• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.171-177
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• 2007

Polymer-based electrically conductive pastes have been used to make the conductive paths between voltage sources and devices. The pastes used for these applications consist of two main components: a polymer binder and a conductive filler. Having both low viscosity and good metal-encapsulating properties, cellulose acetate butyrate (CAB) was regarded to be a good candidate as a binder for the conductive paste. We have prepared a formulation for a novel conductive paste based on CAB. Preliminary studies showed that this conductive paste revealed stable conductivity, together with uniform coating and flexibility.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.9-12
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• 2005

Molecular characteristics and rheological properties of cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP) and nitrocellulose (GC-519) which are being widely used as propellants were investigated. Their weight-average molecular weight (Mw) and number-average molecular weight (Mn) were estimated via Gel Permeartion Chromatograpy (GPC). Cellulose derivatices were mixed with di-n-propyl adipate (DNPA) which acted as plasticizer in acetone, and then rheological properties of the mixture of cellulose derivatives and this plasticizer in acetone were investigated at $0^{\circ}C$ by rheometer.

• Membrane Journal
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• v.24 no.2
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• pp.167-175
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• 2014

For selectively permeable membrane based on cellulose acetate butyrate (CAB) and polyethyleneimine (PEI) with water vapor transportability and DMMP protective performance, we intended to improve protective performance of the membrane against CEES using several additives. Results showed that CAB/PEI membranes possessed performance with good water vapor permeation (${\geq}1,800g/m^2/day$) and enhanced protective capability against CEES contamination ($7.1{\sim}11.5{\mu}g/cm^2{\cdot}day$). Of these membranes, the membrane containing $Ag^+$ ion and ionic exchange resin showed the best protective performance. And, we identified that the CAB/PEI membranes show excellent protection against aerosols with various particle sizes ($0.005{\sim}3{\mu}m$) simulating biological agents.

• Journal of Life Science
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• v.22 no.11
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• pp.1571-1586
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• 2012

On earth, there are about 5,400 kinds of mammals, of which about 1,000 kinds are herbivores. Among herbivores, about 250 kinds are known to be ruminants. As for cattle and sheep, which are ruminants, fermentation takes places mainly in their rumen; in contrast, for pigs and men, which are non-ruminants, fermentation takes place mainly in their caecum, colon, and rectum. As for the kind and dominance of rumen microorganisms, Bacteroidetes account for 51% and Firmicutes for 43%. As for the dominance of the large intestine microorganisms in men, Firmicutes account for 65% and Bacteroidetes for 25%. Cell wall components are decomposed by microorganisms, and short chain fatty acids (SCFAs) are generated through fermentation; the ratio of acetate, propionate, and butyrate generate is 60:25:15. Butyrate absorbed through the primary butyrate transporter MCT1 (mono carboxylate transports-1) in the intestines activates such SCFA receptors as GPR43 and GPR41. Butyrate has a strong anti-tumorigenic function. Butyrate is characterized by the fact that it has an effect on many cancer cells, contributes to the coordination of functions in the cells, and induces cancer apoptosis. Butyrate activates caspase but inhibits the activity of HDAC (histone deacetylase), so as to induce apoptosis. In addition, it increases p53 expression, so as to induce cell cycle arrest and apoptosis. Anti-inflammation actions of SCFA include the reduction of IL-8 expression in intestinal epithelial cells, the inhibition of NO synthesis, and the restraint of the activity of NF-${\kappa}B$ (nuclear factor ${\kappa}B$), so as to suppress the occurrence of cancers caused by inflammation. Butyrate plays an important role in maintaining physiological functions of intestinal mucous membranes and is used as a cure for inflammatory bowel disease (IBD).

• Nutritional Sciences
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• v.5 no.4
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• pp.175-183
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• 2002

To compare the effects of various types of dietary fiber on microbial production of short-chain fatty acids (SCFA) and on colon cell proliferation which is used as an intermediate biomarker for colon carcinogenesis, groups of 10 male Sprague-Dawley rats were fed one of four fiber-supplemented diets (6% cellulose, 6% pectin, 6% polydextrose, and a mixture of 3% cellulose and 3% polydextrose) for three weeks. As a control, a fiber-free diet was fed to a separate group of 10 rats. Cell proliferation was measured by in vivo incorporation of bromodeoxyuridine into DNA in the proximal and distal colon, respectively. Luminal concentrations of SCFA were measured by gas chromatography. Dietary fiber significantly influenced microbial production of SCFA in the colon; pectin supplementation produced the highest concentrations of luminal SCFA in both the proximal and distal colon (p<0.05). The degree of individual SCFA production was characterized by a relatively higher increase in butyrate production by the pectin-supplemented diet, and in propionate production by the polydextrose-supplemented diet, resulting in alterations of the molar ratios of acetate, propionate and butyrate. There were significant differences in colon cell proliferation among the diet groups; the pectin-supplemented diet produced a significantly higher effect on cell proliferation of distal colonic epithelial cells (p＜0.05), and the polydextrose-supplemented diet produced an intermediate effect compared to the fiber-free or cellulose-supplemented diet. Increased cell proliferation was correlated to increased luminal concentrations of butyrate in the proximal colon and to increased luminal concentrations of propionate and butyrate in the distal colon (p<0.05). Therefore, these data suggest that dietary fiber may modulate colon cell proliferation by altering luminal SCFA concentrations, particularly butyrate and perhaps propionate. In addition, the present study is the first finding that has demonstrated a relative increase in colon cell proliferation due to supplementation with polydextrose, suggesting that the overuse of this artificially synthesized polysaccharide in food processing technology needs to be carefully evaluated from the public health point of view.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3351-3356
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• 2014

