• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.380-391
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• 2003

Surface sediments were collected from Gwangyang and Yeosu Bays to evaluate their sedimentological characteristics and geochemical aspects of both the benthic environment and heavy metal pollution. The grain size distribution includes both sandy and muddy sediments. Sand-rich sediments occur mainly near the POSCO and the channel between Namhedo and Yeosu Bando, while elsewhere mud-dominated sediments are present. TOC content ranges from 0.2 to 2.1 % and C/N ratios indicate that the range arises from the mix of organic matter. The C/S ratios of this organic matter show that parts of the study area are anoxic or have sub-anoxic bottom conditions. The hydrogen sulfide content of the sediment has a range of 0.7 to 301 ppm, with a high content occurring inshore of Myodo Island, where it indicates a polluted environment. The enrichment factor (Ef) and index of accumulation rate (Igeo) of ten heavy metals (Co, Ni, Cu, Cd, Pb, Li, Zn, V, Cr, Ba) show that parts of the study area contain from one to seven times more Pb and Ba, and from 0.8 to 3.5 times more of the other elements than the mean sediment value. The Igeo values of V and Cd show that different parts of the area can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted. Those areas that have both high levels of enrichment and high accumulation rates of heavy metals contain predominantly fine sediments with a high organic matter and hydrogen sulfide content.

• Journal of Soil and Groundwater Environment
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• v.17 no.5
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• pp.49-55
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• 2012

A 1.28 L-batch reactor and continuous-flow stirred tank reactor (CFSTR) fed with formate and trichloroethene (TCE) were operated for 120 days and 56 days, respectively, to study the effect of formate as electron donor on anaerobic reductive dechlorination (ARD) of TCE to cis-1,2-dichloroethylene (c-DCE), vinyl chloride (VC), and ethylene (ETH). In batch reactor, injected 60 ${\mu}mol$ TCE was completely degraded in the presence of 20% hydrogen gas ($H_2$) in less than 8 days by anaerobic dechlorination mixed-culture (300 mg-soluble protein), Evanite Culture with ability to completely degrade tetrachloroethene (PCE) and -TCE to ETH under anaerobic conditions. Once the formate was used as electron donor instead of hydrogen gas in batch or chemostat system, the TCE-dechlorination rate decreased and acetate production rate increased. It indicates that the concentration of hydrogen produced in both systems is possibly more close to threshold for homoacetogenesis process. Soluble protein concentration of Evanite culture during the batch test increased from 300 mg to 688 mg for 120 days. Through the protein monitoring, we confirmed an increase of microbial population during the reactor operation. In CFSTR test, TCE was fed continuously at 9.9 ppm (75.38 ${\mu}mol/L$) and the influent formate feed concentration increased stepwise from 1.3 mmol/L to 14.3 mmol/L. Injected TCE was accumulated at 18 days of HRT, but TCE was completely degraded at 36 days of HRT without accumulation of the injected-TCE during the left of experiment period, getting $H_2$ from fermentative hydrogen production of injected formate. Although c-DCE was also accumulated for 23 days after beginning of CFSTR operation, it reached steady-state in the presence of excessive formate. We also evaluated microbial dynamic of the culture at different chemical state in the reactor by DGGE (denaturing gradient gel electrophoresis).

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.339-343
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• 2000

When plants are exposed to subfreezing temperatures ice crystals are forming within extracelluar space in leaves. The growth of ice crystal is closely related to the degree of freezing injury. It was shown that an antifreeze protein binds to an ice nucleator through hydrogen bonds to prevent growth of ice crystal and also reduces freezing damage. The antifreeze proteins in plants are similar to PR proteins but only the PR proteins induced upon cold acclimation were shown to have dual functions in antifreezing as well as antifungal activities. Three of the genes encoded for CLP, GLP, and TLP were isolated from barley and Kentucky bluegrass based on amino acid sequence revealed after purification and low temperature-inducibility as shown in analysis of the protein. The deduced amino acid of the genes cloned showed a signal for secretion into extracellular space where the antifreezing activity sup-posed to work. The western analysis using the antisera raised against the antifreeze proteins showed a positive correlation between the amount of the protein and the level of freeze tolerance among different cultivars of barely. Besides it was revealed that TLP is responsible for a freeze tolerance induced by a treatment of trinexapac ethyl in Kentucky bluegrass. Analysis of an overwintering wild rice, Oryza rufipogon also showed that an acquisition of freeze tolerance relied on accumulation of the protein similar to CLP. The more direct evidence for the role of CLP in freeze tolerance was made with the analysis of the transgenic tobacco showing extracellular accumulation of CLP and enhanced freeze tolerance measured by amount of ion leakage and rate of photosynthetic electron transport upon freezing. These antifreeze proteins genes will be good candidates for transformation into crops such as lettuce and strawberry to develop into the new crops capable of freeze-storage and such as rose and grape to enhance a freeze tolerance for a safe survival during winter.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.109-116
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• 2010

