• Food Science and Biotechnology
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• v.14 no.4
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• pp.479-486
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• 2005

Arabinoxylan, a complex polysaccharide in cereal cell walls, has recently received research attention as a biological response modifier. The immunomodulating effect of arabinoxylans from rice bran (AXrb) was studied using a combined process of extrusion and commercial hemicellulase treatment in order to elucidate the augmentation mechanism of cell-mediated immunity in vitro. The cytotoxicity of mouse spleen lymphocytes against YAC-1 tumor cells was significantly enhanced by treatment with AXrb at $10-100\;{\mu}g/mL$. In an attempt to investigate the mechanism by which AXrb enhance NK cytotoxicity, we examined the effect of AXrb on cytokine production by spleen lymphocytes. Culture supernatants of the cells incubated with AXrb were collected and analyzed for IL-2 and IFN-${\gamma}$ synthesis by ELISA. IL-2 and IFN-${\gamma}$ production were increased significantly. These results suggest that AXrb may induce Th1 immune responses. Macrophages play an important role in host defenses against tumors by killing them and producing secretory products, which protect against bacterial, viral infection and malignant cell growth. AXrb were examined for their ability to induce secretory and cellular responses in murine peritoneal macrophages. When macrophages were treated with various concentrations ($10-100\;{\mu}g/mL$) of AXrb, AXrb induced tumoricidal activity, as well as increasing phagocytosis and the production of NO, $H_2O_2$, TNF-${\alpha}$, IL-$1{\beta}$, and IL-6. These results indicate that reactive oxygen species, reactive nitrogen species, and inflammatory cytokines are likely to be the major mediators of tumoricidal activity in AXrb-treated macrophages. Therefore, AXrb may be useful in cancer immunotherapy and it is anticipated that AXrb obtained using extrusion and subsequent enzyme treatment can be used as an ingredient in nutraceuticals and cereal-based functional food.

• Molecules and Cells
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• v.26 no.2
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• pp.158-164
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• 2008

Arsenic trioxide (ATO) affects many biological processes such as cell proliferation, apoptosis, differentiation and angiogenesis. L-buthionine sulfoximine (BSO) is an inhibitor of GSH synthesis. We tested whether ATO reduced the viability of lung cancer A549 cells in vitro, and investigated the in vitro effect of the combination of ATO and BSO on cell viability in relation to apoptosis and the cell cycle. ATO caused a dose-dependant decrease of viability of A549 cells with an $IC_{50}$ of more than $50{\mu}m$. Low doses of ATO or BSO ($1{\sim}10{\mu}m$) alone did not induce cell death. However, combined treatment depleted GSH content and induced apoptosis, loss of mitochondrial transmembrane potential (${\Delta}{\Psi}_m$) and cell cycle arrest in G2. Reactive oxygen species (ROS) increased or decreased depending on the concentration of ATO. In addition, BSO generally increased ROS in ATO-treated A549 cells. ROS levels were at least in part related to apoptosis in cells treated with ATO and/or BSO. In conclusion, we have demonstrated that A549 lung cells are very resistant to ATO, and that BSO synergizes with clinically achievable concentration of ATO. Our results suggest that combination treatment with ATO and BSO may be useful for treating lung cancer.

• Korean Journal of Materials Research
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• v.15 no.4
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• pp.263-270
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• 2005

In order to prepare the uniform copper particles from copper chloride solution, the reduction behavior of copper particles from copper chloride and the effects of reduction agent and dispersing agent was investigated. In the case that 2.56 M of $C_6H_8O_6$ was used as a reduction agent, the highly dispersed Cu particles with sharp size distribution were generated from 0.96M of copper chloride solution, and the size of Cu particles was $6\~10\;{\mu}m$. To form $Cu(NH_3)_4Cl_2$ complex solution, $NH_4OH$ was added in the copper chloride solution before the reductive reaction of Cu ion. The generated Cu particles have a two kind of shape, spherical and rod-like. In the case that $N_2H_4{\cdot}H_2O$ was used as a reduction agent, the very fine spherical Cu particles with the size of $0.2\~0.5\;{\mu}m$ was obtained. Arabic gum as a dispersing agent was more effective than $Na_4P_2O_7{\cdot}10H_2O$.

• Parasites, Hosts and Diseases
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• v.54 no.2
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• pp.139-145
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• 2016

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an $EC_{50}$ value of $36.2{\mu}M$, compared with $EC_{50}$ values of $248-428{\mu}M$ for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2519-2525
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• 2014

WeI have studied the process for synthesizing porous silica with a specific surface area of minimum $800m^2/g$ by adding surfactant [Poly Etylene Glycol(PEG) and Hydroxy Propyl Cellulose(HPC)] to the sol-gel reaction between sodium silicate and hydrochloric acid. NaCl, the by-product of the sol-gel reaction, was water cleaned and removed; when 200 ml of water was used to clean 50 g of silica gel, NaCl remaining in the silica gel was reduced to maximum 0.81wt%. The appropriate level of surfactant for silica gel synthesizing proved to be below 5%. As a result of the experiment, for the silica synthesized by adding surfactant of HPC(2.5%)+PEG(2.5%), the surfactant area was $860m^2/g$ and grain size was $20-50{\mu}m$. From this study, we have concluded that it is of industrial significance that specific surface area is improved and silica of a regular grain size is obtained just by adding surfactant in the gel process or drying process of silica.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.694-696
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• 2010

