Enhanced performance of organic electroluminescence diodes with a 2-TNATA:C60 hole injection layer

Kang, H.S.,Park, K.N.,Cho, Y.R.,Park, D.W.,Choe, Y. Korean Society of Industrial and Engineering Chemi 2009 Journal of industrial and engineering chemistry Vol.15 No.5

C60-doped 2-TNATA (4,4',4''-tris(2-naphthylphenylamino)triphenylamine) as a hole injection material and NPD (4,4'bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl) as a hole transport material are used to fabricate OLEDs via vacuum deposition process in this study. C60-doped 2-TNATA film was treated by means of thermal annealing and in situ electromagnetic field. According to AFM, SEM, XRD, and Raman spectra results, by both thermal annealing and in situ electromagnetic field treatments, the smoothened surface and the closely packed morphology of 2-TNATA:C60 film was obtained without any evidences of crystalline nature after those treatments. The treatments eventually lead to enhancing the current density and efficiency of the multi-layered ITO/2-TNATA:C60 (5% doped) (70nm)/NPD (30nm)/Alq<SUB>3</SUB> (50nm)/LiF (1nm)/Al (100nm) devices by facilitating hole injection/transport in the multi-layered organic devices. Consequently, thermal annealing treatment for the 2-TNATA:C60 film is preferred rather than in situ electromagnetic field treatment so as to improve the overall performance of the organic light-emitting diodes in this study.

KDM3B Is the H3K9 Demethylase Involved in Transcriptional Activation of imo2 in Leukemia

Kim, J.-Y.,Kim, K.-B.,Eom, G.H.,Choe, N.,Kee, H.J.,Son, H.-J.,Oh, S.-T.,Kim, D.-W.,Pak, J.H.,Baek, H.J. AMERICAN SOCIETY FOR MICROBIOLOGY 2012 Molecular and cellular biology Vol.32 No.14

絹絲 LOUSINESS에 對한 硏究 (Ⅱ)

崔炳熙,金洛禎,朴光義,南重熙 서울대학교 1964 서울대학교 論文集 Vol.15 No.-

This treatise was carried out to study the heredity phenomenon of silk lousiness and the interaction of genes related with silk lousiness. It was also studied how to improve the silk lousiness of general raw silk by refining process because the mutational or selective process was found as unsatisfactory method. The conclusion reached were as follows. A. Conclusions related with genetic problem. 1. The decreased effects of the lousiness were 11% in the F₁hybrids. 2. Lousiness was considered to inherit as the incomplete dominance. 3. The effects of the lousiness gene were additive, and the lousiness of raw silk might be influenced by more than two genes. 4. The quantitative characters of cocoons were not genetically correlated with the occurance of lousiness. 5. Lousiness could not be said to occur more in the heavy-cocoon strains. 6. The microscopic lousiness test of this paper showed the same result of the international exforiation test. B. Conclusions related with lousiness improvement. 1. Raw silk was able to refine by the employment of 0.2% cationic softener solution for 30 minutes at 95℃ refining bath without the occurance of lousiness. 2. Anionic chemical softener was not available for silk refining process. 3. The above cationic softener refining process did not cause any physical defect for the silk fiber. 4. Soap refining process caused silk lousiness easily.

絹絲 LOUSINESS 에 對한 硏究(Ⅰ)

崔炳熙,金洛禎,朴光義,南重熙 서울대학교 1963 서울대학교 論文集 Vol.14 No.-

This treatise is to set up a fundermental condition of checking silk lousiness and to set up a new improving method of cocoon bave lousiness after suer refining treatment. It is also studied whether silk lousiness can be eliminated through the observation of the silk gland or the lousiness can be able to improve through such a study. The conclusions obtained in this paper are as follows. 1. Silk lousiness is able to be observed most properly when the light direction and the fiber direction is paralleled in plan view of the silk cloth and the greater the angle between them is, the less the lousiness is observed. When, however, the angle is greater than some specific angle (30˚), no more lousiness is observed. This specific angle was named by the author as Lousiness Horizontal Critical Angle. 2. Silk lousiness can be observed when the angle of light incidense against the silk cloth is six degree, while the large the angle is, the less the lousiness is observed. When, however, the angle is greater than some specific angle(45˚), the lousiness disappears. Such a specific angle was named by the author as Lousiness vertical Critical Angles. 3. The best textile composition to decrease lousiness defect is plan weave, while twill and satin weave show more lousiness with same silk fiber. 4. Lousiness was classified as Lousiness A, B and C of which A was the general lousiness, B was the group type, and C was the glucose type one, and the standard photographs for the lousiness grading of these types were prepared. 5. The proper soap refining hours of silk for lousiness test was determined as eight hours. 6. The greater the difference of fiber diameter between the cocoon single bave and the splitend was, the more lousiness was composed. The normal splitends were measured as 1/4-1/5 of the main fiber. 7. The lousiness was found at the cocoon shape ends more than other parts, and found at the middle cocoon layer than other layer which was imagined to be as a result of poor uniform bave spinning of silk worm. 8. Male cocoon had more lousiness than the female cocoon. 9. It was found that there was a great possibility to have the splitends through the observation of the anatomical silk gland, and the author reached as conclusion that the lousiness can be improved some only be elimination of abnormal silk gland from the breeding aspects. 10. The cocoon bave of the offspring after super refining lousiness test and selection showed more improved lousiness defect than that of the parent.

