• Title/Summary/Keyword: rate dependent

Search Result 3,171, Processing Time 0.03 seconds

Physicochemical Characteristics and Biological Activities of Artemisia Argyi H. (섬애약쑥의 이화학적 특성 및 생리활성)

  • Hwang, Cho-Rong;Seo, Weon-Tack;Bae, Won-Yoel;Kang, Min-Jung;Shin, Jung-Hye
    • Journal of Life Science
    • /
    • v.24 no.4
    • /
    • pp.377-385
    • /
    • 2014
  • This study was conducted to investigate the physicochemical characteristics and biological activities of water and 30%, 50%, 70%, 100% ethanol extracts from Artemisia Argyi H. and fermented Artemisia Argyi H. The yield was the highest in the 30% ethanol extract with Argyi H. at 29.74%. Total phenol and flavonoid contents were the highest in 70% ethanol extract with Argyi H. at 72.25 mg/g and 33.34 mg/g, respectively. The antioxidant activities of all extracts were significantly increased in a dose dependent manner. The 70% ethanol extract from Argyi H. show the highest level of DPPH, ABTS radical scavenging activity and bleaching inhibition activity in ${\beta}$-carotene linoleic acid system. Tyrosinase inhibition activity was also higher in the 70% ethanol extract, and the lowest in the 100% ethanol extract with Argyi H. at 50.01% and 11.44% at $500{\mu}g/ml$ concentration, respectively. At $250{\mu}g/ml$ concentration, the xanthin oxidase inhibition activity of water extract was more than 60%, and it was higher than the extracts. These results suggest that the 70% ethanol extract of Artemisia Argyi H. has a high rate of biological activities and can be useful to develop functional food ingredients.

A Study on the Methanation of Carbon Dioxide over Ni/Y-type Zeolites (Y형 제올라이트 담지 니켈촉매상에서 이산화탄소의 메탄화반응)

  • Lee, Kwan-Yong;Kim, Hyung-Wook;Kim, Geon-Joong;Ahn, Wha-Seung
    • Applied Chemistry for Engineering
    • /
    • v.4 no.2
    • /
    • pp.365-372
    • /
    • 1993
  • $CO_2$ methanation was performed over Ni supported on cation-exchanged Y zeolites under atmospheric pressure at $250{\sim}550^{\circ}C$ and $H_2/CO_2$ mole ratio of 4. Adsorption strength between carbon dioxide and nickel was found to be Influenced by the cation exchanged in the zeolite. TPD(Temperature-programmed desorption) results show that the adsorption strength decreases in the order of Ni/NaY>Ni/MaY>Ni/HY. TPSR(Temperature-programmed surface reaction) results indicate that enhanced methanation activity is obtained when the adsorption strength between carbon dioxide and nickel is stroing. As the reduction temperature increases, the methantion activity of the catalyst increase. From this result the larger size nickel particle seems advantageous for $CO_2$ methanation reaction. The maximum activity is obtained when nickel loading is 3.3wt%. Carbon monoxide is produced as a by-product throughout the reaction temperature range, and as the contact time increases, the selectivity to methane increases and the selectivity to carbon monoxide decreases steadily. Thus methane seems to be produced from $CO_2$ via CO as an intermediate species. In the temperature range of $410{\sim}450^{\circ}C$, the methane production rate is found to be dependent on the orders of 3.3~-0.5 and 1.4~3.6 with respect to $CO_2$ and $H_2$ partial pressures, respectively. This clearly shows that $CO_2$ and $H_2$ are competing for adsorption sites and as the reaction temperature increases, it becomes increasingly difficult for $H_2$ to be adsorbed on the catalyst surface.

  • PDF

Acer tegmentosum Maxim Prevents Bone Loss by Inhibiting Osteoclastogenesis and Promoting Osteoblast Mineralization in Ovariectomized Mice

