• Title/Summary/Keyword: Oxygen deficiency

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Saccharomyces cerevisiae에서 myo-Inositol 결핍에 의한 Respiratory capacity의 감소

  • 정경환;이준식
    • Microbiology and Biotechnology Letters
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    • v.24 no.4
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    • pp.485-492
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    • 1996
  • myo-Inositol, a growth factor for Saccharomyces cerevisiae (S. cerevisiae), has been known to be incorporated into phosphatidylinositol (PI), which is a kind of phospholipid in the cell membrane, by a membrane-associated PI-synthesizing enzyme. The deficiency of myo-inositol in S. cerevisiae adversely affected the membrane structure and function. On the basis of biochemical functions of myo-inositol, the effect of deficiency of myo-inositol on the aerobic glucose metabolism was investigated by measuring specific oxygen uptake rate (Q$_{O2}$) used as an indicator representing the respiratory capacity of S. cerevisiae in batch and continuous cultures. The respiratory capacity of aerobic glucose metabolism in S. cerevisiae was also monitored after glucose pulse-addition in a continuous culture (D=0.2, 1/hr), in which glucose was utilized through respiratory metabolism. The deficiency of myo-inositol was found to lead to both the decrease of the maximum specific oxygen uptake rate (Q$_{O2max}$) observed from the batch as well as in the continuous culture experiment and the decrease of the respiratory capacity of aerobic glucose metabolism of S. cerevisiae determined from the glucose pulse-addition experiment, in which the glucose flux into respiratory and fermen- tative metabolism was quantitatively analyzed.

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A Study on Statistics for Accidents in Confined Space in Korea (밀폐공간 질식재해 통계현황 분석)

  • Yoo, Kye-mook;Park, Hyun-hee;Chung, Kwang-Jae
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.4
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    • pp.363-369
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    • 2009
  • The total number of confined space accident cases from 1999 to 2007 in Korea were 220, causing 353 injuries and 212 casualties. Out of 220 cases, 44(20.0%) occurred in sewage treatment facilities and 40(18.2%) occurred in both manholes and containers. When the main causes of confined space accidents were classified, oxygen deficiency accounted for 69 cases(31.4%), carbon monoxide, 48(21.8%), hydrogen sulfide, 40(18.2%), and organic solvent, 32(14.5%). Improvement of occupational accident statistics is necessary in order to report accurate and precise data for confined space accidents. The structure of confined space must be considered when selecting gas to be measured.

Numerical Study on the HCFC-123 Leak in Turbo Chiller by using CFD (터보냉동기의 HCFC-123 누출에 대한 수치해석 연구)

  • Seo, Hoekyeong;Song, Sewook;Hwang, Yangin;Ha, Hyunchul
    • Journal of the Korean Institute of Gas
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    • v.18 no.5
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    • pp.85-90
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    • 2014
  • Turbo chiller is widely used for the air conditioner and uses hydrochlorofluorocarbon 123 (HCFC-123) as a refrigerant. HCFC-123 is one of the chemicals being considered as a replacement for the chlorofluorocarbons. High concentrations of HCFC-123 cause a deficiency of oxygen with the risk of unconsciousness or death, the vapour is heavier than air and may accumulate in low ceiling spaces causing deficiency of oxygen. In this study, the concentration distribution of oxygen indoor was investigated by using computational fluid dynamics(CFD) as four workers were killed in HCFC-123 gas leaks at machine room of hypermarket in 2011.

Effect of oxygen defects on luminescent characteristics of ZnGa_2O_4$:Mn phosphors (산소 결함이 ZnGa_2O_4$:Mn형광체 발광 특성에 미치는 효과)

  • 박용규;한정인;곽민기;한종근;주성후
    • Electrical & Electronic Materials
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    • v.9 no.10
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    • pp.1040-1046
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    • 1996
  • Low voltage phosphor, ZnGa$_{2}$O$_{4}$:Mn, was synthesized and sintered at the high temperature in Ar or vacuum. By XRD analysis, it is confirmed that poly crystalline ZnGa$_{2}$O$_{4}$:Mn solid solution was formed. From EPMA analysis of the samples prepared in Ar and vacuum, the change of oxygen content was investigated and as a result, it was observed that the oxygen amounts were reduced in ZnGa$_{2}$O$_{4}$:Mn prepared in vacuum. It caused the deficiency in oxygen amounts in the phosphor and then consequently, it results in the formation of the energy level near 513 nm. It contributes to the improvement of the brightness of ZnGa$_{2}$O$_{4}$:Mn.

