• Polymer(Korea)
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• v.34 no.6
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• pp.491-494
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• 2010

Colored, electrophoretic polymer nanoparticles of poly (styrene-co-divinylbenzene-co-vinyl acetate)[poly(St-co-DVB-co-VAc)] were prepared by emulsifier-free emulsion co-polymerization and reactive dyeing. The emulsifier-free emulsion polymerization of styrene, divinyl benzene and vinyl acetate was carried out at $70^{\circ}C$ for 20 hrs to obtain monodisperse polymer nanoparticles of poly(St-co-DVB-co-VAc) with an average diameter of 180~200 nm. These nanoparticles were transformed into poly(styrene-co-divinylbenzene-co-vinyl alcohol) [poly(St-co-DVB-co-VA)] nanoparticles through the saponification reaction. The poly(St-co-DVB-co-VA) nanoparticles were treated with reactive dyes to obtain the colored, monodisperse electrophoretic nanoparticles, and their morphology and surface charge were characterized by scanning electron microscopy, differential scanning calorimetry, UV/Vis absorbance and zeta-potentiometry.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.439-454
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• 1993

The phase sequence of codeposited Co-Si alloy and Co/si multilayer thin film was investigated by differential scanning calormetry(DSC) and X-ray diffraction (XRD) analysis, The phase sequence in codeposition and codeposited amorphous Co-Si alloy thin film were CoSilongrightarrow Co2Si and those in Co/Si multilayer thin film were CoSilongrightarrowCo2Silongrightarrow and CoSilongrightarrowCo2Si longrightarrowCoSilongrightarrowCoSi2 with the atomic concentration ration of Co to Si layer being 2:1 and 1:2 respectively. The observed phase sequence was analyzed by the effectvie heat of formatin . The phase determining factor (PDF) considering structural facotr in addition to the effectvie heat of formation was used to explain the difference in the first crystalline phase between codeposition, codeposited amorphous Co-Si alloy thin film and Co/Si multilayer thin film. The crystallinity of Co-silicide deposited by multitarget bias cosputter deposition (MBCD) wasinvestigated as a funcion of deposition temperature and substrate bias voltage by transmission electron microscopy (TEM) and epitaxial CoSi2 layer was grown at $200^{\circ}C$ . Parameters, Ear, $\alpha$(As), were calculate dto quantitatively explain the low temperature epitaxial grpwth of CoSi2 layer. The phase sequence and crystallinity had a stronger dependence on the substrate bias voltage than on the deposition temperature due to the collisional daxcade mixing, in-situ cleannin g, and increase in the number of nucleation sites by ion bombardment of growing surface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.635-644
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• 1994

A mathematical model was developed to predict the concentrations of various nutrients in supernatants during aerobic digestion which is suitable to be employed in small wastewater treatment plants with such advantages as low capital cost and stable process. Significant reactions were determined with observing the behavior of nitrgen and phosphorus, and the model equations were built up in the form of simultaneous differential equations considering Mass Balance. Laboratory batch experiments were carried out at $20^{\circ}C$ and pH $7.5{\pm}0.5$ on the aerobic digestion of waste activated sludge at different solid levels. Nonlinear regression analysis was performed to estimate various reaction rate constants. The developed model can predict the behavior of Biomass N, dissolved organic N, $NH_4{^-}$-N, $NO_x{^-}$-N, and Biomass P, dissolved organic P, $PO_4{^-}$-P in aerobic digestion process. In this study, the results of simulation showed that dissolved nutrients had more effects on supernatants than nutrients in biomass, and phosphorus was more effective on supernatants than nitrogen.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.9
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• pp.1151-1162
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• 1999