Effects of phosphorus on the δ-Ni₃Nb phase precipitation and the stress rupture properties in alloy 718

Sun,W.R.,Lee,J.H.,Guo,S.R.,Yoo,Y.S.,Choe,S.J.,Park,N.K.,Hu,Z.Q. 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

The effects of phosphorus on the phase transformation and stress rupture properties of alloy 718 were investigated. The nucleation of δ- phase, which does not contain phosphorus, was suppressed by the enrichment of phosphorus at grain boundaries. A low level of phosphorus resulted in the formation of faults-containing film-like δ- phase along the grain boundaries, while a higher level of phosphorus favored the long lath-like δ- phase precipitation. Phosphorus greatly prolonged the stress rupture life of the alloy in the range of 0.0008-0.013 wt.% while it reduced the stress rupture life in the range of 0.013-0.049 wt.% The effect of phosphorus in the stress rupture properties was closely related to its interaction with oxygen. Phosphorus atoms, in the range of 0.0008-0.013 wt.%, enhanced the resistance to oxygen intrusion along the grain boundaries, protected the grain boundaries from decohesion by oxygen atoms and oxidation, and subsequently prolonged the rupture life of the alloy. The protection effect of p is clearly demonstrated by the phenomenon that the crack initiation site was shifted from the surface to the center in the stress-ruptured samples with increasing addition of P. Over 0.013 wt.%, the protection effect of phosphorus is excessive and phosphorus began to display its inherent effect of damaging the grain boundary strength ; the stress rupture life of the alloy was reduced accordingly. Maximum stress rupture life was thus obtained at ∼0.013 wt.% P ⓒ 1998 Elsevier Science S.A. All rights reserved.

IR CAT Scan 개발을 위한 기하학적 역 열전도 문제의 경계요소 해법

박천태,김태한,최순호,최창용,한기남 韓國非破壞檢査學會 1995 한국비파괴검사학회지 Vol.15 No.1

IR CAT Scan 개발을 위한 기하학적 역 열전도 문제의 해를 경계요소법 및 정규화 과정을 사용하여 구하였다. 이 문제에서는 잉여기술된 온도조건이 적외선 스캐닝에 의해 표면에 주어지며, 이 조건은 다른 조건과 함께 미지경계의 위치를 계산하는데 사용되었다. 문제의 해를 구하기 위해 보조문제가 도입되었고, 이 보조문제의 영역에 대한 가상적인 내부경계를 정의함으로써 공동(cavity)이 영역 내부에 위치하게 되며, 포텐셜 문제의 해를 구하여 그 위치를 결정하였다. 이 문제의 해를 구하기 위해 경계요소법이 정규화 과정과 함께 사용되었으며, 수치해석을 통하여 역 해법에 대한 정규화 효과를 분석하였다. A geometrical inverse heat conduction problem is solved for the development of Infrared Computerized-Axial-Tomography (IR CAT) Scan by using a boundary element method in conjunction with regularization procedure. In this problem, an overspecified temperature condition by infrared scanning is provided on the surface, and is used together with other conditions to solve the position of an unknown boundary (cavity). An auxiliary problem is introduced in the solution of this problem. By defining a hypothetical inner boundary for the auxiliary problem domain, the cavity is located interior to the domain and its position is determined by solving a potential problem. Boundary element method with regularization procedure is used to solve this problem, and the effects of regularization on the inverse solution method are investigated by means of numerical analysis.

한국인 CCR5 유전자에서의 돌연변이 빈도

오명돈,김성순,김은영,이선희,김남정,박근용,김유석,김소마,김태규,최강원,이주실 국립보건연구원 2000 국립보건원보 Vol.37 No.-

Prevalence of yeast‐like fungi and evaluation of several virulence factors from feral pigeons in Seoul, Korea

Jang, Y.H.,Lee, S.J.,Lee, J.H.,Chae, H.S.,Kim, S.H.,Choe, N.H. Blackwell Publishing Ltd 2011 Letters in applied microbiology Vol.52 No.4

