• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.575-584
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• 2012

Listeria monocytogenes is an important foodborne pathogen that comprises four genetic lineages: I, II, III, and IV. Of these, lineage II is frequently recovered from foods and environments and responsible for the increasing incidence of human listeriosis. In this study, the phylogenetic structure of lineage II was determined through sequencing analysis of the ascB-dapE internalin cluster. Fifteen sequence types proposed by multilocus sequence typing based on nine housekeeping genes were grouped into three distinct sublineages, IIA, IIB, and IIC. Organization of the ascB-dapE internalin cluster could serve as a molecular marker for these sublineages, with inlGHE, inlGC2DE, and inlC2DE for IIA, IIB, and IIC, respectively. These sublineages displayed specific genetic and phenotypic characteristics. IIA and IIC showed a higher frequency of recombination (${\rho}/{\theta}$). However, recombination events had greater effect (r/m) on IIB, leading to its high nucleotide diversity. Moreover, IIA and IIB harbored a wider range of internalin and stress-response genes, and possessed higher nisin tolerance, whereas IIC contained the largest portion of low-virulent strains owing to premature stop codons in inlA. The results of this study indicate that IIA, IIB, and IIC might occupy different ecological niches, and IIB might have a better adaptation to a broad range of environmental niches.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.152-152
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• 2003

As utilization of radiation in medicine, industry and biochemical research increases, the protection against radiation damage has become an important issue. Natural products such as herbal medicines are beginning to receive attention as modifiers on the radiation response. In the present study, the protective effect of a herb, Menthae Herba, against radiation-induced DNA damage was evaluated using alkaline single-cell gel electrophoresis (SCGE; comet assay) in the mouse peripheral blood Iymphocytes and the micronucleus formation test in the Chinese hamster ovary (CHO) cells. The tail moment, which was a marker of DNA damage in the SCGE, and the frequency of micronuclei was decreased in groups treated with Mentae Herba extract before exposure to 200 cGy of gamma-ray. We also confirmed its activities to scavenge DPPH and hydroxyl radicals. These experiments demonstrated that Menthae Herba was effective at reducing the radiation-induced damage of DNA and scavenging free radicals. It is plausible that scavenging of free radicals by Menthae Herba may have played an important role in providing the protection against the radiation-induced damage to the DNA. These results indicated that Menthae Herba might be a useful radioprotector and that radical scavenging appears to be one of the mechanisms of radiation protection.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.147-153
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• 2012

Precise estimation f a structure's dynamic characteristics is indispensable for ensuring stable dynamic response during life time especially for the structures which can experience resonance such as railway bridges. Especially, concrete track can change the modal properties of the railway bridge, through the contribution of stiffness as well as mass effects, generally only the mass effect is considered in dynamic analysis of the railway bridge. In this paper, static and dynamic behaviors of railway bridge with concrete track were investigated through experimental study. Also, numerical analysis was performed about considering only mass of concrete track and together with stiffness and mass of concrete track. These were compared with experiment value. Numerical analysis value considering together with stiffness and mass of concrete track was similar experiment value. Therefore, when dynamic analysis of railway bridge with concrete track is performed, the contribution of stiffness as well as mass effects for concrete track is considered.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.131-137
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• 2010

UMSN (Ubiquitous Medical Sensor Network) is being used in u-Healthcare system of various medical facilities to identify objects and get information from sensors in real-time. RFID using radio frequency determines objects using Reader, which reads Tags attached to patients. However, there is a security vulnerability wherein Tag send its ID to illegal Reader because Tags always response to Readers request regarding of its Tag ID. In this paper, we propose Tag ID Classification Scheme to reduce Back-end Server traffic that caused by requests to authenticate between Readers and Tags that are attached to medical devices, patients, and sensors; To reduce security threats like eavesdropping and spoofing that sometimes occurred during authentication procedure. The proposed scheme specifies the patient category as a group based on patients Tag ID string. Only allowed Reader can perform authentication procedure with Back-end Server. As a result, we can reduce Back-end Server traffic and security threats.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.4
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• pp.59-68
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• 1997

In analysis of underground structures, the effects of artificial boundary conditions are considered as one of the major reasons for differences from experimental results. These phenomena can be overcome by using the boundary elements which satisfy the multi-layered half space conditions. The fundamental solutions of multi-layered half-space for boundary element method is formulated satisfying the transmission and reflection of waves at each layer interface and radiation conditions at bottom layer. The governing equations can be obtained from the displacements at each layer which are expressed in terms of harmonic functions. All types of waves can be included using the complete response from semi-infinite integrals with respect to horizontal wavenumbers using expansion of Fourier series and Hankel transformation. Two dimensional Green's functions are derived from cylindrical Navier equations and potentials performing infinite integration in y-direction. In this case, it is effective to transform into two dimensional problem using semi-analytical integration and sinusoidal Bessel function. Some verifications are given to show the accuracy and efficiency of the developed method, and numerical examples to demonstrate the dynamic behavior of underground with various properties.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.425-435
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• 2016

