• Title/Summary/Keyword: Biological agent

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Synthesis of 2-Thio-4-aminopyrimidine Derivatives as Anti-cancer Agent

  • Lee, Sang-Hyo;Lee, Jin-Ho
    • Biomedical Science Letters
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    • v.15 no.2
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    • pp.105-112
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    • 2009
  • The screening of the anti-cancer activity of the chemical library provided 2-thio-4-aminopyrimidine as the initial hit. The confirmation of structure and biological effect of hit was performed by synthesis and biological evaluation. The optimization of hit was performed by derivatization of substituents while keeping the core structure. The evaluation of growth inhibitory activity was carried out using SRB assay against 6 human cancer cell lines and human fibroblast. The growth inhibitory activity of compounds showed substituent dependency and more than 5 compounds showed complete growth inhibition of cancer cell lines at 10 ${\mu}M$ concentration. Chemical library screening followed by synthetic modification provided possibility that 2-thio-4-aminopyrimidine can be used as a new scaffold for the development of anti-cancer agent.

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Ultrastructural Changes of Seminiferous Tubules in the Mouse by Alkylating Agent (Alkylating Agent에 의한 Mouse 정세관의 미세구조 변화)

  • Min, Soon
    • Journal of Korean Biological Nursing Science
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    • v.1 no.1
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    • pp.42-55
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    • 1999
  • The purpose of this study was to investigate the effect of cyclophosphamide on the mouse seminiferous tubules by transmission electron microscopy at different groups: a control group, a group treated one time a week, and a group treated two times a week. Cyclophosphamide was injected in the intraperitoneal at a dosage of level 200mg/kg. The results obtained were as follows. 1. In the group of one time a week, pyknotic body and large vesicles were observed in cytoplasm of spermatogonium of seminiferous tubules, and in the intercellular space between spermatocytes, respectively. 2. In the group of two times a week, nucleus envelope in the spermatid was disrupted partially, observed vesicles in the nucleoplasm of spermatid, and separated or disrupted inner and outer membranes of mitochondria in the Sertoli cells.

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Effects of Organoclay on the Thermal Insulating Properties of Rigid Polyurethane Foams Blown by Environmentally Friendly Blowing Agents

  • Kim, Youn-Hee;Choi, Seok-Jin;Kim, Ji-Mun;Han, Mi-Sun;Kim, Woo-Nyon;Bang, Kyu-Tae
    • Macromolecular Research
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    • v.15 no.7
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    • pp.676-681
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    • 2007
  • A process designed to synthesize rigid polyurethane foam (PUF) with insulative properties via the modulation of PUF cell size via the addition of clay and the application of ultrasound was assessed. The blowing agents utilized in this study include water, cyclopentane, and HFC-365mfc, all of which are known to be environmentally-friendly blowing agents. The rigid PUFs were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI) and polyether polyol with a density of $50kg/m^3$. In addition, rigid PUFs/clay nanocomposites were synthesized with clay modified by PMDI with and without the application of ultrasound. The PUF generated using water as a blowing agent evidenced the highest tensile strength. The tensile strength of the PUF/nanocomposites was higher than that of the neat PUF and the strength was even higher with the application of ultrasound. The cell size of the PUF/clay nanocomposites was less than that of the neat PUF, regardless of the type of blowing agent utilized. It appears that the higher tensile strength and lower cell size of the PUF/clay nanocomposites may be attributable to the uniform dispersion of the clay via ultrasonic agitation. The thermal conductivity of the PUF/clay nanocomposites generated with HCFC-141b evidenced the lowest value when PUF/clay nanocomposites were compared with other blowing agents, including HFC-365mfc, cyclopentane, and water. Ultrasound has also proven effective with regard to the reduction of the thermal conductivity of the PUF/clay nanocomposites with any of the blowing agents employed in this study. It has also been suggested that the uniformly dispersed clay particles in the PUF matrix function as diffusion barriers, which prevent the amelioration of the thermal insulation property.

