• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.384-389
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• 1992

Bacillus sp. YBL-7 which had been isolated from ginseng root-rot suppressive soil was able to antagonize Fusarium solani causing ginseng root-rot by their antibiotic substance. In order to develop multifunctional antagonist on Bacillus sp. YBL-7 as a biocontrol agent against Fusarium salam', optimal conditions for protoplast transformation system of Bacillus sp.YBL-7 by the vector plasmid pE194 were investigated. The protoplasts of Bacillus sp. YBL-7 were obtained at best efficiency by treatment with 200${\mu}g$/ml of lysozyme in the pH 7.0 of SMM buffer for 90 minutes at $40^{\circ}C$. The cell wall of the protoplast was regenerated on the agar plate containing 1.2% agar and 0.7 M mannitol. Under the best condition for protoplast formation and regeneration, the optimal transformation was achieved with 40% polyethylene glycol (M.W. 4000) treatment for 10minutes. The vector plasmid pE194 showed the best transformation frequency at 5$\mu$g/ml of final concentration. The pE194 was very stable over 80% in the transformants.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.41-45
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• 2002

An efficient and reproducible procedure for the large scale propagation of Hovenia dulcis Thunb. is described. Shoot primodia emerging from the leaf surface was induced from MS medium supplemented with NAA. Stem cuttings were suitable explants for multiple shoot proliferation. They produced axillary shoots which branched repeatedly, yielding an average of 7 shoots per explants after 4 weeks in culture, when cultured on a woody plant medium (WPM) containing 0.1mg/l BA and 0.1mg/l NAA. Stem, leaf and root segments from axenic seedlings were used as explant source to induce somatic embryogenesis. A high frequency of somatic embryos were induced directly from leaf in MS medium with NAA, 2,4-D and in medium containing NAA, 2,4-D with BA. Somatic embryos were germinated in MS medium supplemented with 1mg/ l $GA_3$. Somatic embryos proliferated secondary somatic embryos rapidly after transfer to MS medium supplemented with 1mg/ l kinetin, 1mg/ l $GA_3$ and 2% dextrose.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.12-19
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• 1999

To improve biopolymer productivity and properties of Bacillus strains, protoplast fusion was performed between biopolymer producing Bacillus subtilis K-1 and lactose utilizing Bacillus coagulans. The results were as follows; Protoplasts mixed in fusion fluid containing 33% PEG 6000, 1% PVP and 10 mM $CaCl_2$ were reacted for 5 min at $37^{\circ}C$ and then centrifused protoplasts were directly overlaid on the selective media containing $100\;{\mu}g/ml$ antibiotics and incubated for 3 days. At this conditions, the frequency of protoplast fusion was generally in the range of $4.6{\times}10^{-5}\;to\;1.8{\times}10^{-7}$ in ratio. Segregation ratio was observed between 1 to 6% indicating genetic stability of all the fusants. Fusants growth were also observed on the media contained amino acid and antibiotics as required marked materials. DNA contents of the selected fusants were 1.6 to 2.7 times more than that of parent strains. With observation by TEM microscopy, spherical protoplasts were first released from the swollen parental cells and then contracted to fuse in the process of fusion. And fused cells were observed representative vesicle. Originally, the parental cells were observed as in the morphology of thick-walled and double membrane-surrounded rod shape with TEM microscopy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.617-623
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• 2001

To predict the seasonal variation of dissolved oxygen (DO) in Hakata bay, Japan, possible 20 time-series of different hourly-solar-radiation intensities were generated based on stochastically changing solar radiation intensity, and a numerical simulation on dissolved oxygen (DO) was carried out for each time series by using the Sediment-Water Ecological Model (SWEM). The model, consisting of two sub-models with hydrodynamic and biological models, simulates the circulation process of nutrient between water column and sediment, such as nutrient regeneration from sediments as well as ecological structures on the growth of phytoplankton and zooplankton, The results of the model calibration followed the seasonal variation of observed water quality well, and generated cumulative-frequency-distribution (CFD) curves of daily solar radiation agreed well with observed ones, The simulation results indicated that the exchange of sea water would have a great influence on the DO concentration, and that the concentration could change more than 1 mg/L in a day. This prediction method seems to be an effective way to examine a solution to minimize fishery damage when DO is depleted.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.32-38
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• 2018

