• 제목/요약/키워드: synthetic variety

검색결과 209건 처리시간 0.024초

High Throughput Screening for Natural Products to Find Biologically Active Compounds : Natural Products versus Combinatorial Chemistry

  • Sankawa, Ushio
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 한국응용약물학회 1997년도 추계학술대회
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    • pp.47-50
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    • 1997
  • Drug development began with the finding of biologically active compounds which are obtained by chemical synthesis or from natural sources. The advent of Combinatorial Chemistry is recognized as a strategy which has a potential to change the methodology of research and development(R&D) of new drugs. Drug development has been carried out with diverse strategies. In the past several decades a variety of new methodology have been introduced in R&D. Random screening of accumulated synthetic samples which had been synthesized for development of other drugs led to the discovery of new drugs. The typical examples are anti-asthma drug trimethoquinol and calcium antagonist diltiazem. (herbesser). In particular the latter drug has been used as a calcium antagonist worldwide, however it was first synthesized to find new tranquilizer and this is the reason why diltiazem has benzodiazepam skeleton. The random screening contributed in the finding of new drugs were carried out with whole animal test and it is a standard methodology in R&D of new drugs. Aspirin is the first synthetic non-steroidal antiinflammatory drug(NSAID) and has been used for more than one hundred years. It is the first example of drug developed from natural product. Salicin is the main constituent of willow bark which had been used in Europe for a long time to treat arthritis and aspirin was developed from salicin. Most of NSAID used clinically were developed from the structure of aspirin, however it took 70 years to clarify why aspirin exhibits its antiinflammatory, analgesic and antipyretic activities. The target of aspirin is cyclooxygenase(COX)which is the first enzyme involved in arachidonate cascade leading to the production of prostaglandins(PG) and thromboxan(TX). Side effect of aspirin causing ulcer in stomach is rather serious problem, since aspirin is so popular drug easily obtained in drug store(OTP). This problem is now going to be solved by a new finding on COX, which have two different types, one is constitutionally expressed COX 1 in almost all organs and the other is inducible COX 2. COX 2 is the responsible enzyme in inflammation etc and now the search of COX 2 specific inhibitors is the target of R&D of next generation NSAID.

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Application of Bimodal Histogram Method to Oil Spill Detection from a Satellite Synthetic Aperture Radar Image

  • Kim, Tae-Sung;Park, Kyung-Ae;Lee, Min-Sun;Park, Jae-Jin;Hong, Sungwook;Kim, Kum-Lan;Chang, Eunmi
    • Korean Journal of Remote Sensing
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    • 제29권6호
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    • pp.645-655
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    • 2013
  • As one of segmentation techniques for Synthetic Aperture Radar (SAR) image with oil spill, we applied a bimodal histogram method to discriminate oil pixels from non-oil pixels. The threshold of each moving window was objectively determined using the two peaks in the histogram distribution of backscattering coefficients from ENVISAT ASAR image. To reduce the effect of wind speed on oil spill detection, we selected ASAR image which satisfied a limit of wind speeds for successful detection. Overall, a commonly used adaptive threshold method has been applied with a subjectively-determined single threshold. In contrast, the bimodal histogram method utilized herein produces a variety of thresholds objectively for each moving window by considering the characteristics of statistical distribution of backscattering coefficients. Comparison between the two methods revealed that the bimodal histogram method exhibited no significant difference in terms of performance when compared to the adaptive threshold method, except for around the edges of dark oil spots. Thus, we anticipate that the objective method based on the bimodality of oil slicks may also be applicable to the detection of oil spills from other SAR imagery.

Macromolecular Docking Simulation to Identify Binding Site of FGB1 for Antifungal Compounds

  • Soundararajan, Prabhakaran;Sakkiah, Sugunadevi;Sivanesan, Iyyakkannu;Lee, Keun-Woo;Jeong, Byoung-Ryong
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3675-3681
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    • 2011
  • Fusarium oxysporum, an important pathogen that mainly causes vascular or fusarium wilt disease which leads to economic loss. Disruption of gene encoding a heterotrimeric G-protein-${\beta}$-subunit (FGB1), led to decreased intracellular cAMP levels, reduced pathogenicity, colony morphology, and germination. The plant defense protein, Nicotiana alata defensin (NaD1) displays potent antifungal activity against a variety of agronomically important filamentous fungi. In this paper, we performed a molecular modeling and docking studies to find vital amino acids which can interact with various antifungal compounds using Discovery Studio v2.5 and GRAMMX, respectively. The docking results from FGB1-NaD1 and FGB1-antifungal complexes, revealed the vital amino acids such as His64, Trp65, Ser194, Leu195, Gln237, Phe238, Val324 and Asn326, and suggested that the anidulafungin is a the good antifungal compound.The predicted interaction can greatly assist in understanding structural insights for studying the pathogen and host-component interactions.

