• Title/Summary/Keyword: pre-activation

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A Study on the Influence of a Reflection Journal Upon Self Motivated-Learners' Study (성찰일지 적용이 이공계 자기주도학습 학생의 학업에 미치는 영향)

  • Kim, Hae-kyung;Kim, ChaJong
    • Journal of Engineering Education Research
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    • v.19 no.5
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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.

A study of Solid Phase Epitaxial Regrowth of Silicon using Laser Interferometry (Laser Interferometry를 이용한 Solid Phase Epitaxial Regrowth에 관한 연구)

  • Park, Se-Geun;Walser, R.M.
    • Proceedings of the KIEE Conference
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    • 1987.07a
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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.

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Functional MR Imaging of Language System : Comparative Study between Visual and Auditory Instructions in Word Generation Task (언어 중추 영역에 대한 기능적 자기공명영상: 시각적, 청각적 지시 과제에 관한 비교)

  • 구은회;권대철;김동성;송인찬
    • Journal of Biomedical Engineering Research
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    • v.24 no.4
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    • pp.241-246
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    • 2003
  • To evaluate the usefulness if functional MR imaging(MRI) for the determination of language dominance system and to assess differences in the visual and auditory instrument language generation task according to activation task or activated area. Functional maps of the language area were obtained during visual and auditory instructions in word generation tasks in 6 healthy volunteer with right-handness were examined on a 1.5T scanner and the EPI BOLD technique, and three pulse sequence technique get of the true axial planes. Both task consisted of 96 phases including 6 activations and rests contents. Postprocessing were done on MRDx program by using cross correlation method. Two task compare the blain activation area surveyed of 1anguage lateralization index. To evaluated of the detection rates of Broca. Wernicke, pre-frontal lobe, Supplementary Motor Area (SMA) and pre-motor cortex areas and the differences of language lateraliaztion among two word generation task To lateralization index survey in 1anguage area on right and left in brain get to activation area pixel in brain. Compared to visual and auditory instrument task in the language areas get to the lateralization index. Two language generation task high detection rates of Broca and Wernicke areas. The visual instruction no detected in the auditory area, and auditory instruction no detected in the visual area. There was statistics significant different of them among language generation task. 1'his indicated that language area obtained image of the brain functional MR imaging usefulness in the visual and auditory task instrument.

Flexural Behavior of Concrete Beams Reinforced with Fe based Shape Memory Alloy Bar (철계-형상기억합금 바로 제작된 콘크리트 보의 휨 거동)

  • Hong, Ki-Nam;Yeon, Yeong-Mo;Ji, Sang-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.67-76
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    • 2020
  • This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/㎟ was supplied until the specimen reached 160℃. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.

Oocyte Maturation Process of Zebrafish (Danio rerio), an Emerging Animal Model (새로운 실험 동물 모델인 제브라피쉬(Danio rerio)의 난자 성숙 기작)

  • Han, Seung Jin
    • Journal of Life Science
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    • v.25 no.10
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    • pp.1184-1195
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    • 2015
  • The zebrafish is an emerging vertebrate model organism in reproductive biology. The oocyte maturation of zebrafish is triggered by maturation inducing hormone (MIH, 17α,20β-Dihydroxy-4-pregnen-3-one). In almost all animals, the oocyte maturation is governed by activation of pre-MPF which consists of cyclinB and inactive Cdk1. In the oocyte of Xenopus and mice, the activity of Cdk1 is regulated in two ways, one is the interaction with cyclinB and the other is phosphorylation/dephosphorylation of T14/Y15 residues on the Cdk1 by Wee1 and Cdc25. Unlike Xenopus and mice that have a sufficient amount of pre-MPF, pre-MPF is absent in GV oocyte of most teleost including zebrafish. Therefore, the activation of MPF during zebrafish oocyte maturation might totally depend on de novo synthesis of cyclinB proteins. It is reported that the translation of maternal mRNA is regulated by combination of several RNA binding proteins such as CPEB, Dazl, Pum1/Pum2, and insulin-like growth factor2 mRNA-binding protein 3 in the zebrafish oocytes. However, the definitive mechanism of these proteins to regulate the translation of stored maternal mRNAs remains to be elucidated. Therefore, the investigation of the maturation process of the zebrafish oocyte will provide new information that can help identify the role of translational control in early vertebrate oocyte maturation.

Glutaredoxin2 isoform b (Glrx2b) promotes RANKL-induced osteoclastogenesis through activation of the p38-MAPK signaling pathway

  • Yeon, Jeong-Tae;Choi, Sik-Won;Park, Kie-In;Choi, Min-Kyu;Kim, Jeong-Joong;Youn, Byung-Soo;Lee, Myeung-Su;Oh, Jae-Min
    • BMB Reports
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    • v.45 no.3
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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.

Effects of Patrinia Scabiosaefolia Aqueous Extract on Cytokine and NF-κB Activation in LPS-induced RAW 264.7 Cells and Mouse (패장(敗醬) 물 추출물의 LPS로 유도된 RAW 264.7 세포와 mouse 염증모델에서 cytokine 및 NF-κB의 활성에 미치는 효과)

  • Ryu, Ik-Han;Cho, Hae-Joong;Song, Mi-Hwa;Choi, Chang-Min
    • The Journal of Korean Obstetrics and Gynecology
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    • v.30 no.2
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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.

Effect of Kinetin on In Vitro Development of Parthenogenetic Porcine Oocytes Exposed to Demecolcine Prior to Activation

  • Kim, Ki-Young;Park, Sang-Kyu;Roh, Sang-Ho
    • Journal of Embryo Transfer
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    • v.24 no.2
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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.

The Estimation of Activation Energy for Prism Plane SliP {1120} <1100> Dislocation Velocity in Sapphire Single Crystals using Brittle-to-ductile Transition Model (취성-연성 전이 model을 이용한 사파이어 단결정의 prism plane slip {1120} <1100> 전위속도에 대한 활성화에너지 계산)

  • Yun, Seog-Young;Lee, Jong-Young
    • Korean Journal of Materials Research
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    • v.11 no.6
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    • pp.508-511
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    • 2001
  • Experimental studies of the brittle-ductile transition (BDT) for pre-cracked sapphire single crystals were carried out. The BDT temperature in sapphire single crystals were $1000\pm$$25^{\circ}C$ and 1100$\pm$$25^{\circ}C$ at constant strain rate 3.3$\times$$10^{-5}$/sec and 3.3$\times$$10^{-6}$/sec, respectively. With aid of the BDT model, the activation energy for prism plane slip {1120} <1100> dislocation velocity was in the range of 4.6$\pm$2.3eV This activation energy for dislocation velocity with BDT model was compatible with the result of the dislocation velocity (3.8eV) using the etch-pit techniques.

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Pretreatment with 1,8-Cineole Potentiates Thioacetamide-Induced Hepatotoxicity and Immunosuppression

  • Kim, Nam-Hee;Hyun, Sun-Hee;Jin, Chun-Hua;Lee, Sang-Kyu;Lee, Dong-Wook;Jeon, Tae-Won;Lee, Jae-Sung;Chun, Young-Jin;Lee, Eung-Seok;Jeong, Tae-Cheon
    • Archives of Pharmacal Research
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    • v.27 no.7
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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.