• Title/Summary/Keyword: Bio-nano

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Effects of EGF and PAF on the Hatching and Implantation of Peri-implantation Stage Embryos

  • Cheon, Yong-Pil
    • Development and Reproduction
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    • v.14 no.1
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    • pp.27-34
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    • 2010
  • A fertilized oocyte can get the competence for implantation through cleavage and stage-specific gene expression. These are under the control of autonomous and exogenous regulators including physiological culture condition. Endogenous and exogenous growth factors are considered as critical regulators of cleaving embryos during travel the oviduct and uterus. In this study, an effort was made to evaluate comprehensively the quality of embryos for implantation, grown in media enriched with EGF and PAF. The study evaluated developmental rates on given time, blastulation and hatching rates, and adhesion rates. Developmental rates of blastocyst to the hatching stage were significantly high in PAF treated group compared to the control in a dose-dependent manner but not in EGF group. Implantation rates were significantly high both PAF and EGF in a dose-dependent manner. H7, a PKC inhibitor, blocked the process of hatching of the blastocysts but combined treatment of EGF and PAF enhanced the hatching and implantation of blastocsyts. Based on these results it is suggested that EGF and PAF support acquirement of implantation competence at blastocyst stage through a PKC pathway.

Effects of dietary supplementation of high-dose folic acid on biomarkers of methylating reaction in vitamin $B_{12}$-deficient rats

  • Min, Hye-Sun
    • Nutrition Research and Practice
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    • v.3 no.2
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    • pp.122-127
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    • 2009
  • Folate is generally considered as a safe water-soluble vitamin for supplementation. However, we do not have enough information to confirm the potential effects and safety of folate supplementation and the interaction with vitamin $B_{12}$ deficiency. It has been hypothesized that a greater methyl group supply could lead to compensation for vitamin $B_{12}$ deficiency. On this basis, the present study was conducted to examine the effects of high-dose folic acid (FA) supplementation on biomarkers involved in the methionine cycle in vitamin $B_{12}$-deficient rats. Sprague-Dawley rats were fed diets containing either 0 or $100{\mu}g$ (daily dietary requirement) vitamin $B_{12}/kg$ diet with either 2 mg (daily dietary requirement) or 100 mg FA/kg diet for six weeks. Vitamin $B_{12}$-deficiency resulted in increased plasma homocysteine (p<0.01), which was normalized by dietary supplementation of high-dose FA (p<0.01). However, FA supplementation and vitamin $B_{12}$ deficiency did not alter hepatic and brain S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) concentrations and hepatic DNA methylation. These results indicated that supplementation of high-dose FA improved homocysteinemia in vitamin $B_{12}$-deficiency but did not change SAM and SAH, the main biomarkers of methylating reaction.

Synthesis of [1,2,4]-Triazole Derivatives and Their Anticancer Activities ([1,2,4]-Triazole 유도체의 합성 및 항암활성)

  • Lee, So-Ha;Kim, Jun-Suck;Jeon, Jae-Ho;Lee, Sook-Ja
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.2
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    • pp.109-116
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    • 2007
  • 2-Chlorobenzoyl hydrazine refluxed with benzoyl isothiocyanate and phenyl isothiocyanate in ethanol for 3 hours to give benzamide derivative (1) and anilinederivative (2) on yield of 71%and 95%, respectively. Benzamide derivative (1) reacted with ethanolic sodium hydroxide on reflux to afford cyclization product (3), followed by general substitution reaction of two steps to give acetamide (5), and derivatived acetamides 7a-7k, while aniline derivative (2) reacted with ethanolic sodium hydroxide on reflux to afford another cyclization product (4). Thiol (4) reacted with N-phenyl chloroacetamide in the presence of potassim carbonate to give acetamide derivative (6). Compounds 1-7kwere evaluated for their growth inhibition against five cancer cell lines, including human lung carcinoma (A-549), human prostate cancer (DU145), human colon adenocarcinoma (HT-29), human malignant melanoma (SK-MEL-2) and human ovary malignant ascites (SK-OV-3) with sulforhodamine B (SRB) assay. All compounds (1-7k) showed low inhibition activities under 50% on 100M concentration.

