• Title/Summary/Keyword: Affinity matrix

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Recent Advances on Ionic Liquid based Mixed Matrix Membrane for CO2 Separation (CO2 분리를 위한 이온성 액체 기반 혼합 매트릭스 멤브레인의 최근 발전)

  • Wang, Chaerim;Patel, Rajkumar
    • Membrane Journal
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    • v.31 no.1
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    • pp.1-15
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    • 2021
  • The membrane-based CO2 capture is a fast-growing branch in gas separating field. Ionic liquid assisted mixed matrix membrane (MMM), which consists of organic fillers with dispersed ionic liquid, shows high potentiality as a candidate for CO2 separation medium. In MMM, various kinds of ionic liquid and inorganic filler are incorporated into polymer to enhance gas separating performance. Especially, the strong interaction between ionic liquid and organic filler gives huge influence on enhancing the separating performance by increasing affinity, selectivity and adsorption of CO2 into the framework. Also the mechanical properties of metal organic framework are positively tuned by input of ionic liquid to improve CO2 permeability and selectivity. In this review, study of various combinations of ionic liquid and metal organic framework (MOF) in the polymeric membrane for carbon dioxide separation is discussed.

Role of TGF-β1/SMADs signalling pathway in resveratrol-induced reduction of extracellular matrix deposition by dexamethasone-treated human trabecular meshwork cells

  • Amy Suzana Abu Bakar;Norhafiza Razali;Renu Agarwal;Igor Iezhitsa;Maxim A. Perfilev;Pavel M. Vassiliev
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.4
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    • pp.345-359
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    • 2024
  • Deposition of extracellular matrix (ECM) in the trabecular meshwork (TM) increases aqueous humour outflow resistance leading to elevation of intraocular pressure (IOP) in primary open-angle glaucoma, which remains the only modifiable risk factor. Resveratrol has been shown to counteract the steroid-induced increase in IOP and increase the TM expression of ECM proteolytic enzymes; however, its effects on the deposition of ECM components by TM and its associated pathways, such as TGF-β-SMAD signalling remain uncertain. This study, therefore, explored the effects of trans-resveratrol on the expression of ECM components, SMAD signalling molecules, plasminogen activator inhibitor-1 and tissue plasminogen activator in dexamethasone-treated human TM cells (HTMCs). We also studied the nature of molecular interaction of trans-resveratrol with SMAD4 domains using ensemble docking. Treatment of HTMCs with 12.5 µM trans-resveratrol downregulated the dexamethasone-induced increase in collagen, fibronectin and α-smooth muscle actin at gene and protein levels through downregulation of TGF-β1, SMAD4, and upregulation of SMAD7. Downregulation of TGF-β1 signalling by trans-resveratrol could be attributed to its effect on the transcriptional activity due to high affinity for the MH2 domain of SMAD4. These effects may contribute to resveratrol's IOP-lowering properties by reducing ECM deposition and enhancing aqueous humour outflow in the TM.

Purification of the Vacuolar Arginine Transporter from Neurospora crassa (Neurospora crassa로부터 arginine transporter의 순수분리)

  • ;Weiss, R. L.
    • Korean Journal of Microbiology
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    • v.27 no.2
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    • pp.117-123
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    • 1989
  • Radioactive N-$\alpha$-p-nitrobenzoxycarbonyl (NBZ)-L-[2,$3-^{3}$H] arginyl diazomethane was used as an affinity label for the vacuolar arginine transporter in Neurospora crassa. Vacuolar matrix proteins were removed by fracturing the membranes with freeze-thaw method in dry ice/ethanol bath. Vacuolar membrane proteins were then wasged with 500mM NaCl to remove ionically bound derivatives and peripheral membrane proteins from vacuolar membranes. After dissolved in 1% Titon X-100, dissolved vacuolar memvrane proteins were separated with molecular sieve column chromatography, anion and cation exchange chromatographies. The arginine transporter was purified giving the purification factor of 1136.

