• 한국균학회지
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• 제19권3호
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• pp.220-225
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• 1991

1. 표고버섯 중 정제된 ATPase는 $Fe^{3+},\;Fe^{2+},\;Cd^{2+},\;Mg^{2+},\;K^{+}$ 및 $Co^{2+}$ 이온에 의하여 활성화 되었으나 $Zn^{2+},\;Ca^{2+},\;Cu^{2+}$ 및 $Ni^{2+}$ 이온에 의하여는 그 활성도가 억제되었다. 2. 5 mM $Fe^{3+}$, 10 mM $Fe^{2+}$, 1 mM $Cd^{2+}$, 5 mM $Mg^{2+}$, 5 mM $K^{+}$ 및 5 mM $Co^{2+}$이온은 이효소의 활성을 각각 130, 65, 65, 68, 105 및 23% 증가시켰다. 3.10 mM $Zn^{2+}$, 10 mM $Ca^{2+}$, 0.5 mM $Cu^{2+}$ 그리고 10 mM $Ni^{2+}$ 이온은 이효소의 활성을 각각 18, 19, 27% 그리고 30%의 억제효과를 보였다. 4. 10 mM ${Co_3}^{2-}$, 20 mM $CN^{-}$, 20 mM ${CH_3COO}^{-}$ 그리고 20 mM ${NO_3}^{-}$의 음이온은 이효소의 활성을각각 98, 95, 70% 그리고 50%를 억제시켰으나,${SO_4}^{2-}$ 이온은 농도증가에 따라 활성화 되었고, 20 mM 용액에서 21%로 활성도 증가의 최대치를 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.41-44
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• 2003

As the device feature size is reduced to the deep sub-micron regime, the chemical mechanical polishing (CMP) technology is widely recognized as the most promising method to achieve the global planarization of the multilevel interconnection for ULSI applications. However, cost of ownership (COO) and cost of consumables (COC) were relatively increased because of expensive slurry. In this paper, the effects of different slurry composition on the oxide CMP characteristics were investigated to obtain the higher removal rate and lower non-uniformity. We prepared the various kinds of slurry. In order to save the costs of slurry, the original slurry was diluted by de-ionized water (DIW). And then, alunima abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry.

• Current Optics and Photonics
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• 제6권3호
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• pp.337-343
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• 2022

Microfluidic chips are new devices that can manipulate liquids at the micrometer level, and terahertz (THz) time-domain spectroscopy has good applicability in biochemical detection. The combination of these two technologies can shorten the distance between sample and THz wave, reduce THz wave absorption by water, and more effectively analyze the kinetics of biochemical reactions in aqueous solutions. This study investigates the effects of different external magnetic field intensities on the THz transmission characteristics of deionized water, CuSO₄, CuCl₂, (CH₃COO)₂Cu, Na₂SO₄, NaCl, and CH₃COONa; the THz spectral intensity of the sample solutions decrease with increasing intensity of the applied magnetic field. Analysis shows that the magnetic field leads to a change in the dipole moment of water molecules in water and electrolyte solutions, which enhances not only the hydrogen-bond networking ability of water but also the hydration around ions in electrolyte solutions, increasing the number of hydrogen bonds. Increasing the intensity of this magnetic field further promotes the hydrogen-bond association between water molecules, weakening the THz transmission intensity of the solution.

• Bulletin of the Korean Chemical Society
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• 제24권2호
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• pp.193-196
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• 2003

Nucleophilic addition reactions of benzylamines $(XC_6H_4CH_2NH_2)$ to benzylidene Meldrum's acids (BMA; $YC_6H_4CH=C(COO)_2C(CH_3)_2$) have been investigated in acetonitrile at 20.0 ℃. The rates of addition are greatly enhanced due to the abnormally high acidity of Meldrum's acid. The magnitudes of the Hammett $({\rho}_X\;and\;{\rho}_Y)$ and Bronsted $({\rho}_X$)$ coefficients are rather small suggesting an early transition state. The sign and magnitude of the cross-interaction constant, ${\rho}_{XY}$ (= -0.33), and kinetic isotope effects $(k_H/k_D\;{\stackrel}{~}{=}\;1.5-1.7)$ involving deuterated benzylamine nucleophilies $(XC_6H_4CH_2ND_2)$ are indicative of hydrogen-bonded cyclic transition state. The activation parameters, ${\Delta}H^{\neq}\;{\stackrel}{~}{=}\;4\;kcal\;mol^{-1}\;and\;{\Delta}S^{\neq}\;{\stackrel}{~}{=}\;-37\;e.u.$, are also in line with the proposed mechanism.