Biological Assay of Mercury and Cadmium Ions Using DNA Immobilized on a Nanotube Paste Electrodes

  • Ly, Suw-Young;Lee, Chang-Hyun;Jung, Hong-Rak;Park, Kwang-Ho;Park, Yong-Keun;Suk, Hong-Woo
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.2
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    • pp.302-310
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    • 2012
  • Bio assay of mercury and cadmium ions were searched using voltammetric analysis using DNA doped carbon nanotube paste electrodes (DCP). The square-wave stripping voltammetryic optimized results indicated working ranges of 1-10.0 $ngL^{-1}$ and 20-100 $ugL^{-1}$, Hg(II) Cd(II) within an accumulation time of 120 seconds, in 0.1-M phosphate buffer solutions of pH 6.3. The relative standard deviations of 5 $ngL^{-1}$ Hg(II) and Cd(II) that observed were 0.14 and 0.22% (n=12), respectively, using optimum conditions. The low detection limit (S/N) was pegged at 0.1 $ngL^{-1}$ ($4.9{\times}10^{-11}M$) Hg(II) and 0.2 $ngL^{-1}$ ($1.77{\times}10^{-10}M$) Cd(II). The developed methods can be applied to assays in biological fish kidneys and water samples.

Characterization of Low-temperature SU-8 Negative Photoresist Processing for MEMS Applications

  • May Gary S.;Han, Seung-Soo;Hong, Sang-Jeen
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.4
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    • pp.135-139
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    • 2005
  • In this paper, negative SU-8 photoresist processed at low temperature is characterized in terms of delamination. Based on a $3^3$ factorial designed experiment, 27 samples are fabricated, and the degree of delamination is measured for each. In addition, nine samples are fabricated for the purpose of verification. Employing the. neural network modeling technique, a process model is established, and response surfaces are generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. From the response surfaces generated, two significant parameters associated with delamination are identified, and their effects on delamination are analyzed. Higher PEB temperature at a fixed PEB time results in a greater degree of delamination. In addition, a higher dose of exposure energy lowers the temperature at which the delamination begins and also results in a larger degree of delamination. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

Effects of thermal boundary conditions and microgravity environments on physical vapor transport of $Hg_2Cl_2-Xe$ system

  • Kim, Geug-Tae;Kwon, Moo-Hyun;Lee, Kyong-Hwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.4
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    • pp.172-183
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    • 2009
  • For the effects of the nonlinear temperature profiles and reduced-gravity conditions we conduct a two-dimensional numerical modeling and simulations on the physical vapor transport processes of $Hg_2Cl_2-Xe$ system in the horizontal orientation position. Our results reveal that: (1) A decrease in aspect ratio from 5 to 2 leads to an increasingly nonuniform interfacial distribution and enhances the growth rate by one-order magnitude for normal gravity and linear wall temperature conditions. (2) Increasing the molecular weight of component B, Xenon results in a reduction in the effect of solutal convection. (3) The effect of aspect ratio affects the interfacial growth rates significantly under normal gravity condition rather than under reduced gravitational environments. (4) The transition from the convection-dominated regime to the diffusion-dominated regime ranges arises near at 0.1g$_0$ for operation conditions under consideration in this study.

Synthesis and reactivity over molybdenum carbide crystallites

  • Choi, Jeong-Gil
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.2
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    • pp.74-79
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    • 2010
  • The synthesis and reactivities of molybdenum carbide crystallites were examined in this study. Especially, the effect of synthesis conditions were scrutinized on the preparation of molybdenum carbide crystallites. In order to perform this purpose, various characterization techniques such as BET surface area and oxygen uptake measurements were employed for the synthesized molybdenum carbide crystallites. First of all, the molybdenum carbide crystallites were synthesized using molybdenum oxide crystallites and methane gas or methane-hydrogen mixture. The experimental results showed that BET surface areas ranged from $7.4m^2/g$ to $31m^2/g$ and oxygen uptake values varied from $8.1{\mu}mol/g$ to $24.3{\mu}mol/g$. The Mo compounds were found to be active for ammonia decomposition reaction. Even though there are some molybdenum carbide crystallites that were exceeded by Pt/$Al_2O_3$ crystallite, the steady state reactivities for other molybdenum carbide crystallites were comparable to or even higher than that determined for the Pt/$Al_2O_3$ crystallite. These results implied that molybdenum carbide crystallites could be one of the promising crystallites that might be substitutes for Pt-like noble metal crystallites in the petroleum processes.

