단세포 나팔벌레,Stentor coeruleus의 빛에 의한 ATP 합성

Chen, B.H.,허재욱,민태진,Iwatsuki, K,송필순 동국대학교 자연과학연구소 1986 자연과학연구 논문집 Vol.6 No.-

나팔벌레의 세포내 ATP 함량은 0.5~2초동안 40W/m₂백색광을 조사함에 따라 어두운 상태의 대조구에 비하여 급격히 증가하였고, 빛을 계속하여 조사하면 세포내 ATP 함량은 단계적으로 감소하였다. 광수용체 색소 Stentorin 을 포함하고 있는 색소 미립자를 나팔벌레 완전세포로부터 분리하여 이에 ADP와 pi를 가한 혼합물에 빛을 조사하여 ATP가 생성됨을 확인하였다. 나팔벌레 완전세포와 색소미립자주으이 ATP 함량은 변량울에 (fluence rate)의존하였다. 이들 결과로 생명체는 광양자를 ATP로 전이시킬 수 있고, ATP 생성은 나팔벌레 색소미립자의 특성으로 사려된다. The cellular ATP level in Stentor coeruleus jumped above the dark control level when stimulated by 0.5-2 second light pulses (40W/m₂white light). Continued, irradiation fo the cells caused a gradual decline of the cellular ATP level. Pigment granules containing the photoreceptor pigment stentorin isolated from whole cells also exhibited a light-induced ATP synthesis. The ATP level in both whole cells and pigment granules was dependent upon the fluence rate. These results suggest that the organism is capable of tranducing light quanta into ATP and that ATP synthesis is localized in the pigment granule.

세라믹/금속접합재에 대한 접합계면의 응력특이장해석

박영철,허선철,윤두표,강재욱 동아대학교 공과대학부설 생산기술연구소 1997 生産技術硏究所硏究論文集 Vol.2 No.1

Since the ceramic/metal joints at high temperature, the residual stress will develops during when it is cooled from bonding temperature due to remarkable difference of thermal expansion coefficient betwen ceramic and metal. Moreover, the edge of jointed interface makes singular stress field in the ceramic/metal joints and this singular stress field much influences on the strength of joints. In this study, the influence of residual stress, mechnical load and repeat thermal cycle were estimated in the ceramic/metal joints. According to this influence, the change of singular stress field was analyzed. The results are as follow : 1) Strength of joints was evaluated by the stress singularity index λ and the intensity K of singular stress field. 2) the stress singularity index λ and the intensity K of singular stress field also increase as adding temperature of thermal cycle and its number of cycle. 3) In the case of mechanical load, the influence of residual stress reduces since the difference(Δλ) of stress singular index between existence and inexistence of residual stress decreases in proportion to the increasing of tensile load.

저방사화강(JLF-1)의 고온 피로균열진전거동에 관한 연구

박원조,정재욱,허선철,허정원 경상대학교 해양산업연구소 2002 해양산업연구소보 Vol.15 No.-

The objective of this study is to investigate life and fatigue crack propagation in the Reduced Activation Ferritic steel(RAFs) JLF-1. Crack growth rate tests on compact tension specimen of thickness 12mm were conducted by using sinusoidal waveform. Compact tension specimens were used and crack growth rate da/dN and stress intensity factor range ΔK were analyzed concerning to the R value of 0.1, 0.3 and 0.5 In order to find out the value of ΔK, load amplitude constant method was applied by the standard fatigue testing method describes in ASTM E647-95a. The effects of stress ratio and specimen size on the fatigue crack growth propagation for JLF-1 steel were discussed within the Paris law. As the result of this study, fatigue crack growth rate increased with in creasing the load ratio, Consequently, fatigue crack propagation of half size specimen was similar to those of full size specimen at room temperature. Also, there was no difference between base metal and weld metal at room temperature and high temperature.(400℃)

혈관질환 정보관리 시스템

김동익,김덕경,허세호,이병붕,김용신,김은숙,문지영,도영수,신성욱,김동수,김만태,진재욱,김용신 대한혈관외과학회 2002 Vascular Specialist International Vol.18 No.1