<P><B>Abstract</B></P><P><B>Aims: </B> Studies of pigeon‐borne yeasts have tended to focus on species, such as <I>Cryptococcus neoformans</I> and <I>Candida albicans</I>, with scant attention to feral pigeons in Korea. We studied the prevalence of yeasts from faecal samples of feral pigeons obtained in various public places in Seoul, Korea, and assessed their potential capacity as human pathogens.</P><P><B>Methods and Results: </B> Three hundred and six pigeon faeces samples were collected at city squares and parks in 21 localities in Seoul and Seoul Grand Park and analysed for yeast with conventional methods. Of the 306 samples, 126 (41·2%) were positive for yeast. Seventeen species of yeast were identified. The most frequent species were <I>Candida glabrata</I> (34·1%), <I>Candida famata</I> (12·7%), <I>Cryptococcus albidus</I> (14·3%) and <I>Cryptococcus laurentii</I> (7·9%). The yeast isolates were tested for virulence. Of the 116 isolates (ten isolates missing), 70·7% (<I>n</I> = 82) grew at 37°C. All the <I>Cryptococcus</I> spp. isolates possessed a capsule, 16·4% (<I>n</I> = 19) produced melanin, and 33·6% (<I>n</I> = 39) produced proteinase. Two <I>Ca.?glabrata</I>, a <I>Ca.?famata</I> and <I>Ca.?albicans</I> as well as three <I>C.?neoformans</I>, a <I>C.?laurentii</I> and <I>Ca.?albicans</I> isolates had three virulence factors. Accordingly, 29·3% (<I>n</I> = 34) isolates possessed more than two virulence factors except capsule formation.</P><P><B>Conclusions: </B> These results of this study indicate that feral pigeons harbour a variety of yeasts and are a reservoir of human pathogenic fungi.</P><P><B>Significance and Impact of the Study: </B> This study is the first time about the microflora (fungi) presents in faecal samples collected from a variety of public areas throughout Seoul, Korea.</P>

Decreased number and function of endothelial progenitor cells in patients with migraine

Lee, S. -T.,Chu, K.,Jung, K. -H.,Kim, D. -H.,Kim, E. -H.,Choe, V. N.,Kim, J. -H.,Im, W. -S.,Kang, L.,Park, J. -E.,Park, H. -J.,Park, H. -K.,Song, E. -C.,Lee, S. K.,Kim, M.,Roh, J. -K. Ovid Technologies (Wolters Kluwer) - American Acad 2008 Clinical Neurophysiology Vol.70 No.17

<P>OBJECTIVE: Migraine carries an increased risk for cardiovascular and cerebrovascular diseases that cannot be explained by traditional cardiovascular risk factors. The circulating endothelial progenitor cell (EPC) number is a surrogate biologic marker of vascular function, and diminished EPC counts are associated with higher cardiovascular risk. We investigated whether abnormalities in EPC levels and functions are present in migraine patients. METHODS: Consecutive headache patients (n =166) were enrolled, including those with tension type headache (TTH; n = 74), migraine without aura (MO; n = 67), and migraine with aura (MA; n = 25). EPC colony-forming units in peripheral blood samples and migratory capacity to chemoattractants (stromal cell-derived factor 1 and vascular endothelial growth factor) and cellular senescence levels were assayed in risk factor-matched subjects (n = 6 per group). RESULTS: The TTH group had more cardiovascular risk factors, more headache days, and higher Framingham risk scores than the other two groups. Mean numbers of EPC colony-forming units were 47.8 +/- 24.3 in TTH, 20.4 +/-22.2 in MO, and 8.6 +/- 10.1 in MA patients (p < 0.001 in TTH vs MO; p = 0.001 in MO vs MA). EPC colony counts of normal subjects (n = 37) were not significantly different from those with TTH. Multiple linear regression models identified only MO, MA, and the presence of migraine (MO + MA) as significant predictors of EPC levels. In addition, EPCs from migraine patients (MO and MA) showed reduced migratory capacity and increased cellular senescence compared with EPCs from TTH or normal subjects. CONCLUSION: Circulating endothelial progenitor cell (EPC) numbers and functions are reduced in migraine patients, suggesting that EPCs can be an underlying link between migraine and cardiovascular risk.</P>

The microRNA miR-124 inhibits vascular smooth muscle cell proliferation by targeting S100 calcium-binding protein A4 (S100A4)

Choe, N.,Kwon, D. H.,Shin, S.,Kim, Y. S.,Kim, Y. K.,Kim, J.,Ahn, Y.,Eom, G. H.,Kook, H. Elsevier Science B.V., Amsterdam. 2017 FEBS letters Vol.591 No.7

<P>S100 calcium-binding protein A4 (S100A4) induces proliferation and migration of vascular smooth muscle cells (VSMCs). We aimed to find the microRNA regulating S100A4 expression. S100A4 transcripts are abruptly increased in the acute phase of carotid arterial injury 1 day later (at day 1) but gradually decreases at days 7 and 14. Bioinformatics analysis reveals that miR-124 targets S100A4. VSMC survival is attenuated by miR-124 mimic but increased by miR-124 inhibitor. miR-124 decreases immediately after carotid arterial injury but dramatically increases at days 7 and 14. miR-124 inhibitor-induced cell proliferation is blocked by S100A4 siRNA, whereas miR-124-induced cell death is recovered by S100A4. Our findings suggest that miR-124 is a novel regulator of VSMC proliferation and may play a role in the development of neointimal proliferation.</P>