돼지 신장세포(PK15)의 이종이식 거부반응에 대한 재조합 IL-18의 영향

최연실,김은미,김영관,박상연,심정현,윤도영,강형식,명평근 충남대학교 형질전환복제돼지연구센터 2004 논문집 Vol. No.8

Various cytokines including IL-1β, IL-2, IL-4, IL-10, IL-12p40, IFN-r, and TNF-α have been recently reported to play important roles in both host and donor cell activations during xenotransplantation. Interleukin (IL)-18, a proinflammatory cytokine, can induce IL-4 and IL-13 production in T cells, NK cells, B cells, mast cells, and basophils. IL-18 has the capacity to stimulate innate immunity and both Th1-and Th2- mediated responses, but little is known to involve in the xenograft rejection. In order to investigate the role of IL-18 in xenograft rejection, we transplanted the pig kidney (PK15) cells to C57BL/6 mouse with or without intraperitoneal injection of mouse recombinatant IL-18, It was analyzed the population of T cell, B cell and NK cell in the mice transplanted with PK 15 cells and recombinant IL-18 by flow cytometry. We found that splenic CD3+ T cells were increased in mice injected PKl5 cells with recombinant IL-18. These results suggest that recombinant IL-18 is critical in the xenograft rejection by increasing T cell population of the recipients.

鐵筋콘크리트 土留構造物의 最適化에 關한 硏究

崔洪植,邊根周,李相旻 연세대학교 산업기술연구소 1984 논문집 Vol.16 No.2

A mathematical model is formulated for the minimum cost design of reinforced concrete earth structures. The design variables are selected to be the depth and steel ratio in the retaining wall, and the depth, steel ratio and footing sizes in the isolated column footings. An elastic analysis is performed and resulting designs are based on both the ultimate strength theory and the elastic theory of concrete design. Constraint requirements are imposed to insure structural strength and side constraints. The resulting mathematical model is a nonlinear constrained optimization problem. The modified Lagrange Multiplier method is suggested as a satisfactory algorithm for the optimum design of the R.C. earth structures.

기제와 피부투과촉진제가 아포모르핀의 피부투과에 미치는 영향

최영근,최옥,김건남,박은석,지상철 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

In order to evaluate the effects of vehicles and penetration enhancers on skin permeation of apomorphine, the skin permeation rates of apomorphine from vehicles of different composition were determined using Franz diffusion cells fitted with excised rat skins. Solubility of apomorphine in various solvents was investigated to select a vehicle suitable for the percutaneous absorption of apomorphine. The solvents used were propylene glycol (PG), Transcutol^??, Labrasol^??, Labrafac hydro WL^??, Labrafil WL 2609 BS^?? and isopropyl alcohol. Even though permeation rates of apomorphine from each vehicle were low (0.08-0.36㎍/㎠/hr), the combination of PG and Labrafac^?? increased it significantly. The permeation rates of apomophine from PG/Labrafac^?? mixtures increased as the volume fraction of PG in the mixture increased. The maximum permeation rate of 18㎍/㎠/hr was achieved at 30% of PG, which decreased with further increase of PG fraction. A series of fatty acids, alcohols and monoterpenes were employed as penetration enhancers. Incorporation of each enhancer in the PG/Labrafac^?? (30:70) mixture at the level of 10% improved the skin permeation significantly. The highest permeation rate, 117㎍/㎠/hr, was attained with myristic acid.

運動種目別로 본 PWC_(170)時에 發現되는 運動能力에 관한 比較硏究

최영근,김상국,김정주 경희대학교 체육대학 한국체육과학연구소 1984 體育學論文集 Vol.12 No.-

With two Gymnastics players, three Basketball players, four Baseball players, four Football players as the Subjects, this study was made in order to reveal the degree of Physical Work Capacity (PWC) 170 by measuring how Heart Rate would change when they run on the Treadmill. The Results are as following: 1. In max Heart Rate, Baseball players were the highest as 209.00±4.90 beats/min, Gymnastics players were 195.50±3.54 beats/min, Football players were 192.00 ± 7.02 beats/min and Basketball players were the lowest as 187.00 ± 8.89 beats/min. 2. In max Running time and Running distance, Football players were the highest, 11.66 ± 0.59 minutes as Running time, 2450.3 ± 151.28m as Running distance, Basketball players were 11.21 ± 1.73 minutes and 2358.9 ± 381.77m, Baseball players were 10.69 ± 0.47 minutes and 2256.9 ± 104.60m and Gymnastics Players were the lowest, 8.50 ± 0.03 minutes and 1721.80 ± 9.90m. 3. In Heart Rate increase while they run on Treadmill, it was totally the highest in Baseball players, and was appeared orderly in Gymnastics players, in Football players, and in Basketball players. % HR max was appeared generally that Gymnastics players were appeared the highest, and was appeared orderly Baseball players, Basketball players, Football players. 4. In Heart Rate change while the Recovery, the Basketball players were appeared generally low Heart Rate at the Sometime, and was appeared orderly Football players, Gymnastics players, Baseball players. % H.R. max, Basketball players was recovered the fastest speed. Within 4min recovery it was appeared quickly that was orderly Basketball players, Baseball players, and after 4min was appeared orderly Basketball players, Gymnastics players, Baseball players, Football players. 5. In PWC 170 test, Basketball players were appeared superior that 9.09 min in Running time and 1781.0m in Running distance, and 240m/min in load and 6% in slope. And next Football players were appeared 7.27 min in Running time, 1463.4m in Running distance, 220m/min in load, and 5% in slope, Gymnastics players were appeared 5.53 min in Running time, 968.0m in Running distance, 200m/min in load and 4% in slope. Baseball players were appeared inferior that was 12 min in Running time, 704.0m in Running distance, 200m/min in load, and 4% in slope.

나노 사이즈 TiO_2 광촉매를 이용한 페놀 분해

최상근,김동주,김교선 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

In this study, we prepared nano-sized TiO2 particles for various process variables by the diffusion flame reactor and we collected TiO2 particles by thermophoresis. It is found that the size of TiO2 particles increases, as the flame temperature or the inlet TiCl4 concentration increase or the total gas flow rate decreases. We investigated the photo-degradation of phenol wish the prepared TiO2 particles. We found the optimum amounts of TiO2 photocatalysts for our experimental apparatus and investigated the photo-degradation efficiencies of phenol, changing the process variables such as size of TiO2 photocatlysts, phase ratio of rutile/anatase, concentration of phenol, input ratio of O2. Degradation efficiencies of phenol were almost 95% in 15 minutes for the standard conditions of our experiments.

흡착특성이 다른 내분비계 장애물질 3종, Amitrol, Nonylphenol, Bisphenol-A의 GACs에서의 흡착 특성

최근주,김상구,권기원,지용대,김승현,김창원 한국물환경학회 2004 한국물환경학회지 Vol.20 No.3

Adsorption characteristics of three endocrine disruptors, amitrol, nonylphenol, and bisphenol-A, were evaluated depending on the type and service duration of activated carbon (AC). Bituminous coal-, wood-, and coconut-based coals were tested. Bituminous coal-based AC (BCAC) had the greatest sorption capacity for the three chemicals tested, followed by wood-based AC (WAC) for nonylphenol and coconut palm-based AC (CAC) for bisphenol-A. During the column test, amitrol removal efficiency increased over time, indicating that hydrophilic endocrine disruptors are biodegraded in the AC column. Removal efficiencies of hydrophobic compounds such as nonylphenol and bisphenol-A decreased over time since the main removal mechanism was adsorption. The order of the amitrol removal was: BCAC-5.9 yr , CAC-3.1 yr > BCAC-2.2 yr > BCAC-virgin > CAC-virgin > WAC-virgin > WAC-3.1 yr. In general, used AC had greater removals than virgin AC. The order of the bisphenol-A removal was: CAC-virgin > BCAC-2.2 yr > CAC-3.1 yr > WAC-virgin > BCAC-5.9 yr > WAC-3.1 yr. The order of the nonylphenol removal was: BCAC-virgin > WAC-virgin > CAC-3.1 yr ,WAC-3.lyr> BCAC-2.2 yr > BCAC-5.9 yr > CAC-3.1 yr. Bituminous coal AC performed the best over time. Endocrine disruptors such as these three compounds appear to be removed effectively by activated carbon through biodegradation and adsorption. Wood and coal based among the virgin ACs and 3.1 years used wood base among the used ACs appeared the lowest carbon usage rate(CUR) for nonylphenol removal by prediction model. Virgin and used coconut base ACs except BCAC had the lowest CUR for removal Bisphenol-A. Biodegradation of nonylphenol and Bisphenol-A did not occurred during the 9,800 bed volume experiment period. BCAC had the highest biodegradation capacity of 46% for amitrol among virgin ACs and the used coal based ACs had 33-44% higher biodegradation capacity than virgin's for amitrol so biodegradation is the effective removal technology for hydrophilic material such as amitrol.

모드해석에서의 경계조건 영향

최연선,박근영,배성준 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1

Modal analysis is a fundamental procedure to analyze the dynamic characteristics of structures or machines. Modal analysis is composed of theoretical modal analysis using finite element method and experimental modal analysis. The discrepancy between these two makes modal analysis difficult and ususally comes from misunderstandings on boundary conditions of the structure. Boundary condition effect in modal analysis is investigated theorectically and experimentally in this study for a rod and a beam. The result shows that boundary condition affects on lower modes, but can be ignored for higher modes. Boundary condition can be modeled by a spring and a damper having finite values. Using this spring and damper model, the boundary conditions of a theoretical modal analysis model can be corrected by comparing the results of experimental modal analysis.

확산화염 반응기를 이용한 TiO_2 광촉매 제조 및 페놀 및 톨루엔 광분해 응용

최상근,김교선 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.B

We prepared the nano-sized TiO_2 particles by the diffusion flame reactor and investigated the effects of several process variables on the generation and transport properties of TiO₂particle. As the length from the tip of diffusion flame reactor increases, the size of TiO_2 particle increases by the coagulation between particles. The structure of TiO_2 particles prepared is almost found to be anatase. It was found that the TiO_2 particle size depends more largely on the change of reactor temperature than on the change of inlet TiO_4 concentration. By the photo-degradation experiment of phenol and toluene with the prepared TiO_2 particles, we found that the photo-degradation efficiencies of phenol and toluene change, depending on the process variables such as size of TiO_2 photocatlysts, concentration of phenol or toluene. Degradation efficiencies of phenol and toluene was above 90% in our experiments in 60 minutes.

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.

선택적 레이저 소결법을 이용한 기어박스의 정밀주조기술 개발

최상련,김천기,박근,오철호 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.1

In this paper, rapid prototyping and precision castiong technology have been devloped for the manufacturing of inlet pear box of an airplane. Rapid prototyping is a new prototyping technology that produces complicated parts directly from threedimensional CAD data with a high efficiency, and has been extensively applied to various manufacturing processes. In the present work, Selective Laser Sintering(SLS) system is untilized in order to manufature prototype of the inlet gear box. Prototyping technology using SLS is also investigated from the viewpoint of accuracy. Using the SLS master, the casting products are manufactured through several processes such as: vacuum casting, lost wax shell casting and investment cast-ing. The shrinkage characteristics of wax and cast iron in the casting procedures are considered, and then reflected to the design procedure so that the accuracy of the product in improved consequently.