• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.1-9
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• 1997

This study was conducted to efficiently separate the Ig from Korean native cattle colostrum and to utilize them as an immunogen for the production of antibodies aginst rabbit. The results obtained were as follows : 1. About 84% of Ig G could be separated from Korean native cattle colostrum by·gel filtration using Superose 12 column on HPLC. The separation profile of Korean native cattle colostral immunoglobulin was similar that of Holstein colostral Ig. 2. Separation of Korean native cattle colostral Ig by anion exchange chromatography using Mono Q column on HPLC was poor resolution chromatographic pattern. 3. Hi-Trap Protein G column showed better results than the Protein A Sepharose CL-4B column in the Ig G binding capacity from Korean native cattle colostral Ig. 4. Protein G Sepharose Fast Flow system resulted in higher Ig g binding capacity as the industrial size scale-up approach. 5. Sufficient titer reaction of antibody to Korean native cattle colostral Ig G was confirmed by ELISA.

• Progress in Medical Physics
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• v.17 no.2
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• pp.96-104
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• 2006

Experiments from several groups Including ours have demonstrated that $Ca^{2+}$ can enhance the inactivation of N-type calcium channels. However, it is not clear if this effect can be ascribed to a 'classic' $Ca^{2+}$-dependent inactivation (CDI) mechanism. One method that has been used to demonstrate CDI of L-type calcium channels is to alter the intracellular and extracellular concentration of $Ca^{2+}$. In this paper we replaced the external divalent cation to monovalent ion ($MA^+$) to test CDI. In the previous paper, we could separate fast (${\tau}{\sim}150ms$) and slow (${\tau}{\sim}2,500ms$) components of inactivation in both $Ba^{2+}$ and $Ca^{2+}$ using 5-sec voltage step. Lowering the external divalent cation concentration to zero abolished fast inactivation with relatively little effect on slow inactivation. Slow inactivation ${\tau}$ correspond very well with provided the $MA^+$ data is shifted 10 mV hyperpolarized and slow inactivation ${\tau}$ decreases with depolarization voltage in both $MA^+\;and\;Ba^{2+}$, which consistent with a classical voltage dependent inactivation (VDI) mechanism. These results combined with those of our previous paper lead us to hypothesize that external divalent cations are required to produce fast N-channel inactivation and this divalent cation-dependent inactivation is a different mechanism from classic CDI or VDI.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.781-785
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• 2005

A fast and reliable method for the selective separation and preconcentration of $Cu^{2+}$ ions using homogeneous liquid-liquid extraction was developed. A new $\alpha$-dioxime derivative (2H-1,4-benzothioazine-2,3(4H)dionedioxime, Dioxime I) was synthesized and investigated as a suitable selective complexing ligand for $Cu^{2+}$ ions. Zonyl FSA (FSA) was applied as a phase-separator agent under the slightly acidic pH conditions. Under the optimal experimental conditions ([FSA] = 3.2% w/v, [THF] = 19.5% v/v, [Dioxime I] = 1.9 ${\times}\;10^{-3}$ M, and pH = 4.7), 10 ${\mu}g\;of\;Cu^{2+}$ in 5.2 mL aqueous phase could be extracted quantitatively into 80 $\mu$L of the sedimented phase. The maximum concentration factor was 65-fold. The limit of detection of the proposed method was 0.005 ng $mL^{-1}$. The reproducibility of the proposed method, on the 10 replicate measurements, was 1.3%. The influence of the pH, type and volume of the water-miscible organic solvent, concentration of FSA, concentration of the complexing ligand and the effect of different diverse ions on the extraction and determination of $Cu^{2+}$ ions were investigated. The proposed method was applied to the extraction and determination of $Cu^{2+}$ ion in different synthetic and natural water samples.

• Textile Coloration and Finishing
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• v.27 no.1
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• pp.1-10
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• 2015

The aim of the current study is to identify the dimerization and decomposition kinetics of the F-$D_M$ type. The regeneration of F-VS from $F_iF_j-D_M$ or the reversibility of the dimerizations were investigated. The order of real rate constants of the dimerization('$K_D{^{ij}}$) would seem to be similar to that of rate constants of a dimerization($K_D{^{ij}}$) for VS dyes at a given pH because of the constancy of the equilibrium constants($K_a{^j}$-value). The reverse reactions of the $D_M$ types are appeared to occur in two steps, the deprotonation of ${\alpha}$-carbon of the $D_M$ types and disproportionation. The ratio of the decomposition of the $D_M$ type to F-Hy and F-VS appears to be related with the ratio of $K_i/K_j$. Similarities were also found among various other reactions, including homo- and mixed dimerization. VS dyes undergoing fast hydrolysis have difficulty in forming a dimer. The higher the reactivity with cellulose or hydroxide ion, the smaller the dimerization. The easiness of the dimerization was thus found to be inversely proportional to the rate of hydrolysis.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.478-484
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• 1996

