• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.262.1-262.1
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• 2014

Lipid peroxidation induces functional deterioration of cell membrane and induces cell death in extreme cases. These phenomena are known to be related generally to the change of physical properties of lipid membrane such as decreased lipid order or increased water penetration. Even though the electric property of lipid membrane is important, there has been no report about the change of electric properties after lipid peroxidation. Herein, we demonstrate the molecular energy band change in red blood cell membrane through peroxidation by air-based atmospheric pressure DBD plasma treatment. Ion-induced secondary electron emission coefficient (${\gamma}$ value) was measured by using home-made gamma-focused ion beam (${\gamma}$-FIB) system and electron energy band was calculated based on the quantum mechanical Auger neutralization theory. The oxidized lipids showed higher gamma values and lower electron work functions, which implies the change of surface charging or electrical conductance. This result suggests that modified electrical properties should play a role in cell signaling under oxidative stress.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.577-585
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• 2014

A series of experiments using atmospheric-pressure non-thermal plasma coupled with transition metal catalysts were performed to remove ethylene from agricultural storage facilities. The non-thermal plasma was created by dielectric barrier discharge, which was in direct contact with the catalyst pellets. The transition metals such as Ag and $V_2O_5$ were supported on ${\gamma}-Al_2O_3$. The effect of catalyst type, specific input energy (SIE) and oxygen content on the removal of ethylene was examined to understand the behavior of the hybrid plasma-catalytic reactor system. With the other parameters kept constant, the plasma-catalytic activity for the removal of ethylene was in order of $V_2O_5/{\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ from high to low. Interestingly, the rate of plasma-catalytic ozone generation was in order of $V_2O_5/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$, implying that the catalyst activation mechanisms by plasma are different for different catalysts. The results obtained by varying the oxygen content indicated that nitrogen-derived reactive species dominated the removal of ethylene under oxygen-lean condition, while ozone and oxygen atoms were mainly involved in the removal under oxygen-rich condition. When the plasma was coupled with $V_2O_5/{\gamma}-Al_2O_3$, nearly complete removal of ethylene was achieved at oxygen contents higher than 5% by volume (inlet ethylene: 250 ppm; gas flow rate: $1.0Lmin^{-1}$; SIE: ${\sim}355JL^{-1}$).

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.356-362
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• 2010

Ceramide is important not only for the maintenance of the barrier function of the skin but also for the water-binding capacity of the stratum corneum. Although the exact role of ceramide in the human skin is not fully understood, ceramide has become a widely used ingredient in cosmetic and pharmaceutical industries. Compared with other microorganisms, yeast is more suitable for the production of ceramide because yeast grows fast and is non-toxic. However, production of ceramide from yeast has not been widely studied and most work in this area has been carried out using Saccharomyces cerevisiae. Regulating the genes that are involved in sphingolipid synthesis is necessary to increase ceramide production. In this study, we investigated the effect of the genes involved in the synthesis of ceramide, lcb1, lcb2, tsc10, lac1, lag1, and sur2, on ceramide production levels. The genes were cloned into pYES2 high copy number vectors. S. cerevisiae was cultivated on YPDG medium at $30^{\circ}C$. Ceramide was purified from the cell extracts by solvent extraction and the ceramide content was analyzed by HPLC using ELSD. The maximum production of ceramide (9.8 mg ceramide/g cell) was obtained when the tsc10 gene was amplified by the pYES2 vector. Real-time RT-PCR analysis showed that the increase in ceramide content was proportional to the increase in the tsc10 gene expression level, which was 4.56 times higher than that of the control strain.

