• Biomolecules & Therapeutics
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• 제25권1호
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• pp.69-79
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• 2017

Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.

• 한국유기농업학회지
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• 제28권1호
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• pp.31-57
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• 2020

Korea-US FTA amendment became effective January 1, 2019 through several trade negotiations between the two countries. These amendments did not include changes in the agricultural sector. However, given the policy direction of the Trump administration, it is difficult to be certain that the existing Korea-US FTA on the agricultural sector will remain unchanged. This study examines the potential impact of changes in the US beef import tariff rates under the Korea-US FTA, which is progressively eliminated until 2026 using a dynamic partial equilibrium model. The modelling system is simulated with 100% decreases of tariff rates over 2020~2026 period and then compared to the baseline which is developed based on the current Korea-US FTA tariff rates. According to the scenario analyses results, 100% decreases of US beef tariff rate lowered Korean beef cattle production value up to 4.23%. Looking at this change in terms of absolute value rather than percentage, the total production value over 2020~2026 is expected to decrease by 815 billion won compared to Baseline. This reduction in production value in dynamic analysis is 67 billion won higher than the comparative static analysis.

• 전기전자학회논문지
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• 제23권2호
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• pp.552-556
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• 2019

본 논문에서는 전류 제어 회로를 이용하여 load Transient response 특성을 향상시킨 capless LDO(low drop-out) 레귤레이터를 제안하였다. LDO 레귤레이터 내부의 오차증폭기와 패스 트랜지스터 사이에 전류 조절 회로를 두어 전압 라인에 들어오는 전류특성을 개선시켜 기존의 LDO 레귤레이터보다 향상된 transient 응답특성을 갖는다. 제안된 회로는 cadence의 virtuoso, spectre 시뮬레이터를 이용하여 0.18 um 공정에서 특성을 분석하였다. 실험 결과에 따르면, 제안된 회로 구성을 이용한 LDO의 load transient response는 기존 LDO과 비교하여 부하 전류가 rising time인 경우 1.954 us에서 1.378 us, falling time인 경우 19.48 us에서 13.33 us으로 약 29%, 28% 개선된 응답속도를 가진다.

• Korean Journal of Radiology
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• 제22권4호
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• pp.596-603
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• 2021

Objective: To evaluate the feasibility and diagnostic performance of ultrasound (US)-guided fine-needle aspiration cytology and core-needle biopsy (US-FNAC/CNB) for the diagnosis of laryngo-hypopharyngeal masses. Materials and Methods: This was a single-center prospective case series. From January 2018 to June 2019, we initially enrolled 40 patients with highly suspicious laryngo-hypopharyngeal masses on laryngoscopic examinations. Of these, 28 patients with the mass involving or abutting the pre-epiglottic, paraglottic, pyriform sinus, and/or subglottic regions were finally included. These patients underwent US examinations with/without subsequent US-FNAC/CNB under local anesthesia for evaluation of the laryngo-hypopharyngeal mass. Results: Of the 28 patients who underwent US examinations, a laryngo-hypopharyngeal mass was identified in 26 patients (92.9%). US-FNAC/CNB was performed successfully in 25 of these patients (96.2%), while the procedure failed to target the mass in 1 patient (3.8%). The performance of US caused minor subclinical hematoma in 2 patients (7.7%), but no major complications occurred. US-FNAC/CNB yielded conclusive results in 24 (96.0%) out of the 25 patients with a successful procedure, including 23 patients with squamous cell carcinoma (SCC) and 1 patient with a benign mass. In one patient with atypical cells in US-FNAC, additional direct laryngoscopic biopsy (DLB) was required to confirm SCC. Among the 26 patients who received US-FNAC/CNB, the time from first visit to pathological diagnosis was 7.8 days. For 24 patients finally diagnosed with SCC, the time from first visit to the initiation of treatment was 25.2 days. The mean costs associated with US-FNAC/CNB was $272 under the Korean National Health Insurance Service System. Conclusion: US-FNAC/CNB for a laryngo-hypopharyngeal mass is technically feasible in selected patients, providing good diagnostic performance. This technique could be used as a first-line diagnostic modality by adopting appropriate indications to avoid general anesthesia and DLB-related complications.

• 대한한의학방제학회지
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• 제28권1호
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• pp.41-51
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• 2020

Objectives : US extract is a mixture of each extract of Ulmi cortex and Smilacis rhizoma. In this study, we investigated the antioxidant, anti-inflammatory, antibacterial, and ovoprotective effects of US extract in in vitro model to identify potential candidates for improving female reproductive function. Methods : The antioxidant activity of US extract was measured using 1,1-diphenyl- 2-picrylhydrazyl free radical and superoxide anion radical scavenging assays. The anti-inflammatory effect of US extract on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were determined with a nitric oxide (NO) assay, enzyme linked immunosorbent assays, and western blots analysis. The antibacterial activity of US extract against vaginitis infection microorganisms were determined with disc diffusion and minimum inhibitory concentration assays. The ovoprotective effect of US extract on 4-vinylcyclohexene diepoxide (VCD)-induced ovotoxicity in CHO-K1 cells were evaluated with a cell viability assay. Result : US extract showed good antioxidant capacity and inhibited LPS-induced NO production as well as iNOS and COX-2 expression and secretion of pro-inflammatory cytokine IL-6 without affecting the cell viability. It showed significant clear zones for Staphylococcus aureus and Candida albicans but did not indicate the clear zones for Escherichia coli and Enterococcus faecium. VCD-induced ovotoxicity in CHO-K1 cells was significantly reduced by US extract pre-treatment. Conclusions : These results demonstrate that US extract has antioxidant activity, anti-inflammatory effects on the LPS-stimulated macrophages, antibacterial activity against vaginitis infection microorganisms, and protective effects on the ovarian cells against VCD-induced ovotoxicity. These findings suggest that the US extract can be used as new prescriptions, supplements, functional foods, and cosmetics for improving female reproductive function.

