• 제목/요약/키워드: Alternation

검색결과 386건 처리시간 0.027초

Calcium Signal Dependent Cell Death by Presenilin-2 Mutation in PC12 Cells and in Cortical Neuron from Presenilin-2 Mutation Transgenic Mice

  • Lee, Sun-Young;Song, Youn-Sook;Hwang, Dae-Yeun;Kim, Young-Kyu;Yoon, Do-Young;Lim, Jong-Seok;Hong, Jin-Tae
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2003년도 추계학술대회
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    • pp.145-145
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    • 2003
  • Familial form of Alzheimer's disease (FAD) is caused by mutations in presenilin-1 (PS-1) and presenilin-2 (PS-2). PS1 and PS2 mutation are known to similar effects on the production of amyloid ${\beta}$ peptide (A${\beta}$) and cause of neuronal cell death in the brain of patient of AD. The importance of the alternation of cellular calcium homeostasis in the neuronal cell death by PS1 mutation in a variety of experimental systems has been demonstrated.(omitted)

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공리적 설계를 이용한 초미세 발포 공정 설계

  • 정대진;차성윤;윤재동
    • 한국정밀공학회지
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    • 제18권1호
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    • pp.195-200
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    • 2001
  • There is a great demand for reducing the amount of material used in mass-produced plastics parts, for material cost constitutes up to 75% of the total production cost. Plastics do not easily decay which causes environmental problem. Furthermore, material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore, microcellular foamed plastics(MCPs) was developed at MIT to solve these problem alternation 1980's. Until now, however, microcellular foaming process not designed systematically because the key factors governing the process were not clear. The goal of this research is to obtain the optimal design of the microcellular plastics by using axiomatic approach.

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핸드폰 기기변경을 통한 해지방어 모델 개발 (The Model for Churn Defense using Alternation of Mobile-phone)

  • 서종현;장영순
    • 한국IT서비스학회:학술대회논문집
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    • 한국IT서비스학회 2006년도 추계학술대회
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    • pp.375-380
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    • 2006
  • 각 이동통신사들은 통화품질 수준이 비슷하게 유지 됨으로써 단말기 불만이 해지의 중요한 요소로 파악되고 있으며, 기기변경을 통해 고객의 이탈을 방지하는 전략을 펴고 있으며 이는 실제 상당한 효과가 있는 것으로 알려져 있다. 또한 2004년부터 시행된 번호이동성 도입으로 기기변경에 대한 캠페인이 중요한 이슈로 부각되고 있다. 따라서 이 연구에서는 고객 분석을 통해 기기변경에 대한 욕구가 높은 고객을 선별할 수 있는 모델을 수립하고 타겟된 고객을 기변 요인에 따라 그룹핑하여 개인화된 캠페인을 실시하는 방법을 제시하고자 한다. 기존의 regression, decision tree, neural networks 등을 이용하여 기변에 큰 영향을 미치는 변수들을 선별하고, 이를 바탕으로 캠페인 성공률을 높일 수 있는 고객을 선별하게 된다.

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천연 제올라이트의 물리화학적 성질 -경북 감포산 제올라이트에 관하여- (Physico-Chemical Properties of Natural Zeolite -On the Zeolite from Kampo Area-)

  • 조승래;이홍기;이주성;심미자;김상욱
    • 한국표면공학회지
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    • 제26권6호
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    • pp.334-340
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    • 1993
  • The physico-chemical properties and characteristics after thermal treatment of natural zeolite from Kampo area were studied. The physico-chemical properties of natural zeolite were studied by investigating chemical composition, x-ray diffraction pattern(XRD), scanning electronic microscope(SEM), infrared spec-tra(IR), thermal analysis(TA), and cation exchange capacity(C.E.C.), and the characteristics of natural zeo-lite after thermal treatment from $400^{\circ}C$ to $900^{\circ}C$ were compared with the natural zeolite. This study showed that clinoptilolite was the predominant costituent in natural zeolite, and the natural zeolite contained a little amount of quartz and feldspar as impurities. Zeolite mineral was seen to develop slowly by the natural alternation of volcanic ash considering the almost amorphous crystal structure. The more temperature of ther-mal treatment increased, the more adsorption capacity decreased, considering the fact that the hydroxy peak diminished on infrared spectra, and that cation exchange capacity also decreased distinctly.

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The Complementizer That-Deletion in English

  • Kim, Yangsoon
    • International Journal of Advanced Culture Technology
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    • 제9권3호
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    • pp.112-116
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    • 2021
  • The aim of this study is to analyze the complementizer that-deletion in embedded complement clauses in English. This paper is concerned with the alternation between the overt that-complementizer and the zero complementizer by the complementizer deletion (C-deletion or that-deletion) in constructions with a nominal complement that-clause, i.e. [VP Verb [CP that-TP]]. In this paper, we compare that-complementation and zero-complementation in a diachronic grammaticalization and corpus, and show that the complementizer that has its origin in pronouns diachronically and finally becomes to form a C-head of the functional category CP. We provide the syntactic and semantic explanation on the optionality of that-deletion while answering the question why and how that-deletion is getting increasing in use especially with the verb, think, in the informal contexts. With the major causes for the currently increasing use of that-deletion, we are concerned with the contexts in which the overt complementizers or the covert complementizers are preferred.

