• BMB Reports
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• v.39 no.2
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• pp.178-182
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• 2006

Four strains of Acidithiobacillus ferrooxidans with different iron oxidation capacity were isolated from different mine drainage stations. The 16S rRNA gene of these strains were cloned and sequenced. Based on our sequences analysis on the four strain and the data on the other strains deposited in Genbank, all A. ferrooxidans may be classified into three phylogenetic groups. The analysis data showed that nucleotide variables (signature sites) were detected in 21 positions, and most of them were found in the first 800bp from 5' terminal except position 970 and 1375. Interestingly, the first 13 signature sites were located in two main regions:the first region (position 175-234) located in V2 while the second region (position 390-439) were detected in constant region between V2 and V3. Furthermore, the secondary structure and minimal free energy were determined in two regions among strains of three groups. These results may be useful in characterizing the microevolutionary mechanisms of species formation and monitoring in biohydrometallurgical application.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1156-1163
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• 2008

We performed RT-nested PCR to study the distribution of human enteric viruses in urban rivers in Korea. During 2002-2003, water samples were collected from four rivers in Gyeonggi Province, South Korea. Among 58 samples, 45 (77.6%), 32 (55.2%), 12 (20.7%), 2 (3.4%), 4 (6.9%), and 4 (6.9%) showed positive results with adenoviruses (AdVs), enteroviruses (EVs), reoviruses (ReVs), hepatitis A viruses (HAVs), rotaviruses (RoVs), and sapoviruses (SVs), respectively. According to the binary logistic regression model, the occurrence of each enteric virus, except ReVs and HAVs, was not statistically correlated with the water temperature and levels of fecal coliforms (P<0.05). AdVs were most often detected; only 4 samples (6.9%) were negative for AdVs while positive for other enteric viruses in the studied sites. Our results indicated that monitoring human enteric viruses is necessary to improve microbial quality, and that AdVs detection by PCR can be a useful index for the presence of other enteric viruses in aquatic environments.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.722-733
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• 2013

Ground-based measurements were conducted from August 25 to September 8 of 2011 for understanding characteristics of carbonaceous aerosols measured at Gosan. Chemical components and their sources were discussed by analysis of organic compounds with identification of primary and secondary products in particulate matter. Thus, organic carbon (OC) and elemental carbon (EC) based on the carbonaceous thermal distribution (CTD), which provides detailed carbon signature characteristics relative to analytical temperature, was used to improve the carbon fractionation of the analytical method. In addition, organic compounds by gas chromatography technique with the backward trajectories were discussed for characteristics of carbonaceous aerosols. Different air-masses were classified related to the OC thermal signatures and the organic molecular markers such as aromatic acids and PAHs. We concluded that the aging process was influenced by the long-range transport from East Sea area.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.495-500
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• 2003

Tight junctions (TJ) between adjacent Sertoli cells in testis are important for the formation of the blood testis barrier (BTB). In an effort to verify the reproductive health risk of endocrine-active chemicals (EACs), changes in the transepithelial electrical resistance (TER) and the expression of TJ genes were examined by co-planar polychlorinated biphenyl (PCB) treatment in cultured mouse Sertoli cells. Although the increase in TER of Sertoli cells was accelerated by 10 nM co-planar PCB, it was downregulated by 100 nM co-planar PCB. The expression of claudin-1 was downregulated by co-planar PCB in a concentration-dependent manner. On the contrary, the expression of claudin-1 was increased in the Sertoli cells by 10 nM co-planar PCB treatment. These results suggest that the structure and function of TJ may be targeted by co-planar PCB in Sertoli cells. Assessment of the structure and function of TJ in Sertoli cells might be useful for screening the reproductive health risk of EACs.

• Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.122-129
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• 2004

Harmful Cochlodinium polykrikoides is a notorious harmful algal bloom (HAB) species that is causing mass mortality of farmed fish along the Korean coast with increasing frequency. We analyzed the sequence of the large subunit (LSD) rDNA D1-D3 region of C. polykrikoides and conducted phylogenetic analyses using Bayesian inference of phylogeny and the maximum likelihood method. The molecular phylogeny showed that C. polykrikoides had the genetic relationship to Amphidinium and Gymnodinium species supported only by the relatively high posterior probabilities of Bayesian inference. Based on the LSU rDNA sequence data of diverse dinoflagellate taxa, we designed the C. polykrikoides-specific PCR primer set, CPOLY01 and CPOLY02 and developed PCR detection assays for its sensitive, accurate HAB monitoring. CPOLY01 and CPOLY02 specifically amplified C. polykrikoides and did not cross-react with any dinoflagellates tested in this study or environmental water samples. The effective annealing temperature $(T_{p})$ of CPOLY01 and CPOLY02 was $67^{\circ}C$. At this temperature, the conventional and nested PCR assays were sensitive over a wide range of C. polykrikoides cell numbers with detection limits of 0.05 and 0.0001 cells/reaction, respectively.

