• 한국작물학회지
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• 제61권4호
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• pp.270-276
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• 2016

The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity ($F_m$) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield ($F_v/F_m$) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity ($F_m$) and Maximum fluorescence value ($F_p$) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (${\Phi}PSII$). Thus, NPQ and ${\Phi}PSII$ were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.

• Journal of Animal Science and Technology
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• 제47권2호
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• pp.195-204
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• 2005

The current study was conducted to investigate the effects of dietary conjugated linoleic acid(CLA) on growth performance and body fat metabolism in broiler chickens. A total of 48 male birds aged 3 days were randomly allotted into three dietary groups; CORN(com oil 1.5%), CLA I (com oil 0.75 %+ CLA 0.75 %) and CLA II(CLA 1.5%) groups. After feeding commercial diet ad libitum for 3 weeks, eight selected birds on the basis of body weight were housed, two birds in a cage, and continuously given ad libitum corresponding experimental diet for another 2 weeks. As a result, dietary addition of CLA did not influence on body weight, gain and feed conversion rote. The relative weights of the liver and deposited fats(abdominal and thigh fat' pads) were not also affected by the dietary treatments. Serum glucose, triglyceride and cholesterol levels markedly( P < 0.05) decreased in CLA II compared with those in CORN group. However, serum nonesterified fatty acid(NEFA) was not altered by dietary CLA. Serum leptin level was tended to be decreased by dietary CLA without statistical difference. The diet supplemented with CLA caused a significant(P< 0.05) decrease in hepatic total lipid and NEFA without changing triglyceride level. Also, feeding dietary CLA at the level of 1.5% reduced leptin mRNA expression in the liver and abdominal fats compared with feeding com oil, In conclusion, our results suggest that dietary 1.5% CLA may affect, at least in part, lipid metabolism in the liver of broiler chickens.

• 한국산업보건학회지
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• 제26권2호
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• pp.109-118
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• 2016

Objectives: To review reference levels by the international and domestic management and provide the basis for setting occupational exposure limits(OELs) of radon in Korea Methods: Government's organizations with laws and systems for monitoring radon exposure were investigated and compared. There are five laws governing Indoor Air Quality(IAQ) control such as Occupational Safety and Health Act, Indoor Air Quality Control in Public Use Facilities, Etc. Act, School Health Act, Public Health Control Act and Parking Lot Act in Korea. It was surveyed that a total of 32 countries including 24 countries in the European Union(EU), six countries in Asian and two countries in North America setting the reference levels for radon in the world. Results: In Korea, there are set guidelines for radon in the Ministry of Environment and the Ministry of Education. Reference levels of radon for existing dwellings were $150{\sim}400Bq/m^3$ for Western European countries, and $200{\sim}1,500Bq/m^3$ in Eastern European countries. Approximately 67% of those EU countries were set up $400Bq/m^3$ to the standards for existing dwellings. EU countries such as Luxembourg, Finland, Norway, Sweden and Russia had adopted mandatory level for radon. Radon guidelines for new dwellings were set more strictly reference level($200Bq/m^3$) than existing dwellings. Conclusions: International organizations such as ICRP, UNSCEAR and NCRP, etc. had recommended the guidelines for radon. It was calculated the relation of the dose conversion factors with the annual effective doses. the OELs of radon suggest to need to establish $150Bq/m^3$ for office room and $400{\sim}1,000Bq/m^3$ for the workplace.

• 한국식품과학회지
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• 제2권2호
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• pp.56-59
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• 1970

단세포단백질의 국내생산을 목적으로 전국 각지의 토양을 비롯한 기타 시료 357 종에서 900 여주의 탄화수소 자화균주를 분리하였고, 그중에서 비교적 수율이 좋은 효모 7주에 대한 균학적 성질을 조사한 결과 Candida tropicalis(5주), Candida lypolitica (1주), Torulopsis sp (1주)로 동정되었다. 선정된 효모균주의 mass doubling time은 $2.9{\sim}4.5$ hr., 수율은 $6.5{\sim}16.3g/l$, 경유 및 등유의 균체로의 전환율은 $7.8{\sim}19.3%$이고 ,건조효모의 조단백질함량은 $48.8{\sim}59.8%$이었다.

• Journal of Ginseng Research
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• 제13권1호
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• pp.98-104
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• 1989

In order to determine the specific active oxygen species directly related to chlorophyll bleaching in the leaf-burning disease, we investigated the effects of singlet oxygen (1O2), superoxide radical (O2-), and hydrogen Peroxide (H2O2) on isolated chloroplast suspension and leaf discs from Panax ginseng C.A. Meyer. When the singlet oxygen was added to the chloroplast suspension, the chlorophyll and carotenoid contents were decreased by more than 809), similar to treatment with high light intensity (100 KLux). We assumed that the conversion of dioxygen (O2) produced either in photolysis or in breakdown of hydrogen peroxide to singlet oxygen resulted from photorespiration. On the basis of these experiments , :he inhibitory effects of active oxygen scavengers propylgallic acid (PGA), 2,5-ditetrabutyl hydroquinon (DBH), sodium pyrosulfate (SPS), and ascorbic acid (ABS) were examined. In chloroplast suspension all four scavengers inhibited chlorophyll bleaching by more than 75fl , and in the leaf discs the inhibition rates of SPS, PGA and ABS were 46%, 51%, and 96% respectively.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1750-1759
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• 2020

