• Title/Summary/Keyword: Isoelectric point

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A study of estimation and removal of baseline drift for the automated diagnosis of electrocardiogram (심전도 자동 진단을 위한 기저선 동요 평가 및 제거에 관한 연구)

  • 권혁제;이명호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.7
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    • pp.99-106
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    • 1996
  • Estimation and removal procedures for baseline drift have been developed using linear, cubic spline, and bilineared transformed high pass filter. Linear and cubic spline interpolation with the PQ and TP segmens, which are considered to be isoelectric, as fiducial points ahve been estimated respectively. For a quantitative validation of the estimation procedure, 4 ECGs with arfificial baseline drift were constructed and analyzed by mean square error calculations and amplitude histograms. Also real ECGs were analyzed in a test set of the CSE data set 3 and set 4. Baseline drift detecton rule were designed and new method for the decision of fiducial point were constructed to avoid distorting as the case of premature ventricular or atrial contraction. From these comparison, proposed cubic spline method with PQ and TP segment (CS_PQ & TP) emerged as the most efficient method.

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Characteristics of Zeta Potential Distribution in Silica Particles

  • Kim, Jin-Keun;Lawler, Desmond F.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.7
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    • pp.1083-1089
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    • 2005
  • Most experimental studies available in the literature on filtration are based on observed average zeta potential of particles (usually 10 measurements). However, analyses of data using the average zeta potential alone can lead to misleading and erroneous conclusions about the attachment behavior because of the variation of particle zeta potentials and the heterogeneous distribution of the collector surface charge. To study characteristics of zeta potential, zeta potential distributions (ZPDs) of silica particles under 9 different chemical conditions were investigated. Contrary to many researchers’ assumptions, most of the ZPDs of silica particles were broad. The solids concentration removal was better near the isoelectric point (IEP) as many researchers have noticed, thus proper destabilization of particles is very important to achieve better particle removal in particle separation processes. While, the mean zeta potential of silica particles at a given coagulant dose was a function of particle concentration; the amount of needed coagulant for particle destabilization was proportional to the total surface charge area of particles in the suspension.

Dispersant-Binder Interactions in Aqueous Silicon Nitride Suspensions

  • Paik, Ungyu
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06b
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    • pp.129-153
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    • 1996
  • In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder on the surface of particles was studied to identify the effect of these additives on ceramic powder processing. Polymethacrylic acid (PMAA) and polyvinyl alcohol (PVA) were used as dispersant and binder, respectively. the adsorption isotherms of PMAA and PVA for the silicon nitride suspension were determined, while the adsorption of PMAA was differentiated in the mixed additive system by ultraviolet spectroscopy. These experiments were done in order to investigate the effect of these organic additives on the physicochemical properties of silicon nitride suspensions. The electrokinetic behavior of silicon nitride was subsequently measured by electrokinetic sonic amplitude (ESA). As PMAA adsorbed onto silicon nitride, the isoelectric point (pHicp) shifted from pH=6.7 to acidic pH, depending on the surface coverage of PMAA. However, adsorption of PVA did not change the pHicp of suspensions, but did decrease the surface potential of silicon nitride moderately. The rheological behavior of silicon nitride suspensions was measured to assess the stability of particles in aqueous media, and was correlated with the electrokinetic behavior and adsorption isotherm data for silicon nitride.

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On the Micellization of ${\alpha}$-Amino Capric Acid (${\alpha}$-아미노카프르산의 Micelle 형성을 위한 한계농도에 관하여)

  • Ryu, Ji-Yong;Chang, Sei-Hun
    • Journal of the Korean Chemical Society
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    • v.10 no.4
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    • pp.161-165
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    • 1966
  • The critical concentrations of ${\alpha}$-amino capric acid for micelle formation have been determined by the surface tension measurements in both acidic and alkaline solutions, and also by the dye titration using Rhodamine B in alkaline solutions. The critical micelle concentrations obtained by the two methods show the good agreements within experimental errors. Since ${\alpha}$-amino acid is an ampholyte, it may aggregate to form the micelles in both more acidic and basic media than its isoelectric point. It is found that the basic media are rather preferable for the micelle formation than the acidic media. The effect of gegen ions upon the critical concentration for micelle formation in alkaline media is similar to that expected from the salt effect on the CMC (Critical Micelle Concentration).

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Properties of the Extracellular Proteins Produced by Bacillus sp. WY-60 (Bacillus sp. WY-60이 생산한 균체외 단백질의 특성)

  • Kwon, Oh-Jin;Park, Shin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.6
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    • pp.807-810
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    • 1993
  • Extracellular proteins of Bacillus sp. WY-60 were obtained, and then the properties of the isolated proteins were characterized. The proteins were composed of two kinds of protein in size. The molecular weight of the major protein was around 21,000 according to the gel filtration chromatography and SDS-polyacryamide gel electrophoresis. The amino acid composition showed that glutamic acid was a major amino acid with the concentration of 26.16mg/g. The isoelectric point of the proteins was about pH 7.5.

