• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.2
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• pp.99-104
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• 2017

Refractories used in low-rank coal gasification reactors are usually exposed in a highly corrosive $H_2S$ gas at less than $1000^{\circ}C$, and their mechanical properties such as erosion resistance and fracture strength decline with the exposure time. However, the cause of the degradation of the mechanical properties has little reported yet. In this paper, two kinds of castable refractories with different refractoriness had been exposed in a $H_2O/N_2/H_2S$ mixed gas with high $H_2S$ content for 100 hours at $900^{\circ}C$, and the changes of microstructure, crystalline phases and erosion resistance were compared before and after the corrosion test. The weight of the refractories decreases due to the elution of silica in the specimens after the corrosion test. The capillary porosities of the samples are reduced, but the erosion resistance of the samples is fatally weakened after the corrosion test. There also are changes in constituent phases; dmitryivanovite ($CaAl_2O_4$) and amorphous silica ($SiO_2$) disappear, and gypsum ($CaSO_4{\cdot}2H_2OS$) and kaolinite ($Al_2Si_2O_5(OH)_4$) newly appear after the corrosion test. It is obvious that the phase change from dmitryivanovite that works as a binding agent in the castable refractory to gypsum is the main reason of the degradation of the erosion resistance, because the mechanical properties of gypsum are much poorer than those of dmitryivanovite.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.171-178
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• 2008

In the methanol extract from safflower seeds, two kinds of antioxidant were detected by preparative HPLC [$\mu$-Bondapak $C_{18}$ column ($7.8{\times}300\;mm$)]. Two unknown compounds were defined as CA and CB which had peaks at 22.1 min and 24.5 min, respectively. Antioxidant activity was measured by their scavenging ability on the stable tree radical of 1,1-diphenly-2-picrylhydrazyl (DPPH). For bulk extraction of antioxidants, the methanol extract was fractionated with hexan, chloroform, ethyl acetate and butanol. The ethyl acetate traction showing the highest DPPH radical scavenging activity was further purified by silica gel column chromatography to CA and CB. By NMR analysis, CA and CB were identified as N-(p-Coumaroyl)serotonin and N-feruoylserotonin, respectively. The content of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were analyzed by reverse phase HPLC using a $\mu$-Bondapak $C_{18}$ column ($3.9{\times}300\;mm$) with linear gradient elution from 10% acetonitrile to 50% acetonitrile for 30min on UV detector at 300 nm. The contents of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were 4.11 mg/g DW and 7.29 mg/g DW, respectively, and these two DPPH radical scavengers were detected only in the hull of seeds.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.2
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• pp.168-173
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• 2015

Bangpungtongseong-san(BPTSS, Fangfengtongsheng-san in Chineses) is a traditional herbal formula comprising 18 medicinal herbs. In the present study, we performed the simultaneous analysis for four compounds of BPTSS and examined anti-allergic effects in human keratinocytes and mouse splenocytes. The column for separation of four compounds was used Luna C18 column and maintained at 40℃. The mobile phase for gradient elution consisted of two solvent systems. The analysis was carried out at a flow rate of 1.0 mL/min with PDA detection at 254 and 280 nm. To evaluate production and expression of Th2 chemokines, ELISA and RT-PCR were conducted in tumor necrosis factor (TNF)-α and interferon (IFN)-γ-stimulated HaCaT cells with or without BPTSS or silymarin, a positive control for skin inflammation. To measure Th2 cytokines, primary mouse splenocytes were treated with BPTSS and performed ELISA for interleukin (IL)-4, 5, 13. Calibration curves were acquired with r2>0.9999. The contents of geniposide, liquiritin, baicalin, and glycyrrhizin in BPTSS were 5.06 ㎎/g, 7.33 ㎎/g, 27.56 ㎎/g, and 7.81 ㎎/g, respectively. BPTSS reduced TARC and RANTES production and mRNA expression in TNF-α and IFN-γ-treated HaCaT cells. BPTSS inhibited IL-4, 5, and 13 production in mouse splenocytes. Our data will be a helpful information to upgrade quality control and anti-allergic effects of BPTSS.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.35-41
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• 2006

This paper analyzed elution and ingredients of soil components which consist of soil and rocks in 6 regions in Yeongyang and Cheongsong to identify substantial matters that cause muddy water in Imha reservoir. We identified that more than 80% of major ingredients in collected soil and rocks are vermiculite(V), illite(I), kaolinite(Ka), quartz(Q), feldspar(F). Sodium and calcium are eluted in large quantities from soil of Sanseong and Cheongki. When calcium is in contact with water, much ions are eluted rapidly. We confirmed these ions are alkali minerals rising pH. We consider clay components distributed in Yeongyang as major cause of muddy water and rising pH of Imha reservoir because its ingredient calcite easily is dissolved in rainwater and splits other mineral particles into ${\mu}m$ sized particles.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.160-166
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• 2015

Yijung-tang (YJT) is a traditional herbal formula comprising 4 medicinal herbs. In the present study, we performed the simultaneous analysis for three compounds of YJT and examined anti-allergic effects in vitro. The column for separation of three compounds was used Gemini C18 column and maintained at 40$^{\circ}C$. The mobile phase for gradient elution consisted of two solvent systems. To evaluate Th2 chemokines, YJT was treated into tumor necrosis factor (TNF)-${\alpha}$ and interferon (IFN)-${\gamma}$-stimulated HaCaT cells, and performed ELISA for thymus and activation regulated chemokine (TARC) and regulated on activation, normal T-cell expressed and secreted (RANTES). To measure Th2 cytokines, YJT was added into primary mouse splenocytes, and performed ELISA for interleukin (IL)-4, 5, 13. Calibration curves were acquired with r² >0.9999. The contents of liquiritin, glycyrrhizin, and 6-gingerol in YJT were 4.50 mg/g, 11.10 mg/g, and 1.33 mg/g, respectively. YJT inhibited production of TARC and RANTES in TNF-${\alpha}$ and IFN-${\gamma}$-treated HaCaT cells. YJT also reduced production of IL-4, 5, and 13 in primary mouse splenocytes. In conclusion, our data will be a valuable information to improve quality control and anti-allergic effects of YJT.

