• Title/Summary/Keyword: 흡입과정

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DNA damages with Fpg/Endo Ⅲ FLARE Assay in cynomolgus monkeys exposed to stainless steel welding fume (용접흄 흡입노출 영장류에서 Fpg/Endo Ⅲ FLARE Assay를 이용한 DNA 손상 및 회복)

  • Rim, Kyung Taek;Kim, Soo Jin;Chung, Yong Hyun;Kim, Hyeon Yeong;Maeng, Seung Hee;Yu, Il Je
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.17 no.4
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    • pp.272-281
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    • 2007
  • 선박제조업을 비롯한 운송업 및 건축업 등의 다양한 분야에서 용접기술이 이용되어 옴에 따라 용접근로자들에 대한 산업보건학적 관심이 높아지고 있다. 노출정도가 다양하기는 하지만 용접흄은 6가 크롬을 비롯한 금속화합물과 유해가스, 화학물질 등을 복합적으로 포함하고 있는 스테인레스 스틸 용접흄에 대한 유전독성영향을 평가하기 위하여 흡입챔버를 이용, 실험동물인 영장류에 스테인레스 스틸 용접흄을 노출시키고 혈액 내 lymphocytes에 생성된 용접흄 노출농도 및 시간별 DNA 손상정도 및 그 회복효소를 측정함으로써, 유해성이 완전하게 확인되지 않은 용접흄에 노출되어 나타날 수 있는 암을 비롯한 심각한 건강영향을 예방하기 위한 각 지표들을 찾아 그 유용성을 비교하고자 하였다. 영장류를 노출시키기 위해 robotic arm을 장치한 영장류 흡입노출 시스템을 개발하였으며, 이 노출 시스템을 이용하여 수컷 영장류 6마리에 대해 용접흄 노출시험을 실시하였는데 실험군은 대조군 2, 저농도 ($31mg/m^3$) 노출군 2, 고농도 ($63mg/m^3$) 노출군 2마리로 구성하였고, 1일 2시간씩 일주일에 5일 동안 용접흄에 노출시켰다. 노출 농도는 지속적으로 모니터링 하였고, 노출과정 중에 영장류의 혈액을 채취하여 lymphocytes를 분리, 단세포 DNA 손상을 선별하기 위해 DNA 손상회복 효소인 E. coli formamidopyrimidine-DNA glycosylase (Fpg)와 endonuclease Ⅲ (Thymine Glycol-DNA glycosylase) 투여와 Comet asaay (single cell gel electrophoresis, 단세포겔전기영동기법)를 결합시켜 이용하는 Fpg/Endo III FLARE 분석법을 사용하였다. Fpg enzyme에 의한 olive tail moment값의 변화는 16주 노출군부터 노출부검(34주)군 까지 노출농도가 높아짐에 따른 olive tail moment 기하평균 값의 양 반응관계를 보기는 어렵지만, 고농도군의 경우 27주 노출군에서 가장 높은 olive tail moment 값을 보이고 이후 차츰 감소하였다. 한편 16주에서 22주까지의 노출기간에서는 대조군에 비해 노출군에서 DNA손상정도(olive tail moment값)는 모두 유의하게 높았으나, 6, 12, 18, 25, 31, 33, 35주간 노출하였을 때는 다른 결과를 보였다. 각 실험군의 Fpg enzyme에 의한 tail length값의 분포를 살펴볼 때, 저농도군 및 고농도군에서 27주간 노출하였을 때 가장 높은 tail length 값을 보이고 이후 차츰 감소하는 경향을 보였다. 또한 16, 22주간 노출하였을 때 대조군에 비해 노출군에서 tail length 값이 유의하게 높았으나, 20주간에서만 양 반응관계가 관찰되었고, 다른 주간에서는 양 반응 및 기간 반응관계를 나타내지는 않았다. Endo III enzyme에 의한 olive tail moment값의 변화는 기간별 노출군에서 대조군에 비해 높은 DNA손상정도(olive tail moment값)를 나타내는 결과들이 있었지만, 10, 12, 16, 22, 25, 31주간 노출하였을 때 등 상당수 노출기간에서 반응관계를 나타내지는 않았다. 각 실험군의 Endo III enzyme에 의한 tail length값의 분포를 살펴볼 때, 18, 20, 27, 33주간 노출하였을 때 대조군에 비해 노출군에서 tail length 값이 조금 높았지만, 양 반응 및 기간 반응관계를 보이지 않았고 수치의 크기가 불규칙하게 변화하였다. 즉, DNA에 있어 산화된 pyrimidine을 형성하여 손상된 부위의 염기를 제거함으로써 AP site (abasic site)를 만들고 이들이 Comet assay를 통해 break로 전환된 것을 포함한 DNA손상을 측정하기 위하여 endonuclease III (Endo III)를 첨가시킨 Endo III FLARE 분석법을 실시한 결과, 본 연구에서 나타난 결과는 용접흄 노출 영장류에서 Olive tail moment 및 tail length 공히 노출량 및 노출기간 반응관계를 볼 수 없었다. Endo III FLARE 분석법을 통한 산화적 DNA 손상지표는 영장류에 적용하기에는 적응반응현상으로 대조군과 유의한 차이도 관찰할 수 없었고 더욱이 역으로 대조군에서의 자연발생적 수치가 더 높아질 수 있어 용접흄 노출 영장류의 모니터링 지표로 사용하기에는 제한점이 있었다.

