• Journal of radiological science and technology
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• v.23 no.1
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• pp.81-89
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• 2000

In the present study, to determine whether the ascorbate protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of ascorbate(240 mg/kg, i.p) pretreatment of mice on the survival ratio, splenic weight, major antioxidant enzymes(SOD, catalase and glutathione peroxidase) activities, glutathione contents and lipid peroxidation in the liver were examined for 2 weeks after whole-body ${\gamma}-irradiation$(6.5 Gy). The 30-day survival ratio Increased from 10% to 47% for mice treated with ascorbate. The ascorbate decreased the extent of loss in splenic weight and stimulated recovery of splenic weight in irradiated mice(p<0.01). On the day of 14 after ${\gamma-irradiation}$, the ascorbate pretreatment produced a slight increase of antioxidant enzymes activities and significantly increased reduced glutathione(GSH) contents(P<0.05) in the liver compared with non-treated group. Pretreatment with the ascorbate significantly decreased GSSG/total GSH ratio(p<0.05) without the change of GSSG in the liver and inhibited the radiation-induced increase in the hepatic malondialdehyde levels(p<0.05). In these results, we found that its radioprotective effect by protecting antioxidant enzyme activities and glutathione contents from radiation induced a decrease, and thereby suppressing lipid peroxidation which is induced by free radicals.

• Journal of Ginseng Research
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• v.31 no.3
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• pp.127-136
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• 2007

Ginseng, the root of Panax species, is a well-known herbal medicine. It has been used as traditional medicine in Korea, China and Japan for thousands of years and now is a popular and worldwide natural medicine. The active principles of ginseng are ginsenosides which are also called ginseng saponins. Traditionally ginseng has been used primarily as a tonic to invigorate weak body functions and help the restoration of homeostasis. Current in vivo and in vitro studies demonstrate its beneficial effects in a wide range of pathological conditions such as cardiovascular diseases, cancer, immune deficiency and hepatotoxicity. Moreover, recent research indicates that some of ginseng's active ingredients exert beneficial actions on aging and neurodegenerative disorders such as Parkinson´s disease. Essentially, antioxidant, antiinflammatory, anti-apoptotic and immunostimulant activities are mostly underlying the postulated ginseng-mediated protective mechanisms. Next to animal studies, data from neural cell cultures contribute to the understanding of these mechanisms which involve decreasing nitric oxide, scavenging of free radicals and counteracting excitotoxicity. This paper focuses on own and other neuroprotective data on ginseng for dopaminergic neurons and intends to show aspects where neuroprotection e.g. by ginsenosides, additionally or preceding standard Parkinson therapy, could come about as a valuable contribution to slow neurodegenerative processes.

• Journal of Pharmaceutical Investigation
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• v.12 no.1
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• pp.12-22
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• 1982

The experimental study have showed that the Polygonatum officinale All. contains diosgenin and ${\beta}-sitosterol$ as active components. Even though many experimental studies were reported, still there are many unknown actions of components from the plant. The purpose of this study was to elucidate the mechanism of hypoglycemic action of ether extract of Polygonatum officinale. The hypoglycemic effect of the ether extract was tested in hyperglycemic rats induced experimentally, The effect on plasma free fatty acid and the acute toxicity were also examined by using mouse. The hypoglycemic effect of the ether extract was compared with other oral hypoglycemic agents such as chlorpropamide and buformin. The ether extract of Polyonatum officinale showed a marked hypoglycemic effect by 1 hour after oral administration in hyperglycemic rats and rabbits but the ethanol extract did not exhibit the hypoglycemic effect. The hypoglycemic effect of the ether extract was potentiated by chlorpropamide while buformin was weak.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.40-40
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• 2003

Spontaneous firing rate and patterns of dopaminergic neurons in midbrain are key factors in determining the level of dopamine at target loci as well as in the mechanisms such as reward and motor coordination. Although glutamate, as a major afferent, is reported to enhance firing rate, the detailed actions of NMDA-, AMPA/kainate-, and metabotropic glutamate receptors (mGluR) on filing patterns are not clear. Thus we have investigated the role of glutamate receptors on the spontaneous firing activities using the network-free, acutely isolated dopamine neurons from substantia nigra pars compacta(SNc) of the 9-14 days rat. The isolated cells showed spontaneous regular firings of near 2.5 Hz, whose rate was enhanced by glutamate at submicromolar levels (0.3 $\square$M) but abolished by high concentrations more than 10 $\square$M.