• Korean Journal of Mathematics
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• 제28권1호
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• pp.89-104
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• 2020

In this paper, we connect (α, β) union soft sets and their ideal related properties with KU-algebras. In particular, we will study (α, β)-union soft sets, (α, β)-union soft ideals, (α, β)-union soft commutative ideals and ideal relations in KU-algebras. Finally, a characterization of ideals in KU-algebras in terms of (α, β)-union soft sets have been provided.

• 수산해양교육연구
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• 제28권2호
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• pp.489-501
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• 2016

The purpose of this research is to analyze the narratives of elementary school history textbooks of Korea and US. The research problems are as follows. Firstly, what are the form and content of narratives of Korea's elementary school history textbook of Korea and US. Secondly, what are the characteristics of narratives of American elementary school history textbook of Korea and US. The content analysis method was utilized for analyzing narratives of textbooks. Research results are summarized as follows. Firstly, the features of Korea's elementary school history textbook are described. Secondly, the features of American elementary school history textbook are described. Thirdly, the common features and differences between both countries' textbook narratives are analyzed. Lastly, the implications for diversifying the narratives of Korea's elementary school history textbook are recommended.

• 지역사회간호학회지
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• 제28권2호
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• pp.173-181
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• 2017

Purpose: Early sexual intercourse is associated with poor health outcomes in adolescents. It is known that sexual intercourse coincides with other health risk behaviors such as smoking, drinking, and using drugs. The purpose of this study is to identify the relationships between sexual intercourse and health risk behaviors among Korean and US adolescents using nationally representative data. Methods: Data were collected from the 2011 Korea Youth Risk Behavior Web-based Survey (29,676 students) and 2011 Youth Risk Behavior Surveillance System (10,135 high school students). Logistic regression analysis was performed. Results: In Korea, students who had sexual intercourse accounted for 7.0% in total. Among these, 9.7% were male and 4.2% were female students. In the US, a total of 51.3% students had sexual intercourse, and the proportion of the US male (49.3%) and female (53.4%) students who had sexual intercourse was similar. Korean and US students who experienced sexual intercourse were more likely to smoke, drink alcohol, and use drugs. Conclusion: Since the results of this study show the relationships between sexual intercourse and health risk behaviors, it is necessary to develop comprehensive sex education programs with effective strategies to reduce health risk behaviors in adolescents.

• ETRI Journal
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• 제28권4호
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• pp.541-544
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• 2006

From its foundation until 2004, ETRI has registered over 1,000 US patents. This letter analyzes the characteristics of these patents and addresses the explanatory factors affecting their citation counts. For explanatory variables, research team related variables, invention specific variables, and geographical domain related variables are suggested. Zero-altered count data models are used to test the impact of independent variables. A key finding is that technological cumulativeness, the scale of invention, outputs in the electronic field, and the degree of dependence on the US technology domain positively affect the citation counts of ETRI-invented US patents. The magnitude of international presence appears to negatively affect the citation counts of ETRI-invented US patents.

• Korean Journal of Radiology
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• 제2권4호
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• pp.197-203
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• 2001

Objective: To compare the clinical utility of contrast-enhanced color Doppler US in the differentiation of retinal detachment (RD) from vitreous membrane (VM) with that of various conventional US modalities, and to analyze the enhancement patterns in cases showing an enhancement effect. Materials and Methods: In 32 eyes examined over a recent two-year period, RD (n=14) and VM (n=18) were confirmed by surgery (n=28) or clinical follow-up (n=4). In all cases, gray-scale, color Doppler, and power Doppler US were performed prior to contrast injection, and after the intravenous injection of Levovist (Schering, Berlin) by hand for 30 seconds at a dose of 2.5 g and a concentration of 300 mg/mL via an antecubital vein, contrast-enhanced color Doppler US was performed. At Doppler US, the diagnostic criterion for RD and VM was whether or not color signals were visualized in membranous structures. Results: Diagnostic accuracy was 78% at gray-scale US, 81% at color Doppler US, 59% at power Doppler US, and 97% at contrast-enhanced color Doppler US. The sensitivity of color Doppler US to color signals in RD increased from 57% to 93% after contrast enhancement. The enhancement patterns observed were signal accentuation (n=3), signal extension (n=2), signal addition (n=3), and new signal visualization (n=5). Conclusion: Contrast-enhanced color Doppler US was the most accurate US modality for differentiating RD from VM, showing a significantly increased signal detection rate in RD.