• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1701-1708
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• 2008

Previous investigations showed that three classes of haloaromatic compounds (HACs; chlorobenzoates, chlorophenols, and chlorobenzenes) enhanced the reductive dechlorination of Aroclor 1248, judging from the overall extent of reduction in CI atoms on the biphenyl. In the present study, we further investigated the kind of polychlorinated biphenyl (PCB) congeners involved in the enhanced dechlorination by four isomers belonging to each class (2,3-, 2,5-, 2,3,5-, and 2,4,6-chlorobenzoates; 2,3-, 3,4-, 2,5-, and 2,3,6-chlorophenols; and 1,2-, 1,2,3-, 1,2,4-, and penta-chlorobenzenes). Although the PCB congeners involved in the enhanced dechlorination varied with the HACs, the enhancement primarily involved para-dechlorination of the same congeners (2,3,4'-, 2,3,4,2'-plus 2,3,6,4'-, 2,5,3',4'- plus 2,4,5,2',6'-, and 2,3,6,2',4'-chlorobiphenyls), regardless of the HACs. These congeners are known to have low threshold concentrations for dechlorination. To a lesser extent, the enhancement also involved meta dechlorination of certain congeners with high threshold concentrations. There was no or less accumulation of 2,4,4'- and 2,5,4'-chlorobiphenyls as final products under HAC amendment. Although the dechlorination products varied, the accumulation of ortho-substituted congeners, 2-, 2,2'-, and 2,6-chlorobiphenyls, was significantly higher with the HACs, indicating a more complete dechlorination of the highly chlorinated congeners. Therefore, the present results suggest that the enhanced dechlorination under HAC enrichment is carried out through multiple pathways, some of which may be universal, regardless of the kind of HACs, whereas others may be HAC-specific.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.65-70
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• 1991

A hybrid model which uses a probabilistic model and a MLP(multi layer perceptron) model for pattern recognition of EMG(electromyogram) signals is proposed in this paper. MLP model has problems which do not guarantee global minima of error due to learning method and have different approximation grade to bayesian probabilities due to different amounts and quality of training data, the number of hidden layers and hidden nodes, etc. Especially in the case of new test data which exclude design samples, the latter problem produces quite different results. The error probability of probabilistic model is closely related to the estimation error of the parameters used in the model and fidelity of assumtion. Generally, it is impossible to introduce the bayesian classifier to the probabilistic model of EMG signals because of unknown priori probabilities and is estimated by MLE(maximum likelihood estimate). In this paper we propose the method which get the MAP(maximum a posteriori probability) in the probabilistic model by estimating the priori probability distribution which minimize the error probability using the MLP. This method minimize the error probability of the probabilistic model as long as the realization of the MLP is optimal and approximate the minimum of error probability of each class of both models selectively. Alocating the reference coordinate of EMG signal to the outside of the body make it easy to suit to the applications which it is difficult to define and seperate using internal body coordinate. Simulation results show the benefit of the proposed model compared to use the MLP and the probabilistic model seperately.

• IMMUNE NETWORK
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• 제11권5호
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• pp.281-287
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• 2011

Background: Biodegradable polymers have increasingly been recognized for various biological applications in recent years. Here we examined the immunostimulatory activities of the novel poly(aspartic acid) conjugated with L-lysine (PLA). Methods: PLA was synthesized by conjugating L-lysine to aspartic acid polymer. PLA-nanoliposomes (PLA-NLs) were prepared from PLA using a microfluidizer. The immunostimulatory activities of PLA-NLs were examined in mouse bone marrow-derived dendritic cells (BM-DCs). Results: PLA-NLs increased the number of BM-DCs when added to cultures of GM-CSF-induced DC generation on day 4 after the initiation of cultures. Examination of the phenotypic properties showed that BM-DCs generated in the presence of PLA-NLs are more mature in terms of the expression of MHC class II molecules and major co-stimulatory molecules than BM-DCs generated in the absence of PLA-NLs. In addition, the BM-DCs exhibited enhanced capability to produce cytokines, such as IL-6, IL-12, TNF-${\alpha}$ and IL-$1{\beta}$. Allogeneic mixed lymphocyte reactions also confirmed that the BMDCs were more stimulatory on allogeneic T cells. PLA- NL also induced further growth of immature BM-DCs that were harvested on day 8. Conclusion: These results show that PLA-NLs induce the generation and functional activities of BM-DCs, and suggest that PLA-NLs could be immunostimulating agents that target DCs.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.39-49
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• 2015

