• 대한화장품학회지
• /
• 제39권2호
• /
• pp.159-166
• /
• 2013

본 연구에서는 새로운 미백소재를 개발하기 위해 적양 에탄올추출물을 효소처리 후 EtOAc 분획물(AJE)을 준비하여 in vitro 상에서 이들의 tyrosinase 저해활성과 세포 수준에서의 멜라닌 합성 저해효과를 측정하였다. AJE는 mushroom tyrosinase의 활성에는 영향을 미치지 않았으나 B16-F1 melanoma cell을 이용한 멜라닌 합성 저해효과에 있어서 농도 의존적으로 멜라닌 합성을 저해하여, $40{\mu}g/mL$의 농도에서 52% 이상의 저해효과를 나타내었다. 이러한 멜라닌 합성 저해효과에 대한 작용 기전을 확인하기 위해 western blot을 통해 멜라닌 합성 경로에 관련된 단백질의 발현을 측정하였다. 그 결과 멜라닌 합성에 관여하는 효소인 tyrosinase related protein 1 (TRP-1)의 발현을 억제하였고, 이를 조절하는 전사인자인 microphthalmia associated transcription factor (MITF) 발현 역시 효과적으로 억제하였다. 또한 extracellular signal-regulated kinase (ERK) pathway를 활성화시킴으로써 phosphorylated extracellular signal-regulated kinase (p-ERK)의 발현을 상당히 증가시키는 것을 확인할 수 있었다. 이러한 결과는 AJE가 멜라닌 합성의 신호전달 경로 중 ERK pathway의 활성화를 통해 MITF의 분해를 촉진시키고 이로 인해 MITF의 발현을 감소시키며, 그 결과 멜라닌 합성에 관여하는 효소 중 TRP-1의 발현을 감소시킴으로써 멜라닌 합성을 저해하는 것으로 사료되며, 따라서 AJE는 미백용도의 기능성 원료로서의 가능성이 큰 것으로 판단된다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제29권3호
• /
• pp.297-305
• /
• 2005

The evaporation heat transfer coefficient of $CO_2$ (R-744) in a horizontal tube was investigated experimentally. The experiments were conducted without oil in a closed refrigerant loop which was driven by a magnetic gear pump. The main components of the refrigerant loop are a receiver. a variable-speed pump. a mass flow meter. a pre-heater and evaporator (test section). The test section consists of a smooth. horizontal stainless steel tube of 7.75 mm inner diameter. The experiments were conducted at mass flux of 200 to $500\;kg/m^{2}s$. saturation temperature of $-5^{\circ}C\;to\;5^{\circ}C$. and heat flux of 10 to $40\;kW/m^2$. The test results showed the evaporation heat transfer of $CO_2$ has greatly effect on more nucleate boiling than convective boiling. The evaporation heat transfer coefficients of $CO_2$ are highly dependent on the vapor quality. heat flux and saturation temperature. The evaporation heat transfer coefficient of $CO_2$ is very larger than that of R-22 and R-134a. In making a comparison between test results and existing correlations. the present experimental data are the best fit for the correlation of Jung et al. But it was failed to predict the evaporation heat transfer coefficient of $CO_2$ using by the existing correlation. Therefore. it is necessary to develop reliable and accurate predictions determining the evaporation heat transfer coefficient of $CO_2$ in a horizontal tube.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제13권4호
• /
• pp.167-174
• /
• 2005

The evaporation heat transfer coefficient of $CO_2$ (R-744) in a horizontal tube was investigated experimentally. The experiments were conducted without oil in a closed refrigerant loop which was driven by a magnetic gear pump. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and evaporator (test section). The test section consists of a smooth horizontal stainless steel tube of 7.75 mm inner diameter. The experiments were conducted at mass flux of 200 to $500kg/m^2s$, saturation temperature of $-5^{\circ}C\;to\;5^{\circ}C$, and heat flux of 10 to $40kW/m^2$. The test results showed the evaporation heat transfer of $CO_2$ has greater effect on nucleate boiling than convective boiling. The evaporation heat transfer coefficient of $CO_2$ is highly dependent on the vapor quality, heat flux and saturation temperature. The evaporation heat transfer coefficient of $CO_2$ is very larger than that of R-22 and R-134a. In comparison with test results and existing correlations, the best fit of the present experimental data is obtained with the correlation of Jung et al. But the existing correlations failed to predict the evaporation heat transfer coefficient of $CO_2$. Therefore, it is necessary to develop reliable and accurate predictions determining the evaporation heat transfer coefficient of $CO_2$ in a horizontal tube.