The effects of radial heat and $H_2O$ diffusion on the evolution of silica particles in coflow diffusion flames have been studied experimentally. The evolution of silica aggregate particles in coflow diffusion flames has been measured experimentally using light scattering and thermophoretic sampling techniques. The measurements of scattering cross section from $90^{\circ}$ light scattering have been utilized to calculate the aggregate number density and volume fraction using with combination of measuring the particle size and morphology through the localized sampling and a TEM image analysis. Aggregate or particle number densities and volume fractions were calculated using Rayleigh-Debye-Gans and Mie theory for fractal aggregates and spherical particles, respectively. Flame temperatures and volumetric differential scattering cross sections have been measured for different flame conditions such as inert gas species, $H_2$ flow rates, and burner injection configurations to examine the relation between the formation of particles and radial $H_2O$ diffusion. The comparisons of oxidation and flame hydrolysis have also been made for various $H_2$ flow rates using $N_2$ or $O_2$ as a carrier gas. Results indicate that the role of oxidation becomes dominant as both carrier gas($O_2$) and $H_2$ flow rates increases since the radial heat diffusion precedes $H_2O$ diffusion in coflow flames used in this study. The effect of carrier gas flow rates on the evolution of silica particles have also been studied. When using $N_2$ as a carrier gas, the particle volume fraction has a maximum at a certain carrier gas flow rate and as the flow rate is further increased, the hydrolysis reaction Is delayed and the spherical particles finally evolves into fractal aggregates due to decreased flame temperature and residence time.

• Parasites, Hosts and Diseases
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• v.45 no.1 s.141
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• pp.69-74
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• 2007

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction(PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each(520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.

• The Korean Journal of Cytopathology
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• v.15 no.2
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• pp.81-85
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• 2004

Postmenopausal squamous atypia (PSA) is a phenomenon characterized by cellular alterations mimicking condyloma in the uterine cervix of postmenopausal women. It is not associated with human papillomavirus (HPV) infection. The aim of this study is to correlate findings with HPV infection and the cytohistologic findings of PSA. Eighty-three smears from postmenopausal women, initially interpreted as ASCUS and low-grade squamous intraepithelial lesions(LSIL), were reviewed according to the criteria of PSA. Fifty-eight cases were subsequently reclassified as PSA. Forty cases categorized as PSA were available for HPV-DNA detection by a nested polymerase chain reaction. Eight of these 40 cases(20%) showed biopsy-proven LSIL lesions. The HPV-DNA was detected in 42.5%(17/40), compared to 25%(5/20) of control cases. The HPV-DNA detection rate of biopsy-proven LSIL was 62.5%(5/8). It has been concluded that cytologic differential diagnosis of PSA from LSIL is difficult due to because of poor histologic and viral correlation.

• Development and Reproduction
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• v.9 no.1
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• pp.33-41
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• 2005

Identification of differentially expressed genes at blastocyst stage embryos would provide insights into early development and differentiation. Here, we applied a new differential display reverse transcription polymerase chain reaction(DD RT-PCR) technology, called annealing control primers(ACP) system to identify the genes that are specifically or prominently expressed in mouse blastocysts compared to embryonic stem(ES) cells. Using 100 ACPs, 26 clones were perceived as differentially expressed genes in mouse blastocysts. A BLAST search revealed that cloned genes had significant sequence similarities with known genes in the GenBank/EMBL data base. Among them, 15 genes were selected and conformed by RT-PCR. This analysis suggests that the ACP system is a practical method for the identification of stage-specific genes using small numbers of mouse embryos.

• Journal of Pharmacopuncture
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• v.16 no.3
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• pp.30-38
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• 2013

Objectives: Modified regular ginseng extract (MRGX) has stronger anti-cancer activity-possessing gensenoside profiles. Methods: To investigate changes in gene expression in the MRGX-treated lung cancer cells (A549), we examined genomic data with cDNA microarray results. After completing the gene-ontology-based analysis, we grouped the genes into up-and down-regulated profiles and into ontology-related regulated genes and proteins through their interaction network. Results: One hundred nine proteins that were up- and down-regulated by MRGX were queried by using IPA. IL8, MMP7 and PLAUR and were found to play a major role in the anti-cancer activity in MRGX-treated lung cancer cells. These results were validated using a Western blot analysis and a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Conclusions: Most MRGX-responsive genes are up-regulated transiently in A549 cells, but down-regulated in a sustained manner in lung cancer cells.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.55-63
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• 1997