This study was to evaluate the growth and spatial distribution characteristics of Rhus javanica population. The study was conducted between 2015 January and July at the cut-slope revegetation site in Dae-Ji Mountain. Seeds of native species were sowed on the disturbed cut-slope in 2002. There were 119 vascular plant species 55 families and 94 genera on the cut-slope. Compositae, Rosaceae, and Leguminosae plants were dominant species, which are pioneer species in dry and barren site. Canopy of trees covered 44.1% total area, which was 8.3% increase from 2008. Rhus javanica, main species, dominated all DBH classes except DBH >24cm. Albizzia julibrissin showed high frequency in the 6~17cm DBH class and Salix koreensis was abundant at >12cm. Elaeagnus umbellata, Corylus heterophylla var. heterophylla, Alnus sibirica, and Acer pictum were not observed. Rhus javanica population was the most frequently observed on the south facing cut-slope. The average DBH of Rhus javanica was $7.3({\pm}3.7)cm$ and the average height of them was $5.2({\pm}1.7)m$. Annual average DBH growth was 7.9mm/yr and the maximum growth(12.0mm/yr) was the $3^{rd}$ year. It decreased after $6^{th}$ years. Although Rhus javanica population in the Dae-Ji Mountain was a seed originated plantation, the forest had reverse J shape diameter frequency distribution. It indicated that the forest is uneven-aged forest. The Rhus javanica population was expected to sustain.

• IMMUNE NETWORK
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• 제12권1호
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• pp.27-32
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• 2012

Background: Toll-like receptors (TLRs) have been extensively studied in recent years. However, functions of these molecules in murine B cell biology are largely unknown. A TLR4 stimulant, LPS is well known as a powerful polyclonal activator for murine B cells. Methods: In this study, we explored the effect of a murine TLR9 stimulant, M6-395 (a synthetic CpG ODNs) on B cell proliferation and Ig production. Results: First, M6-395 was much more potent than LPS in augmenting B cell proliferation. As for Ig expression, M6-395 facilitated the expression of both TGF-${\beta}1$-induced germ line transcript ${\alpha}$ ($GLT{\alpha}$) and IL-4-induced $GLT{\gamma}1$ as levels as those by LPS and Pam3CSK4 (TLR1/2 agonist) : a certain Ig GLT expression is regarded as an indicative of the corresponding isotype switching recombination. However, IgA and IgG1 secretion patterns were quite different--these Ig isotype secretions by M6-395 were much less than those by LPS and Pam3CSK4. Moreover, the increase of IgA and IgG1 production by LPS and Pam3CSK4 was virtually abrogated by M6-395. The same was true for the secretion of IgG3. We found that this unexpected phenomena provoked by M6-395 is attributed, at least in part, to its excessive mitogenic nature. Conclusion: Taken together, these results suggest that M6-395 can act as a murine polyclonal activator but its strong mitogenic activity is unfavorable to Ig isotype switching.

• 한국환경복원기술학회지
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• 제18권5호
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• pp.1-11
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• 2015

Jeju Island is managed intensively in terms of environmental and ecological aspect because of its extraordinary ecosystem types comprising numerous rare, protected flora and fauna. To depict rapid change of habitat status in Jeju Island, the InVEST Habitat Quality model has been operated and compared analytically with the Eco-Natural map. The Habitat Quality map of Jeju Island is turned out to have similar inclination with Eco-Natural map. We compared the average habitat quality value in each Eco-natural map class in Jeju Island and the habitat quality value of first second third grade and non-included area decreased as 0.95 0.76, 0.53 and 0.37 in eco natural map respectively. Compared to biodiversity map based on biological investigation, the result of the InVEST habitat quality model can be simply obtained by land cover map with threat and sensitivity data. Further studies are needed to make explicit coefficients for Jeju Island and Korean peninsula, then the Habitat Quality model could be applied to past and future scenarios to analyze extent of habitat degradation in time series to help decision makers.

