• Title/Summary/Keyword: $\alpha$-CD

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The Synthetic Study of Environmental Contamination at the Seokdae Municipal Waste Landfill in Pusan (부산 석대 생활폐기물 매립장의 환경오염에 대한 종합적 연구)

  • 김병우;정상용;이민희;이병헌
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.98-103
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    • 2001
  • In order to understand the characteristics of leachate at the Seokdae municipal waste landfill in the Pusan city, the correlation between leachate pollution loading and volume of gas production. concentration of gas and subsidence of ground, the characteristical methos, geochemical analyses and laboratory column tests using samples of gases, leachate and surface soil of Seokdae waste landfill area. Through the analysis of water balance, leachate flow rate and pollution loading were estimated. Geistatistical analysis of four gas components ( $O_2$, C $H_4$, $H_2$S and CO) shows the possibility of ground subsidence around the group of a site with high concentration of gas. From geochemical analyses of leachate, EC and Total-Alkalinity of ground subsidence around the group of a site with high concentration of gas. From geochemical analysis of leachate, Ec and Total-Alkalinity were increased, and Cl, Cr, Mn, Cu, Zn, Cd and Pb were decreassed comparing to the part, and the type of water quality was Na-HC $O_3$ in trilinear diagram. It shows that biodecomposition of municipal wastes continues actively. From the analysis of water balance, the total leachate flow rate is about 465.11㎥/day and pure pollution loading of Cl, Mn and Fe are estimated to 223.8kg/day, 0.2kg/day, 0.3kg/day, respectively. The laboratory column test of residual soil and landfill soil shows 0.206cm and 0.019cm for linear velocity(equation omitted), 0.234 $\textrm{cm}^2$/min and 0.018$\textrm{cm}^2$/min for diffusion coefficient ( $D_{ι}$), and 1.136cm and 0.095cm longitudinal dispersion index ($\alpha$$_{ι}$), respective]y. It demonstrates that the delay time of contamination for residual soil is shorter than that of landfill soil.

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A Comparative Study on the Immunizing and Anti-cancer Effect of the Root and the Aerial Part of Peucedanum Japonicum Thunb (갯기름나물의 근(根)과 경엽(莖葉)의 면역 및 항암 활성 비교연구)

  • Cho, Yong-Ho
    • Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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    • v.1 no.1
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    • pp.127-144
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    • 2005
  • This study compared the activity of the aerial part of P. japonicum with its root in order to examine the possibility of the medicinal use of the aerial part, which has not been used as medicine, in substitute for the root that has traditionally been used as medicine. For this purpose, the author measured the proliferation of Human $CD4^-$ T cells, which are related to immunity, the differentiation of HL-60 cells, and the contents of IL-6, IgE and $TNF-{\alpha}$ and compared their anti-cancer effect on Hep3B and A549 cells. The results of this study are as follows: 1. As for Human $CD4^-$ T cells, $1.0\;g/{\ell}$ methanol extract from the aerial part promoted the proliferation of the cells 1.8 times higher while $1.0\;g/{\ell}$ methanol extract from the root did by 1.76 times higher compared to the control group. 2. As for HL-60 cells, methanol extract and water extract from the aerial part showed differentiation 1.14 times higher and 1.12 times higher respectively while methanol extract and water extract from the root did 1.14 times higher and 1.07 times higher compared to tile control group. 3. Cell density was highest on Day 4 of culture in all samples, Methanol extracts from the aerial part and the root showed activities of $7.9{\times}10^3\;cells/m{\ell}$ and $7.5{\times}10^3\;cells/m{\ell}$ respectively, and water extracts from the aerial part and the root did activities of $5.3{\times}10^3\;cells/m{\ell}$ and $6.1{\times}10^3\;cells/m{\ell}$. 4. The secretion of IL-6 was highest on Day 4 of culture. Methanol extracts from the aerial part and the root showed secretions of $6.7{\times}10^{-3}\;pg/cells/m{\ell}$ and $7.2{\times}10^{-3}\;pg/cells/m{\ell}$ respectively, and water extracts from the aerial part and the root did secretions of as high as $7.0{\times}10^{-3}\;pg/cells/m{\ell}$ and $6.0{\times}10^{-3}\;pg/cells/m{\ell}$. 5. As for the production of IgE, water extract from the root effectively inhibited the product at $1,000\;{\mu}g/m{\ell}$, methanol extract from the root at $10\;{\mu}g/m{\ell}$ and $100\;{\mu}g/m{\ell}$, water extract from the aerial at $1,000\;{\mu}g/m{\ell}$, and methanol extract from the aerial part at $1,000\;{\mu}g/m{\ell}$. 6. According to the result of measuring the content of $TNF-{\alpha}$, methanol extracts from the root and the aerial part showed inhibition effect at $10\;{\mu}g/m{\ell}$, $100\;{\mu}g/m{\ell}$ and $1,000\;{\mu}g/m{\ell}$. 7. As for liver cancer cell Hep3B, $1.0\;g/{\ell}$ methanol extracts from the root and the aerial part showed inhibition effects of 78% and 70% respectively, and $1.0\;g/{\ell}$ water extracts from the root and the aerial part did inhibition effects of 56% and 59%. 8. As for lung cancer cell A549, $1.0\;g/{\ell}$ methanol extracts from the root and the aerial part showed inhibition effects of 75% and 70% respectively, and $1.0\;g/{\ell}$ water extracts from the root and the aerial part did inhibition effects of 48% and 45%. The results of this study presented above show that the aerial part of P. japonicum has immunizing and anti-cancer effects as high as its root, which has commonly been used as medicine. There should be more in-depth research on the aerial part of P. japonicum in the future.

