• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.890-894
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• 2001

The isolation of genomic DNA from mammalian cells is usually performed by cell lysis followed by protein digestion, extraction, and finally, ethanol precipitation of the chromosomal DNA. However, in the case of large sample numbers or when only small amounts of starting materials are available, such conventional methods are not efficient and are cumbersome to be applied. Some alternative methods have been described as well as having commercial DNA isolation kits to be available, nevertheless, there is room left for much improvement. In the present study, a novel method is introduced, where it simplifies conventional protocols by omitting some time-consuming steps such as protease incubation or DNA precipitation and its resuspension. Using paramagnetic silica resins, the genomic DNA was purified over a magnetic field, and the bound DNA was eluted with a low-salt buffer. The fidelity and effectiveness of this novel method was determined by using normal and apoptotic cells as a starting material and then compared to other protocols. The high speed and convenience along with its high efficiency in detecting apoptotic chromosomal DNA will prove this method to be an improved alternative in the isolation of genomic DNA from mammalian cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.364.2-364.2
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• 2014

Magnesium oxide (MgO) thin films have attracted great scientific and technological interest in recent decades. Because of its distinguished properties such as a wide band gap (7.2 eV), a low dielectric constant (9.8), a low refractive index, an excellent chemical, and thermal stability (melting point=$2900^{\circ}C$), it is widely used as inorganic material in diverse areas such as fire resistant construction materials, optical materials, protective layers in plasma display panels, buffer layers of multilayer electronic/photonic devices, and perovskite ferroelectric thin films. Precursor used in the ALD requires volatility, stability, and low deposition temperature. Precursors using a heteroleptic ligands with different reactivity have advantage of selective reaction of the heteroleptic ligands on substrate during ALD process. In this study, we have synethesized new heteroleptic magnesium precursors ${\beta}$-diketonate and aminoalkoxide which have been widely used for the development of precursor because of the excellent volatility, chelating effects by increasing the coordination number of the metal, and advantages to synthesize a single precursor. A newly-synthesized Mg(II) precursor was adopted for growing MgO thin films using ALD.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.12-15
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• 2002

The first purpose of present study was to compare the anticariogenic effect of compomer, resin modified glass ionomer cement and composite (RMGIC). The second purpose was to evaluate the recently introduced methods, which use confocal scanning micro-scope, in detecting initial caries around restoration. 2$\times$4$\times$1.5mm cavities were prepared from the recently extracted 50 human teeth on the buccal or lingual surface. The prepared teeth were randomly devided into 5 groups and restored with each filling material. Group 1: Dyract AP, Group 2: compoglass F, Group 3: F2000, Group 4: Z100. Group 5:Fuji II LC. The teeth were stored for 30 days in the distilled water, then stored in the buffer solution for artificial caries development: pH 4.3, lactic acid 100 mM, calcium 16 mM, phosphate 8mM, sodium azide 3mM. Then, the samples were sectioned longitudinally and examined with confical scanning microscope. The results showed that the use of compomer and resin modified glass ionomer cement showed caries inhibition zone whereas the composite did not. There was no difference in the width of caries inhibition zone between compomers and RMGIC. The confocal scanning microscope was useful in detecting initial caries around restoration.

• Korean Journal of Organic Agriculture
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• v.9 no.4
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• pp.71-93
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• 2001

Within the paper, an overview of organic farming in Europe countries is given and the Principle and skills of organic agriculture is shortly reported with special regard to Germany. The overview information on European organic forming is covered such as \circled1 development of organic farming, \circled2organic farming organizations, \circled3standards and certification, \circled4implementation of EU council regulation, \circled5state support, \circled6implementation of Agenda 2000, \circled7training and education, \circled8advisory service and research situation. In the paper the principle and skills for organic farming which are practiced actually in the German organic farms is also reported. How to maintain and increase the fertility and microbiological activity of the soil by \circled1cultivation of legumes, green manures or deep-rooting crops in multi-annual rotation system, \circled2incorporation in the soil organic material, by-products from livestock farming is one of the major principle to organic crop production. Pest and diseases and weeds are controlled by any one, or a combination of the following measure ; \circled1choice of appropriate species and varieties, \circled2appropriate rotation programs, \circled3mechanical cultivation, \circled4protection of natural enemies of pests through provision of favourable habitat and ecological buffer zone, \circled5diversified ecosystems, \circled6flame weeding, \circled7natural enemies, \circled8bio-dynamic preparations, \circled9mulching and mowing, \circled10grazing of animals, ⑪mechanical controls, ⑫steam sterilization.

• Journal of Sensor Science and Technology
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• v.13 no.3
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• pp.169-174
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• 2004

A fiber optic pH sensor has been fabricated using nile blue entrapped in an ammonia catalyzed silica sol-gel film coated on glass substrate by dip-coating. The sensor was fixed on the end of an optical fiber. The sensor showed pH sensitivity when dipped into liquids at different pHs. Linear and reproducible responses were obtained in standard buffer solutions in the pH range $6.0{\sim}8.5$, which encompasses the clinically-relevant range. The effects of interferences on the determination of pH were also investigated. The sensors were successfully applied to the determination of pH in different commercial ionic drinks.

