• Proceedings of the PSK Conference
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• 2002.10a
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• pp.287.1-287.1
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• 2002

To study the expressions of glutamate transporter subtypes in cerebellar astrocytes following the chronic exposure of nicotine from mating, rats were treated with nicotine (25 ppm) from the beginning of mating through drinking water. After delivery. each group was divided into two groups. Groups were exposed to either distilled water or nicotine. From 7 day-old pups at each group. cerebellar astrocytes were prepared. Ten days after culture. the expressions of glutamate transporter subtypes (GLAST and GLT-1) were determined using immunochemistry and immunoblot. (omitted)

• IMMUNE NETWORK
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• v.9 no.6
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• pp.248-254
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• 2009

[ $TGF-{\beta}1$ ]is well known to induce Ig germ-line ${\alpha}$ ($GL{\alpha}$) transcription and subsequent IgA isotype class switching recombination (CSR). Homeodomain protein TG-interacting factor (TGIF) and E3-ubiquitin ligases TGIF interacting ubiquitin ligase 1 (Tiul1) are implicated in the negative regulation of $TGF-{\beta}$ signaling. In the present study, we investigated the roles of Tiul1 and TGIF in $TGF{\beta}1$-induced IgA CSR. We found that over-expression of Tiul1 decreased $TGF{\beta}1$-induced $GL{\alpha}$ promoter activity and strengthened the inhibitory effect of Smad7 on the promoter activity. Likewise, overexpression of TGIF also diminished $GL{\alpha}$ promoter activity and further strengthened the inhibitory effect of Tiul1, suggesting that Tiul1 and TGIF can down-regulate $TGF{\beta}1$-induced $GL{\alpha}$ expression. In parallel, overexpression of Tiul1 decreased the expression of endogenous IgA CSR-predicitive transcripts ($GLT_{\alpha},\;PST_{\alpha},\;and\;CT_{\alpha}$) and $TGF{\beta}1$-induced IgA secretion, but not $GLT_{\gamma3}$ and IgG3 secretion. Here, over-expressed TGIF further strengthened the inhibitory effect of Tiul1. These results suggest that Tiul1 and TGIF act as negatively regulators in $TGF{\beta}1$-induced IgA isotype expression.

• Molecules and Cells
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• v.24 no.2
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• pp.283-287
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• 2007

$TGF-{\beta}1$ induces Ig germ-line ${\alpha}$ ($GL{\alpha}$) transcription and subsequent class switching recombination (CSR) to IgA. In the present study, we investigated the roles of two E3-ubiquitin ligases, Smurfs (HECT type) and Arkadia (RING finger type) on $TGF{\beta}1$-induced IgA CSR. We found that over-expression of Smurf1 and Smurf2 decreased $TGF{\beta}1$-induced $GL{\alpha}$ promoter activity and strengthened the inhibitory effect of Smad7 on the promoter activity. Further, over-expression of Smurf1 and Smurf2 decreased both Smad3/4-mediated and Runx3-mediated $GL{\alpha}$ promoter activities, suggesting that the Smurfs can down-regulate the major $TGF-{\beta}1$ signaling pathway and decrease $GL{\alpha}$ gene expression. In parallel, the over-expressed Smurf1 decreased the expression of endogenous IgA CSR-predictive transcripts ($GLT_{\alpha}$, $PST_{\alpha}$, and $CT_{\alpha}$) and also $TGF{\beta}1$-induced IgA secretion. Conversely over-expression of Arkadia abolished the inhibitory effect of Smad7 on $TGF{\beta}1$-induced $GLT_{\alpha}$ expression and IgA secretion. Similar results were obtained in the presence of over-expressed Smad7 and Smurf1. These results indicate that Arkadia can amplify $TGF{\beta}1$-induced IgA CSR by degrading Smad7, which interacts with Smurf1. We conclude that Smurf and Arkadia have opposite roles in the regulation of $TGF{\beta}1$-induced IgA isotype expression.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.2
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• pp.185-192
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• 2016

