용접 근로자의 혈액 및 요중 망간 농도

현대우,안선희,김강윤,최호춘 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.4

Blood and urine samples were taken from 447 welders exposed to manganese containing welding fumes and 127 office workers not exposed to welding fumes as a control. The air samples were analyzed by flame atomic absorption spectrophotometer(Varian 30A, Australia), and blood and urine samples were analyzed by flameless atomic absorption spectrophotometer(Z-8100, Hitachi, Japan). Data were evaluated in accordance with type of industry, smoking habits, and work duration. The results obtained were as follows: 1. The limit of detection(LOD) levels of manganese in blood and urine were 0.11㎍/100㎖ and 0.14㎍/ι, respectively. Our results of manganese concentration were shown within ±2 standard deviation which was the upper and lower warning limit(UWL or LWL) on quality control chart. 2. The airborne concentrations of manganese in welding workplaces were 0.067㎎/㎥ showing differences by type of industry; 0.017㎎/㎥ in automobile assembly and manufacturing industries, 0.084㎎/㎥ in steel heavy industries and 0.180㎎/㎥ in shipyards. 3. The blood manganese concentrations showed differences by type of industry showing the highest values of 1.70㎍/100㎖ in shipyards, 1.24㎍/100㎖ in automobile assembly and manufacturing industries and 1.111㎍/100㎖ in steel heavy industries. Urinary manganese concentration corrected by urinary creatinine concentrations was 0.34㎍/g creatinine in automobile assembly and manufacturing industries, 0.43㎍/g creatinine in steel heavy industries and 0.48㎍/g creatinine in shipyards. There were no difference urinary manganese concentrations by type of industry. 4. The overall blood manganese concentration was 1.26㎍/100㎖, and urinary manganese concentration was 0.35㎍/g creatinine in welders. In contrast to these values, blood and urinary manganese concentrations were lower in control group showing 0.73㎍/100㎖,, and 0.28㎍/g creatinine, respectively. 5. Smoking habits did not seem to affect on blood and urinary manganese concentrations both in welders and office workers. 6. Blood manganese concentrations were significantly higher in welder who had worked longer than 10 years than in welder who had worked less than 10 years. 7. The blood manganese concentrations were significantly correlated to airborne manganese concentrations(r=0.318, n=64), work duration(r=0.425, n=538), and cumulative exposure indices(CEI) (r=0.354, n=64).

대량 출혈을 유발한 공장게실 1예

전정현,이선영,이나란히,신정은,주미순,정성애,한호성,유권 梨花女子大學校 醫科大學 醫科學硏究所 2001 EMJ (Ewha medical journal) Vol.24 No.1

A case of massive intestinal bleeding from jejunal diverticulum is describe. A 62-year-old man was refered to our hospital because of melena and anemia. After admission, he showed massive hematochezia with unstable vital sign. Esophagogastroduodenocopy and colonoscopy, selective abdominal angiography, and RBC bleeding scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. The examination of small bowel with methylcellulose showed multiple small jejunal diverticuli and a large diverticulum. Resection of the involved portion of jejunum was performed. On pathological examination, two mucosal loss lesions were detected, but ulcer or arteriovenous malformation were not seen in the resected jejunal diverticulum. The patient showed no more intestinal bleeding after operation. Although jejunal diverticuli are rare, the careful search for this complication in a patient with intestinal bleding is important.

Phase-Type 분포를 이용한 보증서비스 비용 분석

김호균,백천현,조형수 한국경영과학회 2000 韓國經營科學會誌 Vol.25 No.3

We consider the question of servicing warranties for repairable items. During the warranty period, each time an item fails the manufacturer has the obligation to restore the item to operational condition either by repairing the item or by replacing it by a new item. For products with phase-type lifetime distributions where the phases represent the condition of the item. We develop algorithms to determine the expected cost of servicing a warranty and use it in making the repair/replacement decision. Illustrative numerical examples are presented.

