Thickness-dependent electronic structure in ultrathinLaNiO3films under tensile strain

Yoo, Hyang Keun,Hyun, Seung Ill,Chang, Young Jun,Moreschini, Luca,Sohn, Chang Hee,Kim, Hyeong-Do,Bostwick, Aaron,Rotenberg, Eli,Shim, Ji Hoon,Noh, Tae Won American Physical Society 2016 Physical Review B Vol.93 No.3

<P>We investigated electronic-structure changes of tensile-strained ultrathin LaNiO3 (LNO) films from ten to one unit cells (UCs) using angle-resolved photoemission spectroscopy (ARPES). We found that there is a critical thickness t(c) between four and three UCs below which Ni e(g) electrons are confined in two-dimensional space. Furthermore, the Fermi surfaces (FSs) of LNO films below t(c) consist of two orthogonal pairs of one-dimensional (1D) straight parallel lines. Such a feature is not accidental as observed in constant-energy surfaces at all binding energies, which is not explained by first-principles calculations or the dynamical mean-field theory. The ARPES spectra also show anomalous spectral behaviors, such as no quasiparticle peak at the Fermi momentum but fast band dispersion comparable to the bare-band one, which is typical in a 1D system. As its possible origin, we propose 1D FS nesting, which also accounts for FS superstructures observed in ARPES.</P>

Insulating-layer formation of metallic LaNiO₃ on Nb-doped SrTiO₃ substrate

Yoo, Hyang Keun,Chang, Young Jun,Moreschini, Luca,Kim, Hyeong-Do,Sohn, Chang Hee,Sinn, Soobin,Oh, Ji Seop,Kuo, Cheng-Tai,Bostwick, Aaron,Rotenberg, Eli,Noh, Tae Won American Institute of Physics 2015 Applied Physics Letters Vol.106 No.12

색채조화의 이론적 연구

유근향 ( Keun Hyang Yoo ) 한국디자인과학학회 2002 디자인과학연구 Vol.5 No.3

최근 디자인, 미술계는 물론 산업의 각 분야에서 색채 관련 분야가 크게 부각되고 있는데, 이는 색채가 제품의 부가가치를 더해주기 때문이며, 컬러를 중시하는 변화 된 사회풍조와 소비자들의 다양화 된 생활패턴이 생활의 질과 문화적 가치를 추구하는 현상으로 나타나고 있기 ??문이다. 그러므로 더 이상 컬러를 색채로만 해석해서는 안 된다. 즉, 색을 사용하는 사용자의 입장이 고려되지 않은 채 단순히 치장하는 개념의 색이 아니라 학문적, 기술적으로 체계적인 정리가 필요하고, 활용되어야 한다. 세계의 각선진국들은 이러한 색의 잠재력을 일찍이 인식하고 그들 자신만의 표준화에 힘을 기울여 왔고 이를 세계의 표준으로 만들려는 노력을 하고 있는 것이다. 정보화, 글로벌화 등의 표현들이 말해주듯 오늘날의 다차원화 된 사회에서 컬러가 차지하는 배색이 중요하다. 따라서 이와 같은 색채조화의 이론적 연구들이 활발히 이루어지길 바란다. The color related departments were given a new degree of importance in recent design, areas of art, and the various areas of industry, which derived from the fact the color contributess to additional assessment of a product, as well as the altered societal influence that places the significance in colors, and the diversity in consumer`s life pattern is shown in the syndrom of the pursuit of the consumers in quality and cultural values. Hence, color cannot be considered as simple `color` anymore. Whereas, color should no longer be defined as a decorative method without reflecting the point of view of the users, but organized scholar and technical order should be given and applied. Number of the world`s advanced countries recognized this pitential of colors in early stages, placed an enormous amount effort on their own means of standardization, and now showing the effort to make this the standardization throughout the world. Such expressions as information and globalization tells people that the rate of magnitude the color occupies will have to increase in current multi-dimensioned society, and as the tendency exists, the importance of pro-environmental color coordination increases directly. Therefore, one hopes for such theoretical research of color coordination, as this one, will be accomplished vigorously.

