내분비계 교란물질의 검출계를 이용한 γ-HCH의 미생물에 의한 중간대사산물에 대한 내분비계교란 활성의 평가

이행석,박주석,조은민,문명숙,太田明德,류재천 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

To develop an efficient degradation system for Endocrine disruptors (EDs), it is necessary to have a good system to evaluate rapidly and accurately endocrine-disrupting activities of suspected chemicals and their degradation products. We previously constructed a co-expression system of GAL4 DNA binding domain (DBD)-human estrogen receptorβ ligand binding domain (hERβ LBD) and Gal4p transcriptional activation domain (TAD)-co-activator SRC1 in Saccharomyces cerevisiae with a chromosome-integrated lacZ reporter gene under the control of CYC1 promoter and GAL4 binding site (Upstream Activating Sequence, UAS). Expression of this reporter gene was dependent on the presence of estrogen or endocrine disruptors in the culture medium. Furthermore, the extent of transcriptional activation by those chemicals correlated with their estrogenic activities measured by other assay systems, indicating that this assay system is efficient and reliable for measuring estrogenic activity. We applied this assay system to measure estrogenic activity of microbial degradation products of γ-hexachlorocyclohexane (γ-HCH) by Sphingomonas paucimobilis. Among the γ-HCH metabolites, 2,5-dichlorohydroquinone (2,5-DCHQ) and chlorohydroquinone (CHQ) had similar estrogenic activities to the original chemical, but hydroquinone (HQ), a metabolite at later stage, had no activity at the concentration of 10^-4M, showing the necessity of evaluation of intermediate metabolites in microbial degradation systems.

생분해성 다공질 Calcium Phosphate 세라믹스의 제조

이경주,이중환,김석영 嶺南大學校 工業技術硏究所 1995 工業技術硏究所論文集 Vol.23 No.2

When porous calcium phosphate ceramics are used as a bone graft substitute, it is known that new tissue or blood vessel is grown into the porous implant due to their excellent biocompatibility. In this study, the most chemically stable β-crystalline form of calcium metaphosphate, Ca(PO₃)₂is prepared by the controlled thermolysis of monocalcium phosphate, Ca(H₂PO₄)₂. The diameter of cylindrical pores formed during cooling was controlled by a holding time at the melting point of a monocalcium phosphate and by the change of a recrystallization temperature, to obtain the most appropriate size(about 200㎛) of pores. It was observed that the increasing holding time at the melting point of monocalcium phosphate results in the decreases of pore sizes.

지지막을 이용하는 액막 추출기 내에서 아연 이온의 이동

주창식,이석희,이민규,홍성수,하홍두,정석기 한국환경과학회 2000 한국환경과학회지 Vol.9 No.2

For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured. Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D_2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.