木花 收量構成形質의 遺傳分析

崔周浩,李信雨,全鉉植,李喆浩 진주산업대학교 농업기술연구소 2005 農業技術硏究所報 Vol.18 No.-

2001년부터 2003년까지 木花 10개 品種을 二面交配하여 얻은 F_(1), F_(2) 45개 組合을 재료로 生育形質의 交配集團에 따른 遺傳分析한 結果를 요약하면 다음과 같다. 1. 각 형질에 대한 분산분석 결과는 전형질에서 고도의 유의성을 나타내었다. 2. 유전자의 상가적효과의 값은 우성효과의 값보다 높게 나타났고, F_(1)세대의 株當□數에서 가장 높았으며, 百粒重은 F_(2)세대에서 오히려 높아 세대간에는 일정한 경향을 보이지 않았다. 3. 유전력은 섬유장을 제외한 전 형질에서 0,80이상으로 평가되었고, 그 중 섬도는 F_(1)세대에서 0.97로 조사된 형질 중 가장 높았다. The quantitative inheritance of some yield characters in Gosyium spp was carried out by means of a 10×10 diallel cross. This study was genetically analyzed through diallel cross population among 10 different cultivars of cotton (Gosyium spp) at an experimental field in Jinju National University. According to research from April 2001 to December 2003, the results of genetic analysis were summarized as follow: 1. The high significance was observed from the genetic variance analysis in the all examined characters. 2. In the component of genetic variance analysis, additive effects were relatively higher than dominant effects. The number of boll in F_(1) generation was higher than F_(2), whereas no significant difference was seen in the dominance degree and gene arrangement between F_(1) and F_(2) generations because 100 seeds weight in F_(2) generation was much higher F_(1). 3. The progeny of F_(1) heritability was found to exceed a suggested minimum of 0.80 excepting fiber length. The heritability of F_(1) in fiber fineness was 0.97 relatively higher than other all examined characters.

활성탄관에 포집된 2MEA와 2EEA의 에스테르화가 2MEA와 2EEA 분석에 미치는 영향

김현욱,김강윤,최호춘 한국산업위생학회 2003 한국산업보건학회지 Vol.13 No.1

This study was performed to find an appropriate desorbing solution for 2MEA and 2EEA collected activated charcoal. The desorbing solution should be transesterification-free and have reliable desorption efficiency. Anumber of desorbing solutions were tested against CS2 and MeOH/ methylene chloride(5/95, v/v, 5MeOH) which were normally used as desorbing solutions. Transesterfication of 2MEA and 2EEA on dry charcoal by 5MeOH was also verified. A GC/MSD was used for verification of transesterification. Desorption effciencies of several desorbing solutions were measured by GC/FID, As desorbing solutions, CS2, 5MeOH, DMF/CS2(1/99, v/v, 1DMF), and DMF/cs2(3/97,v/v, 3DMF)were selected. Desorption effciencies of 2MEA and 2EEA were 97.3% and 99.2% by 5MeOH, respectively, and 100.8% and 101.4% by 3DMF, respectively. No significant difference between 5MeOH and 3DMF was found for both 2MEA and 2EEA(p〈0.05), Transesterification of 2MEA and 2EEA on dry charcoal at≥10 ppm was confirmed when 5MeOH was used as the desorbing solution, However, when 3DMF was used, no transestserification of 2MEA and 2MEEA on dry charcoal was found. This study found that 3DMF (DMF/CS@, 3/97, v/v)was the desorbing solvent of choice for 2MEA and 2EEA collected on coconut shell charcoal tube With the solutiom, no transesterification was found with nearly 100% desorption efficiency.

동종 조혈모세포이식 후 발생한 크립토콕쿠스 척추염 1예

고윤호,임동준,이성수,조유경,이동건,최정현,김유진,민창기,김동욱,박정미,김춘추,신완식 대한감염학회 2001 감염 Vol.33 No.4

Skeletal cryptococcosis is an uncommon infection. Cryptococcus is a common cause of meningitis and infects 7∼10% of patients with AIDS. As well as AIDS, the infection may be seen in association with leukemia, lymphoma, Hodgkin's disease, sarcoidosis, tuberculosis and diabetes, also in patients on steroid medication. But there is no case report of skeletal cryptococcosis following allogeneic hematopoietic stem cell transplantation. A 40-year-old woman was admitted to the hospital because of low back pain. She had chronic myelogenous leukemia for 2 years and underwent allogeneic hematopoietic stem cell transplantation 8 months ago. She have been treated with steroid and cyclosporine orally because of chronic graft versus host disease. On examination she was afebrile and had posterior lower lumbar tenderness. But, she had no reduced strength of low extremities. Open biopsy was underwent. Histology demonstrated budding, round-to-oval, refractile yeast-like organisms within debris. The results of a lumbar puncture were unremarkable and cerebrospinal fluid culture failed to grow bacteria and yeast. The patient was treated with amphotericin B (1 gram) and AmBisome□ (2.8 gram) over 6 weeks. Three months after cessation of therapy, the patient was doing well.(Korean J Infect Dis 33:298∼301, 2001)

