• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.238-243
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• 1996

Three half-sib families of Betula platyphylla var. japonica had been introduced from Japan and tested for their growth potentiality by comparing with control trees originating from previously introduced and cultivated stands of unknown seed origin. Two of the three introduced family groups from Japan showed superior tree growth in both diameter and height to control one up to the age of four. But only one family group remained superior to the control trees at age six. It appeared from the results that Betula platyphylla var. japonica families, introduced from Japan, can be directly used for the production of planting stocks for commercial planting and/or as parental trees for the production of intra- and interspecific hybrids.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.431-437
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• 2016

This study was carried out to investigate pests and their damage caused to commercial greenhouse strawberries in Jeju from 2013 to 2016. A total of 8 orders, including 31 species, of pests were found. Among them, the major pests were Tetranychus urticae, Frankliniella occidentalis, and Aphis gossypii. Although Trialeurodes packardi and Empoasca vitis were sometimes severely damaged strawberries, their frequency of occurrence and damage caused increased gradually. Of lepidopteran pests, Spodoptera litura showed the highest occurrence and damage. Although Helicoverpa armigera was showed a low occurrence frequency, it caused severe damage. We discussed the seasonal occurrence patterns of four pests-F. occidentalis, the alate A. gossypii, T. packardi and E. vitis-monitored by yellow-colored sticky traps.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.557-566
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• 1996

It is known that some natural extracts from plants have a various range of antimicrobial and antiinflammatory activity. There are lots of clinical trials to develop toothpastes containing natural extracts for prevention of dental caries and gingival inflammation. The purpose of this study was to evaluate antimicrobial and antiinflammatory activity of magnolol containing toothpastes and other commercial toothpastes. Eleven kinds oftoothpastes were used. They include magnolol, sanguinarine, Myrrha, Mori radicis cortex,Cimicifugae rhizoma, sodium fluoride, aminocaprolactic acid etc. Six strains of bacteria were used for this test, ego Porphylomonas gingivalis, Prevotellain-termedia, Actinobacillus actinomy cetemcomitans, Streptococcus mutans, Stretococcus sanguis, and Actinomyces species. Antimicrobial activity was determined by an agar dillution method and a broth microdillution method. Antiinflammatory activity was assessed by the inhibition of $PGE_2$ production from gingival fibroblast with the addition of rHIL-1 and centrifuged solution of toothpastes. Control group was only rHIL-1 additive sample. $PGE_2$ enzyme immunoassay systemfAmersham, In. Buckinghamshire, U.K). $PGE_2$ level was measured by ELISA reader with 450 nm, The results from the study revealed that toothpastes containing natural extracts generally had high antimicrobial and antiinflammatory activity. Especially magnolol containing toothpaste showed higher antimicrobial activity than other toothpastes, and sanguinarine containing toothpaste showed particularly high antimicrobial activity in A. actinomicetemcomitans and A. viscosus. In some degree all toothpastes inhibited $PGE_2$ production, but magnolol containing toothpaste was potent inhibitor of $PGE_2$. Sodium chloride containing toothpaste had also effective result. The results suggested that toothpastes containing natural extracts were promising in plaque control and prevention of dental caries and gingivitis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.885-891
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• 1996

Various problems in fermented fish products have been a major obstacle to manufacture the product in large scale, which is mainly concerned with the food safety. In this review, salt-fermented anchovy was selected to elucidate the characteristics of microorganisms involved in fermentation; thereby, it is suggested for research areas to achieve the quality improvement of tile product. Different microorganisms were involved in fermentation of anchovy. Dominant species were reported to be Bacillus sp., Pseudomonas sp., and Micrococcus sp., other microorganisms were Vibro sp., Clostridim sp., Serratia sp., Achromobacter sp., Streptococcus sp., Breuibacterium sp., Halobacterium sp., Flavobacterium sp., Corynebacterium sp., Acinetobacter sp., Sarcina sp., Staphylococcus sp., Torulopsis sp., and Saccharomyces sp. To standardize the quality of fermented fish products, screening and isolation of promising microorganisms should be carried out to develop different types of products; at the same time, proper sanitation control should be employed to keep the commercial value of the product by prolonging the shelf life.

