• Korean Journal of Materials Research
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• v.30 no.8
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• pp.383-392
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• 2020

In this paper, AgCl/Ag₃PO₄/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag₃PO₄/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag₃PO₄/diatomite composite under visible light are evaluated. In the AgCl/Ag₃PO₄/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag₃PO₄/diatomite remains at 95 % of the original level, much higher than that of pure Ag₃PO₄ (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag₃PO₄/diatomite composites can be attributed to the synergistic effect of Ag₃PO₄, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO₂ and H₂O. Even more remarkably, AgCl/Ag₃PO₄/diatomite can maintain above 95 % photo-degradation activity after five cycles.

• Polymer(Korea)
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• v.32 no.1
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• pp.70-76
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• 2008

The PES-g-BTCA membrane was synthesized by UV irradiation method and then used to be modified into the PES anion exchange membrane by the amination reaction. Their chemical structures and adsorption properties were investigated. The degree of grafting and amination were increased with increasing the reaction time and had the maximum values of 138% and 1.20 mmol/g at 80 min, respectively. The initial thermal degradation temperature of PES membrane was $400^{\circ}C$. Which was reduced as the surface modification reaction had proceeded. The values of contact angle for PES membrane were decreased from 68.1 to $40.2^{\circ}$ with increasing the extent of amination, the water up-take and ion exchange capacity were also increased with increasing UV irradiation time until 80 min. The average pore size and BET surface area were decreased in order of PES, PES-g-BTCA, and aminated PES ion exchange membrane. Their average pore sizes were 624.8, 359.7, and 138.5 ${\AA}$, and their surface areas were 10.1,9.7 and 1.7 $m^2/g$, respectively.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.442-449
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• 2016

The goal of this study is to provide basic data to establish a foundation for the provision of safe drinkable water. The raw water of natural mineral water was analyzed to determine the quantities of anions (F^-, Cl^-, NO_3-N^-, and SO₄^2- ) and cations (Ca²⁺, K⁺, Mg²⁺, and Na⁺) during the former and latter half of 2016. Analysis of the current quality of the raw water of natural mineral water among domestic manufacturers showed average anions contents of 0.46mg/L of fluorine, 8mg/L of chlorine ion, 1.5mg/L of nitrate nitrogen, and 12mg/L of sulfate ion. While the fluorine content was greater than the water quality criterion of 2.0mg/L at four points, the fluorine level was overall stable. The average cations contents included 21.3mg/L of calcium, 1.0mg/L of potassium, 3.4mg/L of magnesium, and 9.6mg/L of sodium. The chemical characteristics were compared among the major ions, and the results are presented in a piper diagram. The content ratio of cations was in the order of Ca²⁺> Na⁺>Mg²⁺>K⁺, whereas that of anions was in the order of SO₄^2->Cl^->NO_3-N^->F^-. While the cations were slightly scattered, the anions were generally concentrated except for at a few points. The Ca-Na-HCO₃ type was dominant overall in water sources from diorite, gneiss, and granite, while the Na-Mg-Ca-HCO₃-Cl type was dominant in basalt sources. Mineral water manufacturers source their water under various conditions, including in-hole casing, excavation depth, and contact state of bedrock; even within the same rocky area, some differences in the water quality type can occur. When the depth of the water source was taken into account, the mean anions contents of F^-, Cl^-, NO_3-N^-, and SO₄^2- were similar, with no significant differences according to depth. Of the cations, K⁺ and Na⁺ showed no significant differences across all the tubular wells, whereas Ca²⁺ and Mg²⁺ decreased in content with depth.