• Archives of Plastic Surgery
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• v.49 no.2
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• pp.258-265
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• 2022

Background Chitosan (CS) is a well-known antimicrobial dressing material. Moreover, widely used amniotic membranes contain growth factors beneficial for wound healing. Herein, we created a novel amnion-conjugated CS-alginate membrane dressing and tested its wound healing potency in a diabetic swine model. Methods The bovine amniotic powder growth factor contents were evaluated by protein assay, and the powder's wound healing effects were assessed in vitro by HaCaT cell scratch closure. In vivo, two minipigs developed streptozotocin-induced diabetes. Serial serum glucose measurements and intravenous glucose tolerance tests were performed to confirm their diabetic status. Twelve square-shaped wounds created on each pig's back were randomly divided into control (n = 4), CS (n = 4), and amnion-CS (AC; n = 4) groups and treated accordingly with different dressings. Wound healing in each group was assessed by measuring wound contraction over time, capturing wound perfusion with indocyanine green (ICG) angiography, and histologically analyzing inflammatory markers. Results Amniotic powder elution promoted HaCaT cell migration in the scratch wound model, suggesting its beneficial in vitro wound healing effects. In vivo, the CS and AC groups showed earlier wound contraction initiation and reepithelialization and earlier wound perfusion improvement by ICG angiography than the control group. Additionally, the wound size of the AC group at week 3 was significantly smaller than those in the control group. There was no significant difference in the numbers of acute and chronic inflammatory cells between the groups. Conclusion The amnion-conjugated CS-alginate membrane, as well as CS dressing alone, could be a favorable dressing option for diabetic wounds.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.361-370
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• 1980

Distribution coefficients of various elements with the strong acidic caion-exchanger, Dowex 50W-x8, 100∼200 mesh were investigated in various concentrations of succinic, hydrochloic acid and it's mixture. Based on these distribution coefficients,the experimental condition for their quantitative separation of those elements is established in 0.9 M hydrochloric acid as eluent, several examples of successful separations are described and the dependence of distribution coefficients on ionic radius is also discussed.

• Resources Recycling
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• v.11 no.2
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• pp.14-19
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• 2002

PVC sheet was treated in O~10M NaOH solutions at $80~150^{\circ}C$ for O~7 hour, in order to study the leaching phenomena of plasticizer. The yield of phthalic acid produced by hydrolysis of DOP was increased greatly with increasing temperature and NaOH concentration by accelerating of alkali catalyst. The yield of phthalic acid was reached ca. 100% in 10M NaOH at $150^{\circ}C$ over 3 hours. Therefore, the plasticizer containing 30% in PVC sheet could be hydrolyzed in alkali solutions before the occurrence of dehydrochlorination. Besides, in the thermal reaction, the pores were produced in the PVCsheet by the hydrolysis of DOP.

• Journal of Microbiology
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• v.45 no.1
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• pp.48-52
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• 2007

A new procedure for the concentration of nonoviruses from water samples has been developed. This procedure (calcium flocculation-citrate dissolution method) uses the following steps: virus flocculation formed by treatment with 1 M $CaCl_2$ and 1 M $Na_2HPO_4$, virus release by sodium citrate dissolution (0.3 M Na citrate, pH 3.5), and virus re-concentration by ultrafiltration. When reverse transcription (RT)-PCR was performed after the procedure, the overall detection sensitivity for seeded noroviruses in a one liter drinking water sample was as low as 1 RT-PCR unit, which is equal to a $10^{-6}$ dilution of the virus sample. This approach showed at least a 5-fold-higher sensitivity than the current method with its three steps of adsorption-elution-concentration. The newly developed procedure was used to test different brands of bottled drinking water from China for putative contamination with noroviruses. A total of 144 samples were analyzed; all of the samples were negative for norovirus specific nucleic acids.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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• pp.744-749
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• 2008

The properties of the polymer-modified mortars are influenced by the polymer film, cement hydrates and the combined structure between the organic and inorganic phases. Also, this quality of polymer modified cement strongly depend on weather condition and polymer cement ratio. To overcome this problem, polymer-modified cement were prepared by varying polymer/cement mass ratio (P/C) with $0{\sim}20%$ and constant water/cement mass ratio of 0.5. The effect of polymer on the hydration of this polymer cement is studied on different polymer cement ratio. The results showed that the polymer cement paste have increased the viscosity in addition the amount of polymer dosage and the polymers is completed resulting in a reduced degree of hydration caused by different ion elution amount. Also we know that the reactants is calcium acetate as a results of chemical reaction between acetate group in EVA which is hydrolysis in water and $Ca^{2+}$ ion during hydration of cement.