• Radiation Oncology Journal
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• v.8 no.1
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• pp.1-6
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• 1990

In the present study, a perfluorchemical emulsion (Fluosol-DA $20\%$) did not alter $D_o\;and\;D_q$ values on cell survival curve, indicating that the lack of a direct effect of Fluosol-DA $20\%$ on cellular radiosensitivity in vitro. The effect of Fluosol-DA $20\%$ injection in combination with carbogen breathing was determined on the hypoxic cell fraction in SCK tumors. The hypoxic cell fraction in control SCK tumors was 0.39. This value decreased to 0.05 when the mice were i.v. injected with 12 ml/kg of Fluosol-DA $20\%$ in a carbogen atomosphere. The measured mean and median $PO_2$ values with a microelectrode in the control tumors was 9 mmHg and 4 mmHg, respectively. The treatment of the SCK tumors in the host mice with injected Fluosol-DA $20\%$ in combination with carbogen breathing increased the mean and median $PO_2$ values to 67 mmHg and 62 mmHg, respectively. Using carbogen breathing alone caused a moderate increase of tumor $PO_2$. But Fluosol-DA $20\%$ injection alone caused little change $PO_2$ in the tumor. It was concluded that the combination of Fluosol-DA injection and carbogen breathing is an effective means to improve oxygenation of tumors.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.604-609
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• 2016

In postmenopausal women, estrogen deficiency can be associated with metabolic diseases, such as obesity, diabetes, and cardiovascular diseases. The purpose of this study was to investigate factors related to lipid, glucose and antioxidnat metabolism. Sprague-Dawley female rats were subjected to either bilateral ovariectomy or sham operation and randomly divided into 3 dietary groups, (n=8) sham-operated fed with normal diet (SHAM), ovariectomized fed with normal diet (OVX), and ovariectomized fed with normal diet supplemented with Eucommia ulmoides extract (OVX-EU). The OVX-EU group showed significantly lower body weight, triacylglycerol, and total cholesterol than that showed by the OVX group. In addition, the OVX-EU group showed improved lipogenesis, glucose-regulating enzyme activities, adipokine and antioxidant enzyme activities. These findings demonstrate that extracts from E. ulmoides extract can be used as a functional food.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.7-11
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• 2016

The aerial part of Trichosanthes kirilowii Maxim. (Cucurbitaceae), has long been used in traditional Korean and Chinese medicines for the treatment of heatstroke. We isolated and identified three flavones, luteolin-7-O-${\beta}$-D-glucopyranoside(1), luteolin-4'-O-${\beta}$-D-glucopyranoside(2), luteolin(3) from its methanolic extract. In the present study, we found that luteolin attenuates the lipopolysaccharide(LPS)-induced inflammation in BV2 microglial cells. Luteolin significantly inhibited LPS-induced production of pro-inflammatory mediators such as nitric oxide(NO) and prostaglandin $E_2(PGE_2)$ in BV2 microglia in a concentration-dependent manner without cytotoxic effect. Luteolin dose-dependently suppressed the protein expression of inducible nitric oxide synthase(iNOS) and cyclooxygenase-2(COX-2). In addition, luteolin also showed significant induction of heme oxygenase(HO)-1. These results suggest that both the aerial part of T. kirilowii and luteolin may be good candidates to regulate LPS-induced inflammatory response.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.22-30
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• 1985

Protoplasts of Pisum sativum L. were isolated and cultured from leaf mesophyll tissue. The successful yield of protoplast was obtained in an enzyme solution of 2% 'Onozuka R-10' and 2 % 'Macerozyme R-10' contained 6mM $CaCl_2{\cdot}2H_2O$ within 4 hours. They were divided in B5 culture medium supplemented with 2mg/l kinetin, 1mg/l 2, 4-D and 0.2% Difcobacto agar. Divisions of the protoplasts were continued and led to colony formation for 1 months. The colony from protoplasts of pea mesophyll tissue was formed to callus after subculture in a medium contained macronutrients and amino acids of BII medium and micronutrients and vitamins of B5 medium, and also supplemented with 2mg/l kinetin 2mg/l NAA.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.51-57
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• 1999

