• The Korean Journal of Physiology and Pharmacology
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• v.15 no.2
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• pp.107-114
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• 2011

Neurofibrillary tangle (NFT) is a characteristic hallmark of Alzheimer's disease. GSK3β has been reported to play a major role in the NFT formation of tau. Dysfunction of autophagy might facilitate the aggregate formation of tau. The present study examined the role of GSK3${\beta}$-mediated phosphorylation of tau species on their autophagic degradation. We transfected wild type tau (T4), caspase-3-cleaved tau at Asp421 (T4C3), or pseudophosphorylated tau at Ser396/Ser404 (T4-2EC) in the presence of active or enzyme-inactive GSK3${\beta}$. Trehalose and 3-methyladenine (3-MA) were used to enhance or inhibit autophagic activity, respectively. All tau species showed increased accumulation with 3-MA treatment whereas reduced with trehalose, indicating that tau undergoes autophagic degradation. However, T4C3 and T4-2EC showed abundant formation of oligomers than T4. Active GSK3${\beta}$ in the presence of 3-MA resulted in significantly increased formation of insoluble tau aggregates. These results indicate that GSK3${\beta}$-mediated phosphorylation and compromised autophagic activity significantly contribute to tau aggregation.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.118-118
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• 2011

The Nano-Floating Gate Memory(NFGM) devices with ZnO:Cu thin film embedded in Al2O3 and AlOx-SAOL were fabricated and the electrical characteristics were evaluated. To further improve the scaling and to increase the program/erase speed, the high-k dielectric with a large barrier height such as Al2O3 can also act alternatively as a blocking layer for high-speed flash memory device application. The Al2O3 layer and AlOx-SAOL were deposited by MLD system and ZnO:Cu films were deposited by ALD system. The tunneling layer which is consisted of AlOx-SAOL were sequentially deposited at $100^{\circ}C$. The floating gate is consisted of ZnO films, which are doped with copper. The floating gate of ZnO:Cu films was used for charge trap. The same as tunneling layer, floating gate were sequentially deposited at $100^{\circ}C$. By using ALD process, we could control the proportion of Cu doping in charge trap layer and observe the memory characteristic of Cu doping ratio. Also, we could control and observe the memory property which is followed by tunneling layer thickness. The thickness of ZnO:Cu films was measured by Transmission Electron Microscopy. XPS analysis was performed to determine the composition of the ZnO:Cu film deposited by ALD process. A significant threshold voltage shift of fabricated floating gate memory devices was obtained due to the charging effects of ZnO:Cu films and the memory windows was about 13V. The feasibility of ZnO:Cu films deposited between Al2O3 and AlOx-SAOL for NFGM device application was also showed. We applied our ZnO:Cu memory to thin film transistor and evaluate the electrical property. The structure of our memory thin film transistor is consisted of all organic-inorganic hybrid structure. Then, we expect that our film could be applied to high-performance flexible device.----못찾겠음......

• Journal of Pharmaceutical Investigation
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• v.39 no.4
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• pp.309-314
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• 2009

An enzyme immunoassay (EIA) was validated for quantitation of cacitriol in human plasma. Calcitriol was immunoextracted with immunocapsules, which contain monoclonal antibodies to calcitriol linked to solid phase particles in suspension with a vitamin D binding protein inhibitor. Calcitrol was eluated and the eluates were evaporated under a gentle stream of nitrogen gas. The absorbance of analytes was determined using a microplate reader (reference wavelength 650 nm; measurement wavelength 450 nm). The method was specific and sensitive enough to detect as low as 6.5 pmol/L of calcitriol. Linear calibration range was 6.5-491 pmol/L with correlation coefficient greater than 0.99. The overall accuracy was in the range of 83.8 to 111.2% and precision C.V. (%) 0.99 to 8.47%. The recovery was approximately 100% and stability was confirmed during storage and sample preparation. The pharmacokinetic parameters were calculated by baseline subtraction because calcitriol is an endogenous material. Following oral dose of calcitriol, the mean AUC$_{24h}$ was 1038${\pm}$539 pmol/Lhr and C$_{max}$ of 128${\pm}$63.1 pmol/L was reached at 3.50${\pm}$1.07 hr. The mean t$_{1/2}$ of calcitriol was 5.13${\pm}$2.10 hr. The present EIA method was successfully applied to study bioavailability after oral administration of 2 ${\mu}$g of calcitriol in healthy Korean subjects.

