• Plant Biotechnology Reports
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• v.4 no.2
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• pp.117-123
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• 2010

We used a flow cytometer to investigate the variations in endopolyploidy (the frequencies of nuclei with DNA contents equivalent to 4C through 16C) during the short period of the early growing stage in vigorously growing young tissues of maize seedlings. We examined different portions of the root and leaves that had been growing for 7 (day 7) and 13 (day 13) days after germination. Endoreplication showed two opposing phenomena without aging. In one case, the endopolyploidy of the first leaf was higher on day 13 than on day 7. In the latter case, endopolyploidy decreased, as clearly revealed by a comparison of the endopolyploidy of the second leaves and the 160-170 mm portion of the seminal root on days 7 and 13. Endopolyploidy was also lower in the top of the leaf. In roots, endopolyploidy was increased by the exogenous application of abscisic acid for only 1 day. The levels of endopolyploidy increased without an increase in cell size in the roots. These results showed that endoreplication occurs in actively growing and young tissue and that the variation can be induced in the short period examined.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.826-833
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• 2014

Driven by both environmental and economic reasons, the development of small to medium scale GTL(gas-to-liquid) process for offshore applications and for utilizing other stranded or associated gas has recently been studied increasingly. Microchannel GTL reactors have been prefrered over the conventional GTL reactors for such applications, due to its compactness, and additional advantages of small heat and mass transfer distance desired for high heat transfer performance and reactor conversion. In this work, multi-microchannel reactor was simulated by using commercial CFD code, ANSYS FLUENT, to study the geometric effect of the microchannels on the heat transfer phenomena. A heat generation curve was first calculated by modeling a Fischer-Tropsch reaction in a single-microchannel reactor model using Matlab-ASPEN integration platform. The calculated heat generation curve was implemented to the CFD model. Four design variables based on the microchannel geometry namely coolant channel width, coolant channel height, coolant channel to process channel distance, and coolant channel to coolant channel distance, were selected for calculating three dependent variables namely, heat flux, maximum temperature of coolant channel, and maximum temperature of process channel. The simulation results were visualized to understand the effects of the design variables on the dependent variables. Heat flux and maximum temperature of cooling channel and process channel were found to be increasing when coolant channel width and height were decreased. Coolant channel to process channel distance was found to have no effect on the heat transfer phenomena. Finally, total heat flux was found to be increasing and maximum coolant channel temperature to be decreasing when coolant channel to coolant channel distance was decreased. Using the qualitative trend revealed from the present study, an appropriate process channel and coolant channel geometry along with the distance between the adjacent channels can be recommended for a microchannel reactor that meet a desired reactor performance on heat transfer phenomena and hence reactor conversion of a Fischer-Tropsch microchannel reactor.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.262.1-262.1
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• 2014

Lipid peroxidation induces functional deterioration of cell membrane and induces cell death in extreme cases. These phenomena are known to be related generally to the change of physical properties of lipid membrane such as decreased lipid order or increased water penetration. Even though the electric property of lipid membrane is important, there has been no report about the change of electric properties after lipid peroxidation. Herein, we demonstrate the molecular energy band change in red blood cell membrane through peroxidation by air-based atmospheric pressure DBD plasma treatment. Ion-induced secondary electron emission coefficient (${\gamma}$ value) was measured by using home-made gamma-focused ion beam (${\gamma}$-FIB) system and electron energy band was calculated based on the quantum mechanical Auger neutralization theory. The oxidized lipids showed higher gamma values and lower electron work functions, which implies the change of surface charging or electrical conductance. This result suggests that modified electrical properties should play a role in cell signaling under oxidative stress.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.503-513
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• 2011

Appreciation of nature and an understanding of the biological sciences by the general public are key to the popularization of modern science. In particular, informal and accessible venues such as museum exhibits occupy a crucial role in science education, and they depend heavily on fields related to macrobiology, including Ecology, Animal Behavior, and Environmental Science. Unfortunately, lack of engaged experts and superficial descriptions of natural phenomena all too often prevent scientific knowledge from being shared effectively with the general public. Raw information itself and knowledge are not in a form or structure accessible to nonspecialists. In order to move successfully deliver substantive comprehension of the biological knowledge to the general public, it is necessary to categorize information from a content-conscious perspective and transform it into useful biological content. Therefore, the role of scientists is critically important in a series of processes that include theme selection, editing, and even graphical layout of contents. These processes require not only a scientific and logical way of thinking, but also an aptitude for artistic presentation and effective communication. The concept of Translation is presented as a theoretical and operational framework for the popularization of science.

