• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2000.08a
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• pp.39-39
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• 2000

• Particle and aerosol research
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• v.8 no.1
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• pp.9-15
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• 2012

Three different commercial particle counters were used to measure the PM2.5 particles in this study. An Aerosol Spectrometer (AS) 1.109 model of Grimm and a Particle Sensor (PS) 3030 model of HCT were compared with an Aerodynamic Particle Sizer (APS) 3321 model of TSI. The responses of these instruments were compared for four sizes ($1.0{\mu}m$, $1.5{\mu}m$, $2.0{\mu}m$ and $2.5{\mu}m$) of polystyrene latex (PSL) particles and indoor air particles of the office room. The mode diameter, particle size distribution and total particle number concentration of PSL particles were measured by each instrument. In the office room, the total particle number concentration was measured for 25 minutes. In results of particle size distribution and mode diameter, the APS 3321 (52 size-channels) was more accurate than the AS 1.109 (31 size-channels) and PS-3030 (10-szie channels) since the APS has more number of size-channels than the other instruments. However, AS 1.109 and PS-3030 provided similar results of total particle number concentration to those from the APS 3321. In results of office room test, there were no significant difference from each instrument similar to results of PSL test.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3593-3599
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• 2010

In an original effort, this lab attempted to employ polystyrene nanoparticles as a template for the synthesis of ordered and highly porous macroporous $SiO_2$ thin films, utilizing their high combustion temperature and narrow size distribution. However, polystyrene nanoparticle thin films were not obtained due to the low interaction between individual particles and between the particle and silicon substrate. However, polystyrene-polyacrylic acid (PS-AA) colloidal particles of a core-shell structure were synthesized by a one-pot miniemulsion polymerization approach, with hydrophilic polyacrylic acid tails on the particle surface that improved interaction between individual particles and between the particle and silicon substrate. The PS-AA thin films were spin-coated in the thickness ranges from monolayer to approximately $1.0\;{\mu}m$. Using the PS-AA thin films as sacrificial templates, macroporous $SiO_2$ thin films were successfully synthesized by vapor deposition or conventional solution sol-gel infiltration methods. Inspection with field emission scanning electron microscopy (FE-SEM) showed that the macroporous $SiO_2$ thin films consist of interconnected air balls (~100 nm). Typical macroporous $SiO_2$ thin films showed ultralow refractive indices ranging from 1.098 to 1.138 at 633 nm, according to the infiltration conditions, which were confirmed by spectroscopy ellipsometry (SE) measurements. This research shows how the synthetic control of the macromolecule such as hydrophilic polystyrene nanopaticles and silicate sol precursors innovates the optical properties and processabilities for actual applications.

• BMB Reports
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• v.33 no.3
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• pp.249-255
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• 2000

The Haemophilus influenzae type b (Hib) has been a major cause of bacterial meningitis in children who are less than two years old. The variable (V) region repertoire of adult Caucasian antibodies (Abs) to Hib polysaccharide (PS) has been characterized well. The majority of adult antibodies against Hib uses VL that is derived from the Vk gene A2 and have arginine at the N region. In order to explore the possibility those antibody responses to Hib-PS is variable in various age groups, we examined the VL regions of the antibodies to Hib-PS in Korean adults and children. We immunized Korean adults (n = 8) and children (n = 39) with Hib tetanus conjugated vaccines, isolated RNAs from the peripheral lymphocytes, and amplified the A2-derived VL regions by RT-PCR. The PCR products were subcloned and sequenced. Forty-seven out of 54 independent clones from children used the $J{\kappa}2$, or $J{\kappa}3$ gene in preference. The adults, however, used all of the $J{\kappa}$ genes evenly. With respect to the amino acid sequences of variable regions, adult $A2-J{\kappa}$ recombinants have a germline sequence. But, the 76th codon (AGC) of child $A2-J{\kappa}2$ recombinants was substituted with CGC (arginine) in most cases (88 %) and 77 percent of child clones using the $A2-J{\kappa}3$ genes have isoleucine-109 at the junction of $J{\kappa}-C{\kappa}$ instead of threonine that is found in a germline sequence. These results suggest that the mechanism of antibody production in young children is different from that of adults.

• Journal of Environmental Science International
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• v.26 no.5
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• pp.601-608
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• 2017

The effects of elevated atmospheric $CO_2$ on growth and photosynthesis of soybean (Glycine max Merr.) were investigated to predict its productivity under elevated $CO_2$ levels in the future. Soybean grown for 6 weeks showed significant increase in vegetative growth, based on plant height, leaf characteristics (area, length, and width), and the SPAD-502 chlorophyll meter value (SPAD value) under elevated $CO_2$ conditions ($800{\mu}mol/mol$) compared to ambient $CO_2$ conditions ($400{\mu}mol/mol$). Under elevated $CO_2$ conditions, the photosynthetic rate (A) increased although photosystem II (PS II) photochemical activity ($F_v/F_m$) decreased. The maximum photosynthetic rate ($A_{max}$) was higher under elevated $CO_2$ conditions than under ambient $CO_2$ conditions, whereas the maximum electron transport rate ($J_{max}$) was lower under elevated $CO_2$ conditions compared to ambient $CO_2$ conditions. The optimal temperature for photosynthesis shifted significantly by approximately $3^{\circ}C$ under the elevated $CO_2$ conditions. With the increase in temperature, the photosynthetic rate increased below the optimal temperature (approximately $30^{\circ}C$) and decreased above the optimal temperature, whereas the dark respiration rate ($R_d$) increased continuously regardless of the optimal temperature. The difference in photosynthetic rate between ambient and elevated $CO_2$ conditions was greatest near the optimal temperature. These results indicate that future increases in $CO_2$ will increase productivity by increasing the photosynthetic rate, although it may cause damage to the PS II reaction center as suggested by decreases in $F_v/F_m$, in soybean.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.464-466
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• 2009