Effect of Pichia anomala SKM-T and Galactomyces geotrichum SJM-59 Dipping on Storage Property and Sensory Quality of Strawberry

  • Mo, Eun-Kyoung;Sung, Chang-Keun
    • Food Science and Biotechnology
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    • v.14 no.4
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    • pp.487-492
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    • 2005
  • Simple competition plate bioassays of Pichia anomala SKM-T and Galactomyces geotrichum SJM-59 were conducted to evaluate their potential as biological control agents that inhibit growth of Botrytis cinerea during post-harvest storage of strawberries (Fragaria ${\times}$ ananassa Duche, Red-Pearl). Occurrence rates of fungi on the surface of yeast-treated strawberries were evaluated during storage at $4^{\circ}C$. P. anomala SKM-T and G. geotrichum SJM-59 showed antifungal activities on agar plate, and P. anomala SKM-T maintained its desirable antifungal activity on surface of strawberries and its physicochemical properties during storage. Sensory evaluation was based on kinesthetics and consumer acceptability. Due to its potential antifungal activity, P. anomala SKM-T could function as biological control agent against spoilage fungi during post-harvest storage of strawberries.

Study on Chemical-Biological Protection Performance of the CHEONGUNG's Integrated Protection Unit (천궁체계 교전/사격통제소용 종합식보호장치의 화생방호성능 평가 연구)

  • Shim, Woo-Sup;Ryu, Sam-Gon;Kwon, Tae-Geun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.1
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    • pp.75-80
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    • 2012
  • The integrated protection unit of CHEONGUNG is composed of chemical-biological equipment and air conditioner equiped heating element. The protection capabilities against chemical-biological agent were measured by using simulant agents such as n-Hexane, KM5 Screening Smokes and CS agent. The experimental test results with simulant agents verify the protective performance of the integrated protection unit.

In vitro Biological Control Against Trichoderma harzianum Using Antifungal Bacteria

  • Lee, Ho-Yong;Hyun, Soung-Hee
    • Korean Journal of Environmental Biology
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    • v.18 no.4
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    • pp.441-446
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    • 2000
  • Trichoderma harzianum is an aggressive causal agent of green mold disease on mushroom cultivation. Some bacterial strains isolated, from oyster mushroom compost in Wonju, were found to have in vitro antifungal activity against Trichoderma harzianum ATCC 6385, 6504, and our isolates Trichoderma spp. Y and G. Further in vitro antifungal studies on several strains of phytopathogenic fungi showed that all of 12 phytopathogenic fungal strains were significantly inhibited by the isolated antifungal bacteria in Petri dishes. Of these, KATB 99121 showed the broadest inhibiting effect and displayed as negative coagulase, negative sulfide production and rod shape. KATB 99121 was resistant to ampicillin, chlorampenicol, and kanamycin. Identification of isolates was determined by Biolog GN system, and KATB 99121 was identified as Photobacterium logei because of 96 probability, 0.65 similarity, and 4.97 disturbance. With electron microscopy, thin section of KATB 99121 strain revealed typical rod-like shaped cell (0.6-0.8${\mu}{\textrm}{m}$$\times$1.5-2.0${\mu}{\textrm}{m}$) with prokaryotic structure and organization.

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The First Study on Bacterial Flora and Biological Control Agent of Anoplus roboris (Sufr., Coleoptera)

  • Demirbag, Zihni;Sezen, Kazim;Demir, Ismail
    • Journal of Microbiology
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    • v.40 no.2
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    • pp.104-108
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    • 2002
  • The hazelnut leaf holer (Anoplus roboris Sufr,, Coleoptera: Curculionidae) is a devastating pest of hazelnut and oak trees. It causes approximately 20-30% economic damage to hazelnut production per year in Turkey. In the present study, in order to fond a more effective and safe biological control agent against A. roboris, we investigated the bacterial flora of the hazelnut leave holer, and tested them for insecticidal effects on it. According to morphological, physiological and biochemical tests bacterial flora were identified as Bacillus circulans (Ar1), Bacillus polymyxa (Ar2), Enterobacter sp. (Ar3) and Bacillus sphaelicus (Ar4). Insecticidal effects of bacterial isolates were performed on adult A. roboris. The highest insecticidal effect determined was 67% by B. sphaericus within eight days. The insecticidal effects of the other isolates (Ar1, Ar2 and Ar3) were determined as 33%, 47% and 47% within the same period, respectively.