• Hwankyungkyoyuk
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• v.15 no.2
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• pp.1-13
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• Hwankyungkyoyuk
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• v.15 no.1
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• pp.137-147
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily Impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene Pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• Molecules and Cells
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• v.45 no.8
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• pp.537-549
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• 2022

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9557-9565
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• 2014

MiRNAs are endogenous, single stranded ~22-nucleotide non-coding RNAs (ncRNAs) which are transcribed by RNA polymerase II and mediate negative post-transcriptional gene regulation through binding to 3'untranslated regions (UTR), possibly open reading frames (ORFs) or 5'UTRs of target mRNAs. MiRNAs are involved in the normal physiology of eukaryotic cells, so dysregulation may be associated with diseases like cancer, and neurodegenerative, heart and other disorders. Among all cancers, lung cancer, with high incidence and mortality worldwide, is classified into two main groups: non-small cell lung cancer and small cell lung cancer. Recent promising studies suggest that gene expression profiles and miRNA signatures could be a useful step in a noninvasive, low-cost and repeatable screening process of lung cancer. Similarly, every stage of lung development during fetal life is associated with specific miRNAs. Since lung development and lung cancer phenomena share the same physiological, biological and molecular processes like cell proliferation, development and shared mRNA or expression regulation pathways, and according to data adopted from various studies, they may have partially shared miRNA signature. Thus, focusing on lung cancer in relation to lung development in miRNA studies might provide clues for lung cancer diagnosis and prognosis.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.123-134
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• 1987

The transport phenomena of alkali metal chlorides through poly(2 hydroxyethyl methacrylate) hydrogel membrane have been studied using electrodialysis. The hydrogel membranes were prepared by the polymerization of 2-hydroxvethyl methacrylate in the presence of 45%(V/V) H2O and ethyleneglycodimethacrylate. The initiator used in the polymerization was azobismethylisobutyrate (AMIB) prepared from azobisiobtyronitrile (AIBN) using Mortimer method. The permeability of alkali metal chlorides such LiCl, NaCl and KCI at 50 voltage was obtained. The permeability of NaCl was also observed at 30, 40, 50, and 60 voltages respectively. The concentration of solutes permeated through the membrane was measurer by flame photometry. The experimental results have been discussed with the comparison of apparent solute molecular size, the self-diffusion coefficient of solutes, the transport number of cations in aqueous solution. These indic aloes that poly(2 hydroxyethyl methacrylate) hydrogel membrane shows a specific selectivity for sodium ion.

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.811-819
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• 1989

There have been many studies on the biological phenomena of Bioglasses, which nay be used as implant materials in human body. However, not many works on the Bioglass compositions have been reported. In the present study, the effect of Al2O3 substitution for SiO2 in Bioglass of Na2O-CaO-P2O5-SiO2 system on its structure and properties was examined. Infrared and Raman spectroscopic studies for the glass structural analysis, differential thermal analysis and X-ray diffraction analysis for crystallization of the glass were perfomed. Several physical properties, such as thermal expansion coefficient, softening point, microhardness and reaction phenomena, were also measured. The major crystalline phase, after heat treatment of the glasses, was Na2Ca2(SiO2)3 and the crystal was transformed into other phase with increased substitution of Al2O3. The added Al2O3 reduced non-bridging oxygen in glass structure and thermal expansion coefficient, but increased glass density, sofening point and microhardness. When the glasses are reacted in Tris-buffer solution, the substituted Al2O3 inhibited the formation of hydroxyapatite on the Bioglas surface, and no hydroxyapatite was formed for the sample which contained more than 6wt.% of Al2O3 even if they were reacted for 600 hours.