• 한국환경보건학회지
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• 제17권1호
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• pp.120-128
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• 1991

Saccharomyces cerevisiae was immobilized by incubating iron oxides with calcium alginate, and by polyacrylamide entrapment to use repeatedly for the conversion of glucose to ethanol. Magnetic and non-magnetic immobilized yeast and polyacrylamide immobilized yeast were compared with the native yeast a batch-fermentation of ethanol from glucose. Three kinds of immobilized yeast tended almost identically, having ethanol productivity as well as the final yield about the same to what was found for the native yeast. The long-term operational stability of three kinds of immobilized yeast were significant difference according as immobilized yeast activation or non-activation before ethanol fermentation. In the non-activation they lost their activity of fermentation rapidly in the beginning stage an slower at a later stage. On the other hand, in the activation with nutrient media, their activities were increased to some extent and stable in the later stage. The cell count of three kinds of immobilized yeast after activiation by incubating nutrient media, increased by a factor of about 45 to 48, whereas the fermenting capacity increased by a factor of 174 to 178. In the prearation of immobilized biocatalysts, magnetic matter does not seem to have any adverse affect on the properties of the microorganism. The immobilized biocatalysts by utilizing magnetic matter have some advantages, especially in application of viscous media or insoluble particle-containing media, for this work was linked with microbial utilization of environmental wastes and elimination of envirnmental pollutant.

• 한국안전학회지
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• 제31권1호
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• pp.66-73
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• 2016

Lyocell fibers were used as a precursor in order to improve yield and strength of cellulose-based precursor while manufacturing activated carbon fiber(ACF). Lyocell fibers as a precursor for the preparation of ACF were surface-modified by reaction with 3-aminopropyltriethoxysilane(APTES) and pre-treated with KOH and H3PO4. Using aforementioned precursor, ACFs were prepared by a series of stabilization, carbonization and activation process at high temperatures. On each process, FT-IR, TGA, UTM and SEM were used to observe fibers' physical properties including structure and porous surfaces. FT-IR results proved that surface modification was achieved during stabilization, carbonization and activation process. TGA results during carbonization process found that surface modified fibers with APTES 0.02 mol(A2) showed higher thermostability, and extended pre-treatment increased yield. Especially, yield was found to have an increase of 10~20 wt% with surface modification during activation process. UTM results showed that tensile strength has the same order of concentration of APTES after surface modification, however, was found to show lower tensile strength than lyocell fibers after stabilization process. SEM results revealed that more homogeneous porosity control could be proceed after modifying the surface for the effective removal of hazardous substances.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2008년도 추계학술대회
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• pp.54-57
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• 2008

This study is aimed to inspect how the different sensitivities in Behavioral activation system (BAS) and Behavioral inhibition system (BIS) modulate on the properties of physiological responses stimulated by positive or negative affective sound. We measured the electroencephalogram (EEG) of 32 students, consisted of four groups depending on the BAS and BIS sensitivities, during listening to meditation music or noise. The EEG was recorded at Fp1 and Fp2 sites. After listening to music or noise, subjects reported the affect induced by the sound. For EEG, the power in the alpha band at Fp2, especially in the alpha-2 band (9.0-11.0 Hz) increased during the subjects listening to music, while the power at Fp1 increased during noise. During listening to meditation music, there is a tendency that the left-sided activation in prefrontal cortex (PFC) is positively correlated with the difference of BAS(Z)-BIS(Z). During listening to noise, there is a tendency that the right-sided activation in PFC is dominant in case any of the sensitivity of BAS or BIS is high. From these results we suggest that the physiological responses of different individuals in BAS and BIS react differently under the same emotionally provocative challenge.

• KSBB Journal
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• 제13권2호
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• pp.162-167
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• 1998

The adsorption behaviors of two major cellulase components, endo I and exo II, from Trichoderma viride were investigated using $\alpha$-celluloses with different correlation crystallinity index(Cc) as substrates. The adsorption of cellulase enzyme components was significantly affected by the reaction condition and the physicochemical properties of the cellulose. The $\alpha$-cellulose was hydrolyzed in the presence of cellulase for various periods. The correlation crystallinity index of $\alpha$-cellulose increased with increasing the hydrolysis time. The adsorption was apparently found to obey the first-order kinetics, and the adsorption activation energy(Ea) was calculated from the adsorption rate constant(ka). The value of adsorption rate constant for endo I was larger than that of exo II. This means that endo I are adsorbed more rapidly than exo II. With the increase in correlation crystallinity index, the values of the adsorption rate constants for endo I and exo II decreased, respectively. The activation energy for the adsorption of exo II on the cellulose also was larger than that of endo I. Also adsorption activation energy of endo I and exo II increased with an increase in the crystallinity of sample cellulose.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.475-479
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• 2002

