Cu 기판위에 성장한 MgO, MgAl₂O₄와 MgAl₂O₄/MgO 박막의 집속이온빔을 이용한 스퍼터링수율 측정과 이차전자방출계수 측정

정강원(K. W. Jung),이혜정(H. J. Lee),정원희(W. H. Jung),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.4

MgAl₂O₄ 막은 MgO 보호막 보다 단단하며 수분 흡착 오염문제에 상당히 강한 특성을 가진다. 본 연구에서 AC-PDP의 유전체보호막으로 사용되는 MgO 보호막의 특성을 개선하기 위해 MgAl₂O₄/MgO 이중층 보호막을 제작하여 특성을 조사하였다. 전자빔 증착기를 사용하여 Cu 기판에 MgO와 MgAl₂O₄을 각각 1000 Å 두께로 증착, MgAl₂O₄/MgO을 200/800 Å 두께로 적층 증착 후, 이온빔에 의한 충전현상을 제거하기 위해 Al을 1000 Å 두께로 증착하였다. 집속 이온빔(focused ion beam ; FIB)장치를 이용하여 10 ㎸에서 14 ㎸까지 이온빔 에너지에 따라 MgO는 0.364 ~ 0.449 값의 스퍼터링 수율에서 MgAl₂O₄/MgO을 적층함으로 24 ~ 30 % 낮아진 0.244 ~ 0.357 값의 스퍼터링 수율이 측정되었으며, MgAl₂O₄는 가장 낮은 0.088 ~ 0.109 값의 스퍼터링 수율이 측정되었다. g-집속이온빔(g-FIB)장치를 이용하여 Ne? 이온 에너지를 50 V에서 200 V까지 변화 시켜 MgAl₂O₄/MgO와 MgO는 0.09 ~ 0.12의 비슷한 이차전자방출 계수를 측정 하였다. AC-PDP셀의 72시간 열화실험 후 SEM 및 AFM으로 열화된 보호막의 표면을 관찰하여 기존의 단일 MgO 보호막과 MgAl₂O₄/MgO의 적층보호막의 열화특성을 살펴보았다. It is known that MgAl₂O₄ has higher resistance to moisture than MgO, in humid ambient MgO is chemically unstable. It reacts very easily with moisture in the air. In this study, the characteristic of MgAl₂O₄ and MgAl₂O₄/MgO layers as dielectric protection layers for AC-PDP (Plasma Display Panel) have been investigated and analysed in comparison for conventional MgO layers. MgO and MgAl₂O₄ films both with a thickness of 1000 Å and MgAl₂O₄/MgO film with a thickness of 200/800 Å were grown on the Cu substrates using the electron beam evaporation. 1000 Å thick aluminium layers were deposited on the protective layes in order to avoid the charging effect of Ga? ion beam while the focused ion beam(FIB)is being used. We obtained sputtering yieds for the MgO, MgAl₂O₄ and MgAl₂O₄/MgO films using the FIB system. MgAl₂O₄/MgO protective layers have been found th show 24 ~ 30% lower sputtering yield values from 0.244 up to 0.357 than MgO layers with the values from 0.364 up to 0.449 for irradiated Ga? ion beam with energies ranged from 10 ㎸ to 14 ㎸. And MgAl₂O₄ layers have been found to show lowest sputtering yield values from 0.88 up to 0.109. Secondary electron emission coefficient(g) using the γ-FIB. MgAl₂O₄/MgO and MgO have been found to have similar g values from 0.09 up to 0.12 for indicated Ne+ ion with energies ranged from 50 V to 200 V. Observed images for the surfaces of MgO and MgAl₂O₄/MgO protective layers, after discharge degradation process for 72 hours by SEM and AFM. It is found that MgAl₂O₄/MgO protective layer has superior hardness and degradation resistance properties to MgO protective layer.

O-GlcNAcylation of amyloid-β precursor protein at threonine 576 residue regulates trafficking and processing

Chun, Y.S.,Kwon, O.H.,Chung, S. Academic Press 2017 Biochemical and biophysical research communication Vol. No.

The pathological hallmark of Alzheimer's disease (AD) is associated with the accumulation of amyloid-β (Aβ) derived from proteolytic processing of amyloid-β precursor protein (APP). APP undergoes post-translational modification including N- and O-glycosylation. O-GlcNAcylation is a novel type of O-glycosylation, mediated by O-GlcNAc transferase attaching O-β-N-acetylglucosamine (O-GlcNAc) to serine/threonine residues of the target proteins. O-GlcNAc is removed by O-GlcNAcase. We have previously reported that increasing O-GlcNAcylated APP using the O-GlcNAcase inhibitor, PUGNAc, increases its trafficking rate to the plasma membrane and decreases its endocytosis rate, resulting in decreased Aβ production. However, O-GlcNAc modification sites in APP are unknown. In this study, we mutated three predicted O-GlcNAc modification threonine residues of APP into alanines (T291A, T292A, and T576A) and expressed them in HeLa cells. These APP mutants showed reduced O-GlcNAcylation levels, indicating that these sites were endogenously O-GlcNAcylated. Thr 576 was the major O-GlcNAcylation site when cell was treated with PUGNAc. We also showed that the effects of PUGNAc on APP trafficking to the plasma membrane and Aβ production were prevented in the T576A mutant. These results implicate Thr 576 as the major O-GlcNAcylation site in APP and indicate that O-GlcNAcylation of this residue regulates its trafficking and processing. Thus, specific O-GlcNAcylation of APP at Thr 576 may be a novel and promising drug target for AD therapeutics.