Spontaneous Pneumomediastinum: Clinical Investigation (자연성 종격동 기종의 임상적 고찰)

  • Park Jae Hong;Chei Chang Seck;Hwang Sang Won;Kim Han Yong;Yoo Byung Ha;Kim Dae Hwan
    • Journal of Chest Surgery
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    • v.39 no.3 s.260
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    • pp.220-225
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    • 2006
  • Background: Spontaneous pneumomediastinum is an uncommon, benign, self-limited disorders that usually occurs in young adults without any apparent precipitating factors or disease. The purpose of this study was to review our experience in dealing with this entity and describe a reasonable course of assessment and management. Material and Method: A retrospective case series was conducted to identify adults patients with SPM who were diagnosed and treated in a single institution between 2001 and 2005. Result: Fifteen patients were identified who included 14 men and 1 women with a mean age of 26 years. Presenting symptoms were chest pain in 12 patients ($80\%$), dyspnea in 5 patients ($33\%$), and throat discomfort in 4 patients ($26\%$). Two cases were associated with use of inhalational drugs and 3 cases were associated with exercise. The predisposing factors were asthma, excessive exercise, and vomiting in spontaneous pneumomediastinum. The physical findings were subcutaneous emphysema in 10 patients ($77\%$). Chest radiography and computerized tomography were the diagnostic methods in all cases with CT scan revealing six cases with associated pulmonary abnormalities. Esophagogram and flexible bronchoscopy were selectively used. Fifteen patients ($100\%$) were admitted to the hospital. Their mean hospital stay was 3 days. All patients were conservatively treated. In a follow-up of 3 years no complications or recurrences were observed. Conclusion: Most simple spontaneous pneumomediastinum cases were benign diseases and most of them ($77\%$) had shown typical chest pain, dyspnea and subcutaneous emphysema. Inhalational drug use was not a major cause of SPM; however, increased use of bronchoinhalers was a suspicious cause of SPM.

A Biomechanical Modeling of Human Pharyngeal Muscular Dysfunction by Using FEM(Finite Element Method) (유한요소법을 이용한 인두의 기능이상에 대한 생체역학적 모델)

  • Kim Sung Jae;Bae Ha Suk;Choi Byeong Cheol;Kim Sung Min
    • Journal of Biomedical Engineering Research
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    • v.24 no.6 s.81
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    • pp.515-522
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    • 2003
  • Pharynx is a system transporting foods by peristaltic motion(contraction and expansion movement! into the esophagus and functioning as airway passages. In this study, structural changes of pharyngeal dysfunction are analyzed by biomechanical model using CT and FEM(finite clement method). Loading condition was assumed that equal pressure was loaded sequentially to inside of pharyngeal tissue. In order to analyze the pharyngeal muscular dysfunction by biomechanical model. the pharyngeal dysfunctions was classified into 3 cases. Taking into account the clinical complication by neuromuscular symptoms such as pharyngeal dysfunction after stroke. we assumed that a change of material property is caused by muscular tissue stiffness. A deformation of cross sectional area of the pharynx is analyzed increasing the stiffness $25\%,\;50\%,\;75\%$ in each case on the basis of stress-strain relationship. Based on three-dimensional reconstruction of pharyngeal structure using limited factor - techniques and the optimization procedure by means of inverse dynamic approach. the biomechanical model of the human pharynx is implemented. The results may be used as clinical index illustrating the degree of pharyngeal muscular dysfunction. This study may be used as useful diagnostic model in discovering early deglutitory impediment caused by physiological or pathological pharyngeal dysfunction.