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Isolation of the Arabidopsis Phosphoproteome Using a Biotin-tagging Approach

  • Kwon, Sun Jae;Choi, Eun Young;Seo, Jong Bok;Park, Ohkmae K.
    • Molecules and Cells
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    • v.24 no.2
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    • pp.268-275
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    • 2007
  • Protein phosphorylation plays a key role in signal transduction in cells. Since phosphoproteins are present in low abundance, enrichment methods are required for their purification and analysis. Chemical derivatization strategies have been devised for enriching phosphoproteins and phosphopeptides. In this report, we employed a strategy that replaces the phosphate moieties on serine and threonine residues with a biotin-containing tag via a series of chemical reactions. Ribulose 1,5-bisphosphate carboxylase/oxygenase (RUBISCO)-depleted protein extracts prepared from Arabidopsis seedlings were chemically modified for 'biotin-tagging'. The biotinylated (previously phosphorylated) proteins were then selectively isolated by avidin-biotin affinity chromatography, followed by two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). This led to the identification of 31 protein spots, representing 18 different proteins, which are implicated in a variety of cellular processes. Despite its current technical limitations, with further improvements in tools and techniques this strategy may be developed into a useful approach.

Semidefinite Spectral Clustering (준정부호 스펙트럼의 군집화)

  • Kim, Jae-Hwan;Choi, Seung-Jin
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07a
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    • pp.892-894
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    • 2005
  • Graph partitioning provides an important tool for data clustering, but is an NP-hard combinatorial optimization problem. Spectral clustering where the clustering is performed by the eigen-decomposition of an affinity matrix [1,2]. This is a popular way of solving the graph partitioning problem. On the other hand, semidefinite relaxation, is an alternative way of relaxing combinatorial optimization. issuing to a convex optimization[4]. In this paper we present a semidefinite programming (SDP) approach to graph equi-partitioning for clustering and then we use eigen-decomposition to obtain an optimal partition set. Therefore, the method is referred to as semidefinite spectral clustering (SSC). Numerical experiments with several artificial and real data sets, demonstrate the useful behavior of our SSC. compared to existing spectral clustering methods.

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Some Model Solute Affinity for a Tactic p-HEMA Membranes by K$_D$ Measurement

  • Lee, Eun-Hee;Jeon, Sang-Il;Jhon, Mu-Shik
    • Bulletin of the Korean Chemical Society
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    • v.5 no.5
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    • pp.175-178
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    • 1984
  • Two series of membranes have been prepared by postcrosslinking highly syndiotactic and isotactic poly (2-hydroxyethyl methacrylate), P(HEMA). The crosslinker used was hexamethylene diisocyante (HMDIC). The distribution coefficients (K$_{D2}$) of the model solutes such as urea (and thiourea), their derivatives, homologous alcohol series and amide sreies in water-swollen tactic P(HEMA) membranes at $25^{\circ}C$ were mesaured. In addition, the concentration effects of acetamide and butyramid were also measured. On the basis of hydrophobic interaction and the structural factors of tactic P(HEMA) membranes, the hydrophobic adsorption of the solutes in the polymer matrix were discussed. The results showed that the more hydrphobic the solute is, the higher the $K_{D2}$ value is. And the polymer conformation also affects the distribution of solvents.