Ampicillin, a ${\beta}$-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ischemia, ampicillin (200 mg/kg, intraperitoneally [i.p.]) or penicillin G (6,000 U/kg or 20,000 U/kg, i.p.) was administered daily for 5 days. The pretreatment with ampicillin but not with penicillin G significantly attenuated neuronal damage in the hippocampal CA1 subfield. Mechanistically, the increased activity of matrix metalloproteinases (MMPs) following forebrain ischemia was also attenuated by ampicillin treatment. In addition, the ampicillin treatment reversed increased immunoreactivities to glial fibrillary acidic protein and isolectin B4, markers of astrocytes and microglia, respectively. Furthermore, the ampicillin treatment significantly increased the level of glutamate transporter-1, and dihydrokainic acid (DHK, 10 mg/kg, i.p.), an inhibitor of glutamate transporter-1 (GLT-1), reversed the neuroprotective effect of ampicillin. Taken together, these data indicate that ampicillin provides neuroprotection against ischemia-reperfusion brain injury, possibly through inducing the GLT-1 protein and inhibiting the activity of MMP in the mouse hippocampus.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.313-316
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• 2000

원어민이 발성한 영어유음 시료를 사용하여 한국인 영문과와 타학과(비 영문과) 학생들을 대상으로 인지실험을 하였고, 시료의 정확성을 확인하기 위하여 원어민을 또 하나의 피험자 그룹으로 선택하였다. 영문과 피험자의 영어유음 인지결과를 살펴보면 어두$(70\%)$ < 어말$(75\%)$ < 어중$(80\%)$ glt; 연속음$(86\%)$의 순서로 인지율이 높아졌다. 타학과 피험자의 영어유음 인지에서는 어두$(59\%)$< 어말$(66\%)$ glt; 어중$(70\%)$ < 연속음$(72\%)$의 순서로 인지율의 증가를 보였다. 원어민의 영어유음 인지에서는 녹음에 참가하지 않은 다른 원어민을 대상으로 해서 총 평균 $99.6\%$로 거의 완벽한 인지율을 보였다. 그 만금 녹음된 시료가 정확하다는 것을 확인시켜 주었다. 피험자별 그룹에 대한 결과 비교에서는 원어민이 녹음한 발음으로 인지실험을 할 때 타학과$(66.8\%)$ < 영문과$(77.4\%)$< 원어민$(99.6\%)$의 순서로 점차 좋은 인지율을 보였다. 한국인이 발성한 영어유음에 대한 원어민의 인지실험에서는 한국인 영어유음 발음의 정확성을 알아보고자 하는 것이 목적이다. 한국인 발성시료에 대한 원어민의 총인지율은 $68\%$로 원어민의 발성시료에 대한 인지율 $99.6\%$와 비교해볼 때 영문과 녹음자들의 발음 정확도가 높지 못하다는 것을 보여 주었다. 평균/1/ $(79\%)$과 평균/r/$(58\%)$의 인지율을 보게 되면 한국인의 영어유음 발성에 있어서 /r/의 발성이 /1/의 경우보다 문제가 더 심각하다는 것을 알 수 있다. 특히 실험결과는 어두/1/$(87\%)$과 어두/r/$(43\%)$에서 뚜렷한 인지율의 차이를 보여주고 있다.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.190-194
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• 2002

Expression of Bacillus subtilis glutamyl-tRNA synthetase (GluRS) in Escherichia coli is lethal for the host, probably because this enzyme misaminoacylates ${tRNA_l}^{Gln}$ with glutamate in vivo. In order to overexpress B. subtilis GluRS, encoded by the gltX gene, in E. coli, this gene was amplified from B. subtilis 168 chromosomal DNA using PCR method and the entire coding region was cloned into a pET11a expression vector so that it was expressed under the control or the T7 Promoter. The resulting recombinant pEBER plasmid was transformed into E. coli Novablue (DE3) bearing the T7 RNA polymerase gene for expression. After IPTG treatment, the overproduced enzyme was purified using ammonium sulfate fractionation, Source Q anion exchange chromatography, Superdex-200 gel filtration, and Mono Q anion exchange chromatography. The purified enzyme yielded 18-fold increase in specific activity over the crude cell extract and its molecular weight was approximately 55 kDa on SDS-PAGE.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.1
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• pp.1-9
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• 2004