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Solution Structure of 21-Residue Peptide (Asp 84-Leu 104), Functional Site derived from $p16^{INK4A}$ ($p16^{INK4A}$ 단백질 활성부위(Asp 84-Leu 104)의 용액상 구조)

  • Lee, Ho-Jin;Ahn, In-Ae;Ro, Seonggu;Choi, Young-Sang;Yoon, Chang No;Lee, Kang-Bong
    • Analytical Science and Technology
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    • v.13 no.4
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    • pp.494-503
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    • 2000
  • A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

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Melanogenesis regulatory constituents from Premna serratifolia wood collected in Myanmar

  • WOO, SO-YEUN
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.21-22
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    • 2019
  • Melanin is a mixture of pigmented biopolymers synthesized by epidermal melanocytes that determine the skin, eye, and hair colors. Melanocytes produce two different kinds of melanin, eumelanin (dark brown/black insoluble pigments found in dark skin and dark hair and pheomelanin (lighter red/yellow). The biological role of melanin is to prevent skin damage by ultraviolet (UV) radiation. However, the overproduction or deficiency of melanin synthesis could lead to serious dermatological problems, which include melasma, melanoderma, lentigo, and vitiligo. Therefore, regulating melanin production is important to prevent the pigmentation disorders. Myanmar has a rich in natural resources. However, the chemical constituents of these natural resources in Myanmar have not been fully investigated. In the effort to search for compounds with anti-melanin deposition activity from Myanmar natural resources, five plants were collected in Myanmar. Extracts of these collected five plants were tested for anti-melanin deposition activity against a mouse melanoma cell line (B16-F10) induced with ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) and 3-isobutyl-1-methylxanthine (IBMX), and their anti-melanin deposition activities were compared with the positive control, arbutin. Among the tested extracts, the CHCl3 extracts of the Premna serratifolia (syn: P. integrifolia) wood showed anti-melanin deposition activities with IC50 values of $81.3{\mu}g/mL$. Hence, this study aims to identify secondary metabolites with anti-melanin deposition activity from P. serratifolia wood of Myanmar. P. serratifolia belongs to the Verbenaceae family and is widely distributed in near western sea coast from South Asia to South East Asia, which include India, Malaysia, Vietnam, Cambodia, and Sri Lanka. People in Tanintharyi region located in the southern part of Myanmar utilize the P. serratifolia, Sperethusa crenulata, Naringi crenulata, and Limonia acidissima as Thanaka, traditional cosmetics in Myanmar. Thanaka is applied in the form of paste onto skins to make it smooth and clear, as well as to prevent wrinkles, skin aging, excessive facial oil, pimples, blackheads, and whiteheads. However, the chemical constituents responsible for their cosmetic properties are yet to be identified. Moreover, the chemical constituents of P. serratifolia was almost uncharacterized. Investigation of the P. serratifolia chemical constituents is thus an attractive endeavor to discover new anti-melanin deposition active compounds. The investigation of the chemical constituents of the active CHCl3 extract of P. serratifolia led to isolation of four new lignoids, premnan A (1), premnan B (2), taungtangyiol C (3), and 7,9-dihydroxydolichanthin B (4), together with premnan C (5) (assumed to be an artifact), one natural newlignoid,(3R,4S)-4-(1,3-benzodioxol-5-ylcarbonyl)-3-[(R)-1-(1,3-benzo dioxol-5-yl)-1-hydroxy methyl]tetrahydro-2-furanone (6), and five known compounds (7-11)1,2). The structures of all isolated compounds were determined on the basis of their spectroscopic data and by comparison with the reported literatures. The absolute configurations of 1-3 and 5 were also determined by optical rotation and circular dichroism (CD) data analyses1). The anti-melanin deposition activities of all the isolated compounds were evaluated against B16-F10 cell line. 7,9-Dihydroxydolichanthin B (4) and ($2{\alpha},3{\alpha}$)-olean-12-en-28-oic acid (11) showed strong anti-melanin deposition activities with IC50 values of 18.4 and $11.2{\mu}M$, respectively, without cytotoxicity2). On the other hand, compounds 1-3, 5, and 7 showed melanogenesis enhancing activities1). To better understand their anti-melanin deposition mechanism, the effects of 4 and 11 on tyrosinase activities were investigated. The assay indicated that compounds 4 and 11 did not inhibit tyrosinase. Furthermore, we also examined the mRNA expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). Compounds 4 and 11 down-regulated the expression of Tyr and Mitf mRNAs, respectively. Although the P. serratifolia wood has been used as traditional cosmetics in Myanmar for centuries, there are no scientific evidences to support its effectiveness as cosmetics. Investigation of the anti-melanin deposition activity of the chemical constituents of P. serratifolia thus provided insight into the effectiveness of the P. serratifolia wood as a cosmetic agent.

