰하였다. 여러 조성의 N-isopropylacrylamide와 acrylamide를 공중합시켜 Poly(N-isopropylacrylamide) 공중합 수화젤을 만들었으며, 공중합체의 조성에 따라 수화젤의 상전이온도가 변화되었다. 이 공중합체 수화젤에 invertase를 고정화하여 상전이온도의 변화에 따른 invertase의 효소활성에 대하여 연구하였다. 각 수화젤에 고정화된 invertase는 상전이온도 이하에서는 효소의 활성을 나타내지만 상전이온도 이상에서는 효소의 활성이 나타나지 않았다.

와인딩 공정에서 접압롤의 동특성에 관한 연구

김성수,김규태,천성민,신기현 건국대학교 산업기술연구원 1997 건국기술연구논문지 Vol.22 No.-

In a web winding process, the contact roll plays many important roles in air entrainment control and WIT(Wound In Tension) regulation. The behavior of the contact roll significantly affects the winding tension characteristics specifically at the time of contact and separation when the tangential velocities of contact roll and winding roll are not synchronized. A new mathematical model which includes the behavior of the web tension, the winding roll, the carriage and the contact roll is derived for the control of the winding tension. By using the model derived, a non-linear PID(NPID) controller is designed to control the winding tension at the time of contact and separation between the contact roll and the winding roll. Computer simulation study showed that the performance of the winding system with the NPID controller was significantly improved compared with that of a system with PID controller.

제약적 최소자승추정을 이용한 미분기반 다중계층 광류 추정

김영춘,신용달,권기구 永同大學校 2001 硏究論叢 Vol.7 No.1

본 논문에서는 광류 제약 방정식(optical flow constraint equation) 및 영상의 공간적인 상관성을 고려하여 제약적 최소자승추정(constrained least square estimation)을 이용한 미분기반 다중계층(multiscale) 광류 추정 방법을 제안하였다. 제안한 방법은 인접한 화소간의 움직임 속도가 유사하다는 가정 하에 다중계층으로 광류를 추정하였다. 또한 본 논문에서는 광류 제약 방정식 및 인접한 화소간의 움직임 속도가 유사하다는 가정에 의하여 발생하는 오차를 줄이기 위한 정제(refinement) 방법도 제안하였다. 제안한 방법이 기존의 방법에 비하여 더욱 정확하게 광류를 추정할 수 있음을 실험을 통하여 확인하였다. In this paper, we propose a gradient-based multiscale optical flow estimation method using the constrained least-square estimation, considering the spatial correlation of the image. The basic assumption of the proposed method is that the neighboring pixels are having a similar velocity. Also we propose a refinement method to decrease the error, reviving optical flow constraint equation and neighboring pixels are having a similar velocity. Experimental results show that the proposed method can more accurately estimate the optical flow than the conventional methods.

cis-platin에 의한 급성구토예방의 Dexamethasone의 4가지 정주량의 비교

김원,강지은,서영선,이동민,서정균,신병철,정기영,박유환,정춘해 조선대학교 부설 의학연구소 2002 The Medical Journal of Chosun University Vol.27 No.1

B5-hydroxytryptamine _3수용체(5-HT_3) 길항제와 dexamethasone의 동시투여가 cis-platin에 의한 급성 구토를 막는데 가장 효과적이다. 그러나 현재까지 가장 적절한 정주dexamethasone의 용량이 알려져 있지 않았다. 이에 dexamethasone의 4가지 다른 용량을 투여하여 그 효과를 비교하였다. 환자는 임의 추출되어 cis-platin 투여 45분전에 15분 동안 정주로 각각 dexamethasone 5, 10, 15, 20 mg을 투여 받았다. cis-platin 투여 30분전에는 ondansetron 8 mg이 부가하여 정주 되었다. 1999년 3월부터 2000년 2월까지 54명의 환자가 연구에 등록되어졌고 53명의 환자가 연구 대상으로 실험에 4군 (dexamethasone 5 mg 13명, 10 mg 14명, 15 mg 13명, 20 mg 13명)으로 나뉘어 평가 되어졌다. 급성구토와 구역질의 완전한 예방은 dexamethasone 5 mg을 투여 받은 환자에서 각각 69.2%, 60.9%, dexamethasone 10 mg을 투여 환자에서 69.1%, 61%, dexamethasone 15 mg 투여 환자에서 78.5%, 66.9%, dexamethasone 20 mg을 투여 환자에서 83.2%, 71.0%로 나타났다. 구토로부터 완전한 예방은 dexamethasone 20 mg을 투여 환자에서 5, 10 mg을 투여 환자와 비교하여 높았고, dexamethasone 15 mg을 투여 군에 비교하여서는 약간 우수한 효과만 있었다. 구역질으로부터의 완전한 예방도 월등한 것은 아닐지라도 20 mg을 받은 환자에서 높았다. 항 구토 치료는 특별한 불편 없이 조절되었고, 부작용의 발생에서 4가지그룹간에는 커다란 차이가 발견되지 않았다. Dexamethasone의 20 mg 정주양이 cis-platin으로 인한 급성구토를 예방하는데 가장 효과적인 예방량으로 사료되어진다. Background and objective: A 5-hydroxytryptamine _3(5-HT_3) receptor antagonist plus dexamethasone is the most efficacious antiemetic prophylactic treatment for the prevention of cis-platin induced acute emesis, but the optimal intraveous (Ⅳ) dose of dexamethasone is unknown. This prompted us to perform a randomized, double-blind, dose-finding study that compared four different doses of dexamethasone. Materials and Methods: Patients were randomized to receive dexamethasone, either 5, 10, 15, 20 mg, administered by 15-minute Ⅳ infusion 45 minutes before cis-platin. Ondansetron 8 mg was added to dexamethasone and was administered Ⅳ 30 minutes before cis-platin. From March 1999 to February 2000, 54 patients were enrolled onto the study and 53 were assessable according to the intention-to-treat principle (13 patients received 5 mg; 14 patients, 10 mg; 13 patients, 15 mg and 13 patients, 20 mg of dexamethasone). Results: Complete protection from acute vomiting and nausea was achieved by 69.2% and 60.9% of patients, respectively, who received 5 mg of dexamethasone, by 69.1% and 61.0% of those who received 10 mg, by 78.5% and 66.9% of those who received 15 mg, and by 83.2% and 71.0% of those who received 20 mg of dexamethasone. Complete protection from vomiting was significantly superior in patients who received 20 mg compared with those who received 5 and 10 mg of dexamethasone (P<05) and was superior, but not significantly, compared with those who received 15mg. Complete protection from nausea was superior, but not significantly, in patients who received 20 mg of dekamethasone. Multifactorial analysis confirmed these results. Antiemetic treatment was well tolerated, and no significant difference was found among the four groups in the incidence of adverse events. Conclusion: A 20mg single Ⅳ dose of dexamethasone should be considered the most efficacious prophylactic dose for the prevention of ois-platin induced acute amesis in treatment of cancer.