진동 감쇠를 위한 MR Damper 개발

김현식,전종균,장현호 선문대학교ㆍ중소기업기술지원연구소 2000 선문공대 연구/기술 논문집 Vol.5 No.1

본 논문에서는 교량 및 건측구조물의 진동문제를 보완하기 위한 방법으로서 자성유체를 이용한 MR 댐퍼를 연구하였다. 또한 자성유체의 특성과 성능에 대하여 연구하였으며, 설계도면을 기초로 MR댐퍼를 제작하였다. 만능재료 시험기를 통해서 주파수와 전류 및 변위를 단계적으로 변화시켜가며 성능실험을 반복적으로 수행하였다. In this paper, magneto rheological damper was studied to solve vibration problems of bridge and structures. Also, characteristics and efffectiveness of magnetic fluid was investigated. MR damper was manufactured on the asis of design drawing. To investigate the efficacy of magneto rheological phenomenon, experiments were performed on sequencies, displacements and electric currents using Universal Testing Machine(UTM).

칠절봉 신갈나무(Quercus mongolica)림의 군락구조와 토양환경

이호준,배병호,전영문,정흥락,홍문표,김용옥,길지현 建國大學校基礎科學硏究所 1998 理學論集 Vol.23 No.-

칠절봉 신갈나무림의 군락구조와 토양환경과의 관계를 파악하기 위해 식물사회학적 조사와 토양 환경을 분석하였다. 조사지역의 신갈나무림은 신갈나무군락, 철쭉꽃하위군, 큰개별꽃하위군으로 구분되었으며, 철쭉꽃하위군과 큰개별꽃하위군에서의 방형구당 평균출현종수는 각각 30종(24∼46종), 43종(31∼52종) 이었다. 피복지수치에 의한 계층별 우점순위는 교목층에서 신갈나무(6750.0), 아교목층에서 당단풍(2364.0) 관목층에서 철쭉꽃(988.5), 초본층에서 쌀새(1040.5)가 가장 높게 나타났다. 신갈 나무림의 DBH 분포는 2∼10㎝ 범위의 소경목이 전체의 29.7%를 차지하였으며 전체적으로 정규분포를 나타내어 교란 후 재생과정에 있는 것으로 조사되었다. 또한 후계목의 발달로 인한 극상상태로의 천이가 가능할 것으로 조사되었다. 전반적인 토양환경은 두 하위군 간에 뚜렷한 차이가 없었으며, 큰개별꽃하위군이 철쭉꽃하위군에 비하여 다소 양호한 것으로 조사되었다. 환경구배분석에서 까치박달, 물푸레나무, 함박꽃나무 등은 습한 곳에 분포하고 철쭉꽃, 전나무, 국수나무 등은 건조한 곳에 분포하는 것으로 나타났다. A relationship between the community structure composition and soil environmental factors of the Quercus mongolica forest on Mt. Chiljelbong was investigated from June 1996 to August 1997. The Q. mongolica community was classified into two subcommunity of Rhododendron schlippenbachii and Pseudostellaria palibiniana. The 30(24-46) species per quadrat were appeared in R. schlippenbachii subcommunity and 43(31-52)species in P. palibiniana subcommunity. The dominant sequences on each stratum determined by the coverage index showed that Q. mongolica was the most dominant in tree-1 layer with 6750.0, Acer pseudo-sieboldianum in tree-2 layer with 2364.0, R. schlippenbachii in shrub layer with 988.5, and Melica onoei in herb layer with 1040.5 value. The value of diameter breast height(DBH) showed a normal distribution displaying a highest value in the range of 2∼10㎝(29.7%) in Q. mongolica forest and it was investigated being at restoration phase after disturbance. It also was investigated that the succession to climax state would be possible due to growth of successive tree. Overall, which the soil conditions make little difference between two subcommunities, P. palibiniana subcommunity was favorable than those of R. schlippenbachii subcommunity. It was shown that in an environmental gradient analysis, Carpinus cordata, Fraxinus rhynchophylla, and Magnolia sieboldii were distributed in a mesic area, but R. schlippenbachii, Abies holophylla, and Stepanandra incisa in a xeric area.