• Journal of Life Science
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• v.18 no.1
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• pp.84-90
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• 2008

Bacterial colonies which were able to oxidize the manganese were isolated from six soil samples in Byungchon area. Among them, one bacterial strain was selected for this study based on its high manganese oxidation activity. This selected bacterial strain was identified as Pseudomonas sp. MN5 through physiological-biochemical test and analysis of its 16s rRNA sequence. This selected bacterial strain was able to utilize fructose and maltose, but they doesn't utilizing various carbohydrates as a sole carbon source. Pseudomonas sp. MN5 showed a very sensitive to antibiotics such as kanamycin, chloramphenicol, streptomycin and tetracycline, but a high resistance up to mg/ml unit to heavy metals such as lithium, manganese and barium. Optimal manganese oxidation condition of Pseudomonas sp. MN5 was pH 7.5 and manganese oxidation activity was inhibited by proteinase K and boiling treatment. The manganese oxidizing protein produced by Pseudomonas sp. MN5 was purified by ammonium sulfate precipitation, HiTrap Q FF anion exchange chromatography and G3000sw $_{XL}$ gel filtration chromatography. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, three manganese oxidizing protein with estimated molecular weights of 15 kDa, 46.7 kDa and 63.5 kDa were detected. Also, it was estimated that manganese oxidizing protein produced by Pseudomonas sp. MN5 were a kind of porin proteins through internal sequence and N-terminal sequence analysis.

• Journal of Life Science
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• v.25 no.7
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• pp.757-764
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• 2015

The immature fruit of Rubus coreanus Miquel (bokbunja in Korean) is mainly consumed as a fruit wine due to its sour taste and low sugar content. The lees (LBW) remaining after the production of bokbunja wine are discarded as they have no specific usage. The aim of this study was to develop high-value-added biomaterials for functional foods and beauty/health products by investigating the anti-microbial, anti-oxidant, and anti-thrombosis activities of LBW using ethanol and hot water extracts and their subsequent organic solvent fractions. The ethyl acetate (EA) fraction of LBW extracts has a high polyphenol content (413–459 mg/g), and showed strong anti-microbial activity against gram-positive bacteria. The EA fraction also showed excellent radical-scavenging activity against DPPH anion, ABTS cation, and nitrite, with strong reducing power. The polyphenol-enriched EA fraction strongly inhibited thrombin, prothrombin, and blood coagulation factors. The butanol fraction showed a specific inhibition of coagulation factors, as measured in activated partial thromboplastin time assay, which is linked to intrinsic blood coagulation. The butanol fraction also showed strong inhibition of platelet aggregation, at levels comparable to aspirin. The residue of the hot-water extract, which is produced by sequential solvent fractionation of the LBW extract, showed superior inhibition against platelet aggregation when compared to aspirin. Our results suggest that the LBW, which are currently discarded, are a promising source of novel functional foods and beauty/health products.

• Journal of Life Science
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• v.21 no.4
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• pp.576-583
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• 2011

In the course of study for the development of functional food ingredients from seaweeds having useful biological activities, the in-vitro antioxidant and nitrite scavenging activities of the methanol extracts prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta) were determined. At $500\;{\mu}g/ml$ concentration of the methanol extracts, Ecklonia cava, Ecklonia stolonifera, Eisenia bicyclis (Kjellman) Setchell, Ishige foliacea, I. okamurai, Sargassum confusum, S. fulvellum, S. yamade and Zostera marina showed 60% more DPPH and ABTS scavenging activity. The exceptions were found in I. okamurai and Z. marina, which showed 45% and 53% ABTS scavenging activity, respectively. The correlation coefficient between DPPH and ABTS scavenging activities was 0.855, suggesting that the 9 different seaweeds extracts could scavenge anion and cation radicals concurrently. In reducing power, only E.cava, E.stolonifera and E.bicyclis showed above 0.88 ($Abs_{700}$). In a while, in nitrite scavenging activity at $100\;{\mu}g/ml$ concentration of the methanol extracts, 19 different seaweeds extracts including I. foliacea, I. okamurai, S. confusum, S. fulvellum, and S. yamade showed 60% more activity. Calculation of $IC_{50}s$ of DPPH, ABTS and nitrite scavenging activities of 9 different seaweeds extracts further showed that I. foliacea and S. yamade, besides E.cava, E.stolonifera and E.bicyclis, have strong antioxidant and nitrite scavenging activity. These results suggest that the selected 9 different seaweeds could be developed as functional food ingredients and I. foliacea and S. yamade have potential as novel natural sources of antioxidant and nitrite scavenger.