유성견 급속 구개확장시 정중구개봉합부 및 치아주위 조직 변화에 관한 조직형태학적 및 면역조직화학적 연구

이주영,이진우,차경석 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.3

급속 구개확장은 정중구개봉합을 이개하기 위하여 강한 힘을 치아에 가하게 된다. 확장후 정중구개봉합부에 존재하는 골모세포와 섬유모세포의 증식 활성도를 측정하여 정중구개확장이 생리적으로 진행되는지를 확인하고, 이때 개개치아의 치주조직에서 나타나는 변화를 조사하기 위하여 약 10개월된 유성견 10마리를 대상으로 상악 제2소구치와 제1대구치에 Hyrax screw를 장착하였다 실험동물은 대조군 1마리, 1주 확장한 군 3마리, 2주 확장한 군 3마리, 2주 확장 후 2주 보정한 군 3마리로 구분하여, Screw를 1일 1/4회전시켜 확장하였고, 제2소구치, 제3소구치, 그리고 제1대구치 부위의 정중구개봉합부와 치주조직을 절취하여 Soft X-ray로 관찰하고,형태학적 및 면역조직화학적 변화를 광학현미경으로, 그리고 골개조를 편광현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1.편광현미경 소견에서는 대조군에 비하여 1주 확장군의 봉합부에서 골 형성과 흡수가 크게 증가되었으며, 2주 확장군에서 약간 감소를 보이다가, 보정군에서는 석회화가 크게 진행되었다. 2.면역조직화학적 연구에서는 대조군에 비하여 1주 확장군의 봉합부에서 골모세포가 PCNA(Proliferating Cell Nuclear Antigen)에, 미분화 섬유모세포가 EGF(Epidermal Growth Factor)에 약간 증가된 양성반응을 보였으며 EGF에 대한 골모세포의 반응은 낮았다. 2주 확장군에서는 섬 유아세포와 골모세포에서 PCNA와 EGF에 대한 양성 반응이 증가되었다. 보정군에서는 이들 PCNA와 EGF에 양성반응을 나타내는 세포들이 구개돌기 골단 주변에 집중되었다. 3.확장기간 중 봉합부 주변에서 광범위한 골 흡수와 골형성을 동반한 골개조가 일어났으며, 보정군에서는 다소 감소하였다. 2주 확장군과 보정군의 제3소구치와 제1대구치의 치근단에서 백악질 형성과 흡수가 나타났으며, 제1대구치의 협측 치경부에서 광범위한 초자양 변성대가 나타났다. 4.Soft X-ray소견에서 1주 확장군은 대조군에 비교하여 봉합부위의 여러부분에서 미세 파절과 저석회화된 결손부위를 보였다. 대조군과 보정군 사이에는 정중구개봉합부의 석회화 정도에 별 차이가 없었다. 2주 확장군과 보정군에서 제3소구치와 제1대구치는 협측으로 경사되는 경향을 보였다. The purpose of this study was to determine the proliferative activity of the osteoblasts and fibroblasts in the midpalatal area and to investigate the adjacent periodontal tissues of individual tooth following rapid expansion of the palate. Ten young adult dogs, aged approximately ten months, were used in the experiment. The experimental design was consisted of 1 week expansion group(Group E1, 3 dogs), 2 week expansion group(Group E2, 3 dogs), 2 week expansion and 2 week retention group(Group E3, 3 dogs), and control group(Group C, 1 dog). For each group, expansion screw was activated one time per day(1/4 turn;90˚) following Hyrax-screw application. The experimental animals in each group were sacrificed at 1, 2 and 4 weeks following palatal expansion. Maxillary tissue blocks were obtained and prepared for the histomorphologic and immunohistochemical studies. Light microscope, polarizing microscope, and soft X-ray apparatus were used in this study, and following results were obtained. 1.In polarizing microscopic study, the expansion groups(E1 & E2) showed blue color representing bone resorption and new bone formation in midpalatal suture area. E3 groups showed less blue color compared to the E1 and E2 group. But yellow color increased by calcification in the E3 groups. 2.Immunohistochemical study revealed that positive responses of the osteoblasts to PCNA and undifferentiated fibroblasts to EGF in E1 group were somewhat increased. Positive response to PCNA and EGF were increased in fibroblasts and the osteoblasts forming new bone in E2 group. In E3 group, the positive response cell concentrated the periphery of edge of palatal process in both PCNA and EGF. 3.Throughout the expansion period(E1 & E2), light microscopic study showed the edges of the extensive resorption and new palatal processes, indicating bone remodeling within the suture. E3 group exhibited less remodeling of midpalatal suture area. E2 group and E3 group showed cementum formation and resorption at the apex of 3rd premolar and 1st molar. E3 group exhibited extensive hyalinized zone on the cervical portion of buccal side of 1st molar. 4.Soft X-ray analysis of E1 group showed hypomineralized defect and microfractures in various parts of the suture areas when compared with control animals. There was no significant difference in the degree of mineralization in the midpalatal suture region between the C and E3 groups. Tooth axis showed tipping of 3rd premolar and 1st molar in the E2 group and E3 group. Based upon these experimental results, it is concluded that the undifferentiated mesenchymal cells always presented in midpalateal suture area following RPE. Differentiated osteoblasts and fibroblasts possess proliferating cellular activity until the 2 week retention period. The posterior teeth are tend to tip buccally as RPE force applied. Retention group exhibited irreversible response with severe hyalinized zone on the buccal surface of the first molar.