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Chemical and Microbiological Hazard Analysis of Floor-Settled Dust in Elementary School Classrooms in Korea (국내 일부 초등학교 바닥먼지 내 화학적 및 생물학적 유해인자의 분석)

  • Kim, Ji-Young;Jung, Se-Young;Kim, Su-Jung;Kim, Jin-Ah;Si, Ji-Yeon;Jo, Yeon-Woo;Zoh, Kyung-Duk;Ko, Gwang-Pyo
    • Journal of Environmental Health Sciences
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    • v.37 no.4
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    • pp.279-288
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    • 2011
  • Objectives: This study investigated the levels and components of floor-settled dust in two elementary schools located at different sites (one near the Shihwa industrial complex and the other in a rural area) in order to evaluate the amounts of trace metal elements (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) and microorganisms. Methods: Over twenty settled-dust samples were collected from the two elementary schools. Trace metal elements were extracted from the dust using hydrochloric acid and nitric acid, and the amounts were measured by ICP-OES. Microbiological analysis was performed by bacterial culturing using R2A medium and denaturing gradient gel electrophoresis (DGGE). Results: The results showed that the amounts of three metal elements (Cr, Pb, and Zn) were significantly different between the schools (${\alpha}$=0.05, p<0.04). In addition, microbial communities in each school were highly correlated with one another. Among the identified microorganisms, a number of potentially opportunistic microorganisms, including antibiotic-resistant bacteria such as Acinetobacter baumannii, were found. Conclusions: This study will provide preliminary data for assessing levels and types of chemical and microbiological agents in elementary schools and for further evaluating human health risks associated with the agents.

