전기분사법을 이용한 키틴/키토산 미세입자의 제조

유용,박원호,민병무,이승진 梨花女子大學校 藥學硏究所 2003 藥學硏究論文集 Vol.- No.12

최근 의약학용 바이오 소재로 각광을 받고 있는 키틴과 키토산을 전기적인 힘을 이용하는 전기방사장치를 이용하여 미세입자 형태로 제조하였다. 키틴 또는 키토산 시료에 대하여 고분자 농도가 일정한 수준(사슬 간의 엉킴이 본격적 일어나는 농도) 이상에서는 초극세 섬유의 형태를 보였으며, 그 농도 이하에서는 비교적 균일하고 미세한 입자를 형성하였다. 키토산의 경우, 5% 초산 수용액에 녹여 4~5 wt%로 분사하였을 경우 200~400 ㎚ 크기의 미세입자를 제조할 수 있었다. 또한 농도가 증가할수록 입자의 크기가 커지면서 다소 불균일해지는 경향을 보였다. 수용성 글리콜 키토산은 분자량이 작기 때문에 높은 농도인 약 55 wt% 까지 미세입자가 생성되었다. 이 입자의 평균 크기는 약 300~500 ㎚ 정도를 나타내었다. 키토산을 초산 수용액에 녹여서 ???? 아세토산으로 ??????이 얻어진 N-아세틸화 키틴의 경우에는 ???????? ?????? 녹여 전기분사를 하였는데 7wt% 이하에서 균일한 미세입자가 생성되었다. 따라서, 키틴이나 키토산의 미세입자를 제조하기 위해서는 용매에 따라 일정한 농도와 점도와의 관계곡선으로부터 사슬 간의 엉킴현상에 의해 섬유상이 형성되지 않은 낮은 농도에서 전기분사를 실시하는 것이 무엇보다도 중요하다는 것을 알 수 있었다. Electrospray method is a new technique lo fabricate the polymer nanoparticles. Nanoparticles of chitin and chitosan were prepared by electrospray and characterized by scanning electron microscope (SEM). In general, the increase in the concentration of chitosan solution induced the increase in its solution viscosity. In addition, the solution viscosity increased rapidly at above the critical concentration, due to formation of entanglement between chitosan chains. From the plot of polymer concentration vs. solution viscosity, it was found that chitosan or chitin nanoparticles, with, particle size in the range of 200-600 nm, could be easily formed at below the critical concentration associated with the formation of chain entanglement. Therefore, we concluded that the plot of polymer concentration vs. solution viscosity was important to investigate the concentration range in which polymer nanoparticles could be prepared.

건조효과를 고려한 준설매립토의 압밀거동

유남재,박병수,이명욱,이주원 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.A

This research is to investigate the self-weight consolidation settlement and desiccation shrinkage settlement of soft marine dredging clay by performing numerical and experimental works. Large column test were carried out investigate the consolidation settlement considering effect of the self-weight and desiccation shrinkage, and centrifuge model test was also carried out investigate self-weight consolidation settlement. Results of centrifuge model and large column experiments about changes of settlement with time were analyzed by using the numerical technique of explicit finite difference method considering effect of the self-weight and desiccation based on the finite strain consolidation theory. Centrifuge model test results were in relatively good agreements with analyzed results in terms of self-weight consolidation settlement with time. Large column test results showed quite different values from the numerically estimated one, carried by experimental conditions.

마이크로 팩토리를 위한 방전 가공 시스템 개발

유병한,김태곤,정재원,허세곤,고석훈,박성수,정영훈,민병권,이상조 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

마이크로 팩토리 시스템에서 마이크로 방전 가공 시스템은 많은 장점을 가진다. 전통적인 가공 시스템과 달리 비접촉 가공 방식이기 때문에 소형화에 따른 강성저하 문제에서 자유로우며, 정밀 가공이 가능하다. 그러나 방전가공에서 사용하는 전극에서, 가공 중 발생하는 마모 문제는 생산성뿐만 아니라 가공 정밀도를 떨어뜨리는 문제를 발생시킨다. 이번 연구에서는 전극의 마모 문제를 보완할 수 있는 방전 드릴링 가공과 밀링 가공에서의 공정 제어기법을 제안하였다. 또한, 마이크로 팩토리 용 테스트베드의 방전 가공 모듈로 디스크형 미세 전극 드레싱 가공 시스템, 자동 공구 교환 장치 시스템, 소형 유체 순환 시스템 등도 개발하였다.

악성 섬유성조직구종에서 ras 유전자의 돌연변이

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

인체 연부조직 육종에서 Cyclin D1, CDK4,p16 및 Rb 단백의 발현

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

현역 군인 발생을 중심으로 본 2000년도 국내 삼일열 말라리아 발생 현황

박재원,김영아,염준섭,유정식,양병국,채종일 대한감염학회 2001 감염 Vol.33 No.4

Background : Since 1997, the annual case occurrence of vivax malaria in the Republic of Korea have exceeded 1,000 cases since 1997. The military is thought to be an important source of the current outbreak. We collected various informations about malaria cases (soldiers, veterans and civilians) which occurred in 2000, and analyzed the characteristics of the current outbreak. Methods : Informations about malaria cases of soldiers, veterans and civilians, including name, age, sex, day of onset, region, etc., were collected through the National Institute of Health. Results : Out of total 4,141 cases, 1,288 (31.1%) occurred in the military, 1,273 (30.7%) occurred among the veterans, and 1,580 (38.2%) occurred among civilians. The monthly case occurrence reached its peak in early August. Areas such as Cheolwon, Yeoncheon and Paju showed the highest prevalence. Conclusion : It is considered that the current malaria outbreak has escaped from the exponential growth phase, however, more attention should be paid to prevent further spreading of malaria infection. (Korean J Infect Dis 33:280∼284, 2001)