유사학과 조정 및 교양교과과정개편에 관한 연구

이종범,김규연,전지용,이춘의,홍석주 朝鮮大學校 1995 교과교육연구 Vol.17 No.-

웹페이지 레이아웃 개발 방법론으로서의 "웹-모듈러(Web-modulor)" 연구

이주희,장순석 동덕여자대학교 디자인 연구소 2001 디자인포럼21 Vol.4 No.-

본 논문은 황금비례를 활용한 웹 디자인 레이아웃의 사례 연구에 기반하여, 사용자의 사회적·문화적 배경을 초월한 형태적 만족감을 제고하기 위한 "웹-모듈러(Web-Modulor)"라는 새로운 개념의 웹페이지 레이아웃 개발 방법론을 제안한다. 사례연구에 있어서는 형태에 관한 심미적 지향성에 있어 인류보편의 규칙이 통용된다는 것을 입증하고 있는 황금비례에 대한 적용 사례들을 살펴본다. 본 논문에서 채택한 사례는 다국적 기업의 웹사이트 개발에 참여한 경험이 많은 세계 최대규모의 웹 에이전시 2개사의 웹사이트이다. 이러한 선행 사례 분석을 통해, 본 연구자는 황금비례의 원칙을 적용하여 웹사이트의 레이아웃을 효과적으로 디자인 할 수 있게 하는 수열인 "웹-모듈러"를 개발하고, 이를 적용해서 디자인 시안을 작성해 보았다. 본 연구결과로써 연구자가 개발, 제안하는 "웹-모듈러"의 개념은 웹사이트 개발의 경제성과 효율성을 증대 시키는 방법으로 응용될 수 있을 것이다. This article suggests a method based on the new concept of "Web-Modulor", analysing the previous cases of the layouts in web-design which apply the rule of golden proportion. This is to improve users` satisfaction of cognition of the forms, regardless of the users` geographic, social, and cultural backgrounds. First of all, this research is based on case studies of the web-sites of two gigantic web-agencies, which have made a number of web-sites of various global enterprises, as examples for analysis to verify the idea of the rule of golden proportion. This research also applies what is explored in the analysis of the previous cases to a plan for a web-site design. The researcher suggests the concept of 'Web-Modeler' which is the geometrical progression to help the layout of web-sites to be designed effectively. Eventually, this research implies that the new concept of 'Web-Modeler' can be applied as a method to improve the efficiency in development of web-sites.

대학 강의평가의 문제점과 개선방안

이석열,허영주 남서울대학교 2010 남서울대학교 논문집 Vol.16 No.1-2

Many universities have adopted the use of student ratings of teaching as the most authentic assessment tools for improving the quality of higher education. This article explores the significance and problems of students' evaluations of teaching effectiveness based on overview of issues in this area and searches improvement points. First of all, the significance of evaluations of teaching effectiveness are identified. The quality of teaching is not an objective entity which can be judged solely by the teacher. Rather, teaching is an interactive process between students and the teacher. Accordingly, students' ratings of teaching have full significance of evaluations of teaching effectiveness. In addition to that, several problems and limitations of students' ratings are criticized. Although it have some validity and usefulness of students' evaluations of teaching quality, it also have the potential bias and harmful side effects. Finally, it searches that special suggestion for improving students' evaluation and for it using to enhance the effectiveness of education, not to rank the courses and evaluate professors' achievement. Key Words : student's evaluations of university teaching, teaching effectiveness, significance and problems, improvement points

신체화장애 환자의 스트레스 대처방식 및 심리적 특성

이주연,이무석,윤진상,양종철,문지웅,정해원,은성종 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.6

Objectives : The purpose of this study was to investigate the stress coping strategies and psychological charactehstics, such as combined psychopathology and tendency of symptom interpretation, in patients with somatization disorder. Methods : Thirty patients meeting the criteria of DSM-IV somatization disorder were compared with thirty controls. We evaluated the subjects using Symptom Checklist-90-Revised (SCL-90-R), Somato-Sensory Amplification Scale (SSAS), Symptom Interpretation Questionnaire (SIQ), and The Ways of Stress Coping Questionnaire (SCQ). Independent t-test and Pearson correlation analysis were used. Results : From the results of SCL-90-R subscales, the scores of somatization, obsession-compulsion, depression, anxiety, and psychoticism were significantly higher in patients with somatization disorder than nonnal controls. Somatization disorder patients had greater amplification of physical sensation in SSAS and significantly higher score in physical interpretation of SIQ compared with psychological or environmental interpretation, In the SCQ of somatization disorder patients, we observed generallylower levels of total coping scores than the control group and significant positive correlation between passive coping style of SCQ and psychological interpretation of SIQ. Conclusion : These results show that patients with somatization disorder have various psychopathology, greater amplification of physical sensation, physical interpretation tendency of symptoms, and insufficient copying strategy.

small artificial defect(미소인공결함)

