• Title/Summary/Keyword: selective detection

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Determination of Ultra Trace Levels of Copper in Whole Blood by Adsorptive Stripping Voltammetry

  • Attar, Tarik;Harek, Yahia;Larabi, Lahcen
    • Journal of the Korean Chemical Society
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    • v.57 no.5
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    • pp.568-573
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    • 2013
  • A selective and sensitive method for simultaneous determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The procedure involves an adsorptive accumulation of Cu(II)-ETSC (4- ethyl-3-thiosemicarbazide) on a hanging mercury drop electrode, followed by a stripping voltammetry measurement of reduction current of adsorbed complex at about -715 mV. The optimum conditions for the analysis of copper (II) ion are : pH 10.3, concentration of 4-ethyl-3-thiosemicarbazide $3.25{\times}10^{-6}$ M and an accumulation potential of -100 mV. The peak current is proportional to the concentration of copper over the range 0.003-125 ng/mL with a detection limit of 0.001 ng/mL and an accumulation time of 60 s. Moreover, with the use of the proposed method, there is a considerable improvement in the detection limit, the linear dynamic range and the deposition time, compared with the methods of adsorptive stripping voltammetry for the determination of copper. The developed method was validated by analysis of whole blood certified reference materials.

Microbial Extracellular Enzyme Detection on Agar Plates by Means of Fluorogenic Methylumbelliferyl-Substrates (Methylumbelliferyl 형광기질을 이용한 평판배지상의 미생물 체외 세포효소측정방법)

  • ;Hoppe, H.-G.
    • Korean Journal of Microbiology
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    • v.28 no.3
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    • pp.229-235
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    • 1990
  • A rapid and sensitive method to detect the extracellular enzymatic activity of bacteria colonies grown on agar plates is described. Selective agar media supplemented with protein, starch, chitin, Tween-80, etc. are conventionally used to detect biochemical properties of bacteria. It has been experimentally demonstrated with bacteria pure cultures that fluorogenic Methylumbelliferyl (MUF)-substrates are excellent substrate analogues for normally occurring polymers. Based on MUF-substrate hydrolysis the new method provides reliable qualitative estimates of extracellular enzymatic properties of bacteria within minutes using pure cultures as well as agar p;ates prepared for colony counts. Extracellular enzyme activities of heterotrophic bacteria from freshwater ecosystems and marine sediment using this method are discussed.

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Live Cell Detection of Monoclonal Antibody Light and Heavy Chain mRNAs using Molecular Beacons (분자 비컨을 이용한 살아 있는 세포에서 단일클론항체 경쇄와 중쇄 mRNA 검출에 의한 세포주 선별방법)

  • Jeong, Seunga;Rhee, Won Jong
    • KSBB Journal
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    • v.31 no.1
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    • pp.33-39
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    • 2016
  • Developing the method for the selection of animal cell line producing therapeutic monoclonal antibody (mAb) is invaluable as its market is rapidly growing. Although the quality of produced mAb is as important as quantity, however there is no method developed for the selective screening of cell lines on the basis of both quantity and quality. From recent reports, the ratio of light and heavy chain mRNAs of mAb in the cell is a key parameter for the indication of product quality. Therefore, it is obvious that developing the novel method that can detect both light and heavy chain mRNAs in single live cell will provide unprecedented opportunities in bio-industry. Here, we have constructed oligonucleotide probes, molecular beacons for the detection of light or heavy chain mRNAs, respectively, in the live cells producing mAbs. Both beacons showed increased fluorescent intensity after transient transfection of plasmid expressing mAbs analyzed by fluorometer. Flow cytometric analysis clearly demonstrated that both molecular beacons can simultaneously detect the expression of light and heavy chain mRNAs of mAb in the same cell. The technique described in the thesis provides the new direction and concept for developing the method for the smart selection of cell lines producing recombinant proteins including therapeutic mAbs.

Detection of QTLs Influencing Panicle Length, Panicle Grain Number and Panicle Grain Sterility in Rice(Oryza sativa L.)

