• Journal of Ginseng Research
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• 제31권2호
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• pp.74-78
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• 2007

Multi-drug resistance (MDR) is a major problem in cancer chemotherapy and has often ended up with termination of the therapy. The aim of this study was to identify any fractions of Korean red ginseng that would be effective in modulating for MDR. Although ginsenosides have been reviewed as possible MDR modulators, the MDR modulation activity of the other component is unknown. Therefore, a red ginseng was extracted with methanol, ether, ethylacetate, and n-butanol, followed by several fractionations by silica gel chromatography. And the activity of MDR modulating for these fractions was examined via sulforrhodamine B assay. We have found that several ether fractions, as nonsaponin components are effective on MDR modulation. We have expect that these results helpful to improvement of cancer chemotherapy.

• 한국재료학회지
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• 제13권12호
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• pp.796-800
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• 2003

The polypyrrole prepared with pyrrole monomer, APS and DBSA was synthesized by chemical Polymerization at $V^{\circ}C$ under atmosphere conditions. After dissolving polypyrrole powder to the chloroform including DBSA, polypyrrole film was prepared on the alumina substrate with an interdigitated electrode by using the dip-coating method. This film was soaked in methanol solvent for 1 h at room temperature and heated to $70^{\circ}C$ for 4 h in $N_2$. Initial resistance was increased with the increasing humidity and decreasing temperature. The sensitivity was increased with lower humidity and decreasing temperature. The best linearity was achieved at $25^{\circ}C$ and low humidity of 0%.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.196-208
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• 2018

The effect of channel-system of zeolite on methanol-to-DME reaction was studied. Results revealed that channels size and topology affect catalyst lifetime, type and location of coke precursors. FER and MFI showed the best resistance towards coke deposition, whilst fast deactivation was observed on MOR. Although the higher concentration and strength of acid sites, FER structure formed a lower coke amount, preferably located within the pores, while coke cluster deposited on the external surface of MOR. Analysis of acid sites distribution and strength was performed during deactivation-regeneration process. Coke location assessment was also supported by molecular simulations.

• 생약학회지
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• 제53권1호
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• pp.21-28
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• 2022

Sparassis crispa is an edible mushroom that has been widely utilized in Japan and Korea. It has various biological activities, such as anti-hypertensive, anti-allergic, anti-diabetic, anti-inflammatory, anti-angiogenic, and anti-cancer effects. In this study, we investigated the anticancer activity and underlying molecular mechanism of chloroform fraction of methanol extract of S. crispa (CESP) against cervical cancer stem cells (CSCs), which contribute to tumor initiation, recurrence, and resistance to therapy of human cervical cancer. CESP effectively inhibited the proliferation, tumorsphere formation, and migration of HeLa-derived cervical CSCs by promoting apoptosis. In addition, CESP significantly downregulated the expression of key cancer stemness markers, including integrin α6, CD133, CD44, ALDH1A1, Nanog, Oct-4, and Sox-2, in HeLa-derived cervical CSCs. Furthermore, CESP remarkably suppressed in vivo tumor growth of HeLa-derived cervical CSCs in a chick embryo chorioallantoic membrane (CAM) model. Therefore, our findings suggest that CESP has potential as a natural medicine for the prevention and treatment of cervical cancer by targeting CSCs.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1433-1438
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• 2007

Characteristics of a phase change type micro actuator have been studied. The micro actuator has been designed for a micro-pump in an active direct methanol fuel cell(DMFC), consisting of an actuating chamber, a membrane, an electric heater, and a sensor of resistance temperature detector (RTD). In the present study, researches have been focused on the response of the actuator to control algorithm of the heater. The experiments demonstrated that the displacement of the membrane increase with temperature variation which is a function of applied voltage, duty ratio, and operating frequency of heating. The results also showed that operation of the actuator with high voltage at small duty of heating is more efficient than the same power consumption of heating with low voltage at large duty.

• Natural Product Sciences
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• 제18권4호
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• pp.211-214
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• 2012

Since 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is the key metabolic enzyme of prostaglandin $E_2$ ($PGE_2$), inhibition of 15-PGDH is supposed to facilitate various physiological functions by increasing $PGE_2$. Methanol extract of Artemisia argyi (AAME) inhibited 15-PGDH ($IC_{50}$: $13.13{\mu}g/mL$) with relatively low cytotoxicity ($IC_{50}$: $415.00{\mu}g/mL$) and elevated extracellular $PGE_2$ levels in HaCaT cells. Real-time PCR analysis showed that AAME decreased significantly mRNA expression of PG transporter (PGT) in HaCaT cells. These results indicate that AAME could be applicable to functional materials as a 15-PGDH inhibitor and PGT expression inhibitor for the upregulation of extracellular $PGE_2$ level.

