• Title/Summary/Keyword: Model compound

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Thermal Degradation Characteristics of Carbon Tetrachloride in Excess Hydrogen Atmosphere (과잉수소 반응조건하에서 사염화탄소의 고온 분해반응 특성 연구)

  • Won, Yang-Soo;Jun, Kwan-Soo;Choi, Seong-Pil
    • Journal of Environmental Science International
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    • v.5 no.5
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    • pp.569-577
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    • 1996
  • pure compound chloromethanes; methyl chloride, methylene chloride, chloroform and The carbon tetrachloride were used as a model of chlorocarbon system with Cl/H ratio to investigate thermal stability and hydrodechlorination process of carbon tetrachloride under excess hydrogen atmosphere. The parent thermal stability on basis of temperature required for 99% destruction at 1 second no was evaluated as $875^{\circ}C$ for $CH_3Cl$, $780^{\circ}C$ for $CH_2Cl_2$, $675^{\circ}C$ for $CHCl_3$ and $635^{\circ}C$ for $CCl_4$. Chloroform was thermally less stable than $CCl_4$ at fairly low temperatures $(<570^{\circ}C).$ The lion of $CCl_4$ became more sensitive to increasing temperature, and $CCl_4$ was degraded CHCl3 at above $570^{\circ}C.$ The number and quantity of chlorinated products decreases with increasing temperature for the Product distribution of $CCl_4$ decomposition reaction system. Formation of non-chlorinated hydrocarbons such as $CH_4$, $C_2H_4$ and C_2H_6$ increased as the temperature rise and particularly small amount of methyl chloride was observed above $850^{\circ}C$ in $CC1_4$/$H_2$ reaction system. The less chlorinated products are more stable, with methyl chloride the most stable chlorocarbon in this reaction system.

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Mechanism of Growth Inhibition by BCH in HEp2 Human Head and Neck Squamous Cell Carcinoma (사람 두경부 편평세포암종 HEp2 세포에서 BCH에 의한 세포성장 억제기전)

  • Choi, Bong-Kyu;Jung, Kyu-Yong;Cho, Seon-Ho;Kim, Chun-Sung;Kim, Do-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.5
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    • pp.555-560
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    • 2008
  • Amino acid transporters are essential for the growth and proliferation in all living cells. Among the amino acid transporters, the system L amino acid transporters are the major nutrient transport system responsible for the $Na^+$-independent transport of neutral amino acids including several essential amino acids. The L-type amino acid transporter 1 (LAT1), an isoform of system L amino acid transporter, is highly expressed in cancer cells to support their continuous growth and proliferation. 2-Aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) is a model compound for the study of amino acid transporter as a system L selective inhibitor. We have examined the effect and mechanism of BCH on cell growth suppression in HEp2 human head and neck squamous cell carcinoma. The BCH inhibited the L-leucine transport in a concentration-dependent manner with a $IC_{50}$ value of $51.2{\pm}3.8{\mu}M$ in HEp2 cells. The growth of HEp2 cells was inhibited by BCH in the timeand concentration-dependent manners. The formation of DNA ladder was not observed with BCH treatment in the cells. Furthermore, the proteolytic processing of caspase-3 and caspase-7 in the cells were not detected by BCH treatment. These results suggest that the BCH inhibits the growth of HEp2 human head and neck squamous cell carcinoma through the intracellular depletion of neutral amino acids for cell growth without apoptotic processing.

DNA Damage of Lipid Oxidation Products and Its Inhibition Mechanism (지질산화생성물의 DNA손상작용 및 그 억제기구)

  • KIM Seon-Bong;KANG Jin-Hoon;PARK Young-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.5
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    • pp.419-430
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    • 1987
  • The damage of plasmid DNA by lipid peroxidation and its inhibition were investigated through the model system of DNA and linoleic acid at $37^{\circ}C$. The degree of DNA damage increased in proportion to the increase of concentration and peroxidation of linoleic acid. DNA damage induced from linoleic acid peroxidation was greatly inhibited by the addition of active oxygen scavengers, especially, singlet of oxygen scavenge$(\alpha-tocopherol,\;cysteine)$ and superoxide anion scavenger(superoxide dismutase, ascorbic acid) in reaction system. These active oxygens, such as superoxide anion and hydrogen peroxide were rapidly generated in the early stage of peroxidation (POV below 100 mg/kg) and also scanvenged by the addition of superoxide dismutase and catalase, respectively. Hydroperoxide isolated from autoxidised linoleic acid showed DNA damage. Hydroperoxide induced-DNA damage was not inhibited by active oxygen scavengers. Lipid oxidation products, malonaldehyde and hexanal, also influenced on the DNA damage. Accordingly, it is speculated that DNA damage by lipid oxidation products is due to active oxygens such as singlet oxygen and superoxide anion formed in the early stage of peroxidation, direct action of hydroperoxide and formation of low molecular carbonyl compound-DNA complex. Furthermore, DNA damage induced by lipid peroxidation was remarkably inhibited by the addition of active oxygen scavengers and natural antioxidative fractions extracted from garlic and ginger. These antioxidative fractions also suppressed the generation of active orygens and linoleic acid oxidation. It is assumed that the inhibition of DNA damage by garlic and ginger extracts is due to the scavenging effect of active oxygens and the inhibition of hydroperoxide and oxidation products formation.