Purpose: The purpose of present study was to retrospectively analyze the survival rate of narrow diameter implant less than 3.6 mm by initial stability and radiographic measurements. Materials and Methods: In total, 24 patients who received 38 narrow diameter implants (${\leq}3.6mm$ in diameter, ${\geq}7mm$ in length) were enrolled in this retrospective study. The cumulative survival rate was calculated and various factors were investigated according to the implant platform diameter, body diameter, length, position, concomitant use of guided bone regeneration in implant placement and final prosthesis type. Initial stability was investigated with implant stability quotient (ISQ) value. The mesial and distal marginal bone level (MBL) change was calculated with radiography. Results: The overall survival rate was 92.11%. Mean ISQ value and MBL change of survival implants was 66.26 and $0.14{\pm}0.31mm$, respectively. None of the implants with platform diameters larger than the body diameter failed. Conclusion: In conclusion, the findings of present study suggest that narrow diameter implant could be predictable treatment in narrow alveolar ridge.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.44-45
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• 2010

We are currently conducting studies on culturing and biocompatibility assessment of various cells such as neural stem cells and induced pluripotent stem cells(IPS cells) on carbon nanotube (CNT), on nerve regeneration electrodes, and on silicon wafers with a focus on developing nerve integrated CNT based bio devices for interfacing with living organisms, in order to develop brain-machine interfaces (BMI). In addition, we are carried out the chemical modification of carbon nanotube (mainly SWCNTs)-based bio-nanosensors by the plasma ion irradiation (plasma activation) method, and provide a characteristic evaluation of a bio-nanosensor using bovine serum albumin (BSA)/anti-BSA binding and oligonucleotide hybridization. On the other hand, the researches in the case of "novel plasma" have been widely conducted in the fields of chemistry, solid physics, and nanomaterial science. From the above-mentioned background, we are conducting basic experiments on direct irradiation of body tissues and cells using a micro-spot atmospheric pressure plasma source. The device is a coaxial structure having a tungsten wire installed inside a glass capillary, and a grounded ring electrode wrapped on the outside. The conditions of plasma generation are as follows: applied voltage: 5-9 kV, frequency: 1-3 kHz, helium (He) gas flow: 1-1.5 L/min, and plasma irradiation time: 1-300 sec. The experiment was conducted by preparing a culture medium containing mouse fibroblasts (NIH3T3) on a culture dish. A culture dish irradiated with plasma was introduced into a $CO_2$-incubator. The small animals used in the experiment involving plasma irradiation into living tissue were rat, rabbit, and pick and are deeply anesthetized with the gas anesthesia. According to the dependency of cell numbers against the plasma irradiation time, when only He gas was flowed, the growth of cells was inhibited as the floatation of cells caused by gas agitation inside the culture was promoted. On the other hand, there was no floatation of cells and healthy growth was observed when plasma was irradiated. Furthermore, in an experiment testing the effects of plasma irradiation on rats that were artificially given burn wounds, no evidence of electric shock injuries was found in the irradiated areas. In fact, the observed evidence of healing and improvements of the burn wounds suggested the presence of healing effects due to the growth factors in the tissues. Therefore, it appears that the interaction due to ion/radicalcollisions causes a substantial effect on the proliferation of growth factors such as epidermal growth factor (EGF), nerve growth factor (NGF), and transforming growth factor (TGF) that are present in the cells.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.7
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• pp.707-722
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• 2019

The concept of neighborhood parks has been used as the principle of forming a community in our society going through modern and contemporary times. The concept of neighborhood parks equipped with physical facilities has been discussed constantly regarding the roles and meanings of them. This study focuses on pocket parks which have been playing roles in improving environment through regeneration and forming regional communities based on that as neighborhood facilities. This author carried out field investigation on total 72 Hanpyeong Park and Hanpyeom Parks formed in the capital area and examined the significance of planning them and also their utility and residents and users' attachment to them through a survey. In this process, this researcher has been able to draw following conclusions. First, according to the demographic characteristics of users, there is significant difference found by groups in terms of their place attachment to the parks. This implies that difference in the major types of residences supplied these days influences their intention to experience ecological space. Second, according to their educational background, there is significant difference found by groups regarding their place attachment to the parks. Third, according to user behavior, there are differences found in their place attachment to the parks and also detailed differences found by groups in terms of the frequency of use and duration of stay.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.38-48
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• 2019

