카드뮴 측적량과 붕어(Carassius auratus) 아가미 조직 변화의 상관성에 관한 연구

배희경,김은경,남성숙,문창규,전성환,나진균,박광식 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.1

Histopathological changes and cadmium accumulations in the gills were investigated in crucian carp (Carassius auratus) exposed to 0, 0.01, 0.1, 0.5 mg/l cadmium (Cd)concentrations for 25 days. After 25 days of exposure, cadmium accumulations increased in each of the different exposure concentrations. Histopathological changes in the gills of curcian carp exposed to cadmium included the acidification of mucous cell, the terminal clubbing of lamellae, the hyperplasia of epitherial cell and the curved of secondary lamellae. The similar histopathological changes were observed once the accumulations of cadmium reached the similar levels found in the present study with the different exposure schemes. Also the acidification of mucous cell in gills appeared when cadmium accumulations reached 5 ㎍/g and more. These results suggested that histopathological changes in the gills, an appearance of mucous cell acidification, be used to estimate the relation between toxic effect and cadmium accumulations in the gills.

중부지역 옥수수 파종기에 따른 생육단계 및 수량성 변화

서종호, 문중경, 정건호, 서민정, 구자환, 박장환, 배환희, 신성휴, 권영업 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

Maize hybrids were planted on April 1, April 25, May 20 and June 15 in 2012, 2013 at the experimental paddy and upland fields in Suwon city , respectively to know changes of growth stage and yield according to different planting time. Maize planting on April 1 was not recommended because total growing days at planting on April 1 was not different with that at planting on April 25 due to many days from planting to emergence over 20 days at planting on April 1. Total growing days were not much different among three planting time after April 25 because days from silking to maturity was lengthened though days from planting to silking was shortened at later planting time. Stalk weight was decreased as planting time was delayed, particularly at planting times after May 20 at paddy field by excess water injury during early growth stage. But, grain yield was not low as in May and June. It is needed to introduce early maturity maize variety as Yanganok at late planting for higher grain yield and enough time for soil preparation for next winter crops

A case of erosive vitreoretinopathy

Seong Eun Kyung,Moo Hwan Chang,Jun Young Ji 대한안과학회 2002 Korean Journal of Ophthalmology Vol.16 No.1

Hereditary vitreoretinopathies are potentially blinding inherited disorders characterized by an abnormal-appearing vitreous gel and associated retinal changes. Four of these disorders, Stickler’s syndrome, Wagner’s disease, erosive vitreoretinopathy, and Goldmann-Favre syndrome, exhibit marked syneresis of the vitreous gel. Erosive vitreoretinopathy has associated retinal pigment epithelial changes, poor night vision, visual field defects, and abnormal electroretinographic findings; symptoms not found in Stickler’s syndrome. A 36-year-old man with progressive visual loss and a visual field defect had no systemic disease. His vitreous cavity was liquefied. Vitreous strands and a cataract were found in both eyes. Pronounced RPE degeneration was found superotemporally in both eyes and a bullous rhegmatogenous retinal detachment in the left eye accompanied two retinal tears. His visual field showed a ring scotoma in both eyes and the ERG finding was abnormal. We report one case of erosive vitreoretinopathy with retinal pigment epithelial changes, rhegmatogenous retinal detachment, visual field defects, abnormal electroretinographic findings, marked vitreous syneresis and cataract. These symptoms are distinct from previously described entities.

난류 모델별 수치해석을 이용한 업윈드형 소형 풍력터빈의 성능 연구

유창환 ( Chang-hwan Yu ),김성환 ( Seong-hwan Kim ) 조선대학교 공학기술연구원 2020 공학기술논문지 Vol.13 No.4

In the field of renewable energy, there is growing interest in wind energy to cope with climate change. Research is needed on small residential facilities or stand-alone small wind turbines for microgrid power generation. This study is for commercialization of a small horizontal wind turbine of a 2,600 mm diameter upwind type and is a thesis for a design and performance check on performance. A blade was designed and flow analysis was performed with ANSYS CFX to verify the performance of the generator. As analysis conditions, numerical analysis was performed on the κ-ε, κ-ω , and SST turbulence models, and the torque for each condition was calculated to determine the output from the wind turbine. From the results of the numerical analysis, the maximum torque was calculated in the order of SST, κ-ω, andκ-εand the output was calculated in the order of SST, κ-ω, and κ-ε. The coefficient of power value was calculated as 0.225 for κ-ε, 0.236 forκ-ω, and 0.240 for SST. From the results of the numerical analysis, it was confirmed that all three conditions provided 700 W class output at a 10 ㎧ wind speed condition.

