• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.349-354
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• 2006

The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

• 한국실내디자인학회논문집
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• 제18권6호
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• pp.202-210
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• 2009

This research was undertaken to prove the relationship between street mall activation and architectural plan design. The research methodology was established based on the analysis of data of two existing street malls in Korea (Western Dome & LaFesta) and theoretical studies of outdoor space design. The findings from this study are the following: First, building blocks with segments in every 50m or so are ideal for detailed communication between visitors and building contents. Second, the ratio of width of main corridor and building height should be less than 1 to provide intimate feel and keep visitors' attention concentrated in the facility. Third, store unit should have more storefronts to be exposed more to passers-by and lead more pedestrian traffic. Fourth, shape of store unit would rather be wide and shallow, instead of narrow and deep, to have more exposure to the central corridor. Fifth, the building block of the busiest(most expensive) area that is usually at the main entrance area of street mall should be flexible to fit more smaller units to maximize the profitability. Sixth, the main entrance of store should face the main pedestrian corridor to induce the influx of visitors. Lastly seventh, anchor tenant that has strong name recognition is usually located on basement or higher level to induce pedestrian traffic into the mall, key tenants that are strong and familiar brand names should be located at the corner of building block with spacing to attract visitors, provide even distribution of traffic, and support wayfinding, and local tenant should be located at small units along the central corridor or remainder spaces occurred from building core layout.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.920-925
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• 2010

본 논문은 유무선 네트워크와 댁내 가전기기로 구성된 홈 네트워크 시스템은 각종 외부 위협요소로부터의 사이버 공격 대상이 될 수 있을 뿐만 아니라 해킹, 악성코드, 웜 바이러스, DoS공격, 통신망 도청 등의 보안취약성을 가지고 있다. 이로 인해 사생활 침해, 개인정보의 노출, 개인정보의 도용 등 많은 문제가 발생한다. 따라서 홈 네트워크상에서 해당 사용자의 자산 및 개인정보를 보호할 수 있는 보안 프로토콜의 필요성은 점차 증대되어가고 있다. 따라서 본 논문에서는 공개키 인증서를 이용하여 사용자를 인증하고 인증된 정보를 기반으로 해당 기기에 대한 권한을 차등 부여함으로서 허가 받지 않은 사용자로부터의 댁내 자산 및 개인 정보를 보호할 수 있는 사용자 인증과 접근제어 기술을 이용한 홈 네트워크 보안 프로토콜을 설계하고 제안한다.

• 한국재료학회지
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• 제27권12호
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• pp.658-663
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• 2017

Urchin-structured zinc oxide(ZnO) nanorod(NR) gas sensors were successfully demonstrated on a polyimide(PI) substrate, using single wall carbon nanotubes(SWCNTs) as the electrode. The ZnO NRs were grown with ZnO shells arranged at regular intervals to form a network structure with maximized surface area. The high surface area and numerous junctions of the NR network structure was the key to excellent gas sensing performance. Moreover, the SWCNTs formed a junction barrier with the ZnO which further improved sensor characteristics. The fabricated urchin-structured ZnO NR gas sensors exhibited superior performance upon $NO_2$ exposure with a stable response of 110, fast rise and decay times of 38 and 24 sec, respectively. Comparative analyses revealed that the high performance of the sensors was due to a combination of high surface area, numerous active junction points, and the use of the SWCNTs electrode. Furthermore, the urchin-structured ZnO NR gas sensors showed sustainable mechanical stability. Although degradation of the devices progressed during repeated flexibility tests, the sensors were still operational even after 10000 cycles of a bending test with a radius of curvature of 5 mm.

• 대한한방부인과학회지
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• 제18권1호
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• pp.15-28
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• 2005

To address the ability of Kung-Kyung-Ilho-Jeon(KK) to induce cell death, we investigated the effect of KK on cell viability. Forty-eight hours later, loss of viability occurred following KK exposure in a dose-dependent manner. The treatment of KK, a commonly used herb formulation in Korea and China, caused a decrease in cell viability. KK also resulted in apoptotic morphology a brightly blue-fluorescent condensed nuclei by Hoechst 33258-staining, and reduction of cell volume. Our results show that KK induces caspase-3 and -9 activation in a time-dependent manner. In addtion, the translocation of cytochrome c release into cytoplasm has been observed under the presence of $5mg/m{\ell}$ KK. The subsequent loss of mitochondria membrane potential is collapsed by the addition of KK. Our immunoblotting data show that PARP, a well known caspase-3 and -6 substrate, is cleaved by KK. We show that a pro-apoptotic protein, Bax is increased in the presence of KK but that the amount of Bcl-2 is not changed. We suggest that Bax, a critical protein which can regulate channel of mitochondria to release cytochrome c, is a key protein in KK-induced apoptosis of Hela human cervical carcinoma cells

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.317.2-317.2
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• 2013

Ultrathin oxide encapsulated metal-oxide hybrid nanocatalysts have been fabricated by a soft chemical and facile route. First, SiO2 nanoparticles of 25~30 nm size have been synthesized by modified Stobber's method followed by amine functionalization. Metal nanoparticles (Ru, Rh, Pt) capped with polymer/citrate have been deposited on functionalized SiO2 and finally an ultrathin layer of TiO2 coated on surface which prevents sintering and provides high thermal stability while maximizing the metal-oxide interface for higher catalytic activity. TEM studies confirmed that 2.5 nm sized metal nanoparticles are well dispersed and distributed throughout the surface of 25 nm SiO2 nanoparticles with a 3-4 nm TiO2 ultrathin layer. The metal nanoparticles are still well exposed to outer surface, being enabled for surface characterization and catalytic activity. Even after calcination at $600^{\circ}C$, the structure and morphology of hybrid nanocatalysts remain intact confirm the high thermal stability. XPS spectra of hybrid nanocatalyst suggest the metallic states as well as their corresponding oxide states. The catalytic activity has been evaluated for high temperature CO oxidation reaction as well as photocatalytic H2 generation under solar simulation. The design of hybrid structure, high thermal stability, and better exposure of metal active sites are the key parameters for the high catalytic activity. The maximization of metal-TiO2 interface interaction has the great role in photocatalytic H2 production.