• 천문학회보
• /
• 제39권1호
• /
• pp.57.1-57.1
• /
• 2014

We present the preliminary results of CO outflow survey toward the 56 Very Low Luminosity Object (VeLLO) candidates at CO J=2-1 and J=3-2 transitions with two radio telescopes of the Caltech Submillimeter Observatory (CSO) and the Atacama Submillimeter Telescope Experiment (ASTE). The survey is aimed to understand the origin of the formation of low-mass stars or substellar objects. The VeLLO is a very faint (${\leq}0.1$ $L_{\odot}$) object deeply embedded in dense molecular clouds and believed to be a proto-brown dwarf which will be a brown dwarf or a faint protostar which has just formed with little mass accretion or which is in quiescent stage of episodic accretion. The candidates were searched for over all nearby ($d{\leq}450$ pc) Gould belt clouds and listed in a new catalogue of the VeLLO candidates by Kim et al. (2014 submitted). To diagnose present status and future fate of the VeLLOs, we conducted a systematic observation for the CO molecular outflows of the 56 VeLLOs to infer how accretion is being made around the VeLLOs. We found 17 VeLLO candidates either having a prominent wing in line profiles or showing bipolar intensity distribution of high velocity components. We will discuss the physical properties of these CO outflows and the identity of the VeLLO candidates.

• 한국자동차공학회논문집
• /
• 제16권3호
• /
• pp.30-37
• /
• 2008

The evaporation pressure drop of $CO_2$ (R-744) in horizontal tubes was investigated experimentally. The experiments were conducted without oil in a closed refrigerant loop which was driven by a magnetic gear pump. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and evaporator (test section). The test section consists of a smooth, horizontal stainless steel tube of 7.75 and 4.57 mm inner diameter. The experiments were conducted at saturation temperature of $-5^{\circ}C\;to\;5^{\circ}C$, and heat flux of 10 to $40kW/m^2$. The test results showed the evaporation pressure drop of $CO_2$ are highly dependent on the vapor quality, heat flux and saturation temperature. The pressure drop measured during the evaporation process of $CO_2$ increases with increased mass flux, and decreases as the saturation temperature increased. The evaporation pressure drop of $CO_2$ is very lower than that of R-22. In comparison with test results and existing correlations, the best fit of the present experimental data is obtained with the correlation of Choi et al. But existing correlations failed to predict the evaporation pressure drop of $CO_2$. Therefore, it is necessary to develop reliable and accurate predictions determining the evaporation pressure drop of $CO_2$ in a horizontal tube.

• 대한본초학회지
• /
• 제34권1호
• /
• pp.13-21
• /
• 2019

Objectives : This clinical trial is performed to investigate the effect of improving the hypersensitivity reaction and the safety of powdered ethanol extract Codonopsis lanceolata (S. et Z.) Trautv. for allergic patients. Methods : This study was randomized, double blinded, placebo-controlled clinical trial. 60 allergic rhinitis subjects were randomly assigned to Treatment group(n=30) and Control group(n=30). They were received the test substance or placebo in their $1^{st}$ and $2^{nd}$ visit, and took it once a day, 1 powder bag per 1 time, for 8 weeks. The freeze dried powder of Codonopsis lanceolata (S. et Z.) Trautv. was mixed with 30% ethanol and the filtrate was collected thrice with constant stirring of the mixture. The placebo was prepared in the same form as the test substance by replacing with corn starch. Total Nasal Symptom Score(TNSS) questionnaires and laboratory tests were performed at the screening and last visit to evaluate the efficacy. And to assess safety, vital signs and adverse events were confirmed at every visit. Statistical analysis about the result was performed using SAS 9.4. Results : In treatment group, there was a significant decrease in B cell after taking the test substance(p<0.005). And there was a statistically significant difference between groups(p<0.005). Changes in nasal symptoms were not statistically significant between groups, and both groups showed statistically significant differences before and after the test(p<0.0001). Also there were no adverse events associated with the clinical trial product. Conclusions : This clinical trial showed that Codonopsis lanceolata (S. et Z.) Trautv. extract was helpful in improving the hypersensitivity reaction in allergic patients without significant side effects.

• Natural Product Sciences
• /
• 제11권1호
• /
• pp.10-12
• /
• 2005

Flavonol galactosides were isolated from the EtOAc fraction of Artemisia apiacea by repeated column chromatography. Their structures were elucidated as $isorhamnetin-3-O-{\beta}-D-galactoside$ (1) and $quercetin-3-O-{\beta}-D-galactoside$ (2) by chemical and spectroscopic analysis. This is the first report on the isolation of compound 2 from this plant.

