• Archives of Pharmacal Research
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• v.25 no.2
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• pp.178-183
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• 2002

A high molecular ar weight water-soluble chitosan (WSC) with an average molecular weight of 300 kD and a deacethylation level of over 90% was produced using a simple multi-step-membrane separation process. It is known that WSC prevents obesity induced by a high-fat diet. Consequently, this study investigated whether or not WSC improved the ovarian dysfunction caused by obesity in mice. The mice were fed a high density protein and lipid diet for weeks, followed by the administration of WSC at 480 mg/kg body weight per day for 4 days. Thereafter, the changes in body weight, ovulation rate, in vivo and in vitro fertilization and emboryonic development were measured . WSC markedly reduced the body weight of obese mice fed with a high-fat diet, but not in mice fed with a normal diet. WSC had siginificant effects on the ovulation rate, both the in vivo and in vitro fertilization rates and embryonic development. These results indicate an improvement in the ovarian and oviduct dysfunction caused by obesity, and suggest an adjustment in the internal secretions and metabolic functions.

• Journal of applied mathematics & informatics
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• v.36 no.1_2
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• pp.93-105
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• 2018

There are many metric functions in the plane. In this paper we are to classify the metric functions on the plane using two ways such as using sum of distances between some points when start point and end point is fixed, and using area of transferred triangle consisted of distances between 3 points.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3810-3816
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• 2012

Here we report our recent result of a new semiconductor material, which has an asymmetric structure. The synthesized molecules consist of anthracene and thiophene connected by bridged ethylene and substituted with hexyl or dodecyl groups as pendants. The semiconductors were synthesized using a McMurry coupling reaction between anthracene-2-carbaldehyde and corresponding 5-hexyl(or dodecyl)thiophene-2-carbaldehyde. A first investigation of synthesized asymmetry AVHT (9a) and AVDT (9b) for the physical properties showed that they have high oxidation potential and thermal stability. The devices prepared by using AVHT (9a) and AVDT (9b) showed the mobility of $2.6{\times}10^{-2}cm^2/Vs$ and $4.4{\times}10^{-3}cm^2/Vs$, respectively, in solution processed OTFTs.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3875-3878
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• 2012

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.2
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• pp.91-102
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• 2012

Metabolomics is the systematic identification and quantification of all metabolites in an organism or biological sample. NMR has been used as a major application tool in plant metabolomics such as quality control, chemotaxonomy, and analysis of genetically modified plants. Herbal medicines are the important therapeutics and are used to manage common diseases such as cold, inflammation, pain, heart diseases, liver cirrhosis, diabetes and central nerve system diseases. Herb plants include various kinds of species such as geranium, mint, and thyme and so on and contain different kinds of metabolites. We performed NMR-based metabolomics study on the seven different species of herb plants using $^1H$ NMR experiments and OPLS-DA to understand the correlation between the classification of herb plants and their metabolite contents. This study showed clear metabolic discrimination among various herb plants. This metabolmics study found several diagnostic NMR signals which are able to be used as bio-markers for identification of the specific herb plants among various species. Clear metabolic discrimination of herb plants suggests three chemotaxonomic groups of herb species.

• Journal of the Korean Society of Earth Science Education
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• v.1 no.1
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• pp.41-51
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• 2008

For teaching-learning to geological region of earth science part in science education, middle school, the practical uses of natural science museum are very effective. So, the appropriate uses of the natural science museum are necessary for the teaching and learning of Science Education. This study aims to consider the presentation characteristics of the natural science museum and to examine how is effective it to geological region in middle school science curricula on those uses. From the results, the natural science museum is low in multi-sided and open-endedness presentation characteristics but high in ones of accessible characteristic. And its presentations are good in multimodal characteristics using supported materials but relatively low in relevant and multimedia ones. In the museum, diorama and self-performing presentation types are not but internet ones are most. The presentations of the natural science museum are mainly assigned to knowledge region linked to basic science concepts but relatively insufficient in STS aspects, on the basis of connection the presentations with middle school science curricula. It is respected that these insufficiencies might be diminished by variable arrangements of and explanations to the presentations for understanding improvements. And, applies to the presentations in STS may be encountered, if multi-sided observations to them is available.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.183-187
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• 2014