• 한국환경과학회지
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• 제17권2호
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• pp.211-224
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• 2008

Characteristics of the esterification reaction between free fatty acid in rice bran oil and methanol was investigated in the presence of catalysts, such as PTS(p-toluene sulfonic acid), Amberlyst 15 dry and SCX(silica gel based strong cation exchange resin). While reaction temperature was kept constant at $65^{\circ}C$, initial feed content of free fatty acid was varied from 100% to 1% by addition of pure free fatty acid which was previously made from rice bran oil. Also, the effect of mole ratio of methanol to fatty acid on the final conversion was examined. When esterification of pure free fatty acid was catalyzed by several acids, final conversions were increased in order of Amberlyst 15 dry, SCX and PTS. Using PTS catalyst, initially the reaction proceeded in homogeneous 2nd oder reaction mechanism. However, phase of reaction mixture changed from homogeneous to heterogeneous along the reaction time and then reaction rate was retarded by mass transfer resistance of methanol. Final conversion of free fatty acid in reaction mixture was depended on initial feed content of free fatty acid, and had maximum value at 30% of initial feed free fatty acid content for all kinds of catalysts used. And the final conversion was increased with mole ratio of methanol by the improvement of reaction rate. When initial feed free fatty acid content below 10% and the reaction was catalyzed by PTS, concentration of free fatty acid in reaction mixture was increased in the middle of reaction time by hydrolysis of triglyceride in reaction mixture. Also, if silica gel was added into the reaction mixture which had initial feed free fatty acid content below 50%, final conversion was increased by the adsorption of moisture produced. The SCX catalyst made the esterification reaction of free fatty acid to progress like in case of PTS catalyst. However, when initial feed free fatty acid content below 10%, concentration of free fatty acid in. reaction mixture was decreased monotonically and not increased in the middle of reaction time on the contrary to the case of PTS. Thus, SCX catalyst accomplished more high value of final conversion than PTS catalyst for the initial feed fatty acid content range from 50% to 5% In case of initial feed free fatty acid content of 1% and mole ratio of methanol was 2, concentration of free fatty acid in reaction mixture increased over the initial feed free fatty acid content for all kind of catalysts used. Although SCX catalyst was added into reaction mixture which had 1% of initial feed fatty acid content, final conversion was hardly raised by mole ratio of methanol.

• Applied Biological Chemistry
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• 제12권
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• pp.53-56
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• 1969

Bacillus subtilis var. M-181 생산(生産)한 amylase의 내열성(耐熱性)에 미치는 alcohol류(類)와 탄수화물(炭水化物)의 영향(影響)을 검토(檢討)하였다. 그 결과(結果)는 다음과 같다. 1. Alcohol류(類)에서는 glycerin, propylene glycol, ethylene glycol, ethyl alcohol, methyl alcohol 등(等)의 순(順)으로 내열성증가(耐熱性增加)의 효과(?果)가 있었으며 고급일가(高級一價) alcohol 과 dipropylene glycol 은 역효과(逆?果)를 나타냈다 2. Inositol은 당(糖) alcohol 보다 효과(?果)가 컸으며 당(糖) alcohol 중(中)에서는 mannitol, dulcitol, sorbitol의 순(順)으로 내열효과(耐熱效果)가 있었다. 3. 단당류(單糖類)에서는 mannose, galactose, xylose, glucose, arabinose, rhamnose, fructose 등(等)의 순(順)으로 내열효과(耐熱效果)가 있었다. 4. 소당류(小糖類)에서는 melibiose, lactose, maltose, sucrose, raffinose등(等)의 순(順)으로 내열효과(耐熱效果)가 있었다. 5. 다당류(多糖類)에서는 glycogen, soluble starch dextrin 등(等)의 순(順)으로 내열효과(耐熱效果)가 있었으며 inulin의 내열성(耐熱性) 증가효과(增加效果)가 인정(認定)할수 없었다.

• Elastomers and Composites
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• 제40권2호
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• pp.83-92
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• 2005

국제 환경규제에 적합한 자동차용 연료 호스를 개발하기 위하여, 배합조건을 달리한 FKM 고무재료를 내층재료로 하였을 경우, 기본물성을 비롯한 내열성, 내유성, 내연료성 및 투과성을 측정하고 연료 호스재료로서의 적합성을 조사하였다. 불소 함량이 증가함에 따라 불소 고무재료는 기본물성, 내열성, 내유성 및 내연료성의 증가를 보였으며, 66%, 69%, 71% FKM 혼합물에서 카본의 양을 20 phr로 하였을 때 연료 호스의 규격을 만족하는 것으로 나타났다. 이소옥탄과 톨루엔 그리고 가솔린과 메탄올을 혼합한 연료유로써 측정한 NBR 고무와 FKM 고무의 투과성에서 FKM 고무의 경우, 불소의 함량에 따라서 미세한 투과량의 차가 나타났으나 NBR 고무보다는 투과성이 매우 우수하였다. 또한 연료유의 성분비를 달리했을 때도 FKM 고무의 투과성에는 거의 영향이 없었으며, 투과성 실험을 거친 69% FKM 고무재료의 열적 특성에도 변화가 없었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.792-796
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• 2002

In this work, porous silicon(PS) layer is used as a sensing material to detect organic gases. To do this, PS sensors with membrane structure are fabricated. The sensors were made by applying the technologies of membrane formation by anisotropic etching of silicon, and PS layer formation by anodization in HF solution. From fabricated sensors, current-voltage (I-V) curves were measured against ethanol (called alcohol), methanol and acetone gases evaporated from 0.1 to 0.5% solution concentrations at $36^{\circ}C$. As the result, all curves showed rectifying behavior due to a diode structure between Si and PS, and the conductance of sensor devices increased largely with the organic solution concentration at high voltage of 5V.