• Ocean and Polar Research
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• 제33권1호
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• pp.35-43
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• 2011

Blubber plays different biological roles in cetaceans, including structural support, physiological demands (thermoregulation, streamlining, buoyancy, etc.), and energy storage. As such, biochemical composition, especially lipid, in the blubber may be vertically stratified in order to effectively assist with these functions. We analysed lipid content, class and fatty acid composition in the blubber of by-catch minke whale (Balaenoptera acutorostrata; n = 11), long-beaked common dolphin (Delphinus capensis; n = 3) and Pacific white-sided dolphin (Lagenorhynchus obiquidens; n = 2) from Korean waters. Lipid content for all three species ranged from 55 to 96% of wet weight, with a dominance of triacylglycerols. Vertical stratification of blubber lipid content was different between species. For minke whale and longbeaked common dolphin, it increased from inner (near the muscle) to outer (near the skin) layer, whereas it decreased for Pacific white-sided dolphin. Thirty-one fatty acids were found in all blubber samples and vertical stratification of fatty acid composition was similar among all three species. Among grouped fatty acids, monounsaturates were the most abundant, gradually increasing from inner to outer blubber layer, whereas polyunsaturates and saturates decreased. Such vertical stratification of lipid content and composition suggests that the modification and accumulation of lipid occur in the blubber itself in order to help cetaceans with their specific physiological needs.

• 환경영향평가
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• 제18권3호
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• pp.151-160
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• 2009

In order to use fundamental data for conservation of species diversity and stream health with dam development, fish investigation in up- and downstream of Pyeonglim Dam was seasonally conducted in 2007~2008. In addition, data of water qualities, investigated for environmental impact assessment, were used to determine a water quality standard level in Pyeonglim Stream, and it revealed that water environment condition was good in the stream. During the study period, a total number of fish caught from the 4 study sites was 5,449 representing 9 families 25 species, and there were 8 Korean endemic species (32.0%) including Rhodeus uyekii, Squalidus gracilis majimae, and Microphysogobio yaluensis. Two species of Zacco temminckii (37.5%) and Zacco platypus (26.3%) were dominant and subdominant in all sites. There were few individuals of the $2^{nd}$-class endangered species (Sand lamprey, Lampetra reissneri) and the introduced species (Bluegill, Lepomis macrochirus), found in the upstream of the dam. and further investigation for conservation of the endangered species and for prevention of the introduced species is needed in future. With fish fauna and multi-metric health assessment model in each sampling attempt, index of biotic integrity(IBI) was evaluated and it resulted mostly in good(26~35) and excellent(36~40) condition in all sites. The results indicate that it is very important to study not only environmental impact assessment with fish composition but also stream health assessment in order to conserve healthy aquatic ecosystem.

• 대한의용생체공학회:의공학회지
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• 제29권6호
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• pp.466-476
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• 2008

The more people use ambulatory electrocardiogram(ECG) for arrhythmia detection, the more researchers report the automatic classification algorithms. Most of the previous studies don't consider the un-balanced data distribution. Even in patients, there are much more normal beats than abnormal beats among the data from 24 hours. To solve this problem, the hierarchical classification using 21 features was adopted for arrhythmia abnormal beat detection. The features include R-R intervals and data to describe the morphology of the wave. To validate the algorithm, 44 non-pacemaker recordings from physionet were used. The hierarchical classification model with 2 stages on domain knowledge was constructed. Using our suggested method, we could improve the performance in abnormal beat classification from the conventional multi-class classification method. In conclusion, the domain knowledge based hierarchical classification is useful to the ECG beat classification with unbalanced data distribution.

• 대한의용생체공학회:의공학회지
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• 제37권5호
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• pp.161-167
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• 2016

Recent technological advances in sensor fabrication and bio-signal processing enabled non-constraint and non-intrusive measurement of human bio-signals. Especially, non-constraint measurement of ECG makes it available to estimate various human health parameters such as heart rate. Additionally, non-constraint ECG measurement of wheelchair user provides real-time health parameter information for emergency response. For accurate emergency response with low false alarm rate, it is necessary to discriminate quality levels of ECG measured using non-constraint approach. Health parameters acquired from low quality ECG results in inaccurate information. Thus, in this study, a machine learning based approach for three-class classification of ECG quality level is suggested. Three sensors are embedded in the back seat, chest belt, and handle of automatic wheelchair. For the two sensors embedded in back seat and chest belt, capacitively coupled electrodes were used. The accuracy of quality level classification was estimated using Monte Carlo cross validation. The proposed approach demonstrated accuracy of 94.01%, 95.57%, and 96.94% for each channel of three sensors. Furthermore, the implemented algorithm enables classification of user posture by detection of contacted electrodes. The accuracy for posture estimation was 94.57%. The proposed algorithm will contribute to non-constraint and robust estimation of health parameter of wheelchair users.