• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1382-1387
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• 2004

From the viewpoint of a macro state, there is no thermal boundary resistance (TBR) at an interface if both surfaces at an interface are perfectly contacted. However, recent molecular dynamics (MD) studies reported that there still exists the TDR at the interface in an ideal epitaxial superlttice. Our previous studies suggested the model to predict the TBR not only quantitatively also qualitatively in superlattices. The suggested model was based on the classical theory of a wave reflection, and provided highly satisfactory results for an engineering purpose. However, it was not the complete model because our previous model was derived by considering only the effects from a mass ratio and a potential ratio of two species. The interaction of two species presented by the Lennard-Jones (L-J) potential is governed by the mutual ratio of the masses, the potential well depths, and the diameters. In this study, we performed the preliminary simulations to investigate the effect resulting from the diameter ratio of two species for the completion of our model and confirmed that it was also a ruling factor to the TBR at an interface in superlattices.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.89-94
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• 2013

This paper presents a simple but valid design factor calculation method of grid-connected photovoltaic system using normalized yield model. The proposed calculation method can be represented as a quantitative value about five design factors from irradiance to system output power. The validity of this method is identified by analyzing design factor with three years monitored data. These results will indicate that it is useful to determine the optimal design and selection of grid-connected photovoltaic system to meet different user purposes and enhance long-term reliability and stability of grid-connected photovoltaic system.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.394-404
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• 2003

Certain polycyclic aromatic hydrocarbons (PAHs) have been reported to induce cytochrome P450 (CYP) 1A1 and 1A2. In the present study, the effects of six well-known PAHs, such as benzo[a]pyrene, benz[a]anthracene, dibenz[a,h]anthracene, chrysene, benzo[k]fluorancene and benzo[b]fluorancene, on the activities of hepatic and pulmonary CYP enzymes were investigated in male ICR mice. When mice were treated intraperitoneally with 3, 10 and 30 mg/kg of individual PAHs for 3 consecutive days, the activities of ethoxyresorufin- and methoxyresorufin-Ο-dealkylases were significantly and differentially induced in both liver and lung. Moreover, other CYP isozyme-associated monooxygenase activities were also induced significantly in liver and lung with characteristic induction profiles. Our present results suggest that individual PAHs might have inductive effects on CYP isozymes, and that the characteristic inductive effects of individual PAHs on certain CYP isozymes would be developed as a marker for determining exposure to certain PAHs.

• ETRI Journal
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• v.35 no.4
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• pp.571-577
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• 2013

The fabrication of a thin-film transistor backplane and a liquid-crystal display using printing processes can eliminate the need for photolithography and offers the potential to reduce the manufacturing costs. In this study, we prepare contact via structures through a poly(methyl methacrylate) polymer insulator layer using inkjet printing. When droplets of silver ink composed of a polymer solvent are placed onto the polymer insulator and annealed at high temperatures, the silver ink penetrates the interior of the polymer and generates conducting paths between the top and bottom metal lines through the partial dissolution and swelling of the polymer. The electrical property of various contact via-hole interconnections is investigated using a semiconductor characterization system.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2574-2576
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• 2009

In this work, we describe a new sensor that specifically responds to biothiols, i.e., glutathione (GSH), in solution. An electrochemical transducing strategy was utilized and cyclic voltammetry (CV) was employed to monitor the presence of GSH in real time. Our approach harnessed self-assembled monolayers (SAMs) on gold consisting of an alkanethiolate which was terminated by electroactive quininoid moiety. Prior to thiol molecule treatment, the characterisitc reversible redox peaks of the electroactive quininoid group was observed, while the reduction peak was dramatically shifted upon a treatment of GSH. This sensor showed the capability to detect the GSH in solution in the range of 1 mM $\sim$ 100 aM. We believe that this strategy will provide an important tool for accurate, sensitive, rapid, and low-cost determination of GSH.