• 한국정밀공학회지
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• 제22권1호
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• pp.199-206
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• 2005

Mask manufacturing is a high COC and COO process in developing of semiconductor devices because of mask production tool with high resolution. Direct writing has been thought to be the one of the patterning method to cope with development or small-lot production of the device. This study consists two categories. One is the additional process of the direct and maskless patterning generation using SLA for easy and convenient application and the other is a removal process using wet-etching process. In this study, cured status of epoxy pattern is most important parameter because of the beer-lambert law according to the diffusion of UV light. In order to improve the contact force between patterns and substrate, prime process was performed and to remove the semi-cured resin which makes a bad effects to the pattern, spin cleaning process using TPM was also performed. At a removal process, contact force between photo-curable resin as an etching mask and Si wafer is important parameter.

• 산경연구논집
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• 제9권1호
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• pp.39-49
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• 2018

Purpose - This present aims to analyze the effect of export modes on initial export amount and time to export by selecting export modes among various success strategies and factors. Research design, data, and methodology - It surveyed 980 small and mid-sized venture enterprises across Korea. The export modes and its impact on exports through frequency analysis and cross analysis, and validated through a PPML(regression analysis applied the enterprise growth model) analysis. Results - Five export modes were investigated : direct export, indirect export, transfer from direct export to indirect export, transfer from direct export to indirect export, and parallel export to indirect export. It was found that SMVEs that exported directly from establishment to initial export had the shortest period, and also had the highest export price Conclusions - From a marketing point of view, it took an average of 1.6 years to switch from export directly to indirect export or directly export, and the reason for the export modes conversion was to supplement export specialists and improve export competitiveness. And the export amount and time period that SMVEs establishes and export is a significant factor in export success strategy and there has been few prior study in export modes.

• Macromolecular Research
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• 제17권5호
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• pp.332-338
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• 2009

Rheological behavior of natural hydrogel produced from seeds of three Salvia spp. (S. miltiorrhiza (SM), S. sclarea (SS), S. viridis (SV)) was investigated by using a Rheometer equipped with a cone and plate geometry measuring system under never-dried condition. Different chemical contents of such hydrogels give significant effects on their rheological properties. Because of incomplete penetration of water inside the hydrogels after drying before-dried hydrogels were used for rheological analysis. To know molecular interactions which predominated in the gel formation, some constituents were externally added to the 1.0% (w/w) hydrogel. Addition of urea to disrupt hydrogen bonds reduced 3.4-67% viscosity of the untreated hydrogels and changed viscoelastic properties from gel to liquid-like behavior. Neutral salts added to the hydrogel solution at 0.1 M also lowered the viscosity in a manner related with increase in size of cations and temperature. Changing from gel state to liquid-like state was also easily confirmed by oscillation measurement (storage, G', and loss, G", modulii) typically observed in the cases of potassium sulfate and potassium thiocyanate. Influence of pH variation on the viscosity explained that weak alkaline condition (pH 8-9) creates a higher resistance to flow due to increasingly electrostatic repulsions between negative charges ($COO^-$) Importance of calcium bridges was also demonstrated by recovery of viscosity of the hydrogels by addition of calcium after acidification. The summarized results indicate that electrostatic repulsion is a major contributor for production of hydrogel structure.

