• 공학교육연구
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• 제19권5호
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• pp.65-71
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• 2016

The purpose of this paper is to research the effect of a reflection journal on self motivated-learners' study. The learners were divided into experimental and control groups, we carried out the pre- and post- surveys, and compared the groups' academic achievements. As a result, their persistent learning, self-efficacy, learning attitude somewhat improved and their academic achievement as well.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.532-535
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• 1987

A laser interferometry of very high spatial resolution was built to study the solid phase epitaxial regrowth of furnace-annealed silicon wafers. As boron concentration increases up to $1.0E20/cm^3$, regrowth rate increases, but pre-exponential term and activation energy are decreased.

• 대한의용생체공학회:의공학회지
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• 제24권4호
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• pp.241-246
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• 2003

정상 성인을 대상으로 언어생성과제의 시각적 지시과제와 청각적 지시과제에 대한 기능적 MR영상들을 비교하고자 하였다. 6명의 정상 성인을 대상으로 자기공명영상기기를 이용하였다 시각적, 청각적 언어 지시과제는 명사의 언어를 이용하여. 휴지기. 확성기를 각각 6번 구성하였다. 뇌의 활성영역의 휴지기와 확성기의 신호변화에 따른 데이터는 MRDx 프로그램으로 처리하였고 cross correlation 방법으로 통계 처리하였다. 시각적, 청각적 지시과제의 분석방법은 lateralization index 공식으로 뇌 반구의 활성화 voxel의 총합과 좌$.$우 반구의 픽셀 수를 구하였고, 지시 과제에 대한 활성화 영역을 “Area of Activation Cells” 값에 따라 4등급으로 분류하여 비교 분석하였다. 시간적 청각적 지시과제에서 Broca, Wernicke 영역 등에서 크기는 다르지만 모두 활성화가 관찰되었다. lateralization index에서 뇌반구의 활성화 값에 차이는 시각적 지시과제에 비해 청각적 지시과제가 높은 활성화 값을 보였다. 그러므로 언어영역에 대한 뇌의 기능적 영상을 얻는데 두 방법 모두 유용하다고 생각된다.

• 한국구조물진단유지관리공학회 논문집
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• 제24권6호
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• pp.67-76
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• 2020

본 논문은 철계-형상기억합금(Fe-SMA) 바를 이용하여 제작된 콘크리트 보의 휨 거동 평가를 위한 실험적 연구이다. 실험을 위해 200mm×300mm × 2,200mm의 콘크리트 보를 제작하였으며 인장재로 4% 사전변형된 Fe-SMA 바를 사용하였다. 실험 변수로 인장재 종류(SD400, Fe-SMA), 철근 비(0.2, 0.39, 0.59, 0.78), Fe-SMA 활성화(활성화, 비활성화) 그리고 Fe-SMA bar 연결방법(미연결, 용접, 커플러)를 고려하였다. Fe-SMA 바를 활성화하기 위해 전기저항 가열 방법을 이용하여 5A/㎟의 전류를 실험체가 160℃에 도달할 때 까지 공급하였다. 캠버효과에 의한 실험체의 상향 변위가 안정되면 2,000kN 용량의 엑츄레이터를 이용하여 3점 휨 재하 실험을 실시하였다. 실험결과 Fe-SMA 바를 활성화 함에 따라 캠버효과에 의해 상향 변위가 발생하는 것으로 나타났다. Fe-SMA 바를 활성화한 실험체는 활성화하지 않은 실험체에 비해 더 높은 하중에서 초기균열이 발생하였다. 그러나 일반적인 프리스트레스 콘크리트와 동일하게 Fe-SMA 활성화에 따른 프리스트레스 도입이 보의 극한 상태에 미치는 영향은 미미한 것으로 나타났다.