Effects of convection on physical vapor transport of Hg2Cl2 in the presence of Kr - Part I: under microgravity environments

  • Lee, Yong Keun;Kim, Geug-Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.1
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    • pp.20-26
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    • 2013
  • Special attention in the role of convection in vapor crystal growth has been paid since some single crystals under microgravity environments less than 1 $g_0$ exhibits a diffusive-convection mode and much uniformity in front of the crystal regions than a normal gravity acceleration of 1 $g_0$. The total molar fluxes show asymmetrical patterns in interfacial distribution, which indicates the occurrence of either one single or more than one convective cell. As the gravitational level decreases form 1 $g_0$ down to $1.0{\times}10^{-4}\;g_0$, the intensity of convection, indicative of the maximum molar fluxes, is reduced significantly for ${\Delta}T=30K$ and 90 K. The total molar fluxes decay first order exponentially with the partial pressure of component B, PB (Torr) for 20 Torr ${\leq}PB{\leq}$ 300 Torr, and two gravity accelerations of $g_y=1\;g_0$ and 0.1 $g_0$.

Leaves of Raphanus sativus L. Shows Anti-Inflammatory Activity in LPS-Stimulated Macrophages via Suppression of COX-2 and iNOS Expression.

  • Park, Hye-Jin;Song, Minjung
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.50-55
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    • 2017
  • Raphanus sativus L. (RS) is a cruciferous vegetable that is widely consumed in Korea. The anticancer activity of leaves of RS (RSL) extract has been investigated; however, no studies focused on its anti-inflammatory effects. Therefore, the aim of the current study was to evaluate the anti-inflammatory effects of RSL extract. In brief, RSL powder was fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and water-soluble fractions. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells were treated with each fraction for initial screening. It was found that the chloroform fraction significantly inhibited nitric oxide release in LPS-stimulated RAW264.7 cells with a half maximal inhibitory concentration value of $196{\mu}g/mL$. In addition, the mRNA and protein expression levels of inducible nitric oxide synthase, measured using reverse transcriptase-polymerase chain reaction and western blotting, respectively, were reduced in a concentration-dependent manner. Moreover, the inflammatory cyclooxygenase-2 enzyme expression decreased. Furthermore, the expression of nuclear factor-kappa B ($NF-{\kappa}B$), the key regulator of the transcriptional activation of the inflammatory cytokine genes, was reduced by the RSL chloroform fraction. Therefore, the results of our study suggest that RSL exhibits anti-inflammatory effects in LPS-stimulated macrophages via $NF-{\kappa}B$ inactivation.

Effect of aspect ratio on solutally buoyancy-driven convection in mercurous chloride $(Hg_2Cl_2)$ crystal growth processes

  • Kim, Geug-Tae;Lee, Kyoung-Hwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.4
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    • pp.149-156
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    • 2006
  • For an aspect ratio (transport length-to-width) of 5, Pr = 2.89, Le = 0.018, Pe = 2.29, Cv = 1.11, $P_B$=40 Torr, solutally buoyancy-driven convection $(Gr_s=3.03{\times}10^5)$ due to the disparity in the molecular weights of the component A $(Hg_2Cl_2)$ and B (He) is stronger than thermally buoyancy-driven convection $(Cr_t=1.66{\times}10^4)$. The crystal growth rate is decreased exponentially for $2.5\;{\leq}\;Ar\;{\leq}\;5$, with (1) the linear temperature profile and a fixed temperature difference, (2) the imposed thermal profile, a fixed crystal region and varied temperature difference. This is related to the finding that the effects of side walls tend to stabilize convection in the growth reactor. But, with the imposed thermal profile, a fixed source region and varied temperature difference, the rate is increased far $2\;{\leq}\;Ar\;{\leq}\;3$, and remains nearly unchanged for $3\;{\leq}\;Ar\;{\leq}\;5$.