• Proceedings of the KSRS Conference
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• v.1
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• pp.446-449
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• 2006

It is backscattering of solar radiation by water body that makes ocean color observable from above, either by airplanes or satellites. Given the very low direct contribution to backscattering by phytoplankton cells, it is curious why the retrieval of phytoplankton concentration from remotely observed ocean color is evidently successful. From semianalytical bio-optical models, a dataset is created of spectral absorption, scattering and backscattering coefficients as a function of chlorophyll concentration. Four scenarios are considered, 1) only molecular and no particle scattering, 2) random particle backscattering uncorrelated with chlorophyll concentration, 3) constrained random particle scattering with known backscattering ratio, and 4) constrained random scattering with random backscattering ratio. Scenario 1 only introduces moderate errors of -20% - 90%. And for scenarios 3 and 4, the errors are largely within 30% and 100%. Scenario 2 introduces the largest errors, with the retrieved chlorophyll concentration virtually uncorrelated with the true values, implying the backscattering must somehow be related to the trophic state. The results of the study suggested These 3 cases confirmed that while it is the absorption by phytoplankton that in large part decides the accuracy of chlorophyll concentration retrieval, for the success of monitoring of global ocean primary productivity we have to improve our knowledge on particle backscattering.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.83.3-84
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• 2017

On 2016 April $13^{th}$ the Jovian satellite Ganymede occulted a $7^{th}$ magnitude star. The predicted occultation track (occultation shadow) crossed the Northern Pacific Ocean, Japan, and South Korea. Hence, it was a very favorable event due to the star brightness in order to be accessible for small-aperture telescopes as well. While no other similar event is expected for the next 10 years, only two occultation events are reported in the literature in the past, from Earth in 1972 and from Voyager, in large disagreement in respect to the atmospheric detection. However, evidence of an exosphere around Ganymede was inferred through H Lyman alpha emission detected by Galileo UVS, through HST/GHRS detection of far-UV atomic O airglow emissions, signature of dissociated molecular oxygen. We organized a short-notice international coordinated occultation monitoring network with the aim to search for a signature of Ganymede's exosphere in the occultation light-curve by using facilities on Mauna Kea (NASA-IRTF) and Sobaeksan Optical Astronomy Observatory (SOAO) in South Korea.

• BMB Reports
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• v.48 no.11
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• pp.624-629
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• 2015

Lysozyme protects us from the ever-present danger of bacterial infection and binds to bacterial lipopolysaccharide (LPS) with high affinity. Beyond its role in the activation of protein C, the endothelial cell protein C receptor (EPCR) plays an important role in the cytoprotective pathway. EPCR can be shed from the cell surface, which is mediated by tumor necrosis factor-α converting enzyme (TACE). However, little is known about the effects of lysozyme on EPCR shedding. We investigated this issue by monitoring the effects of lysozyme on phorbol-12-myristate 13-acetate (PMA)-, tumor necrosis factor (TNF)-α-, interleukin (IL)-1βand cecal ligation and puncture (CLP)-mediated EPCR shedding and underlying mechanism. Data demonstrate that lysozyme induced potent inhibition of PMA-, TNF-α-, IL-1β-, and CLP-induced EPCR shedding. Lysozyme also inhibited the expression and activity of PMA-induced TACE in endothelial cells. These results demonstrate the potential of lysozyme as an anti-EPCR shedding reagent against PMA-mediated and CLP-mediated EPCR shedding.

• BMB Reports
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• v.46 no.10
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• pp.484-489
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• 2013

Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit anti-hyperlipidemic, antiplatelet and anti-melanogenic activities. Here, the anticoagulant activities of PL were examined by monitoring activated-partial-thromboplastin-time (aPTT), prothrombin-time (PT), and the activities of thrombin and activated factor X (FXa). The effects of PL on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) activated HUVECs. The results showed that PL prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. PL inhibited the generation of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, PL prolonged in vivo bleeding time and inhibited TNF-${\alpha}$ induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by PL. Collectively, our results suggest that PL possesses antithrombotic activities and that the current study could provide bases for the development of new anticoagulant agents.

• Molecules and Cells
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• v.38 no.7
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• pp.587-596
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• 2015

Obesity and diabetes arise from an intricate interplay between both genetic and environmental factors. It is well recognized that obesity plays an important role in the development of insulin resistance and diabetes. Yet, the exact mechanism of the connection between obesity and diabetes is still not completely understood. Metabolomics is an analytical approach that aims to detect and quantify small metabolites. Recently, there has been an increased interest in the application of metabolomics to the identification of disease biomarkers, with a number of well-known biomarkers identified. Metabolomics is a potent approach to unravel the intricate relationships between metabolism, obesity and progression to diabetes and, at the same time, has potential as a clinical tool for risk evaluation and monitoring of disease. Moreover, metabolomics applications have revealed alterations in the levels of metabolites related to obesity-associated diabetes. This review focuses on the part that metabolomics has played in elucidating the roles of metabolites in the regulation of systemic metabolism relevant to obesity and diabetes. It also explains the possible metabolic relation and association between the two diseases. The metabolites with altered profiles in individual disorders and those that are specifically and similarly altered in both disorders are classified, categorized and summarized.