Lead zirconate titanate (PZT) is significant material in electrical and optical devices for their ferroelectric, piezoelectric and dielectric properties. In this research, PZT films were fabricated by reactive RF co-sputtering method using Pb, Zr, and Ti targets. From XPS study, lead, zirconium, and titanium are successfully deposited on Si(100) substrate. Thickness of PZT films was measured with a surface profiler and the thickness was decreased as the oxygen gas ratio increased in the sputter gas.

• Journal of Science Education
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• v.37 no.2
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• pp.405-415
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• 2013

The purpose of this study was to investigate high school students in natural science track and engineering major university students' perceptions about the writing and composition education. A total of 318 high school students in natural science track from two high schools in a metropolitan area and 447 university students majoring in engineering from three universities participated in the survey and asked to response their perceived status and needs of writing education for science-engineering track. The survey instrument, developed by Lee et al.(2009), was used for this study. The data was analyzed through the SPSS 18.0 program for Windows for Multiple Response Frequency Analysis, Descriptive Statistics, Independent Samples t-test, and One-way Analysis of Variance. The results indicated that high school students relatively perceived that writing education was less necessary compared to university students. In addition, high school students found writing less difficult than university students do. In related to studying their experience with writing and composition education, almost no high school students have taken writing classes and university students have taken an average of one class. Most university students who took writing classes took basic writing classes that were not programmed for students in Science and Engineering. In the basic survey to revitalize writing and composition education for Science and Engineering students in different majors, the level of writing and composition education required by students in each major was different. Writing was considered most necessary for students majoring in Chemical Engineering, followed by students majoring in Mechanical Engineering and Electronic Engineering. The study of writing and composition education for high school and college should extend to studies on teachers or professors who teach writing, studies on contents and methods of writing education, and studies on the development of writing programs for different majors in university.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1611-1615
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• 2009

We designed new anthracene-based host material to increase color purity as well as device efficiency. The new blue host, 9,10-bis(2,4-dimethylphenyl)anthracene (BDA), has highly twisted structure and wide band gap due to ortho interaction between anthracene and introduced 2,4-dimethylphenyl substituents. BDA exhibited deep blue fluorescence in solution (${\lambda}_{max}$ = 410 nm) and in solid state (${\lambda}_{max}$ = 429 nm), respectively, with the wide optical band gap (E = 3.12 eV). Blue-light-emitting OLEDs using obtained host and 2% Flu-DPAN as emitter showed 8 cd/A of high efficiency as well as high color purity [CIE coordinates = (0.15, 015)].

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1103-1108
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• 2010

This study was conducted to be used as basic data of environmental friendly construction planning by comparing and analyzing thermal environment, find particles and biotope area rate according to land cover types of outside space of schools located in Chung-ju. When meteorological factors were analyzed according to land cover types, for temperature planting area and paved area showed low-and high-temperature ranges, respectively, and relative humidity was negatively related with temperature as low-and high-temperature ranges corresponded to high-and low-humidity ranges, respectively. For Wet Bulb Globe Temperature Index (WBGT) by land cover types, it was observed to be artificial grass> bare land> natural grass. Find particles were different according to land cover types of playground with being bare land> artificial grass> natural grass in the order. Bare land playground, where there were artificial factors and no absorption of fine particles through stomata of leaves as a function of natural circulation, recorded the highest level of $39.8\;{\mu}g/m^3$ and the level was relatively higher compared to the levels by season in Chung-ju. Biotope area rate showed the order of M elementary school> K elementary school> C commercial high school. That was considered to be caused by the difference of land cover type of school playground accounting for a large part of a school.