  • Oh, Tae Woo;Park, Kwang-Il;Do, Hyun Ju;Kim, Kyungho;Yang, Hye Jin;Cho, Won Kyung;Ma, Jin Yeul
    • Natural Product Sciences
    • /
    • v.26 no.1
    • /
    • pp.83-89
    • /
    • 2020
  • Osteoporosis is a worldwide disease leading to significant economic and societal burdens globally. Osteoporosis is caused by unbalanced bone remodeling between the rate of osteoclast bone resorption and osteoblast bone formation. Acer tegmentosum Maxim (AT) is a traditional herbal medicine containing multiple biological activities such as anti-oxidant and anti-inflammatory purposes. However, its role in osteoporosis has not been fully studied. Therefore, we investigated whether AT has a potent inhibitory effect on osteoporosis and its mechanism through a systemic evaluation in ovariectomized (OVX) mice. OVX mice were orally administrated with the AT at doses of 50, 100, and 200 mg/kg for 10 weeks. Histological images and histomorphometry analyses were performed by H&E and Toluidine blue satin, and the expression levels of receptor activator for nuclear factor-kB ligand (RANKL), nuclear factor of activated T cells cytoplasm 1 (NFATc1), c-Fos, and matrix metalloproteinase 9 (MMP9) related to the osteoclast differentiation were investigated using immunohistochemical analysis. Administration of AT prevented bone loss and the alternations of osteoporotic bone parameters at the distinct regions of the distal femur and spongiosa region in OVX mice. Further, administration of AT increased periosteal bone formation in a dose-dependent manner. Meanwhile, AT inhibited not only the expression of NFATc1 and c-Fos, which are two major regulators of osteoclastogenesis but also reduced bone resorbed encoding expression of MMP9 and RANKL. Our results indicated that administration of AT prevented bone loss and the alternations of osteoporotic bone parameters at the distinct regions of the distal femur and spongiosa region in OVX mice. Also AT has the bone protective effect through the suppression of osteoclast and promotion of osteoblast, suggesting that it could be a preventive and therapeutic candidate for anti-osteoporosis.

The influence of entrepreneurial orientation and absorptive capacity on SME's NPD (기업가적 지향성과 흡수역량이 중소기업의 신제품개발에 미치는 영향)

  • Woo, Hyung-Rok;Kwon, Jung-Eon
    • Journal of Technology Innovation
    • /
    • v.21 no.2
    • /
    • pp.57-84
    • /
    • 2013
  • New product development(NPD) is imperative management activity for growth and survival of the firm. In the context of the small and medium-sized enterprises(SMEs), the firm became further dependent upon NPD with the increasing turbulence in environments. This research suggests the role of entrepreneurship orientation(EO) and absorptive capacity(ACAP) that affect the success rate of NPD in SMEs. Although each of them has been highlighted as critical resources in the aspect of the sustainable competitive advantage, the relationship and the effect between EO and ACAP have received scant attention. Based on the sample of 261 Korean SMEs, this study examines the direct/indirect effect of EO and ACAP on NPD performance. While innovativeness of EO has the direct effect on NPD performance, both risk-taking and proactiveness of EO show no significance. While realized ACAP has the positive influence on NPD performance, potential ACAP shows no significant influence. In addition, we found that the impact of innovativeness on NPD performance was being partially mediated by ACAP whereas the relationship between proactiveness and NPD performance being fully mediated by ACAP. These findings would provide generic insights that both exploration and exploitation regarding knowledge and resources in SMEs are necessary in order to increase NPD performance and two activities have to align with EO.

  • PDF

Anticancer Effects of Egg White Combined-Chalcanthite on NCI-H460 Tumor Regression Model (NCI-H460 폐암 유발 누드마우스 모형을 이용한 난담반의 항암 효과 연구)

  • Choi, Eun-A;Kim, Jung-Keun;Kim, Kyung-Soon;Choi, Jung-Eun;Cho, Chong-Kwan;Lee, Yeon-Weol;Yoo, Hwa-Seung
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.24 no.2
    • /
    • pp.272-277
    • /
    • 2010
  • This experimental study was performed to investigate the antitumor effect of Egg white combined-Chalcanthite (InSan 4, IS4) in xenografted nude mice with NCI-H460 human lung cancer cell. We cultured NCI-H460 cell lines and xenografted them on nude mice. These mice were divided into 3 groups; group with dose of 45 mg/kg IS4 orally, group with dose of 90 mg/kg IS4 orally, and the control group. They had been raised and treated for 28 days. We checked their body weight, tumor weight and volume twice a week, and their absolute organ weight, microhistological observation and biochemical blood analysis at the final day by sacrificing them. We also calculated their tumor inhibition rate (IR), mean survival time and percent increase in life span (% ILS). In this study, we observed that all of the IS4 treated mice have tumor regression, dosage-dependently, compared to the control group. Tumor weight and volume of high dose treated mice were smallest. IR increased in IS4 in a dose-dependent manner. Mean survival time and percent increase in life span (% ILS) in high-dose IS4 treatment group were the highest of the three groups. There was no significant difference in biochemical blood analysis, alanine phopsphatase (ALP), Calcium, creatinine (CRE), alanine transferase (ALT), and aspartate transaminase (AST) levels. The urea nitrogen (UN) level results significantly decreased by IS4 45 and 90 mg/kg (IS4 45 mg/kg, IS4 90 mg/kg, p<0.01). IS4 may have potential anti-tumor effect in a solid tumor induced by NCI-H460 without remarkable side effects.