전립선 암종의 신생혈관 형성과 세포 증식능 및 전립선특이항원 발현정도가 종양전이 및 예후에 미치는 영향

유탁근,이춘용,장세진,박문향 한양대학교 의과대학 1999 한양의대 학술지 Vol.19 No.1

Prostate adenocarcinoma is a significant cause of morbidity and mortality in old men. Recently, with increased screening, there has been much interest in early detection and proper management of this cancer. The best predictors of prognosis in prostate cancer are the stage of disease and histologic differentiation of the cancer. But, preoperative prediction of pathologic stage in prostate cancer is currently limited and histologic differentiation may be somewhat subjective. Therefore, more accurate predictors of biological progression are needed. A number of markers including DNA ploidy, prostate specific antigen(PSA) level, oncogenes, tumor suppressor genes and expression of proteins related to proliferation have been suggested to aid the stage and histologic differentiation in predicting the malignant potential of prostate cancers. The authors designed this study to determine the prediction efficacies of neovascularity, proliferating cell nuclear antigen(PCNA) labeling index and intensity of PSA reaction using immunohistochemical staining, To evaluated above mentioned 3 markers, immunohistochemical stains in 48 cases of prostate cancers and 5 cases of benign prostatic hyperplasia(BPH) were performed and analysed. Microvessels were identified by immunostaining of endothelial cells for factor Ⅷ-related antigen. PCNA labeling indices were obtained in 200X field by counting more than 1,000 cells. The intensity of PSA staining was graded as 0, 1, 2, 3, based on its relationship to the control, and used as scores. The most outstanding staining was considered as 3. The results were as follows: 1. The mean microvessel count(MVC) in BPH group was 34.2±5.9 per 200X field and that of prostate cancer group was 63.5±38.6(p〈0.05). The mean MVC of Gleason grade I prostate cancer was 32.2(16-40). The MVCs were 38.3(23-58), 58.8(23-92), 78.1(18-182) and 86.8(22-180), from grade Ⅱ to V respectively. According to stage, the mean MVCs were 40.8, 48.5, 55.0 and 89.0 from A to D. Between the 2 groups with well differentiated(grade I-Ⅲ) and poorly differentiated(grade Ⅳ-Ⅴ) prostate cancer, there was significant difference in MVC(p〈0.05). And between localized and metastatic group, there was also significant difference. The mean survival of high MVC(MVC≥60) group was 57.4±15.9 months and that of low MVC group was 74.0±11.2 months. But the difference was not statistically significant. 2. The mean PCNA labeling indices were 14.6±8.0% in BPH group and 32.3±15.4% in prostate cancer group. According to Gleason grade, the mean PCNA labeling indices showed the distribution of 33.4(11-55)%, 30.8(19-41)%, 26.3(8-74)%, 38.0(22-55)% and 36.6(12-72)% from I to V respectively. According to stage, the mean value of stage A was 23.1(11-55)%. The mean values were 27.4(8-41)%, 30.4(21-51%) and 36.2(8-74)% in stage B, C and D. Between localized and metastatic group, the difference of PCNA labeling index was not statistically significant. The mean survival of high labeling index(≥30%) group was 66.0±12.2 months contrasted with 72.4±14.6 months of low labeling index group(p〉0.05). 3. The intensities of PSA staining were as follows: according to grade, from I to V, they were 2, 20, 2.75, 2.50, 1.73 and 1.20, respectively. In stage A, the mean PSA score was 2.67, and those of other stages were 2.62 in B, 2.60 in C and 1.58 in D. Between the 2 groups with well differentiated and poorly differentiated prostate cancer, there was significant differnce in PSA score(p〈0.05). And between localized and metastatic group, there was also significant difference. The mean survival of high intensity(2, 3) group was 74.1±11.6 months contrasted with 48.9±11.5 months in low intensity group(0, 1). But the difference was not statistically significant. These results suggest that microvessel density in prostate adenocarcinoma may be an another prognostic factor supporting clinical stage and histologic differentiation. In addition, the intensity of PSA immunostaining can be used as a predictor of malignant potential. But relatively negative results were obtained for PCNA labeling index from this study. To further define MVC and PSA staining intensity as predictors of prostate cancer, more enthusiastic and well designed studies are needed.

Three Cases of Congenital Smooth Muscle Hamartomas

( Jung Keun Kim ),( Tae Ho Park ),( Jae Hak Yoo ),( Kea Jeung Kim ),( Hyang Joon Park ) 대한피부과학회 2007 Annals of Dermatology Vol.19 No.1

Congenital smooth muscle hamartomas (CSMHs) usually appear at birth as skin-colored or slightly hyperpigmented patches or plaques on the trunk or extremities and are often covered by and increased amount of vellus hair. Histopathologically, it represents a proliferation of smooth muscle bundles within the dermis1,2. We herein report on three cases of localized CSMHs; Case 1 was a 2-month-old boy who presented with a skin-colored, 6×5cm-sized plaque with folds, hypertrichosis and pseudo-Darier`s sign on the face, an unusual site. But there was no hyperpigmentation. Case 2 and 3 were both 1-month-old boys who presented with typical hyperpigmented, hairy plaques on the lateral aspect of the left thigh. (Ann Dermatol (Seoul) 19(1) 38~42, 2007)

해석 방법에 따른 창호-벽체 접합부의 결로 방지 성능 비교

유동철(Yoo, Dong-Chul),장향인(Jang, Hyang-In),박창영(Park, Chang-Young),이정근(Lee, Jeong-Keun),최창호(Choi, Chang-Ho) 대한건축학회 2016 대한건축학회논문집 Vol.32 No.10

The purpose of this paper is to compare calculation results of performances of condensation resistance of joints of windows and walls according to analysis standards, simulation programs, and modeling methods and also analyze the causes. Domestic and relevant foreign criteria were reviewed, and Heat transfer simulation was conducted targeting double and triple glass windows. Also, an improved modeling plan was proposed comparing performance of condensation Resistance depending on the modeling approach. The analysis results, from different calculation methods of effective thermal conductivity of cavity spaces showed significant differences in accordance with the analysis standards. It appeared that automatic calculation of effective thermal conductivity by ISO 15099 was impossible using Physibel Bisco. Therefore, an improved and simplified modeling method using respective heat transmission coefficients for window panes and frames was proposed. It was confirmed that compared to the simple modeling, the improved modeling method decreased errors of surface temperature on joints of windows and walls by up to 10% and compared to the detail modeling, all modeling cases were within 10% or less.