To search for antioxidative compounds from plant resources, methanol extracts of 45 plant species were investigated using DPPH method. The highest activity was shown in the methanol extract of Acer ginnala($RC_{50}\;:\;15{\mu}g$), followed by Stewartia koreana($RC_{50}\;:\;28{\mu}g$) and Carpinus laxiflora($RC_{50}\;:\;33{\mu}g$). Two antioxidative compounds were isolated from the methanolic extract of Acer ginnala Max and identified as acertannin(2, 6-di-O-galloyl-1, 5-anhydro-D-glucitol) and gallicin (methyl-3, 4, 5-trihydroxybenzoic acid) on the basis of mass spectroscopy, $^1H-\;and\;^{13}C-NMR$ data. The DPPH free radical scavenging activities of acertannin($RC_{50}\;:\;3.5{\mu}g$) and gallicin($RC_{50}\;:\;2.8{\mu}g$) were more effective than those of BHA($RC_{50}\;:\;14{\mu}g$) and ${\alpha}-tocopherol$ ($RC_{50}\;:\;12{\mu}g$).

• KSBB Journal
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• v.9 no.2
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• pp.211-223
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• 1994

In fermentations with a 4-liter stirred tank bioreactor, a better than two-fold enhancement of the gas-liquid mass transfer coefficient$(k_La)$ in the celite-immobilized fungal cultures of Tolypocladium in flatum over the parallel conventional free-cell was observed at identical biomass concentrations, despite the higher specific oxygen uptake rate of the immobilized fungi during exponential growth. As a result oxygen sufficient conditions, i. e., dissolve oxygen(D.O.) concentrations exceeding 75% air saturation, could be maintained throughout exponential growth period of the immobilized culture, in contrast to the suspended fungal culture, whose D.O. levels fell below 50% air saturation. A linear monotonic dependence of $k_La$ upon impeller agitaion rate was found for both immobilized and conventional cultivation modes over a range of 250 to 550rpm, the slope being a function of biomass concentration for the free but not for the immobilized cell system In contrasts oxygen transfer rate was a much weaker function of aeration rate up to about 2.5 vvm for both culture configurations. Above this level, aeration rate had no further effect on the mass transfer. In addition, the immobilized cultures sustained good morphological and physiological states, leading to almost two times higher cyclosporln A (CyA) productivity overt the parallel free cell system. These experiments suggest that the celite-immobilized fungal system in a stirred tank reactor has considerable promise for scaling up cyclosporin A production in terms of high-density cultivation.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.227-231
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• 1974

During the period from 1971 to 73 physiologic races of potato late blight pathogen, Phytophthora infestans, causing severe losses of seed potato production at Alpine area, Korea, were investigated. In 1971, 68 isolates of the pathogen from various potato varieties were identified by the use of differential host Plants, and found that there were 10 races; 0, 1, 2, 3, 1.3, 1.4, 3.4, 1.3.4, 2.3.4. The most Predominant races for the year were 0 and 3. In 1972, the same procedure was repeated with 62 isolates of the pathogen, and found 5 different races; 0, 1, 4, 1.3 and 1.3.4. The most predominant race for the year was race 0. In 1973, six races; 0, 3, 4, 1.3, 3.4 and 1.3.4 were found from 76 isolates of the year, and the race 0 and 4 apperared as the most Predominant races for the year. Total of 11 races; 0, 1, 3, 4, 1.3, 1.4, 3.4, 1.3.4, 2.3.4 and 1.2.3.4, were found during the period from 1971 to 73 at Alpine area, among which the most predominant races were race 0, 3, and 4. The investigation indicated that the anual incidence of these races largely depended on the climatic conditions of the year.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.1
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• pp.11-23
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• 1997