A Study on the Estimation of Regional Myocardial Blood Flow in Experimental Canine Model with Coronary Thrombosis using Rb-82 Dynamic Myocardial Positron Emission Tomography (실험 개에서 Rb-82 심근 Dynamic PET 영상을 이용한 국소 심근 혈류 예측의 기본 모델 연구)

  • Kwark, Cheol-Eun;Lee, Dong-Soo;Kang, Keon-Wook;Hwang, Eun-Kyung;Jeong, Jae-Min;Chang, Kee-Hyun;Chung, June-Key;Lee, Myung-Chul;Seo, Joung-Don;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
    • /
    • v.29 no.1
    • /
    • pp.48-53
    • /
    • 1995
  • This study investigates a simple mathematical model for the quantitative estimation of regional myocardial blood flow in experimental canine coronary artery thrombosis using Rb-82 dynamic myocardial positron emission tomography. The coronary thrombosis was induced using the new catheter technique by narrowing the lumen of coronary vessel gradually, which finally led to partial obstruction of coronary artery. Ten Rb-82 dynamic myocardial PET scans were performed sequentially for each experiment using our 5, 10 and 20 second acquisition protocol, respectively, and three regions of interest were drawn on the transaxial slices, one on left ventricular chamber for input function and the other two on normal and decreased perfusion segments for the flow estimation in those regions. Single compartment model has been applied to the measured sets of regional PET data, and the rate constants of influx to myocardial tissue were calculated for regional myocardial flow estimates with the three parameter fits of raw data by the Levenberg-Marquardt method. The results showed that, (1) single compartment model suggested by Kety-Schmidt could be used for the simple estimation of regional myocardial blood flow, (2) the calculated regional myocardial blood flow estimates were dependent on the selection of input function, which reflected partial volume effect and left ventricular wall motion, and (3) mathematically fitted input and tissue time activity curves were more suitable than the direct application of the measured data in terms of convergence.

  • PDF

Stability Assessment of FKP System by NGII using Long-term Analysis of NTRIP Correction Signal (NTRIP 보정신호 분석을 통한 국토지리정보원 FKP NRTK 시스템 안정성 평가)

  • Kim, Min-Ho;Bae, Tae-Suk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.31 no.4
    • /
    • pp.321-329
    • /
    • 2013
  • Despite the advantage of unlimited access, there are insufficient studies for the accuracy and stability of FKP that blocks the spread of the system for various applications. Therefore, we performed a long-term analysis from continuous real-time positioning, and investigated the error characteristics dependent on the size and the surrounding environment. The FKP shows significant changes in the positioning accuracy at different times of day, where the accuracy during daytime is worse than that of nighttime. In addition, the size and deviation of FKP correction may change with the ionospheric conditions, and high correlation between ambiguity resolution rate and the deviation of correction was observed. The receivers continuously request the correction information in order to cope with sudden variability of ionosphere. On the other hand, the correction information was not received up to an hour in case of stable ionospheric condition. It is noteworthy that the outliers of FKP are clustered in their position with some biases. Since several meters of errors can be occurred for kinematic positioning with FKP, therefore, it is necessary to make appropriate preparation for real-time applications.

The Studies of Conductive and Non-Conductive Multi-Layer Depth Analysis by Radio Frequency Gas-Jet Boosted Glow Discharge Atomic Emission Spectrometry (Radio frequency gas-jet boosted 글로우 방전 원자 방출 분광법을 이용한 전도성 및 비 전도성의 다층 두께 분석에 관한 연구)

  • Cho, Won Bo;Lee, Seong Hun;Jeong, Jong Pil;Choi, Woo Chang;Borden, Stuart;Kim, Kyu Whan;Kim, Kyung Mi;Kim, Hyo Jin;Jeong, Seong Uk;Lee, Jung Ju
    • Analytical Science and Technology
    • /
    • v.15 no.3
    • /
    • pp.236-242
    • /
    • 2002
  • A method was investigated to determine the thickness of coating on steel sheet using rf glow discharge atomic emission spectrometer. The RF gas-jet boosted glow discharge has such salient feature as good pleasure stability and high sputtering efficiency that it was possible to determine the thickness of silicon resin film on zinc electroplated steel. The erosion speed variation is dependent on discharge power, gas flow rate and discharge pressure. therefore determine discharge condition to measure the thickness of coating on steels. The fundamental studies have been carried out to investigate an optimum condition for in-depth analysis and composition of zinc coating on steel. In this study, the calibration curve for thickness determination of silicon resin film was found to be linear in the range of $1000{\sim}3500mg/m^2$ film thickness. The developed rf gas-jet boosted glow discharge was applied to the analysis of zinc coating and silicon resin film on steel made by RIST.

