• Journal of Ginseng Research
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• v.40 no.2
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• pp.97-104
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• 2016

Background: Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. This study aimed to screen antagonistic bacteria and develop a biocontrol system for root rot complex of Panax notoginseng. Methods: Pure-culture methods were used to isolate bacteria from the rhizosphere soil of notoginseng plants. The identification of isolates was based on the analysis of 16S ribosomal RNA (rRNA) sequences. Results: A total of 279 bacteria were obtained from rhizosphere soils of healthy and root-rot notoginseng plants, and uncultivated soil. Among all the isolates, 88 showed antagonistic activity to at least one of three phytopathogenic fungi, Fusarium oxysporum, Fusarium solani, and Phoma herbarum mainly causing root rot disease of P. notoginseng. Based on the 16S rRNA sequencing, the antagonistic bacteria were characterized into four clusters, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetesi. The genus Bacillus was the most frequently isolated, and Bacillus siamensis (Hs02), Bacillus atrophaeus (Hs09) showed strong antagonistic activity to the three pathogens. The distribution pattern differed in soil types, genera Achromobacter, Acidovorax, Brevibacterium, Brevundimonas, Flavimonas, and Streptomyces were only found in rhizosphere of healthy plants, while Delftia, Leclercia, Brevibacillus, Microbacterium, Pantoea, Rhizobium, and Stenotrophomonas only exist in soil of diseased plant, and Acinetobacter only exist in uncultivated soil. Conclusion: The results suggest that diverse bacteria exist in the P. notoginseng rhizosphere soil, with differences in community in the same field, and antagonistic isolates may be good potential biological control agent for the notoginseng root-rot diseases caused by F. oxysporum, Fusarium solani, and Panax herbarum.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.353-360
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• 2017

Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

• Conservation Science in Museum
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• v.21
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• pp.29-40
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• 2019

An experimental study was conducted to test the applicability of natural hydraulic lime (NHL) as a reinforcing agent for the supporting layers of mural paintings in ancient tombs.Drawing upon preceding studies on mural paintings inancient tombs, samples of reinforcing agents for various conditions were prepared using NHL products, and pseudo-samples of the supporting layers of mural paintings were also produced. The samples were cured for 7, 28, and 84 days in a high-humidity condition similar to that of the mural-tomb environment. Physical properties such as dimensional stability and compressive strength were measured for each curing period.The results indicated that the NHL samples had a rapid curing speed and a low contraction ratio and are therefore suitable as reinforcing agents, whereas they showed a poor match in terms of strength compared to the supporting layer,and also low whiteness. The dimensional stability and compressive strength testsrevealedthat an NHL product mixed with a pseudo-sample of a supporting layer provided desirable conditions for reinforcing agent. The findings suggested that different conditions for curing time and strength should be considered for each supporting layer prior to applying NHL as a reinforcing agent for damaged mural paintings in ancient tombs.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.224-234
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• 2018

An efficient method to select drought tolerant Korean native plants using in vitro culture system was established in this study. While the plant growths and root inductions of each plant were proportionately affected by concentrations of mannitol on in vitro culturing seven plant species to test tolerance to osmotic stress, growth index (GI) and number of root induction of Chrysanthemi zawadskii var. latilobum and Dianthus chinensis var. semperflorens plantlets were higher than the others in 125mM mannitol. In test with polyethylene glycol (PEG), plantlets of C. zawadskii var. latilobum and D. chinensis var. semperflorens showed higher GI and number of root induction than the others in 33.3mM. On testing whether the well grown plants under osmotic stress are tolerant to virtual drought stress, there were significant differences in the withering rates of C. zawadskii var. latilobum and D. chinensis and those of were Aster yomena and Centaurea cyanus after 12 days without watering. It was found that significantly lower stomata numbers were shown in both drought tolerant plants than the sensitive plants. Averages of the stomata circumferences and the stomata area in the plantlets of the tolerant species were larger than those of the sensitive plants D. chinensis var. semperflorens showed the lowest transpiration level per unit area. The highest stomatal area per unit area was found in C. zawadskii, followed by D. chinensis var. semperflorens, Aster yomena and C. cyanus. In conclusion, C. zawadskii var. latilobum and D. chinensis var. semperflorens were more tolerant to drought than other two species. Furthermore in vitro selection was successfully used to screen drought tolerance species of native plant species.

• Journal of the Korean Graphic Arts Communication Society
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• v.28 no.2
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• pp.1-11
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• 2010

The physicochemical characteristics, adhesion power, and conservation of imported tapes repairing documents that consisted of adhesive, carrier, and masking were investigated. Materials related to pressure sensitive adhesive produced in domestic companies were examined also. And then, the performance evaluation of prototype manufactured in our laboratory was undertaken. Both the pressure sensitive tapes were compared. The polyacrylate of adhesive agents such as polyacrylate, starch, Glue, and PVA of imported tapes was best. The adhesion strength, power, reversibility, and stability (deterioration) of imported tapes were analyzed. By comparing results of imported tapes, two adhesive agents were selected finally. The carriers of imported tapes are made of one of papers, cotton sheets, and felts. Major carrier material was a paper. The jutes, conifers, and hardwoods were main ingredient of papers. The durability of Hangi($18{\pm}2g/m^2$) was one and half times superior to imported one.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.192-196
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• 2005

