• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.710-714
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• 1998

Organic electroluminescence devices (ELD) with hetero-junction structure were fabricated utilizing poly(p-phenylne vinylene) (PPV) as emitting layer and electron transport layer (ETL). 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) was used as an electron transport agent. Copolymers with stilbene type comonomers, such as poly(styrene-co-PVTS), poly(styrene-co-MeO-PVTS) and poly(styrene-co-MeO-ST) were synthesized to be used as a matrix polymer to disperse electron transport agent (PBD). Among the hetero-junction EL devices fabricated with the above materials, the device with poly(styrene-co-PVTS) as matrix polymer for ETL gave the highest luminance ($120.7cd/m^2$, 13 V). EL devices made with poly(styrene-co-MeO-PVTS) or poly(styrene-co-MeO-ST) matrix exhibited lower luminance than the one with polystyrene matrix and the single layer EL (ITO/PPV/Mg) device.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.349-355
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• 2018

Ginsenoside Rg5, one of the protopanaxadiol ginsenosides of wood-cultivated ginseng, has been implicated in various diseases, such as diabetes, cancer, and hypertension; however, its angiogenic activity and molecular mechanisms have not yet been elucidated. Here, we found that wood-cultivated ginseng extract and ginsenoside Rg5 increase in vitro proliferation, migration, and tube-like structure formation, which are typical phenomena associated with angiogenesis, in cultured human umbilical vein endothelial cells (HUVECs). Moreover, Ginsenoside Rg5 stimulated the phosphorylation of Akt, endothelial nitric oxide (NO) synthase (eNOS), and extracellular-regulated kinase (ERK)1/2, which are well-known signal mediators of the angiogenic pathway. Furthermore, Ginsenoside Rg5 did not accelerate the activation of ICAM-1 and VCAM-1 which are inflammatory response mediators. These results suggest that wood-cultivated ginseng extract and ginsenoside Rg5 stimulated in vitro angiogenesis by activating the Akt/eNOS- and ERK1/2-dependent signal pathways without inducing vascular inflammation.

• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.47-52
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• 2008

Purpose：The incidence of papillary thyroid microcarcinoma(PTMC) has increased due to the widespread use of high resolution ultrasonography and fine-needle aspiration biopsy. However, the clinical and biologic behaviors of PTMC is debatable. The aim of this study was to describe clinicopathologic features of PTMC and to suggest whether tumor size(5mm) might prove the useful parameter for determining the surgical strategy in PTMC. Material and Methods：From Jan. 2000 to Dec. 2005, 1355 of 2678 patients with papillary thyroid carcinoma were identified as having PTMC, based on tumor size${\leq}$10mm(50.6%). Among patients with PTMC, we further separated tumors<5mm(minute group：group M) from those 5 to 10mm(tiny group：group T). We compared the clinicopathological characteristics and the TNM stagings between two groups. Results：There were 114(8.4%) men and 1241(91.6%) women with a median age of 47 years(range；13-79). During a mean follow-up of 47.3(range；22-93), 13 patients(1.0%) developed locoregional recurrences and 3 patients(0.2%) showed distant metastases at initial presentation. Statistical analysis revealed that the presence of extracapsular invasion(p<0.0001), invasion to adjacent structure(p<0.0001), multifocality(p<0.0001), central lymph node metastasis(p<0.0001), and lateral lymph node metastasis(p<0.0001) were all significantly higher in tiny group(tumor${\geq}$5mm). Furthermore, minute group demonstrated a significantly lower tumor stage(AJCC TNM classification) compared with tiny group(p<0.0001). Conclusion：Patients with PTMC have a favorable treatment outcomes, although the distinction needs to be made with reference to the clinicopathologic behaviors. It would be reasonable to consider that tumor size(5mm) would be useful parameter for the treatment strategy of PTMC.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.592-604
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• 1999

The steady state and dynamic characteristics of large cell area MCFC stacks were analyzed to solve the problems such as temperature difference generated in stacks and pressure difference between anode and cathode. Manipulated variables (current density, duel utilization rate, oxidant utilization rate) and controlled variables (temperature difference, anode and cathode pressure difference) which had an important effect on the MCFC stack performance were determined using operation results of two types of MCFC stacks (5kW (3,000 $\textrm{cm}^2$, 20 ea). 3kW (6,000 $\textrm{cm}^2$, 5ea)). The stability and transfer function representing system dynamics were obtained by steady state gain rate which showed the relative change between MVs and CVs. The transfer function was a 3$\times$3 matrix and a typical first order system without time delay. The optimal operating condition of large cell area MCFC stacks could be determined by analyzing dynamic characteristics. In case of a 5 kW MCFC stack, pressurized operation with recycle flow should be used to control the outlet temperature less than 68$0^{\circ}C$ and to control the MCFC system effectively. MIMO control or decoupler should be used to remove the interaction between MVs and CVs. This result will be used as important data in determining the control structure design and operation mode of large cell area MCFC systems in the future.

