• 제목/요약/키워드: membrane chemistry

검색결과 1,172건 처리시간 0.031초

Concentration/Purification Technologies: Multi-Functionalities of Nanostructures in Biosensing Fields

  • Son, Sang Jun;Min, Junhong
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.87-87
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    • 2013
  • Sample concentration and purification processes are essential in the bio-analytical and pharmaceutical fields because most bio samples or media are extremely sophisticated. To concentrate and purify specific substances, passive membrane type filters have been utilized, which is driven by size or charge differences between target and others. The traditional and representative method to identify nucleic acid sequences in the complex biosample is gel electrophoresis, which has been worked by size and net charge of molecules. The adsorption phenomena have been also utilized to concentrate and purify biomolecules. This adsorption of biomolecule can be controlled under specific salts and surfaces as well as surface area. To utilize the differences of physical properties of molecules or bio-targets such as virus, bacteria, and cells, the nanotechnologies can be introduced in target concentration, purification, and isolation processes. In here, I'd like to briefly survey typical examples of nanobiotechnologies which are introduced in sample treatment. Also I specifically demonstrate two different simple techniques to concentrate and detect bacteria from the samples using multifunctional silica nanotube (SNT).

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천연고분자 기재에 의한 수용성 항고지단백혈증제의 흰쥐 피부투과 특성 (Skin Permeation Characteristics of Antihyperlipoproteinemic Agent using Natural Polymer Bases in Rats)

  • 공승대;황성규;정덕채
    • 한국응용과학기술학회지
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    • 제17권2호
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    • pp.126-131
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    • 2000
  • Transdermal therapeutic system(TTS) is often used as the method of drug dosage into the epidermic skin. Natural polymer were selected as ointment material of TTS. We investigated the permeation of natural polymer ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as oxiniacic acid in vitro. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate. This result suggests a possible use of natural polymer ointment base as TTS of antihyperlipoproteinemic agent.

Role of Cytosolic Phospholipase $A_2$in Cell Injury

  • Kim, Dae-Kyong
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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    • pp.21-22
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    • 2001
  • Phospholipase A$_2$(PLA$_2$) comprise a family of enzymes that hydrolyze the acyl bond at the sn-2 position of phospholipids to generate free fatty acids including arachidonic acid and lysophospholipids. Distinct forms of PLA$_2$are involved in digestion, inflammation, and intercelluar-and intracellular signaling pathways. The released arachidonic acid, which is enriched at the sn-2 position, serves as the precursor for eicosanoids such as prostaglandins and leukotrienes. During oxygenation of arachidonic acid to hydroxy endoperoxide, reactive oxygen radicals are generated. On the other hand, lysophospholipids increase membrane fluidity and can be cytotoxic with its detergent-like action. Thus, the biochemical features of the products of PLA$_2$activity suggest that PLA$_2$may be implicated in many destructive cellular processes.

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Effects of Barbiturates on the Rotational Relaxation Time of 1, 6-Diphenyl-1, 3, 5-hexatriene in Native and Model Membranes

  • Chung, Yong-Za;Shin, Yong-Hee;Choi, Chang-Hwa;Park, Hyung-Sook;Koh, Yeong-Sim;Yun, Il
    • Archives of Pharmacal Research
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    • 제15권4호
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    • pp.298-303
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    • 1992
  • Synaptosomal plasma membrane vesicles (SPMV) were isolated from fresh bovine cerebral cortex. The effects of barbiturates on the rotational relaxation time of 1.6-diphenyl-1, 3, 5-hexatriene (DPH) in intact SPMV and model membranes of total lipids (SPMVTL) and phosphlipids (SPMVPL) extracted from SPMV were examined. Barbiturates decreased the rotational relaxation time of DPH in intact SPMV in a dose-dependent manner. In contrast, they did not affect the rotational relaxation time of DPH in SPMVTL and even dose-dependently increased the rotational relaxation time of DPH in SPMVPL.

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Subcellular Localization of GTP Binding Protein in Stentor coeruleus

  • Park, Phun-Bum;Song, Pill-Soon
    • Journal of Photoscience
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    • 제7권1호
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    • pp.31-34
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    • 2000
  • The heterotrichous ciliate Stentor coeruieus shows a step-up photophobic response to visible light In the previous paper, the existence of GTP-binding proteins was confirmed by using the antisera against the carboxy terminal decapeptide of transducin $\alpha$ subunit. The photoreceptor, stentorin, is localized in the pigment granule. If the immunoreactive G-protein directly interacts with the photoreceptor stentorin, the G-protein expected to be located in the pigment granule rather than plasma membrane. To elucidate the function of the immunoreactive G-protein, the localization of the G-protein in Stentor coeruleus was studied. The results suggest that this G-protein is located in the myoneme involved in the contraction and extension of the cell rather than in the pigment granule.