• 대한생식의학회:학술대회논문집
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• 2000.06a
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• pp.13-28
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• 2000

Human spermatozoa exhibit a capacity to generate ROS and initiate peroxidation of the unsaturated fatty acids in the sperm plasma membrane, which plays a key role in the etiology of male infertility. The short half-life and limited diffusion of these molecules is consistent with their physiologic role in key biological events such as acrosome reaction and hyperactivation. The intrinsic reactivity of these metabolites in peroxidative damage induced by ROS, particularly $H_2O_2$ and the superoxide anion, has been proposed as a major cause of defective sperm function in cases of male infertility. The number of antioxidants known to attack different stages of peroxidative damage is growing, and it will be of interest to compare alpha-tocopherol and ascorbic acid with these for their therapeutic potential in vitro and in vivo. Both spermatozoa and leukocytes generate ROS, although leukocytes produce much higher levels. The clinical significance of leukocyte presence in semen is controversial. Seminal plasma confers some protection against ROS damage because it contains enzymes that scavenge ROS, such as catalase and superoxide dismutase. A variety of defense mechanisms comprising a number of antioxidants can be employed to reduce or overcome oxidative stress caused by excessive ROS. Determination of male infertility etiology is important, as it will help us develop effective therapies to overcome excessive ROS generation. ROS can have both beneficial and detrimental effects on the spermatozoa and the balancing between the amounts of ROS produced and the amounts scavenged at any moment will determine whether a given sperm function will be promoted or jeopardized. Accurate assessment of ROS levels and, subsequently, OS is Vital, as this will help clinicians both elucidate the fertility status and identify the subgroups of patients that respond or do not respond to these therapeutic strategies. The overt commercial claims of antioxidant benefits and supplements for fertility purposes must be cautiously looked into, until proper multicentered clinical trials are studied. From the current data it appears that no Single adjuvant will be able to enhance the fertilizing capacity of sperm in infertile men, and a combination of the possible strategies that are not toxic at the dosage used would be a feasible approach.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1591-1596
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• 2006

Acaricidal effects of materials derived from Caesalpinia sappan heartwoods against Dermatophagoides farinae and D. pteronyssinus were assessed and compared with those evidenced by commercial benzyl benzoate and DEET. The observed responses varied according to dosage and mite species. The $LD_{50}$ values of the methanol extracts derived from C. sappan heartwoods were 6.13 and $5.44{\mu}g/cm^3$ against D. farinae and D. pteronyssinus, respectively. Furthermore, the ethyl acetate fraction derived from the methanol extract was approximately 8.71 more toxic than DEET against D. farinae, and 4.73 times more toxic against D. pteronyssinus. The biologically active constituent from the ethyl acetate fraction of C. sappan heartwood extract was purified via silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by $GC-MS,\;^1H-NMR,\;^{13}C-NMR,\;^1H-^{13}C\;COSY-NMR$, and DEPT-NMR spectroscopy, and identified as juglone (5-hydroxy-l,4-naphthoquinone). Based on the $LD_{50}$ values of juglone and its derivatives, the most toxic compound against D. farinae was juglone ($0.076{\mu}g/cm^3$), followed by benzyl benzoate ($9.143{\mu}g/cm^3$) and 2methyl-l,4-naphthoquinone ($40.0{\mu}g/cm^3$). These results indicate that the acaricidal activity of C. sappan heartwoods is likely to be the result of the effects of juglone. Additionally, juglone treatment was shown to effect a change in the color of the cuticles of house dust mites, from colorless-transparent to dark brownish-black. Accordingly, as a naturally occurring acaricidal agent, C. sappan heartwood-derived juglone should prove to be quite 'useful as a potential control agent, lead compound, and house dust mite indicator.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.77-85
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• 2006

