• Title/Summary/Keyword: Chain Reaction

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Synthesis of Side-Chain Nonlinear Optical Polymers with Carbazolylnitrostilbene Chromophores

  • 김동욱;홍성일;박수영;김낙중
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.198-203
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    • 1997
  • Two different carbazolylnitrostilbene chromophores with second-order nonlinear optical (NLO) activity were newly synthesized by the reaction of 9-(2-hydroxyethyl)-9H-carbazol-3-carbaldehyde with 4-nitrophenylacetonitrile or 4-nitrophenylacetic acid. The NLO monomers were obtained by reaction of these chromophores with methacryloyl chloride. The side-chain nonlinear optical polymers were synthesized by the copolymerization of NLO monomer with methylmethacrylate using a free radical initiator. The chemical structures of the polymers were identified by spectroscopic means and the polymer properties such as molecular weight, Tg, solubility, UV-visible absorption, and second-harmonic generation (SHG) coefficients were investigated.

Optimized Substrate Concentrations for Production of Long-Chain Isomaltooligosaccharides Using Dextransucrase of Leuconostoc mesenteroides B-512F

  • Lee, Min-Sung;Cho, Seung-Kee;Eom, Hyun-Ju;Kim, So-Young;Kim, Tae-Jip;Han, Nam-Soo
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1141-1145
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    • 2008
  • Isomaltooligosaccharide (IMO) is a promising dietary component with prebiotic effect, and the long-chain IMOs are preferred to short chain ones owing to the longer persistence in the colon. To establish the optimal process for synthesis of long-chain IMOs, we systematically examined the reaction condition of dextransucrase of Leuconostoc mesenteroides B-512F by changing the ratio of sucrose to maltose (varying as 1:4, 1:2, 1:1, and 2:1) and amount of each sugar (from 2% to 20%). As a result, a ratio of 2:1 (sucrose to maltose, 10:5% or 20:10%, w/v) was determined as an optimal condition for long-chain IMO synthesis (DP3-DP9) with relatively higher yields (70-90%, respectively).

6-Methoxyluteolin from Chrysanthemum zawadskii var. latilobum Suppresses Histamine Release and Calcium Influx via Down-Regulation of $Fc{\varepsilon}RI$ ${\alpha}$ Chain Expression

  • Shim, Sun-Yup;Park, Jeong-Ro;Byun, Dae-Seok
    • Journal of Microbiology and Biotechnology
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    • v.22 no.5
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    • pp.622-627
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    • 2012
  • Mast cells and basophils are important effector cells in immunoglobulin-E (IgE)-mediated allergic reactions. Using the human basophilic KU812F cells, we assessed the inhibitory effects of 6-methoxyluteolin, isolated from Chrysanthemum zawadskii, in the $Fc{\varepsilon}RI$-mediated allergic reaction. We determined that 6-methoxyluteolin inhibited anti-$Fc{\varepsilon}RI$ ${\alpha}$ chain antibody (CRA-1)-induced histamine release, as well as elevation of intracellular calcium concentration $[Ca^{2+}]_i$ in a dose-dependent manner. Moreover, the inhibitory effects of 6-methoxyluteolin on the cell surface expression and the mRNA level of the $Fc{\varepsilon}RI$ ${\alpha}$ chain were determined by flow cytometric analysis and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Therefore, these results show that 6-methoxyluteolin is a potent inhibitor of histamine release and calcium influx via down-regulation of the $Fc{\varepsilon}RI$ ${\alpha}$ chain.

Development of Multiplex Polymerase Chain Reaction Assay for Identification of Angelica Species (Multiplex Polymerase Chain Reaction을 이용한 당귀 종 판별)