Advanced Synthetic Technology for High Performance Energy Tire Tread Rubber (고성능 에너지 절약형 타이어 트레드 고무의 합성 제조 기술)

  • Lee, Bum-Jae;Lim, Ki-Won;Ji, Sang-Chul;Jung, Kwon-Young;Kim, Tae-Jung
    • Elastomers and Composites
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    • 제44권3호
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    • pp.232-243
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    • 2009
  • The specialized and diversified synthetic and compounding technologies are used to meet the requirements for the advanced high performance tire tread materials with better balance of fuel economy(rolling resistance), safety(wet traction) and wear resistance. These techniques involve the methodology for the improvement of chemical and physical interaction between filler and the rubber matrix using coupling agents as well as a variety of chemically-modified solution SBRs. The research trends about the high performance functional SBRs and coupling agents which can interact with the surface of fillers and their working mechanism were investigated in the conventional carbon black-filled rubber and silica-filled SBR systems developed recently as "green tire".

A Study on the Reaction Optimization for the Utilization of CO2 and CH4 from Bio-gas (바이오가스에서 CO2/CH4 활용에 관한 반응최적화 연구)

  • KHO, DONGHYUN;CHO, WOOKSANG;BAEK, YOUNGSOON
    • Journal of Hydrogen and New Energy
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    • 제27권5호
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    • pp.554-561
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    • 2016
  • Depending on the Bio-gas sources, main component gases of $CH_4$ and $CO_2$ are shown to be variously present in amounts. For the anaerobic digester, The concentration of $CH_4$ and $CO_2$ in the gases are 60~70 and 30~35 vol%. For the landfill gas, $CH_4$ and $CO_2$ are 40~60 and 40~60 vol%. For the food wastes, $CH_4$ and $CO_2$ are 60~80 and 20~40 vol%, respectively. In this study, maximum conversion rates of $CO_2$ were obtained from the variety of concentrations of $CH_4$ and $CO_2$ by the catalysts of reforming reactions. Moreover, in order to get maximum producing amount of synthetic gas, experimental studies were performed to optimize the reaction variables. On the basis of $CH_4$, 243 ml, R [$CH_4/(O2+CO_2)$] value were varied from 0.8 to 1.35, in the study of $CH_4$ and $CO_2$ reforming reactions. It was shown that the optimal results were obtained for 1.35 of R value. And also, at $850^{\circ}C$ and 1 atm, the production rate of synthetic gas was 90% and the conversion rates of $CH_4$ and $CO_2$ were higher than 99% and 90%, respectively.

Physiological Characteristics of Biosurfactant-Producting Bacillus subtilis TBM 3101 (Biosurfactant를 생산하는 Bacillus subtilis TBM 3101의 생리학적 특성)

  • Kim, Seon-A;Lee, Young-Guen;Choi, Yong-Lark;Hwang, Cher-Won;Jeong, Yong-Kee;Joo, Woo-Hong
    • Applied Biological Chemistry
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    • 제50권1호
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    • pp.12-17
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    • 2007
  • A biosurfactant-producing strain, Bacillus subtilis TBM 3101 was isolated from the soil sample at Tae-Baek Mountain through an antifungal test and emulsification assessment. The strain was assessed, regarding to the microbial growth, by physical and chemical test, surface tension, emulsification activity and stability. The surface tension of the isolate sharply decreased to the minimum 29mN/m at 48 h growth. Of note, its emulsification was stabilized to the highest degree when tributyrin was utilized as a substrate, indicating that in comparison to a variety of synthetic surfactants, the biosurfactant produced by the isolate was significantly similar to synthetic surfactant, tween 20. In addition, the biosurfactant showed high emulsification activity when soybean oil, crude oil and tetradecane were used as a substrate. Thus, these studies could contribute to the detection and development of biosurfactant beneficial to the environment and humans.

Investigation of SAR Systems, Technologies and Application Fields by a Statistical Analysis of SAR-related Journal Papers (SAR 관련 논문 통계 분석에 의한 SAR 시스템, 기술, 활용분야 고찰)

  • Lee Hoon-Yol
    • Korean Journal of Remote Sensing
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    • 제22권2호
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    • pp.153-174
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    • 2006
  • The purpose of this paper is to establish the category of SAR(Synthetic Aperture Radar) systems, technologies and application fields, thus to provide the world-wide trend in SAR research and development activities by analysing SAR-related journal papers. This paper presents an analysis result of SAR-related journal papers published from the late 1960s to early 2005. Abstracts and indices of 2665 peer-reviewed, English journal papers published in 243 journals were collected from the Cambridge Scientific Abstracts and classified into the categories according to the system, technique, and application field. Statistics on each category were provided so that one can understand the historical and on-going development in SAR systems, techniques, and a variety of application fields such as land, ocean, cryosphere and atmosphere. This statistical analysis data would be a valuable guideline to establish a future SAR system application and satellite manoeuvering policy in Korea.