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.266-270
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• 1998

The identification of soil P level that exceed crop requirement is a prerequisite in implementing sustainable management of fertilizer and manure P to prevent soil and freshwater from contamination. To investigate the relationship between 0.01M $CaCl_2$ soluble P, and available P and P sorption capacity of 40 soils, P content and P sorptivity were analyzed. Single linear relationship revealed the dependence of 0.01M $CaCl_2-P$ on available P($r^2=0.479$), bioavailable P($r^2=0.281$), P sorption($r^2=-0.465$) and P absorption coefficient($r^2=-0.056^{NS}$). Thus available P as $P_2O_5$(AVP) and P sorption (PS) were most important factors in determining the concentration of 0.01M $CaC1_2-P$($CaC1_2-P$). In multinomial equation related $CaC1_2-P$ with AVP and PS, the determination coefficient was improved to 0.745. The logarithm of $CaC1_2-P$ was linearly related to AVP/PS. Consequently, the equation, $0.01M\;CaCl_2-P=0.1284e^{0.3288AVP/PS}$ could be suggested to estimate the concentration of P in 20mL of 0.01M $CaCl_2$ solution containing 2g of soil shaken for 17 hours.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.45-53
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• 2020

Background: The black soldier fly (Hermetia illucens) is gaining attention as an efficient decomposer of food waste. However, recalcitrant compounds such as plastics mixed into food waste may have negative effects on its growth and survival. Moreover, its efficiency of food waste degradation may also be affected by plastics. In addition, salt (NaCl) can also be present in high concentrations, which also reduces the efficiency of H. illucens-mediated food waste treatment. In this study, we assessed the growth of black soldier fly larvae (BSFL) reared on food waste containing polyethylene (PE) and polystyrene (PS) and NaCl. The weight of BSFL was measured every 2-4 days. Survival and substrate reduction rates and pupation ratio were determined at the end of the experiment. Results: The total larval weight of Hermetia illucens reared on food waste containing PS was greater than that of the control on days 20 and 24. However, the survival rate was lower in the group treated with 5% PS, as was substrate reduction in all PS-treated groups. The weight of BSFL reared on food waste containing PE was lower than that of the control on day 6. PE in food waste did not affect the survival rate, but the pupation ratio increased and substrate consumption decreased with increasing PE concentrations. Regardless of the plastic type, the addition of NaCl resulted in decreased larval weight and pupation ratio. Conclusions: Larval growth of black soldier fly was inhibited not by plastics but by substrate salinity. Additional safety assessments of larvae reared on food waste containing impurities are needed to enable wider application of BSFL in vermicomposting.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.72-79
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• 2013

Inactivation of the gene coding for dihydroflavonol 4-reductase (DFR) is responsible for the color difference between red and yellow onions (Allium cepa L.). Two inactive DFR-A alleles, DFR-$A^{PS}$ and DFR-$A^{DEL}$, were identified in our previous study. A functional marker was developed on the basis of the premature stop codon that inactivated the DFR-$A^{PS}$ allele. A derived cleaved amplified polymorphic sequences (dCAPS) primer was designed to detect the single nucleotide polymorphism, an A/T transition, which produced the premature stop codon. Digested PCR products clearly distinguished the homozygous and heterozygous red $F_2$ individuals. Meanwhile, to develop a molecular marker for detection of the DFR-$A^{DEL}$ allele in which entire DFR-A gene was deleted, genome walking was performed and approximately 3 kb 5' and 3' flanking sequences of the DFR-$A^R$ coding region were obtained. PCR amplification using multiple primers binding to the extended flanking regions showed that more of the extended region of the DFR-A gene was deleted in the DFR-$A^{DEL}$ allele. A dominant simple PCR marker was developed to identify the DFR-$A^{DEL}$ allele using the dissimilar 3' flanking sequences of the DFR-A gene and homologous DFR-B pseudogene. Distribution of the DFR-$A^{PS}$ and DFR-$A^{DEL}$ alleles in yellow onion cultivars bred in Korea and Japan was surveyed using molecular makers developed in this study. Results showed predominant existence of the DFR-$A^{PS}$ allele in yellow onion cultivars.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.350-355
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• 1996

Poly(AA-co-EGDMA) microgels were prepared by precipitation polymerization in highly swollen polystyrene gel solution. The polymerization was carried out in selective solvent such as cyclohexane/acetone at $60^{\circ}C$. Poly(AA-co-EGDMA) microgels with various site of $0.18{\sim}0.55{\mu}m$ were obtained from different concentration of polystyrene(PS), concentration of crosslinking agent(EGDMA), ratio of Ps/monomer and volume ratio of solvents. The particle size of poly(AA-co-EGDMA) microgels decreased with increasing the concentration of PS and increased with that of EGDMA.