• Biomolecules & Therapeutics
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• 제11권2호
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• pp.85-90
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• 2003

Microtubule-binding molecules have been developed as anti-cancer agents to overcome the toxicities of current chemotherapeutics and also have potential for use as anti-angiogenic agents. In this work, we examined the effect of novel triazine compounds, Tubulyzines (microTUBUle LYsing triaZINE), derived from the orthogonal synthesis of a triazine library, on endothelial progenitor cell differentiation. When mononuclear cells isolated from human cord blood were cultured on fibronectin-coated plates for 7 days, all the Tubulyzine compounds A, B, and C (TA, TB, and TC) tested decreased the number of adherent cells in a dose-dependent manner in a coo. centration ranges of 2-5 to $80\mu\textrm{M}$. TA ($IC_{50}$=$20\mu\textrm{M}$) showed slightly more potent activity than TB and TC. Adherent cells treated with TA also exhibited a lower level of ability to ac-LDL uptake, with low ratios of positive cells out of total adherent cells, in a dose-dependent manner and weak expression of endothelial lineage markers, KDR, CD31, and vWF at $20\mu\textrm{M}$. Therefore, these results suggest that tubulyzine A (TA) can be effectively used for the inhibition of new vessel growth by inhibiting differentiation of endothelial progenitor cells.

• 유통과학연구
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• 제16권1호
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• pp.59-71
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• 2018

Purpose - Recognizing the importance of small and medium enterprises and venture enterprises for the domestic economy, the purpose of the present study is to select factor termed export modes from among various export success strategies and factors that can help those enterprises secure export competitiveness in the world market to analyze the effects of export modes on the amounts of exports and periods until export after the foundation of those enterprises. Research design, data, and methodology - A structured questionnaire was used as a tool to derive the purpose of the study, and a questionnaire survey was conducted using a mobile survey technique that facilitated the distribution of questionnaire sheets and the collection of results. The main methodology used is crossover analysis, and the regression analysis technique was applied to verify the study results derived, thereby securing the reliability and validity of the final results derived. Results - Small and medium venture enterprises with shorter periods of time until the first export success after establishment adopted direct export modes more frequently, and those enterprises with larger amounts of the first export after establishment adopted direct export modes more frequently. The results of quantitative analysis, indicating that 66.1% of those enterprises with an export amount exceeding one billion won adopted direct export modes, can be said to support the foregoing. The crossover analysis results derived as such were reanalyzed using the PPML regression analysis technique to quantitatively identify that the amounts of the first export of enterprises that adopted direct export modes were larger than those of enterprises that adopted indirect export modes by 120%. Conclusions - The present study implies differentiated values in three aspects. First, the present study investigated and presented the export success factors and strategies of small and medium venture enterprises in a total of 14 countries in the Asian region, European region, North American region, African region, and South American region. Second, it intensively investigated five export modes to identify and verify that they were affecting the export success of small and medium venture enterprises. Third, based on the results of the investigation, the present study presented two marketing implications in the pragmatic aspect.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6773-6779
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• 2014

Background: Nanotechnology opens new applications in many fields including medicine. Among all metallic nanoparticles, silver nanoparticles (silver NPS) have proved to be the most effective against a large variety of organisms including toxic cyanobacteria. Materials and Methods: Silver NPs were biosynthesized in vivo with different alga species namely, Spirulina piatensis, Chlorella vulgaris and Scenedesmus oh/iquus following two scenarios. First: by suspending a thoroughly washed algae biomass in 1 mM aqueous $AgN0_3$ solution. Second: by culturing them individually in culture media containing the same concentration of $AgN0_3$. Silver NPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FfIR) spectroscopy. The biosynthesized silver NPs were tested for cytotoxic activity against a cancer promoter cyanobacteruim Microcystis aeruginosa, considering effects on cell viability and chlorophyll content. Results: The surface plasmon band indicated the biosynthesis of silver NPs at ~400 nm. Transmission electron microscopy (TEM) revealed that the silver NPs had a mean average size below 100 nm. Energy-dispersive analysis X-ray (EDX) spectra confirmed the presence of silver element. FfIR spectral analyses suggested that proteins and or polysaccharides may be responsible for the biosynthesis of silver NPs and (-COO-) of carboxylate ions is responsible for stabilizing them. The toxic potentialities ofthe biosynthesized silver NPs against the cancer promoter cyanobacterium, Microcystis aeruginosa showed high reduction in viable cells count and the total chlorophyll content. Conclusions: The potential activity of the biosynthesized silver NPs from the studied algae species against Microcystis aernginosa cells is expected to be mainly mediated by the release of silver ions (Ag+) from the particle surface and bioactive compounds as indicated by FfIR analysis.