Ischemia-Related Changes in Galanin Expression in the Dentate Hilar Region after Transient Forebrain Ischemia in Gerbils

LEE, Hyeon Yong,HWANG, In Koo,KIM, Dae Ho,KIM, Jung Hwa,KIM, Chang Ho,LIM, Beong Ou,KANG, Tae-Cheon,BANG, Kyung Hwan,SEONG, Nak Sul,LEE, Hak Ju,KIM, Jong Dai,WON, Moo Ho Japanese Association for Laboratory Animal Science 2005 EXPERIMENTAL ANIMALS Vol.54 No.1

<P>Although galanin (GAL) protects hippocampal neurons from ischemic damage, no study has examined ischemia-related changes in endogenous GAL in the hippocampal dentate gyrus. We investigated the chronological changes of GAL, well-known as the potassium channel opener, expression in the dentate gyrus at various times after 5 min of transient forebrain ischemia in gerbils. A few GAL-immunoreactive (IR) neurons were found in the polymorphic layer of the sham-operated group. Three hours after ischemia-reperfusion, the pattern of GAL immunoreactivity was similar to that of the sham-operated group and the number of GAL-IR neurons and immunoreactivity were highest 12 h after ischemic insult. At this time, GAL-IR neurons in the polymorphic layer showed strong GAL immunoreactivity. Thereafter, GAL-IR neurons and immunoreactivity significantly decreased in the dentate hilar region. Four days after ischemic insult, GAL-IR neurons were not detectable. In addition, the results of a Western blot study showed a pattern of GAL expression similar to the immunohistochemical changes. GAL protein content also was highest 12 h after ischemia. In conclusion, the increased expression of endogenous GAL in the dentate gyrus after ischemia is related to response to the ischemic damage.</P>

우리나라 지역 직업성질환 감시체계의 현황과 전망

임종한,장성실,김성아,문재동,채창호,홍윤철,김수영,김진석,김영욱,한상환,이혜숙,원종욱,송동빈,하은희,강성규 대한산업의학회 2001 대한직업환경의학회지 Vol.13 No.2

기존의 특수건강진단과 작업환경측정을 통한 직업병 관리가 진폐증, 소음성난청 등의 소수 특정질환에 국한되고 실제 직업병 발생 규모 파악이나 신종 직업병의 발견에 한계를 보인다는 사실은 산업의학전문가들 사이에서도 공감을 이루고 있다. 미국과 영국 등에서의 직업성질환 감시체계에 대한 경험은 우리 나라의 직업성질환 감시체계 구축에도 새로운 자극제가 되면서, 1998년이후 인천, 대전, 여천, 구미, 부울경 지역에서 지역 직업성질환감시체계를 산업보건관리의 중요한 시스템으로 구축하려는 노력이 확산되고 있다. 새로이 구축되어지는 이들 지역 직업성질환 감시체계는 감시하고자 하는 대상질환, 활용 가능한 인적자원 및 자료원, 지역 의료체계의 특수성 등에 따라서 목적과 방법을 달리하면서 독특한 형태로 발전을 하고 있다. 각 지역단위 감시체계들이 그 상황에 맞게 독특한 목적과 전략들을 발전 시키면서도, 향후 발전할 국가적인 차원의 직업성질환 감시체계 구축을 위하여 직업성질환 감시의 기본 전략 등을 공유하는 등의 노력이 필요하다. 환례 정의 및 기본적인 등록 서식의 공유, 직업성질환 감시 자료원의 발굴, 공동의 정보 네트워크 및 직업성질환 감시 데이터베이스 구축 등 직업성질환 감시활동을 지원하기 위한 여러 기초 인프라 구축에 힘을 모아야 할 것이다. 우리 나라에서 직업성질환 감시체계를 성공적으로 구축하기 위해서는 수집된 자료의 질 관리를 위한 직업성질환 감시의 원칙 제정과 감시 전략의 공유 등이 필요하며, 전국적인 직업성질환 감시체계의 하부구조라고 할 수 있는 지역감시체계의 기초 토대 마련과 강화작업이 절실하게 필요하다.