돼지 卵子의 透明帶에 대한 單一클론抗體生産과 그 特性에 關한 硏究

金鐘培,劉永春,金昌圭,權五中,鄭盛元,鄭吉生 건국대학교 동물자원연구센터 1991 動物資源硏究誌 Vol.16 No.-

本 試驗은 單一클론抗體의 강한 特異性과 抗體性質의 不變性을 이용하여 發生學的 側面에서 哺乳動物 卵子의 透明帶의 機能과 構造를 이해하고, 또한 種特異的인 精子 受容體의 存在 및 生化學的 構造를 규명하기 위한 기초연구로서, 돼지 卵子의 透明帶를 免疫原으로 하여 BABL/c 생쥐로부터 單一클론抗體를 생산하고 그 특성을 구명하였던 바 다음과 같은 결과를 얻었다. 1) 3마리의 BABL/c 생쥐(YⅠ, YⅡ, ZI)에 돼지卵子의 透明帶를 免疫化하고, 複合抗體 生成을 확인한 후 생쥐의 脾臟細胞와 Myeloma(SP2/O-Ag14)를 polyethylene glycol를 融合을 실시한 결과 각각 25.8%, 54.5% 그리고 59.7%의 融合效率을 나타내었으며, ELISQ에 의해 陽性反應을 조사한 결과 각각 17.3%, 32.6% 그리고 6.2% 陽性反應 效率을 나타내었다. 2) YI에서 강한 陽性反應을 보인 6개의 well에 대한 cloning을 실시하고 抗體檢證을 행한 결과 20.8% ∼ 48.4%의 Cloning效率과 54.6% ∼ 82%의 陽性反應 效率을 나타내었다. 3) 강한 陽性反應을 나타낸 항체에 대해 sandwich ELISA法에 의해 isotype을 決定하였던바 2E93C(YⅠ), 3E83E7(YⅠ), 4E3(YⅡ)각각 IgG₂b, IgG₂a, IgM으로 확인되었다. 4) Isotype이 決定된 2E93C9(YⅠ), 3E84E7(YⅠ), 4E3(YⅡ)의 세포를 생쥐의 腹腔에 주사하여 얻은 腹水를 indirect ELISA法에 의해 titer를 決定한 결과 모두 1:400,000 이상의 높은 titer를 나타내었다. 5) 處理區로서 單一클론抗體의 腹水와 對照區로서 normal mouse serum이 각각 2%씩 함유된 배양액속에서 난자를 배양한 후 顯徵鏡下에서 관찰했을 때 對照區에서 배양된 난자의 표면은 정상적인 형태를 나타냈으나 處理區에서 배양된 卵子는 표면에 뚜렷한 沈澱層을 형성하였다. 6) 處理區와 對照區 卵子를 Rabbit anti-mouse IgG-FITC가 1% 함유된 배양액속에서 배양하고 洗滌한 후 螢光顯徵鏡下에서 관찰한 바 處理區의 卵子는 透明帶 주위에서 螢光이 나타났으나, 對照區에서는 나타나지 않았다. This study was carried out ot produce and characterize monoclonal antibodies against porcine zona pellucida, and undertaken as a basic study to develop immunocontraceptive vaccine and to investigate the function of zana pellucida in early fertilization process. The results obtained were summarized as follows: 1. Spleen cells of three BALB/C mice(YⅠ, YⅡ and ZI) which were immunized with porcine zona pelucida were fused with myeloma cells(SP2/O-Ag14) by polyethylene glycol. At the result of fusion, fusion efficiency was 25.8 , 54.5% and 59.7% and positive efficiency 17.3%, 32.6% and 6.2%, respectively. 2. Cloning efficiency was shown to be from 20.8% to 48.4% and positive efficiency of them were 54.6% to 82%. 3. Sub-isotypes of three strong positive antibodies, 2E93C(YⅠ), 3E83E7(YⅠ) and 4E3(YⅡ) were determined by sandwich ELISA method and shown to be as IgG2b, IgH2a and IgM, respectively. 4. The titers of three ascitic fluids containing antibodies, 2E93C9(YⅠ), 3E84E7(YⅠ) and 4E3(YⅡ) were determined by indirect ELISA and all of them showed above 1:400,000. 5. The layer of precipitate was observed on the zona incubated with medium containing 2% ascitic fluid of monoclonal antibody while the eggs treated with 2% normal mouse serum did not. 6. Porcine eggs incubated with medium containing 2% ascitic fluid of monoclonal antibody and followed by subsequent incubation with Rabbit anti-mouse IgG-FITC conjugate showed strong fluorescent light on the zona surface while the zona of normal mouse serum-treated eggs did not show fluorescence.