  • Ahamadi, Jafar;Fotokian, M.H.;Fabriki-Orang, S.
    • Journal of Crop Science and Biotechnology
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    • v.11 no.3
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    • pp.163-170
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    • 2008
  • The detection, characterization and use of quantitative traits loci, QTL, have significant potential to improve the efficiency of selective breeding of species. Therefore, a population with 59 advanced backcross lines($BC_2F_5$), derived from a cross between IR64 and Tarome molaei, were studied in Tonekabon Rice Research Station of Iran in order to map QTLs for panicle length, number of grain per panicle, and panicle grain sterility in rice. The parental screening wtih 235 SSR markers in agarose and polyacrylamide gels revealed 114 markers with clear polymorphic bands. To search for QTLs associated with panicle length, number of grain per panicle, and panicle grain sterility, we constructed a genetic linkage map using 114 microsatellite markers. Positive and negative transgressive segregations were observed in $BC_2F_5$ lines for all traits. Using multiple interval mapping(MIM), a total of 20 putative QTLs were detected, of which eight were for panicle length, three for number of grains, and nine for panicle grain sterility. The maximum number of QTLs were mapped on chromosomes 1 and 2 with eight QTLs. These QTL markers could possible be utilized for marker-assisted selection.

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Detection of Pathogenic Salmonella with a Composite Quantum Dot (나노 양자점 결합을 이용한 살모넬라 식중독균 검출)

  • Kim, Gi-Young;Yang, Gil-Mo;Kim, Yung-Hwun;Moh, Chang-Yeon;Park, Saet-Byeol
    • Journal of Biosystems Engineering
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    • v.35 no.6
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    • pp.458-463
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    • 2010
  • It is required to develop rapid methods to identify pathogenic Salmonella in food products for protecting and maintaining safety of the public health from Salmonellosis. The objective of the present study was to explore feasibility of the nanotechnology to detect pathogenic Salmonella rapidly in various samples. Sensitivity of the a composite quantum dot to detect Salmonella typhimurium in samples were evaluated. For selective detection of Salmonella, anti-Salmonella polycolonal antibody was utilized to capture and stain Salmonella. Quantum dots were attached onto Salmonella in the samples and produced fluorescent light. Fluorescence response of the composite quantum dot was measured with a commercial fluorescence meter. The fluorescence signal starts to increase with the samples in which higher concentration of the cells were contained. The sensitivity of the sensor was $10^6\;CFU/mL$ Salmonella spiked in PBS.

A Study of End Point Detection Measurement for STI-CMP Applications (STI-CMP 공정 적용을 위한 연마 정지점 고찰)

  • 이경태;김상용;김창일;서용진;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.90-93
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    • 2000
  • In this study, the rise throughput and the stability in fabrication of device can be obtained by applying of CMP process to STI structure in 0.18um semiconductor device. To employ in STI CMP, the reverse moat process has been added thus the process became complex and the defects were seriously increased. Removal rates of each thin films in STI CMP was not equal hence the devices must to be effected, that is, the damage was occured in the device dimension in the case of excessive CMP process and the nitride film was remained on the device dimension in the case of insufficient CMP process than these defects affect the device characteristics. To resolve these problems, the development of slurry for CMP with high removal rate and high selectivity between each thin films was studied then it can be prevent the reasons of many defects by reasons of many defects by simplification of process that directly apply CMP process to STI structure without the reverse moat pattern process.

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Density Evolution Analysis of RS-A-SISO Algorithms for Serially Concatenated CPM over Fading Channels (페이딩 채널에서 직렬 결합 CPM (SCCPM)에 대한 RS-A-SISO 알고리즘과 확률 밀도 진화 분석)

  • Chung, Kyu-Hyuk;Heo, Jun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.7 s.337
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    • pp.27-34
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    • 2005
  • Iterative detection (ID) has proven to be a near-optimal solution for concatenated Finite State Machines (FSMs) with interleavers over an additive white Gaussian noise (AWGN) channel. When perfect channel state information (CSI) is not available at the receiver, an adaptive ID (AID) scheme is required to deal with the unknown, and possibly time-varying parameters. The basic building block for ID or AID is the soft-input soft-output (SISO) or adaptive SISO (A-SISO) module. In this paper, Reduced State SISO (RS-SISO) algorithms have been applied for complexity reduction of the A-SISO module. We show that serially concatenated CPM (SCCPM) with AID has turbo-like performance over fading ISI channels and also RS-A-SISO systems have large iteration gains. Various design options for RS-A-SISO algorithms are evaluated. Recently developed density evolution technique is used to analyze RS-A-SISO algorithms. We show that density evolution technique that is usually used for AWGN systems is also a good analysis tool for RS-A-SISO systems over frequency-selective fading channels.