This paper contains a new approach to blade section design method for marine propellers. The hydrodynamic characteristics of 2-D section are highly influenced by its geometrical parameters i.e., thickness and camber distributions and leading edge radius etc. To consider fully turbulent flow field near 2-D section. the finite volume method with k-${\varepsilon}$ turbulent model which solve Reynolds time averaged Navier-Stokes(RANS) equation is applied. In this study, O-type grid system that can provide many calculation points on blade surface is used. The results were compared with those of the experiment of NACA0012 to confirm the accuracy of the developed codes. The goal of this study is the development of a blade section with high efficiency and low drag. To achieve this, we carried out the tests of lift, drag and cavitation characteristics in cavitation tunnel. The results of experiment were compared with numerical results in order to validate the proposed blades design method. By comparing the numerical results with the experiments, we found that the new blade section, KH28 allows superior performance in efficiency and cavitation avoidance characteristics. We further investigated the blade section design method and an application study of this section, KH28 to apply to the marine propeller. In order to improve the accuracy of numerical results on prediction of lift and drag, we conclude here that the 2-layer boundary model must be used.

• Advances in nano research
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• v.16 no.4
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• pp.325-340
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• 2024

There are several novel uses for dispersing many nanoparticles into a conventional fluid, including dynamic sealing, damping, heat dissipation, microfluidics, and more. Therefore, melting heat and mass transfer characteristics of a 3-D MHD Hybrid Nanofluid flow over a rotating disc with presenting dufour and soret effects are assessed numerically in this study. In this instance, we investigated both ferric sulfate and molybdenum disulfide as nanoparticles suspended within base fluid water. The governing partial differential equations are transformed into linked higher-order non-linear ordinary differential equations by the local similarity transformation. The collection of these deduced equations is then resolved using a Chebyshev spectral collocation-based algorithm built into the Mathematica software. To demonstrate how different instances of hybrid/ nanofluid are impacted by changes in temperature, velocity, and the distribution of nanoparticle concentration, examples of graphical and numerical data are given. For many values of the material parameters, the computational findings are shown. Simulations conducted for different physical parameters in the model show that adding hybrid nanoparticle to the fluid mixture increases heat transfer in comparison to simple nanofluids. It has been identified that hybrid nanoparticles, as opposed to single-type nanoparticles, need to be taken into consideration to create an effective thermal system. Furthermore, porosity lowers the velocities of simple and hybrid nanofluids in both cases. Additionally, results show that the drag force from skin friction causes the nanoparticle fluid to travel more slowly than the hybrid nanoparticle fluid. The findings also demonstrate that suction factors like magnetic and porosity parameters, as well as nanoparticles, raise the skin friction coefficient. Furthermore, It indicates that the outcomes from different flow scenarios correlate and are in strong agreement with the findings from the published literature. Bar chart depictions are altered by changes in flow rates. Moreover, the results confirm doctors' views to prescribe hybrid nanoparticle and particle nanoparticle contents for achalasia patients and also those who suffer from esophageal stricture and tumors. The results of this study can also be applied to the energy generated by the melting disc surface, which has a variety of industrial uses. These include, but are not limited to, the preparation of semiconductor materials, the solidification of magma, the melting of permafrost, and the refreezing of frozen land.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.959-970
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• 2000

A laboratory-scale experiment was conducted to investigate the effect of soluble microbial products(SMP) on permeate flux in the submerged membrane separation activated sludge process. Continuous and batch filtration test were operated to understand mechanism of relationship between membrane fouling and SMP. Synthetic wastewater(phenol) was used as a carbon source. Hydraulic retention time(HRT) and mixed-liquor volatile suspended solids(MLVSS) of the reactor were kept at 12 hours and 9.000mg VSS/L, respectively. Batch filtration tests ($J_{60}/J_o$) using the mixed liquor from reactor showed that the increase of accumulated SMP concentration in the reactor caused to the decreasing permeate flux and the increasing of the adhesion matters which form cake and gel layer. The resistance value of cake layer was measured $2.9{\times}10^{10}{\sim}4.0{\times}10^{10}(1/m)$, this value showed more significant effect on flux drop than that of among other resistance layers. Batch phenol-degradation experiment was conducted to observe SMP type expected $SMP_{nd}$ and $SMP_{e}$ (SMP resulted from endogenous cell decomposition), these are non-biodegradable high molecular weight organic matter and playa significant role in permeate flux drop. Also, SMP concentration was accumulated as increased of HRT against flux drop.