Entomopathogenic nematodes (EPNs) have been used as biological control agents for control of various agro-forest insect pests, and are especially effective against soil-dwelling insect pests. Effect of soil moisture on pathogenicity of commercial EPNs for white grub control was evaluated in laboratory, pots, and golf courses. Pathogenicity of EPNs in sand column was variable depending on depth, soil moisture, and EPN species or strain. All tested EPNs (Heterorhabditis sp. GSNUH1, Heterorhabditis sp. GSNUH2, Steinernema carpocapsae GSN1, and S. longicaudum Nonsan strain) showed similar pathogenicity against the bait insect, great wax moth (Galleria mellonella) larva at 2 cm deep at a given soil moisture. However, pathogenicity of the Heterorhabditis sp. GSNUH1 strain was decreased with increasing soil moisture. Pathogenicity of S. carpocapsae GSN1 strain was the lowest in 3% soil moisture (v/w) at 7 cm depth. However, there was no difference in pathogenicity between Heterorhabditis sp. GSNUH2 and S. longicaudum Nonsan strain. Although pathogenicity of Heterorhabditis sp. KCTC 0991BP strain showed no difference against the 2nd instar of Exomala orientalis, that of the S. carpocapsae GSN1 strain was decreased in the laboratory depending on soil moisture. Highly pathogenic strain EPN, Heterorhabditis sp. KCTC 0991BP strain, showed higher pathogenicity at 100 mm irrigation than non-irrigation or 10 mm irrigation. However, poor pathogenic strain EPN, S. carpocapsae GSN1 strain, was not different in pathogenicity from the 2nd instar of Exomala orientalis in creeping bentgrass (Agrostis palustris) depending on irrigation amount in the pot. Pathogenicity of EPNs in field experiment at the tee of Ulsan golf club showed a similar trend to that in the pot experiment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.696-701
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• 2002

Optimal conditions for preparing of chitooligosaccharides from chitosan with cellulase was researched by response surface methodo-logy, Penicillium funiculosum derived cellulase was most effective for chitooligosaccharides production as the point of hydrolyzing activity and commercial utility. The result which measures the change of degrading ratio at time course, 10 hr reaction showed a exponential increase and after that time degrading ratio was not changed. The optimal conditions determined by response surface methodology with central composite design of total 26 species were $0.5\%$ of chitosan, 143 U enzyme, 49$^{\circ}C$ of reaction temperature, 13.2 hr of reaction time and pH 3.8. Major chitooligosaccharides produced from chitiosan on optimal conditions were dimer and trimer.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.441-445
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• 2015

Carrot (Dacus carota var. sativus) is one of the top-ten most economically important vegetable crops produced worldwide, and the root-knot nematodes, Meloidogyne spp., are one of the most important pests in the carrot. In Korea, M. hapla and M. incognita are presumed to be the major root-knot nematodes distributing mostly in open carrot fields and greenhouses, respectively. In our study, currently-developed and commercial carrot cultivars and the parental lines were examined for their pathological responses to M. incognita and M. hapla 7 weeks after inoculation with about 1,000 second-stage juveniles (J2) of the nematodes. All the carrot cultivars and lines showed susceptible responses to both nematodes with the gall index (GI) of 2.4-4.4, which were always higher on the carrot plants infected with M. incognita than M. hapla. Gall sizes were remarkably larger with more serious reduction of the root growths in the plants infected with M. incognita than M. hapla, suggesting the carrot lines examined in our study were more susceptible to the former than the latter. In the infection sites of the root tissues, giant cells were more extensively formed, occupying larger stellar regions with the prominent destruction of adjacent xylem vessels by M. incognita than M. hapla. All of these results suggest M. incognita affect more seriously on the carrot plants that are grown in greenhouses, compared to M. hapla that has a major distribution in open carrot fields, which would be used for determining cropping systems based on target nematode species, their damage and pathological characteristics.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.