• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.83-91
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• 2015

Biomass burning is known to be one of the main sectors emitting greenhouse gases as well as air pollutants. Unfortunately, the inventory of biomass burning sector has not been established well. We estimated greenhouse gas (GHG) and air pollution (AP) integrated emissions from biomass burning sector in Seoul during year 2010. The data of GHG and AP emissions from biomass burning, classified into open burning, residential fireplace and wood stove, meat cooking, fires, and cremation, were obtained from Statistics Korea and Seoul City. Estimation methodologies and emission factors were gathered from reports and published literatures. Estimated GHG and AP integrated emissions during year 2010 were $3,867tonCO_{2eq}$, and 2,320 tonAP, respectively. Major sources of GHG were forest fires ($1,533tonCO_{2eq}$) and waste open burning ($1,466tonCO_{2eq}$), while those of AP were meat cooking (1,240 tonAP) and fire incidence (907 tonAP). Total emissions by administrative district in Seoul, representing similar patterns in both GHG and AP, indicated that Seocho-gu and Gangseo-gu were the largest emitters whereas Jung-gu was the smallest emitter, ranged in $2{\sim}165tonCO_{2eq}$ and 0.1~8.31 tonAP. GHG emissions per $km^2$ showed different results from total emissions in that Gwanak-gu, Jungnang-gu, Gangdong-gu and Seodaemun-gu were the largest emitters, while Seocho-gu and Gangseo-gu were near-averaged emission districts, ranged in $0.2{\sim}21tonCO_{2eq}/km^2$. However, AP emissions per $km^2$ revealed relatively minor differences among districts, ranged in $2.3{\sim}6.1tonAP/km^2$.

• Parasites, Hosts and Diseases
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• v.52 no.5
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• pp.527-529
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• 2014

This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory for necropsy. White-yellowish nodules were found in the liver of 1 of the nutrias at necropsy. Histologically, the lesions were granulomatous, and infiltrations of lipid-laden macrophages, eosinophils, and several multinucleated giant cells were observed. The lesions consisted of numerous eggs and necrotic hepatocytes. The eggs were lemon-shaped and had polar plugs at the ends of both long sides. The eggs were morphologically identified as those of C. hepatica. Worldwide, C. hepatica infection in nutrias is very rare. Nutrias are a kind of livestock, as well as wildlife; therefore, an epidemiological study for parasitic infections needs to be conducted.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.67-77
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• 2010

Stand structure and spatial associations of the dominant tree species in Quercus mongolica stands were investigated to understand interspecific relationships and the persistent dominance of Q. mongolica. We examined the species composition, DBH (diameter at breast height) distribution, and spatial distribution of trees (${\geq}\;2.5\;cm$ DBH) in two permanent $100\;m\;{\times}\;100\;m$ plots in Q. mongolica-dominant stands on the western part of Mt. Jiri. Ripley's K-function was used to characterize the spatial patterns and associations of dominant tree species. Q. mongolica showed a continuous and reverse-J shaped DBH distribution with clumped spatial distribution in both study sites. Q. mongolica and Abies koreana exhibited a negative association implying potential interspecific competition. The positive spatial association between Q. mongolica and Alnus hirsuta var. sibirica and Fraxinus sieboldiana were affected by site characteristics: limited habitat conditions with a large proportion of rock surface. Our results suggest that interactions among species were complex and ranged from positive to negative. Differences in stand and site characteristics and regeneration mechanisms among the species play an important role in regulating their spatial distribution patterns, while competition between individuals also contributes to spatial patterning of these communities. The high density and the early developmental stage of spatial distribution and structural characteristics of Q. mongolica and the relatively low importance values of other species in the stands imply that Q. mongolica will remain dominant in the study sites in the near future.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.969-975
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• 2003

Two conserved amino acid residues in the extra sugar-binding space near the catalytic site of Thermus maltogenic amylase (ThMA) were analyzed for their role in the hydrolysis and transglycosylation activity of the enzyme. Site-directed mutagenesis was carried out by replacing N33l with a lysine (N331K), E332 with a histidine (E332H), or by replacing both residues at the same time (N331K/E332H). The measured $K_m$ values indicated that affinities toward all substrates tested, including starch, pullulan, ${\beta}-cyclomaltodextrin$, and acarbose, were lower in all the mutants compared to that of wild-type ThMA, leading to reduced hydrolysis activity. In addition, the lower ratio of transglycosylation to hydrolysis in the mutants compared to that in the wild-type ThMA indicated that these mutants preferred hydrolysis to the transglycosylation reaction. These results demonstrated that the conserved dipeptide at 331 and 332 of ThMA is directly involved in the formation and accumulation of transfer products by accommodating acceptor sugar molecules.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.704-715
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• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.10
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• pp.881-884
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• 2008