As medical technology progresses rapidly, there is a rise in the average age along with the Korean dietary lifestyle becoming more westernized, which leads to an increase in the number of vascular disease patients in Korea. Thus, we need to manage the medical information of a disease systematically in order to diagnose and treat constructively. However, since there has been no standardized method of man agement to date, a great deal of information could not be properly utilized nor studied. Therefore, the departments of Cardiology, Radiology and Neurology of Samsung Seoul Hospital recently got together to develop an information management system called the Vascular Data System. This program was developed to be run on win98 O/S, upper Pentium Ⅲ, and upper 128 MB Memory, and its source code is Dephi 4.0. It was configured for the user to set the configurations as well as do a variety of search and analysis. If this program were to be updated continuously, it may be used extensively as well as in various parts of clinical research activities.

온도 변화에 따른 DW-100 용접재의 기계적특성에 관한 연구

박원조,정재욱,변상열,허선철,유재환 경상대학교 해양산업연구소 2002 해양산업연구소보 Vol.15 No.-

In recent years, the studies of mechanical property of weld materials were one of the most important basic test of our welding indursty. The used specimen in this study is weld metal of DW-100 flux cored wire which is using for flux cored are welding and one type of flux cored wires were used in this test. This paper is based on the quality of the mechanical property of welding material under the different temperture, test temperature of each weld metal is from RT to 900℃ and temperature gap is 100℃ for each weld metal. It is particularly important to assess tensile properties and each specimen was examined using by the following methods; Reduction of area rate, Tensile strength test, and observation of SEM. All tensile tests were performed in accordance with the ASTM standard test method, tension testing of metallic materials (ASTM I-8). This study proves that the mechanical properties of until 400℃ were good as the increasing temperature compare with mechanical properties of RT. As the results of this study, the tensile strength of 300℃ was higher than other weld metals. Also the reduction of area rate was the lowest at 300℃ according to the previous test results. Consequently, this weld metal is a good substitute for the existing welding materials until 400℃ which is used in the development of welding industries today.

A Spectroscopic Study of Hydrogen Bonding between Riboflavin and Salicylic Acid Derivatives

Jae Wook Huh,Byung Sul Yu 대한약학회 1976 약학회지 Vol.20 No.3

Specific association phenomena of riboflavin-2'',3'',4'',5'',-tetraacetate and salicylic acid derivatives, such as salicylic acid, aspirin and salicylamide have been measured by infrared and fluorescence spectroscopy. Salicylic acid and riboflavin tetraacetate form the 1:1 cyclic hydrogen bonded dimer through the imino group and the 2-C carbonyl group of isoalloxazine ring of the latter, and the carbonyl group and carboxylic hydroxyl group of the former. Asprin and riboflavin tetraacetate form the 1:1 cyclic hydrogen bonded dimer by the same mode. Salicylamide forms the 1:1 cyclic hydrogen bonded dimer with riboflavin tetraacetate by using its amide group and carbonyl group. Salicylic acid derivatives are effective quenchers of the fluorescence of riboflavin tetraacetate. It is appeared that salicylamide is the strongest quencher among them. The quenching effect is attributed to the formation of association dimer.

New and improved recombinant hepatitis B vaccine

( Jae-wook Huh ) 대한소아감염학회 1996 Pediatric Infection and Vaccine Vol.3 No.1

Endosaccular Treatment of Very Large and Giant Intracranial Aneurysms with Parent Artery Preservation : Single Center Experience with Long Term Follow-up

Huh, Chae Wook,Lee, Jae Il,Choi, Chang Hwa,Lee, Tae Hong,Choi, Jae Young,Ko, Jun Kyeung The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.4