Morinda citrifolia adventitious roots were cultured in shake flasks using Murashige and Skoog medium with different types and concentrations of auxin and cytokinin. Root (fresh weight and dry weight) accumulation was enhanced at 5 $mg\;l^{-1}$ indole butyric acid (IBA) and at 7 and 9 $mg\;l^{-1}$ naphthalene acetic acid (NAA). On the other hand, 9 $mg\;l^{-1}$ NAA decreased the anthraquinone, phenolic and flavonoid contents more severely than 9 $mg\;l^{-1}$ IBA. When adventitious roots were treated with kinetin (0.1, 0.3 and 0.5 $mg\;l^{-1}$) and thidiazuron (TDZ; 0.1, 0.3 and 0.5 $mg\;l^{-1}$) in combination with 5 $mg\;l^{-1}$ IBA, fresh weight and dry weight decreased but secondary metabolite content increased. The secondary metabolite content (including 1,1-diphenyl-2-picrylhydrazyl activity) increased more in TDZ-treated than in kinetin-treated roots. Antioxidative enzymes such as catalase (CAT) and guaiacol peroxidase (G-POD), which play important roles in plant defense, also increased. A strong decrease in ascorbate peroxidase activity resulted in a high accumulation of hydrogen peroxide. This indicates that adventitious roots can grow under stress conditions with induced CAT and G-POD activities and higher accumulations of secondary metabolites. These results suggest that 5 $mg\;l^{-1}$ IBA supplementation is useful for growth and secondary metabolite production in adventitious roots of M. citrifolia.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.340-345
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• 2004

Our work in this study was made in the microsomal fraction to evaluate the lipid peroxidation by measuring superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) and to elucidate the preventive role of CS in the $CCl_4$-induced oxidative stress. The excessive lipid peroxidation by free radicals derived from $CCl_4$ leads to the condition of oxidative stress which results in the accumulation of MDA. MDA is one of the end-products in the lipid peroxidation process and oxidative stress. MDA, lipid peroxide, produced in this oxidative stress causes various diseases related to aging and hepatotoxicity, etc. Normal cells have a number of enzymatic and nonenzymatic endogenous defense systems to protect themselves from reactive species. The enzymes in the defense systems, for example, are SOD, CAT, and GPx. They quickly eliminate reactive oxygen species (ROS) such as superoxide anion free radicalㆍO$^{[-10]}$ $_2$, hydrogen peroxide $H_2O$$_2$ and hydroxyl free radicalㆍOH. CS inhibited the accumulation of MDA and the deactivation of SOD, CAT and GPx in the dose-dependent and preventive manner. Our study suggests that CS might be a potential scavenger of free radicals in the oxidative stress originated from the lipid peroxidation of the liver cells of $CCl_4$-treated rats.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.818-823
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• 2012

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.

• Journal of Korean Medicine for Obesity Research
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• v.18 no.2
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• pp.96-105
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• 2018

Objectives: The aim of this study was to examine the effect of Asparagus cochinchinensis (AC) and fermented AC (fAC) on microorganisms and efficacies. Methods: AC was fermented for four weeks without using any bacterial strains. Then we investigated fermentation characteristics including potential of hydrogen (pH), total sugar, microbial profiling and antioxidant compound contents such as total polyphenol and total flavonoid. The anti-obesity effects of AC and fAC were evaluated by using Oil Red O staining in 3T3-L1 adipocyte. Also anti-diabetic effects of them were evaluated by using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) uptake in C2C12 skeletal muscle cell. Results: Both pH and total sugar of fAC were decreased significantly compared to unfermented AC. And the abundance of total bacteria and lactic acid bacteria increased during fermentation, especially Lactobacillus plantarum. Also fermentation of AC increased the content of total polyphenol. On the metabolic aspects, we found that AC and fAC suppressed fat accumulation. Conclusions: After four weeks of fermentation, AC increased concentrations of active compounds, altered microbial composition, and inhibited fat accumulation such as triglyceride. These results indicate that fermentation of AC might be a beneficial therapeutic approach for obesity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Natural Product Sciences
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• v.24 no.3
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• pp.148-154
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• 2018

Chronic oxidative stress due to the accumulation of reactive oxygen species (ROS) in neuronal cells ultimately leads to neurodegenerative diseases. The use of natural therapies for the prevention of ROS-induced cell damage and for the treatment of neurodegenerative disorders has shown promising results. In this study, we evaluated the neuroprotective effects of the ethyl acetate (EtOAc) fraction of A. okamotoanum against the hydrogen peroxide ($H_2O_2$)-induced oxidative stress in C6 glial cells. Results show that cell viability was decreased in cells incubated with $H_2O_2$, whereas the addition of EtOAc fraction treatments in such cells significantly increased viability. The EtOAc fraction showed the highest inhibitory activity against ROS production and it also decreased the expressions of inflammatory proteins including cyclooxygenase-2, inducible nitric oxide synthase and interleukin-$1{\beta}$. Furthermore, the EtOAc fraction inhibited apoptosis by regulating the protein expressions cleaved caspase -9, -3, poly ADP ribose polymerase, Bax and Bcl-2. Therefore, these results show that the EtOAc fraction of A. Okamotoanum exhibits neuroprotective effects against $H_2O_2$ induced oxidative damage by regulating the inflammatory reaction and apoptotic pathway.

• Journal of Powder Materials
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• v.20 no.4
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• pp.253-257
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• 2013

Freeze drying for porous Mo was accomplished by using $MoO_3$ powder as the source and camphor-naphthalene eutectic system as the sublimable material. Eutectic composition of camphor-naphthalene slurries with the initial $MoO_3$ content of 5 vol%, prepared by milling at $55^{\circ}C$ with a small amount of oligomeric dispersant, was frozen at $-25^{\circ}C$. The addition of dispersant showed improvement of dispersion stability in slurries. Pores were generated subsequently by sublimation of the camphor-naphthalene during drying in air for 48 h. To convert the $MoO_3$ to metallic Mo, the green body was hydrogen-reduced at $750^{\circ}C$, and sintered at $1100^{\circ}C$ for 2 h. The sintered samples, frozen by heated Teflon cylinder, showed large pores with the size of about 40 ${\mu}m$ which were aligned parallel to the sublimable vehicles growth direction. The formation of unidirectionally aligned pores is explained by the rejection and accumulation of solid particles in the serrated solid-liquid interface.