• Mycobiology
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• v.44 no.1
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• pp.54-57
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• 2016

Davallialactone (DAVA) is a hispidin analogue derived from the medicinal fungus Phellinus baumii. We examined the effect of DAVA on in vitro fertilization (IVF) of pigs. Boar spermatozoa were incubated in fertilization medium with varying concentrations of DAVA, then sperm motility and reactive oxygen species (ROS) level were evaluated. Higher sperm motility was found following the addition of 0.5 or $1{\mu}M$ DAVA after incubation than addition of other concentrations or controls. ROS level decreased significantly with the addition of DAVA. The rate of normal fertilization was higher in the presence of $1{\mu}M$ DAVA (65.1%) than were those of other concentrations or controls (45.4~59.4%), and the highest total fertilization rate (mono- and polyspermic oocytes) was observed at $1{\mu}M$ DAVA (83%). In conclusion, addition of DAVA to fertilization medium improved sperm motility, and reduced ROS level so as to potentially improve sperm-oocyte binding in IVF, suggesting the potential of a compound isolated from mushrooms in assisted reproductive technology for humans and animals.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.625-627
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• 2016

본 논문은 EDISON CFD의 전처리기, eMEGA를 이용하여 격자를 생성하고, 2차원 정렬 격자 기반 비압축성 해석자를 이용하여 유동해석을 진행한 뒤 후처리기, eDAVA를 통해 유동선을 그려 블라인드 장착에 따른 실내 공기 순환에 대한 연구 내용을 담고 있다. 본 연구는 시중에 판매중인 사생활 보호용 블라인드를 포함, 여러 블라인드의 장착 여부에 따라 실내 내부 공기 순환의 양상을 확인하고 실제로 블라인드 장착 시 실내환기에 어떤 영향을 주는지 유동 선을 통해 확인해 보았다. 블라인드 미장착시, 실내 전체적으로 공기가 고루 순환되는 모습을 보였으며, 블라인드 장착 시 대체로 블라인드 형태에 따라 유동이 이동하는 것을 볼 수 있었다. 본 연구는 사생활 보호와 환기 효율성의 관점에서의 소비자 선택권에 영향을 미치는 효과를 가져 올 것으로 보인다.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.78-80
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• 2016

우주발사체와 항공 분야에서 초음속과 극초음속 영역에서 비행체의 항력을 최소화하기 위한 최적 형상설계 연구가 활발히 진행되고 있다. 본 논문에서는 마하수 2의 초음속 영역에서 대표적인 비행체 선두부 형상 3가지에 대한 수치해석을 eMEGA 프로그램을 활용해 격자를 생성하고 eDAVA 프로그램을 활용해 유동 해석을 수행하였다. 그 결과 자유유동 마하수 2의 초음속 영역에서는 선두부 형상이 뾰족한 Cone 형상이 3가지 형상 중 작용하는 항력이 가장 적게 나타났고, 선두부가 무딘 형상이 극초음속 영역에서 가장 적합한 현상과 다르게 나타났다.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.382-395
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• 1992

GABA is an inhibitory neurotransmitter in central nervous system and produce sedative, antianxiety and muscle reaxing effects via $GABA_A$ receptor or $GABA_B$ receptor. Recently it is known that GABA is widely distributed throughout peripheral organs and may playa physiological role in certain organ. The vas deferens is innervated by species-difference. These study, therefore, was performed to investigate the mode and the mechanism of action of GABA on the norepiniphrine-, ATP- and electric stimulation-induced contraction of vas deferens of rat. Sprague-Dawley rats were sacrificed by cervical dislocation. The smooth muscle strips were isolated from the prostastic portion and were mounted in the isolated muscle bath. PSS in the bath was aerated with 95/5%-$O_2/CO_2$ at $33^{\circ}C$. Muscle tensions were measured by isometric tension transducer and were recorded by biological recording system. 1. GABA, muscimol, a $GAB_A$ agonist, and baclofen, a $GABA_B$ agonist inhibited the electric field stimulation(EFS, 0.2Hz, 1mSec, 80 V, monophasic square wave)-induced contraction with a rank order of potency of GABA greater than baclofen greater than muscimol. 2. The inhibitory effect of GABA was antagonized by delta aminovaleric acid(DAVA), a $GABA_B$ antagonist, but not by bicuculline, a $GABA_A$ mtagonist. 3. The inhibitory effect of baclofen was antagonized by DAVA, but the effect of muscimol was not antagonized by bicuculline. 4. Exogenous norepinephrine(NE) and ATP contracted muscle strip concentration dependently, but the effect of acetylcholine was negligible : and GABA did not affect the NE-and ATP-induced contractions. 5. GABA, baclofen and muscimol did not affect basal tone, and GABA did not affect the NE-and ATP-induced contractionsm 6. EFS-induced contraction was including 2 distinctable components. The first phasic component was inhibited by beta gamma-methylene ATP(mATP), a desensitizing agent of APT receptor and the second tonic component was reduced by pretreatment of reserpine(3 mg/Kg, IP). 7. GABA inhibited the EFS-induced contraction of reserpinized strips, but not the mATP-treated strips. These results suggest that in the prostatic portion of the rat vas deferens, adrenergic and purinergic neurotransmissions are exist, and GABA inhibits the release of ATP via presynaptic $GABA_B$ receptor on the excitatory neurons.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.49-54
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• 2016

본 연구에서는 유/무인 우주발사체의 재진입모듈에 적용되는 Heat-Shield(열차단막)의 형상에 따른 유동특성을 수치해석으로 분석했다. 재진입모듈이 지구의 대기권을 다시 진입하는 환경(고도 70km)을 기준으로 해석을 진행했다. 열차단막의 형상은 평판, 곡률이 다른 타원으로 나누었으며, 각 형상별 유동특성을 확인했다. 결론적으로 재진입 모듈의 형상에 따라 압력과 속도분포를 기준으로 열적인 분포를 예상했으며, 계산된 항력계수를 비교했다. 단순한 유동으로 열적 분포를 예상한 것에 한계가 있지만 대기권 재진입 모듈의 2차원 설계에 도움이 될 형상기준을 제시했다. 수치해석은 모두 Edison_CFD에서 제공하는 툴을 이용해 수행했으며, 전처리에는 e-mega (structured)을 후처리에는 e-dava를 이용했다. 해석 solver는 '정렬격자기반 2차원 압축성 유동 범용해석 소프트웨어'를 이용했다.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.314-322
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• 1994

This study aimed to investigate the existence of GABA receptor and the mechanisms of action of GABA and diazepam on the trachealis muscle isolated from dog. Horizontal muscle strips of $2mm{\times}15mm$ were prepared from canine trachea, and isometric myography in isolated muscle chamber bubbled with 95/5%-$O_2/CO_2$at $36^{\circ}C$, at the pH of 7.4 was performed. Muscle strips contracted responding to the electrical field stimulation (ESP) by 2~20 Hz, 20 msec, monophasic square wave of 60 VDC GABA and diazepam suppressed the EFS-induced contractions to the similar extent, significantly. (p<0.05) Bicuculline, a $GABA_A$ receptor antagonist blocked both GABA- and diazepam- inhibitions; but DAVA, a $GABA_B$ receptor antagonist did not affect either of them. These results suggest that in the canine trachealis muscle, there may be only $GABA_A$ receptor, and GABA and diazepam inhibit the contractility via $GABA_A$A receptor.