We have synthesized boron (or phosphorous) doped silicon nanoparticles (Si-NPs) by a solution process. The surfaces of the Si-NPs were terminated with various alkyl groups to form a protecting layer. The Si-NPs were characterized by UV-Vis, PL, FTIR, and NMR. Through a microwave sintering process, the crystalline thin films of the Si-NPs were prepared by removing the surface alkyl groups. The TEM and SEM images reveal that contiguous films as large as $200{\mu}m$ in diameter were formed with a cubic structure. The electrical conductivity of the Si film was controlled by a doping type.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.81-86
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• 2012

This paper presents a VLSI design for lifting-based discrete wavelet transform (DWT) 9/7 filter using multiplierless multiple constant multiplication (MCM) architecture. This proposed design is based on the lifting scheme using pattern search for folded architecture. Shift-add operation is adopted to optimize the multiplication process. The conventional serial operations of the lifting data flow can be optimized into parallel ones by employing paralleling and pipelining techniques. This optimized design has simple hardware architecture and requires less computation without performance degradation. Furthermore, hardware utilization reaches 100%, and the number of registers required is significantly reduced. To compare our work with previous methods, we implemented the architecture using Verilog HDL. We also executed simulation based on the logic synthesis using $0.18{\mu}m$ CMOS standard cells. The proposed architecture shows hardware reduction of up to 60.1% and 44.1% respectively at 200 MHz clock compared to previous works. This implementation results indicate that the proposed design performs efficiently in hardware cost, area, and power consumption.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4745-4750
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• 2012

In this paper a $6^{th}$ 1MHz~30MHz bandpass filter for Power line communication(PLC) modem receiver is designed using current mode synthesis method which is good to design the low-voltage and low-power filter. The designed bandpass filter is composed of cascade connecting between $3^{rd}$ Butterworth highpass filter and $3^{rd}$ Chebychev lowpass filter. As a core circuit in the current-mode filter, a current-mode integrator is designed with new architecture which can improve gain and unity gain frequency of the integrator. The gain and the unity gain frequency of the designed integrator is each 32.2dB and 247MHz. And the cutoff frequency of the designed $6^{th}$ bandpass filter can be controlled to 50MHz from 200KHz according to controlling voltage and the power consumption is 2.85mW with supply voltage, 1.8V. The designed bandpass filter was verified using a $0.18{\mu}m$ CMOS parameter.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1491-1494
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• 2008

A novel platinum aminoalkoxide complex, Pt$(dmamp)_2$ has been prepared by the reaction of cis-$(py)_2PtI_2$ with two equivalents of Na(dmamp) (dmamp = 1-dimethylamino-2-methyl-2-propanolate). Single-crystal X-ray crystallographic analysis shows that the Pt(dmamp)2 complex keeps a square planar geometry with each two nitrogen atoms and two oxygen atoms having trans configuration. Platinum films have been deposited on TaN/ Ta/Si substrates by metal organic chemical vapor deposition (MOCVD) using Pt$(dmamp)_2$. As-deposited platinum thin films did not contain any appreciable amounts of impurities except a little carbon. As the deposition temperature was increased, the films resistivity and deposition rate increased. The electrical resistivity (13.6 $\mu\Omega$cm) of Pt film deposited at 400 ${^{\circ}C}$ is a little higher than the bulk value (10.5 $\mu\Omega$cm) at 293 K. The chemical composition, crystalline structure, and morphology of the deposited films were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, and atomic force microscopy.

• Korean Journal of Crystallography
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• v.17 no.1
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• pp.6-9
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• 2006

Crystal structure of Bis(N-Methylphenazinium)-Tetracyanopalladate(II) hydrate has been determined by X-ray crystallography. Crystal data: $(C_{13}H_{11}N_2){_2}[Pd(cn)_4]{\cdot}H_2O$, Monocline, Space group $P2_1/b$(No=14), a=9.783(4), b=10.788(4), c=13.666(4) ${\AA},\;{\beta}=104.59(5),\;Z=2,\;V=1392.9{\AA}{^3},\;Dc=1.476gcm^{-3},\;F(000)=632,\;{\mu}=7.05cm^{-1}$. The structure was solved by Patterson method and refined by full matrix least-square methods using unit weights. The final R and S values were R=0.0257, Rw=0.0732, Rall=0.0283 and S=1.07 for 1930 observed reflections. Both cation and anion complexes are essentially planar and have dihedral angles of $10.16(4)^{\circ}$. The planar complex anions are sandwiched between slightly bent cations. The interplanar separations in one triad and between two triads are 3.419(3) and $3.402(4){\AA}$, respectively. The triads are stacked along b-axis.