• Applied Microscopy
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• 제24권1호
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• pp.102-113
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• 1994

A thin section of the methanogenic archaebacterium, Methanoplanus limicola, shows that the surface glycoprotein array (S-layer) is separated from plasma membrane by a distinct inter-space, approximately 4.0-6.0nm wide. We report our structural study of the S-layer by electron crystallographic techniques. Image analysis and thin sections of the S-layer treated with and without triton disclosed that retention of the single layer crystal requires the presence of detergent to avoid hydrophobic bonding.

• 환경생물
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• 제21권3호
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• pp.297-302
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• 2003

This study was designed to determine whether selenium (Se) nutrition affects pulmonary glutathione peroxidase and alveolarization in the neonatal rat. Twenty-four female Sprague Dawley rats were bred and fed a semipurified Se-deficient (0.04 ppm, Se-) or a Se-adequate (0.5 ppm, Se+) diet through pregnancy and lactation. Pulmonary DNA synthesis was slightly higher in Se+ pups than in Se- pups on d 6 and d 9 of lactation, but significant difference was not found. As pulmonary alveolarization progressed, mean air space size decreased and internal surface area and lung volume increased. No difference in pulmonary alveolarization was found between Se- and Se+ pups by age. Pulmonary Se concentration was higher in Se+ pups than in Se- pups at all age. Glutathione peroxidase activity in lung tissur reflected Se status and was lower in Se- pups than in Se+ pups. In conclusion, selenium has no significant effect on alveolarization of neonatal lungs. but it is necessary for adequate supply of pulmonary antioxidant, glutathione peroxidase.

• 한국주거학회논문집
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• 제10권4호
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• pp.161-174
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• 1999

This study tried to search for solutions of present problems in architecture through interdisciplinary study which includes biology, literature, aesthetics, and psychology, and set up two models composed of the nature and the human perception which contemporary architecture has problems on. By nature-oriented approach through biology and romanticist literature, the five types of organic principles which could be obtained from structure and order in natural system and by human perception-oriented approach through aesthetic theory of Harold Osborne and perceptual and cognitive psychology the structure and order of perceptual arousal, perceptual balance, and perceptual order in human cognition based on perceptual appropriateness could be found. The unified and organic framework of architectural composition must be considered through a deductive and inductive study as this study was approached. The results of the present study can be applied to construct human-oriented design principles and factors in architectural space and form, and better environmental quality.

• Mycobiology
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• 제37권3호
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• pp.243-246
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• 2009

In this study, the antifungal activities of limonene against Trichophyton rubrum were evaluated via broth microdilution and vapor contact assays. In both assays, limonene was shown to exert a potent antifungal effect against T. rubrum. The volatile vapor of limonene at concentrations above $1{\mu}l$/800 ml air space strongly inhibited the growth of T. rubrum. The MIC value was 0.5% v/v in the broth microdilution assay. The antifungal activity of limonene against T. rubrum was characterized as a fungicidal effect.

• Journal of Plant Biology
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• 제37권3호
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• pp.285-292
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• 1994

Ultrastructural changes in Panax ginseng C. A. Meyer mesophyll chloroplasts and variation of thylakoid membrane protein in responce to the light intensity were studied in leaves of two-y-old plants exposed to two different light intensities under field coditions. The leaves were allowed to function for three months after emergence under two contrasting light conditions. The ginseng chloroplasts of 5% light were filled with highly stacked grana of condensely arrayed thylakoids, so that the stroma space was hardly observed. In contrast, chloroplasts from leaves at 100% sunlight had fewer thylakoid membranes and smaller grana stacks. The number of osmiophilic globules increased. Total Chl content and Chl b content were lower at 100% sunlight than 5% sunlight. The thylakoid membrane proteins in the leaves grown at 100% sunlight showed lower CPIa, LHCII and CP29 than those with 5% sunlight. This effect was most obvious for LHCII. Polypeptides showed major bands at 90, 64, 29-30, 22 and 14 kD, and minor bands at 59, 58, 54, 52, 49, 46, 44, 35, 23, 21 and 18-19 kD. All these bands were lower in intensity in the leaves exposed to 100% sunlight. Moreover, the bands at 58-59, 46-47 and 23 kD disappeared.

