• 제목/요약/키워드: affinity matrix

검색결과 96건 처리시간 0.024초

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

  • 황채림;라즈쿠마 파텔
    • 멤브레인
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    • 제31권1호
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    • pp.1-15
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    • 2021
  • 이온성 액체 기반 혼합 멤브레인(MMM)은 이산화탄소 분리 매체로써 다양한 종류의 이온성 액체와 무기성 필러 폴리머에 의해 만들어진다. 이온성 액체와 무기성 필러의 강한 상호작용은 이산화탄소의 금속 유기체의 프레임워크 내 친화력, 선택성, 흡착성을 높여 분리성능을 향상시킨다. 또, 이온성 액체에 의해 혼합 매트릭스 멤브레인의 구조적 특성이 조절되어 이산화탄소 투과성과 선택성을 향상시킨다. 이 리뷰에서는 이산화탄소 분리를 위한 고분자 막에서의 이온성 액체(IL)와 금속 유기체 프레임워크(MOF)의 다양한 조합에 대한 연구가 논의될 것이다.

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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    • 제28권4호
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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.

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

  • 이연희
    • 미생물학회지
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    • 제27권2호
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    • pp.117-123
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    • 1989
  • Radioactive NBZ arginyl diazomethane으로 액포를 표지 한 뒤에ㅣ 액포내의 단백질과 세포막 겉에 존재하는 단백질을 각각 저농도 완충용액과 높은 농도의 염용액으로 제거시켰다. 액포막 단백질을 Triton X-100으로 녹인 후, molecular sieve column chromatography와 ion exchange column chromatography를 사용하여 anginine transporter를 분리하였다.

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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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    • 제24권2호
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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.

준정부호 스펙트럼의 군집화 (Semidefinite Spectral Clustering)

  • 김재환;최승진
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (A)
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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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    • 제5권5호
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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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    • 제37권2호
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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.

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

  • 김수용;손명찬;양진국
    • 한국건설관리학회논문집
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    • 제14권3호
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    • pp.157-166
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    • 2013
  • BTL(Build-Transfer-Lease) 사업의 목적은 종래 BTO(Build-Transfer-Operate) 방식과는 달리 학교, 사회복지시설 등 최종 이용자로부터 이용료를 부과할 수 없는 공공시설에 대하여 민간자금을 유치함으로써 정부의 재정부족을 해결하고 사회기반시설의 조기 확충을 위한 방안으로 도입되었다. 하지만 BTL 사업은 그 진행과정에서 다양한 문제점을 발생시키고 있으며, 이를 개선할 수 있는 실질적인 접근이 요구된다. 이에 본 연구에서는 국내의 BTL사업의 문제점에 대한 연구 자료와 국내보다 앞서 BTL 사업을 활용하고 있는 국외 자료를 분석하여 문제 영역을 도출하였다. 그리고 이를 체계적으로 관리하기 위해 친화도 기법, 매트릭스 비교분석, AHP 기법을 활용하여 중요도를 분석하였다. 분석된 결과는 BTL 사업의 실질적 문제 영역 및 중요도 제시를 통하여 관리 기준을 제공할 것으로 기대된다.

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

  • Jeong, Seung-Young
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2004년도 학술논문집
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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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119구급대 주들것의 문제점과 그 개선방안에 관한 연구 (A Study on the Problems and Improvement Solutions for the Ambulance Stretcher)

  • 함승희;송우승;윤명오
    • 한국화재소방학회논문지
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    • 제28권3호
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    • pp.72-79
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    • 2014
  • 본 연구는 119구급대에서 사용하는 주들것의 문제점을 확인하고 그 개선방안을 도출하는 것을 목적으로 한다. 주들것의 문제점 도출을 위하여 문헌분석, 설문조사법을 사용하였고, 개선지표의 도출을 위해 KJ법(가와기타 지로법, 친화도법), 그래프기법, 우선순위 행렬법을 활용하였다. 주들것의 문제점은 현재 구급자동차의 부품으로서 인식되는 점, 성능확인 기준이 미비한 점, 조작 중 구급대원 부상 및 환자사고가 발생하는 점으로 요약할 수 있었으며, 이를 개선할 수 있는 개선지표로는 조작편리성, 고성능, 다기능, 주행성, 내구성, 경량화가 도출되었다. 이 지표에 대한 상호연관성 분석 및 우선순위행렬법 적용 결과는 조작편리성 ${\rightarrow}$ 다기능 ${\rightarrow}$ 주행성 ${\rightarrow}$ 고성능 ${\rightarrow}$ 내구성 경량화 순으로 나타났다.