  • Kim, Yong Sang;Park, Hyeok Joo;Lee, Dong Hee;Kim, Hyun Kyu
    • Korean Journal of Medicinal Crop Science
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    • v.26 no.1
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    • pp.26-31
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    • 2018
  • Background: Angelica gigas, A. sinensis, and A. acutiloba are commercially important in the herbal medicine market, and among them, A. gigas has the highest economic value and price. However, their similar morphological traits are often used for fraud. Despite their importance in herbal medicine, recognition of the differences between Angelica species is currently inadequate. Methods and Results: A multiplex polymerase chain reaction (PCR) method was developed for direct detection and identification of A. gigas, A. sinensis, and A. acutiloba. The gene for the distinction of species was targeted at ITS in the nucleus and trnC-petN gene in chloroplasts. The optimized multiplex PCR in the present study utilized each Angelica species-specific primer pairs. Each primer pair yielded products of 229 base pairs (bp) for A. gigas, 53 bp for A. sinensis, 170 bp for A. acutiloba. Additionally non-specific PCR products were not detected in similar species by species-specific primers. Conclusions: In the present study, a multiplex-PCR assay, successfully assessed the authenticity of Angelica species (A. gigas, A. sinensis, and A. acutiloba). and whole genome amplification (WGA) was performed after DNA extraction to identify, the species in the product. The detection method of raw materials developed in the present study could be applied to herbal medicine and health functional food management.

Development of Duplex PCR Method for Simultaneous Detection of Rabbit (Oryctolagus cuniculus) and Cat (Felis catus) Meats (Duplex PCR을 이용한 토끼(Oryctolagus cuniculus)와 고양이(Felis catus) 육류의 동시 검출법 개발)

  • Hong, Yeun;Kim, Mi-Ju;Yang, Seung-Min;Yoo, In-Suk;Kim, Hae-Yeong
    • Journal of Applied Biological Chemistry
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    • v.58 no.4
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    • pp.383-387
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    • 2015
  • A duplex polymerase chain reaction (PCR) detection method was developed to authenticate the use of cat and rabbit in food and to prevent unlawful distribution of illegally butchered meat in both domestic and imported food market. Species-specific primers were designed targeting mitochondrial cytochrome b gene. The sizes of PCR products were 191 bp for cat and 101 bp for rabbit, which were relatively small for better application of the detection method on processed foods. Specificities of primers were verified using 21 animal species including cat and rabbit. Limit of detection was examined by serial dilution of the sample DNA and confirmed as 0.005 ng for rabbit and 0.0005 ng for cat using Bioanalyzer. The developed duplex PCR method showed specificity and sensitivity in the identification of two target species.

Detection of Toxoplasma gondii in experimentally infected porcine blood and tissues by polymerase chain reaction (Polymerase chain reaction을 이용한 실험적 감염 돼지의 혈액과 조직으로부터 Toxoplasma gondii 검출)

  • Suh, Myung-deuk;Shin, Gee-wook
    • Korean Journal of Veterinary Research
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    • v.41 no.1
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    • pp.89-98
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    • 2001
  • This study was conducted to detect the toxoplasma specific-DNA in circulating blood and organs collected from slaughtered pigs at slaughtering house and experimentally infected pigs with Toxoplasma gondii tachyzoites by polymerase chain reaction(PCR), and also PCR was applied to diagnose for acute phase of swine toxoplasmosis as a newly developed diagnostic test. The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with Tp parasite detection by mouse inoculation(MI). On the other hand, latex agglutination test(LAT) was conducted to detect the serum antibodies comparing with the detection of toxoplasma by PCR and MI. The results obtained were summarized as follows. PCR was able to determine at the lowest level of $10^0/ml$ T. gondii in blood samples which were blended with a serial diluted T gondii in vitro. On the other hand, $10^2/5g$ of T gondii could detect from a variety of tissues including lung, diaphragm, liver, heart, spleen and brain in vitro. The primer was proved to specifically determine T gondii in blood and tissues in vitro but it did not detect Neospora caninum used as a negative control. DNA of T. gondii was effectively extracted by freezing, thawing and grinding twice both tissues mixed with T gondii in vitro and in experimentally infected pig's tissues. PCR detected specific DNA in the blood of experimentally infected pigs at 108 hrs and 120 hrs post-infection, it was the same time that the pigs showed fever and parasitaemia. In case of tissue, specific DNA was, however, detected only lung from experimentally infected pigs. Even though the duration of acute phase was from 3 to 7 days post-infection, but the latex agglutination test (LAT) results appeared from 8 days post-infection. A comparison of sensitivity in determining T gondii in blood samples between PCR and MI, PCR positive rate ranged from 25 to 33.3%, but that of MI covered from 75 to 100%.