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The Solar Nebular on Fire: A Solution to the Carbon Deficit in the Inner Solar System

  • Lee, Jeong-Eun;Bergin, Edwin A.;Nomura, Hideko
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.91.1-91.1
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    • 2010
  • Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon grains in the Solar Nebula. We present a solution wherein primordial carbon grains are preferentially destroyed by oxygen atoms ignited by heating due to stellar accretion at radii < 5 AU. This solution can account for the bulk carbon deficiency in the Earth and meteorites, the compositional gradient within the asteroid belt, and for growing evidence for similar carbon deficiency in rocks surrounding other stars.

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Research Trends of Interstitial Lung Disease (간질성 폐질환의 연구 동향)

  • Son, Ji-Woo;Lee, Jung-Wook;Lee, Byung-Soon;No, Woon-Serb;Lee, Byung-Ju;Shin, Jo-Young;Lee, Si-Hyeong
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.13 no.1
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    • pp.26-38
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    • 2007
  • Interstitial lung disease (ILD) is characterized by progressive scarring of the lung leading to restriction and diminished oxygen transfer. Clinically, the presenting symptoms of ILD are nonspecific (cough and progressive dyspnea on exertion) and are often attributed to other diseases, thus delaying diagnosis and timely therapy. In this study, I analyzed the 10 chinese papers of interstitial lung diseases(ILD). The etiology are body resistance weakness(本虛) and pathogenic factor prevailing(標實). The body resistance weakness(本虛) including deficiency of the lung(肺虛), deficiency of the kidney(腎虛), deficiency of the spleen(脾虛), deficiency of Qi and Yin(氣陰兩虛), pathogenic factor prevailing(標實) including stagnation of phlegm(痰濁), blood stasis(瘀血), noxious heat(熱毒). As an treatment aim at supplementing lung and kidney(益肺腎), resolving phlegm and blood stasis(化痰瘀).

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Experimental Chemical Treatments for the Control of Dinoflagellate Cochlodinium polykrikoides in the Land-based Culture of Olive Flounder Paralichthys olivaceus (넙치 육상수조 양식에 있어 편조류 Cochlodinium polykrikoides의 구제를 위한 화학적 처리)

  • Ryu, Ho-Young;Shim, Jeong-Min;Bang, Jong-Deuk;Lee, Chu
    • Journal of Aquaculture
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    • v.11 no.3
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    • pp.285-294
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    • 1998
  • When Cochlodinium polykrikoides came into the culture tanks through influent cultivated water during the red tides, hundred thousands of commercial flounders were concomitantly killed and many culturists suffered from a great deal of financial loss in the east coast of Korea. It is charactrized by high sinking rate after sunset and the formatino of clump which results in oxygen deficiency by its respiration at tank bottom under condition. We investigated the efficacy of hydrogen peroxide and chlorine dioxide, known to form radicals, for extermination of red tide organism C. polykrikoides. When C. polykrikoides seawater with a density of 6,000 cells/$m\ell$ was treated with 14, 28 and $42mg/\ell$ of hydrogen peroxide, its survival rate was markedly decreased to 9.8, 0.8 and 0.3% respectively immediately after 6 hours of treatments whereas when it was treated with 1.5, 2.1 and $3.0mg/\ell$ chlorine dioxide, its survival rate showed 87.7, 81.3 and 80.1 and 80.1% respectively at the same treatment time. Hydrogen peroxide was the effective agent since it has scarcely injured the cultured olive flounder when exposed to the tested concentration range of $14~28mg/\ell$ with the extermination of almost3 C. polykrikoides during the experimental period of 5 days and has shown the oxygen increase of approximately $1.23mg/\ell$ 2 hours immediately after the flounder by C. polykrikoides in the land-based culture tank is assumed to be not by the toxicity of itself but by oxygen dificiency from the rapid respiration of dinoflagellate clump sunken to the tank bottom.

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Electrical Characteristics of ZnO Piezo-electric Thin film for SAW filter (SAW 필터용 ZnO 압전 박막의 전기적 특성)

  • Lee, Dong-Yoon;Yoon, Seok-Jin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.10
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    • pp.909-916
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    • 2005
  • The structural and electrical property of RF magnetron sputtered ZnO thin film have been studied as a function of RF power, substrate temperature, oxygen/argon gas ratio and film thickness at constant sputtering power, sputtering working pressure and target-substrate distance. To analyze a crystallo-graphic properties of the films, $\theta$/2$\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity and surface roughness highly depended on oxygen/argon gas ratio. The resistivity of ZnO thin film(6000 ${\AA}$) rapidly increased with increasing oxygen ratio and the resistivity value of $9 {\ast} 10^7 {\Omega}cm$ was obtained at a working pressure of 10 mTorr with the same oxygen/argon gas ratio. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with the same oxygen/argon gas ratio showed the excellent roughness value of 28.7 ${\AA}$. With increase of the substrate temperature, The C-axis preferred orientation of ZnO thin film increases and the resistivity decreases due to deviation from the stoichiometric ZnO due to oxygen deficiency.