• Reproductive and Developmental Biology
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• 제34권2호
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• pp.95-101
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• 2010

Decorin (DCN) is a member of small leucine-rich proteoglycans which are ubiquitous components of the extracellular matrix. It regulates many physiological processes, such as matrix formation, collagen fibrillogenesis, angiogenesis, cancer growth, and cardiovascular diseases. It has been shown that DCN is expressed in the uterus during pregnancy and modulates implantation and decidualization for the establishment and maintenance of pregnancy in mice and humans. Expression of DCN in the uterine endometrium during pregnancy has not been investigated in pigs. Thus, this study investigated expression of DCN in the uterine endometrium during the estrous cycle and pregnancy in pigs. Uterine endometrial tissues were from day (D) 12 and 15 of the estrous cycle and D12, D15, D30, D60, D90, and D114 of pregnancy. Northern blot and real-time RT-PCR analyses showed that expression of DCN mRNA was detected throughout the estrous cycle and pregnancy with the highest levels during mid pregnancy. In situ hybridization analysis showed that DCN mRNA was localized to both luminal and glandular epithelia during the estrous cycle and pregnancy and also to chorionic membrane during mid pregnancy in pigs. To determine whether endometrial expression of DCN was affected by the somatic cell nuclear transfer (SCNT) procedure, DCN mRNA levels in the uterine endometrium from gilts with SCNT embryos on D30 of pregnancy were compared with those from gilts with normal embryos using real-time RT-PCR analysis. The result showed that DCN mRNA levels in the uterine endometrium were not significantly different between gilts with normal embryos and SCNT embryos. These results suggest that DCN may play an important role for endometrial tissue remodeling during mid pregnancy, and DCN expression is not affected by the SCNT procedure at the early stage of pregnancy in pigs.

• 태양에너지
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• 제19권3호
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• pp.23-28
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• 1999

본 논문에서는 난방용 축열보드에 응용하기 위해서 미세캡슐을 함유한 축열블럭의 열성능 특성을 조사하였다. 상변화 물질인 $CH_3COONa{\cdot}3H_2O$를 미세캡슐 형태로 제조하였고 미세캡슐 함유량이 각각 10%, 20%가 되도록 시멘트 몰타르와 혼합하여 축열블럭을 제작하였다. 축열블럭의 축열 및 방열 특성을 분석하기 위하여 유량과 유입 냉각 온도를 변화시켰다. 실험결과를 보면 미세캡슐 함유량이 증가할 수록 블럭에 축열되는 축열량은 증가를 하였고 방열시간도 증가를 하였다. 그리고 방열과정시 유량이 증가하고 유입 냉각온도가 감소함에 따라 방열시간은 감소하였다. 순수블럭(0% 미세캡슐 함유량)은 방열과정시 총괄 열전달 계수는 시간에 따라서 일정하게 유지를 하지만 축열블럭에서는 시간이 지남에 따라 증가를 하였다.

• 한국어류학회지
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• 제20권1호
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• pp.1-6
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• 2008

제브라피쉬 배아로부터 확보한 세포주로부터 외부형태와 세포 크기에 따라 3종류의 동형세포주를 확립하였다. 활발하게 증식하는 안정된 세포주 및 이들로부터 확립된 동형세포주의 세포특성은 변하지 않고 지속적으로 유지되었으며, 안정된 세포주로부터 총 18개의 콜로니를 확보하여 배양한 다음 3종류의 동형세포주를 선별하여 세포 특성을 분석하였다. 대부분의 동형세포주는 약 80% 정도 정상적인 염색체(2N=50)를 가지고 있었으며 FACs 분석과 일치하였다. 배아로부터 확립된 동형세포주에 항체테스트 결과, vimentin에서 양성을 보이는 결과로 볼 때 확립된 세포주는 분화된 섬유세포임이 확인되었다. 이러한 결과는, 확립된 동형세포주를 이용한 유전자조작과 어류복제에의 활용도를 높일 수 있음을 시사한다.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3676-3680
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• 2012

