• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.620-627
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• 2004

On the foundation of a database of genome sequences and protein analyses, the ability to clone a gene based on a peptide analysis is becoming more feasible and effective for identifying a specific gene and its protein product of interest. As such, the current study conducted a protein analysis using 2-D PAGE followed by MALDI- TOF and ESI-MS to identify a highly expressed gene product of C. parasitica. A distinctive and highly expressed protein spot with a molecular size of 47.2 kDa was randomly selected and MALDI-TOF MS analysis was conducted. A homology search indicated that the protein appeared to be a fungal enolase (enol). Meanwhile, multiple alignments of fungal enolases revealed a conserved amino acid sequence, from which degenerated primers were designed. A screening of the genomic $\lambda$ library of C. parasitica, using the PCR amplicon as a probe, was conducted to obtain the full-length gene, while RT-PCR was performed for the cDNA. The E. coli-expressed eno 1 exhibited enolase enzymatic activity, indicating that the cloned gene encoded the C. parasitica enolase. Moreover, ESI-MS of two of the separated peptides resolved from the protein spot on 2-D PAGE revealed sequences identical to the deduced sequences, suggesting that the cloned gene indeed encoded the resolved protein spot. Northern blot analysis indicated a consistent accumulation of an eno1 transcript during the cultivation.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.929-935
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• 2002

The 5-stage biological nutrient removal (BNR) process with step feed system showed a very stable organic carbon and nutrient removal efficiency ($87\%\;COD\,;79\%\;nitrogen,\;and\;87\%$ phosphorus) for an operation period of 2 years. In each stage at the pilot plant, microbial communities, which are important in removing nitrogen and phosphorus, were investigated using fluorescence in-situ hybridization (FISH) and 165 rDNA characterization. All tanks of 5-stage sludge had a similar composition of bacterial communities. The totat cell numbers of each reactor were found to be around $2.36-2.83{\times}10^9$ cells/ml. About $56.5-62.0\%$ of total 4,6-diamidino-2-phenylindol (DAPI) cells were hybridized to the bacterial-specific probe EUB388. Members of ${\beta}$-proteobacteria were the most abundant proteobacterial group, accounting for up to $20.6-26.7\%$. The high G+C Gram-positive bacterial group and Cytophaga-Flexibacter cluster counts were also found to be relatively high. The beta subclass proteobacteria did not accumulate a large amount of polyphosphate. The proportion of phosphorus-accumulating organisms (PAOs) in the total population of the sludge was almost $50\%$ in anoxic-1 tank. The high G+C Gram-positive bacteria and Cytophaga-Flexibacter cluster indicate a key role of denitrifying phosphorus-accumulating organisms (dPAOs). Both groups might be correlated with some other subclass of proteobacteria for enhancing nitrogen and phosphorus removal in this process.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.426-430
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• 2008

We report clinical, cytogenetic, and fluorescence in situ hybridization (FISH) studies of a patient with ring chromosome 9. She presented with failure to thrive, facial dysmorphysm and mild psychomotor development delay in the absence of major malformations. Peripheral blood karyotype of the patient was 46,XX,r(9)(p24q34). G-band analysis suggested no loss of material in the ring chromosomes. FISH analysis using the subtelomere-specific sequences on chromosome 9p and 9q, revealed 46,XX,r(9)(p24q34),ish r(9)(D9S913-,D9S325+). Failure to detect any hybridization of a probe for the subtelomeric sequences in the ring 9p terminal suggested that this ring arose from breakage in the distal short arm. The cytogenetic and FISH data in our case provided further evidence for the existence of a "complete ring" phenotype with incomplete subtelomeric sequences.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.3
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• pp.120-125
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• 2002

The switching-mode power converter has been widely used because of its features of high efficiency and small weight and size. These features are brought by the ON-OFF operation of semiconductor switching devices. However, this switching operation causes the surge and EMI(Electromagnetic Interference) which deteriorate the reliability of the converter themselves and entire electronic systems. This problem on the surge and noise is one of the most serious difficulties in AC-to-DC converter. In the switching-mode power converter, the output voltage is generally controlled by varying the duty ratio of main switch. When a converter operates in steady state, duty ratio of the converter is kept constant. So the power of switching noise is concentrated in specific frequencies. Generally, to reduce the EMI and improve the immunity of converter system, the switching frequency of converter needs to be properly modulated during a rectified line period instead of being kept constant. Random Pulse Width Modulation (RPWM) is performed by adding a random perturbation to switching instant while output-voltage regulation of converter is performed. RPWM method for reducing conducted EMI in single switch three phase discontinuous conduction mode boost converter is presented. The more white noise is injected, the more conducted EMI is reduced. But output-voltage is not sufficiently regulated. This is the reason why carrier frequency selection topology is proposed. In the case of carrier frequency selection, output-voltage of steady state and transient state is fully regulated. A RPWM control method was proposed in order to smooth the switching noise spectrum and reduce it's level. Experimental results are verified by converter operating at 300V/1kW with 5%~30% white noise input. Spectrum analysis is performed on the Phase current and the CM noise voltage. The former is measured with Current Probe and the latter is achieved with LISN, which are connected to the spectrum analyzer respectively.

• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.100-104
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• 2007

A protocol for the production of transgenic Panax ginseng C.A. Meyer was established via Agrobacterium tumefaciens-mediated genetic transformation of direct somatic embryos. A number of conditions related to the co-cultivation were tested with respect to maximizing transformation efficiency. The results showed that pH of the co-cultivation medium (5.7), the bacterial growth phase (optical density; $OD_{600}$ = 0.8), co-cultivation period (3 days), and acetosyringone concentration $(100\;{\mu}M)$ had positive effects on transformation. Selected plantlets were cultured on the medium at an elevated hygromycin level(30 mg/l). Integration of the transgenes into the P. ginseng nuclear genome was confirmed by PCR analysis using hpt primers and by Southern hybridization using hpt-specific probe. The transgenic plantlets were obtained after 3-month cultivation and did not show any detectable variation in morphology or growth characteristics compared to wild-type plants.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2283-2287
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• 2007

Amyloid fibril formation of amyloid β/A4 protein (Aβ) is critical to understand the pathological mechanism of Alzheimer's disease and develop controlling strategy toward the neurodegenerative disease. For this purpose, dequalinium (DQ) has been employed as a specific modifier for Aβ aggregation and its subsequent cytotoxicity. In the presence of DQ, the final thioflavin-T binding fluorescence of Aβ aggregates decreased significantly. It was the altered morphology of Aβ aggregates in a form of the bundles of the fibrils, distinctive from normal single-stranded amyloid fibrils, and the resulting reduced β-sheet content that were responsible for the decreased fluorescence. The morphological transition of Aβ aggregates assessed with atomic force microscope indicated that the bundle structure observed with DQ appeared to be resulted from the initial multimeric seed structure rather than lateral association of preformed single-stranded fibrils. Investigation of the seeding effect of the DQ-induced Aβ aggregates clearly demonstrated that the seed structure has determined the final morphology of Aβ aggregates as well as the aggregative kinetics by shortening the lag phase. In addition, the cytotoxicity was also varied depending on the final morphology of the aggregates. Taken together, DQ has been considered to be a useful chemical probe to control the cytotoxicity of the amyloid fibrils by influencing the seed structures which turned out to be central to develop therapeutic strategy by inducing the amyloid fibrils in different shapes with varied toxicities.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.707-714
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• 2017

There have recently been an increasing number of reports claiming that the periodontal disease, the most typical oral disease, is closely associated with various systemic diseases such as cardiovascular disease. Therefore, it is imperative to explore the methods that can ensure effective and cost-effective monitoring of periodontal disease in specific population groups, as well as individuals in the electronic medical record environment. However, traditional periodontal examination methods, such as periodontal probe, are considerably demanding and time-consuming for dental specialists, and furthermore, cause the risk of bacteremia as they are invasive procedures. Thus, the objective of this study was to validate the capability of new method for screening the periodontal disease using the self-reported questionnaire for periodontitis which is the non-invasive procedure to replace radiography.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.393-399
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• 2004

Useful genes can be Screened from various environments by construction of metagenomic DNA libraries. In this study, water samples were collected from several lakes in mid Korea, and analyzed by T-RFLP to examine diversities of the microbial communities. The crude DNAs r were extracted by the SDS-based freezing-thawing method, and then further purified using an $UltraClean^{TM}$ kit (MoBio, USA). The metagenomic libraries were constructed with the DNAs partially digested with EcoR I, BamH I, and Sac II in Escherichia coli DH 10B using the pBACe3.6 vector. About 44.0 Mb of metagenomic libraries were obtained with average inserts 13-15 kb in size. The bphC genes responsible for degradation of aromatic hydrocarbons via mets-cleavage were identified from the metagenomic libraries by colony hybridization using the bphC specific sequence as a probe. The 2,3-dihydroxybiphenyl (2, 3-DHBP) dioxygenase gene (bphC ), capable of degradation of 2,3-DHBP, was cloned and its nucleotide Sequences analyzed. The genes consisted of 966 and 897 base pairs with an ATG initiation codon and a TGA termination codon. The activity of the 2,3-DHBP dioxygenase was highly expressed to 2,3-DHBP and Showed a broad substrate range to 2,3-DHBP, catechol, 3-methylcatechol and 4-methylcatechol. These results in-dicated that the bphC gene identified from the metagenomes derived from lake water might be useful in the development of a potent strain for degradation of aromatic pollutants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1024-1030
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• 1996

Capsaicin (8-methyl-N-vanillyl-6-nonenamide: CAP) is a mai or ingredient of hot pepper that has been used as a spicy food additive, preservative, and medicine. In this study, we evaluated the effect of dietary CAP on the selected proto-oncogene(c-jun, c-myc, H-ras, erbB, p53) expressions in various tissues of mice. Male ICR mice were divided into four groups and fed the experimental diets containing CAP at the levels of 0, 5, 20 and 100ppm for four weeks. Steady state RNA levels in various tissues were measured by slot blot hybridization assay. C-jun expression level was enhanced in stomach tissue from mice fed 20ppm CAP and significantly reduced from mice fed 100ppm CAP. The c-jun expression levels were differentially altered in organ-specific manner, Tumor suppressor gene p53 expression level appeared to be slightly increased in the liver from mice fed 20ppm CAP. These results suggested that dietary CAP differentially modulates c-jun and p53 expression in various organs.

• Journal of The Korean Association For Science Education
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• v.31 no.2
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• pp.164-180
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• 2011

In this study, pre-service elementary teachers (n=68) participated in an inquiry of exploring children's science ideas as group work. After conducting interviews with children, the pre-service teachers analyzed their science ideas on specific concept and propose a teaching plan based on their findings. This paper aimed to find the positive learning experiences of the pre-service teachers by looking into their inquiry process. Questionnaire, researcher's journal, classroom videos and final reports were collected and analyzed for this multiple case study. Four representative groups were chosen and interviewed after submitting their final reports for in-depth understanding of their inquiry process. The positive learning experiences found in the process of their inquiry into children's science ideas were as follows: (1) exploring children's ideas have brought the opportunity for enhancing pre-service teachers' science content knowledge. (2) the pre-service teachers developed their ability in creating questions that probe into children's understanding. (3) the pre-service teachers recognized that children have various incomplete and unstable science ideas. (4) the pre-service teachers could suggest teaching strategy based on their findings.