Performance Analysis of Quad-pol SAR System for Wide-Swath Operation Mode (광역관측 운용 모드에 대한 Quad-pol SAR 시스템의 성능 분석)

  • Lim, Jung-Hwan;Yoon, Seong Sik;Lee, Jae-Wook;Lee, Taek-Kyung;Ryu, Sang-Burm;Lee, Hyeon-Cheol;Lee, Sang-Gyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제30권2호
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    • pp.141-151
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    • 2019
  • In this study, we propose a performance analysis of a quadrature-polarimetric(quad-pol) synthetic aperture radar(SAR) system for wide-swath operation mode and compare it with a single-pol system based on the operation mode. To achieve a shorter revisit time for an SAR satellite, we must observe a wide area, and two SAR operation modes exist for this purpose, which are called ScanSAR and SweepSAR. In general, a quad-pol SAR system can obtain a greater variety of information about a target than a single-pol system. Because this system affects system performance parameters, analyzing these effects is required. Based on a performance analysis of the wide-swath quad-pol SAR system, the system parameters and appropriate operation mode can be selected to satisfy the performance requirements.

A study on the Alteration of traditional costume of Korean Chinese (I) - Focused on the daily wear - (중국 조선족 전통복식의 변화연구 (I) - 일상복을 중심으로 -)

  • Lin, Huishun
    • Journal of the Korea Fashion and Costume Design Association
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    • 제22권4호
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    • pp.63-78
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    • 2020
  • Korean Chinese, immigrants to China, have developed their own traditional costume culture. This paper aims to analyze the traditional costume culture of the Korean Chinese and to provide data for posterity. The research methods are literature research, survey research, and analysis research. The results are as follows: According to the changes over generations, the top of women's Hanbok has changed in length as has the jeogori (jacket), the git (collar), and the gooreum (breast-tie). The width of the git, dong-jeong (thin white cloth-covered paper collar of Hanbok), the sleeve, and gooreum have also changed. The git and the barae (the curve part of the sleeve) have changed from straight patterns to curves. The skirt had changed in wrinkles arrangement, length, and silhouette. The men's Hanbok jeogori and sleeves were lengthened; the pants became wider and were lengthened, and the collar also became curved. The vest has not changed and the du-ru-ma-gi (coat) that once disappeared is being worn again; the bae-ja (vest) and magoja (over-jacket) are worn frequently in modern times. The garments mainly used natural fiber until the development of synthetic fibers, but the treand has been the use of luxurious natural fibers in modern times. The initial color pattern was achromatic, but that changed with the appearance of synthetic fibers, and nowadays it is mainly the garmetnt can display a variety of colors. In addition, hairstyles and shoes have been eveolved from traditional to modern styles.

A Stress-Tolerant and High-Yielding Tall Fescue New Variety, 'Greenmaster' (내재해 다수성 톨 페스큐 신품종 "그린마스터"의 품종 특성)

  • Choi, Gi-Jun;Lim, Young-Chul;Ji, Hee-Chung;Kim, Ki-Yong;Park, Hyung-Soo;Seo, Sung;Moon, Chung-Sup;Kim, Dae-Ho;Lee, Sang-Hoon
    • Journal of The Korean Society of Grassland and Forage Science
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    • 제30권3호
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    • pp.199-204
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    • 2010
  • A new tall fescue variety (Festuca arundinacea Schreb.) named "Greenmaster" was developed by the National Institute of Animal Science, RDA, at Suwon from 1999 to 2007. For synthetic seed production of this new variety, 5 superior clones, EFa9111, EFa9122, EFa9211, EFa9225, and EFa9234 were selected and polycrossed. The agronomic growth characteristics and forage production capability of the seeds were studied at Suwon from 2003 to 2004, and regional trials were conducted in Suwon, Pyungchang, Jeju, and Ikcsan from 2005 to 2007. Greenmaster showed enhanced winter hardiness, disease resistance, and regrowth ability as compared to Fawn. The dry matter yield of Greenmaster was 11% higher as 19,156 kg/ha than that of Fawn. However, the nutritive value of both varieties was similar.