• IMMUNE NETWORK
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• v.10 no.2
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• pp.46-54
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• 2010

Background: Graft-versus-host disease (GVHD) is initiated when alloreactive donor T cells are primed by host APCs to undergo clonal expansion and maturation. Since there is a controversy regarding the role of nonhematopoietic cells in GVHD, we wanted to investigate the influence of MHC disparity on nonhematopoietic cells on the pathogenesis of GVHD in the MHC-haplomismatched C57BL/6 ($H-2^b$) or DBA/2 $(H-2^b){\rightarrow}$unirradiated ($C57BL/6{\times}DBA/2$) $F_1(BDF_1;\;H-2^{b/d})$ murine model of acute GVHD (aGVHD) or chronic GVHD (cGVHD). Methods: We generated ($BDF_1{\rightarrow}C57BL/6$), ($BDF_1{\rightarrow}DBA/2$), and ($BDF1{\rightarrow}BDF_1$) chimeras and examined GVHD-related parameters and donor cell engraftment in those chimeras. Results: Using this experimental system, we found that 1) severe aGVHD across MHC Ag barrier depends on the expression of nonhematopoietically rather than hematopoietically derived alloAgs for maximal GVHD manifestations; 2) host APCs were sufficient to break B cell tolerance to self molecules in cGVHD, whereas host APCs were insufficient to induce autoimmunity in aGVHD; 3) donor cell engraftment was greatly enhanced in the host with MHC-matched nonhematopoietic cells. Conclusion: Taken together, our results provide an insight into how MHC disparity on GVHD target organs contribute to the pathogenesis of GVHD.

• Journal of Photoscience
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• v.9 no.2
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• pp.29-32
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• 2002

Studies till date suggest the existence of a fetal biological clock in suprachiasmatic nuclei entrained by the circadian signal from mother. Melatonin from maternal pineal gland reaches to the fetus by crossing every biological barrier including placenta, hence fetuses were exposed to similar melatonin variation as their mother. Experimental modulations of maternal pineal gland activity of pregnant females either by exposing the them to different photoperiodic schedules or by exogenous melatonin treatments till the date of parturition, regulated the fetal plasma level of melatonin, thereby the prenatal (fetal) growth and development. This clearly suggests the maternal transport of melatonin to their fetus through placenta since fetal retina-hypothalamic tract was incomplete. An extension of experimental schedules till 60 days of post-partum period regulated the neonatal pineal gland activity and gonadal maturation along with their plasma levels of melatonin and sex steroids suggesting clearly the phenomenon of maternal transfer of melatonin to their young ones during the post-natal period, when the neonates were solely dependent on the mother's milk for their nutrition and energetic demands. On the basis of above observations we may suggest that the maternal pineal gland activity regulate the prenatal development by passing its melatonin to fetus via placenta and post-natal growth and sexual maturation by passing maternal melatonin to neonates via milk. Hence, the photoperiod perceived by mother is translated into the maternal plasma level of melatonin which not only regulates the prenatal but also the post-natal growth and sexual maturation of neonates.

• Journal of the korean society of oceanography
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• v.37 no.4
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• pp.224-231
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• 2002

Vertical distributions of coprostanol (5$\beta$-cholestan-3$\beta$-ol) and other sterols were investigated in the intertidal sediment of Shinbul island in the Han River estuary to estimate the short-term variations of fecal contamination in association with reclamation activity which caused a construction of tidal barrier and emigration of residents from the island. Quantitative contributions of coprostanol in total sterol (9.87-15.84%) and in total organic carbon (82.0-157.7 $\mu\textrm{g}$ g$^{-1}$ OC) implied that a substantial amount of organic matter associated with fecal pollutants was introduced into the sediment. The highest contribution of coprostanol to organic carbon that was observed between 0.3-0.9 cm depth seemed to be associated with increased human activities for the reclamation project of the island. The ratio of coprostanol to organic carbon decreased within 0.3 cm depth, which indicated decreased fecal contamination after the emigration of residents from the island. The results suggested that measurement of coprostanol could relevantly reflect short-term fluctuation of fecal contamination in the sediment of the Han River estuary.

• Journal of Korean Biological Nursing Science
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• v.20 no.3
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• pp.169-176
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• 2018

Purpose: This study was performed to elucidate whether the obesity or body image is a barrier to breast screening compliance in Korean women. Methods: We included 54,017 women aged between 35 to 70 years from the Korea Community Health Survey (KCHS) 2014 dataset. To identify whether a mutual relationship exists between weight perceptions and breast cancer screening rates, the participants were divided into three groups according to the level of concordance between Body Mass Index (BMI) and a subjective body image. Descriptive analyses, a chi-square test, and multivariate logistic regression analyses were performed. Results: After covariate adjustment, the screening rate of the overweight group was 1.09 times higher than the normal weight group (odds ratio [OR], 1.09; confidence interval [CI], 0.00-0.16; p= .038) and the severe obesity group was 1.20 times lower (OR, 0.83; CI, -0.36-0.00; p= .047). Weight misperception also had a significant influence on breast cancer screening. Especially, The overweight distortion group was less likely to undergo breast cancer screening (OR, 0.93; CI, -0.15-0.00; p= .037). Conclusion: Obesity and weight misperceptions are associated with lower compliance with breast cancer screening guidelines.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.41-45
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• 2007