기하광학영역에서의 능동소나 표적신호합성

신기철,박재은,김재수,최상문,김우식 한국해양대학교 해양과학기술연구소 2001 硏究論文集 Vol.10 No.1

능동소나 시스템에서 표적신호의 근거리 정보가 중요해짐에 따라, 표적 음향산란 신호의 고유한특성을 분석하기 위해 실험적인 방법과 시뮬레이션 기법이 사용된다. 본 논문에서는 표적신호 합성을 위해 축소표적 반향실험을 수행하였고, 자료의 분석 결과 축소표적의 음향산란은 거울면 반사의 영향이 큰 것으로 분석되어, 표적신호 합성에서 기하광학이론을 응용하였다. 복잡한 형태의 표적을 여러 표본형상으로 분리하고, 각 표본형상의 기여도를 신호의 위상과 강도를 줌으로써 계산하였으며. 표적신호 합성모델의 검증을 위해 실제 축소표적 실험 결과와 비교하였다. 혁심용어: 기하광학이론. 음향산란, 거울면반사. 축소표적, 능동소나 투고분야: 수중음향 분야 (5.2) Since the near field iformation of target signal is important in the development and verification of active sonar system experimental method and simulation technique are widely used in order to analyze the detail characteristics of target scattered echoes. Therefore, in this paper, the scale target experiment is performed to develope and improve the target signal simulation model. Since the experimental results show that the specular reflection is the major component among scattering mechanisms, the target signal simulation model based on the Geometric Optics Theory (GOT) is developed. Complex target is separated into simple shapes, known as canonical shape. The contribution from individual canonical shapes are summed with proper phase and amplitude to produse the target strength of the whole complex body. Simulated target signal is compared with the experimental results fed discussed.

전동식 니켈 티타늄 파일의 표면 결함 및 단면 형태가 반복응력 하에서 피로 파절에 미치는 영향

신유미,김의성,김광만,금기연 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files (K3^(TM), ProFile®, and HERO 642®) with #30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups: control (no surface defects) and experimental group (artificial surface defects). A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the K3^(TM) (p〈0.05). There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic patterns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.

마케팅 실행의 문화적 측면에 관한 고찰 : 마케팅파워의 문화적 존중과 특수성을 중심으로

신왕우,김동훈,우기남 제주대학교 경상대학 경영경제연구소 2000 경영경제연구 Vol.2 No.-

換氣窓이 설치된 中庭形 아트리움의 여름철 熱環境에 관한 測定硏究

김영철,신기식,박상동,최무혁 대한건축학회 2004 대한건축학회논문집 Vol.20 No.6

The atrium in a building is a popular design skill due to its aesthetic, open appearance. It is relatively inexpensive to build and maintain atrium, and also we can expect energy saving effect. But its indoor space is thermally different from typical space because of its tall and large shape with top light. The upper part of atrium has the thermal problem of overheating during summer season. As one of the measures to solve this problem, the ventilation windows near the top light can be used. In this study, the vertical temperatures in the atrium were measured and analysed to understand the thermal environment in the atrium and the effect of ventilation window to reduce the overheating at the upper part of atrium. The ventilation windows were proved to have the effect to lower the temperature of the upper part of atrium as 3.8℃ at the condition of outdoor air temperature of 28℃.

아트리움이 있는 사무용건물의 실내조명환경에 관한 측정 연구

김영철,신기식,박상동,최무혁 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

Green Building is a sustainable building preserving the environment and saving energy and aims to provide the comfort indoor environment. KIER Green Building is the first Korean green building which was adopted the technologies of energy and resource conservation and in and outdoor environment preservation. In order to verify the luminous environment of green building and to convince the effect of daylight through atrium, the lighting environment element of KIER Green Building such as illuminance was measured and analyzed.

A Case of Hobnail Hemangioma

(Shin Taek Oh),(In Gang Jang),(Sung Wook Kim),(Baik Kee Cho),(Seung Dong Lee) 대한피부과학회 2002 Annals of Dermatology Vol.14 No.1

N/A Hobnail hemangioma(HH)is a benign acquired vascular tumor of endothelial origin which should be differentiated from other malignant vascular neoplasm such as Kaposi`s sarcoma or angiosarcoma.We report a case of hobnail hemangioma in a 21-year-old woman who had a dusky-red patch on her left shin.Histologically,ectatic vascular channels with a single layer of plumped endothelial cells were seen and the vascular channels seemed to dissect the collagen bundles.She underwent treatment with surgical excision with primary closure. (Ann Dermatol 14(1)45-47, 2002).