Evaluation of enrichment broth and selective media for the detection of non-O157 enterohemorrhagic Escherichia coli (Non-O157 장출혈성대장균 검출을 위한 증균배지 및 선택배지 성능 평가)

  • Lee, Da Yeon;Kim, Hee-eon;Seo, Dong Won;Cho, Yong Sun
    • Korean Journal of Food Science and Technology
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    • v.48 no.4
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    • pp.323-328
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    • 2016
  • In this study, specific and rapid enrichment and growth conditions for the most important, classic non-O157 enterohemorrhagic Escherichia coli (EHEC) serogroups were assessed. Three enrichment broth types, namely, EC medium with MUG broth, BRILA broth, and mTSB broth with novobiocin, were compared to identify the optimum enrichment broth for EHEC isolation. Four kinds of selective media, namely, ENDO agar, Chromocult agar, TBX agar, and CHROMagar$^{TM}$ STEC medium, were compared to identify the optimum one for non-O157 EHEC isolation. The results suggested that incubation in EC medium with MUG broth at $42^{\circ}C$ for 20 h is optimum for the enrichment of non-O157 EHEC. TBX agar was identified to have the highest specificity among the tested media. Consequently, a combination of complementary selective media according to serotype must be considered for comprehensive isolation of specific EHEC.

One-component Room Temperature Vulcanizing-Type Silicone Rubber-Based Solid-State Carbonate Ion Selective Electrode (단일 조성 실온 경화형 실리콘러버를 지지체로 사용한 고체상 탄산이온선택성 전극의 개발)

  • Kim, Mi-Kyoung;Yoon, In-Jun;Cho, Sung-Ho;Shin, Hye-Ra;Han, Jong-Ho;Ha, Jeong-Han;Nam, Hak-Hyun;Cha, Geun-Sig
    • Journal of the Korean Chemical Society
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    • v.48 no.3
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    • pp.266-272
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    • 2004
  • We developed a miniaturized solid-state carbonate ion-selective electrode (carbonate ISE) based on one-component room temperature vulcanizing type silicone rubber 730 (730 RTV) without adding plasticizer to the matrix. The optimized carbonate ion selective membrane is prepared with 85.8 wt% of 730 RTV, 11.1 wt% of trifluoroacetyl-p-decylbenzene (TFADB), and 3.1 wt% of tridodecyl-methylammonium chloride (TDMACl). This carbonate ISE exhibited excellent potentiometric properties (i.e., slope: 26.3 mV/dec; selectivity: $logKT^{pot}_{CO_{2},Cl^-}$= -4.00 and $logKT^{pot}_{TCO_{2},Sal^-}$=1.69); and detection limit for $TCO_2:\;4.0{\times}10^{-4}M$). In addition, the early potentiometric properties of the solid-state sensor with optimized membrane composition were not deteriorated for more than 60 days.

Construction of a Silver(I) Ion-Selective Electrode Using Amine Phenol Ligand as Carrier and the Selective Determination of Silver in Actual Samples (수송체로서 아민페놀을 이용한 은(I)이온-선택 전극의 제조와 실제 샘플에서 은의 선택적 측정)

  • Xu, Wen-Ju;Chai, Ya-Qin;Yuan, Ruo
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.63-69
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    • 2011
  • This work discusses the fabrication, development and potential response behaviors of $Ag^+$ ion-selective electrodes ($Ag^+$-ISE) based on N,N'-bis(2-hydroxybenzyl)-1,3-diaminopropane (L1) and N,N'-bis(2-hydroxybenzyl)-2,2-dimethyl-1,3-diaminopropane (L2) as carriers. The observations indicated that the resulting electrode based on L1 toward $Ag^+$ showed stable near-Nernst slope approaching 58.7 mV/dec and the optimum potential response characteristics in a linear range at least five orders of magnitude with a detection limit of $1.0{\times}10^{-6}M$. The proposed electrode displayed the preferential selectivity to $Ag^+$ against other tested cations. The excellent potential analytical characteristics could lead to the successful applications of silver assay in significant real samples, indicating that the proposed $Ag^+$-ISE showed a significant advancement of measurement capabilities. But for the electrode based on L2, the poor potential response characteristics were observed in total experiment process.