Analysis of Three Dimensional Liquid Ramjet Engine with Spray and Combustion (액체 램제트 엔진의 3차원 분무 및 연소 반응 해석)

  • 오대환;임상규;손창현;이충원
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.2
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    • pp.18-24
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    • 1999
  • Liquid ramjet combustor is closely connected with complex phenomena due to a series of processes such as intake air, spray, mixing, and combustion. The present numerical experiments were peformed to investigate these flow characteristics for two and three dimensional liquid ramjet combustor. Grid system was made with three domains: intake region where air is supplied and fuel is injected, combustor and nozzle region, and exit atmosphere region. The numerical results showed that two and three dimensional flow patterns in recirculation region of combustor were significantly different each other and spray model was necessary to predict correctly the chemical reaction flow characteristics. Numerically examined for two different location of fuel injector, one is located on the bottom position of curved intake and the other is located on the top position. We found that bottom position of fuel injector is better than top position because fuel influx to the recirculation region which is need to sustain chemical reaction is more than the latter.

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A Study on the Blade Load Measurement of Partial-admission Turbine Cascade (충동형 터빈 캐스케이드의 깃 하중 측정에 관한 연구)

  • Lim, Dong-Hwa;Jang, Jin-Man;Lee, Eun-Seok;Kim, Jin-Han;Choi, Jong-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.2
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    • pp.143-148
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    • 2007
  • An impulse turbine, which is a main component of a liquid rocket engine, needs to be a small size with light weight and generate large power. Since the impulse turbine is being operated under complicated supersonic conditions, flow analysis and performance prediction largely depend on CFD technique. In order to increase the reliability of the prediction code, however, it often requires an experimental data to compare. In this research a rotating turbine rotor with multiple blades is simulated with a two-dimensional stationary cascade to check the effect of major flow parameters. Mach number is measured at nozzle exit by using a pitot tube and the blade thrust was also measured with a load cell. The measured thrust coefficient and the power are compared well with the designed conditions, which proves the design procedures are properly taken.

A Controlled Trial of Placebo Versus Real Venesection (위자락과 진자락 요법에 관한 대조 시험)

  • Kim, Woo-Young;Baek, Seung-Tae;Byun, Hyuk;Lee, A-Ram;Jeong, Yong-Rae;Kim, Kap-Sung;Lee, Seung-Deok
    • Journal of Acupuncture Research
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    • v.22 no.6
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    • pp.125-134
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    • 2005
  • 목적 : 이 연구의 목적은 플라시보 자락요법을 계발하기 위함이다. 방법 : 이 연구에서 우리는 자락요법을 잘 알고 있는 특정 피시험군에 진자락요법과 위자락요법을 시행하고, 피시험자에게 본인이 받은 치료가 무엇이었는지 설문조사하였다. 위자락요법은 피부를 뚫어 혈관을 자파시키지 않고 피부 겉에서 느낌만 나도록 자극을 주고 흡입하는 것이다. 결과 : 총 53명의 피시험자가 모든 시험과정에 적절하게 참가하였으므로 모든 데이터를 신뢰할 수 있었다. 결과는 두 그룹간에 유의한 차이를 발견할 수 없었다. 위자락요법을 받은 피시험자중 44.4%는 그들이 받은 치료가 진자락요법이라고 생각했고, 55.6%는 위자락요법이라고 생각했다. 진자락요법을 받은 피시험자중 53.8%는 그들이 받은 치료가 진자락요법이라고 생각했고, 46.2%는 위자락요법이라고 생각했다. 결론 : 각 군간의 민감도와 특이도 간에 유의한 차이가 나타나지 않으므로, 자락요법에 있어 플라시보가 성공했다고 볼 수 있다. 이 연구는 자락요법을 적응증으로 하는 다양한 질환의 임상연구에 있어서 대조군 처치시 좋은 모델을 제시하였다.