Recently, Importance of studying based on biomass materials have increased due to the concern about plastic waste problems. Cellulose acetate butyrate (CAB) is a potential alternative to petroleum-based plastics because of its biodegradable property. Poly(ethylene-co-isosorbide terephthalate) (PEIT) is bio-based plastic, produced by isosorbide monomer. In this study, CAB/PEIT blends were prepared by solution blending to improve thermal stability of CAB. CAB and PEIT were dissolved in chloroform, and then precipitated in ethanol. To evaluate the compatibility of CAB/PEIT blends, the morphology and glass transition behaviors were analyzed by FE-SEM and DMA, respectively. TGA results revealed the improved thermal stabilities of the PEIT-rich and 50:50 compositions. No new or changed crystal structures were observed in the XRD result. Finally, CAB/PEIT solution blends showed good compatibility in overall compositions.

• Microbiology and Biotechnology Letters
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• v.16 no.3
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• pp.213-218
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• 1988

Studies were made to optimize the simultaneous saccharification and fermentation (SSF) of rice straw to produce butanol using Clostridium acetobutylicum KCTC 1037 and a cellulolytic enzyme preparation from Trichoderma viride. The fermentation was inhibited when the liquid enzyme preparation from Novo was used, whilst a successful fermentation was achieved in the SSF using the enzyme manufactured by Pacific Chemical Co. The minimum cellulase concentration for the successful fermentation of pure cellulose was found to be 4 IU/g of substrate used. Alkaline treatment was better method for the fermentation of rice straw by the system. SSF using 25％ alkaline treated rice straw produced 150 mM butanol, 90 mM acetone. On the other hand, fermentation of ball milled rice straw was mainly acidogenic producing 98 mM acetate and 64 mM butyrate with less than 20 mM butanol. These results show that rice straw contains (a) specific inhibitor(s) for solventogenesis which is destroyed or soluble in alkali.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4081-4086
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• 2014

Cellulose acetate butyrate (CAB) is a biodegradable resin with excellent optical properties, but it is difficult to apply film process. In this study, an attempt was made to improve the processability of CAB using polyactic acid and the mechanical properties using an impact modifier. Polylacitc acid (PLA)/Cellulose acetate butyrate (CAB) blends with an impact modifier were prepared using a twin screw extruder. The temperature range was $140^{\circ}C$ to $200^{\circ}C$, and the screw speed was fixed to 200 rpm. To evaluate the miscibility of impact modified CAB/PLA, the glass transition behavior and morphology were observed by DSC and FE-SEM. The mechanical properties were investigated by dynamic mechanical analysis (DMA) and a Universal Testing Machine (UTM). In addition, the effect of an impact modifier in the polymer matrix was determined using a notched Izod impact strength tester. Finally, the PLA/CAB/impact modifier 75/25/10 ratio was found to be a compatible system. In the 10wt.% impact modifier, the sample had a 4 times higher izod impact strength than the non-toughening composition.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.237-241
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• 1997

Lipase (EC 3.1.1.3) in the culture filtrate of Streptomyces coelicolor A3(2) was active on ${\alpha}$-naphthyl-butyrate as well as on various triacylglycerols with different lengths of acyl chains. The extracellular lipase was purified 15-fold by ammonium sulfate fractionation, Sephadex G-100, DEAE-Cellulose and Phenyl-Sepharose CL4B column chromatography with overall yield of 16%. It showed an molecular weight of 34.7 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme activity with tributyrin as substrate was optimal at pH 8.0~9.0 and at $37^{\circ}C$. The enzyme activity decreased when the chain length of acyl group of triacyglycerol increased. A-factor, a hormone-like regulator of Streptomyces differentiation inhibited the lipase activity, which might corelate with the low enzyme activity in early exponential growth phase.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.278-282
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• 1988

Rice straw was used in the acetone-butanol fermentation by semultaneous saccharification and fermentation (SSF) using Clostridium acetobutylicum and cellulolytic enzyme. Over 230 mM of solvent was produced from alkali treated rice straw of from ball-milled microcrystalline cellulose whilst only acidic fermentation products were formed from ball-milled rice straw. From the results it is concluded that rice straw used in the study contained an inhibitor for the solventogenesis by the organism which is insoluble in water and some organic solvent and destroyed by alkaline treatment.