1,720,986 research outputs found
Effective extraction of oligomeric proanthocyanidin (OPC) from wild grape seeds
No full textThe Oligomeric proanthocyanidin (OPC) in green and black tea, grape seeds, grapes and wine has raised much attention but that OPC in wild grape seed remains to be intensively investigated. This study investigated the total OPC contents and total antioxidant activity of wild grape seeds and developed an efficient extraction process with various temperatures, solvent compositions and times. Also, a chromatography column packed with the Dia-ion HP-20 resin was used for further purification of the OPC. The total OPC contents were determined with the Folin-Ciocalteu reagent, and the antioxidant activity using total antioxidant potential (TAP) and 1,1-diphenyl-2picrylhydrazyl (DPPH). The yield of final purified OPC was 1.78 (+)-catechin equivalent (CE) g/100 g, with IC50 activities of TAP and DPPH of 31.60 and 15.70 mug/mL. These activities of the final purified OPC were about two times higher than that of the BHA used as a reference sample
Novel synthesis of 1 and 3-dimensionally nanostructured ionic liquids/aluminum hydroxide composite via supramolecular assembly: Effect of water on the formation of nanostructure
No full text
Selective extraction of acetic acid from the fermentation broth produced by Mannheimia succiniciproducens
No full textAcetic acid is by-product from fermentation processes for producing succinic acid using Mannheimia succiniciproducens. To obtain pure succinic acid from the final fermentation broth, acetic acid was selectively removed based on the different extractability of succinic acid and acetic acid with pH using tri-n-octylamine (TOA) as extractant. When successive batch extractions were performed using 0.25 mol TOA kg(-1) dissolved in 1-octanol at pH 5, the mol ratio of succinic acid to acetic acid before extraction was 4.9 and the final ratio after the fourth batch was 9.4.The authors are grateful to the Center for Advanced
Bioseparation Technology Research (BSEP, KOSEF)
for the funding
Development of a fully integrated microfluidic system for sensing infectious viral disease
No full textAn active micromixer system utilizing the magnetic force was developed and examined for its ability to facilitate the mixing of more than two fluid flows. The mixing performance of the active micromixer was evaluated in aqueous-aqueous systems including dyes for visual observation. A complete analytical microfluidic system was developed by integrating various functional modules into a single chip, thus allowing cell lysis, sample preparation, purification of intracellular molecules, and subsequent analysis. Upon loading the cell samples and lysis solution into the mixing chamber, the integrated microfluidic device allows efficient cell disruption by rotation of a micromagnetic disk and control of mixing time using the Teflon-coated hydrophobic film as a microvalve. This inflow is followed by separating the cell debris and contaminated proteins from the cell lysate sample using the acrylamide (AAm)-functionalized SPE. The inflow of partially purified cell lysate sample containing the gold binding polypeptide (GBP)-fusion protein was bound onto the gold micropatterns by means of its metal binding affinity. The GBP-fusion method allows immobilization of proteins in bioactive forms onto the gold surface without surface modification suitable for studying antigen-antibody interaction. It was used for the detection of severe acute respiratory syndrome (SARS), an infectious viral disease, as an example case.This work was supported by the Basic Research Program of
the Korea Science & Engineering Foundation (R01-2006-000-
11175-0 for WHH and TJP) and by the IT Leading R&D Support
Project from the Ministry of Knowledge Economy through
IITA (SYL and TJP). Further supports by the LG Chem Chair Professorship and the KOSEF through the Center for Ultramicrochemical
Process Sytems (SYL) are appreciated. We also
thank K.-B. Lee (Korca Basic Science Institute, Korea) for his
kind advice for electrochemical analysis
Kinetics and mechanism of the interfacial mass-transfer of succinic acid in a microporous membrane-based cell
No full textSCANNING TUNNELING MICROSCOPE WITH NOVEL COARSE SAMPLE POSITIONING TECHNIQUE
No full textWe have constructed a scanning tunneling microscope with coarse positioning device which enables adjustment of the sample to tip distance into operating range of z-piezo element without stretching for each step of sample approach. This new convenient technique is achieved by monitoring sample current during coarse sample approach. The sample to tip distance of several thousand angstroms could be detected directly on oscilloscope. It is considered that sample current is generated by field emission mode of tip operation or field ionization of air molecules due to a potential induced by sawtooth voltage used for driving inertial piezotranslator. In addition, the topographic images of clusters and ultrathin films of carbon on cleaved graphite will be presented.This work was supported in part by the Basic science research institute program of ministry of education, and in part by KOSEF
Effective purification of succinic acid from fermentation broth produced by Mannheimia succiniciproducens
No full textThe present study deals with the development of purification and separation processes required to produce the highly purified succinic acid from the fermentation broth produced by recombinant microorganism, Mannheimia succiniciproducens. The newly developed process consists of the pretreatment process such as reactive extraction and vacuum distillation step and the crystallization process for the highly purified succinic acid production. By-produced acids were effectively removed by the reactive extraction as a primary separation. In addition, the crystallization was applied without adding any salts to produce highly purified succinic acid. The purified succinic acid, with 99.8% purity and 73.1% yield rate was obtained through this newly developed purification process. (c) 2006 Elsevier Ltd. All rights reserved.This work was supported by the Genome-based Integrated
Bioprocess Project of the Ministry of Science and Technology.
Further supports by Brain Korea 21 (BK21)
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