• Korean Journal of Bronchoesophagology
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• v.14 no.2
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• pp.57-63
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• 2008

Hypopharyngeal perforation secondary to tracheal intubation is rare, but may result in severe airway complications that include retropharyngeal abscess, pneumothorax, pneumonia, mediastinitis and death. The most common site of hypopharyngeal perforation is the pyriform sinus and the region of the cricopharyngeus muscle. We report a 62-year old man with intubation-induced hypopharyngeal injury presenting as deep neck infection. The patient presented with dyspnea and pain on the neck. Neck CT scan identified fluid and air collection on the neck from the hyoid bone to the thoracic inlet level. Despite of delayed diagnosis, we successfully operated him by using strap muscle myofascial transposition flap. The patient was followed up for 3 months without any complications.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.984-989
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• 2006

1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has been characterized to have an anti-inflammatory activity through the inhibition of the production of nitric oxide and tumor necrosis $factor-{\alpha}$. In the present studies, the phase 1 metabolism of FPP-3 was investigated in rat liver microsomes and cytosols. When FPP-3 was incubated with rat liver microsomes and cytosols in the presence of NADPH. 2 major peaks were detected on a liquid chromatography/electrospray ionization-mass spectrometry. Two metabolites (i.e., M1 and M2) were characterized as reduced forms on propenone: M1 (1-furan-2-yl-3-pyridin-2-yl-propan-1-one) was the initial metabolite and M2 (1-furan-2-yl-3-pyridin-2-yl-propan-1-ol) was a secondary alcohol believed to be formed from M1.

• Communications of Mathematical Education
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• v.20 no.4 s.28
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• pp.503-521
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• 2006

'Calculus for Life Science' is one of the calculus courses for students majoring life science in Seoul National University. Contrary to the other calculus courses for students in natural sciences and engineerings, in 'Calculus for life Science' we have primarily chosen computer-based curriculum that is useful to life science and so we have tried to fulfill the requirements of the students majoring life science. Like this, we are of the opinion that there are diverse requirements in life science as well as other majors in basic mathematical education of the university. Upon this view, in this research, we consider the present conditions, the points at issue and study improvements of them. In section II and III, we introduce briefly the present 'Calculus for Life Science' focused on the curriculum. In section IV, according to the course evaluations and questionnaire, we make an analysis of the present condition and the points at issue of 'Calculus for Life Science'. In section V and VI, we present the improvements of the curriculum and the several education environments.

• Molecules and Cells
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• v.40 no.7
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• pp.485-494
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• 2017

Oleanolic acid (OA) has neurotrophic effects on neurons, although its use as a neurological drug requires further research. In the present study, we investigated the effects of OA and OA derivatives on the neuronal differentiation of rat hippocampal neural progenitor cells. In addition, we investigated whether the class II histone deacetylase (HDAC) 5 mediates the gene expression induced by OA. We found that OA and OA derivatives induced the formation of neurite spines and the expression of synapse-related molecules. OA and OA derivatives stimulated HDAC5 phosphorylation, and concurrently the nuclear export of HDCA5 and the expression of HDAC5 target genes, indicating that OA and OA derivatives induce neural differentiation and synapse formation via a pathway that involves HDAC5 phosphorylation.

• Journal of Korean Biological Nursing Science
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• v.20 no.1
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• pp.30-37
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• 2018

Purpose: The purpose of this study was to examine the relationship between sleep quality and stress among nursing students. Methods: A cross-sectional study was conducted with 94 nursing students from a University in Seoul. Participants completed questionnaires and the data were analyzed using t-test, ANOVA, and Pearson correlation coefficients. Results: The mean score of sleep quality was $6.93{\pm}2.66$ among nursing students and 81.9% had a sleep problem. The mean score of stress was $18.61{\pm}4.84$. Sleep quality was significantly different by clinical practice days per week, subjective physical health status, and subjective mental health status. Stress levels were significantly different by subjective physical health status, subjective mental health status, social relationship satisfaction, and satisfaction levels of nursing major and university. A significant relationship between sleep quality and stress (r= .45, p< .001) was found, meaning that a lower quality of sleep was significantly correlated with higher stress level. Conclusion: The results indicated that most nursing students had sleep problems and stress. Therefore, interventions are needed to be developed to lower the level of stress and increase the quality of sleep among nursing students.