Capsaicin, a major pungent constituent of red pepper (Capsicum annuum L.) possesses a vast variety of pharmacologic and physiologic activities. Despite its irritant properties, the compound exerts anti-inflammatory and anti-nociceptive effects. Previous studies from this laboratory revealed that capsaicin, when topically applied onto dorsal skin of female ICR mice, strongly attenuated activation of NF-kB and AP-1 induced by the typical tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), which may account for its anti-tumor promoting activity in mouse skin. In the present work, we have found that capsaicin suppresses TPA-stimulated activation of NF-kB through inhibition of $IkB{\alpha}$ degradation and blockade of subsequent nuclear translocation of p65 in human pro myelocytic leukemia HL-60 cells. Methylation of the phenolic hydroxyl group of capsaicin abolished its inhibitory effect on NF-kB DNA binding. Likewise, TPA-induced activation of AP-1 was mitigated by capsaicin treatment.

• Natural Product Sciences
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• 제25권2호
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• pp.165-171
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• 2019

Although the functions of a standardized extract of Gingko biloba leaves (EGb $761^{(R)}$) has been reported with regard to neurobiological properties, no attention has been paid to the impact of EGb $761^{(R)}$ on the neuronal regulation of energy homeostasis. To evaluate the hypothesis that EGb $761^{(R)}$ affect the secretion of peptide tyrosine tyrosine (PYY) and the activation of free fatty acid receptor 4 (FFA4), which are involved in the neuronal circuitries that control energy homeostasis by inducing the transfer of information about the influx of energy to the brain, we examined whether EGb $761^{(R)}$ can stimulate PYY secretion in the enteroendocrine NCI-H716 cells and if EGb $761^{(R)}$ can activate FFA4 in FFA4-expressing cells. In NCI-H716 cells, EGb $761^{(R)}$ stimulated PYY secretion and the EGb $761^{(R)}$-induced PYY secretion was involved in the increase in intracellular $Ca^{2+}$ concentration and the activation of FFA4. Furthermore, in FFA4-expressing cells, EGb $761^{(R)}$ activated FFA4. These results suggest that EGb $761^{(R)}$ may affect the control of energy homeostasis via the regulation of PYY secretion and FFA4 activation.

• Carbon letters
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• 제16권2호
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• pp.78-85
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• 2015

Activated carbons (ACs) were prepared by activation of coal tar pitch (CTP) in the range of $700^{\circ}C-1000^{\circ}C$ for 1-4 h using potassium hydroxide (KOH) powder as the activation agent. The optimal activation conditions were determined to be a CTP/KOH ratio of 1:4, activation temperature of $900^{\circ}C$, and activation time of 3 h. The obtained ACs showed increased pore size distribution in the range of 1 to 2 nm and the highest specific capacitance of 122 F/g in a two-electrode system with an organic electrolyte, as measured by a charge-discharge method in the voltage range of 0-2.7 V. In order to improve the performance of the electric double-layer capacitor electrode, various mixtures of CTP and petroleum pitch (PP) were activated at the optimal activation conditions previously determined for CTP. Although the specific capacitance of AC electrodes prepared from CTP only and the mixtures of CTP and PP was not significantly different at a current density of 1 A/g, the AC electrodes from CTP and PP mixtures showed outstanding specific capacitance at higher current rates. In particular, CTP-PP61 (6:1 mixture) had the highest specific capacitance of 132 F/g, and the specific capacitance remained above 90% at a high current density of 3 A/g. It was found that the high specific capacitance could be attributed to the increased micro-pore volume of ACs with pore sizes from 1 to 2 nm, and the high power density could be attributed to the increased meso-pore volume.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 국제심포지움
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• pp.88.2-98
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• 2002