• 생명과학회지
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• 제25권10호
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• pp.1184-1195
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• 2015

새로운 실험 동물로 대두되고 있는 제브라피쉬는 척추동물 생식생물학 연구에서도 중요한 역할을 한다. 제브라피쉬의 난자 성숙은 maturation inducing hormone (MIH, 17α,20β-Dihydroxy-4-pregnen-3-one)에 의해 촉발된다. 대부분의 동물의 난자성숙에는 cdc2 kinase와 cyclinB 단백질 복합체인 MPF의 활성화가 필요하다. 발톱개구리와 생쥐에서는 MPF 활성이 두 가지 기작에 의해 조절되는데, 하나는 cyclinB 결합이고 또 다른 하나는 Wee1과 Cdc25에 의한 T14/Y15 잔기의 억제성인산화와 탈인산화이다. 발톱개구리나 생쥐와 달리 제브라피쉬를 포함한 대부분의 진골어류(teleost)는 GV 난자에 pre-MPF complex가 존재하지 않으므로 MPF 활성화는 전적으로 cyclinB 단백질의 de novo synthesis에 의존한다. 다른 종과 마찬가지로 제브라피쉬의 모계유래 mRNA도 CPEB, Dazl, Pum1/Pum2, insulin-like growth factor2 mRNA-binding protein 3 등 다양한 RNA binding protein (RBP)의 결합에 의해 번역이 조절된다. 그러나 제브라피쉬 난자에서 단백질 번역 조절에 관여하는 자세한 작용 기작은 확실하게 규명되지 않았다. 그러므로 제브라피쉬 난자의 성숙과정을 연구하는 것은 척추동물 난자 초기 성숙과정에서 단백질 번역 조절의 역할을 규명할 수 있는 새로운 정보를 제공할 것이다.

• BMB Reports
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• 제45권3호
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• pp.171-176
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• 2012

Receptor activator of NF-${\kappa}B$ ligand (RANKL) triggers the differentiation of bone marrow-derived monocyte/macrophage precursor cells (BMMs) of hematopoietic origin into osteoclasts through the activation of mitogen-activated protein (MAP) kinases and transcription factors. Recently, reactive oxygen species (ROS) and antioxidant enzymes were shown to be closely associated with RANKL-mediated osteoclast differentiation. Although glutaredoxin2 (Glrx2) plays a role in cellular redox homeostasis, its role in RANKL-mediated osteoclastogenesis is unclear. We found that Glrx2 isoform b (Glrx2b) expression is induced during RANKLmediated osteoclastogenesis. Over-expression of Glrx2b strongly enhanced RANKL- mediated osteoclastogenesis. In addition, Glrx2b-transduced BMMs enhanced the expression of key transcription factors c-Fos and NFATc1, but pre-treatment with SB203580, a p38-specific inhibitor, completely blocked this enhancement. Conversely, down-regulation of Glrx2b decreased RANKL- mediated osteoclastogenesis and the expression of c-Fos and NFATc1 proteins. Also, Glrx2b down-regulation attenuated the RANKL-induced activation of p38. Taken together, these results suggest that Glrx2b enhances RANKL-induced osteoclastogenesis via p38 activation.

• 대한한방부인과학회지
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• 제30권2호
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• pp.1-15
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• 2017

Objectives: The object of this study was to identify the anti-inflammatory effects of Patrinia scabiosaefolia aqueous extract (PSE). Methods: RAW 264.7 cells were pre-treated with PSE and then incubated with or without lipopolysaccharide (LPS). Cell viability, production of nitric oxide (NO), secretion of pro-inflammatory cytokine, activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-${\kappa}B$) were measured. In addition, we observed mice survival rate after LPS and their cytokine levels of serum. We also observed inflammatory and hemorrhagic change on the histological sections of the liver. Results: PSE inhibited LPS-induced NO production, interleukin (IL)-6 secretion, c-Jun NH2-terminal kinase (JNK) and NF-${\kappa}B$ activation. In addition, PSE reduced the death rate of LPS-induced mice and IL-6 production on the serum of mice. PSE inhibited inflammation and hemorrhage on liver tissue as well. Conclusions: The results suggest that PSE have anti-inflammatory effects by inhibited NF-${\kappa}B$ and JNK activation, IL-6 secretion, and NO production. So PSE may be effective treatment for the inflammatory disease.