A Study of the Photoluminescence of ZnO Thin Films Deposited by Radical Beam Assisted Molecular Beam Epitaxy (라디칼 빔 보조 분자선 증착법 (Radical Beam Assisted Molecular Beam Epitaxy) 법에 의해 성장된 ZnO 박막의 발광 특성에 관한 연구)

  • Suh, Hyo-Won;Byun, Dong-jin;Choi, Won-Kook
    • Korean Journal of Materials Research
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    • v.13 no.6
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    • pp.347-351
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    • 2003
  • II-Ⅵ ZnO compound semiconductor thin films were grown on $\alpha$-Al$_2$O$_3$(0001) single crystal substrate by radical beam assisted molecular beam epitaxy and the optical properties were investigated. Zn(6N) was evaporated using Knudsen cell and O radical was assisted at the partial pressure of 1$\times$10$^{4}$ Torr and radical beam source of 250-450 W RF power. In $\theta$-2$\theta$ x-ray diffraction analysis, ZnO thin film with 500 nm thickness showed only ZnO(0002)and ZnO(0004) peaks is believed to be well grown along c-axis orientation. Photoluminescence (PL) measurement using He-Cd ($\lambda$=325 nm) laser is obtained in the temperature range of 9 K-300 K. At 9 K and 300 K, only near band edge (NBE) is observed and the FWHM's of PL peak of the ZnO deposited at 450 RF power are 45 meV and 145 meV respectively. From no observation of any weak deep level peak even at room temperature PL, the ZnO grains are regarded to contain very low defect density and impurity to cause the deep-level defects. The peak position of free exciton showed slightly red-shift as temperature was increased, and from this result the binding energy of free exciton can be experimentally determined as much as $58\pm$0.5 meV, which is very closed to that of ZnO bulk. By van der Pauw 4-point probe measurement, the grown ZnO is proved to be n-type with the electron concentration($n_{e}$ ) $1.69$\times$10^{18}$$cm^3$, mobility($\mu$) $-12.3\textrm{cm}^2$/Vㆍs, and resistivity($\rho$) 0.30 $\Omega$$\cdot$cm.

Effects of Moxi-tar Herbal Acupuncture of LI11 on inflammatory bowel disease induced by TNBS in mice (TNBS로 유도된 대장염에서 곡지의 구진약침 효과)

  • Song, Moon-Young;Park, Sang-Yeon;Kim, Jae-Hyo;Ahn, Sung-Hun;Kim, Kyoung-Sik;Sohn, In-Chul
    • Korean Journal of Acupuncture
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    • v.25 no.3
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    • pp.147-166
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    • 2008
  • Objectives : Crohn's disease (CD) is characterized by a chronic relapsing inflammation of the bowel in which proinflammatory cytokines play an important perpetuating role. Methods : Mice (preventive animal model of gliotoxin) were treated with 5 % 2,4,6-trinitrobenzenesulfonic acid (TNBS) at day 1 and day 7. To investigate preventive effects of acupuncture with Gujin at $LI_{11}$, acupuncture was carried out at day -1, day 1, day 3. And, to investigate therapeutic effects, acupuncture with Gujin was carried out at day 3, day 5, day 7. For the data analysis, we checked weight and width of colon, diarrhea, edema, survival rate, changes of body weight, and myeloperoxygenase (MPO) activity. For analysing protein expression, we carried out immunohistochemical staining and Western blot and we analyzed mRNA expression by RT-PCR. Results : Colon of TNBS treated mice was erosive and shortening compared with the colon of control mice and induced damages of colon epithelial cell layer and induced infiltration of immune cells in all layer of colon. Acupuncture of gujin at $LI_{11}$ in preventive mode suppressed macorscopic damages such as erosive and shortening of colon by TNBS and damages of intestinal epithelial cells and infiltration of immune cells in the colon. The average weight of 5 cm distal colon was increased in TNBS treated mice (758${\mu}g$) compared with in control mice (112${\mu}g$) and width of distal colon was also increased in TNBS treated mice (4.9mm) compared with in control mice (1.3mm). Acupuncture with Gujin at $LI_{11}$ in preventive and therapeutic mode suppressed increase of colon weight and width by TNBS. TNBS induced edema of colon and diarrhea and Acupunctured with Gujin at $LI_{11}$ in preventive and therapeutic mode ameliorated these symptom by TNBS. In preventive and therapeutic mode, the effects of acupuncture with Gujin at $LI_{11}$ were increasing the motility, suppressing body weight decreasing, suppressing MPO activity, reducing expressing of TNF-${\alpha}$, IL-1b, and ICAM-1 in colon compared with that by TNBS Conclusions : This study demonstrates that acupuncture with Gujin at $LI_{11}$ represents a potential therapeutic method of Crohn's disease.