A wide arry of naturally occurring substances particularly those present in dietary and medicinal plants, have been reported to possess substantial cancer chemopreventive properties. Certain phytochemicals retain strong antioxidative and anti-inflammatory properties which appear to contribute to their chemopreventive or chemoprotective activities. Inducible cyclooxygenase(COX-2) and nitric oxide synthase (iNOS) are important enzymes that mediate inflammatory processes. There is some evidence that expression of both COX-2 and iNOS is co-regulated by the eukaryotic transcription factor NF-$textsc{k}$B. Increased expression of COX-2 and/or iNOS has been associated with pathophysiology of certain types of human cancers as well as inflammatory diseases. Since inflammation is closely linked to tumor promotion, substances with potent anti-inflammatory activies are anticipated to exert chemopreventive effects on carcinogenesis, particularly in the promotion stage. An example is curcumin, a yellow pigment of turmeric (Curcuma longa L., Zingiberaceae), that strongly occurring diaryl heptanoids structurally related to curcumin have substantial anti-tumor promotional activities in two-stage mouse skin carcinogenesis. Thus, yakuchinone A [1-(4'-hydroxy-3'-methoxyphenyl)-7-phenyl-3heptanone] and yakuchinone B [1-(4'-hydroxy-3'methoxyphenyl)-7-phenylhept-1-en-3-one] present in Alpinia oxyphylla Miquel (Zingiberacease) attenuate phorbol ester-induced inflammation and papilloma formation in female ICR mice. These diarylheptanoids also suppressed phorbol ester-induced activation of epdermal ornithine decarboxylase and its mRNA expression when applied onto shaven backs of mice. Yakuchinone A and B as well as curcumin inhibited phorbol ester-induced expression of COX-2 and iNOS and their mRNA in mouse skin via inactivation of NF-$textsc{k}$B. Capsaicin, a major pungent ingredient of red pepper also attenuated phorbol ester-induced NF-$textsc{k}$B activation. Similar suppression of COX-2 and iNOS and down-regulation of NF-$textsc{k}$B activation for its DNA binding were observed with the ginsenosied Rg3 and the ethanol extract of Artemisia asiatica. We have also found that certain anti-inflammatory phytochemicals exert inhibitory effects on phorbol ester-induced COX-2 expression and NF-$textsc{k}$B activation in immortalized human breast epithelial (MCF-10A) cells in culture. One of the plausible mechanisms undelying inhibition by aforementioned phytochemicals of phorbol ester-induced NF-$textsc{k}$B activation involves interference with degragation of the inhibitory unit, I$textsc{k}$Ba, which blocks subsequent nuclear translocation of the functionally active p65 subunit of NF-$textsc{k}$B. the activation of epidermal NF-$textsc{k}$B by phorbol ester and subsequent induction of COX-2 hence appear to play an important role in intracellular signaling pathwasy leading to tumor promotion and targeted inhibition of NF-$textsc{k}$B may provide a new promising cancer chemopreventive strategy.

• Carbon letters
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• 제24권
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• pp.62-72
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• 2017

The aim of this work was to evaluate the dielectric properties of impregnated and activated palm kernel shells (PKSs) samples using two activating agents, potassium carbonate ($K_2CO_3$) and sodium hydroxide (NaOH), at three impregnation ratios. The materials were characterized by moisture content, carbon content, ash content, thermal profile and functional groups. The dielectric properties were examined using an open-ended coaxial probe method at various microwave frequencies (1-6 GHz) and temperatures (25, 35, and $45^{\circ}C$). The results show that the dielectric properties varied with frequency, temperature, moisture content, carbon content and mass ratio of the ionic solids. PKSK1.75 (PKS impregnated with $K_2CO_3$ at a mass ratio of 1.75) and PKSN1.5 (PKS impregnated with NaOH at a mass ratio of 1.5) exhibited a high loss tangent ($tan{\delta}$) indicating the effectiveness of these materials to be heated by microwaves. $K_2CO_3$ and NaOH can act as a microwave absorber to enhance the efficiency of microwave heating for low loss PKSs. Materials with a high moisture content exhibit a high loss tangent but low penetration depth. The interplay of multiple operating frequencies is suggested to promote better microwave heating by considering the changes in the materials characteristics.

• 폴리머
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• 제27권3호
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• pp.183-188
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• 2003

유전체 분광계를 사용하여 불소함유 에폭시 수지, 벤조트리플루오라이드의 다이글리시딜 에테르(FER)/다이아미노다이페닐메탄 (DDM)과 비스페놀 A의 다이글리시딜 에테르 (DGEBA)DDM 시스템의 유전상수를 측정하였으며, DMA와 TGA에 의한 열분석을 통하여 유리 전이 온도 및 열분해 개시온도, 최대 무게 감량시 온도, 그리고 분해 활성화 에너지 등 열안정성 인자를 고찰하였다. 경화된 시편의 기계적 물성은 파괴 인성, 굴곡강도 및 충격강도 실험을 통하여 알아보았으며, 주사전자 현미경을 사용하여 시편의 파단 특성을 조사하였다. 실험 결과, DGEBA/DDM 시스템에 비해 FER/DDM 시스템은 낮은 유전 상수를 나타내었으며, 경화된 시편의 기계적 물성은 높은 값을 나타내었다. 이는 trifluoromethyl (CF$_3$) 기의 도입으로 인하여 전기적 특성과 기계적 물성이 증가한 것으로 사료된다.