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The Study on Protein Separations Using Ultrafiltration Membranes (한외여과막을 이용한 단백질 분리에 관한 연구)

  • 최원영;임균택이규현박돈희
    • KSBB Journal
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    • v.6 no.2
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    • pp.215-222
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    • 1991
  • The experimental investigations about ultrafiltration(UF) of bovine serum albumin(BSA) solutions were conducted with a batch stirred cell. This study was investigated on the permeate flux. The experiment was carried out at pH 4.8. Protein concentrations were measured spectrophotometrically. For very dilute samples, a Lowry method was used. In the ultrafiltration of dilute BSA solutions, the permeate flux according to working time was decreased smoothly and at isoelectric point, concentration polarization of BSA solution was ignored at limited working pressures by magnetic stirring.

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Flavobacterium meningosepticum 기원 Peroxidase의 정제 및 특성

  • 최양문;조홍연;양한철
    • Microbiology and Biotechnology Letters
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    • v.24 no.5
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    • pp.585-590
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    • 1996
  • Peroxidase was purified to homogeneity from cell free extract of Flavobacterium meningosepticum. The molecular weight of the enzyme estimated by gel filtration column chromatography was 220, 000. A identical subunit (54, 000) was detected on SDS-PAGE of the enzyme. From these results, the enzyme was supposed to have four identical subunits. On the basis of the visible absorption spectra of the purified enzyme, the enzyme was a typical hemoprotein. The isoelectric point of the enzyme was 4.1. On using N-ethyl-N-(2-hydroxy-3-sulfopropyl)-m- toluidine (Toos) as a hydrogen donor, the enzyme showed optimum activity at the pH 5.5 and 50$\circ$C. The enzyme activity was inhibited by carbonyl reagent and Hg$^{2+}$ .

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Molecular Characterization of Apolipophorin-III in the Fall Webworm, Hyphantria cunea Drury

  • Kim, Hong-Ja;Lee, Sang-Dae;Seo, Sook-Jae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.3 no.2
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    • pp.163-168
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    • 2001
  • We isolated and sequenced a cDNA clone corresponding to apolipophorin-III (apoLp-III) from the fall webworm, Hyphantria cunea. The cDNA for apoLp-III codes fer a 187-residue protein (561 bp) with a predicted molecular mass of 20 kDa. The calculated isoelectric point is 8.76. Multiple alignment analysis of the amino acid sequence revealed that H. cunea apoLp-III is most similar to that of Spodoptera litura (71.5% identity), followed by that of Manduca sexta (69.7% identity). They share five amphipathic $\alpha$-helices that are proposed to play a critical role in the binding of apoLp-III to lipophorin.

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Cloning and Characterization of 6-Phosphogluconolactonase Gene in Silkworm Bombyx mori

  • Yang, HuaJun;Chen, KePing;Yao, Qin;Guo, ZhongJian
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.2
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    • pp.69-74
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    • 2007
  • As the genome of B. mori is available in GenBank and the EST database of B. mori is expanding, identification of novel genes of B. mori was conceivable by datamining techniques and bioinformatics tools. In this study, we used the in silico cloning method to get the 6-Phosphogluconolactonase (6PGL) gene of B. mori and analysed with bioinformatics tools. The result was confirmed by RT-PCR and prokaryotic expression. The 6PGL cDNA comtains a 702 bp ORF. The deduced protein has 233 amino acid residues, with the predicted molecular weight of 25946. 72 Da, isoelectric point of 5.41, and contains conserved NagB domains. This gene has been registered in GenBank under the accession number EF198104.

Changes of Emulsifying and Foaming Properties of Soy Protein with an Calcium , HCI and Microbial IJ-3 Strain Enzyme

  • Park, Yang-Won;Kim, Young-Jeon
    • Preventive Nutrition and Food Science
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    • v.1 no.1
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    • pp.53-58
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    • 1996
  • The characterstics of the soy protein curd(eczyme-, HCI- and Ca-surd) were shown by scanning electron micrographs and gel electrophoreis. The emulsion stability of enzyme-curd showed high value in the range of pH 2~10and wide range of temperature(20~8$0^{\circ}C$). While at the isoelectric point(pH5.0), the emulsion stability of the HCI-and Ca-curd was decreased remarkably, and the emulsion stability of temperature was reduced quickly to the 60% and 40% at the 4$0^{\circ}C$. The foam stability of enzyme-curd was slightly higher than that HCI-and CA-curd in all ranges of pH and temperature. The feature of SEM of enzyme-cured produced degradation products faster than that of the HCI- and Ca-curd.

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