• 제목/요약/키워드: Reduced mechanism

검색결과 2,190건 처리시간 0.028초

황기(黃芪)가 Intracerebral Hemorrhage 흰쥐의 뇌부종(腦浮腫)에 미치는 영향 (Effects of Astragali Radix on Brain Edema and Apoptosis in Intracerebral Hemorrhage of Rats)

  • 정형진;박완수;김연섭
    • 동의생리병리학회지
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    • 제24권6호
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    • pp.1027-1033
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    • 2010
  • This study aimed to evaluate the effects of Astragali radix on brain edema of intracerebral hemorrhage(ICH)-induced rats. Brain edema following ICH was induced via the stereotaxic intrastriatal injection of bacterial collagenase type VII in Sprague-Dawley rats. Ethanol extract of Astragli radix was treated once a day for 3 days. Then brain hematoma volume and edema were examined. Immunohistochemistry was processed for iNOS, c-Fos, Bax, and HSP72 expressions in the brain sections and each immuno-labeling were calculated with image analysis. Ethanol extract of Astragli radix reduced hematoma volume(not significantly) and brain edema(significantly) ICH induced rats. Ethanol extract of Astragli radix reduced iNOS expressions, c-Fos, Bax and HSP72 positive cells significantly and reduced apoptotic bodies and swollen neurons in ICH induced rat brain. These results suggest that Astragli radix plays an inhibitory role in the hemorrhagic, inflammatory and apoptotic events induced by ICH. And it is supposed that neuroprotective effect of Astragli radix reveals by anti-apoptosis mechanism.

Breeding of New Strains of Mushroom by Basidiospore Chemical Mutagenesis

  • Lee, Ji-A;Kang, Hyeon-Woo;Kim, Sang-Woo;Lee, Chang-Yun;Ro, Hyeon-Su
    • Mycobiology
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    • 제39권4호
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    • pp.272-277
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    • 2011
  • Chemical mutagenesis of basidiospores of Hypsizygus marmoreus generated new mushroom strains. The basidospores were treated with methanesulfonate methylester, an alkylating agent, to yield 400 mutant monokaryotic mycelia. Twenty fast-growing mycelia were selected and mated each other by hyphal fusion. Fifty out of the 190 matings were successful (mating rate of 26.3%), judged by the formation of clamp connections. The mutant dikaryons were cultivated to investigate their morphological and cultivation characteristics. Mutant strains No. 3 and No. 5 showed 10% and 6% increase in fruiting body production, respectively. Eight mutant strains showed delayed and reduced primordia formation, resulting in the reduced production yield with prolonged cultivation period. The number of the fruiting bodies of mutant No. 31, which displayed reduced primordial formation, was only 15, compared to the parental number of 65. Another interesting phenotype was a fruiting body with a flattened stipe and pileus. Dikaryons generated by mating with the mutant spore No. 14 produced flat fruiting bodies. Further molecular biological studies will provide details of the mechanism. This work shows that the chemical mutagenesis approach is highly utilizable in the development of mushroom strains as well as in the generation of resources for molecular genetic studies.

김치숙성 중 유리당의 변화 (Changes of Free Sugars in Kimchi during Fermentation)

  • 하재호;허우덕;김영진;남영중
    • 한국식품과학회지
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    • 제21권5호
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    • pp.633-638
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    • 1989
  • 김치숙성 중 유리당의 변화를 GC로서 분석하였다. 김치에 존재하는 주요 유리당은 mannose, fructose, glucose, galactose등이었고 이들은 숙성이 진행됨에 따라 점차 감소한 반면 mannitol은 숙성이 진행됨에 따라 생성되었다가 서서히 감소하였다. 여러종류의 김치 중 유리당의 변화를 비교한 결과 그 변화양상이 비슷하였으며, 이로부터 대부분의 김치는 비슷한 발효기작을 따르는 것 같았다.

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Ameliorative Potential of Rengyolone Against CCI-induced Neuropathic Pain in Rats

  • Lee, Gil-Hyun;Hyun, Kyung-Yae
    • 대한의생명과학회지
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    • 제26권4호
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    • pp.310-318
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    • 2020
  • The sciatic nerve is the largest nerve among the peripheral nerves, and the damage to the sciatic nerve is caused by mechanical and physical pressure. This is an important disease that consumes a lot of time and money in the treatment process. Among them, research on relieving nerve pain caused by damage to the peripheral sciatic nerve has been made efforts to prevent and treat this disease through various methods such as drugs, natural products, electrical stimulation, exercise therapy, and massage. Existing treatments are not very effective in neurological pain, and countermeasures are needed. Forsythia Fructus, used in this study, has been used as a therapeutic agent for infectious diseases and a pain reliever for cancer from the past, and in past studies, it has been known to properly control the inflammatory response. In this study, rengyolone, a physiologically active substance of Forsythiae Fructus, was administered to rats that caused chronic left nerve pain to verify the pain relief effect. As a result of the experiment, it was found that mechanical pain and cold stimulation pain were significantly reduced in the rengyolone-treated group compared to the non-administered group. In addition, it was found that nerve growth factor (NGF) mRNA expression was significantly reduced and Cyclin-dependent kinase 2 (Cdc2) expression was increased in the rengyolone administration group. This increase in NGF expression is thought to be related to rengyolone's anti-inflammatory regulatory mechanism. It is expected that the reduced NGF was directly involved in pain relief.