An Epstein-Barr virus (EBV)-based plasmid contains the EBV nuclear antigen 1 (EBNA1) gene and EBV replication origin (oriP) sequence. Since EBNA1 (the only EBV-encoded protein) is combined with oriP, it is replicated simultaneously with chromosomal DNA in human, primate, and canine cells and is faithfully segregated at a stable copy number upon cell division. Consequently, it can be used to stably express gene inserts over a prolonged time in target cells. We have previously shown that the polyamidoamine (PAMAM) dendrimer can be surface-modified with L-arginine. Arginine is present at a high frequency in the transactivator of transcription (Tat) sequences of human immunodeficiency virus (HIV). It presents high membrane permeability and permits effective transfer of DNA inside the cells. In this study, we constructed two kinds of recombinant DNA by inserting the luciferase gene and enhanced green fluorescence protein (eGFP) gene as reporter genes into the pCEP4 plasmid vector. We measured dynamic light scattering (DLS) and zeta potential after preparing PAMAM-based cationic polymer/EBV-based plasmid complexes. We performed transfection of HEK 293 cell lines with the polyplexes, and monitored luciferase activity and green fluorescence protein (GFP) expression. Our results show that PAMAM-based cationic polymer/EBV plasmid complexes provide enhanced and sustained gene expression.

• Journal of Radiation Protection and Research
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• 제28권2호
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• pp.127-135
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• 2003

The primary contributors to the total occupational radiation exposure in operating nuclear power plants are operation and maintenance activities doting refueling outages. The Advanced Power Reactor 1400 (APR1400) includes a number of design improvements and plans to utilize advanced maintenance methods and robotics to minimize the annual collective dose. The major radiation exposure reduction features implemented in APR1400 are a permanent refueling pool seal, quick opening transfer tube blind flange, improved hydrogen peroxide injection at shutdown, improved permanent steam generator work platforms, and more effective temporary shielding. The estimated average annual occupational radiation exposure for APR1400 based on the reference plant experience and an engineering judgment is determined to be in the order of 0.4 man-Sv, which is well within the design goal of 1 man-Sv. The basis of this average annual occupational radiation exposure estimation is an eighteen (18) month fuel cycle with maintenance performed to steam generators and reactor coolant pumps during refueling outage. The outage duration is assumed to be 28 days. The outage work is to be performed on a 24 hour per day basis, seven (7) days a week with overlapping twelve (12) hour work shifts. The occupational radiation exposure for APR1400 is also determined by an alternate method which consists of estimating radiation exposures expected for the major activities during the refueling outage. The major outage activities that cause the majority of the total radiation exposure during refueling outage such as fuel handling, reactor coolant pump maintenance, steam generator inspection and maintenance, reactor vessel head area maintenance, decontamination, and ICI & instrumentation maintenance activities are evaluated at a task level. The calculated value using this method is in close agreement with the value of 0.4 man-Sv, that has been determined based on the experience aid engineering judgement. Therefore, with the As Low As Reasonably Achievable (ALARA) advanced design features incorporated in the design, APR1400 design is to meet its design goal with sufficient margin, that is, more than a factor of two (2), if operated on art eighteen (18) month fuel cycle.

• Food Science and Biotechnology
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• 제16권1호
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• pp.127-132
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• 2007

[ ${\alpha},\;{\alpha}$ ]-Trehalose was efficiently modified by a transgalactosylation reaction of Escherichia coli ${\beta}-galactosidase$ using lactose as a donor to yield two galactosyl trehalose trisaccharides. The reaction products of trehalose by the enzyme were observed by thin layer chromatography (TLC) and high performance anion exchange chromatography (HPAEC) and were purified by BioGel P2 gel permeation chromatography and recycling preparative HPLC. Liquid chromatography-mass spectrometry (LC-MS) and ^{13}C$ nuclear magnetic resonance (NMR) analyses revealed that the structures of the main products were $6^2-{\beta}-D-galactosyl$ trehalose (1) and $4^2-{\beta}-D-galactosyl$ trehalose (2). A reaction of 30%(w/v) trehalose and 15%(w/v) lactose at pH 7.5 and $45^{\circ}C$ resulted in a total yield of approximately 27-30% based on the amount of trehalose used. The galactosyl trehalose products were not hydrolyzed by trehalose. In addition the mixture of transfer products (9:1 ratio of 1 to 2) showed higher thermal stability than glucose, lactose, and maltose, but less than trehalose, against heat treatment over $100^{\circ}C$ at pH 4 and 7. It also exhibited better thermal stability than sucrose at pH 4 alone.