• Nuclear Engineering and Technology
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• v.23 no.4
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• pp.410-419
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• 1991

Four domestic bentonite samples collected from the south-eastern area of Korea were identified as Ca-bentonite by analysing XRD-patterns and chemical compositions. By comparing the surface area, CEC and the swelling rate of these samples, Dong-Hae A was selected as a suitable sample for the investigation of distribution coefficients. Sorption equilibrium of Cs, Co and Am was reached in around 10 days, but that of Sr was found to be much earlier. From the measured distribution coefficients, the domestic bentonite was found to have high sorption capacity. In the effect of varying concentration on the distribution coefficient, the values of radionuclides peaked at about 10$^{-7}$ mo1/$\ell$ of concentration.

• Nuclear Engineering and Technology
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• v.45 no.1
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• pp.53-60
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• 2013

Bentonite is generally used as a buffer material in high-level radioactive waste disposal facilities and consists of 50% quartz by weight. Quartz strongly affects the behavior of bentonite over very long periods. For this reason, quartz dissolution experiment was performed under high-pressure and high-alkalinity conditions based on the conditions found in a high-level radioactive waste disposal facility located deep underground. In this study, two quartz dissolution experiments were conducted on 1) quartz beads under low-pressure and high-alkalinity conditions and 2) a single quartz crystal under high-pressure and high-alkalinity conditions. Following the experiments, a confocal laser scanning microscope (CLSM) was used to observe the surfaces of experimental samples. Numerical analyses using the finite element method (FEM) were also performed to quantify the deformation of contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress field, as indicated by the quartz deformation of the contact area through the FEM analysis. According to the numerical results, a high compressive stress field acted upon the neighboring contact area, which showed a rapid dissolution rate compared to other areas of the sample.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.67-72
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• 2008

Al-doped p-type ZnO thin films were fabricated by RF magnetron sputtering on n-Si (100) and homo-buffer layers in pure oxygen ambient. ZnO ceramic mixed with 2 wt% $Al_2O_3$ was selected as a sputtering target. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are arranged from $1.66{\times}10^{16}$ to $4.04{\times}10^{18}\;cm^{-2}$, mobilities from 0.194 to $198\;cm^2V{-1}s^{-1}$ and resistivities from 0.0963 to $18.4\;{\Omega}cm$. FESEM cross section images of different parts of a p-type ZnO:Al thin film annealed at $800^{\circ}C$ show a compact structure. Measurement for same sample shows that density is $5.40\;cm^{-3}$ which is smaller than theoretically calculated value of $5.67\;cm^{-3}$. Photoluminescence (PL) spectra at 10 K show a shoulder peak of p-type ZnO film at about 3.117 eV which is ascribed to electron transition from donor level to acceptor level (DAP).

• Transactions on Electrical and Electronic Materials
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• v.12 no.4
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• pp.169-173
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• 2011

In this study, Al-N codoped p-type zinc oxide (ZnO) thin films were deposited on Si and homo-buffer layer templates in a mixture of $N_2$ and $O_2$ gas with ceramic ZnO:(2 wt% $Al_2O_3$) as a sputtering target using DC- magnetron sputtering. X-ray diffraction spectra of two-theta diffraction showed that all films have a predominant (002) peak of ZnO Wurtzite structure. As the $N_2$ fraction in the mixed $N_2$ and $O_2$ gases increased, field emission secondary electron microscopy revealed that the surface appearance of codoped films on Si varied from smooth to textured structure. The p-type ZnO thin films showed carrier concentration in the range of $1.5{\times}10^{15}-2.93{\times}10^{17}\;cm^{-3}$, resistivity in the range of 131.2-2.864 ${\Omega}cm$, and mobility in the range of $3.99-31.6\;cm^2V^{-1}s^{-1}$ respectively.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.182-189
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• 2000

The issue of food security will become one of the most widely concerned area of public policy in North East Asia coming 21st century. Although those countries such as China, Japan, South and North Koreas and Mongolia places emphasis on the need to have stable and reliable capacity for food production, it will be highly possible for these regions to experience the shortage of food supply due to growing population, expanding urbanization and rapid industrialization within next decade. Since world food markets are characterized as unstable structure and dominated by large multinational firms, their reliances on importing staple food may create the aggravation of food shortage problem in emergency situations. One possible proposal for solving food security in north-east region might be movements toward multilateral food supply assurance agreements as a component of trade negotiations among these countries. As measures for cooperation for securing food supply in these regions, following principles would be suggested; 1) encouraging agricultural cooperation based on private business, 2) exchange of technical and human resources rather than material support, 3) developing mutual concern and benefits, 4) managing joint buffer stock for staple food.