Application of Digital Image Correlations (DIC) Technique on Geotechnical Reduced-Scale Model Tests

  • Tong, Bao;Yoo, Chungsik
    • 한국지반신소재학회논문집
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    • 제21권1호
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    • pp.33-48
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    • 2022
  • This paper presents illustrative examples of the application of advanced digital image correlation (DIC) technology in the geotechnical laboratory tests, such as shallow footing test, trapdoor test, retaining wall test, and wide width tensile test on geogrid. The theoretical background of the DIC technique is first introduced together with fundamental equations. Relevant reduced-scale model tests were then performed using standard sand while applying the DIC technique to capture the movement of target materials during tests. A number of different approaches were tried to obtain optimized images that allow efficient tracking of material speckles based on the DIC technique. In order to increase the trackability of soil particles, a mix of dyed and regular sand was used during the model tests while specially devised painted speckles were applied to the geogrid. A series of images taken during tests were automatically processed and analyzed using software named VIC-2D that automatically generates displacements and strains. The soil deformation field and associated failure patterns obtained from the DIC technique for each test were found to compare fairly well with the theoretical ones. Also shown is that the DIC technique can also general strains appropriate to the wide width tensile test on geogrid, It is demonstrated in this study that the advanced DIC technique can be effectively used in monitoring the deformation and strain field during a reduced-scale geotechnical model laboratory test.

Development of reduced-order thermal stratification model for upper plenum of a lead-bismuth fast reactor based on CFD

  • Tao Yang;Pengcheng Zhao;Yanan Zhao;Tao Yu
    • Nuclear Engineering and Technology
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    • 제55권8호
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    • pp.2835-2843
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    • 2023
  • After an emergency shutdown of a lead-bismuth fast reactor, thermal stratification occurs in the upper Plenum, which negatively impacts the integrity of the reactor structure and the residual heat removal capacity of natural circulation flow. The research on thermal stratification of reactors has mainly been conducted using an experimental method, a system program, and computational fluid dynamics (CFD). However, the equipment required for the experimental method is expensive, accuracy of the system program is unpredictable, and resources and time required for the CFD approach are extensive. To overcome the defects of thermal stratification analysis, a high-precision full-order thermal stratification model based on CFD technology is prepared in this study. Furthermore, a reduced-order model has been developed by combining proper orthogonal decomposition (POD) with Galerkin projection. A comparative analysis of thermal stratification with the proposed full-order model reveals that the reduced-order thermal stratification model can well simulate the temperature distribution in the upper plenum and rapidly elucidate the thermal stratification interface characteristics during the lead-bismuth fast reactor accident. Overall, this study provides an analytical tool for determining the thermal stratification mechanism and reducing thermal stratification.

유기인제의 수소 환원 (Reduction Mechansim of Organophosphorus Compounds)

  • 이명연
    • 대한화학회지
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    • 제13권2호
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    • pp.141-147
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    • 1969
  • Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

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바이오디젤 엔진의 연소과정 모델링 (Modeling of Biodiesel Combustion on Compression Ignition Engine)

  • 최민기;차준표;박성욱
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.309-310
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    • 2012
  • Modeling of biodiesel combustion on compression ignition engine was conducted by using the KIVA3v-Release 2 code coupled with Chemkin chemistry solver2. In order to calculate the chemical kinetics of combustion of biodiesel, a reduced mechanism of methyl decanoate and methyl 9-decanoate was used. It is composed of 123 species and 394 reactions. Also, the experiments were performed on a single-cylinder engine. The simulation results agreed well with experiments results. And soot concentrations of biodiesel were lower than those of diesel.

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반도체 가스감지소자를 위한 공간전하 모델 (A Space Charge Model for Semiconductor Gas Sensors)

  • 이성필;이덕동;손병기
    • 대한전자공학회논문지
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    • 제26권11호
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    • pp.1631-1636
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    • 1989
  • A space charge model for semiconductor reduced gas sensors has been roposed and applied to gas sensing mechanism. SnO2-x and SnO2-x/Pt thin film were deposited by vacuum evaporating method. And Hall effect and gas sensitivity characteristics of these sensors were measured. From the space charge model and carrier concentration, the number of the adsorbed gas atom on the solid surface was calculated quantitatively. The gas sensing model was compared with CO gas sensitivities of the fabricated thin film gas sensors.

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Towards an Improved Understanding of Bond Behaviors

  • Choi, Oan Chul
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.239-243
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    • 2003
  • A reducing bearing angle theory for bond of ribbed reinforcing bars to concrete is proposed to simulate experimental observation. Analytical expressions to determine bond strength for splitting and pullout failure are derived, where the bearing angle is a key variable. As bearing angle is reduced, splitting strength decreases and shearing strength increases. The proposed reducing bearing angle theory is effective to simulate damage of the deformed bar-concrete interface and understand bond mechanism of ribbed reinforcing steel in concrete structures.

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