Background: Interspecific ginseng hybrid, Panax ginseng ${\times}$ Panax quenquifolius (Pgq) has vigorous growth and produces larger roots than its parents. However, F1 progenies are complete male sterile. Plant tissue culture technology can circumvent the issue and propagate the hybrid. Methods: Murashige and Skoog (MS) medium with different concentrations (0, 2, 4, and 6 mg/L) of 2,4-dichlorophenoxyacetic acid (2,4-D) was used for callus induction and somatic embryogenesis (SE). The embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 Schenk and Hildebrandt (SH) medium. The developed taproots with dormant buds were treated with $GA_3$ to break the bud dormancy, and transferred to soil. Hybrid Pgq plants were verified by random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analyses and by LC-IT-TOF-MS. Results: We conducted a comparative study of somatic embryogenesis (SE) in Pgq and its parents, and attempted to establish the soil transfer of in vitro propagated Pgq tap roots. The Pgq explants showed higher rate of embryogenesis (~56% at 2 mg/L 2,4-D concentration) as well as higher number of embryos per explants (~7 at the same 2,4-D concentration) compared to its either parents. The germinated embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 SH medium to support the continued growth and kept until nutrient depletion induced senescence (NuDIS) of leaf defoliation occurred (4 months). By that time, thickened tap roots with well-developed lateral roots and dormant buds were obtained. All Pgq tap roots pretreated with 20 mg/L $GA_3$ for at least a week produced new shoots after soil transfer. We selected the discriminatory RAPD and ISSR markers to find the interspecific ginseng hybrid among its parents. The $F_1$ hybrid (Pgq) contained species specific 2 ginsenosides (ginsenoside Rf in P. ginseng and pseudoginsenosides $F_{11}$ in P. quinquefolius), and higher amount of other ginsenosides than its parents. Conclusion: Micropropagation of interspecific hybrid ginseng can give an opportunity for continuous production of plants.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.449-454
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• 2011

This experiment was conducted to evaluate growth rate among 15 embryogenic tissue lines (ETLs), comparison of maturation on somatic embryos (SEs) with 13 ETLs and efficiency with various concentrations of gelrite on SEs germination in Japanese red pine (Pinus densiflora). In comparison of ETLs growth rate (folds) with 15 lines, the 05-4 line (5.3 folds) showed the highest rate, on the other hand, the lowest one was recorded in the line of 05-37 (1.4 folds). The 13 ETLs were tested for the extent of SEs production. The best production was recorded in the line of 05-4 (39.8/90 mg F.W.). However, most of ETLs, except 5 lines (05-4, 12, 21, 29 and 37), did not produce SEs at all, therefore, big differences in the ability of SEs production existed among the ETLs tested. Effects of various gelrite concentrations for SEs germination with 3 ETLs were also compared. The highest result was obtained from 0.2% gelrite concentration with 05-4 line (47.3%), there was a inclination that the rate of germination was gradually declined over 0.2% gelrite concentration with the 05-4 and 29 lines. respectively. In contrast, in the line of 05-37, no SEs germination occurred on medium with 0.1 or 0.2% gelrite. In conclusion, the growth rate, SEs production and germination frequency were appeared to deeply depended on the ETLs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.425-430
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• 1983

Rice (Oryza sativa L.) anthers collected from different genotypes were cultured to investigate the priority to increase callus production rate among several factors affecting on callus formation. Rice varieties, F$_1$ hybrids and F$_2$ plants differed greatly in their abilities to produce callus from anthers, and it was confirmed that the culturability of rice anther was a heritable characteristic. Cold shock treatment before plating anthers promoted callus formation rate, but combined effect with genotype having high culturability was more significant. The response to sucrose concentration in culture medium in callus induction rate was different between rice genotypes, but combined effect with genotype was not significant. Single supplement of NAA to R$_2$ medium increased callus production rate remarkably only in rice genotype having high culturability. Conclusively selection of genotypes is most important to increase callus initiation frequency from rice anthers.