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Transfection of Mesenchymal Stem Cells with the FGF-2 Gene Improves Their Survival Under Hypoxic Conditions

  • Song, Heesang;Kwon, Kihwan;Lim, Soyeon;Kang, Seok-Min;Ko, Young-Guk;Xu, ZhengZhe;Chung, Ji Hyung;Kim, Byung-Soo;Lee, Hakbae;Joung, Boyoung;Park, Sungha;Choi, Donghoon;Jang, Yangsoo;Chung, Nam-Sik;Yoo, Kyung-Jong;Hwang, Ki-Chul
    • Molecules and Cells
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    • v.19 no.3
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    • pp.402-407
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    • 2005
  • Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury, but this approach is limited by their poor viability after transplantation. To reduce cell loss after transplantation, we introduced the fibroblast growth factor-2 (FGF-2) gene ex vivo before transplantation. The isolated MSCs produced colonies with a fibroblast-like morphology in 2 weeks; over 95% expressed CD71, and 28% expressed the cardiomyocyte-specific transcription factor, Nkx2.5, as well as ${\alpha}$-skeletal actin, Nkx2.5, and GATA4. In hypoxic culture, the FGF-2-transfected MSCs (FGF-2-MSCs) secreted increased levels of FGF-2 and displayed a threefold increase in viability, as well as increased expression of the anti-apoptotic gene, Bcl2, and reduced DNA laddering. They had functional adrenergic receptors, like cardiomyocytes, and exposure to norepinephrine led to phosphorylation of ERK1/2. Viable cells persisted 4 weeks after implantation of $5.0{\times}10^5$ FGF-2-MSCs into infarcted myocardia. Expression of cardiac troponin T (CTn T) and a voltage-gated $Ca^{2+}$ channel (CaV2.1) increased, and new blood vessels formed. These data suggest that genetic modification of MSCs before transplantation could be useful for treating myocardial infarction and end-stage cardiac failure.

Anti-nociceptive and Anti-inflammatory Effects of Gami-cheongyulsaseub-tang in Arthritic Model (관절염 모델에서 가미청열사습탕(加味淸熱瀉濕湯)의 진통 및 소염 효과에 관한 연구)

  • Kim, Il-Hyun;Lee, Ha-Il;Lee, Se-Won;Kwon, Young-Mi;Song, Yung-Sun
    • Journal of Korean Medicine Rehabilitation
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    • v.25 no.1
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    • pp.27-44
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    • 2015
  • Objectives This study was carried out to find the effects of Gami-cheongyulsaseub-tang (hereinafter referred to GCST) on the inhibition of zymosan-induced pain in rats and collagen II-induced arthritis (CIA) in DBA/1J mouse. Methods As an acute inflammatory pain model, peripheral inflammation was induced by intraplantar injection of zymosan into the right hind paw in rats and then the hyperalgesia and pain regulating factors in spinal cord were analyzed. As a chronic inflammation model, the mixture of collagen II and complete Freund's adjuvant was treated into mice to establish rheumatoid arthritis and then body weight, thickness of hind paw, pathological change of spleen, immunological rheumatoid factor (IgG1, IgG2a, IgG2b, IgM and anti-collagen II), pro-inflammatory cytokines, and bone injury were analyzed. Results In the acute inflammatory pain model, GCST significantly inhibited the thermal and mechanical hyperalgesia and the pain regulating factors, including Fos, CD11b, PKA and PKC, in the spinal cord with a dose-dependent manner. In the chronic rheumatoid arthritis model, GCST administration decreased arthritic index and paw edema as compared with CIA control group. In particular, GCST reduced significantly the serum levels of total IgG2a, IgG2b, IgM, and specific anti-collagen II, but not total IgG1. GCST also resulted in the attenuation of bone injury and spleen enlargement/adhesion in CIA mice. Moreover, the secretion of pro-inflammatory cytokines TNF-${\alpha}$ and IL-$1{\beta}$ in CIA mice was significantly reduced by GCST in a dose-dependent manner. Conclusions Comparison of the results in this study showed that GCST had anti-nociceptive and immunomodulatory effects. These data imply that GCST can be used as an effective drug for not only rheumatoid arthritic pain but also other auto-immune diseases.