Influence of Annealing Temperature on Magnetoelectric Properties of CoFe2O4/Pt/Pb(Zr0.3Ti0.7)O3 Thin Films

Eum, Y.J.,Hwang, S.-O.,Ryu, J.,Kim, J.-W.,Koo, C.Y.,Lee, J.-Y.,Lee, H.Y. Taylor Francis 2014 Ferroelectrics Vol.465 No.-

<P>CoFe2O4/Pt/Pb(Zr0.3Ti0.7)O-3 thin films were grown on Pt/Ti/SiO2/Si substrate in order to investigate the magnetoelectric properties of ferromagnetic/ferroelectric multilayer thin films. Thin Pt layer was introduced to prevent inter-diffusion between CoFe2O4 and Pb(Zr0.3Ti0.7)O-3 (PZT) layers. PZT thin film was grown directly on top of Pt substrate by utilizing sol-gel spin coating technique. In order to investigate the possible annealing effect on film microstructure and magnetoelectric properties, multilayer thin film stack was heat-treated at different temperatures ranging from 550 degrees C to 650 degrees C. The structural properties of the films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ferroelectric and ferromagnetic behaviors were analyzed by measuring polarization and magnetization - electric and magnetic field hysteresis. Magnetoelectric coefficients were calculated by measuring magnetoelectric voltages using magnetoelectric measurement system. Both the magnetoelectric properties and the coupling effect of CoFe2O4/Pt/PZT films on ferromagnetic and magnetoelectric properties are discussed as a function of heat-treatment temperature.</P>

Magnetoelectric Coupling of CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O3 Multilayer Thin Films

Hwang, S.-O.,Eum, Y.J.,Kim, J.-W.,Ryu, J.,Koo, C.Y.,Lee, J.-Y.,Lee, H.Y. Taylor Francis 2014 Ferroelectrics Vol.465 No.-

<P>CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O-3 (PZT) multilayer thin films were grown on (111)-oriented Pt/TiO2/SiO2/Si < 100 > substrate. PZT layer was fabricated by the sol-gel method. Afterwards, Pt layer was deposited by ion beam sputtering method. Finally, CuFe2O4 layer were deposited using pulsed laser deposition method (PLD). The film structure is tri-layered type, where the bottom PZT layer covered the whole substrate, while Pt and CuFe2O4 layers were deposited through circular shadow masks to measure ferroelectric and magnetoelectric properties. Film microstructure was observed using XRD and FE-SEM. Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using magnetoelectric measurement system.</P>

RF-O₂ Plasma 처리한 MgO 박막의 스퍼터링 수율 측정

정원희(W. H .Jeoung),정강원(K. W. Jeong),임연찬(Y. C. Lim),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),김윤기(Y. K. Kim),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.3

RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율을 집속이온빔 장치를 이용하여 측정하였다. 가속 전압 10 ㎸의 Ga 이온빔을 주사했을 때 plasma 처리하지 않은 MgO 박막의 스퍼터링 수율은 0.33 atoms/ion, RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율은 0.20 atoms/ion 으로 RF-O₂ plasma 처리한 경우 스퍼터링 수율이 낮아졌다. 또한 XPS, AFM을 통해 plasma 처리로 인한 MgO 표면의 변화를 관찰하였다. MgO 박막에 RF-O₂ plasma 처리 한 후 XPS O 1s spectra의 binding energy와 FWHM 값이 각각 2.36 eV와 0.6167 eV 작아졌고 표면거칠기의 RMS 값 또한 0.32 ㎚ 작아졌다. We measured sputtering yield of RF O₂-plasma treated MgO protective layer for AC-PDP(plasma display panel) using a Focused Ion Beam System(FIB). A 10 ㎸ acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 ㎚, respectively.