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Physiological Responses of Hairy Roots of Ginseng (Panax ginseng C.A. Meyer) to Iron Status and pH Change (배지의 철이온과 pH 변화에 대한 인삼모상근의 생리적 반응)

  • 양덕조;윤길영;김용해;양덕춘
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.1
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    • pp.31-37
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    • 2000
  • Proton extrusion by hairy roots of Panax ginseng C.A. Meyer was enhanced by iron-deficiency or single salt solutions of nitrate or ammonium salts. The enhancement effect of iron-deficiency was confined to the apical zones, whereas that of nitrate and ammonium was confined to the basal root zones. tinder iron-deficiency medium, the proton extrusion of ginseng hairy roots was higher at two times than that grown in the medium of iron-sufficiency. According to pH in the medium, uptake of inorganic elements showed various patterns for the kind of inorganic elements. $Ca^{2+}$, $Mg^{2+}$ and Fe$^{2+}$ were highest uptake at the pH 4.8 and Mn$^{2+}$, Zn$^{2+}$ and Cu$^{2+}$ were highest uptake at the pH 3.8. Free sugars and ginsenosides were analyzed by HPLC. Five kinds of free sugars were indentified in ginseng hairy roots. Glucose, fructose and sucrose were a major sugar in ginseng hairy roots and contents of free sugars were highest at pH 6.8 and pH 4.8, respectively. The contents of ginsenosides and phenolic compounds were highest at pH 5.8. This physiological responses in ginseng hairy root indicated that it may well be a good model system for the study of mechanism of mobilization and uptake of inorganic elements related with the red-colored phenomenon in ginseng roots.

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High-efficiency and Rapid Agrobacterium-mediated genetic transformation method using germinating rice seeds (벼 발아초기 종자를 이용한 고효율 단기형질전환 방법)

  • Lee, Hye-Jung;Abdula, Sailila E.;Jee, Moo-Geun;Jang, Dae-Won;Cho, Yong-Gu
    • Journal of Plant Biotechnology
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    • v.38 no.4
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    • pp.251-257
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    • 2011
  • Rice is the most important crop as a model plant for functional genomics of monocotyledons. Rice is usually transformed using Agrobacterium tumefaciens. However, the transformation efficiency using previous method is still low. In this study, we established a new method by modifying the general Agrobacterium protocol especially in the inoculation and co-cultivation step. We directly inoculated Agrobacterium containing a CIPK15 gene under the control of CaMV 35S promoter and NOS terminator in the pCAM1300 vector into the pre-soaked seeds in N6D media for 24 hours. After 7 days of culture at $25^{\circ}C$, calli were formed on seeds cultured on the co-cultivation medium containing an antioxidant compound (1 mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (3 mg/L silver nitrate). We obtained 35 and 22 transgenic plants in rice cultivars, Gopumbyeo and Ilpumbyeo, with increase of transformation efficiency by 30.4% and 22.6%, respectively compared to the general transformation method. The new method in this study would lead to reduction of substantial labor and time to generate transgenic plants.

Morphometric Study on Regeneration of Vascularized Nerve Graft (혈행화 신경이식 후 신경재생에 대한 형태계측학적 연구)