The present study was designed to quantify the alterations of renal renin, angiotensin type I receptor ($AT_1$), $TGF-{\beta}1$, and fibronectin gene expression in rats with unilateral ureteral obstruction (UUO). We also investigated the change of $AT_1$ density during UUO. Reverse transcription-polymerase chain reaction (RT-PCR) technique and receptor binding assay were used to detect mRNA expression and receptor density, respectively. At one day after UUO, renin mRNA level of the obstructed kidneys was decreased transiently and then subsequently increased to the level of sham kidneys. In the contralateral kidneys of the same rats, on the contrary, renin mRNA level was gradually decreased. Then, at 9 days after UUO, it was significantly lower than that of sham kidneys. The expressions of both $AT_1$ subtypes, called $AT_{1A}$ and $AT_{1B}$, mRNAs did not change at any time. UUO led to a significant decrease in $AT_1$ density in the obstructed kidneys compared with the sham kidneys at 1 and 3 days $(66\;{\pm}\;11.6%\;(p<0.005)\;and\;73\;{\pm}\;4.0%$ (p<0.01), respectively). Thereafter, $AT_1$ density was gradually increased and at 9 days it showed a marked elevation in the obstructed kidneys compared to the sham kidneys. In contrast, in the contralateral kidneys $AT_1$ density was significantly reduced from 3 to 9 days after UUO. The $TGF-{\beta}$1 mRNA level of the obstructed kidneys was unexpectedly decreased at 6 days after UUO. Then, at 9 days it was followed by a significant increase in the obstructed kidneys, whereas it showed an obvious decrease in the contralateral kidneys. In addition, fibronectin mRNA level was also significantly increased in the obstructed kidneys after UUO compared to the sham or the contralateral kidneys of the same rats. These results suggest a differential regulation of renal renin, $AT_1$ receptor, $TGF-{\beta}$1 and fibronectin mRNA levels at different stages of UUO.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.533-539
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• 2020

A quantitative real-time polymerase chain reaction (QPCR) was applied to estimate biokinetic coefficients of Clostridium cadaveris and Clostridium sporogenes, which utilize protein as carbon source. Experimental data on changes in peptone concentration and 16S rRNA gene copy numbers of C. cadaveris and C. sporogenes were fitted to model. The fourth-order Runge-Kutta approximation with non-linear least squares analysis was employed to solve the ordinary differential equations to estimate biokinetic coefficients. The maximum specific growth rate (μ_max), half-saturation concentration (K_s), growth yield (Y), and decay coefficient (K_d) of C. cadaveris and C.sporogenes were 0.73 ± 0.05 and 1.35 ± 0.32 h^-1, 6.07 ± 1.52 and 5.67 ± 1.53 g/l, 2.25 ± 0.75 × 10¹⁰ and 7.92 ± 3.71 × 10⁹ copies/g, 0.002 ± 0.003 and 0.002 ± 0.001 h^-1, respectively. The theoretical specific growth rate of C. sporogenes always exceeded that of C. cadaveris at peptone concentration higher than 3.62 g/l. When the influent peptone concentration was 5.0 g/l, the concentration of C.cadaveris gradually decreased to the steady value of 2.9 × 10¹⁰ copies/ml at 4 h Hydraulic retention time (HRT), which indicates a 67.1% reduction of the initial population, but the wash out occurred at HRTs of 1.9 and 3.2 h. The 16S rRNA gene copy numbers of C. sporogenes gradually decreased to steady values ranging from 1.1 × 10¹⁰ to 2.9 × 10¹⁰ copies/ml. C. sporogenes species was predicted to wash out at an HRT of 1.6 h.