Objective : Very large (20-25 mm) and giant (${\geq}25mm$) intracranial aneurysms have an extremely poor natural course, and treatment of these aneurysms remains a challenge for endovascular and surgical strategies. This study was undertaken to describe our experiences of endosaccular treatment of very large and giant intracranial aneurysms with parent artery preservation. Methods : From January 2005 to October 2016, twenty-four very large or giant aneurysms in 24 patients were treated by endosaccular coil embolization with parent artery preservation. Nine (37.5%) aneurysms were ruptured and 15 were unruptured, and of these 15, 11 were symptomatic cases and 4 were incidentally discovered. The cohort comprised 17 women and 7 men of mean age 58.5 years (range, 26-82). Mean aneurysm size was 26.0 mm (range, 20-39) and 13 of the 24 aneurysms were giant. Results : Immediate angiographic results were complete occlusion in nine (37.5%) cases, remnant neck in six (25.0%), and remnant sac in nine (37.5%). Overall procedural related morbidity and mortality rates were 12.5% and 4.2%, respectively. Angiographic follow-up was available in 16 patients (66.7%). Mean and median follow-up periods were 27.2 (range, 2-77) and 10.5 months, respectively. In 12 cases (12/16, 75%) stable occlusion was achieved, four cases (4/16, 25%) had recanalized, and two of these were retreated with additional coiling. At clinical follow-up of the nine ruptured cases, three patients (33.3%) achieved a good clinical outcome (Glasgow outcome scale [GOS] score of 4 or 5), two (22.2%) a poor outcome (GOS score of 2 or 3), and four patients (44.4%) expired (GOS 1). On the other hand, of the 15 unruptured cases, 13 patients (86.7%) achieved a good clinical outcome (GOS 4 or 5), one patient a poor outcome (GOS score of 2 or 3), and one patient expired (GOS 1). Conclusion : The present study shows endosaccular treatment of very large or giant intracranial aneurysms with parent artery preservation is both feasible and effective with acceptable morbidity and mortality.

Expression of standard CD44 in human colorectal carcinoma: Association with prognosis

Huh, Jung Wook,Kim, Hyeong Rok,Kim, Young Jin,Lee, Jae Hyuk,Park, Yeon Sun,Cho, Sang Hyuk,Joo, Jae Kyoon Blackwell Publishing Asia 2009 Pathology international Vol.59 No.4

<P>The aim of the present study was to evaluate the expression of standard CD44 (CD44s) in colorectal cancer (CRC), its relationship with clinicopathological characteristics, and its potential prognostic significance. CD44s levels were measured on immunohistochemistry in tumors and surrounding normal mucosa from 74 patients with primary colorectal carcinomas. The patients were followed for a median period of 37 months. Expression of CD44s in primary tumor and surrounding normal mucosa tissues was demonstrated in 100% (74/74) and 37.9% (28/74), respectively. The expression of CD44s in tumors was significantly associated with the depth of invasion (<I>P</I> = 0.034) and lymph node involvement (<I>P</I> = 0.031). A significant difference was observed between the overall survival and level of tumor CD44s expression, especially for stage IV carcinoma (<I>P</I> = 0.038). Multivariate analysis indicated that TNM stage (<I>P</I> = 0.020) and tumor CD44s expression (<I>P</I> = 0.008) were independent predictors of overall survival in adenocarcinomas. CD44s overexpression may be an independent unfavorable prognostic factor for overall survival in advanced CRC, especially stage IV disease. Further investigation, however, is necessary to assess the biological roles of CD44 in CRC, and validate their possible value as novel therapeutic targets.</P>

전기철도 차량 내 변압기의 돌입전류 분석에 관한 연구

허재선(Jae-Sun Huh),신희상(Hee-Sang Shin),강병욱(Byung-Wook Kang),김재철(Jae-Chul Kim) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.11

Neutral section is the facility connecting separate traction power supply system by using insulating device. But power supplied in to the train is stopped and the train moves in coasting state when passing the neutral section. Consequently, driving speed of train is reduced. Further, if the train kept notch-on state get into the neutral section. AC electric railway system and train are be adversely affected. Automatic power switching system in neutral section is one of the best way to improve these problem. But automatic power switching system in neutral section can be caused serious problem. In this paper, these simulated operating characteristics of automatic power switching device and analyzed effect of regenerative source in the train for transformer inrush current.