• 한국군사과학기술학회지
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• 제20권6호
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• pp.767-773
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• 2017

Infrared stealth is an important technology for naval ships. This technology helps improve the anti-detection performance and survivability of naval ships. In general, the infrared signature of naval ships are categorized into internal and external heat source. External signature are generated by ship surface heating by solar flux as well as the complicated heat transfer process with the surrounding weather condition. Modern naval ships are equipped with seawater injection nozzles on the outside for nuclear, biological and, chemical, and these nozzles are used to control external signature. Wide nozzle placement intervals and insufficient injection pressure, however, have reduced seawater dispersion area. To address this problem, nozzle installation standards must be established. In this study, an actual-scale experimental system was implemented to provide the evidence for nozzle installation standards in order to reduce the infrared signature of naval ships. In addition, the environmental conditions of the experiment were set up through computational fluid dynamics considering the ocean climate data and naval ship management conditions of South Korea. The dispersion distance was measured using a high-resolution thermography system. The flow rate, pipe pressure, and dispersion distance were analyzed, and the evidence for the installation of seawater injection nozzles and operation performance standards was suggested.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.533-538
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• 2003

It has been shown that ion implantation produces remarkable improvements in surface-sensitive physical and chemical properties as well as other mechanical properties, in polymers. In this study, ion implantation was performed onto polymer, PC(polycarbonate), in order to investigate surface hydrophilic property through contact angle measurement using distilled water. PC was irradiated with N, Ar, Xe ions at the irradiation energy of $20\;{\sim}\;50keV$ and the dose range of $5{\times}10^{15},\;1{\times}10^{16},\;7{\times}10^{16}\;ions/cm^2$. The contact angle of water has been reduced with increasing fluence and ion mass but increased with increasing implanted energy. The changes of chemical and structural property are discussed in view of infrared spectroscopy and FT-IR, XPS, which shows increasing C-O bonding and C-C bonding. The root mean square of surface roughness examined by means of AFM changed smoothly from 0.387nm to 0.207nm and the change of wettability was discussed with respect to elastic and inelastic collisions obtained as results of TRIM simulation. It was found that wettability of the modified PC surface was affected on change of functional group and nuclear stopping or linear energy transfer(LET, energy deposited per unit track length per ion) that causes chain scission by displacing atom from polymer chains, but was not greatly dependant on surface morphology.

• Journal of Korean Medical Science
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• 제33권48호
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• pp.295.1-295.7
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• 2018

Background: Vancomycin-resistant enterococci (VRE) infections have become a major healthcare-associated pathogen problem worldwide. Nosocomial VRE infections could be effectively controlled by screening patients at high risk of harboring VRE and thereby lowering the influx of VRE into healthcare centers. In this study, we evaluated factors associated with VRE colonization in patients transferred to emergency departments, to detect patients at risk for VRE carriage. Methods: This study was conducted in the emergency department of a medical college-affiliated hospital in Korea. Every patient transferred to the emergency department and admitted to the hospital from January to December 2016 was screened for VRE using rectal cultures. In this cross-sectional study, the dependent variable was VRE colonization and the independent variables were demographic and clinical factors of the patients and factors related to the transferring hospital. Patients were divided into two groups, VRE and non-VRE, and previously collected patient data were analyzed. Then we performed logistic regression analyses of characteristics that differed significantly between groups. Results: Out of 650 patients, 106 (16.3%) had positive VRE culture results. Significant variables in the logistic analysis were transfer from geriatric long-term care hospital (adjusted odds ration [aOR]: 8.017; 95% confidence interval [CI]: 1.378-46.651), hospital days (4-7 days; aOR: 7.246; 95% CI: 3.229-16.261), duration of antimicrobial exposure (1-3 days; aOR: 1.976; 95% CI: 1.137-3.436), and age (aOR: 1.025; 95% CI: 1.007-1.043). Conclusion: VRE colonization in patients transferred to the emergency department is associated primarily with factors related to the transferred hospitals rather than demographic and clinical characteristics.

• 한국의학물리학회지:의학물리
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• 제29권4호
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.