이승용,정재강,홍석주 朝鮮大學校 機械技術硏究所 1998 機械技術硏究 Vol.1 No.1

본 실험에서는 자동차의 전륜 구동축재(S43C, S50C)에 대해서 미소 원공결함을 가공한 비열처리재와 고주파열처리재의 피로시험편에 회전굽힘응력을 가하여 피로강도와 피로크랙의 발생 및 전파거동에 관하여 실험한 결과 다음과 같은 결론을 내렸다. 비열처리 S43C재 및 S50C재의 피로한도는 각각 98.1MPa, 107.9MPa이었고, 열처리재의 경우 각각 147MPa, 156MPa로서 열처리재는 비열처리재보다 약 50Mpa 증가하였다. 응력이 피로한도의 110%에서 120%로 증가하는 경우 비열처리인 S43C재 및 S50C재에서 피로수명의 감소율은 각각 약 49%, 약 45%였으며 또한 열처리재의 경우는 각각 약29%, 약 22%로서 비열처리재보다 열처리재가 피로수명 감소율이 낮게 나타났다. 평활재에서 표면 미시크랙의 발생은 비열처리재인 S43C 및 S50C에서는 수명비(N/Nf) 0.2정도에서 처음 관찰되었으며, 동일한 수명비에서 관찰된 미시크랙의 수는 S43C가 많았고, 평균 크랙길이는 S50C가 길었다. 피로크랙길이와 파단수명비의 관계 log(2a)=A+B(N/Nf)식에 본 실험재료를 적용한 결과 응력수준에 관계없이 잘 일치하였다 In this paper, an experiment to investigate the behavior of fatigue crack propagation in induction hardened structural carbon steel(S43C, S50C) with artificial defect are conducted by the rotary bending fatigue test in the room temperature. The summarized results are as follows: The fatigue limits obtained from experiments of as-received S43C and S50C were 98.1MPa and 107.9MPa respectively. The fatigue limit of heat-treated materials were 147MPa and 156MPa respectively. It means that the heat-treated specimens showed about 50MPa higher fatigue limits than the as-received material. When the applied stress was increased from 110% to 120% of fatigue limit, the decreasing rate of fatigue life was around 49% and 45% respectably in the as-received S43C and S50C, in case of the heat-treated materials, the decreasing rate of fatigue life was around 29% and 22% respectively. It means that the heat-treated materials had lower decreasing rate of fatigue life than the as-received materials. The initiation of surface micro crack was observed at 0.2 of fatigue life ratio in as-received S43C and S50C. The number of micro cracks in S43C were more than that of S50C, but the average crack length in S50C was longer than that of S43C at the same fatigue life ratio. Experimental results obtained from fatigue test were evaluated with the equation log(2a)=A+B(N/Nr). The relationship between crack length and cycle ratio showed a good agreement to the experimental results.

산국의 수량과 유효성분에 대한 NPK의 효과

이경동,양민석,정연규,손보균,조주식,이성태,김필주 한국농화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.2

본 연구는 3요소(N-PO_2O_5-K_2O)처리가 산국(Chysanthemum boreale M.)의 수량과 유효성분에 미치는 효과를 조사하여 효과적인 재배시스템을 개발하고자하였다. 처리구는 무처리, NPK(250-160-160), NK(250-0-160), PK(0-160-160kg/ha)의 5처리로 설정하여 산국을 재배한 결과, 건물수량은 NPK처리구가 PK처리구에 비하여 4.0배의 증수가 있었으며, 다른 처리구보다 무기이온의 흡수율, 생육 및 수량에서 NPK처리구가 가장 우수하였다. 식용으로 많이 쓰이는 꽃의 주요 아미노산은 proline, glutamic acid과 aspartic acid이였고, 다른 처리구들에 비하여 NPK처리구가 높은 함량을 보였다. 혈압강하효과가 우수한 cumambrin A는 PK처리구에 비하여 NPK처리구가 6.2배의 증수효과가 있었다. NK처리구는 NP처리구보다 cumambrin A의함량을 높이기 위해서는 인산의 시용보다 칼리의 시용이 더 요구되며, 야외포장에서의 인산과 칼리의 적정 시비량의 설정이 필요하다고 판단된다. To establish the fertilization condition to increase the productivity of Chrysanthemum boreale M. with high quality, the effects of three nutrients (N, P, K) on the yields and the effective components were investigated in the pot scale. NPK was applied by chemical fertilizers with N-P_2O_5-K_2O = 250-160-160 kg/ha as a main treatment, and NP (N-P_2O_5 = 250-160 kg/ha), NK (N-KO = 250-160 kg/ha), and PK (PO_2-KO_5 = 160-160 kg/ha) treatments were settled as comparison. Dry yields of C. boreale M. was increased significantly to 4 fold higher by nitrogen. Nitrogen increased apparently plant growth and inorganic nutrient uptake. In the flower, which is most useful and edible part as a herbal medicine, main amino acids were glutamic acid and aspartic acids, and the total content was increased significantly by three elements of application. In addition, the content of cumambrin A, which is known to have the effect of blood-pressure reduction, was increased source to 6.2 times by nitrogen higher than that in PK treatment. Potassium was more effective in biosyndiesis of cumatnbrin A than phosphorus, but the biological pathway was not clear, still.