In this study, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) in the composition from 51/49, was deposited on platinum for a metal-ferroelectric-metal structure. From XRD patterns, the 70 nm- and 140 nm-thick PVDF-TrFE films showed the intensity peak of near $20^{\circ}$ connected to a ferroelectric phase. Moreover, the thicker film indicated the higher intensity than thinner one. The difference of the remanent polarization (2Pr) at 0 V is decreased gradually from 10.19 to $5.7{\mu}C/cm^2$ as the thickness decrease from 140 to 70 nm. However, when the thickness decreased to 50 nm, the 2Pr rapidly drop to $1.6{\mu}C/cm^2$ so the minimum critical thickness might be at least 70 nm for device. Both different thickness films, 70 and 140 nm, indicated that the characteristic of current density-voltage was measured for $10^{-6}{\sim}10^{-7}A/cm^2$ below 15 V and the thicker film maintained relatively lower current density than thinner one. From these results, we can expect that the electrical properties for the devices particularly ferroelectric thin film transistor using PVDF-TrFE copolymer were able to be on the trade-off relationship between the remanent polarization with the bias voltage and the leakage current.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.75-76
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• 1989

The blood bank is a field of clinical pathology which requires the most accuratemaintenanceofrecording. Because the mistake in it is directly related to a patient's life. So, the computerization of the blood bank is urgent to maintain a log blook arid to compare the patient's current data with past result. We developed the blood bank management program using 32 bit minicomputer. This is composed of 4 parts; a management of routine test result, special test result, the blood issue and statistics. The management of routine test result handles the patient's information and blood typing and compares above results with the past one of same patient. The management of special test result are for special immunohematologic tests like an irregular antibody, Coombs' test, and etc. Blood issue part records the type of the blood bag, component, and the name of issuer. Statistic part are made to get statistics of each day and each month by the blood type, and the type the blood component. The program is secured by the maintenance of operator's operation history and thu provision of the security code to each operator, without which no one can enter the system and after the content. So the stability and reliability of the data is obtained. This program will be upgraded for bar-code using system in the near future.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.247-255
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• 2002

Indoor and outdoor nitrogen dioxide (NO$_2$) concentrations were measured and compared with measurements of personal exposures of 95 persons in Seoul, Korea and 57 persons in Brisbane, Australia, respectively. Time activity diary was used to determine the impact on NO$_2$ exposure assessment and microenvironmental model to estimate the personal NO$_2$ exposure. Most people both Seoul and Brisbane spent their times more than 90% of indoor and more than 50% in home, respectively. Personal NO$_2$ exposures were significantly associated with indoor NO$_2$ levels with Pearson coefficient of 0.70 (p＜0.01) and outdoor NO$_2$ levels with Pearson coefficient of 0.66 (p＜0.01) in Seoul and of 0.51 (p＜0.01) and of 0.33 (p＜0.05) in Brisbane, respectively. Using microenvironmental model by time weighted average model, personal NO$_2$ exposures were estimated with NO$_2$ measurements in indoor home, indoor office and outdoor home. Estimated NO$_2$ measurements were significantly correlated with measured personal exposures (r = 0.69, p＜0.001) in Seoul and in Brisbane (r = 0.66, p＜0.001), respectively. Difference between measured and estimated NO$_2$ exposures by multiple regression analysis was explained that NO$_2$ levels in near workplace and other outdoors in Seoul (p = 0.023), and in transportation in Brisbane (p = 0.019) affected the personal NO$_2$ exposures.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.319-324
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• 2019

This study aimed to investigate the tick species and give background for tick-borne investigations in Korea. Ticks were collected from the area within 2 km radius of the 4 domestic animal farms, where they were located in mountainous areas and raising animals on pasture, and from animal bodies in 2014 and 2015. In total, 7,973 nymphal and adult ticks were collected from the farms - 7,758 Haemaphysalis longicornis, 198 Haemaphysalis flava, and 17 Ixodes nipponensis, and 1,763 were collected from animals - 729 H. longicornis from cattle; 569 H. longicornis from goats; and 297 H. longicornis, 118 H. flava, 1 I. nipponensis, and 49 Amblyomma testudinarium from wild boars. As more species of ticks were collected from wild boars than domesticated animals and their habitats, various animal hosts should be considered while investigating tick species.

• BMB Reports
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• v.56 no.9
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• pp.482-487
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• 2023

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in niche-mediated LT-HSC maintenance. KAI1 activates TGF-β1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LT-HSCs that regulates dormancy through interaction with DARC-expressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LT-HSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia.