• Archives of Pharmacal Research
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• v.18 no.2
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• pp.90-99
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• 1995

The effect of protein kinase C inhibitors, sturosporine and 1-(5-isoquinolinyl sulfonyl)-2-methyl piperazine(H7) on in vitro differentiation of erythroid progenitor cells which were isolated from spleens of mice infected with the anemia-inducing strain of Friend virus were examined. Erythropoietin-mediated differentitation of erythroid progenitor cells, as determined by the incorporation of $^{59}Fe$ into protoporphyrin, was inhibited by staurosporine and H7 in a concentration -dependent manner. Scatchard analysis of the $^3H-phorbol-12$, 13-dibutyrate binding to erythroid progenitor cells revealed that at the high affinity sites the dissociation constant was 22nM and the maximum number of $^3H-phorbol-12$, 13-dibutyrate binding to erythroid progenitor cells revealed that at the high affinity sites the dissociation constant was 22nM and the maximum number of $^3H-phorbol-12$, 13-dibutyrate binding sites per cell was approximately $3.7\times10^5$. Cytosonic protein kinase C was isolated from erthroid progenitor cells and then purified by sequential column chromatogrphy. Two isoforms of protein kinase C were found. Photoaffinity labeling of the purified protein kinase C samples with $^3H-phorbol-12$12-myristate 13-acetate followed by analysis of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and autofluorography showed radiolabeled 82-KDa pepticles. Rediolabeling of the 82-KDa peptides with $^3H-phorbol-12$myristate 13-acete was almost completely blocked by excess unlabeled phorbol 12-myristate 13-acetate was almost 12-muristate 13-acetate-promoted phosphorylation with the puyrified protein kinase C samples showed that the phosphorylation of 82-KDa peptides was increased as the concentration of phorbol 12-myristate 13-acetate was increased from $10^{-8}M{\;}to{\;}10^{-4}$M. In light of the findings that erythroid progenitor cells possessed an abundance of protein kinase C and that stauroporine and H7 inhibited erythroid differentiation, it seemed likely that protein kinase C would play a role in the erythroid progenitor cell development.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.63-72
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• 2012

The main objective of this study is to assess the compatibility between Korean ministry of environment (KME) standard and ISO (KS I ISO) standard for the determination of BTEX and TPH content in soil. We carried out comparison analysis for both methods using CRM and matrix spiked samples. In case of GC-MS analysis for BTEX, we got statistically (significance level: 0.05) the same results from KME standard (ES 07600.1) and ISO standard (KS I ISO 15009). However, it showed statistically (significance level: 0.05) different results when TPH was analyzed by KME standard (ES 07552.1) and ISO standard (KS I ISO 16703). To clarify the reason why both methods produced different results for TPH content, we also did some additional experiments in terms of differences in extraction, clean-up and target hydrocarbon range. Extraction with polar and non-polar compounds mixed solvent (acetone+n-heptane) of KS I ISO 16703 showed higher extraction efficiency than with only non polar solvent (dichloromethane) extraction of ES 07552.1 by about 9%. While column type clean-up of KS I ISO 16703 showed the reduction in TPH content between before and after clean-up, batch type of clean-up of ES 07552.1 did not show any changes in TPH content through clean-up process. The target hydrocarbon range of ES 07552.1 and KS I ISO 16703 is $C_8{\sim}C_{40}$ and $C_{10}{\sim}C_{40}$, respectively. From this point of view, kerosene and JP-8 contaminated soil showed higher RPD (relative producibility deviation) values between results by both method than that of lubricant or diesel contaminated soil. The higher content of hydrocarbon ($C_8{\sim}C_{10}$) in kerosene and JP-8 played an important role in increasing RPD values in addition to the effects caused by different solvents and clean-up method. Consequently, it was concluded that both methods (ES 07552.1 and KS I ISO 16703) were not compatible.

• Explosives and Blasting
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• v.39 no.3
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• pp.15-23
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• 2021

Ventilation shafts are pathways in mines and tunnels for the removal of dust or smoke during underground space construction and operation. In mines, blasting with long blast holes is preferred for the excavation of a ventilation shaft in the 10~20m long crown pillar section. In this case, the bottom part of the blast hole is completely drilled in order to determine the drilling error, and this causes a problem of lowering the explosive charge and blasting efficiency. It is possible to solve the problem of explosive loading and to increase the blast efficiency by covering the curb of the blasthole by using stemming material. In this study, simulations for the blasting of a ventilation shaft were performed with various stemming lengths and the blasthole diameters(45, 76mm) using AUTODYN 2D SPH(Smooth particle hydrodynamics) analysis technique. Also the optimal bottom stemming column was derived by checking the size of the boulder and burden line according to blasting. Analysis result, blasting efficiency is lessened in case of stemming length less than 30cm and the optimal length of the stemming material should be 30cm or higher to achieve high efficiency of blasting.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.72-80
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• 2020

A sea dike in the Yeongsan River estuary was constructed in 1981 to supply water and reclaim tidal flats for agriculture, separating the estuary into the freshwater and seawater zones. However, the sluice gates are frequently opened and freshwater is discharged in summer when more rainfall is recorded than other seasons, then converting the estuary to brackish water system. In this study, the direct effect of freshwater discharge was investigated by monitoring daily variation in water properties and phytoplankton size structure before and after the freshwater discharge events from 2013 to 2015. Freshwater discharge resulted in a sharp decrease in salinity and dissolved oxygen (DO) at surface water whereas it increased the turbidity of water column. However, salinity did not decrease sharply in 2014 when freshwater was discharged one day before the monitoring and salinity remained low prior to the monitoring. Levels of nutrients especially dissolved inorganic nitrogen (DIN) increased after the discharge and this contributed to potential limitation of nutrients such as P or Si rather than N in the estuary. Freshwater discharge also caused the changes in phytoplankton biomass (chlorophyll a) and size structure although their responses were different between years. The changes may affect growth of grazers and thus structure of marine food web by alternating food availability in the Yeongsan River estuary.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.418-426
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• 2019

Purpose: After analyzing the seismic capability of low-rise RC grid structures with insufficient seismic performance, the purpose of the project is to install steel slab hysteretic dampers (SSHD) to improve the seismic performance of beams and columns, and to suggest measures to minimize damage to the structure and human damage when an earthquake occurs. Method: The evaluation of the seismic performance of a structure is reviewed based on the assumption that the seismic performance is identified for the grid-type subway systems that are not designed to be seismic resistant and the installation of an SSHD system, a method that minimizes construction period, if insufficient, is required. Result: After the application and reinforce of structure with SSHD, and the results of eigenvalue analysis are as follows. The natural periodicity of longitudinal direction was 0.55s and that of vertical direction was 0.58s. Conclusion: As results of cyclic load test of structure with SSHD, the shear rigidity of damper is 101%, the energy dissipation rate is 108% and, plastic rotation angle of all column and beam is satisfied for $I_o$ level and therefore it is judged that the reinforce effect is sufficient.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.527-537
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• 2018

Column tests of a sulfate reducing bacteria (SRB) bioreactor were conducted to determine the design factors for sulfate-rich mine drainage. Various substrates were applied to the bioreactor, including cow manure and its mixture with a mushroom compost, with rice straw and limestone as subsidiary materials. This procedure provided a removal efficiency of up to 82% of the total sulfur with the mixture of cow manure (70%), mushroom compost (10%) and rice straw (20%), and higher efficiencies were observed after 2 days of retention time. In the downflow condition of the flow direction, oxygen supply and re-oxidation of the sulfates occurred, causing a decrease in sulfate removal efficiency. The addition of an inorganic sludge containing heavy metals, which was intended for production of metal-sulfides in the bioreactor, had a negative effect on the long-term operation owing to arsenic release and toxicity to the SRB. The results thus show that a bioreactor using a mixed substrate with cow manure and operating in the downflow direction could reduce sulfates and total dissolved sulfur content; this process confirms the applicability of the SRB bioreactor to sulfate-rich saline drainage.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.632-641
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• 2018

Algal dynamics is controlled by multiple environmental factors such as flow dynamics, water temperature, trophic level, and irradiance. Underwater irradiance penetrating from the atmosphere is exponentially decreased in water column due to absorption and scattering by water molecule and suspended particles including phytoplankton. As the exponential decrease in underwater irradiance affects algal photosynthesis, regulating their spatial distribution, it is critical to understand the light extinction characteristics to find out the mechanisms of algal dynamics more systematically. Despite the significance, the recent data have been rarely reported in the main stream areas of large rivers, Korea. In this study, the euphotic depths and light extinction coefficients were determined by monitoring the vertical variation of underwater irradiance and water quality in the main channel of Nakdong River near Dodong Seowon once a week during summer of 2016. The average values of euphotic depth and light extinction coefficient were 4.0 m and $1.3m^{-1}$, respectively. The degree of light extinction increased in turbid water due to flooding, causing an approximate 50 % decrease in euphotic depth. Also, the impact was greater than the self-shading effect during the periods of cyanobacterial bloom. The individual light extinction coefficients for background, total suspended solid and algal levels, frequently used in surface water quality modeling, were determined as $0.305m^{-1}$, $0.090m^{-1}/mg{\cdot}L^{-1}$, $0.013m^{-1}/{\mu}g{\cdot}L^{-1}$, respectively. The values estimated in this study were within or close to the ranges reported in literatures.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.136-141
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• 2011

This study was conducted to confirm the application as ingredients of cosmetics through an examination of the function for anti-cancer and anti-microbial of the fraction isolated from Pyrus ussuriensis leaves. The dried leaf of P. ussuriensis were extracted with acetone-$H_{2}O$ (6:4, v/v), concentrated and fractionated with the upper layer of acetone on a separatory funnel. Each fraction was freeze dried, then a portion of acetone soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents and also used the MIC-gel using a series of aqueous methanol as developing solvent. The isolated compounds were identified by silica-gel TLC. The growth inhibition activity was measured using the MTT assay by the mouse meltioma (B16F10) cell. The cancer cell growth inhibition rate of fractions isolated from P. ussuriensis leaf was 80%. In anti-microbial activity test, the fraction of P. ussuriensis with 0.25 mg/disc resulted in the clear zone of 1.3 cm and 2 cm for Staphylococcus aureus and S. epidermidis of gram positive bacillus, respectively. In Escherichia coli of gram negative bacillus, the fraction with 0.5 mg/disc resulted in the clear zone of 1.1 cm~1.5 cm each fraction. From these results, we confirmed that acetate fraction of P. ussuriensis has a great potential as a natural ingredients with a anti-cancer and anti-microbial source.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.221-228
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• 2022

Major egg white proteins and their hydrolysates serve as functional food ingredients that have certain metal-chelating properties. Employing egg white proteins and their hydrolysates to scavenge dietary oxalates is anticipated to have beneficial effect in the prevention of kidney stones. The objective of this study was to determine the biogenic oxalate-chelating activity of ovalbumin, ovomucin, and ovotransferrin and their hydrolysates. To prepare oxalate extracts, 30 mL of 0.25 N HCl was added to separately to 0.5 g of dried spinach and starfruit powders followed by boiling for 15 min, and after cooling, the addition of a further 20 mL of 0.25 N HCl. Having prepared these extracts, ovalbumin, ovomucin, and ovotransferrin and their hydrolysates were separately mixed with oxalate extracts and incubated at 3℃ for 24 h. Following centrifugation, supernatants were analyzed by HPLC using a reverse-phase C18 column coupled with a diode array detector. We found that all assessed proteins and their hydrolysates showed biogenic oxalate-chelating activity against the oxalates of spinach. In contrast, however, only ovalbumin, ovalbumin-hydrolysate, and ovomucin showed chelating activity (57.10%±8.84%, 85.44%±5.30%, 73.20%±4.13%, respectively) against the oxalates of starfruit (P<0.05). Overall, hydrolyzed ovalbumin was identified as the most effective chelator of the oxalates both spinach and starfruit. In this study, we thus established that the assessed egg white proteins and their hydrolysates have oxalate-chelating activity in vitro, thereby indicating that these compounds have potential utility as nutraceuticals for the chelation of dietary oxalate. However, further research will be necessary to verify their oxalate-chelating activities against different fruits and vegetables and under specific in vivo conditions and against purified oxalate.