• Plant Resources
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• 제5권1호
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• pp.7-16
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• 2002

The purposes of this study were to clarify of floristic composition and the landscape structure on the habitats of each Ranunculus plant, which were distributed in Daejeon, Korea. Three taxa were distributed and investigated in this study. Floristic composition of habitats were organized by living in flatten open space needed a lot of sunlight and humidity species. Landscape ecological structure of habitats were defined by soils of coarse loamy and loamy skeletal, slope of under 15$^{\circ}$, under the (five percent of woody coverage at 100-300m above the sea levels. Distribution patterns of Ranunculus plants in Daejeon were presented on the 1km X 1km grid map.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.312-326
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• 2021

The prey-predator model is one of the most influential mathematical models in ecology and evolutionary biology. In this study, we considered a modified prey-predator model, which describes the rate of change for each species. The effects of modifications to the classical prey-predator model are investigated here. The conditions required for the existence of the first integral and the stability of the fixed points are studied. In particular, it is shown that the first integral exists only for a subset of the model parameters, and the phase portraits around the fixed points exhibit physically relevant phenomena over a wide range of the parameter space. The results show that adding coupling terms to the classical model widely expands the dynamics with great potential for applicability in real-world phenomena.

• Genomics & Informatics
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• 제20권1호
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• pp.10.1-10.15
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• 2022

Human exposure to pollutants has been on the rise. Thus, researchers have been focused on understanding the effect of these compounds on human health, especially on the genetic information by using various tests, among them the somatic mutation and recombination tests (SMARTs). It is a sensitive and accurate method applicable to genotoxicity analysis. Here, a comprehensive bibliometric analysis of SMART assays in genotoxicity studies was performed to assess publication trends of this field. Data were extracted from the Web of Science database and analyzed by the bibliometric tools HistCite, Biblioshiny (RStudio), VOSViewer, and CiteSpace. Results have shown an increase in the last 10 years in terms of publication. A total of 392 records were published in 96 sources mainly from Brazil, Spain, and Turkey. Research collaboration networks between countries and authors were performed. Based on document co-citation, five large research clusters were identified and analyzed. The youngest research frontier emphasized on nanoparticles. With this study, how research trends evolve over years was demonstrated. Thus, international collaboration could be enhanced, and a promising field could be developed.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.191-196
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• 2005

Genetic networks are a key to unraveling dynamic properties of biological processes and regulation of genes plays an essential role in dynamic behavior of the genetic networks. A popular characterization of regulation of the gene is a kinetic model. However, many kinetic parameters in the genetic regulation have not been available. To overcome this difficulty, in this report, state-space approach to modeling gene regulation is presented. Second-order systems are used to characterize gene regulation. Interpretation of coefficients in the second order systems as resistance, capacitance and inductance is studied. The mathematical methods for transient response analysis of gene regulation to external perturbation are investigated. Criterion for classifying gene into three categories: underdamped, overdamped and critical damped is discussed. The proposed models are applied to yeast cell cycle gene expression data.

• Applied Microscopy
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• 제3권1호
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• pp.39-44
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• 1973

The effects of morphine HCl on the mesenteric mast cells were studied the electron microscopy. The results of the observations are as follows: 1. In the experimental group for intravenous injection of morphine HCl 12 mg/kg, the granules appeared cluster, granular lysis and an electron transparent appearance. Frequently, some granules appeared in the extracellular space. 2. In the experimental group for intravenous injection of morphine HCl 24 mg / kg, it was observed. that the formation of a clear halo or a space around each granule. Many altered granules showing a reticular texture (type 2) are observed in the cytoplasm. 3. From the results mentioned above, it is suggested that rat mesenteric mast cell' granules were affected by morphine HCl.