췌장가성낭종에 대한 임상적 고찰

서종권,장정환,김성환,김정용,민영돈,김권천,김종안 朝鮮大學校 附設 醫學硏究所 1996 The Medical Journal of Chosun University Vol.21 No.1

For the purpose of finding the changing patterns of the status and management of the patient with pancreatic pseudocyst who were treated in same hospital according to the time sequence, the authors reviewed 29 patients' charts with pancreatic pseudocyst treated at department of Surgery, Chosun University Hospital during 11 years from Jan. 1984 to Dec. 1994 comparing with those of the previous 24 patients treated from Jan. 1974 to Dec. 1983 that was reported at the Journal of Korea Surgical Society, 1985. The following results were obtained: 1. The age and sex distribution were not changed. The male and female ratio was 2.2~2.4:1 and the most prevalent age group was fourth decade and fifth decade. 2. The pancreatitis was the main etiologic disease and it was more frequent than previous report. That can be probably attributed to the increasing of alcohol intake. 3. The pancreatic body was the most affective site. 4. The common symptoms and signs were abdominal pain and tenderness(93.1%), upper abdominal palpable mass(48.3%), and anorexia, nausea and vomiting(44.8%). That was not changed with previous report. 5. The duration of symptoms to diagnosis were usually 3~4 weeks and 5~6 weeks. 6. The most common laboratory finding was amy1asemia(72.4%). 7. The preoperative complications were pleural effusion (48.3%), infected cyst(17.2%) and rupture of cyst(10.3%). 8. We could obtain good outcomes in the 7 patients(25.9%) treated conservatively. The surgical treatment, external drainage, internal drainage and excision, were done in 21 patients according to the patients status. 9. There were total 11 cases(52.4%) postoperative complications in all operation patients. That rate was increased than before. However it does not mean true increase because of poor preoperative condition of the patients. 10. The time interval between diagnosis and operation was 1~3weeks(47.6%) and 3~6weeks(28.6%). The proper operation time should be taken case-byUcase. In conclusion, the last decade has witnessed no additional changes in diagnosing and curing pancreatic pseudocyst other than the following two. The disease is increasingly cause by pancreatitis, Particularly alcoholic pancreatitis and it can be more effectively dealt with by the conservative treatment. Nevertheless much remains to be discussed on the adequate time and therapy in curing pancreatic pseudocyst. What matters here is to develops more specified methods for each patient taking into consideration on the nature of disease.

Effects of aerosol on evaporation, freezing and precipitation in a multiple cloud system

Lee, Seoung Soo,Kim, Byung-Gon,Yum, Seong Soo,Seo, Kyong-Hwan,Jung, Chang-Hoon,Um, Jun Shik,Li, Zhanqing,Hong, JinKyu,Chang, Ki-Ho,Jeong, Jin-Yim Springer-Verlag 2017 Climate dynamics Vol.48 No.3

<P>Aerosol effects on clouds and precipitation account for a large portion of uncertainties in the prediction of the future course of global hydrologic circulations and climate. As a process of a better understanding of interactions between aerosol, clouds and precipitation, simulations are performed for a mixed-phase convective multiple-cloud system over the tropics. Studies on single-cloud systems have shown that aerosol-induced increases in freezing, associated increases in parcel buoyancy and thus the intensity of clouds (or updrafts) are a main mechanism which controls aerosol-cloud-precipitation interactions in convective clouds. However, in the multiple-cloud system that plays much more important roles in global hydrologic circulations and thus climate than single-cloud systems, aerosol effects on condensation play the most important role in aerosol-induced changes in the intensity of clouds and the effects on freezing play a negligible role in those changes. Aerosol-induced enhancement in evaporation intensifies gust fronts and increases the number of subsequently developing clouds, which leads to the substantial increases in condensation and associated intensity of convection. Although aerosol-induced enhancement in freezing takes part in the increases in condensation by inducing stronger convergence around cloud bottom, the increases in condensation are similar to one order of magnitude larger than those in freezing. It is found that while aerosol-induced increases in freezing create intermittent extremely heavy precipitation, aerosol-induced increases in evaporation enhance light and medium precipitation in the multiple-cloud system here. This increase in light and medium precipitation makes it possible that cumulative precipitation increases with increasing aerosol concentration, although the increase is small. It is interesting that the altitude of the maximum of the time- and domain-averaged hydrometeor mass densities is quite robust to increases in aerosol concentration. This is because locations of gust fronts and homogeneous freezing do not vary significantly with changing aerosol concentration and this outweighs aerosol effects on hydrometeor size.</P>

