• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1217-1223
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• 2007

I investigated the reproduction system of nine natural populations of P. discolor in Korea and two Mongolian P. conferta populations. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Multivariate principal component analyses (PCA) were conducted to detect differences among populations consid-ering several characters simultaneously of variances using the statistical analysis system. 19 morpho-logical characteristics between Korean Potentilla species and Mongolian Potentilla species showed a slight heterogeneity of variance. The length of internodes (LFL and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two species (P<0.05). The number of ra-mets in P. conferta decreased with increasing geographic distance from viviparity. However, P. discolor has most ramets at distance intervals $60{\sim}80$ cm. In light conditions, P. discolor was significantly less resilience than P. conferta. In drought conditions, although there was not shown significant difference, P. conferta was less resilience than P. discolor. The core analysis indicates that P. conferta is the more resistant species than P. discolor and usually propagates by clonal growth during several strong envi-ronmental disadvantages such as drought events.

• Applied Microscopy
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• v.32 no.2
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• pp.149-156
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• 2002

For investigation of the activated carbon in the rat liver toxicated by lead. Aniamls used $7{\sim}8$ weeks to Sparague-Dewley rat (150 g). The lead acetate (500 ppm) were injected and activated carbon (40 mg/kg) were treated orally for four and eight weeks, respectivelly, and observed by the electron microscope. The group with only lead for 4 weeks, The mitochondria and rough endoplasmic reticulum (rER) were extended and ribosomes dropped from the rER. The group with lead-activated carbon for 4 weeks, The number of lysosomes increased. The shapes of nucleus and rough endoplasmic reticulum observed almost similar with nomally. The group with only lead for 8 weeks, The mitochondria and rough endoplasmic reticulum (rER) were more extended. The group with lead-activated carbon for 8 weeks, the nucleus and rough endoplasmic reticulum was observed nomally.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.156-159
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• 2006

A base substitution was introduced at the position 789 in Escherichia coli 16S rRNA, which was previously identified as an invariant residue for ribosome function and the ability of the mutant ribosomes to translate chloramphenicol acetyltransfernse mRNA was measured by determining the degree of resistance to chloramphenicol of cells expressing these mutant ribosomes. As expected, mutant ribosomes containing a base sub-stitution at the position 789 showed significantly reduced protein-synthesis ability and to identify a functional role played by this residue in protein synthesis, we developed an efficient genetic method to select second-site revertants in 16S rRNA that restore protein-synthesis function to these mutant ribosomes.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.93-96
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• 2011

It has been shown that a nucleotide substitution at position 770 in Escherichia coli 16S rRNA, which is implicated in forming the evolutionary conserved B2c intersubunit bridge, has a detrimental effect on ribosome function. In order to isolate second-site revertants that complement ribosomes containing C770G, we performed a random mutagenesis of the 16S rRNA gene and selected clones that could produce more CAT protein translated by specialized ribosome. One of the clones contained two nucleotide substitutions at positions 569 and 904 (C569G and U904C) and these mutations partially complemented the loss of protein-synthesis ability caused by C770G. Further studies using the isolated revertant will provide information about which part of 16S rRNA is interacting with C770 and the consequence of the structure formed by these interactions in the process of protein synthesis.

• Journal of the Korean Chemical Society
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• v.43 no.2
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• pp.193-198
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• 1999

The transfection efficiency of plasmid DNA was inspected using multi-cationic polymer, 5, 10, 25 and 50KD polyethylenimine (PEI). The optimal neutralization ratio of PEI/DNA complexes by agarose assay was 1.5-2.0 (nmol/nmol) without much difference in molecular weight of PEI.In vitro transfection assay, most of PEI-mediated plasmid delivery was better compared to the naked DNA. Especially, 25KD PEI at optimal condition gave higher transfection rather than the standard assay of DEAE-dextran or Lipofectin. To enhance the cell targeting delivery, the liposome formulations were introduced using phospholipids. As a result, PC/PE liposomes increased 2-2.5 times of the transfection efficiency of PEI single or PC/PE single delivery, but not the case of 25KD PEI. Moreover, the DOTAP/PE-introduced PEI delivery reduced the transfection of DOTAP/PE single delivery. All these results proved that the PEI can be used not only good transfectants and but also good DNA condensing agents in neutral/anionic liposome for cell targeting delivery.