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고분자 전해질형 연료전지 자동차의 급기 시스템의 동적 모델링 및 분석 (Dyamic Modeling and Analysis of Air Supply System for Vehicular PEM Fuel Cell)

  • 장현탁
    • 한국수소및신에너지학회논문집
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    • 제15권3호
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    • pp.175-186
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    • 2004
  • In this paper, we developed the dynamic model of a fuel cell system suitable for controller design and system operation. The transient phenomena captured in the model include the flow characteristics and inertia dynamics of the compressor, the intake manifold filling dynamics, oxygen partial pressures and membrane humidity on the fuel cell voltage. In the simulations, we paid attention to the transient behavior of stack voltage and compressor pressure, stoichiometric ratio. Simulation results are presented to demonstrate the model capability. For load current following, stack voltage dynamic characteristics are plotted to understand the Electro-chemistry involved with the fuel cell system. Compressor pressure and stoichiometric ratio are strongly coupled, and independent parameters may interfere with each other, dynamic response, undershoot and overshoot.

Ethanol Production from Lignocellulosic Biomass by Simultaneous Saccharification and Fermentation Employing the Reuse of Yeast and Enzyme

  • KIM, JUN-SUK;KYUNG-KEUN OH;SEUNG-WOOK KIM;YONG-SEOB JEONG;SUK-IN HONG
    • Journal of Microbiology and Biotechnology
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    • 제9권3호
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    • pp.297-302
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    • 1999
  • Simultaneous saccharification and fermentation (SSF) experiments were carried out with a lignocellulosic biomass. The effects of temperature on enzymatic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 g/g, which was increased by 67% or higher over the saccharification at 42℃. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate, and separation coefficient, related to the SSF combined with membrane system (semi-batch system). When the fermentation was operated in a semi-batch mode, the efficiency of the enzymes and yeast lasted three times longer than in a batch mode.

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A Dipstick-Type Electrochemical Immunosensor for The Detection of The Organophosphorus Insecticide Fenthion

  • Cho, Young-Ae;Cha, Geun-Sig;Lee, Yong-Tae;Lee, Hye-Sung
    • Food Science and Biotechnology
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    • 제14권6호
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    • pp.743-746
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    • 2005
  • A dipstick-type immunochemical biosensor for the detection of the organophosphorus insecticide fenthion was developed using a screen-printed electrode system as an amperometric transducer with polyclonal antibodies against fenthion as a bioreceptor. The assay of the biosensor involved competition between the pesticide in the sample and pesticide-glucose oxidase conjugate for binding to the antibody immobilized on the membrane. This was followed by measurement of the activity of the bound enzyme by the supply of the enzyme substrate (glucose) and amperometric determination of the enzyme reaction product ($H_2O_2$). The activity of the bound enzyme was inversely proportional to the concentration of pesticide. The optimized sensor system showed a linear response against the logarithm of the pesticide concentration ranging from $10^{-2}$ to $10^3\;{\mu}g/L$.

Isolation and Identification of a Pentachloronitrobenzene(PCNB) Degrading Bacterium Alcaligenes xylosoxidans PCNB-2 from Agricultural Soil

  • Shin, Sung-Kyu;Kim, Jang-Eok;Kwon, Gi-Seok;Kwon, Jin-Wook;Oh, Eun-Taex;So, Jae-Seong;Koh, Sung-Cheol
    • Journal of Microbiology
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    • 제41권2호
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    • pp.165-168
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    • 2003
  • We report a new PCNB-degrading strain (PCNB-2) that is able to utilize and grow on PCNB (100 ppm) as a sole carbon source. This strain was identified as Alcaligenes xylosoxidans based upon 16S rDNA sequence analysis, API 20 NE tests and cell membrane lipid analysis. The new PCNB degrader Alcaligenes xylosoxidans PCNB-2 could find use in bioremediation of PCNB, which is environmentally persistent.

Phospholipid Analysis by Nanoflow Liquid Chromatography-Tandem Mass Spectrometry

  • Moon, Myeong Hee
    • Mass Spectrometry Letters
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    • 제5권1호
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    • pp.1-11
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    • 2014
  • Lipids play important roles in biological systems; they store energy, play a structural role in the cell membrane, and are involved in cell growth, signal transduction, and apoptosis. Phospholipids (PLs) in particular have received attention in the medical and lipidomics research fields because of their involvement in human diseases such as diabetes, obesity, atherosclerosis, and many cancers associated with lipid metabolic disorders. Here I review experimental strategies for PL analysis based on nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MSn). In particular, discussed are lipid extraction methods, nanoflow LC separation of PLs, effect of ionization modifiers on the ESI of PLs, influence of chain lengths and unsaturation degree of acyl chains of PLs on MS intensity, structural determination of the molecular structure of PLs and their oxidized products, and quantitative profiling of PLs from biological samples such as tissue, urine, and plasma in relation to cancer and coronary artery disease.