• Korean Journal of Microbiology
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• v.49 no.2
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• pp.211-214
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• 2013

Bisphenol A (BPA) is a highly hazardous component to human since it is regarded as one of endocrine disruptors. For the analysis and/or removal of BPA, the searching for the specific ligand with a selective affinity to target BPA is required. In order to find the peptide moiety that specifically binds to BPA, the ultrasound-assisted biopanning was carried out with a phage-displayed peptide library expressing constrained heptamer. After six rounds of positive screening against BPA particles followed by the negative screening against the surface of eppendorf tube, the peptide sequence (CysLysSerLeuGluAsnSerTyrCys) with affinity to BPA was screened based on the order of frequency from the screened phage clones. To further verify the specificity of screened peptide sequence, the cross-binding affinity of the phage peptide toward BPA analogues such as Bisphenol S (BPS) and Bisphenol F (BPF) was also assessed, where the selected phage peptide showed a higher affinity to BPA over BPS and BPF.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.37-40
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• 2012

The apidaecins are highly active against Gram-negative bacteria. Here, we show the expression and antibacterial activity of the bumblebee, Bombus ignitus, apidaecin. We PCR-amplified 51 bp of the active domain sequence of the B. ignitus apidaecin gene and expressed the recombinant B. ignitus apidaecin active domain in baculovirus-infected insect cells. The recombinant B. ignitus apidaecin active domain shows bactericidal activity against Gram-negative bacteria, including Pseudomonas tolaasii, a serious pathogen in cultivated mushrooms, but not Gram-positive bacteria. This result suggests that the active domain of the B. ignitus apidaecin is a potential antibacterial agent for the control of bacterial brown blotch diseases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1355-1361
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• 2016

The inter-turn fault (ITF) causes the negative sequence components in the d -q voltage equation due to an increase in the unbalance of three-phase input currents. For this reason, d -q voltage equation become complicate as the voltage equation is classified into positive and negative components. In this study, we propose a simplified d -q equivalent circuit of an interior permanent magnet synchronous motor under ITF state. First, we proposed modeling method for d -q current based on the finite element method simulation results. Then, we developed the simplified d -q equivalent circuit by applying the proposed d -q current modeling.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.13-21
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• 2010

Chicken anemia virus (CAV) has been recognized as an immunosuppressive agent and plays role as an etiological agent of multifactorial diseases in chicken. In this study, we investigated distribution of CAV antibody by ELISA and the virus gene by PCR in poultry farms in Jeongeup, Jeonbuk province. In the test using ELISA kit, 41 (95.3%) of 43 flocks and 88.6% of the individual chickens were positive, respectively. By PCR, 90.9% of the broiler breeders and 75.0% of White-semi breeders were found positive, respectively. All hatchery was negative by PCR. Of the clinical cases from 49 poultry flocks, 87.5% of flocks and 54.7% for each samples were found positive by ELISA, respectively. By PCR test, 21 (42.9%) of 49 flocks were positive. Major clinical signs of the infected flocks were growth retardation, femoral subcutaneous bleeding, depression, limping, and continuing selection. The genetic analysis of separate N genes of CAV showed highly homologous each other. The nucleotide sequence of field isolates had homology ranged from 99.9% to 97.5% with Chinese strains, and 99.9% to 99.6% with Japanese strain. Phylogenetic analysis based on the N gene of CAV isolates showed the closely relation with Chinese strains. The results of this survey could be used as basic data for development of vaccine.

• Communications of the Korean Mathematical Society
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• v.35 no.1
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• pp.137-149
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• 2020

Let γ⁽ⁿ⁾ ≡ {γ_ij} (0 ≤ i+j ≤ 2n, |i-j| ≤ n) be a sequence in the complex number set ℂ and let E (n) be the Embry truncated moment matrices corresponding from γ⁽ⁿ⁾. For an odd number n, it is known that γ⁽ⁿ⁾ has a rank E (n)-atomic representing measure if and only if E(n) ≥ 0 and E(n) admits a flat extension E(n + 1). In this paper we suggest a related problem: if E(n) is positive and nonsingular, does E(n) have a flat extension E(n + 1)? and give a negative answer in the case of E(3). And we obtain some necessary conditions for positive and nonsingular matrix E (3), and also its sufficient conditions.