간암세포에서 저산소증에 의해 유도되는 VEGF의 발현기작에 대한 연구

권유욱,배수경,김정애,김규원,박병채 부산대학교 유전공학연구소 1997 분자생물학 연구보 Vol.13 No.-

Purpose: Hepatocellular carcinoma(HCC),a typical hypervasculized tumor is very sensitive to hypoxia and vascular endothelial growth factor(VEGF) has previously been identified to be up-regulated in response to hypoxia in several cell types. However, the molecular mechanisma by which hypoxia is sensed by the cells remain enigmatic. To investigate whether calcium and AP-1 are involved in hypoxia-sensing mechanism, we performed following eaperiments. Materials and Methods: Hep3B cells were grown in hypoxia condition. To assess cell viability, MTT assay was performed. To investigate the effect of calcium and AP-1,northern blot analysis was performed after treatment with BAPTA/AM. Results: The expression of VEGF was significantly up-regulated by hypoxia in Hep3B, hepatocellular carcinoma cell line. The increased expression of VEGF induced by hypoxia was blocked by the addition of BAPTA/AM, a cytosolic calcium chelator to the media. In addition, we found that the expression of c-jun protooncogene was also-regulated by hypoxia. Hypoxia increase of c-jun expression was also normalized by the treatment with BAPTA/AM. Conclusion: These results suggest that the increased expression of VEGF by hypoxia is mediated through the calcium and c-jun signalling pathway in the Hep3B human hepatoma cell lines.

재발성 류마티즘 환자에서 발작의 유발인자

주유철,이동민,양종태,신병철,임태영,서정균,정기영,최동헌,김원,조영신,고희관 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.2

Background and Objectives : Palindromic rheumatism (PR) is known to be triggered without any obviously inciting events in most patients, although, in a few cases, attacks have been noted to relate to another events such as weather change, childbirth, ingestion of certain foods, or over-exercise. The aim of this study was to characterize the triggering factors on palindromic attacks. Materials and Methods : We evaluated sixty-four patients with PR for the presence of triggering factors and the relationship between attacks and triggering factors by interview of patients. We considered that there was an probable association between episodes and PR, if episodes within 24 hours prior to PR had triggered at least 50% of all attacks and a definite association between episodes and PR, if episodes within 24 hours prior to PR had triggered 100% of all attacks. Results : In 15 patients (35.9%), there was a possible association between episodes of PR and initiating events. In 8 patients (12.5%), there was a definite association between episodes of PR and initiating events. The triggering factors were physical over-activity including exercise (19/64: 29.7%), foods, such as rawfish, crab, and chicken, including alcohol (19/96: 19.8%). However, there were no difference between the groups with and without the triggering factor in sex ratio, duration and onset of PR, the positive rate of rheumatoid factor and involved sites. Conclusion : Our observations showed that PR was triggered by physical over-activity more than in previous reports and hypersensitivity to foods was a causative factor in some patients with PR. However, patients with triggering factors had a similiar clinical profile to patients without triggering factors.

4-(2-Pyridylazo)-resorcinol에 의한 Gallium 및 Indium의 흡광 광도정량

林炳五,孫太源,柳館杓 弘益大學校 1983 弘大論叢 Vol.15 No.2

Several condition for the spectrophotometric determination of gallium and indium with 4-(2-Pyridylazo)-resorcinol [PAR] have been studied. The color solution of gallium-PAR, indium-PAR shows a maximum absorption at 504nm, 510nm, and follow Beer's law over a range of a to 15㎍/25ml, 2 to 30㎍/25ml of gallium and indium The molar extinction coeffecient at 504nm, 510nm are estimated to be 102,000, 86, 400. The absorbancy of the solution is kept constant for 20hrs and is not affected by temperature between 13~35℃. Since iron(Ⅲ), cobalt, copper, bismuth, zinc. cadmium, aluminium interfere more or less, the seperation of gallium and indium from some of the above ions by means of ether extraction has been studied. the constitution of the complex examined by continuous variation method is that the molar ratio of gallium:PAR, indium-PAR are 1:2.

거대 점오염원이 주변 대기질에 미치는 영향에 관한 연구

김유근,이화운,전병일,장은숙,홍정혜,문윤섭,원경미,송정희 부산대학교 환경문제연구소 1996 環境硏究報 Vol.14 No.1

In order to show the effect of a vast point pollutant source on air quality of Pusan Thermoeletric Power Plant and its surrounding area, air quality around Pusan Thermoeletric Power Plant was simulated by ISCLT-2 which was supplied by EPA. For this purpose the emission amount of SO_2, NO_2 and TSP was calculated and atmospheric stability was classified for a recent decade(1985~1994) in Pusan. A result of the emission amount showed that much amount of NO_2, NO_2 and TSP are emitted from industrial area. It was clear that NO_2 is much emitted from line source and industrial area. And as a result of classification of atmospheric stability, neutral, stable and unstable state were 58%, 24.1% and 17.9%, respectivly. The result of ai quality simulation by ISCLT-2 showed that Pusan Thermoeletric Power Plant is affecting on the increse of 2.0ppb, 3.0ppb and 5.0㎍/㎥, SO_2, NO_2, and TSP respectively at its surrounding area, site A-3 which was located westward 2.2㎞ distance from Plant