• Nutritional Sciences
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• v.9 no.4
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• pp.267-272
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• 2006

The effect of methanol extract from Agaricus blazei Murill on the hepatotoxicity was investigated $CCl_4$ is one of the oldest and most widely used toxins for the induction of hepatic damages and fibrosis in experimental animals. In this study, male Sprague-Dawley(SD) rats were randomly divided into 6 groups of the control(C), $CCl_4(T),\;CCl_4$ and high fat group(TL) with matching sub-groups of Agaricus blazei Murill extract-fed groups of CA, TA and TLA. Methanol extracts of Agaricus blazei Murill were fed 50 mg/kg B.W daily via drinking water. A 1.2 mL of $CCl_4/kg$ body weight was administered by oral intubation twice a week for total of six times. The levels of total-cholesterol, TG, LDL and LDL-phospholipids were elevated by $CCl_4$ treatment as compared to the control(C). However, Agaricus blazei Murill methanol extract feeding in the group of TA and TLA significantly(p<0.05) decreased TG by 53.1 % and 17.9% compared to the internal control of T and TL, respectively. Triglyceride of TL was increased by 3.33 times(p<0.05) compared to the control(C) with $CCl_4$ and high fat administration from 3.78 mg/g to 12.60 mg/g liver. The extract(CA) also reduced kidney weight compared to the control(C). With the administration of high fat and $CCl_4$(TLA), the extract reduced the organ weight of both liver and kidney and further, significantly reduced TG, total cholesterol and GTP activity. Hepatoprotective effects of Agaricus blazei Murill on GOT, GPT, AP and LDH activities were enhanced by the extract feeding. Electronmicrograph showed that $CCl_4$ deteriorated the structure of cytoplasmic matrix with its uneven distribution. However, the extract reconstituted the damaged cytoplasm and stimulated mitochondriogenesis. The above results suggest that Agaricus blazei Murill may have a possible protective effect against chemically induced liver damage and further help to reduce the symptoms of fatty liver.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.915-923
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• 2017

The by-products of red ginseng marc showing the improvement of health has been strongly studied because of the expectation of possibility to be used as the functional foods. This research was to investigate the extraction, separation, isolation, and evaluation of crude acidic polysaccharides related to antioxidant activity, sequently chemical structure of those products was evaluated by FT-IR and NMR. Compared with other solvents such as ethanol, methanol, propanol, acetone, and butanol, ethanol was selected. The concentration of red ginseng solution for extraction was selected as 10%(w/v) related to extraction yield(11.95%) and amount(11.8 mg/ml). In the ion exchange chromatography, aidic polysaccharides showing the highest antioxidant activity was obtained when eluted by distilled water. As results of structural analysis by FT-IR and NMR, peaks corresponding to C-O, C-O-O-, C-H, anomeric C-6, and repeated C-1 and C-6 linkages was to be presumed to be ($1{\rightarrow}6$) glycosidic linkage with the typical acidic polysaccharide.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.439-444
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• 1993

The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

• Korea Real Estate Review
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• v.24 no.1
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• pp.27-37
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• 2014

Recently increasing the supply of housing policy has not been able to reflect social phenomena as like decreasing birth rate, aging of the population and increasing 1 or 2 person households. This study analyze the housing demand in the city with the point of population growth rate and economic character changes. Growing cities have positive population growth rate and economic character, but shrinking cities have the opposite. By comparing housing demand of growing cities and shrinking cities, we want to find out housing policy implications. In this study, results suggest that the peak age of housing demand of shrinking cities is the late 60's. But the growing cities's age peak is the mid-80's. But further analysis of the economic variables and 1 or 2 person old and young household dummies, the result is that the peak age of housing demand is reduced. These results suggest that housing demand should be differentiated the cities's population structure and economic characteristics of the household. In short, housing demand will vary depending on the condition of individual cities.

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.99-105
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• 2011

This study was conducted to compare the species composition of sessile organisms on the artificial substrates of PVC submerged at different time intervals and duration in Jangmok Bay, Geoje Island, southern coast of Korea. Three PVC plates were submerged at one month interval from March to October and retrieved in November, 2007. A mussel, Mytilus galloprovincialis exclusively occupied the artificial substrates submerged from March to April and occurred as a dominant species to July. An ascidian, Styela plicata occurred as a dominant sessile species from May to August. Balanus amphtrite, Bugula sp., and hydrozoans occurred as dominant species on the plates submerged from July to September. There was a mis-match between the peak time of settlement and dominance of sessile organisms due to the interspecies competitions when the PVC plates were retrieved in November. There was no clear relationship between submerged duration and the abundance of sessile organisms due to the different settlement period. M. galloprovincialis seemed to be a strong competitor which could exclude the previous recruiters of macroalgae by overgrowth and occupy the substrate surface and maintain its high population density by preventing the settlement of other species until late autumn. These results suggested that the composition of sessile organisms in vacant hard substrates could be determined by the combined effects of supply-timing of larvae and post-settlement competitions.

• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.335-340
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• 1998

Colossal magnetoresistance $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ material has been produced by a metal-salt routed sol-gel process method. Magnetic properties of $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ have been studied with x-ray diffraction, Rutherford back-scattering spectroscopy(RBS), vibrating sample magnetometer, and Mossbauer spectroscopy. Crystalline $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ was perovskite cubic structure with a lattice parameter $a_0=3.868$\AA$$. And there was no appreciable change in the value of the lattice parameter when a small amount (x=0.01) of iron was added. However, Mossbauer and VSM data indicate the Curie temperature of the $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ decreased from 282 to 270 k and also the saturation magnetization from 84 to 81 emu/g at 77 K. Mossbauer spectra of $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ have been taken at various temperatures ranging form 4.2 K to room temperature. Analysis of $^{57}Fe$ Mossbauer data in terms of the local configurations of Mn atoms has permitted the influence of the magnetic hyperfine interactions to be monitored. The isomer shifts show that the charge state of all Fe ions are ferric. The magnetoresistance of $La_{0.67}Ca_{0.33}Mn_{0.99}^{57}Fe_{0.01}O_3$ was about 33 % at semiconductor-metal transition temperature $T_{SC-M}=250K$.