• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.2979-2984
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• 2014

Silver nanoparticles have been synthesized by liquid-phase and alcohol reduction methods. Silver-doped silica-complex nanoparticles were prepared using a sol-gel process. The formation, structure, morphology, and particle size of the nanoparticles have been studied using several techniques. Silver nanoparticles of size of 30-40 nm were formed successfully by alcohol reduction. TEM images show that both the concentration and the molecular weight of polyvinyl pyrrolidone (PVP) considerably affect the size of the emerging silver nanoparticles. The number of silver-doped silica-complex particles increased by a mercapto-group treatment that showed a narrower size distribution than that of silica treated with amino groups. The silver/polyester and silver-doped silica/polyester masterbatch chips showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli.

• Journal of Ginseng Research
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• 제38권1호
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• pp.78-81
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• 2014

The single oral administration of red ginseng oil (5000 mg/kg) to Sprague-Dawley rats induced no changes in behavioral patterns, clinical signs, and body weight, and hepatotoxicity parameters such as aspartate aminotransferase and alanine aminotransferase for 14 d. Therefore, these results suggest that the red ginseng oil is safe and nontoxic acutely.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.345-346
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• 2014

• 한국생활과학회지
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• 제21권6호
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• pp.1017-1028
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• 2012

The purpose of this study was to evaluate the relationship between fetus-related pregnancy stress and temperament, parenting attitude, parent-fetal attachment, and marital quality. Respondents were 285 pregnant women and their spouses who participated in Pregnant Education Programs. Data was collected by means of questionnaire. The results are summarized as follows: The total fetus-related pregnancy stress level of pregnant couples demonstrated a higher relationship while parent-fetal attachment level demonstrated a very significant relationship. There were significant differences between spouses with regard to fetus-related pregnancy stress, parenting attitude, parent-fetal attachment, and marital quality.

• Perspectives in Nursing Science
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• 제10권1호
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• pp.41-51
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• 2013

Purpose: This study was performed to understand the characteristics and the meaning of the illness experience of breast cancer survivors as basic data for the development of an intervention program. Methods: The participants were 25 breast cancer survivors who had completed treatment at a tertiary hospital in Seoul. Data were collected through in-depth and unstructured audio-recorded interviews by the investigator. The participants were asked to describe their illness experience. The data were analyzed according to Giorgi's method for phenomenological analysis. Results: The interview data were organized by theme into 6 categories that emerged from the analysis. The themes were acceptance of the illness, active coping with reality, gaining strength through the support of surrounding people, struggling to overcome a negative mindset, self-reflection, and the pursuit of a meaningful new life. Conclusion: We recommend the development of a survivorship program based on self-reflection, which can engender self-transcendence and spiritual well-being.

• Carbon letters
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• 제16권1호
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• pp.11-18
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• 2015

The process of oxidizing polyacrylonitrile (PAN)-based carbon fibers converts them into an infusible and non-flammable state prior to carbonization. This represents one of the most important stages in determining the mechanical properties of the final carbon fibers, but the most commonly used methods, such as thermal treatment ($200^{\circ}C$ to $300^{\circ}C$), tend to waste a great deal of process time, money, and energy. There is therefore a need to develop more advanced oxidation methods for PAN precursor fibers. In this review, we assess the viability of electron beam, gamma-ray, ultra-violet, and plasma treatments with a view to advancing these areas of research and their industrial application.

• Carbon letters
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• 제23권
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• pp.17-21
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• 2017

Polyurethane (PU) nanofibers containing graphene oxide (GO) and Ag doped functionalized reduced graphene oxide (Ag-RGO) were successfully prepared via the electrospinning technique. The uniform distribution of GO sheets along with Ag nanoparticle in the nanofibers was investigated by scanning electron microscopy and the elemental mapping technique. X-ray diffraction and thermal gravimetric analysis verified the presence of GO and Ag in the bicomposite nanofibrous mats. Antibacterial tests against Escherichia coli demonstrated that the addition of GO and Ag-RGO to the PU nanofiber greatly enhanced bactericidal efficiency. Overall, these features of the synthesized nanofibers make them a promising candidate material in the biomedical field for applications such as tissue engineering, wound healing, and drug delivery systems.

• 아동학회지
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• 제23권4호
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• pp.137-152
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• 2002

In response to a growing trend toward downward escalation of public school curriculum, the present study surveyed so-called extracurricular activities in kindergartens and analyzed teacher's perception of these activities. Questionnaires were mailed to 1300 private kindergartens and 1116 responses were received. Major findings were that over 89% of the respondents reported doing extracurricular activities in their kindergartens, mostly using 3-4 different kinds of special activities. The 3 most highly ranked lessons in order of frequency were English, art and physical activity. Whole group time was most often used for extracurricular activities. Kindergarten teachers were concerned with the qualifications of teachers for these activities. Teachers of these extra activities usually have no specialized training or supervised experience working with 3-through 5-year-old children.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2441-2445
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• 2013

Chitosan non-woven fabrics were acetylated to improve their antimicrobial properties. The active chlorine content, antimicrobial properties, storage stability, and surface properties of acetylated chitosan non-woven fabrics were investigated. The active chlorine content of the fabrics increased upon reduction of the degree of the acetylation or increase in sodium hypochlorite concentration. Acetylated chitosan non-woven fabrics showed powerful antimicrobial activity by efficiently killing Escherichia coli and forming a growth inhibition zone for Staphylococcus aureus. Furthermore, scanning electron microscopy observations demonstrated that the acetylated chitosan non-woven fabrics were not damaged in sodium hypochlorite solution.

• 천문학논총
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• 제30권2호
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• pp.525-527
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• 2015

We prepare a catalog of the morphological types of 5840 galaxies within z = 0.01. We determine the morphological types by visual inspection using color images from the Sloan Digital Sky Survey (SDSS) DR7. The majority of the sample galaxies are SDSS spectroscopic target galaxies, but we add ~ 900 galaxies whose redshifts are available in the NASA Extra Galactic Database (NED). The fraction of elliptical and lenticular galaxies is ~ 0.06 while spiral galaxies comprise ~ 30% of the sample with a bar fraction of ~ 0.6. About half of sample are dwarf galaxies of which ~ 35% are dwarf elliptical-like galaxies. There is a strong correlation between the morphological types and luminosities of the galaxies, i.e., high luminosities in the early type galaxies and low luminosity in the late type galaxies. The mean luminosity of dwarf elliptical-like galaxies is similar to that of irregular galaxies.