The Interaction of Mastoparan B from Venom of a Hornet Vespa Basalis with Phospholipid Matrices

  • 박남규;Yuhji Yamato;Sannamu Lee;Gohsuke Sugihara;박장수;강신원
    • Bulletin of the Korean Chemical Society
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    • 제17권3호
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    • pp.239-244
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    • 1996
  • Mastoparan B (MP-B) that is a novel MP isolated from the hornet Vespa basalis, was studied as compared with MP, in terms of interaction with phospholipid bilayer and antimicrobial activity. MP-B has more hydrophilic amino acid residues in hydrophilic face of amphiphilic α-helical structure than MP. The both peptides exhibited considerably different effect on interaction with lipid bilayers, e.g. their conformation in the presence of acidic and neutral liposomes, dye-release ability from encapsulated liposomes, but on the whole the interaction mode was similar. On antimicrobial activity, MP had a strong activity against Gram-positive bacteria but no against Gram negative ones. Contrary to this, MP-B had a strong activity against Gram-positive and potent against Gram-negative ones. Since both peptides have almost same residues on the hydrophobic side, such more hydrophilic surface on the molecule seems to lead to the subtle change in its interaction with membranes, resulting in the alternation in its biological activity.

Effects of a naturally derived surfactant on hydrate anti-agglomeration using micromechanical force measurement

  • Li, Mingzhong;Dong, Sanbao;Li, Bofeng;Liu, Chenwei
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.140-147
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    • 2018
  • The performance of a hydrate anti-agglomerant (AA) on cyclopentane (CyC5) hydrate anti-agglomeration at various concentrations (0-1 wt%, based on the oil phase) using MMF apparatus has been investigated. At low AA concentrations up to 0.01 wt%, the AA reduces the cohesion force (capillary force) by reducing the CyC5-water interfacial tension. At concentrations higher than 0.1 wt%, hydrate hydrophobicity alternation and AA's thermodynamic inhibition effects are the main part of AA's mechanism. Additionally, a "temporary agglomeration" phenomenon caused by surface melting of the hydrate particles is also observed, which may indicate the AA's weak ability to produce stable water-CyC5 interface.

Alternation of plasma $F_2$-isoprostanes before and after hemodialysis in patients with atherosclerosis in end-stage renal disease

  • Kim, Kyung-Mee;Jung, Byung-Hwa;Kim, Sang-Wook;Paeng, Ki-Jung;Chung, Bong-Chul
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.287.1-287.1
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    • 2003
  • F$_2$-isoprostanes are derived in vivo principally from the formation of positional peroxyl radicals of arachidonic acid, endocyclization to prostaglandin G$_2$-like structures, and reduction to PGF$_2$-like compounds. F$_2$-isoprostanes have been proposed as biomarkers of lipid peroxidation, oxidative stress status, and oxidation of low density lipoprotein (LDL) in atherogenesis. Especially, elevated 8-iso-PGF$\sub$2a/ is known as a useful clinical biomarker of oxidative stress in-end stage renal disease (ESRD) patients receiving hemodialysis (HD). (omitted)

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Studies of the functional roles of DRY motif in dopamine D2 and D3 receptors

  • Beom, Sun-Ryeo;Yang, Jee-Hyeo;Kim, Kyeong-Man
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.91.1-91.1
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    • 2003
  • Asparate-arginine-tyrosine (DRY) motif is highly conserved among GPCRs, and the alternation of this motif has been reported to exist naturally and involved with various diseases that involves constitutive activation or desensitization of receptor. To understand the interaction between G protein and ${\beta}$-arrestin more systemically, we produced the DHY mutants for the D2R and D3R. The introduction of R to H mutation in DRY motif caused differential effects on the characteristics of D2R and D3R: for both receptors receptor-effector coupling and (omitted)

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Calcium signal dependent cell death by presenlin-2 mutation in PC12 cells and in cortical neuron from presenlin-2 mutation transgenic mice

  • Lee, Sun-Young;Song, Yeun-Suk;Hwang, Dae-Yeun;Kim, Young-Kyu;Yoon, Do-Young;Lim, Jong-Seok;Hong, Jin-Tae
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.94.3-95
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    • 2003
  • Familial form of Alzheimer's disease (FAD) is caused by mutations in presenilin-l (PS-1) and presenilin-2 (PS-2). PS1 and PS2 mutation are known to similar effects on the production of amyloid peptide (A ) and cause of neuronal cell dath in the brain of patient of Alzheimer's disease. The importance of the alternation of cellular calcium homeostasis in the neuronal cell death by PS1 mutation in a variety of experimental systems has been demonstrated. However, no studies on the effect of PS2 of mutant PS2 on cellular calcium homeostasis, and relevance of its change to neuronal cell vulnerability against neurotoxins have been reported. (omitted)

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