Polaromonas naphthalenivorans CJ2, responsible for naphthalene degradation at a coal tar contaminated site, was isolated on MSB agar media supplied with naphthalene vapor as the sole carbon source at $10^{\circ}C$. The strain is not isolated under the same isolation condition using the same soil sediment at $20^{\circ}C$ although its optimum temperature is about $20^{\circ}C$. In this work we explored the reason why strain CJ2 could not have been isolated on MSB agar with naphthalene vapor at $20^{\circ}C$. Dispersed CJ2 cells in PBS buffer formed colonies on MSB agar with naphthalene vapor at $10^{\circ}C$ with low naphthalene vapor pressure, but not at $20^{\circ}C$ with high naphthalene vapor pressure. However, streaked cells without resuspension grew on MSB agar with naphthalene vapor at $10^{\circ}C,\;20^{\circ}C$, and even $25^{\circ}C$. Investigation of scanning electron microscopy showed that CJ2 cells formed extracellular polysaccharide (EPS) capsules, which were released easily from CJ2 cells by just dispersion. Therefore, it is concluded that strain CJ2 is able to overcome the naphthalene toxicity by forming a capsule-type barrier around the cells although it is susceptible to naphthalene toxicity at high temperature.

• ALGAE
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• v.31 no.2
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• pp.91-103
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• 2016

A goal of phylogeography is to relate phylogenetic patterns to potential historic and contemporary geographic isolating events. Genetic breaks found in phylogeographic studies may denote boundaries between more generally applicable biogeographic regions. We investigated the distribution of Lessonia variegata, an important habitat forming alga, found on most rocky shores around New Zealand’s main islands, plus related species from surrounding waters. L. variegata has been shown to consist of four distinct cryptic species. Our aim was to compare the distribution of L. variegata with proposed bioregions; and to develop phylogeographic hypotheses to explain its present day distribution. Both a mitochondrial (atp8-sp) and plastid (RuBisCo spacer) marker, with different mutation rates, were used to gain information of the phylogenetic history of Lessonia. The data revealed high phylogeographic structuring and reciprocal endemism for all L. variegata cryptic species. One species (L. variegata / N) is confined to the northern part of the North Island of New Zealand; L. variegata / W is found at the southeast of the North Island and the northern South Island; L. variegata / K is endemic to the northeast South Island; and L. variegata / S is restricted to the southern part of the South Island. No overlapping areas of L. variegata species distribution were found. The data showed that genetic breaks in Lessonia do mostly correlate to bioregions, and highlight the importance of Cape Campbell at the northeast of the South Island and East Cape in the North Island, well known phylogeographic breaks, as a barrier between adjacent species.

• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.27-34
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• 2012

Soy protein isolate (SPI)-based edible coating, with and without carboxymethyl cellulose (CMC), were used to reduce oxidative degradation of cut pork stored at $4^{\circ}C$ for 5 days. The SPI coating reduced (p<0.05) thiobarbituric acid-reactive substances (TBARS) and peroxide value (PV), compared with controls. The inhibition of TBARS and PV for SPI-coated porks with and without CMC, compared with the control was 19.1 and 23.9, and 25.7 and 37.7%, respectively. The SPI coating prevented loss of $L^*$ and $a^*$ values of porks compared to the control. The ability of the SPI coating to provide a moisture barrier for the porks was reduced (p<0.05). The SPI-coated porks with and without CMC reduced moisture loss by 37.3 and 44.6%, respectively, over the control. However, SPI coating of porks did not inhibit the growth of either total plate counts or L. monocytogenes. The result revealed that SPI can effectively be used as a natural antioxidative coating to extend quality and shelf life of pork.