Comprehensive proteome analysis using quantitative proteomic technologies

  • Kamal, Abu Hena Mostafa;Choi, Jong-Soon;Cho, Yong-Gu;Kim, Hong-Sig;Song, Beom-Heon;Lee, Chul-Won;Woo, Sun-Hee
    • Journal of Plant Biotechnology
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    • v.37 no.2
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    • pp.196-204
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    • 2010
  • With the completion of genome sequencing of several organisms, attention has been focused to determine the function and functional network of proteins by proteome analysis. The recent techniques of proteomics have been advanced quickly so that the high-throughput and systematic analyses of cellular proteins are enabled in combination with bioinformatics tools. Furthermore, the development of proteomic techniques helps to elucidate the functions of proteins under stress or diseased condition, resulting in the discovery of biomarkers responsible for the biological stimuli. Ultimate goal of proteomics orients toward the entire proteome of life, subcellular localization, biochemical activities, and their regulation. Comprehensive analysis strategies of proteomics can be classified as three categories: (i) protein separation by 2-dimensional gel electrophoresis (2-DE) or liquid chromatography (LC), (ii) protein identification by either Edman sequencing or mass spectrometry (MS), and (iii) quanitation of proteome. Currently MS-based proteomics turns shiftly from qualitative proteome analysis by 2-DE or 2D-LC coupled with off-line matrix assisted laser desorption ionization (MALDI) and on-line electrospray ionization (ESI) MS, respectively, to quantitative proteome analysis. Some new techniques which include top-down mass spectrometry and tandem affinity purification have emerged. The in vitro quantitative proteomic techniques include differential gel electrophoresis with fluorescence dyes, protein-labeling tagging with isotope-coded affinity tag, and peptide-labeling tagging with isobaric tags for relative and absolute quantitation. In addition, stable isotope labeled amino acid can be in vivo labeled into live culture cells through metabolic incorporation. MS-based proteomics extends to detect the phosphopeptide mapping of biologically crucial protein known as one of post-translational modification. These complementary proteomic techniques contribute to not only the understanding of basic biological function but also the application to the applied sciences for industry.

An Extraction and Analysis of Problem Areas for BTL Projects from the Practical Perspective (실무적 관점에서의 BTL사업 문제영역 도출 및 분석)

  • Kim, Soo-Yong;Son, Myung-Chan;Yang, Jin-Kook
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.3
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    • pp.157-166
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    • 2013
  • Unlike conventional BTO(Build-Transfer-Operate) projects, this BTL project aims at fixing the financial deficiencies of the government and expanding infrastructure through private capital. It allows the government to attract private capital for the construction of public facilities such as schools and social welfare agencies for whom private users don't need to pay, thereby bolstering national finance. BTL projects are causing a variety problems in progress. Therefore, we are required a practical approach to can improving a variety problems. In this study, we were derive the problem areas as follow. First, research data on the problem of domestic BTL projects, Second, high-performing foreign data analysis than domestic. And, we were analyzed to systematic management method for problem areas by using affinity techniques, matrix comparison analysis, AHP technique. Results of this study are expected provide management standards through real problem areas and the analyzing of relatively importance.

Glass Dissolution Rates From MCC-1 and Flow-Through Tests

  • Jeong, Seung-Young
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.257-258
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    • 2004
  • The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

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A Study on the Problems and Improvement Solutions for the Ambulance Stretcher (119구급대 주들것의 문제점과 그 개선방안에 관한 연구)

  • Ham, Seung Hee;Song, Woo Seung;Yoon, Myung O
    • Fire Science and Engineering
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    • v.28 no.3
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    • pp.72-79
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    • 2014
  • The purpose of this study is to draw the improvement plan through the analysis of problems of main stretchers that are being used by the 119 EMS. In order to find out the problems, we used the literature review and analysis, survey questionnaire and we also made full use of KJ method (Kawakita Jiro method, affinity diagram), graph method, and priority matrix method to produce the improvement indicators. The problems of main stretchers are summarized as follows. they are being recognized as part of the emergency vehicle, they have the imperfection of performance verification criteria, and they cause the injuries of paramedics and patients accidents in operation. The indicators such as the ease of operation, the high performance, the multi-function, the driving performance, the durability and the lightweight, was produced to improve the problems. The results of the interconnection analysis and the applying priority matrix method on the indicators are the ease of operation ${\rightarrow}$ the multi-function ${\rightarrow}$ the driving performance ${\rightarrow}$ the high performance ${\rightarrow}$ the durability and the lightweight in order of importance.