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Application of a nested-polymerase chain reaction assay to differentiate the genotypes of porcine circovirus 2 (돼지 써코바이러스 2형 유전형 분류를 위한 nested-PCR 적용)

  • Chu, Keum-Suk
    • Korean Journal of Veterinary Service
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    • v.34 no.1
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    • pp.13-18
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    • 2011
  • The purpose of this study was to apply a nested-polymerase chain reaction (nPCR) assay to detect and differentiate PCV 2a and PCV 2b. The compared with nPCR and one-step PCR and nPCR showed more sensitive in the detection of PCV-2 from tissue and blood samples. The total of 52 tissue samples was collected from postweanning pigs from 2006 to 2010. All tissue samples showed positive for PCV-2 in one-step PCR and nPCR, followed by the nPCR in order to identify the genotypes of PCV-2. 2 samples (3.8%) showed positive for PCV 2a, and 35 samples were positive for PCV 2b (67.3%), 15 samples (28.9%) were positive the dual genotypes. In addition, 42 blood samples which were collected from the 5 different swine farms were compared figure out the detection rates of nPCR and one-step PCR. The PCV 2 was positive by one-step PCR in 21 samples (50.0%) and nPCR was positive in 37 samples (88.1%). The PCV 2 genotypes in blood samples and 32 samples (76.2%) were positive for PCV 2b and none were positive for PCV 2a, 5 samples (11.9%) were positive for dual genotypes. These results suggest that the nPCR is very efficient for genotyping blood samples and differentiating the genotypes of PCV-2 from field samples.

A rapid detection of Salmonella species using polymerization chain reaction and Southern hybridization (Polymerization chain reaction과 Southern hybridization을 이용한 Salmonella속 균의 신속한 검출)

  • Kim, Won-yong;Chang, Young-hyo;Park, Kyoung-yoon;Kim, Chul-joong;Shin, Kwang-soon;Park, Yong-ha
    • Korean Journal of Veterinary Research
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    • v.35 no.3
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    • pp.531-536
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    • 1995
  • Salmonella species are the most prevalent etiologic agents of food-borne acute gastroenteritis. Direct isolation of bacteria from the contaminated food, stool and animal tissues has been used for the diagnosis of salmonellosis routinely. However, isolation of bacteria is time consuming work and not so highly sensitive. In recent years, improved methods of polymerization chain reaction(PCR) and probe hybridization technique have led to the developement of diagnostic assays which employ to detect various human and animal pathogenic bacteria. In this study, we have performed the polymerization chain reaction to detect Salmonella pullorum from tissues and stool samples of chickens with two specific primers, ST5 and ST8C. The target DNA fragment of PhoE gene was successfully amplified from liver, spleen, pancreas, heart, lung, ovary, oviduct and feces samples. The amplified DNA fragments were hybridized with Salmonella typhymurium TA3000 PhoE probe by Southern hybridization. The PCR to amplify the PhoE gene was highly rapid and sensitive method to detect Salmonella pullorum from tissues and stool samples.

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Optimization of ultra-fast convection polymerase chain reaction conditions for pathogen detection with nucleic acid lateral flow immunoassay

  • Kim, Tae-Hoon;Hwang, Hyun Jin;Kim, Jeong Hee
    • International Journal of Oral Biology
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    • v.44 no.1
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    • pp.8-13
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    • 2019
  • Recently, the importance of on-site detection of pathogens has drawn attention in the field of molecular diagnostics. Unlike in a laboratory environment, on-site detection of pathogens is performed under limited resources. In this study, we tried to optimize the experimental conditions for on-site detection of pathogens using a combination of ultra-fast convection polymerase chain reaction (cPCR), which does not require regular electricity, and nucleic acid lateral flow (NALF) immunoassay. Salmonella species was used as the model pathogen. DNA was amplified within 21 minutes (equivalent to 30 cycles of polymerase chain reaction) using ultra-fast cPCR, and the amplified DNA was detected within approximately 5 minutes using NALF immunoassay with nucleic acid detection (NAD) cassettes. In order to avoid false-positive results with NAD cassettes, we reduced the primer concentration or ultra-fast cPCR run time. For singleplex ultra-fast cPCR, the primer concentration needed to be lowered to $3{\mu}M$ or the run time needed to be reduced to 14 minutes. For duplex ultra-fast cPCR, $2{\mu}M$ of each primer set needed to be used or the run time needed to be reduced to 14 minutes. Under the conditions optimized in this study, the combination of ultra-fast cPCR and NALF immunoassay can be applied to on-site detection of pathogens. The combination can be easily applied to the detection of oral pathogens.