• Journal of Embryo Transfer
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• v.9 no.2
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• pp.197-205
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• 1994

This experiment was carried out to clarify the pedigree identification from blood typing of 301 Hoisteins in National Animal Breeding Institute(N.A.B.I.). Twenty kinds of standard reagent standardized by Insternational Society for Animal Blood Group Research provied from KNC improvement center, N, L, C, F. were used as the reference reagents in this study. The highest frequency of antigenic facfors was obtained from X$_2$in blood typing of 301 Holsteins. The frequency of X$_2$ was 0.714.In A blood system, four kinds of phenogroups were observed. The gene frequencies of Al and Z' phenogroups were equally 0.027.This frequency was greatly lower than those of breeds of Southern European and Zebu cattle. In B blood Systern, nineteen kinds of blood type were appeared. The appearance frequency of Gx blood type was 0.259, whish was higher than the others. In C blood system, thirty kinds of blood type were observed. The appearance frequency of X$_2$ blood type was the highest(0.189). In F blood system, three kinds of alleles were detected. The gene frequency of F allele was higher than that of V(0.105). However, the frequency of F allele(0.327) was greatly lower than that of "- /- " allele. In S blood system, twelve kinds of blood type were appeared and showed sirnilar appearance frequencies except " - / - " allele. From the results of the pedigree identification from 8 sires and 28 progenies of them, the accuracy of pedigree identification was 92.9%.ification was 92.9%.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.69.1-69.1
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• 2018

산업 현장에서 자주 사용되는 알루미늄 합금은 순도가 높은 알루미늄에 비해 경제성, 기계적 성질이 우수한 장점이 있다. 하지만 이런 합금들은 물리적, 화학적 성질이 순수 알루미늄과 달라 양극산화와 같은 표면처리가 쉽지 않다. 양극산화는 표면처리 기술의 대표적인 방법 중 하나로 인위적으로 산화피막을 형성하는 기술이다. 순도가 높은 알루미늄은 산성 전해질에서의 양극산화를 통해 다공성 산화피막을 형성할 수 있으며 그 구조로 인해 내식성, 내마모성 등 기계적, 화학적인 다양한 장점이 있다. 하지만, Mg, Si, Cr과 같은 성분이 함유된 알루미늄의 경우 산성 전해질에서 산화물을 형성되지 않는다. 본 연구에서 기존의 산성 전해질에서의 양극산화 방법이 아닌$K_2HPO_4$를 함유하는 고온의 글리세롤 전해질을 사용하여 양극산화를 진행하였다. 사용한 알루미늄은 산업용으로 자주 사용되는 3000계열의 알루미늄을 사용하였으며 균일한 양극산화를 위해 샌드페이퍼를 통한 연마과정을 통해 표면을 평탄화 하였다. 이후 전기화학적 에칭 과정을 거쳐 표면에 있는 자연산화막을 제거하여 표면 분석을 용이하게 하였다. 양극산화는 10wt%의 $K_2HPO_4$/글리세롤 전해질에서 전해질의 온도와 인가 전압을 달리 하여 진행하였다. 결과 $150^{\circ}C$ 이상의 온도에서 알루미늄 합금의 양극산화를 확인할 수 있었고 $170^{\circ}C$의 온도에서 인가 전압을 20V로 하였을 때 가장 정렬된 다공성 구조를 얻을 수 있었다. 본 연구 결과를 통해 산업용 알루미늄 합금의 양극산화를 통해 다공성 나노구조 산화물을 형성 시킬 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.453-453
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• 2013

유기 태양전지는 저비용으로 제작이 가능하고 제작이 용이한 장점을 가지고 있으므로 많은 그룹에서 관심을 가지고 있다. 정공 수송층으로 사용되는 PEDOT:PSS는 많이 사용되지만 강한 산성 특성 때문에 ITO 전극에 식각이 되므로 문제가 있다. 그러므로 산화물 반도체 $WO_3$, $MoO_3$, 그리고 $V_2O_3$ 등이 태양전지에 많이 만들어지고 있다. 특히 copper oxide는 높은 광흡수율을 가지고 있으므로 태양전지에 사용하는 데 많은 기대되는 물질이다. Copper oxide 박막은 열증착 법, 스프레이 필로시스, 전기화학 증착, 화학증착법, 그리고 솔-젤법 등 다양한 증착 방법이 있다. 넓은 면적의 소자를 제작할 경우 솔-젤 방법은 기존의 증착법에 비해 낮은 비용으로 제작, 높은 성장율, 그리고 높은 기계적 탄력성의 장점이 있다. 솔-젤법으로 만든 copper oxide는 P3HT의 HOMO (high occupied molecular orbital)와 비슷한 위치에 접하고 있으므로 정공수송층으로 적합하다. 본 연구에서 제작된 태양전지의 구조는 ITO/P3HT:PCBM/CuxO로 구성되어 있다. ITO가 $10{\Omega}$/sq의비저항을 가지고 있었고 UV 처리를 하였다. 그 위에 P3HT:PCBM (1:0.8 weight)를 스핀 코팅하였다. 마지막으로 0.1 M $Cu_xO$용액은 Cu (II) acetate monohydrate를 소스로 2-methoxyethanol ($C_3H_8O_2$)의 용제와 안정제로 monoethanolamine ($C_2H_7NO$)을 섞어서 만들었다. 그리고 P3HT:PCBM 위에 스핀 코팅하였고 열증착 방법으로 전극인 Ag 을 증착하여 최종 소자를 만들었다. Cu(II) acetate의 소스로 제작된 박막의 투과율 측정을 통해 에너지 밴드갭을 구할 수 있었다. Copper oxide 박막은 다결정구조 이므로 다중 밴드갭으로 구성되어지는 것을 알 수 있었다. 최종적으로 만들어진 소자를 열처리를 통해 소자 특성을 조사했더니 250도에서 가장 좋은 결과를 얻을 수 있었다.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.54-60
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• 2007