• 자원환경지질
• /
• 제40권6호
• /
• pp.727-738
• /
• 2007

운봉지역 하상퇴적물에 대한 지구화학적 특성규명을 통해, 주성분원소 및 미량원소에 대한 자연 배경치를 제시하고, 그 기반암(압쇄상화강암, Kim et al., 1992)과의 비교를 통해 지구화학적 재해에 대해 예견하고자 한다. 73개의 하상퇴적 물시료를 물이 흐르고 있는 1차 수계를 대상으로 채취하였고, XRD, XRF ICP-AES, NAA를 이용하여 주성분원소 및 미량성분원소를 분석하였다. 운봉지역의 주성분원소 함량은 $SiO_2\;36.94{\sim}65.39 wt.%,\;Al_2O_3\;10.15{\sim}21.77wt.%,\;Fe_2O_3\;3.17{\sim}10.90wt.%,\;CaO\;0.55{\sim}5.27wt.%,\;MgO\;0.52{\sim}4.94wt.%,\;K_2O\;1.38{\sim}4.54wt.%,\;Na_2O\;0.49{\sim}3.36wt.%,\;TiO_2\;0.39{\sim}1.27wt.%,\;MnO\;0.04{\sim}0.22wt.%,\;P_2O_5\;0.08{\sim}0.54wt.%$의 범위를 보이며, 미량성분 및 희토류원소 함량은, $Cu\;4.8{\sim}134ppm,\;Pb\;24.2{\sim}82.5ppm,\;Sr\;95.9{\sim}739ppm,\;V\;19.9{\sim}124ppm,\;Zr\;52.9{\sim}145ppm,\;Li\;25.2{\sim}3.3ppm,\;Co\;3.87{\sim}50.0ppm,\;Cr\;17.4{\sim}234ppm,\;Hf\;3.93{\sim}25.2ppm,\;Sc\;4.60{\sim}20.6ppm,\;Th\;3.82{\sim}36.9ppm,\;Ce\;45.7{\sim}243ppm,\;Eu\;0.89{\sim}2.69ppm,\;Yb\;1.42{\sim}5.18ppm$의 범위를 보인다. 주성분원소의 함량비교에서 CaO, $Na_2O,\;K_2O$ 함량은 하상퇴적물에서 기반암(압쇄상화강암류, Kim et al., 1992)인 압쇄상화강암류보다 높게 나타난다. 그리고 $Al_2O_3$와 $SiO_2$는 하상퇴적물과 기반암(압쇄상화강암류, Kim et al., 1992) 모두에서 높은 상관관계를 보인다. 하상퇴적물에서는 $SiO_2$ 함량이 높아질수록 희토류원소 함량도 같이 증가하는 특징을 보이나, 압쇄상화강암류에서는 $SiO_2$ 함량이 높아질수록 희토류원소 함량은 감소하는 특징을 보인다.

• 한국대기환경학회지
• /
• 제21권4호
• /
• pp.459-469
• /
• 2005

In recent years, concerns have been growing globally regarding greenhouse gases. Open burning of biomass causes emission of a number of greenhouse and other gases and substances. This paper studied an analysis on the characteristics of four types of biomass using duel type cone calorimeter. Cone calorimeter is widely used for assessing combustibility of materials in Europe. As a result, we evaluated several characteristics of biomass, such as heat released rate, smoke production rate, CO, $CO_2$ production and mass loss rate, and so on. $CO_2$ is currently responsible for over $60\%$ of the enhanced greenhouse effect, and may be the most important contributor to future. $CO_2$ production for biomass in the range of $1.74\~1.99kg/kg$ is similar to previous research conducted by Bhattacharya et al. (2002a).

• Journal of Applied Biological Chemistry
• /
• 제62권3호
• /
• pp.275-280
• /
• 2019

약용식물 67종의 생리활성 부위를 대상으로 열수 추출물이 in vitro에서 xanthine oxidase의 활성에 미치는 효과를 확인하였다. 약용식물 중에서 황금, 지각, 하수오, 갈근, 청피, 복분자, 녹차 및 지실 추출물은 xanthine oxidase의 활성을 강력하게 저해하여 항통풍 천연소재로서의 활용 가능성이 높게 나타났다. 하수오 뿌리 추출물은 열과 pH에 대한 안정성이 우수하였고, 농도에 비례하여 xanthine oxidase의 활성을 저해하였다. 하수오 추출물은 2.0 mg/0.1 mL의 농도에서 xanthine oxidase에 대해 73.8%의 저해 효과를 나타내었다.