This paper describes a spread-spectrum clock generation method by utilizing a ${\Delta}{\Sigma}$ digital PLL (DPLL) which is solely based on binary phase detection and does not require a linear time-to-digital converter (TDC) or other linear digital-to-time converter (DTC) circuitry. A 1-bit high-order ${\Delta}{\Sigma}$ modulator and a hybrid finite-impulse response (FIR) filter are employed to mitigate the phase-folding problem caused by the nonlinearity of the bang-bang phase detector (BBPD). The ${\Delta}{\Sigma}$ DPLL employs a two-point modulation technique to further enhance linearity at the turning point of a triangular modulation profile. We also show that the two-point modulation is useful for the BBPLL to improve the spread-spectrum performance by suppressing the frequency deviation at the input of the BBPD, thus reducing the peak phase deviation. Based on the proposed architecture, a 3.2 GHz spread-spectrum clock generator (SSCG) is implemented in 65 nm CMOS. Experimental results show that the proposed SSCG achieves peak power reductions of 18.5 dB and 11 dB with 10 kHz and 100 kHz resolution bandwidths respectively, consuming 6.34 mW from a 1 V supply.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.4
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• pp.67-76
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• 2015

The purpose of this study is to set a direction for the development of men's underwear after analyzing current applications for patent regarding men's special-purpose underwear. In terms of a research method, the disclosed patents and utility models were investigated using the patent information database provided by Korea Institute of Patent Information (KIPRIS, http://www.kipris.or.kr). For this, the patents applied from 1990 to October 2015 were targeted. The keywords used for patent search were 'men's underwear' and 'men's special-purpose underwear.' When searched by the keywords above, a total of 1,089 cases were found. Except for expired or cancelled ones, 243 cases were investigated. Then, annual application trends, current registrations on literature records, classification of utility model right holders and contents by topic were analyzed. In terms of data analysis, frequency analysis, crosstabulation analysis and multiple response analysis were conducted, using SPSS 18.0. The results found the followings: In terms of annual application trends, the number of applications for patent started to gradually increase since 2007. Since 2011, it has rapidly increased. In terms of the number of patent registrations, literature registration was far higher than utility model registration. In terms of application rights, 'individually registered (58.8%)' was higher than 'registered by the organization (41.2%).' Among 243 cases, 'underwear (58%)' was the highest, followed by 'men's underwear-related items (29.2%)' and 'thermals (8.2%).' According to analysis on the details of the patent applied for men's underwear, 'penis-scrotum separation' was most focused, followed by 'disposable product' 'airy features,' 'scrotum protection' and 'structure of underwear.'

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.191-198
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• 2011

In this paper, a method to approximate a multi-layer Green's function is proposed based on a FDTD scheme and a rational function approximation. For a given horizontal propagation wavenumber, time domain response is calculated and then Fourier transformed to the spectral domain Green's function. Using the rational function approximation, the pole and residue of the Green's function can be estimated, which are crucial for a calculation of a path loss. The proposed method can provide a wideband Green's function, while the conventional normal mode method can be applied to a single frequency problem. To validate the proposed method, We consider two problems, one of which has a analytical solution. The other is about multi-layer case, for which the proposed method is compared with the known normal mode solution, Kraken.

• International Journal of Oral Biology
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• v.45 no.1
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• pp.1-7
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• 2020

Oral lichen planus (OLP) is a chronic inflammatory disease observed in approximately 0.5-2.2% of the population, and it is recognized as a premalignant lesion that can progress into oral squamous cell carcinoma (OSCC). The rate of malignant transformation is approximately 1.09-2.3%, and the risk factors for malignant transformation are age, female, erosive type, and tongue site location. Malignant transformation of OLP is likely related to the low frequency of apoptotic phenomena. Therefore, apoptosis-related genetic factors, like p53, BCL-2, and BAX are reviewed. Increased p53 expression and altered expression of BCL-2 and BAX were observed in OLP patients, and the malignant transformation rate in these patients was relatively higher. The involvement of microRNA (miRNA) in the malignant transformation of OLP is also reviewed. Because autophagy is involved in cell survival and death through the regulation of various cellular processes, autophagy-related genetic factors may function as factors for malignant transformation. In OLP, decreased levels of ATG9B mRNA and a higher expression of IGF1 were observed, suggesting a reduction in cell death and autophagic response. Activated IGF1-PI3K/AKT/mTor cascade may play an important role in a signaling pathway related to the malignant transformation of OLP to OSCC. Recent research has shown that miRNAs, such as miR-199 and miR-122, activate the cascade, increasing the prosurvival and proproliferative signals.

• Tuberculosis and Respiratory Diseases
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• v.62 no.2
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• pp.134-139
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• 2007

Gefitinib is a novel drug used to treat advanced non-small cell lung cancer. However, drug-related interstitial pneumonia is a major life-threatening side effect, which has a worldwide prevalence of 0.3-0.4%. In Japan, the prevalence is high as 3-4% but the actual frequency in Korea has not been officially assessed. We report two cases of gefitinib-induced interstitial lung disease during the treatment of non-small cell lung cancer. High-resolution computerized tomography (HRCT) of one case showed nonspecific ground glass opacity and the chest x-ray of another case showed diffuse bilateral ground glass opacity. The former patient showed a rapid good response to corticosteroid treatment whereas the latter died despite receiving aggressive treatment with high dose corticosteroid and empirical antibiotics.