  • Tark, Kwan-Chul;Ahn, Sung-Jun;Kim, Dae-Yong;Lee, Young-Ho
    • Archives of Reconstructive Microsurgery
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    • v.6 no.1
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    • pp.9-28
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    • 1997
  • Adequate vascularization is pivotally essential for a successful nerve graft. Theoretically, the immediate vascularization will inhibit fibroblast infiltration and stimulate nerve cell regeneration. In this study, histomorphological and electrophysiological studies were performed to determine if vascularized grafts are functionally superior. In rat model, a 4cm segment of the sciatic nerve was obtained and placed as a non vascularized graft on one side, and as a vascularized graft connected to the inferior gluteal vessels on the opposite side. To determine the compound action potential of the gastrocnemius muscle, electromyography was done after 2, 3 and 4 months. Histomorphologically, the distribution of myelinated nerve fibers and Schwann cell were evaluated after toluidine blue staining, The following resutls were obtained: 1. The electrophysiological studies showed no difference between the nonvascularized and vascularized grafts. 2. Two and three months after grafting, myelinated nerve fibers were more abundant in the vascularized proximal, middle and distal areas in all nerve fibers of varying diameters. 3. In the post-nonvascularized graft 2-month group, a few myelinated nerve fibers were present in the proximal and middle areas, but none distally. In the post-vascularized graft 2 month group, myelinated nerve fibers ranging $2-8{\mu}m$ were present in all three areas. 4. In the post-nonvascularized graft 3 month group, a few myelinated nerve fibers ranging in $2-6{\mu}m$ were present in all three areas, but in the post-vascularized graft 3 month group, many myelinated nerve fibers ranging in $2-10{\mu}m$ were present in all three areas. 5. In the post-graft 4-month group, more myelinated nerve fibers were present in all three areas of the vascularized grafts. However, nerve fibers of less than $2{\mu}m$ in diameter were more abundant in the non vascularized grafts. 6. Schwann cells were more abundant in the proximal, middle and distal areas of the post-vascularized 2, 3 and 4-month grafts. Based on these findings, the immediate restoration of circulation in vascularized nerve grafts allows for the increased number of surviving Schwann cells, rapid healing of the axon and myelin sheath changes which occur during Wallerian degeneration, and thus is able to stimulate a morphologically optimal regeneration.

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A study on development of CRM by means of XRF analysis for fine ceramic ($BaTiO_3$) (티탄산바륨 소재의 XRF 분석용 CRM 개발에 관한 연구)

  • Kim, Young Man;Jeong, Chan Yee;Lim, Chang Ho;Song, Taek Yong;Lee, Dong Soo
    • Analytical Science and Technology
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    • v.9 no.4
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    • pp.382-391
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    • 1996
  • In this study, 12 different chemical species of fine ceramic($BaTiO_3$) were synthesized as the standard materials for the fast and accurate measurements of X-ray fluorescence spectrometry. Samples were diluted to sixteen times with the filling compound ($Li_2B_4O_7+LiBO_2$) in order to remove the matrix effect, and to get the convenient storage and homogeneity of ingredients. The matrix effects among the ingredients were corrected by the empirical coefficient method based on the Lucas-Tooth and Price model. The standard curve on 12 standard materials containing 15 elements were obtained by using X-ray fluorescence spectrometry at three different laboratories. The correlation factors of BaO, PbO, SrO, $Fe_2O_3$, $La_2O_3$, $SnO_2$, ZnO, $ZrO_2$, CaO indicated the relati vely good agreement over 0.995 among the three different laboratories. $SiO_2$ and $Al_2O_3$ showed the poor linearity because of their low fluorescence intensities.

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A Study on Costume Designer in Cinema (영화 의상 디자이너에 관한 연구)

  • Lee Hee-Hyun;Lee Yu-Kyung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.7 no.3
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    • pp.63-74
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    • 2005
  • The cinema costume designers carry out the creative works in a different way from the commercial fashion designers generating the new trends by season or year for a number of people. Costumes created by the cinema costume designers are for the people acting in the film screens such as heroes, heroines or extras. The cinema costume designers should not miss the overall flow of a cinema. Moreover, the prominent designers have to devise the costumes livening up every scene. Most cinemas with the prudent interests and attention on the costumes are favored by the public and gain the commercial success. In particular, the cinemas emphasize the visual effects such as setting, lighting and computer graphics and require the substantial budgets for preparing the costumes regardless of genres, while all other industrial fields will be the same. Such efforts are to deliver the meaning and aesthetics that the cinemas intend to show through the designs, colors and textures of costumes closed up in each scene. The costumes in cinemas are another linguistic system and have the symbolic form of compound and meaningful communication used by the directors. The costume design is required to produce the costumes that liven up the characteristics of heroes or heroines as well as to fit for the general artistic effects of films. Moreover, it has to express the characters in the films using the costumes suitable for the film genres. Cinema costumes are defined and refined, and the process can be angst-ridden. Each frame of film is a canvas and has its own proscenuium. Every garment worn in a theatrical production is a costume. Before an actor speaks, his wardrobe has already spoken for him. From the most obvious and flamboyant show clothing, to contemporary clothes using subtle design language, costume design plays an integral part in every film production. Costume design is a vital tool for storytelling. Costumes have always had enormous influence on world fashion. Costume designers are passionate storytellers, historians, social commentators, humorists, psychologists, trendsetters and magicians who can conjure glamour and codify icons. Costume designers are project managers who have to juggle ever-decreasing wardrobe budgets and battle the economic realities of film production. Costume designers are artists with pen and paper, form, fabric and the human figure.