• Journal of the Korean Mathematical Society
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• v.43 no.3
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• pp.529-538
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• 2006

In this paper we derive the central limit theorem for ${\sum}^n_{i=l}\;a_{ni}{\xi}_{i},\;where\;\{a_{ni},\;1\;{\le}\;i\;{\le}n\}$ is a triangular array of non-negative numbers such that $sup_n{\sum}^n_{i=l}\;a^2_{ni}\;<\;{\infty},\;max_{1{\le}i{\le}n\;a_{ni}{\to}\;0\;as\;n{\to}{\infty}\;and\;{\xi}'_{i}s$ are a linearly positive quadrant dependent sequence. We also apply this result to consider a central limit theorem for a partial sum of a generalized linear process of the form $X_n\;=\;{\sum}^{\infty}_{j=-{\infty}}a_{k+j}{\xi}_{j}$.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.596-603
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• 2002

In this paper a new harmonic reduction method of three-phase diode rectifiers is proposed to improve input current performance using the zero-sequence harmonics injection technique. The proposed mothed, based on the third-harmonic injection, employs two half-bridge inverters and two single-phase transformers to independently shape the positive and negative dc rail currents of the diode rectifier. The actively shaped zero-sequence harmonic currents are t]ten circulated through the ac side of the rectifier using a zigzag transformer This results in pure sinusoidal input currents in the three-phase diode rectifier. Experimental results on a 1.5kVA prototype are provided to validate the proposed technique.

• Molecules and Cells
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• v.43 no.8
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• pp.694-704
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• 2020

HslUV is a bacterial heat shock protein complex consisting of the AAA+ ATPase component HslU and the protease component HslV. HslV is a threonine (Thr) protease employing the N-terminal Thr residue in the mature protein as the catalytic residue. To date, HslUV from Gram-negative bacteria has been extensively studied. However, the mechanisms of action and activation of HslUV from Gram-positive bacteria, which have an additional N-terminal sequence before the catalytic Thr residue, remain to be revealed. In this study, we determined the crystal structures of HslV from the Gram-positive bacterium Staphylococcus aureus with and without HslU in the crystallization conditions. The structural comparison suggested that a structural transition to the symmetric form of HslV was triggered by ATP-bound HslU. More importantly, the additional N-terminal sequence was cleaved in the presence of HslU and ATP, exposing the Thr9 residue at the N-terminus and activating the ATP-dependent protease activity. Further biochemical studies demonstrated that the exposed N-terminal Thr residue is critical for catalysis with binding to the symmetric HslU hexamer. Since eukaryotic proteasomes have a similar additional N-terminal sequence, our results will improve our understanding of the common molecular mechanisms for the activation of proteasomes.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.147-154
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• 2015

Various constituents in clinical specimens, particularly feces, can inhibit the PCR assay and lead to false-negative results. To ensure that negative results of a diagnostic PCR assay are true, it should be properly monitored by an inhibition control. In this study, a cloning vector harboring a modified target DNA sequence (${\approx}375bp$) was constructed to be used as a competitive internal amplification control (IAC) for a conventional PCR assay that detects ${\approx}550bp$ of the Cryptosporidium oocyst wall protein (COWP) gene sequence in human feces. Modification of the native PCR target was carried out using a new approach comprising inverse PCR and restriction digestion techniques. IAC was included in the assay, with the estimated optimum concentration of 1 fg per reaction, as duplex PCR. When applied on fecal samples spiked with variable oocysts counts, ${\approx}2$ oocysts were theoretically enough for detection. When applied on 25 Cryptosporidium-positive fecal samples of various infection intensities, both targets were clearly detected with minimal competition noticed in 2-3 samples. Importantly, both the analytical and the diagnostic sensitivities of the PCR assay were not altered with integration of IAC into the reactions. When tried on 180 randomly collected fecal samples, 159 were Cryptosporidium-negatives. Although the native target DNA was absent, the IAC amplicon was obviously detected on gel of all the Cryptosporidium-negative samples. These results imply that running of the diagnostic PCR, inspired with the previously developed DNA extraction protocol and the constructed IAC, represents a useful tool for Cryptosporidium detection in human feces.

• BMB Reports
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• v.51 no.1
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• pp.1-2
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• 2018

Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.