자장 강화된 유도결합형 플라즈마를 이용한 TFT-LCD용 Al-Nd 박막의 식각 특성 개선에 관한 연구

  • 한혜리;이영준;오경희;홍문표;염근영
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.195-195
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    • 2000
  • TFT-LCD의 제조공정은 박막층의 식각 공정에 대해 기존의 습식 공정을 대치하는 건식식각이 선호되고 있다. 건식 식각 공정은 반도체 공저에 응용되면서 소자의 최소 선폰(CD)이 감소함에 따라 유도결합셩 프라즈마를 비롯한 고밀도 플라즈마 이용한 플라즈마 장비 사용이 증가하는 추세이다. 여기에 평판디스플레이의 공정을 위해서는 대면적과 사각형 기판에 대한 균일도를 보장할 수 있는 고밀도의 균일한 플라즈마 유지가 중요하다. 본 실험에서는 자장강화된 유도결합형 플라즈마의 플라즈마 밀도 및 균일도를 살펴보고 TFT-LCD에 gate 전극으로 사용되는 Al-Nd 박막의 식각을 통하여 식각균일도와 식각속도 및 식각 선택도 등의 건식 식각 특성을 보고자 한다. 영구자석 및 전자석의 설치는 사각형의 유도결합형 플라즈마는 소형 영구자석을 배열하여 부착하였으며, 외부에는 chamber와 같이 사각형태의 전자석을 500mm$\times$500mm의 크기를 갖는 z축 방향의 Helmholtz형으로 제작하였다. 더. 영구자석 배열에 대해서는 자석간의 거리와 세기 변화를 조합하여 magnetic cusping의 변화를 주었으며 전자석의 세기는 전류값을 기준으로 변화시켜 보았다. 실험을 통하여 플라즈마 균일도를 5% 이하로 개선하고 이러한 균일도를 유지하며 플라즈마 밀도를 높일 수 있는 조건을 찾을 수 있었다. 이러한 적합화된 조건에서 저장강화된 유도결합형 프라즈마를 Al-Nd 박막 식각에 응용한 결과, Al-Nd의 식각속도 및 식각 선택도는 유도결합형 프라즈마에 비해 크게 증가하였으며, 식각균일도가 개선되는 것을 관찰하였다. 또한 electrostatic probe(Hiden, Analytical)를 이용하여 Al-Nd 식각에 사용된 반응성 식각가스에 대한 저장강화된 유도결합형 플라즈마의 특성 분석을 수행하였다.c recoil detection, Rutherford backscattering spectroscopy, X-ray diffraction, secondary electron microscopy, atomic force microscoy, $\alpha$-step, Raman scattering spectroscopu, Fourier transform infrared spectroscopy 및 micro hardness tester를 이용하여 기판 bias 전압이 DLC 박막의 특성에 미치는 영향을 조사하였다. 분석결과 본 연구에서 제작된 DLC 박막은 탄소와 수소만으로 구성되어 있으며, 비정질 상태임을 알 수 있었다. 기판 bias 전압의 증가에 따라 박막의 두께가 감소됨을 알 수 있었고, -150V에서는 박막이 거의 만들어지지 않았으며, -200V에서는 기판 표면이 식각되었다. 이것은 기판 bias 전압과 ECR 플라즈마에 의한 이온충돌 효과 때문으로 판단되며, 150V 이하에서는 증착되는 양보다 re-sputtering 되는 양이 더 많을 것으로 생각된다. 기판 bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 (dehydrogenation) 현상을 확인할 수 있었으며, 이것은 C-H 결합에너지가 C-C 결합이나 C=C 결합보다 약하여 수소 원자가 비교적 해리가 잘되므로 이러한 현상이 일어난다고 판단된다. 결합이 끊어진 탄소 원자들은 다른 탄소원자들과 결합하여 3차원적 cross-link를 형성시켜 나가면서 내부 압축응력을 증가시키는 것으로 알려져 있으며, hardness 시험 결과로 이것을 확인할 수 있었다. 그리고 표면거칠기는 기판 bias 전압을 증가시킬수록 더 smooth 해짐을 확인하였다.인하였다.을 알 수 있

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