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Desorption of organic Compounds from the Simulated Soils by Soil Vapor Extraction (인공토양으로부터 토양증기추출법에 의한 유기화합물의 탈착 현상에 관한 실험 연구)

  • 이병환;이종협
    • Journal of Korea Soil Environment Society
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    • v.3 no.2
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    • pp.101-114
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    • 1998
  • Soil vapor extraction (SVE) is known to be an effective process to remove the contaminants from the soils by enhancing the vaporization of organic compounds using forced vapor flows or applying vacuum through soils. Experiments are carried out to investigate the effects of the organic contaminants, types of soils, and water contents on the removal efficiency with operating time. In the study, simulated soils include the glass bead which has no micropore, sand and molecular sieve which has a large volume of micropores. As model organic pollutants, toluene, methyl ethyl ketone, and trichloroethylene are selected. Desorption experiments are conducted by flowing nitrogen gas. Under the experimental conditions, it is found that there are linear relationships between logarithm of removal efficiency and logarithm of number of pore volumes. The number of pore volumes are defined as the total amount of air flow through the soil column divided by the pore volume of soil column. For three organic compounds studied, the removal rate is slow for no water content, while the number of pore volumes for removal of organic compounds are notably reduced for water contents up to 37%. For the removal of dense organic compound, such as trichloroethylene, a large number of pore volumes are needed. Also, the effects of the characteristics of simulated soils on the removal efficiency of organic compounds are studied. After the characterization of soil surface, porosity of soil columns and types of contaminants, the results could provide a basis for the design of SVE process.

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Histopathologic Features and CD5+ B-lymphocyte Expression in the Experimental Allergic Neuritis (실험적 자가면역성 말초신경염에서의 조직병리적 병변 및 CD5+ B-림프구의 발현)

  • Cho, Joong-Yang;Choi, Won-Jun;Kim, Sung-Hun;Sung, Jung-Joon;Kim, Ho-Jin;Park, Kyung-Seok;Choi, Ki-Young;Kim, Hyun-Jung;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
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    • v.1 no.2
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    • pp.91-98
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    • 1999
  • Background : The pathogenesis of acute inflammatory demyelinating polyradiculoneuropathy (AIDP), Guillain Barre syndrome (GBS) is not clear, but it has been known that the immune mechanisms play an important role. Authors performed this study to establish an animal model of experimental allergic neuritis (EAN) by immunizing the myelin components of peripheral nerves and to understand the electrophysiological and histopathological features as well as the ${CD_5}^+$ B-lymphocyte changes in peripheral bloods in the EAN models. Methods : Lewis rats weighing 150-200 gm were injected subcutaneously in soles two times with total myelin, P0, P1, or P2 proteins purified from the bovine cauda eguina. The EAN induction was assessed by evaluating clinical manifestations. The electrophysiological and histopathological features were studied as routine methods. The ${CD_5}^+$ Blymphocytes were double stained using monoclonal FITC conjugated anti-rat CD45RA and R-PE conjugated anti-rat ${CD_5}^+$ antibodies and calculated using a fluorescence activated cell sorter (FACS). Results : The EAN animal models were established. In two out of five, in one out of two, in none out of three, and in none out of one Lewis rats injected with purified total myelin, P0, P1, P2 proteins respectively, They showed slow spontaneous motor activity and weak resistance against pulling back by tails. The typical electrophysiological and histologic findings in total protein and P0 induced EAN animal models were the decreased conduction velocity, the decreased compound muscle action potential (CMAP) amplitude and the dispersion phenomenon. The perivascular infiltrates of lymphocytes with focal demyelinating process were found in light microscopy. The ${CD_5}^+$ B-lymphocyte expression in three EANs were 2.38%, 3.50% 2.50%, which were not significantly increased, compared with those in normal controls. Conclusion : The EAN animal models were successfully established by injecting the total myelin and P0 myelin and they showed electrophysiological and histological features typical of demyelinating process. However they did not show an increased expression of ${CD_5}^+$ B-lymphocyte in peripheral bloods which could be indirect evidence of humoral autoimmunity.

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