X-ray and Spectroscopy Studies of Mercury (II) and Silver (I) Complexes of α-Ketostabilized Phosphorus Ylides

K. Karami,O. Büyükgüngör,H. Dalvand 대한화학회 2011 대한화학회지 Vol.55 No.1

The complexation behavior of the α-ketostabilized phosphorus ylides Ph_3P=CHC(O) C_6H_4-X (X=Br, Ph) towards the transition metal ions mercury (II) and Silver (I) was investigated. The mercury(II) complex {HgX_2 [Y]} 2 (Y_1=4-bromo benzoyl methylene triphenyl phosphorane; X=Cl(1), Br(2), I(3), Y_2=4-phenyl benzoyl methylene triphenyl phosphorane; X=Cl(4), Br(5),I(6)) have been prepared from the reaction of Y_1 and Y_2 with HgX_2 (X=Cl, Br, I) respectively. Silver complexes [Ag(Y_2) _2]X(X=BF_4(7), OTf(8)) of the α-keto-stabilized phosphorus ylides (Y_2) were obtained by reacting this ylide with AgX (X=BF_4,OTf) in Me_2CO. The crystal structure of complexes (1) and (4) was discussed. These reactions led to binuclear complexes C-coordination of ylide and trans-like structure of complexes [Y_1HgCl_2]_2. CHCl_3 (1) and [Y_2HgCl_2]_2 (4) is demonstrated by single crystal X-ray analyses. Not only all of complexes have been studied by IR, ^1H and ^(31)P NMR spectroscopy, but also complexes 1-3 have been characterized by ^(13)CNMR.

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

MgAl₂O₄ 스피넬 내화물의 합성과 응용

이윤복,권상오,장윤식,박상희,오기동 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

MgO-Al₂O₃계에서 MgO첨가량에 따른 스피넬의 생성과 소결성을 조사하였다. 아울러 스피넬 내화물과 시멘트를 구성하는 주성분인 CaO의 반응성에 대하여 검토하였다. 가열된 시편의 상은 대부분의 스피넬, 페리클레이스 및 코런덤으로 동정되었고 과잉의 MgO를 함유한 시편의 경우 1750℃에서는 잔류 코런덤은 확인되지 않았다. MgO 함량이 감소함에 따라 스피넬내에 Al₂O₃의 고용에 기인된 스피넬의 생산량은 증가하는 경향을 나타내었다. 과잉의 MgO를 함유한 시편은 1600℃에서 치밀화가 촉진되어 1750℃, 5시간 유지한 시편의 경우 최종 소결밀도는 3.51g/㎤였다. 1750℃, 5시간 유지한 시편을 회전침식시험한 결과, 과잉의 MgO를 함유한 시편의 경우 침식깊이가 8.2mm, 침식면적이 225㎟로 다른 시편에 비교하여 가동면에서 CaO에 대한 침식저항성이 우수하였다. Effects of MgO content in spinel formation and sintering behavior of MgO-Al₂O₃ system were investigated. The reactivity of CaO in spinel refractories was also studied. From phase analyse, the refractories composed of mainaly two phase as like periclase and spinel, and residual corundom. However, the residual corundum was almost disappeared as it was fired at 1750℃ with excess of MgO. As the amount of MgO was reduced, the formation of spinel increased due to solid solubility of Al₂O₃ in spinel. The sample with excess of MgO markedly promoted the densification of spinel at 1600℃. The density of sample fired at 1750℃ for 5h was 3.51g/㎤. In rotary corrosion test, the sample with excess of MgO content, which had 8.2mm in the corrosion depth and 225㎟ in the corrosion area showed excellent corrosion resistance against the reactivity of CaO on the surface of spinel refractories.

대학생의 인터넷중독 및 스마트폰 중독 정도와 미술 치료 인식에 대한 조사 연구

박혜원,송승윤,윤하영,이경현,이소영,이지원,진예은,최시온,허은서,황다빈,신주현,이인영 이화여자대학교 간호학회 2018 이화간호학회지 Vol.- No.52

Purpose: Investigate the level of Internet and smart phone addiction of college students and difference of their perception on the art therapy. Method: Data was collected using 4 categories of questionnaires. Participants of this study were 383 college students who are currently attending universities located in seoul, Kyung-Ki and Incheon. The Chi-square test, One-way Analysis of Variance, Scheffé test were performed using IBM SPSS Statistics 23.0 Result: First, the study has established that the status of attending universities, grade, people who living with, age affected the level of Internet addiction of college students. In terms of the level of smart phone addiction of college students, the status of attending universities, gender, age were the affective factors. Second, there was a significant difference on the perception of the advantages of the art therapy and the level of acknowledging it, depending on the level of Internet addiction. Finally, depending on the level of smartphone addiction, there was a significant difference in the level of perception of the art therapy, expectation toward the art therapy and the helpfulness of art therapy. The more the participants are close to the addicted level, the more they want to experience the art therapy. Conclusion: These results suggest. First, it is necessary to use bigger group of participants. Second, it is necessary to improve the research methods for college students. Third, nurse should offer holistic care toward the patients regarding their general characteristics by adapting this study. Finally, it is necessary to improve the art therapy programs for the college students who are addicted to the Internet and smartphone and to develop researches proving the effectiveness of these programs.