• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1296-1302
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• 2000

Objective : Traumatic brain injury including diffuse axonal injury has been shown to result in a decrease in brainfree magnesium concentration, an endogenous inhibitor of calcium entry into neuron, that is associated with the development of neurological motor deficits. The goal of this study is to establish the therapeutic window during which the therapy with $MgSO_4$ and/or hypothermia improve damaged neurons by TUNEL stain. Method : Moderate brain injury was induced in 64 adult Sprague-Dawley rats, weighing 350 to 450gm each, by using a simple weight-drop device(Marmarou model). The animals were randomly assigned to four groups(sixteen rats each, a control group, a group treated with $MgSO_4$, a group treated with hypothermia, and a group treated with $MgSO_4$ and hypothermia) and the rats in each group were sacrificed and studied after 12 hrs, 24 hrs, 1 wk, and 2 wks after insult. In hypothermic group, these rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After 1-hour period of hypothermia, rewarming to normothermic level was accomplished over 30-minute period. In the groups treated $MgSO_4$, hypothermia and $MgSO_4$ were subsequently treated with $MgSO_4$($750{\mu}moles/kg$) infused intra-muscularly at 30 minutes after trauma. Result : In all treated groups, a significant reduction in TUNEL positive cells was found in comparison with the control group each time(p<0.001). Between treatment groups, No differnce was seen 12hrs, 24hrs, and 1wk. However, hypothermic group treated with or without $MgSO_4$ showed more significant reduction in apoptotic cells than group treated with $MgSO_4$ 2 weeks after trauma(p<0.05). However, hypothermic group treated with $MgSO_4$ showed no significant reduction in apoptotic cells compared with hypothermic group(p>0.05). Conclusion : These findings suggest that both hypothermia and $MgSO_4$ significantly improve pathological changes. Otherwise simultaneously $MgSO_4$ and hypothermia treatment groups is failed to provide additional neuroprotection. These results may be relevant to the design of future clinical trials of therapeutic hypothermia and $MgSO_4$ for traumatic brain injury.

• Food Science and Preservation
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• v.23 no.2
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• pp.275-282
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• 2016

STAR of STAR (SS 01-04) is a series of drinks that consist of various extracts obtained from Coriolus versicolor, Artemisia capillaris Thunb., Hovenia dulcis, Acanthopanax sessiliflorus, Lycium chinense, Citrus reticulata, Saururus chinensis, Pueraria lobata, Pyrus pyrifolia, and Oenanthe javanica. A purpose of this study was to investigate the hepatoprotective effect of SS 01-04. Antioxidant activity of the drinks was evaluated by conducting a hydroxyl radical-scavenging assay. Cytotoxicity and hepatoprotective potential were determined using HepG2 cells in vitro, while protective effects against acute hepatotoxicity was evaluated in vivo. The antioxidant activity of the SS 01-04 at concentration of 100 and 250 mg/mL was similar to that of $50{\mu}M$ vitamin C. tert-Butyl hydroperoxide (tBHP)-induced production of reactive oxygen species (ROS) was blocked by SS 01, 03 and 04 in a dose-dependent manner. Treatment with SS 04 significantly lowered the serum levels of alanine aminotransferase and aspartate aminotransferase in an animal model of carbon tetrachloride $(CCl_4)-induced$ hepatotoxicity (p<0.05). In addition, SS04 increased glutathione level while decreased malondialdehyde level in the liver considerably (p<0.05). It also inhibited the $CCl_4-induced$ increase in the levels of triglyceride and cholesterol in serum and the liver. These findings indicated that SS 01-04 possessed antioxidant activity and protect against ROS. In particular, SS 04 is potentially highly beneficial in treating liver damage as it scavenges reactive free radicals and boosts the endogenous antioxidant system.

• Journal of Korea Technology Innovation Society
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• v.22 no.3
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• pp.382-415
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• 2019

This study analyzes the impact of exclusive subcontracting on the input, behavior, and output of innovation in manufacturing industries of Korea. Based on the analysis of pooled cross-sectional data of 6,029 small venture firms, this study proved that the exclusive subcontracting between small venture firms and large enterprises are lowering R&D investment of small venture firms. Second, the innovation activities of small venture firms including the ratio of R&D personnel and the scope of cooperation and partnership with external organizations were lower than those of small venture firms that have non-exclusive or no relations with large enterprises. Third, the innovation performance of small venture firms such as the number of patent applications, the ratio of sales by new products, and the cumulative sales growth rate was lower than those of small venture firms that have non-exclusive or no relations with large enterprises. This study verifies that the exclusive subcontracting relationships significantly weaken the innovation process and performance of small venture firms systematically, resulting in a kind of market failure in which small venture firms have almost no incentive to facilitate innovation.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1998.10a
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• pp.2-4
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• 1998

Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.