건식 미분 분급장치의 특성에 관한 연구

장경환,김성종,정경락 全北大學校 1990 論文集 Vol.32 No.-

A new air classifier with cut size smaller than about 10㎛, which allowed rapid classification to avoid the disturbance of particles reagglomeration, was designed and manufactured. The characteristics of the air classifier for fine powders was experimentally investigated. The results of the experimentation could be summerized as follows. 1) As the velocity of laden air was increased, the entrainment of fine particles into the coarse side was impressed.. 2) When the velocity of clean air was equal to the velocity of laden air, the sharpness index was good. 3) By sucking a portion of clean air into the fine side, the entraintment of fine particles into the coarse side was effectively suppressed. 4) The cut size and the classification performance were not affected by feed concentration up to at least 0.3kg/㎥.

개에서 급성 동량성 혈액희석 하에 Esmolol을 이용한 유도저혈압이 심혈관계 및 전신 산소균형에 미치는 영향

장성호,도상환 대한마취과학회 1998 Korean Journal of Anesthesiology Vol.35 No.4

Background : Acute normovolemic hemodilution (ANH) is one of the methods of autologous transfusion drawing much attention recently. It is economical and easy to apply to many surgeries requiring multiple transfusions. When used as a drug for induced hypotension, esmolol can avoid many drawbacks of sodium nitroprusside and reduce the amount of intraoperative bleeding with better operative field. Considering recent trend of combining ANH and induced hypotension to increase the success rate of autotransfusion, esmolol-induced hypotension with ANH will be used more frequently in the future. However, tissue oxygen balance may be in danger because of decreased tissue perfusion pressure by induced hypotension and reduced arterial oxygen content by ANH. Thus it is necessary to evaluate effects of induced hypotension combined with ANH on cardiovascular system and systemic oxygen balance. Methods : In 8 mongrel dogs anesthetized with N2O-O2-enflurane and paralyzed with vecuronium, ANH was performed up to half of initial level of hemoglobin with isovolemic pentastarch infusion, and then mean arterial pressure (MAP) was lowered by 30% of the initial value by intravenous administration of esmolol. Various hemodynamic parameters were measured before and after ANH and 15, 30, 60 and 90 minutes after induction of hypotension and 30 minutes after the end of hypotension. Results : Heart rate began to decrease after ANH and showed significant decrease at 60 and 90 minutes after hypotension compared with initial value. Central venous pressure increased significantly after ANH and hypotension. Pulmonary arterial pressure showed significant increase at 15 and 90 minutes after hypotension. Cardiac output was increased markedly by ANH but began to decrease after hypotension and showed significant decrease at 60 minutes after hypotension. Systemic vascular resistance showed significant decrease after ANH, 15 minutes after hypotension and 30 minutes after discontinuation of esmolol. Pulmonary capillary wedge pressure and pulmonary vascular resistance showed no significant change. Oxygen flux was decreased markedly by esmolol but recovered after discontinuation of esmolol. Oxygen consumption was maintained throughout the study. Oxygen extraction ratio was increased dly after hypotension. There were no acidemia and hypoxemia throughout the study. Conclusion : In conclusion, the results of this study suggest that tissue oxygen delivery might be decreased by anemia but that systemic oxygen balance might be preserved by ANH and induced hypotension within the range used in this study. (Korean J Anesthesiol 1998; 35: 607∼617)