급성하벽심근경색에서 전흉부유도 ST절 하강의 의의

정병천,배호상,곽동훈,김영태,배용학,황종현,임현주,류재근,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : 급성하벽심근경색증 환자에서 심전도상 흔히 동반되는 전흉부유도 ST절 하강의 의의를 알아보았다. 방법 : 심근경색후 24시간에서 48시간에 얻은 심전도를 기준으로 52명의 급성하벽심근경색증 환자를 전흉부유도에서 ST절의 하강이 있는 군과 없는 군으로 나누었으며 심도자, 관상동맥조영술, 심초음파도 및 방사성 핵종을 이용한 좌심구혈율 측정 등을 시행하였다. 결과 : 1) 좌심실확장기말압은 전흉부유도에서 ST절의 하강이 있는 경우에서 16.9±5.33mmHg로 없는 경우의 11.0±4.02mmHg보다 유의하게 높았다(p<0.05). 그러나 운동량 및 좌심구혈을은 흥부 유도상 ST절의 하강이 있는 경우 7.6±3.0 METs 및 53.9±9.1%로 없는 경우의 9.1±2.7 METs 및 54.6±9.5%보다 낮았으나 통계적 유의성은 없었다(p=0.180, p=0.823). 2) 관상동맥조영술상 전흉부 ST절의 하강이 동반된 군에서는 유의한 좌전하행지나 좌회선지의 협착이 있는 경우가 60.9% 및 57.9%로 ST절의 하강이 없는 군에서의 34.5% 및 7.7%와 비교해 좌관상동맥에 협착이 동반된 경우가 많았다(p=0.050, p=0.001). 3) 관상동맥조영술상 세 혈관질환의 빈도는 흉부유도상 ST절의 하강을 보인 23예에서 10예로 ST절 하강이 없었던 29예중 2예에 비하여 유의하게 많았고(P=0.007), 단 혈관질환의 빈도는 ST절의 하강을 보인 군에서 23예중 5예로 ST절 하강이 없었던 29예중 17예에 비하여 유의하게 적었다(P=0.002). 두 혈관질환의 경우에는 각각 8예와 10예로 양군간에 유의한 차이가 없었다. 4) 흉부유도상 ST절 하강의 빈도는 단 혈관질환 22예 중 5예에서, 두 혈관질환 18예중 8예, 세 혈관질환 12예 중 10예에서 관찰되어 협착이 있는 관상동맥의 수가 많을수록 ST절의 하강이 나타나는 빈도가 많음을 보였다(p=0.00308). 그러나 흉부유도상 나타난 ST절의 하강을 모두 합하여 구한 ST절 하강의 합은 협착이 있는 관상동맥의 수와 통계적인 유의성이 없었다. 5) 심초음파도상 좌심실 하벽의 벽운동은 ST절 하강을 보인 군에서는 akinesia가 83.3%, hypokinesia가 11.1%, 정상 벽운동이 5.6%로, ST절 하강이 없었던 군에서의 dyskinesia가 3.6%, akinesia가 39.3%, hypokinesia가 25.0%, 정상 벽운동이 32.1%와 비교하여 ST절의 하강이 있는 군에서 유의하게 벽운동의 장애가 빈번함을 보였다(p=0.03891). 그러나 좌심실전벽, 측벽 및 중격부위에서는 유의한 벽운동의 차이가 없었다. 결론 : 급성하벽심근경색증 환자의 전흉부유도에서 ST절의 하강이 동반되는 경우 다혈관 질환의 가능성이 높으며 좌심실확장기말압이 상승되었고 운동능력은 감소되어 있었다. 또한 심초음파도상 좌심실하벽의 벽운동장애도 심하였다. 따라서 전흉부 ST절의 하강을 동반한 급성하벽심근경색증 환자는 전흉부유도에 ST절 하강이 없는 경우보다 예후가 불량할 것으로 생각되며, 보다 적극적인 치료가 필요할 것으로 생각된다. The purpose of this study was to determine the significance of precordial ST segment depression appearing during acute inferior myocardial infarction and to assess the correlation of that with angiographic finding. 52 patients were allocated into two groups based on the existence of precordial ST segment depression : 23 patients with ST segment depression and 29 patients without ST segment depression. The extent of coronary artery disease as well as the prevalence of significant stenosis (≥70%) in left anterior descending artery were more frequent in patients showing precordial ST segment depression than in patients not showing them (p=0.050) and the result were similar in cases of left circumplex artery (p=0.001). On echocrdiographic examination of left ventricular (LV) wall motion, it showed more severely decreased inferior LV wall motion in patients showing precordial ST segment depression than in patients not showing them (p=0.03891) even though the other segment of LV wall motion didn't show the statistical difference between both groups. The other cardiac parameters such as LVEDP, exercise amount (METs) and ejection fraction were tend to showing bad profile in patients with precordial ST segment depression. From the above results, we could deduce that patients with precordial ST segment depression have relatively large infarction or concomitant left coronary artery disease, so they need more caution and intensive theraphy.