• Journal of Korean Society of societal Security
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• v.4 no.2
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• pp.65-72
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• 2011

This study was carried out to investigate the cause of acidification of rainwater and to evaluate the possibility of alternative water resource in Saemangeum. The rainwater were collected in the kwangwhal-myun, Saemangeum from March to September, 2009. The collected 7 samples were analyzed with pH meter, IC (ion chromatography) and ICP (inductively coupled plasma) about the pH and the major ions ($SO{_4}^{2-}$, $NO_3{^-}$, $Cl^-$, $Ca^{2+}$, $K^+$, $NH^{4+}$, $Na^+$ and $Mg^{2+}$) of rainwater. The order of the major anion concentration and the acidification contribution in the rainwater was $SO{_4}^{2-}$>$NO_3{^-}$>$Cl^-$, and that of the major cation was $Ca^{2+}$>$K^+$>$NH_4{^+}$>$Na^+$>$Mg^{2+}$. In the initial rainwater, the major ions concentration were higher than the middle period. pH of the rainwater was the lowest at May, but similar to the results of the others. And pH of the rainwater were significant correlation with $SO{_4}^{2-}$ and $Cl^-$ in Saemangeum. From this results, the rainwater was slight acidic, and $SO{_4}^{2-}$ was the main factor contributed to the rainwater acidification in Saemangeum.

• The Journal of Korean Medicine
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• v.28 no.1 s.69
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• pp.237-248
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• 2007

Objectives : Diabetes is a disease in which the body does not produce or properly use insulin. Etiological studies of diabetes and its complications showed that oxidative stress might play a major role. Therefore, many efforts have been tried to regulate free oxygen radicals for treating diabetes and its complications. Iksujisundan has been known to be effective for the treatment of diabetes. The present study was carried out to investigate the effect of Iksujisundan on renal function, peroxynitrite(ONOO-) scavenging activity and polyol pathway in streptozotocin-induced diabetic rats. Methods : The crushed Iksujisundan was extracted 3 times, each time with 3 volumes of methyl alcohol at 60$^{\circ}C$ for 24 h. The extract was filtered and evaporated under a reduced pressure using a rotary evaporator to yield 87.8g. Iksujisundan extract was orally administreted at 100 mg per 1 kg of body weight for 20 days to the diabetic rats induced by streptozotocin(60mg/kg). The effects of Iksujisundan extract on the streptozotocin-induced diabetic rats were observed by measuring the serum level of glucose, insulin, lipid components, creatinine and BUN, and also the kidney levels of superoxide anion radical(${\cdot}$O2-), nitric oxide(NO) and ONOO-, and also the enzyme activities involved in the polyol pathway. Results : The effects of Iksujisundan on the streptozotocin-induced diabetic rats with regards to body weight, blood glucose and indulin levels, creatinine and BUN levels, total cholesterol and triglyceride lavels, and HDL-cholesterol levels were all shown to be good enough to prevent and cure the diabetes and its complications. Iksujisundan inhibited the generation of ${\cdot}$O2-,NO and ONOO- in the kidney of streptozotocin-induced diabetic rats. Renal aldose reductase and sorbitol dehydrogenase activities were increased in the streptozotocin-induced diabetic rats were reversed toward natural activities. Conclusions : Iksujisundan might inhibit the development of diabetes and its complications by scavenging reactive oxygen and nitrogen species, thereby by reducing oxidative stresses and also by regulating the activities of polyol pathway enzymes, all of which could help to recover kidney function.