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A Case of Giant Cell Interstitial Pneumonia without History of Exposure to Hard Metal (경금속에 대한 노출력이 없는 거대세포 간질성 폐렴(Giant Cell Interstitial Pneumonia) 1예)

  • Hong, Ji Hyun;Lee, Jae Myung;Kang, Min Jong;Kim, Dong Gyu;Jung, Ki-Suck;Jang, Kee-Tark;Park, Hye-Rim;Lee, In Jae
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.4
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    • pp.419-424
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    • 2002
  • A 44 year old man was admitted complaining fo exertional dyspnea. The patient denied any occupational history of hard metal exposure. Chest radiography showed an increased interstitial marking at the peripheral portion of both lower lung fields. The spirometric values were within the normal ranges. However, the diffusion capacity of the lungs was lower. In the bronchial lavage fluid, the characteristic multinucleated giant cells were noticed, and the macrophage compartment was 96% and the neutrophils were 4%. High-resolution CT scan revealed ground glass opacities with emphysematous lung changes at the peripheral portion of the whole lung. An open lung biopsy confirmed the presence of numerous multinucleated giant cells (define GIP) with an associated interstitial fibrosis throughout the lung. The radiographic abnormailities and symptoms subsequently improved following treatment with oral corticosteroids.

A Study on Improving Environmental Characteristics of Cyclone Vacuum Cleaner using Life Cycle Assessment (LCA 평가를 이용한 싸이클론 진공청소기의 친환경성 개선방안에 관한 연구)

  • Hwang, Bo-Seok;Yoon, Yong-Han;Lee, Chanhyun;Yi, Hwa-Cho
    • Clean Technology
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    • v.20 no.3
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    • pp.241-250
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    • 2014
  • In this study, performance and environmental characteristics of cyclone vacuum cleaners are analyzed and product improvement methods are investigated to minimize environmental effect of the cleaners using the result. A simplified LCA method is used to analyze environmental characteristics of the cyclone vacuum cleaners. Two cyclone vacuum cleaners with similar specifications are chosen for the experiment. Typical characteristics of cyclone vacuum cleaners such as energy consumption, suction force, noise and temperature are measured and compared. Most environmental effect was caused by the energy consumption in use phase of life cycle. Some ideas are created to reduce energy consumption of the vacuum cleaners in use phase like installing baffle, and methods to extend exchange period of filter. It is analyzed how recyclability rate of vacuum cleaners could be improved to reduce the environmental effect in whole life of the vacuum cleaners.

Manufacturing Method of Red Ginseng Extract Pills by Centrifugal Coating Granulating System (원심분리 코팅방식을 이용한 홍삼농축액 환의 제조방법)

  • Kwak, Yi-Seong;Choi, Young-Gi;Kwon, Hyun-Jeong;Kim, Na-Mi
    • Journal of Ginseng Research
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    • v.33 no.3
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    • pp.229-233
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    • 2009
  • The centrifugal coating granulating system, a new method of preparing red ginseng extract pills, has been developed. The red ginseng extract was first powdered with 85.5% of edible ethanol and dried for 3 to 4 hours at 50$^{\circ}C$. The powders were fed in chamber of centrifugal coating granulating system and then granulated, sequentially. The centrifugal system operated at 20 to 50$^{\circ}C$ of inlet temperature, 1 to 1,000 g/min of feeding speed, 60 to 70$^{\circ}C$ of atmosphere temperature of intake, 3.0 to 4.0 bar of spray atmosphere pressure, 1,000 to 1,500 rpm of centrifugal plate speed and 25 to 40$^{\circ}C$ of outlet temperature. The product yield was about 85% and preparation time was 7 to 8 hours. Especially, major ginsenoside components of red ginseng were not decomposed after processing of red ginseng extract pill.

The development of small water-jet propulsion for 150HP grade inboard type (150마력급 선내형 소형 워터제트 추진시스템 개발)

  • Lee, Joong-Seop;Lee, Chi-Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.246-252
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    • 2014
  • This study is on the development of 150PS inboard type of compact water jet propulsion system. The water jet is composed of intake, impeller, diffuser, reverse bucket and main shaft. Components of water jet have been manufactured through precision processing after sand casting. Development of water jet propelled engine has been finally completed by processes which are design, production and inspection on each component. The water jet performance characteristics show that 0.29 m3/s of maximum flow rate and 37 m/s of flow velocity have been secured in the ground test pool. Field test was performed by 21ft test ship that water jet propulsion equipment developed in this study was installed. As a result, the weight of hull, engine and other parts of the ship has been almost 1.2 ton and 45 km/h of maximum sailing speed has been recorded with 3700 rpm of engine in the domestic coast test.