• Journal of Biomedical Engineering Research
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• v.14 no.3
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• pp.227-234
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• 1993

Hemofilter was optimally designed and manufactured using polysulfone hollow fiber mem- brane with surface area of 0.6mE Molecular weight cut-off of the hemofilter was measured with polyethylene glycol and dextran aqueous solutions of various molecular weights and it was ranged from 9,500 to 38,900. Ultrafiltration rates were measured with pure water in a static system and flowing system. The clearance of urea, creatinlne, and vitamine BIB were measured using aqueous solutions.

• Journal of Plant Biology
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• v.36 no.3
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• pp.301-304
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• 1993

Root nodule specific proteins of Alnus hirsuta were examined. SDS-PAGE pattern of the Alnus root nodule was simpler than that of soybean, showing five nodule specific proteins whose molecular weights were 48, 40, 36, 26 and 19 kD, respectively. Among them, 48 kD protein existed most abundantly and were composed of two subunits whose pI value were 4.0 and 4.3, respectively. The 48 kD protein seemed to be a heme containing protein based on reaction with diaminobenzidine. Although 19 kD protein was present in small amount, it was most similar to leghemoglobin in terms of its molecular weight.

• Elastomers and Composites
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• v.50 no.3
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• pp.210-216
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• 2015

Polyurethane modified silicone (PUMS) was synthesized from various molecular weights of polydimethylsiloxane (PDMS 2000, PDMS 6000, PDMS 20000), polypropyleneglycol with molecular weight of 3000 g/mol (PPG 3000) and 2,4-toluenediisocyanate (TDI) under tin catalyst. Their structures were confirmed by the measurement of FT-IR and $^1H-NMR$, and the thermal properties were studied from DSC and TGA. Glass transition temperature of PUMS exhibited exothermic peak at $-63{\sim}-69^{\circ}C$, and residual weight was 19~35% at $800^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1288-1291
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• 1997

4-Allylanisole was polymerized with AlCl3 as a catalyst. The polymerization was carried out in nitroethane at various temperatures with changing the ratio of the initiator to the monomer concentration. The weight averge molecular weights measured by gel permeation chromatography in chloroform with polystyrene standards were between 1,500 and 4,700. 1H NMR spectroscopy showed that the polymerization proceeded through a stepwise aromatic electrophilic substitution reaction along with a minor chain-reaction, resulting in a branched polymer. 4-Chloromethylanisole was also polymerized with AlCl3 in nitroethane through an aromatic electrophilic substitution reaction to give a high molecular weight polymer (Mw=88,000).

• Journal of Plant Biology
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• v.33 no.1
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• pp.59-64
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• 1990

In order to study the effect of GA3 on the phosphorylation of ribosomal proteins during germination in Zea mays, ribosomal proteins were labelled with 32P, extracted, electrophoresed and autoradiographed. There are five phosphorylated ribosomal proteins. One of these is in 40S subunit and has molecular weight of 33,000 daltons. Others are in 60S subunit and have molecular weights of 37,000, 16,000, 15,200 and 13,500, respectively. Phosphorylation of ribosomal proteins was increased maximum 47.7% in shoots of Zea mays treated with GA3.

• BMB Reports
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• v.53 no.7
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• pp.349-356
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• 2020

Mass spectrometry (MS) is an ideal tool for analyzing multiple types of (bio)molecular information simultaneously in complex biological systems. In addition, MS provides structural information on targets, and can easily discriminate between true analytes and background. Therefore, imaging mass spectrometry (IMS) enables not only visualization of tissues to give positional information on targets but also allows for molecular analysis of targets by affording the molecular weights. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS is particularly effective and is generally used for IMS. However, the requirement for an organic matrix raises several limitations that get in the way of accurate and reliable images and hampers imaging of small molecules such as drugs and their metabolites. To overcome these problems, various organic matrix-free LDI IMS systems have been developed, mostly utilizing nanostructured surfaces and inorganic nanoparticles as an alternative to the organic matrix. This minireview highlights and focuses on the progress in organic matrix-free LDI IMS and briefly discusses the use of other IMS techniques such as desorption electrospray ionization, laser ablation electrospray ionization, and secondary ion mass spectrometry.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.48-52
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• 2004

Diffusion/penetration rates of finishing agents are not a major criterion in the design of low molecular weight finishing agents. However, in the case of polymeric finishing agents, high molecular weights result in large hydrodynamic volumes and diffusion/penetration of the finishing agent into the substrate may become a critical factor in the design of textile finishing agents. Thus the effect of the molecular weight of a model compound, polyethylene glycol, on its diffusion through a cellulose membrane or cotton fabric is studied. Diffusion experiments of polyethylene glycol of molecular weight 400, 1000, 2000, 4600, 8000, and 10000 through cellulose membrane or fabric was carried out in a glass U-tube diffusion apparatus and the half penetration times and the penetration coefficients were determined. Both the half penetration times and the penetration coefficients exhibited a significant change between molecular weight 2000 and 2500 as the molecular weight of polyethylene glycol increased, suggesting that there is a critical molecular weight above which diffusion/penetration becomes difficult. Based on this study on a model compound, it is suggested that polymeric textile finishing agents can be expected to exhibit similar behavior.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.63-64
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• 2003

As a part of a research on the development of polymeric textile finishing agents, polymerization of low molecular weight copolymers containing maleic anhydride residues have been studied. In order to obtain low molecular weight poly(maleic anhydride-co-vinyl acetate) copolymers, the feed ratio of the two monomers and the concentrations of initiator and chain transfer agent were varied in the copolymerization. The copolymers were characterized using GPC, NMR, FTIR, DSC, and TGA. Copolymers with molecular weights in the range 2,150 to 6,630 have been prepared and characterized. The hydrolysis of the anhydride groups of the copolymer in water is also discussed.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.324-324
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• 2006

In copolymerization of methyl acrylate (MA) and methyl methacrylate (MMA) with various ratios of MA to MMA and $[CuCl]/[PMDETA]/[PVAc-CCl_{3}]$ catalyst system in bulk at $80^{\circ}C$ via ATRP, several terpolymer with different copolymer composition, were synthesized. The atom transfer radical copolymerization of MA and MMA with macroinitiator, is very sensitive to molecular weight and its distribution. In this work it was possible to calculate the molecular weight of the terpolymers and show that it is close to the experimentally determined number average molecular weight from GPC.

• Textile Coloration and Finishing
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• v.12 no.3
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• pp.166-173
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• 2000

Various kinds of water soluble N,N,N-trimethylchitosan ammonium chloride(TMC) with different molecular weights were synthesized to examine the antimicrobial activity against Methicillin Sensitive Staphylococcus aureus(MSSA) and Methicillin Resistant Staphylococcus aureus(MRSA), which causes serious hospital infection, and to apply them to antimicrobial finishing agents for textiles. Chitosan samples were highly deacetylated with sodium hydroxide solution and degraded with hydrogen peroxide to control the molecular weight. TMC has the antimicrobial activities against MRSA and MSSA. TMC showed an excellent antimicrobial activity below the molecular weight of 70,000, especially at 40,000. The minimum inhibitory concentration (MIC) of TMC with optimum molecular weight against MRSA and MSSA was 250ppm. Because MRSA did not resist TMC in the subculture test of bouillon medium, it was expected that the successive use of TMC against MRSA was possible.