Methotrexate가 Mouse 간세포의 미세구조에 미치는 영향

정호삼,장혁순,이규식 한양대학교 의과대학 1987 한양의대 학술지 Vol.7 No.2

Methotrexate (MTX), folic acid analog, has been widely used in the therapy of psoriasis and also used in the chorionic adenoma and acute lymphatic leukemia. Methotrexate inhibits not only DNA synthesis but also RNA and protein synthesis. It has been reported that during the therapy, its cytotoxicity leads to necrosis of the epithelium of the renal tubules, hair loss and hepatic fibrosis. So the author undertook the present study to pursue the effect of methotrexate on the cytoplasmic organelles of hepatic cells. Albino mice, ICR strains, weighing 20gm were used experimental animals. The experimental animals were killed at 24, 48, 72 and 96 hours after administrations of 15 mg/kg of MTX. The specimens obtained from liver were prefixed in Millonig's solution and post-fixed in the 1% osmic acid. After specimens were dehydrated and embedded in the Epon 812, ultrathin sections were made and double stained with uranyl acetate and lead citrate. And these preparations were observed with the electron microscope. The results were as follows. 1. The majority of mitochondria was hypertrophied and some mitochondria were irregular shaped, its double membrane and crests disappeared in the mouse liver of the 24 hours-MTX treated group. 2. Golgi complexes were atrophied in the 48 hours-MTX treated group and cisternae of the Golgi apparatus were hypertrophied and vesicular formation was observed in the 72 hours-MTX treated group. 3. The cisternae of the rough endoplsmic reticulum wer dilated and sacculated, but the detachment of membrane bound ribosomes was observed. 4. Lysosomes and autophagic vacuoles were increased in number with time. Consequently, it is suggested that MTX would induced the damge of the organelles of the hepatic parenchymal cells in mice.

점도, 시편형태 그리고 접착의 유무가 광중합 복합레진의 선형중합수축의 측정에 미치는 영향

이인복,손호현,권혁춘,엄정문,조병훈 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.6

Objectives. The aim of study was to investigate the effect of flow, specimen geometry and adhesion on the measurement of linear polymerization shrinkage of light cured composite resins using linear shrinkage measuring device. Methods. Four commercially available composites an anterior posterior hybrid composite Z100, a posterior packable composite P60 and two flowable composites, Filtek flow and Tetric flow were studied. The linear polymerization shrinkage of composites was determined using 'bonded disc method' and 'non bond ed' free shrinkage method at varying C factor in the range of 1~8 by changing specimen geometry. These measured linear shrinkage values were compared with free volumetric shrinkage values. The viscosity and flow of composites were determined and compared by measuring the dropping speed of metal rod under constant load. Results. In non bonded method, the linear shrinkage approximated one third of true volumetric shrink age by isotropic contraction. However, in bonded disc method, as the bonded surface increased the linear shrinkage increased up to volumetric shrinkage value by anisotropic contraction. The linear shrinkage value increased with increasing C factor and approximated true volumetric shrinkage and reached plateau at about C factor 5~6. The more flow the composite was, reduced linear shrinkage was measured by compensation radial flow.

어머니가 지각한 아버지의 양육참여도 및 어머니의 양육효능감과 유아의 또래놀이행동의 관계

이충량, 문혁준 가톨릭대학교 생활과학연구소 2011 생활과학연구논집 Vol.31 No.1

급성 심근경색증을 동반한 혈전성 혈소판 감소성 자반증 1예

이태희,김진혁,김완중,박지영,강흥선,조정휘,김권삼,송정상,배종화 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.11

MANET 라우팅 프로토콜 QoS 지원서비스의 성능평가에 관한 연구

鄭燦赫,金鉉郁,李光培,姜景仁,朴京培,劉忠烈,吳世德,裵振勝,趙榮泰 明知大學校 産業技術硏究所 2004 産業技術硏究所論文集 Vol.23 No.-

In this paper, we evaluated two main QoS supporting routing protocol on wireless ad hoc network. At presence, wireless mobile communication focuses on how to efficiently support mobility of users more than QoS guarantee. However, in order to satisfy requirement of various applications which have been or will be served, QoS support service between source and destination becoming a very important issue. Of all routing protocols, DSR and AODV are very important routing protocol in MANET. So we simulated DSR and AODV QoS Routing Protocol Through simulation evaluation tool NS(Network Simulation) based on various environments.