Effect of Bisphenol A on Early Embryonic Development and the Expression of Glutathione S-transferase (GST) in the Sea Urchin (Hemicentrotus pulcherrimus) (말똥성게(Hemicentrotus pulcherrimus)의 초기배아 발생과 glutathione S-transferase (GST)의 발현에 대한 bisphenol A의 영향)

  • Hwang, Un-Ki;Kim, Dae-Han;Ryu, Hyang-Mi;Lee, Ju-Wook;Park, Seung-Yoon;Kang, Han Seung
    • Korean Journal of Environmental Biology
    • /
    • v.32 no.3
    • /
    • pp.234-242
    • /
    • 2014
  • In this study, gametotoxicity and embryotoxicity experiments using Hemicentrotus pulcherrimus were carried out to investigate the ecotoxicological effects of bisphenol A (BPA). We examined the effects of BPA on fertilization and normal embryogenesis at various concentrations (0, 300, 500, 800, 1000, and 1500 ppb). The results demonstrated that the fertilization rates were not changed. The normal embryogenesis rates were gradually decreased in a dose-dependent manner, and were significantly lowered following 800 ppb BPA treatment ($EC_{50}$=1056.1 ppb, 95% Cl=981.8~1163.9 ppb). The observed effective concentration and the lowest observed effective concentration of the normal embryogenesis rate were 500 ppb and 800 ppb, respectively. The embryos showed retarded development at each tested concentration, indicating the fact the embryonic development was delayed due to the increasing concentrations of BPA. Furthermore, we examined the expression of glutathione S-transferase (GST) mRNA at various concentrations of BPA in H. pulcherrimus. Interestingly, it was found that the expression level of GST mRNA was significantly increased in the experimental group exposed to BPA. Based on these results, we suggested that BPA at greater than 800 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and GST mRNA may be used as a biomarker for risk assessment of BPA contamination.

Rho-associated Kinase is Involved in Preimplantation Development and Embryonic Compaction in Pigs

  • Son, Myeong-Ju;Park, Jin-Mo;Min, Sung-Hun;Park, Hum-Dai;Koo, Deog-Bon
    • Journal of Embryo Transfer
    • /
    • v.25 no.2
    • /
    • pp.103-110
    • /
    • 2010
  • The first morphogenetic event of preimplantation development, compaction, was required efficient production of porcine embryos in vitro. Compaction of the porcine embryo, which takes place at post 4-cell stage, is dependent upon the adhesion molecule E-cadherin. The E-cadherin through ${\beta}$-catenin contributes to stable cell-cell adhesion. Rho-associated kinase (ROCK) signaling was found to support the integrity of E-cadherin based cell contacts. In this study, we traced the effects of ROCK-1 on early embryonic development and structural integrity of blastocysts in pigs. Then, in order to gain new insights into the process of compaction, we also examined whether ROCK-1 signaling is involved in the regulation of the compaction mediated by E-cadherin of cellular adhesion molecules. As a result, real-time RT-PCR analysis showed that the expression of ROCK-1 mRNA was presented throughout porcine preimplantation stages, but not expressed as consistent levels. Thus, we investigated the blastocyst formation of porcine embryos treated with LPA and Y27632. Blastocysts formation and their qualities in LPA treated group increased significantly compared to those in the Y27632-treated group (p < 0.05). Then, to determine whether ROCK-1 associates embryonic compaction, we explored the effect of activator and/or inhibitor of ROCK-1 on compaction of embryos in pigs. The rate of compacted morula in LPA treated group was increased compared to that in the Y27632-treated group (39.7 vs 12.0%). Furthermore, we investigated the localization and expression pattern of E-cadherin at 4-cell stage porcine embryos in both LPA- and Y27632-treated groups by immunocytochemical analysis and Western blot analysis. The expression of E-cadherin was increased in LPA-treated group compared to that in the Y27632-treated group. The localization of E-cadherin in LPA-treated group was enriched in part of blastomere contacts compared to that Y27632-treated group. ROCK-1 as a crucial mediator of embryo compaction may plays an important role in regulating compaction through E-cadherin of the cell adhesion during the porcine preimplantation embryo. We concluded that ROCK-1 gene may affect the developmental potential of porcine blastocysts through regulating embryonic compaction.