The SNF2/SW12 family comprises proteins from a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. This study was shown the characterization of hrp2+ gene which was isolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of hrp2+ gene showed striking evolutionary conservation among the SNF2 family of proteins. The transcript of hrp2+ gene was found to be a 4.7 kb as identified by Northern hybridization. To investigate the inducibility of hrp2+ gene, transcript levels were examined after treating the cells to various DNA damaging agents. The transcripts of hrp2+ were induced by UV-irradiation. But the transcripts were not induced by treatment of $ 0.25\%$ Methylmethane sulfonate (MMS). These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of this gene. Hrp2 protein was purified near homogeneity by combination of affinity chromatography. We tested the purified Hrp2 protein for the helicase activity in an oligonucleotide release assay. However we were unable to detect any helicase activity associated with the Hrp2 protein, indicating that the helicase motifs in Hrp2 are merely indicators of a broader DNA-dependent ATPase activity.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.371-383
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• 1999

This paper discusses the importance of indoor air quality based on literaure review of domestic and foreign studies. A number of international efforts to propose standards and guidelines for indoor environmental quality are also reviewed. The pattern of major studies on indoor air quality focussed on characterizaton of gaseous pollutants, particulates, and other specific pollutants during the past decades, whereas VOCs, specific carcinogen, and microbiological agents might be good target pollutants to investigate the effects of human health in recent years. Management of indoor air quality requires a different approach than that adopted for outdoor air. Adequate ventilation of the indoor environment is essential, and a balance between energy conservation and the need for good air quality is required. The ways for managing indoor air quality that will be of great importance are discussed a role of control policy for guidance on how to achieve good indoor air quality.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.108-115
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• 2012

Archaeological waterlogged woods found under the sea, in lakes, or in swamp environments are generally weak and fragile. If waterlogged wood materials were taken out of the water and left without modification, they would collapse and lose their original dimensions completely. Conservation is performed to replace the water with chemical agents and to give dimensional stabilization and durability. EDTA and PEG are the most commonly used in the preservation of wood. pH control-precipitation method is used for recovery of EDTA from waste fluid of archeological waterlogged wood conservation treatment. The black substance is eliminated from wood as Fe-EDTA complex are formed and EDTA is separated and precipitated from Fe-EDTA complexes at pH 2.68 or less. The result of analysis of the precipitated products and the commercial EDTA by FT-IR and FE-SEM showed that precipitated product by pH adjusted was not a type of Fe-EDTA complex, but pure EDTA. Waste fluid produced in PEG treatment shows the black color and has an offensive odor by organic matter extracted from wood. Color of waste fluid is decolored with oxidation reaction by peroxy hydrate. In FT-IR and SEM-EDX of PEG after freeze-drying process, no significant change of functional groups induced from oxidation is observed, and any metal ion does not exist in the solid PEG specimen. The molecular weight of PEG is measured using GPC and viscometry. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Consequently, the peroxidation with $H_2O_2$ is a reasonable and simple method to decolor the used PEG solution.

• Journal of Conservation Science
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• v.27 no.3
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• pp.243-250
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• 2011

Seven glass beads from Bupwha-ri site, Yeongdong dated Joseon dynasty were analyzed with SEM/EDS and X-ray diffraction methods. Six samples were classified to potash glass system($K_2O-CaO-SiO_2$) with HCA(High CaO and $Al_2O_3$) and high concentration of MgO suggested raw materials to plant ashes. Especially one sample from tomb no. 8 was highly different concentration of $K_2O$ and MgO with others. It was shown that they were different sources of raw materials. Mostly coloring agents of potash glasses were owing to Fe and Cu. One sample was found to lead glass system(PbO-$SiO_2$) with 12% PbO. The content of PbO was differentiated with other lead glasses since we analyzed so far. It needs more study for compositions of lead glasses with regions and ages.

• Journal of Conservation Science
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• v.27 no.4
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• pp.345-356
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• 2011

To remove metal stains of the ceramics, chemical cleaning is essential case by case. This study investigated the removal characteristics of iron stains by oxalic acid and citric acid including their application methods of soaking and poultice. The soaking method in cleaning agents showed removal process by color difference and released iron contents from iron stains on ceramics. Iron stains were removed successfully from ceramics, which soaked in oxalic acid for 60 hours. However, it is recommendable to soak in 0.25M oxalic acid for one to three hours because most iron stains were disappeared in 3 hours soaking. Citric acid is less effective than oxalic acid in removing iron stains because of heavy molecular weight and low acidity. Poultices (bentonite, sepiolite, activated carbon fiber and celite) with oxalic acid were applied on contaminated ceramics. After ten hours, iron stains on ceramics were removed successfully by poultice. Among them, bentonite and sepiolite have better application. Therefore, sepiolite with 0.25M oxalic acid was applied on the iron stains of whiteware and celadon from Ma Island, and then stains were removed. However, it is judged that the application methods can be varied according to the form and depth of contaminant. In addition, the residues of poultice on the ceramics will be considered for preventing contamination.