Forming process of unipolar resistance switching in Ta2O5-x thin films

Shin Buhm Lee,Hyang Keun Yoo,Bo Soo Kang 한국물리학회 2013 Current Applied Physics Vol.13 No.7

We investigated the film-thickness and ambient oxygen-pressure dependence of the electric field, EF,required to initiate unipolar resistance switching (URS) in Ta2O5-x thin films. We measured the dependence of EF by applying a triangular-waveform voltage signal to the film over a wide sweep-rate range (v = 20 mV s-1 to 5 MV s-1). Our results showed that the URS-EF was not influenced by the Ta2O5-x film thickness nor ambient oxygen-pressure. This suggested that the URS-forming process in Ta2O5x thin films should be governed by thermally assisted dielectric breakdown in our measurement range.

Human bone marrow-derived mesenchymal stem cell gene expression patterns vary with culture conditions

Lee, Myoung Woo,Kim, Dae Seong,Yoo, Keon Hee,Kim, Hye Ryung,Jang, In Keun,Lee, Ji Hyang,Kim, So Yeon,Son, Meong Hi,Lee, Soo Hyun,Jung, Hye Lim,Sung, Ki Woong,Koo, Hong Hoe Korean Society of Hematology; Korean Society of Bl 2013 Blood Research Vol.48 No.2

<P><B>Background</B></P><P>Because of the heterogeneity of human mesenchymal stem cells (MSCs), methods for cell expansion in culture and the effects on gene expression are critical factors that need to be standardized for preparing MSCs. We investigated gene expression patterns of MSCs with different seeding densities and culture times.</P><P><B>Methods</B></P><P>Bone marrow-derived MSCs were plated at densities from 200 cells/cm<SUP>2</SUP> to 5,000 cells/cm<SUP>2</SUP>, and the gene expression patterns were evaluated over time using a reverse-transcription polymerase chain reaction assay.</P><P><B>Results</B></P><P>The mRNA levels of factors that play a critical role in cell migration and tissue regeneration, such as podocalyxin-like protein (PODXL), α4-integrin, α6-integrin, and leukemia inhibitory factor (LIF), were higher in MSCs plated at 200 cells/cm<SUP>2</SUP> than in MSCs plated at 5,000 cells/cm<SUP>2</SUP>. The mRNA levels of these factors gradually increased for 10 days and then decreased by day 15 in culture. MSCs seeded at 200 cells/cm<SUP>2</SUP> that were cultured for 10 days expressed high levels of Oct-4 and Nanog. Indoleamine 2,3-dioxygenase, cyclooxygenase-1, and hepatocyte growth factor expression were upregulated in the presence of the proinflammatory cytokine interferon-γ in these cells.</P><P><B>Conclusion</B></P><P>We found differences in the gene expression patterns of MSCs under different culture conditions. MSCs from 10-day cultures seeded at a low density were efficiently expanded, expressed PODXL, α6-integrin, α4-integrin, and LIF, and maintained properties like stemness and immunomodulation. Therefore, <I>ex vivo</I> expansion of MSCs maintained for an adequate culture time after plating at low cell density can provide an effective regenerative medicinal strategy for cell therapies using MSCs.</P>

Methods for distinguishing Mott transitions from Anderson transitions

Wang, Yue,Kang, Kyung Mun,Kim, Minjae,Yoo, Hyang Keun,Park, Hyung Ho Inderscience Enterprises Ltd. 2018 International Journal of Nanotechnology Vol.15 No.6

흰쥐에서 신델라 겔 (송아지 제단백혈액추출물 : 황산미크로노마이신=20:1 복합제제)의 30일간 반복투여 경피독성시험

남석우(Suk Woo Nam),성대석(Dae Suk Sung),유세근(Se Keun Yoo),장만식(Man Sik Chang),최완수(Wahn Soo Choi),정영국(Young Kuk Chung),김규봉(Kyu Bong Kim),한정환(Jeung Whan Han),홍성렬(Sung Youl Hong),이향우(Hyang Woo Lee) 대한약학회 1997 약학회지 Vol.41 No.2

This study was conducted to investigate the subacute transdermal toxicity of Syndella gel, a new topical drug containing deproteinized dialysate of calf''s blood and micronomicin sulfate in Sprague-Dawley rats. Three doses (1.97, 3.94, 7.88 g/kg) of Syndella gel was daily treated transdermally to male and female rats for 30 days. No death was occurred in either control or treated rats. No significant toxic clinical signs and body weight change were not observed at any doses in the male or female rats treated. There were no significant alterations in hematologic and biochemical parameters in both sexes, however slight increase of potassium concentration was observed in 3.94g/kg and 7.88 g/kg female groups. No significant necrotic changes were not observed in examined organs. This study showed that up to 7.88g/kg Syndella gel did not induce subacute transdermal toxicity.