SBA-15에 담지된 전이 금속 촉매상에서 p-Xylene의 불균일 액상 산화반응

김영호,손용배,류재춘,양현수,전기원,박상언 한국공업화학회 2004 공업화학 Vol.15 No.1

화학적으로 개조된 SBA-15 실리카 위에 활성 전이 금속 종들(Co, Mn, Ni, Fe, or Cu)이 담지된 불균일 촉매를 제조하였다. 제도된 촉매상에서 p-xylene의 불균일 액상 산화반응이 손쉬운 촉매 분리를 위한 불균일 공정의 개발 가능성을 검토하기 위하여 수행되었다. SBA-15 위에 결합된 Co 종(Co-SBA-15)은 다른 전이 금속 종들보다 대응하는 방향족 카르복실산으로의 산화 반응에 가장 효과적인 것으로 나타냈다. 더 나아가 Co-SBA-15 촉매상에서 반응시간(0.5~9 h), 반응온도(130~190 ℃), 전압(10~25 atm) 및 산소 분압(1~9 atm)과 같은 반응 변수의 영향을 연구하였다. 높은 전환율에서 고체 생성물인 terephthalic acid의 형성은 매우 낮고 그때 활성점 위에서 고체 생성물의 쌓임으로 인해 촉매가 쉽게 비활성화 되었을지라도, p-toluic acid로는 고려할만한 선택성이 관찰되었다. p-Toluic acid 및 terephthalic acid를 향한 중간 산화 생성물들의 선택성을 기초로 추정된 반응 경로는 균일 Co/Mn 촉매 반응계에서와 비교하여 거의 같다. 이것은 Co-SBA-15 촉매가 균일 촉매적 행동을 하는 불균일 촉매이고 고체 생성물을 생성하지 않는 탄화수소들의 액상 산화반응을 위하여 잘 적용될 수 있을 것임을 시사한다. Active transition metal species (Co, Mn, Ni, Fe, or Cu) supported on a chemically modified SBA015 silica were prepared as heterogeneous catalysts. The heterogeneous liquid phase oxidation of p-xylene on the prepared catalysts was carried out to investigate the possibility of the development of heterogeneous process for easier catalyst separation.The Co species bound on the SBA-15(Co-SBA-15) was found to be the most effective for the oxidation to corresponding aromatic carboxylic acids than the other transition metal species. In addition, the effects of reaction variables such as reaction time(0.5∼9h), reaction temperature (130∼190℃), total pressure (10∼25 atm) and the partial pressure of oxygen (1-9 atm) were studied on the Co-SBA-15 catalyst. At high levels of conversion, the considerable catalytic activities to p-toluic acid were observed, even though formation of terephthalic acid, an solid product, was very low and then the catalyst was easily deactivated due to build--up of solid products on active sites. The proposed reaction network based on the selectivities of intermediate oxidation products for p-toluic and terephthalic acid was similar to that on the homogeneous Co-Mn catalytic reaction system. This indicates that the Co-SBA-15 catalyst is a heterogeneous catalyst which can behave like a homogeneous catalyst and may be well applied to the liquid phase oridation of hydrocarbons without formation of solid products.