Inertial navigation system with hardware redundancy must use FDI(Fault Detection and Isolation) method to remove the influence of faulty sensors. Until now, several FDI methods such as PSA(Parity Space Approach), GLT(Generalized Likelihood ratio Test) and OPT(Optimal Parity vector Test) method are generally used. However, because these FDI methods only consider the situation that the system has one faulty sensor, these methods cannot be directly adapted for the system with two faulty sensors. To solve this problem, in this paper, PSA method is analyzed and based on this result, new FDI method called EPSA is proposed to consider a detection and an isolation of two faulty sensors in inertial navigation system.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.343-349
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• 2017

This study was conducted to investigate the residual level and the amount of transfer to lettuce grown in field condition treated with the 5-methyl-1,2,4-triazolo[3,4-b][1,3]benzothiazole (Azoxystrobin). The field trials on lettuce were carried out at two different green houses located in Gwangju (Field 1) and Yongin (Field 2). Soil and lettuce samples were collected at different days after soil treatment of azoxystrobin with two different concentrations, respectively. Average recoveries for azoxystrobin ranged from 86.9 to 113.6% from soil and lettuce with the variation coefficient of 0.1-4.6%. The initial concentrations of azoxystrobin in Gwangju soil were 9.20, 11.00 mg/kg and decreased to 1.36, 2.70 mg/kg at 43 DAT (days after treatment) in field 1, while 1.06, 2.23 mg/kg decreased to 0.20 and 0.67 mg/kg at 36 DAT in field 2, respectively. The half-lives of azoxystrobin were about 19.4 and 23.3 days for the low and high concentration of azoxystrobin treated soils in field 1 and 11.5 and 17.8 days in field 2 soils, respectively. Residue levels of azoxystrobin in lettuce were not detected in filed 1 and field 2 soils, respectively.

• Language and Information
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• v.4 no.1
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• pp.43-65
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• 2000

Along with the flourishign development of computational linguistics, research on the meanings of individual words has started to resume. Polyusemous words are especially brought into focus since their multiple senses have placed a real challenge to linguists and computer scientists. This paper mainly concerns the following three questions with regard to the treatments of such polysemous nouns and verbs in English and Korean. Firstly, what types of information should be represented in individual lexical entries for those polysemous words\ulcorner Secondly, how different are corresponding polysemous lexical entries in both languages\ulcorner Thirdly, what does a mental lexicon look like with regard to polysemous lexical entries\ulcorner For the first and second questions, Pustejosky's (1995) Generative Lexicon Theory (hereafter GLT) will be discussed in detail: the main focus falls on developing alternative way of representing (polysemous) lexical entries. For the third question, a brief discussion is made on mapping between concepts and their lexicalizations. Furthermore, a conceptual graph around conept 'bake' is depicted in terms of Sowa(2000)

• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.57-62
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• 2006

Composite thin-walled members for civil engineering application are mainly produced by pultrusion technique, and they are generally made of a polymeric resin system reinforced by E-glass fibers due to economical reason. This material combination results in low elastic moduli of the composite materials and makes the design of composite members to be governed by stability limit state. Therefore the buckling behavior of composite thin-walled members was experimentally investigated in the present study. Axial compression was applied on each specimens by a hydraulic ram and knife edge fixtures were placed at both ends to simulate simple boundary condition. Axial compression, lateral displacements and twisting at the mid-height of each specimen were measured by a set of transducers during buckling test. The experimental buckling loads were compared with analytical results obtained through isotropic formulas. In the calculation of analytical results, elastic properties such as Young's modulus(E) and shear modulus(G) were replaced with EL and GLT obtained from coupon tests, respectively.