Lysozyme 陽性 胃癌細胞 및 大障癌 細胞에 對한 免疫組織化學的 硏究

吳忠南,李珉徹,曺圭赫 全南大醫大 1985 전남의대학술지 Vol.22 No.2

大學卒業定員制의 實施에 따른 學生生活 指導方案에 關한 硏究

崔根爀,張忠根,李相祐,張鎭吉,張大熙 충남대학교 1982 學生生活硏究 Vol.10 No.1

Higher education in Korea is faced with a new situation since 1981 when the government implemented a college graduation quota system designed to broaden the opportunities for higher education, alleviate the problem of the students who fail the entrance examination, and improve the quality of college graduates. The change of the system has brought about several serious problems including how to supply enough faculty members, how to provide enough educational facilities, and how to cope with the huge increase in the number of students, 30% more than graduation quota. The greatest single problem resulting from the implementation of college graduation quota system is the psychological and emotional unease aroused among the students, because 30% of those students with unsatisfying results must be banished from college before their graduation. This study aims to find effective measures for student guidance that each of the colleges can implement to help students adjust to the changed circumstances. After objectively investigating the problems from the various educational environments, from the recent students' views of college, and from the psychological and emotional unease arising in them by the fear of failing to graduate from their college because of implementation of the graduation quota system, a survey was conducted by means of a questionnaire composed of 40 questions and by means of personal interviews, 5,903 students, who are influenced by the graduation quota system, attending 19 public and private universities and colleges selected throughout the country. The data obtained from this survey were statistically processed with the help of the C. N. U. Computer Center, and the ratios of the responses to each of the questions were analyzed and calculated according to the distinctions of the total, sex, region, and major. The conclusions that the interrelations among the variant factors from each of the questions which were surveyed, analyzed and arranged have suggested are as follows : 1. The original purpose of graduation quota system should continually be clarified and communicated to all students and a concrete, specialized guidance system should be established to guide the minority of the students (13%) who don't fully understand the basic properties of higher educational institutions. 2. The institutions should provide enough educational facilities and supply enough faculty memebers to solve the problem of accomodating the large numbers of students. At the same time, they should suggest how students should learn positively and effectively to gain an expert knowledge, and how professors should gain public confidence in grade evaluation. Accompanying those measures, the government should develop a good policy to expand and distribute job opportunities to college graduates. 3. The admission quota should be controlled depending on the rate of naturally failed students, and then the students' unease and suppression caused by excessive competition can be relieved. In addition, it is advisable that the banished students should be allowed to transfer to University of the Air without regard to their grades. 4. An education devised to let students have a sound sense and way of thinking should be accompanied by a guidance system which their seniors, parents and society take part in. 5. An atmosphere conducive to sweet and well-rounded friendship among classmates should be created, sound extra-curricular activities should be encouraged and the number of students and adviser professor is in charge of should be lessened to a reasonable number.

충주시 고등학생의 최근 4년간(1988-2001) B형간염 표면항원 및 항체 양성률 조사

김형수,이건세,장성훈,박수경,김청식,이창희,권혁중,정순섭 한국역학회 2002 Epidemiology and Health Vol.24 No.2

Objective : Since Korea has been known to be of the endemic area for hepatitis B virus(HBV) infection, vaccination for HBV has been recommended for all neonates in Korea. After starting vaccination in 1983, the change of sero-positivity of HBsAg and HBsAb is expected. This study was carried out to investigate the seropositive rate of hepatitis B virus surface antigen and antibody in high school freshmen students in Chungju-city. Methods and Materials : From 1998 to 2001, a total of 11,735 who were born in 1982 to 1986, were enrolled in this study. HBsAg and anti-HBs were tested by reversed passive hemagglutination and passive hemagglutination, respectively. Results : The study population was 11,735 students who were composed of 5,813 males (49.6%) and 5,914 females (50.4%). The HBsAg sero-positivity of male and female students was 3.25% (n=381) and 2.59% (n=153) respectively. The anti-HBs sero-positivity of male and female students was 62.2% (n=3,154) and 64.1% (n=2,969) respectively. There are significant difference observed in comparison of HBsAg and anti-HBs seropositivity according to sex (p<0.05). From 1982 to 1986 on birth year, anti-HBs sero-positivity has been increased significantly from 63.3% to 73.3%. But the change of HBsAg sero-positivity has not been changed significantly. Conclusions : As compared with previous studies of HBsAg and anti-HBs, the sero-positive rate of HBsAg has not been changed but that of HBsAb has been increased significantly. This result revealed that the effect of HBV vaccination program was successful.

유동성 및 응축성 복합레진의 점탄성에 관한 유변학적 연구

조병훈,이인복,권혁춘,손호현,엄정문 대한치과보존학회 2000 Restorative Dentistry & Endodontics Vol.25 No.3

The purpose of this investigation was to observe the viscoelastic properties of five commercial flowable(Aeliteflo, Flow it, Revolution, Tetric flow, Compoglass flow) , three conventional hybrid(Z-100,Z-250,P-60) and two condensable(Synergy compact, SureFil) resin composites. A dynamic oscillatory shear test was done to evaluate the storage shear' modulus (G' ) , loss shear modulus(G") , loss tangent(tan δ) and complex viscosity(η* ) of the resin composites as a function of frequency dynamic frequency sweep test from 0.01 to 100 rad/s at 25℃ - by using Advanced Rheometric Exparusion SystemtARES) . To investigate the effect On the viscosity of resin composites of filler volume fraction, the filler weight % and volume % were measured by means of Archimedes' principle using a pyknometer. The results were as follows 1.The complex viscosity η* of flowable resins was lower than that of hybrid resins and significant differences were observed between brands. The complex viscosity η* of condensable resins was higher than that of hybrid resins. The order of complex viscosity η* at ω = 10 rad/s was as follows. Surefil, Synergy compact, P-60, Z-250, Z-100. Aeliteflo, Tetric flow, Compoglass flow, Flow it, Revolution. The relative complex viscosity of flowable resins compared to Z-100 was 0.04-0.56 but Surefil was 30.4 times higher than that of Z-100. 2.The storage shear modulus G' and the loss shear modulus G" of flowable resins were lower than those of hybrid resins but those of condensable resins were higher. The patterns of the change of loss tangent, tan δ of resin composites with increasing frequency were significantly different between brands.The phase angles,δ, ranged from 30.2-78.1˚at ω = 10 rad/s. 3.A11 composite resins represent pseudoplastic nature with increasing shear rate. 4.The complex shear modulus G* and the phase angle δ was represented by the frequency domain phaser form, G*( ω )= G* eIδ = G*〈 δ. The locus Of frequency domain phaser plots in a complex plane was a valuable method that represent the viscoelastic properties of composite resins. 5.There was no direct linear correlationship but a weak positive relation was observed between filler volume % or weight % and the viscosity of the resin composites.

Flowable Composite Resin의 미세변연누출 및 전단결합강도

박성준,오명환,김오영,이광원,엄정문,권혁춘,손호현 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.4