Development of Alkaline Degreasing Agent for Electroplating Pretreatment Process (도금 전처리공정에서 맞춤형 알칼리계 탈지제 개발)

  • Lee, Seung-Bum;Joeng, Koo-Hyung;Lee, Jae-Dong
    • Applied Chemistry for Engineering
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    • v.21 no.3
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    • pp.301-305
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    • 2010
  • In this study, the alkaline degreasing agent was developed for electroplating pretreatment process, and the efficiency and the durability was predicted. The alkaline deeping degreasing agent was prepared by blending sodium hydroxide (NaOH), sodium carbonate ($Na_2CO_3$), sodium silicate ($Na_2SiO_3$), and sodium lauric sulfate (SLS). The performance tests of the degreasing agent were evaluated in the $40{\sim}50^{\circ}C$ of the degreasing temperature and 30~40 min of the degreasing time. The efficiency and durability of the prepared degreasing agent were tested by the waterdrop formation test and Hull-cell plating test. The optimum ratio of alkaline degreasing agent was NaOH (30 g/L) + SLS (6.0 g/L) + $Na_2SiO_3$ (2.0 g/L) + $Na_2CO_3$ (40 g/L). Also, the optimum degreasing conditions were $50^{\circ}C$ of the degreasing temperature and 35 min of the degreasing time.

Gold Nanoparticles Coated with Gd-Chelate as a Potential CT/MRI Bimodal Contrast Agent

  • Sk Md., Nasiruzzaman;Kim, Hee-Kyung;Park, Ji-Ae;Chang, Yong-Min;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1177-1181
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    • 2010
  • The synthesis and characterization of gold nanoparticles coated by Gd-chelate (GdL@Au) is described, where L is a conjugate of DTPA (DTPA = diethylenetriamine-N,N,N',N",N"-pentaacetic acid) and 4-aminothiophenol. These particles are obtained by the replacement of citrate from the gold nanoparticle surfaces with gadolinium chelate (GdL). The average size of GdL@Au is 12 nm with a loading of GdL reaching up to $1.4{\times}10^3$ per particles, and they demonstrate very high r1 relaxivity (${\sim}10^4mM^{-1}s^{-1}$) and the r1 relaxivity per [Gd] is as high as $10mM^{-1}s{-1}$. Here, we also describe the use of bimodality of this contrast agent (CA) as a highly efficient CT contrast agent based on gold nanoparticles (GNPs) that overcome the limitations of iodine based contrast agent. The MTT assay performed on this CAs reveals the cytotoxicity as low as that for Omniscan$^{(R)}$ in the concentration range required to obtain intensity enhancement in the in vivo MRI study.

Bactericidal Effect of Waterless Alcohol Gel Hand Washing Agent (물 없이 사용하는 알코올 젤의 손소독 효과에 관한 연구)

  • Jeong, Jae-Sim;Kim, Duck-Hee;Kim, Mi-Na;Choe, Myoung-Ae
    • Journal of Korean Biological Nursing Science
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    • v.4 no.2
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    • pp.127-137
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    • 2002
  • The purpose of this study was to compare the hand disinfection effect of waterless alcohol gel hand washing agent with that of soap and water, 4% chlorhexidine gluconate, and 10% povidone-iodine. Hands of fourty subjects were artificially contaminated with Acinetobacter baumannii $5m{\ell}$ and randomly distributed to each hand washing methods. Samples were collected from gloved hand by glove juice sampling procedure. Mean log reduction after hand washing were compared with baseline values. Number of microorganisms were converted to log and tested by ANOVA in SPSSWIN 10.0. Mean log reduction of soap and water, alcohol gel, 4% chlorhexidine gluconate, 10% povidone-iodine were $2.76{\pm}0.62$, $2.97{\pm}0.56$, $4.66{\pm}1.70$, $4.60{\pm}0.91$, respectively. The bactericidal effect of alcohol gel was similar to that of soap and water, but the effect was much less than chlorhexidine gluconate and povidone-iodine(p<0.001). In terms of microorganism reduction, the efficacy of waterless alcohol gel was almost the same as soap and water hand washing. Further evaluation of the bactericidal effect of waterless alcohol gel is needed because waterless alcohol gel is simple, convenient, and non-irritating hand washing agent and also very effective in busy hospital environment.

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