The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated K_D value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min^-1 nmol^-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

• Archives of Pharmacal Research
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• 제29권10호
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• pp.874-878
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• 2006

Methyl gallate (MG) is a medicinal herbal product that is isolated from Paeonia lactiflora that inhibits cyclooxygenase-2 (COX-2) dependent phases of prostaglandin $D_2\;(PGD_2)$ generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with an $IC_{50}$ values of $17.0\;{\mu}M$. This compound also found inhibited the COX-2-dependent conversion of the exogenous arachidonic acid to $PGD_2$ in a dose-dependent manner with an $IC_{50}$ values of $190\;{\mu}M$, using a COX enzyme assay kit. However, at concentrations up to $80\;{\mu}M$, MG did not inhibit COX-2 protein expression in BMMC, indicating that MG inhibits COX-2 activity directly. Furthermore, MG consistently inhibited the production of leukotriene $C_4\;(LTC_4)$ in a dose dependent manner, with an $IC_{50}$ value of $5.3\;{\mu}M$. These results demonstrate that MG has a dual cyclooxygenase-2/5-lipoxygenase inhibitory activity, which might provide the basis for novel anti-inflammatory drugs.

• 한국전산구조공학회논문집
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• 제21권3호
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• pp.233-238
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• 2008

본 논문에서는 등기하 해석법을 이용하여 선형 탄성문제에 대한 형상 최적설계 기법을 개발하였다. 실용적인 공학문제에 대한 많은 최적설계 문제에서는 초기의 데이터가 CAD 모델로부터 주어지는 경우가 많다. 그러나 대부분의 설계 최적화 도구들은 유한요소법에 기초하고 있기 때문에 설계자는 이에 앞서 CAD 데이터를 유한요소 데이터로 변환해야 한다. 이 변환과정에서 기하 모델의 근사화에 따른 수치적 오류가 발생하게 되고, 이는 응답 해석뿐만 아니라 설계민감도 해석에 있어서도 정확도 문제를 발생시킨다. 이러한 점에서 등기하 해석법은 형상 최적설계에 있어서 유망한 방법론 중 하나가 될 수 있다. 등기하 해석법의 핵심은 해석에 사용되는 기저 함수와 기하 모델을 구성하는 함수가 정확히 일치한다는 것이다. 이러한 기하학적으로 정확한 모델은 설계민감도 해석 및 형상 최적설계에 있어서도 사용된다. 이로 인해 높은 정확도의 설계민감도를 얻을 수 있으며, 이는 설계구배 기반의 최적화에 있어서 매우 중요하게 작용한다. 수치 예제를 통하여 본 논문에서 제시된 등기하 해석 기반의 형상 최적설계 방법론이 타당함을 확인하였다.

• Geomechanics and Engineering
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• 제8권2호
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• pp.283-303
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• 2015

To research and analyze the differential settlements of foundations specifically, site investigations of existing railways and metro were firstly carried out. Then, the centrifugal test was used to observe differential settlements in different position between foundations on the basis of investigation. The theoretical model was established according to the stress diffusion method and Fourier method to establish an analytical solution of embankment differential settlement between different foundations. Finally, theoretical values and experimental values were analyzed comparatively. The research results show that both in horizontal and vertical directions, evident differential settlement exists in a limited area on both sides of the vertical interface between different foundations. The foundation with larger elastic modulus can transfer more additional stress and cause relatively less settlement. Differential settlement value decreases as the distance to vertical interface decreases. In the vertical direction of foundation, mass differential settlement also exists on both sides of the vertical interface and foundation with larger elastic modulus can transfer more additional stress. With the increase of relative modulus of different foundations, foundation with lower elastic modulus has larger settlement. Meanwhile, differential settlement is more obvious. The main error sources in theoretical and experimental values include: (a) different load form; (b) foundation characteristics differences; (c) modulus conversion; (d) effect of soil internal friction.

• 디지털콘텐츠학회 논문지
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• 제15권1호
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• pp.113-120
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• 2014

최근 들어 스마트폰과 IT기기를 이용한 서비스가 활성화되고, 어떻게 하면 두 가지 이상의 기기를 이용해 융합을 할 수 있을 것인가에 대한 관심이 대두되고 있다. 그중 하나로 모바일 분야에서 네트워크와 하드웨어의 발전을 통해 디지털 지리공간 및 컴퓨터 지도의 급속한 발전이 이뤄지고, 어떻게 하면 효율적으로 지도 데이터를 3D 환경에서 시뮬레이션하고, 가상환경을 통해 서비스를 제공할 것인가에 초점이 맞춰져있다. 본 연구에서는 증강현실과 GIS(Geographic Information System), SLM(Static LOD Model)을 융합한 기술로 증강현실의 기본적 개념과 접근법을 기본으로 지리적인 공간에서 어떻게 증강현실을 재해석하고 이를 기반으로 관련 컨텐츠의 개발과 활용을 어떻게 하는가에 목적을 가지고 있다. 본 연구에서는 기존의 3DS 모델의 데이터 구조를 제안한 SLM 데이터 포맷으로의 전환하기 위한 가능성을 분석하고, SLM 모델 포맷의 생성 및 가시화 도구는 기존 3차원 모델 포맷을 SLM 모델로 포맷을 변환하기 위한 기능 및 가시화 기능을 제공한다. 또한, 3D 가상 모델을 효율적으로 만들기 위한 포맷을 제안한다.