• Nutrition Research and Practice
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• 제2권2호
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• pp.114-120
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• 2008

A diet habit, which is developed in childhood, lasts for a life time. In this sense, nutrition education and early exposure to healthy menus in childhood is important. Children these days have easy access to the internet. Thus, a web-based nutrition education program for children is an effective tool for nutrition education of children. This site provides the material of the nutrition education for children with characters which are personified nutrients. The 151 menus are stored in the site together with video script of the cooking process. The menus are classified by the criteria based on age, menu type and the ethnic origin of the menu. The site provides a search function. There are three kinds of search conditions which are key words, menu type and "between" expression of nutrients such as calorie and other nutrients. The site is developed with the operating system Windows 2003 Server, the web server ZEUS 5, development language JSP, and database management system Oracle 10 g.

• Journal of Korean Medical Science
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• 제33권50호
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• pp.318.1-318.10
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• 2018

Background: In this prospective cohort study, we investigated the association between fatty acid ethyl esters (FAEEs) in meconium as biomarkers of prenatal ethanol exposure and growth deficits, as birth outcomes, that constitute several of the key cardinal features of fetal alcohol syndrome. Methods: A total of 157 meconium samples were collected from enrolled infants within 24 hours of birth, and nine FAEEs were quantified using liquid chromatography/tandem mass spectrometry. The relationships between cumulative concentrations of nine species of FAEEs in meconium and birth parameters of growth (age-sex-specific centiles of head circumference [HC], weight, and length) and respective and combined birth outcomes of growth deficits (HC ${\leq}10th$ centile, weight ${\leq}10th$ centile, and length ${\leq}10th$ centile) were determined. Results: Multivariate logistic regression analysis demonstrated that higher cumulative concentrations of meconium FAEEs correlated with elevated risks for HC and length, both, 10th percentile or less (adjusted odds ratio [aOR], 2.94; 95% confidence interval [CI], 1.12-7.74; P = 0.029) and HC and weight and length, all of them, 10th percentile or less (aOR, 3.27; 95% CI, 1.12-9.59; P = 0.031). Conclusion: The elevated cumulative FAEEs in meconium were associated with combined growth deficits at birth, specifically HC and length, both, 10th percentile or less, which might be correlated with detrimental alcohol effects on fetal brain and bone development, suggesting a plausible alcohol-specific pattern of intrauterine growth restriction.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1263-1268
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• 2018

Three different ice core samples from Antarctica were analyzed to identify activity concentrations of radioactive isotopes. Tracking migration of radioactive isotopes to Antarctica can provide a key clue to understand global environmental changes caused by radiation exposures because the Antarctic ice cores can preserve unique characteristics of various environmental conditions. We are particularly interested in the $^{137}Cs$ nucleus, because it is closely related to radiation exposure from nuclear power plant accidents and nuclear bomb tests. With its half life of $30.17{\pm}0.03$ years, $^{137}Cs$ can also be used to assess the age of sedimentation occurring after around the year 1945. We selected three ice core samples, called Tarn8, Styx27, and H25, from different time periods; the Tarn8 sample is known to be from earlier than ~ 1000 AD, the Styx27 sample is approximately from the year 1945, and the H25 sample is from the year 2012. Radioactive isotope measurements of the ice core samples were performed using a 100% HPGe detector at Cheongpyeong Underground Radiation Laboratory (CURL). We measured the activity of $^{137}Cs$ in the H25 sample to be $0.98{\pm}0.82mBq/kg$. Although the activity has a large uncertainty mainly due to the limited sample quantity, the $^{137}Cs$ isotopes in the Antarctic ice core were measured for the first time in Korea.

• Parasites, Hosts and Diseases
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• 제57권3호
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• pp.225-232
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• 2019

Innate lymphoid cells (ILCs) are key players during an immune response at the mucosal surfaces, such as lung, skin, and gastrointestinal tract. Giardia lamblia is an extracellular protozoan pathogen that inhabits the human small intestine. In this study, ILCs prepared from the lamina propria of mouse small intestine were incubated with G. lamblia trophozoites. Transcriptional changes in G. lamblia-exposed ILCs resulted in identification of activation of several immune pathways. Secretion of interleukin (IL)-17A, IL-17F, $IL-1{\beta}$, and interferon-${\gamma}$ was increased, whereas levels of IL-13, IL-5, and IL-22, was maintained or reduced upon exposure to G. lamblia. Goup 3 ILC (ILC3) was found to be dominant amongst the ILCs, and increased significantly upon co-cultivation with G. lamblia trophozoites. Oral inoculation of G. lamblia trophozoites into mice resulted in their presence in the small intestine, of which, the highest number of parasites was detected at the 5 days-post infection. Increased ILC3 was observed amongst the ILC population at the 5 days-post infection. These findings indicate that ILC3 from the lamina propria secretes IL-17 in response to G. lamblia, leading to the intestinal pathology observed in giardiasis.