이 논문에서는 게이트 절연막 위에 vapor deposition polymerization(VDP)방법을 사용하여 성막한 유기 점착층을 진공 열증착하여 유기 박막 트랜지스터(OTFTs)소자를 제작할 수 있음을 증명하였다. 우리가 제작한 Staggered-inverted top-contact 구조를 사용한 유기 박막 트랜지스터는 전기적 output 특성이 포화 영역안에서는 포화곡선을, triode 영역에서는 비선형적인 subthreshold를 확실히 볼 수 있음을 발견했다. $0.2{\mu}m$ 두께를 가진 게이트 절연막위에 유기 점착층을 사용한 OTFTs의 장 효과 정공의 이동도와 문턱전압, 그리고 절멸비는 각각, 약 0.4cm2/Vs, -0.8V, 106 이 측정되었다. 게이트 절연막의 점착층으로써 폴리이미드의 성막을 위해, 스핀코팅 방법 대신 VDP 방법을 도입하였다. 폴리이미드 고분자막은 2,2bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA)와 4,4'-oxydianiline(ODA)을 고진공에서 동시에 열 증착 시킨 후, 그리고 $150^{\circ}C$에서 1시간, 다시 $200^{\circ}C$에서 1시간 열처리하여 고분자화된 막을 형성하였다. 그리고 점착층이 OTFTs의 전기적 특성에 주는 영향을 설명하기 위해 비교 연구하였다.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.210-220
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• 2004

The purpose of this study is to propose the raw data of conservation and restoration by analyzing the environmental and growth characteristics in Abeliophyllum distichum habitats. The types of soil were sandy loam, loam and silty clay loam and the correlation on chemical characteristics of soil appeared that T-N and C.E.C were highly correlative. In case of growth characteristics, height and diameter in 1st site, crown in 2nd site, number of leaves in 5th site and number of seeds in 4th site were better than other sites. In the results of correlation on growth characteristics, height and diameter were highly correlative. In case of growth and chemical characteristics, EC and height were highly correlative. In the results of regression analysis, R-square of height and EC was some 70.4％ and that of number of leaves and T-N was some 70.2%. To conserve and restore Abeliophyllum distichum habitats, there were demanded that the accurate environmental analysis that considered such diverse factors as light intensity, temperature, genetic quality and so forth.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.25-31
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• 1973

1. According to the slope (N., S., E., and W.), some ecological studies of shrubs to the southwestern Mojave Desert were analyzed from December 10 to December 12, 1971. 2. The order of important values in studied area were as follows; Liycum andersonii, Larrea, Ephedra, Franseria, etc. 3. Important values of Lycium in the south-slope showed more than that of the other slope. It was occupied over a half of important values. 4. Vegetation are very simple and the plants appeared among 35 quadrats ($1m^2$) in tested area are found to be 10 species and number of 40 individuals. 5. The differences of flora in each facing slope have not been observed. 6. The similarity of slope plants was measured by the Importance Value Index Community Coefficient (I.V.I.C.C.). According to IVICC, each slope plants showed higher value (87%) 7. Common species of each slope appeared 7 as follows; Lycium, Larrea, Ephedra, Franseria, Eriogonum, Yucca and Aster etc.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.186-189
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• 2003

The role of excess Pb about the crystallization behavior and electrical properties in b(Zr$\sub$0.52/Ti$\sub$0.48/)O3(PZT) thin films has not been precisely defined. In this work, the effect of excess Pb content on the ferroelectric properties of these films was investigated. To analyze the effect, PZT films containing various amounts of excess Pb were Prepared. PZT thin films were deposited on the Pt/Ti bottom electrode by rf magnetron sputtering method and then they were crystallized by rapid thermal annealing (RTA). The experiment showed that all PZT films indicated perovskite polycrystalline structure with preferred orientation (111) and no pyrochlore phase was observed. As higher excess Pb was included, the films showed that value of leakage current shift from 2.03${\times}$10$\^$-6/ to 6.63 ${\times}$ 10$\^$-8/A/cm$^2$ at 100kV/cm, and value of remanent polarization shift from 8.587 ${\mu}$C /cm$^2$ to 4.256 ${\mu}$C/ cm$^2$. Electrical properties of PZT thin film affected by Pb excess content of target were explained to be caused of defect among space charges and defect grain boundaries.