• The Journal of Korean Medicine
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• v.30 no.1
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• pp.51-63
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• 2009

Objectives: Peroxynitrite ($ONOO^-$), superoxide anion radical (${\cdot}{O_2}^-$ and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging processes, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer, diabetes, obesity and atherosclerosis. The aim of this study was to investigate the $ONOO^-$, NO, ${\cdot}{O_2}^-$ scavenging and NF-${\kappa}B$ related anti-inflammatory activities of Sotosaja-hwan in ob/ob mice. Methods: Mice were grouped and treated for 5 weeks as follows. Both the normal lean (C57/BL6J black mice) and control obese (ob/ob mice) groups have received standard chow. The experimental groups were fed with a diet of chow supplemented with 30 and 90 mg Sotosaja-hwan per 1 kg of body weight for 14 days. For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4,5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Western blotting was performed using anti-phospho-$I{\kappa}B$-${\alpha}$, anti-IKK-${\alpha}$, anti-NF-${\kappa}B$ (p50, p65), anti-COX-2, anti-iNOS, anti-YCAM-1 and anti-MMP-9 antibodies, respectively. Results: Sotosaja-hwan inhibited the generation of $ONOO^-$, NO and ${\cdot}{O_2}^-$ in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondrial fraction in vitro. The generation of $ONOO^-$, NO, ${\cdot}{O_2}^-$ and PGE2 were inhibited in the Sotosaja-hwan-administered ob/ob mice groups. The GSH/GSSG ratio was decreased in the ob/ob mice, whereas the ratio was improved in the Sotosaja-hwan-administered groups. Sotosaja-hwan inhibited the protein expression levels of phospho-$I{\kappa}B$-${\alpha}$, IKK-${\alpha}$, NF-${\kappa}B$ (p50, p65), COX-2, iNOS, YCAM-1 and MMP-9 genes. Conclusions: These results suggest that Sotosaja-hwan is an effective $ONOO^-$, ${\cdot}{O_2}^-$ and NO scavenger and has NF-kB related anti-inflammatory activity in ob/ob mice. Therefore, Sotosaja-hwan might be a potential therapeutic drug against the inflammation process and inflammation-related diseases.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.4
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• pp.439-458
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• 2005

An automated analysis system for water soluble constituents in $PM_{2.5}$ has been developed. The system consists of a high capacity multi tube diffusion scrubber (MTDS), a low temperature particle impactor (LTPI), and two ion (anion and cation) chromatography (IC) systems. Atmospheric particles have been collected by passing sample air through a thermostated MTDS followed by a LTPI. This system allows simultaneous measurements of soluble ions in $PM_{2.5}$ at 30 minutes interval. At the air sampling flow rate of 1.0L/min, the detection limits of the overall system are in the order of tens of $ng/m^3$. This system has been successfully used for the measurement of particulate components of Seoul air from April 2003 to January 2004. $SO_4^{2-},\;NO_3^-,\;NH_4^+,\;NO_2^-,\;Cl^-,\;Na^+,\;K^+,\;Ca^{2+},\;and\;Mg^{2+}$ are the major ionic species for $PM_{2.5}$ at Seoul. Among them, $SO_4^{2-},\;NO_3^-\;and\;NH_4^+$ are the most abundant ions, contributed up to $86\%$ of the total and the concentrations were higher than those in any other urban sites in the world except for Chinese cities. There are high pollutant episodes which contribute about $15\~20\%$ of annual average values of the major ions. During the episode, the all parcels were transported from the asian continent and $PM_{2.5}$ were significantly neutralized. This suggests that aged and long range transported pollutants caused the high pollutant episodes. They showed a distinct daily and seasonal variations:they showed a peak in the early morning caused by the night-time accumulation of particulate matters. Atmospheric reactions including gas-to-particle reactions and inter-particle reactions and meteorological parameters including relative humidity and ambient temperature were described with related to the $PM_{2.5}$ 5 concentrations. All of the ionic species showed higher concentrations during the spring than those for summer and winter.