• Korean Journal of Plant Taxonomy
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• v.44 no.1
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• pp.22-32
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• 2014

The petal and sepal micromorphology of five species of Glechoma (Lamiaceae) was investigated to evaluate their taxonomic significance, and a molecular phylogeny using the sequences of internal transcribed spacers (ITS) regions of nuclear ribosomal DNA was carried out to resolve their phylogenetic relationships. Stomatal complexes were mostly found in the inner and outer part of the sepal from all investigated taxa, and the size length of the guard cell was variable among the taxa. Five types of trichomes (uni-cellular non-glandular trichome, multi-cellular non-glandular trichome, short-stalked capitate glandular trichome, long-stalked capitate glandular trichome, and peltate glandular trichome) were variable among the taxa as well as their distribution and density. In molecular phylogenetic studies, the genus Glechoma was composed of three geographically distinct major monophyletic groups (Europe-U.S.A., China-Korea, Japan). G. longituba in Korea and China formed well-supported monophyletic group. G. hederacea in Europe and U.S.A. formed a monophyletic and well-supported clade with G. sardoa, which are endemic species in Italy, with G. hirsuta falling as a sister to this clade. However, G. grandis did not form any phylogenetic relationships with the remaining taxa. The ITS analyses provided taxonomic boundaries of taxa in Glechoma although the petal and sepal micromorphological characters provided weak evidences of the systematic value. As further studies, incorporating more DNA regions to the matrix including other additional morphological analysis will be significant to provide clearer taxonomic structure in Glechoma.

• 주택과사람들
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• s.222
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• pp.48-51
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• 2008

지금 경색에 따른 건설 업계의 유동성 위기가 상당히 심각하다. 이에 반해 정부는 건설 업계가 처한 현 상황을 정확히 인식하지 못한 채 솜방망이 같은 부동산 정책만 내놓고 있다는 불만이 터져나오고 있다. 지난 10월, 건설 업체의 공공 택지와 미분양 아파트 매입에 대한 정책 발표 후에도 건설 업계는 좀 더 강도 높은 대책을 요구하고 있다.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.145-148
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• 2003

The resistance of docosahexaenoic acid (DHA) incorporated $L-{\alpha}-phosphatidyl$ -choline (PC) liposomes against autoxidation was studied for application to food and cosmetic industry. For the preparation of vitamin-C/calcium alginate gel entrapped DHA-PC-liposomes (AVDLs), DHA incorporated PC bilayer was hydrated with vitamin-C containing calcium alginate solution, and the fraction containing liposome was suspended in $CaCl_2$ solution. DHA loading efficiency was calculated by TLC scanning method The morphological examination of AVDLs was performed with transmission electron microscopy (TEM) and lipid peroxidation was measured with an assay for thiobarbituric acid reactive substance (TBARS). DHA loading efficiency was about 17 % of initial loading volume, and when AVDLr containing 0.2 % vitamin C, lipid oxidation was minimized.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.84-89
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• 2003

In order to find a chemical agent which is able to modulate the activity of $H^+-ATPase$, microsomal preparation was obtained from the root tissue of tomato plant and the effect of $La^{3+}$ was measured. The activities of plasma and vacuolar membrane $H^+-ATPase$ were analyzed by the inhibited activities using their specific inhibitors, vanadate and $NO_3-$, respectively. $La^{3+}$ inhibited microsomal ATPases in a dose-dependent manner and the inhibitory effect of $La^{3+}$ was suppressed by both vanadate and $NO_3-$, implying that $La^{3+}$ inhibits both plasma and vacuolar membrane $H^+-ATPase$. The Ki. values of $La^{3+}$which inhibit 50% of the activities of plasma and vacuolar membrane $H^+-ATPase$ were 57 and $78\;{\mu}M$, respectively. The $H^+-ATPase$ of the leaky microsomes made by the treatment of Triton X-100 were also inhibited by $La^{3+}$, suggesting that $La^{3+}$ directly inhibits both enzymes. Meanwhile, the inhibitory effect of $La^{3+}$ was decreased by increasing the concentration of ATP, The effect of ATP was also concentration-dependent and 7 mM ATP completely removed the inhibitory effect of $La^{3+}$. These results imply that $La^{3+}$ inhibits both plasma and vacuolar membrane $H^+-ATPases$ by decreasing the binding affinity of ATP and $La^{3+}$ can be used to control the activity or root $H^+-ATPases$.

• Journal of Korean Society of Forest Science
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• v.107 no.3
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• pp.258-265
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• 2018

This study was conducted to investigate the effective cryopreservation condition of Potentilla discolor Bunge, a rare native plant. Seed viability was more than 80% in PVS2 and PVS3 solution treatments. Seed viability was higher in PVS3 than PVS2 treatment. Seed viability was lower than control in spite of sucrose pretreatment. The germination rate was 95% at 60 min of PVS2 treatment and 30 min of PVS3 treatment but the germination rate was low at other treatments. The growth of the seedling wasn't doing that of the control except for treat PVS2 and PVS3 solution for 30 min. There was no statistically significant difference between the encapsulation method and the vitrification method in the seedling growth between the two cryogenic storage methods. This study is expected to be applied to future conservation methods of Potentilla discolor.