• YAKHAK HOEJI
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• v.31 no.6
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• pp.376-393
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• 1987

This study was performed in order to investigate the effect of nifedipine, a vasodilating drug which acts through calcium antagonism, on renal function using mongrel dog. Nifedipine, when given interavenously in doses ranging from 1.5 to 5.0$\mu\textrm{g}$/kg, elicited diuresis along with less changes of glomerular filtration rate and significant increases of renal plasma flow, so that the filtration fraction(FF) decreased significantly, at the same time both osmolar and free water clearances increased, and amount of sodium, potassium and calcium excreted in urine increased significantly. Nifedipine, when infused into a renal artery in doses from 0.05 to 0.15$\mu\textrm{g}$/kg/min, exhibited identical responses to the actions of intraveneous nifedipine except significant increase of glomerular filtration rate and no change of FF, which was confined only to the infused kidney. The renal action of nifedipine into a renal artery were not influenced by renal denervation, decreased significantly by ouabain, Na$^+$-K$^+$-ATPase inhibitor, which was given into a renal artery. Nifedipine infused into a renal artery in dog pretreated with propranolol i.v. produced diuresis associated with the increase of electrolytes excretion by reduction of electrolyte reabsorption and with no changes of glomerular filtration rate and renal plasma flow. Thus, it is concluded that nifedipine infused into a renal aretery produces diuretic action along with both improvement of hemodynamics and inhibition of electrolytes reabsorption, which may be related to sympathetic $\beta$-receptor or Na$^+$-K$^+$-ATPase activity because the action of nifedipine in kidney is blocked by propranolol or ouabain.

• Journal of Ginseng Research
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• v.22 no.1
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• pp.1-10
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• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• East Asian Economic Review
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• v.22 no.2
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• pp.177-215
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• 2018

Trump's withdrawal from the Trans-Pacific Partnership (TPP) and his "America First" trade agenda ignite a second round of interest in mega-free trade agreements in the Asia-Pacific. Countries are evaluating alternative trade policy actions in a post-TPP era. Using national real GDP gains estimated by a modified GTAP model to construct "preference ordering" for 10 Association of Southeast Asian Nations members and their six regional dialogue partners, this paper comes up with several policy-oriented findings. First, when multilateral agreements are not possible, countries are better off with a regional trading agreement than without one. Second, the Regional Comprehensive Economic Partnership is likely to have higher beneficial impacts than the Comprehensive and Progressive Agreement for Trans-Pacific Partnership. Third, for dual-track countries, implementing both agreements is better than each separately. Fourth, impacts of open regionalism are likely to be higher than those of a closed and reciprocal one. Going forward, this paper argues that countries should adopt a "multi-track, multi-stage" approach to trade policy.

• Current Photovoltaic Research
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• v.3 no.4
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• pp.112-115
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• 2015

In this study, the surface of ITO films was modified using $N_2-O_2$ molecular plasma, and the effects of oxygen concentration in the plasma on the ITO surface properties were investigated. Upon plasma treatment of ITO films, the surface roughness of ITO films seldom changed up to the oxygen concentration in the range of 0% to 40%, while the roughness of the films slightly changed at or above the oxygen concentration of 60%. The contact angle of water droplet on ITO films dramatically changed with varying oxygen concentration in the plasma, and the minimum value was found to be at the oxygen concentration of 20%. The plasma resistance at this condition exhibited a maximum value, and the change of resistance showed an inverse relationship compared to that of contact angle. From these results, it was conjectured that the chemical reactions in the sheath of the molecular plasma dominated more than the physical actions due to energetic ion bombardment, and also the plasma resistance could be used as an indirect indicator to qualitatively diagnosis the state of plasma during the plasma treatment.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.392-398
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• 1994

The purpose of this study was to predict the actions and roles of 10 strains of representative psychrotrophic lactic acid bacteria, in kimchi fermentation, which were Isolated from kimchi and identified as Leu. mesenteroides subsp. mesenteroides, Leu. mesenteroides subsp. dextranicum, Leu. lactic, Leu. paramesenteroides, Lac. bavaricus and Lac. homahiochii. For this, 0.01% of tactic starters were inoculated in germ free Korean cabbage-juice containing 2.5% NaCl, and then cultivated for 14 days at 1$0^{\circ}C$. All strains grew actively, and reached their stationary phase in 4 days. In death phase, the slopes of curves were much different each other by strains. The acidity increased rapidly between 2 and 4 days, and the pH decreased rapidly between 2 and 3 days. The total acidity was 0.5B~0.75%, the volatile acidity 0.04~0.18% and the pH 3.55~3.85, in final cultures. The cultures of Leuconostocs were better than those of lactobacilli on flavor test. It was thought that the ripening periods of kimchi would be much reduced, and that the over ripening would be also somewhat avoided, when these strains were used as starter bacteria for kimchi and the kimchi was fermented at low temperature.

• Geomechanics and Engineering
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• v.11 no.6
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• pp.805-820
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• 2016

A fully coupled non-linear effective stress response finite difference (FD) model is built to survey the counter-intuitive recent findings on the reliance of pore water pressure ratio on foundation contact pressure. Two alternative design scenarios for a benchmark problem are explored and contrasted in the light of construction emission rates using the EFFC-DFI methodology. A strain-hardening effective stress plasticity model is adopted to simulate the dynamic loading. A combination of input motions, contact pressure, initial vertical total pressure and distance to foundation centreline are employed, as model variables, to further investigate the control of permanent and variable actions on the residual pore pressure ratio. The model is verified against the Ghosh and Madabhushi high acceleration field test database. The outputs of this work are aimed to improve the current computer-aided seismic foundation design that relies on ground's packing state and consistency. The results confirm that on seismic excitation of shallow foundations, the likelihood of effective stress loss is greater in deeper depths and across free field. For the benchmark problem, adopting a shallow foundation system instead of piled foundation benefitted in a 75% less emission rate, a marked proportion of which is owed to reduced materials and haulage carbon cost.