• 한국수정란이식학회지
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• 제24권2호
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• pp.105-108
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• 2009

This study was designed to investigate the effect of kinetin on in vitro development of parthenogenetic porcine oocytes exposed to demecolcine prior to activation. In vitro matured metaphase II stage oocytes were incubated in 0 or 2 ${\mu}$g/ml demecolcine supplemented defined culture medium for 3 h and the oocytes were activated electrically. The parthenogenetic porcine embryos were then cultured in 0 or 200 ${\mu}$M kinetin supplemented defined culture medium for 7 days. Regardless of demecolcine treatment, kinetin supplementation increased blastocyst rates significantly (7.0% versus 12.1% and 4.9% versus 8.5%; Control versus Kinetin and Demecolcine versus Kinetin + Demecolcine, respectively, p<0.05). Demecolcine treatment before activation tended to decrease blastocyst rates regardless of kinetin supplementation although it is not statistically significant. Total cell numbers in the blastocysts also tended to be elevated in embryos when supplemented with kinetin, however only the result between Kinetin and Demecolcine groups is statistically significant (37.6 ${\times}$ 7.2 versus 28.1 ${\times}$ 9.5, respectively, p<0.05). In conclusion, the present report shows that kinetin enhances developmental competence of parthenogenetic porcine embryo regardless of demecolcine pre-treatment before parthenogenetic activation when they were developed in defined culture condition.

• 한국재료학회지
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• 제11권6호
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• pp.508-511
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• 2001

사파이어 단결정의 취성-연성전이에 대한 실험을 행하였다. 사파이어 단결정의 취성-연성전이온도는 변형율 3.3$\times$ $10^{-5}$/sec에서 $1000\pm$$25^{\circ}C$ 그리고 변형률 3.3$\times$$10^{-5}$/sec에서는 1100$\pm$26$^{\circ}C$이었다. 취성-연성전이모델을 이용하여 Prism Plane slip {1120} <1100> 전위속도의 활성화에너지를 계산하였으며, 그 결과 활성화에너지는 4.6$\pm$2.3eV의 범위를 가졌다. 이 활성화에너지는 에치-퍼트법을 이용하여 전위속도측정으로부터 구한 결과치 3.8eV와 유사하였다.

• Archives of Pharmacal Research
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• 제27권7호
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• pp.781-789
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• 2004

The effect of 1,8-cineole on cytochrome P450 (CYP) expression was investigated in male Sprague Dawley rats and female BALB/c mice. When rats were treated orally with 200, 400 and 800 mg/kg of 1,8-cineole for 3 consecutive days, the liver microsomal activities of benzy-loxyresorufin- and pentoxyresorufin-D-dealkylases and erythromycin N-demethylase were dose-dependently induced. The Western immunoblotting analyses clearly indicated the induction of CYP 2B1/2 and CYP 3A1/2 proteins by 1,8-cineole. At the doses employed, 1,8-cineole did not cause toxicity, including hepatotoxicity. Subsequently, 1,8-cineole was applied to study the role of metabolic activation in thioacetamide-induced hepatotoxicity and/or immunotoxicity in animal models. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 800 mg/kg of 1,8-cineole for 3 days, followed by a single intraperitoneal treatment with 50 and 100 mg/kg of thioacetamide in saline. 24 h later, thioacetamide-induced hepatotoxicity was significantly potentiated by the pretreatment with 1,8-cineole. When female BALB/c mice were pretreated with 800 mg/kg of 1,8-cineole for 3 days, followed by a single intraperitoneal treatment with 100 mg/kg of thioace-tamide, the antibody response to sheep red blood cells was significantly potentiated. In addition, the liver microsomal activities of CYP 2B enzymes were significantly induced by 1,8-cineole as in rats. Taken together, our results indicated that 1,8-cineole might be a useful CYP modulator in investigating the possible role of metabolic activation in chemical-induced hepato-toxicity and immunotoxicity.