Recombinant human epidermal growth factor (rhEGF) was produced by E. coli BL21 harboring a plasmid pYHB101. The maximum production was 68.7 mg/l when the E. coli strain was cultured at 25$\circ$C for 48 hours in the modified MBL medium containing 10 g/l glucose with 1 mM IPTG induction at 2 hours after inoculation. The rhEGF was purified upto 267 folds by Amberlite XAD- 7 chromatography, ultrafiltration, and DEAE Sepharose fast flow ion exchange chromatography with an overall yield of 66.6%. The purified rhEGF was further separated into two fractions by HPLC. The N-terminal amino acid sequence of the second fraction was Asn-Ser-Asp-Ser-Glu-Cys-Pro-Leu-Ser-His. The effect of rhEGF on the DNA synthesis was examined using in vitro biological assay based on the incorporation of 5'-bromo-2'- deoxy-uridine (BrdU). The purified rhEGF shows no difference with natural human epidermal growth factor (nhEGF) in N-terminal amino acids residues and biological activity. From the results, we concluded that rhEGF produced from E. coli harboring the plasmid pYHB101 was apparently the same as nhEGF.

• Journal of Pharmaceutical Investigation
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• v.18 no.3
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• pp.125-131
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• 1988

This study was undertaken to investigate the proteolytic enzyme from Neungee mushroom [Sarcodon aspratus (Berk) S. Ito]. The proteolytic activity of Neungee was higher than other several edible mushrooms under various pHs. The potency of proteolytic enzyme of Neungee was same as the digestive drugs containing protease. So the proteolytic activity of the enzyme was increased in neutral or weak alkaline pH, whose characteristics would be alkaline protease. The specific activity of the purified enzyme obtained by using Tris acryl CM-cellulose ion exchange increased 20 times as compared with that of the crude extract. The proteolytic enzyme was stable at room temperature, but decomposition was fast when incubated at higher temperature more than $40^{\circ}C$. The half life of the enzyme was longest in neutral pH and rate constant was increased in acidic or alkaline solution.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.28.2-28.2
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• 2011

Resistance random access memory (ReRAM) is a promising candidate for next-generation nonvolatile memory because of its advantageous qualities such as simple structure, superior scalability, fast switching speed, low-power operation, and nondestructive readout. We investigated the resistive switching behavior of tantalum oxide that has been widely used in dynamic random access memories (DRAM) in the present semiconductor industry. As a result, it possesses full compatibility with the entrenched complementary metal-oxide-semiconductor processes. According to previous studies, TiN is a good oxygen reservoir. The TiN top electrode possesses the specific properties to control and modulate oxygen ion reproductively, which results in excellent resistive switching characteristics. This study presents fully room temperature fabricated the TiN/$TaO_x$/Pt devices and their electrical properties for nonvolatile memory application. In addition, we investigated the TiN electrode dependence of the electrical properties in $TaO_x$ memory devices. The devices exhibited a low operation voltage of 0.6 V as well as good endurance up to $10^5$ cycles. Moreover, the benefits of high devise yield multilevel storage possibility make them promising in the next generation nonvolatile memory applications.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.63-68
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• 2014

For a nanoscale Cu/low-k wafer, inter-layer dielectric (ILD) and metal layers peelings, cracks, chipping, and delamination are the most common dicing defects by traditional diamond blade saw process. Sidewall void in sawing street is one of the key factors to bring about cracks and chipping. The aim of this research is to evaluate laser grooving & mechanical sawing parameters to eliminate sidewall void and avoid top-side chipping as well as peeling. An ultra-fast pico-second (ps) laser is applied to groove/singulate the 28-nanometer node wafer with Cu/low-k dielectric. A series of comprehensive parametric study on the recipes of input laser power, repetition rate, grooving speed, defocus amount and street index has been conducted to improve the quality of dicing process. The effects of the laser kerf geometry, grooving edge quality and defects are evaluated by using scanning electron microscopy (SEM) and focused ion beam (FIB). Experimental results have shown that the laser grooving technique is capable to improve the quality and yield issues on Cu/low-k wafer dicing process.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.297-300
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• 2019

In countries with FMD vaccination, as in Korea, typical clinical signs do not appear, and even in FMD positive cases, it is difficult to isolate the FMDV or obtain whole genome sequence. To overcome this problem, more rapid and simple NGS system is required to control FMD in Korea. FMDV (O/Boeun/ SKR/2017) RNA was extracted and sequenced using Ion Torrent's bench-top sequencer with amplicon panel with optimized bioinformatics pipelines. The whole genome sequencing of raw data generated data of 1,839,864 (mean read length 283 bp) reads comprising a total of 521,641,058 (≥Q20 475,327,721). Compared with FMDV (GenBank accession No. MG983730), the FMDV sequences in this study showed 99.83% nucleotide identity. Further study is needed to identify these differences. In this study, fast and robust methods for benchtop next generation sequencing (NGS) system was developed for analysis of Foot-and-mouth disease virus (FMDV) whole genome sequences.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.5
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• pp.93-102
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• 1996

Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.