• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.241-246
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• 2012

Veterinary antibiotics can enter the soil ecosystem and then may be transported into groundwater via leaching process. The main aim of this study is to investigate the distribution and mobility of tetracycline, amoxicillin and sulfathiazole in soil. The adsorption of veterinary antibiotics were applied to the Freundlich adsorption isotherms. Adsorption coefficient ($K_F$) was indicated oxytetracycline > amoxicillin > sulfathiazole. Oxytetracycline concentration was highly detected in soil than in leachate. It is assumed that oxytetracycline was strongly absorbed by divalent cations such as $Ca^{2+}$ in soil. However, amoxicillin and sulfathiazole were shown higher mobility due to the lower distribution coefficient.

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.560-568
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• 1991

The simultaneous determination method which simply determined regulated pesticides was investigated. Sample was extracted with acetone-methanol and partitioned with methylene chloride after addition of saturated NaCl solution. Entract was purified by Bio-Beads S-X3 column using cyclohexane-methylene chloride (1 : 1) as eluate. The determination of pesticides was performed by BP-1 capillary column gas chromatography using ECD and NPD. The average recoveries of pesticides in rice and soy fbean were over 83% and 81%, respectively. It was possible to detect pesticides in rice up to 0.002 ppm by $\alpha-BHC$ and up to 0.05 ppm by carbaryl and in soy bean up to 0.01 ppm by ${\alpha}$-BHC and up to 0.3 ppm by carbaryl.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1212-1217
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• 2008

In this study, in order to clarify the effect of the direction of cyclic shear on the post-earthquake settlement the multi-directional shear tests were carried out for Toyoura Japan standard sand, Genkai natural sand and the Granulated Blast Furnace Slag (GBFS). In a series of tests, number of strain cycles was changed as n=5-200 and the shear strain amplitude varied from 0.1% to 1.0%. The relative density was also changed as Dr=50, 60 and 70%. From the test results for Toyoura sand and GBFS, it is clarified that the post cyclic settlement is relatively large at the small relative density and becomes large with the shear strain amplitude. When the influence of the direction of cyclic shear is decreases, the post cyclic settlement strain for Toyoura sand is converged to a constant value, but the GBFS is increased with the number of strain cycles.

• Journal of Life Science
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• v.24 no.3
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• pp.234-241
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• 2014

To identify and isolate anticancer active compounds from Solanum nigrum, S. nigrum was extracted with MeOH and then fractionated with various organic solvents ($CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$). The cytotoxic effects of the MeOH extracts from S. nigrum and its organic solvent-soluble fractions were also tested in HT29 cells. All the MeOH extracts of S. nigrum and its organic-solvent extracts induced cytotoxicity in the HT29 cells. Among the extracts, $H_2O$ was the most effective. The $H_2O$ extract was purified further by repeated silica gel, Sephadex LH-20, Diaion HP- 20, and RP-18 column chromatography. An active anticancer compound, Des-N-26-methylene-dihydrotomatidine, was isolated with a molecular weight of 416 and a molecular formula of $C_{28}H_{48}O_2$. Analysis of the cytotoxic effects of Des-N-26-methylene-dihydrotomatidine on the HT29 cells compared to those of tomatine and tomatidine are similar in its structure, is higher than tomatidine above the 40 ${\mu}g/ml$ concentration, but lower than tomatine. This is the first study to describe the anticancer activity of Des-N-26-methylene-dihydrotomatidin, isolated from S. nigrum. Des-N-26- methylene-dihydrotomatidine seems to have potential as a natural bioactive compound.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.769-779
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• 2020

This study investigates the selective fractionation of lignin with uniform structures and lower molecular weight. Lignin solubilization was first performed using a solution of acetic acid (AA) and hydrogen peroxide (HP) (4:1, (v/v)) to form peracetic acid (PAA), which is a strong oxidant. After the PAA-induced solubilization that occurred at 80℃, totally soluble lignin was extracted by ethyl acetate (EA) and divided into organic- and water-soluble fractions. The EA fraction was then fractionated by open-column using three solutions (chloroform-ethyl acetate, methanol, and water) sequentially. With an increase in the solvent polarity during the fractionation step, the molecular weight of the lignin-derived compounds in the fraction increased. Remarkably, some lignin fractions did not have aromatic structures. These fractions were identified as carboxylic acid-containing polymers like poly-carboxylates. These results conclude that the selective production of lignin-derived polymers with specific molecular weight and structural characteristics could be possible through open-column fractionation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1654-1659
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• 2010

In order to utilize squid liver by-products, which is normally discarded as industrial waste in the process of squid manufacturing, salt-fermented squid liver sauce was prepared experimentally and also tested for inhibitory activity against angiotensin converting enzyme (ACE). ACE inhibitory activity of squid liver sauce was increased with the elapse of fermentation days until 12 months, followed by a constant level of inhibitory activity thereafter. 15-month-old sauce ($IC_{50}=29.66\;{\mu}g$) was filtered through PM-10 membrane (M.W. cut-off 10,000 Da) to obtain the peptides fractions with ACE inhibition activity. Filtered fractions were applied to a Bio-gel P-2 column and three active fractions (A, B and C) were collected. Among them, fraction B applied to a SuperQ-Toyopearl 650S column chromatography lead to the isolation of active B-1 fraction. It has the ACE inhibitory activity ($IC_{50}=5.46\;{\mu}g$). The main composition of its amino acids is lysine, glycine and proline, which cover about 85% of the total amino acids.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.310-314
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• 1993

High performance liquid chromatographic method using a TSK-gel amide 80 column and isocratic elution with acetonitrile-water (63 :35 ;v/v) mixture was used for the separation and the quantitation of fructo (GF2-GF7)- and inulo-oligosaccharides (F2-F4). Retention time of each standard carbohydrate was highly reproducible. Standardization curves obtained by plotting the peak areas against the amounts of each carbohydrate showed very high coefficient of determination$({\ge}0.9884)$ and similar slopes, and a wide range of y-intercepts. Our results suggest the use of each Pure oligosaccharide for its own standardization curve instead of using a certain carbohydrate as an internal standard.

• Clean Technology
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• v.19 no.3
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• pp.295-299
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• 2013

This study was purposed and performed to evaluate removal efficiency of non-point source pollution in the process and system based on bio-retention design criteria regulated by EPA. Basic Column Reactors (BCR) were prepared for optimal determinations of inflow rate of first rainfall runoff and composition and ratio of soil layers. Removal efficiencies of non-point source pollution from synthetic runoff and real first rainfall runoff, directly sampled from motor way and parking lot, were analyzed, respectively. Removal efficiency of SS, BOD, COD, T-N, and T-P were all shown to be more than 80%.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.505-509
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• 1998

Chitinase, which is one of the pathogenesis-related proteins, was examined from Rehmannia glutinosa. Rehmannia chitinases were classified into basic and acidic groups by chitin affinity column chromatography. According to the chitinase pattern by native PAGE, basic chitinases of low Rf values were extracted more under an acidic condition (pH 2.9) than a basic condition (pH 8.8), while acidic chitinases having high Rf values were mainly detected in basic extracts. There were in total seven chitinase isoforms of three basic and four acidic isoforms in Rehmannia. The range of molecular weight of Rehmannia chitinase was from 28 to 32 kD. It showed the possibility of tissue specific expression of acidic chitinases and basic chitinases were mainly detected in root.

• Advances in nano research
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• v.10 no.1
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• pp.77-90
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• 2021

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.