• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.61-66
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• 2010

Purpose: Recently, Department of Nuclear Medicine have an interest in Video Display Terminals (VDT) syndrome including musculoskeletal disorders, ophthalmologic disorders, trouble of electromagnetic waves and stress disorders occur to VDT workers as the growing number of users and rapid pace of service period supply in large amount. This study research on the actual condition for VDT syndrome in Nuclear Medicine, Seoul National University Hospital (SNUH), discover the problem and draw a plan of upcoming improvement. The aim of this study establish awareness about VDT syndrome and is to prevent for it in the long run. Materials and Methods: Department of Nuclear Medicine, SNUH is composed Principle part, Pediatric part and PET center. We estimated risk factors visit in each part directly. Estimation method use "Check list for VDT work" of Wonjin working environment health laboratory and check list is condition of VDT work, condition of work tables, condition of chairs, condition of keyboards, condition of monitors, working position, character of health management and other working environment. Analysis result is verified in Department of Occupational and Environment, Hallym University Sacred Heard Hospital. Results: As a result of analysis, VDT condition of Department of Nuclear Medicine, SNUH is rule good. In case of work tables, recent of things are suitable to users upon the ergonomical planning, but 15% of existing work tables are below the standard value. In case of chairs are suitable, but 5% of theirs lost optimum capacity become superannuated. The keyboards are suitable for 98% of standard value. In case of monitors, angle control of screen is possible of all, but positioning control is impossible for 38%. In case of working position, 10% is fixed positioning for long time and some of the items researched unsuitable things for standard. At health management point, needed capable of improvement. Also, other working condition as lighting, temperature, noise and ventilation, discovered the problem, but is sufficient to advice value. Conclusion: VDT syndrome is occurrences of possibility continuously, come economical expensive about improvement, is inherent in various causes and originate without your knowledge. So, there is need systematic management system. In Nuclear Medicine, VDT syndrome make it better that constant interest and effort as improvement of ergonomical working environment, improvement of working procedure, regular exercise and steady stretching, and can be prevented fairly. This promote physical and mental condition of worker in top form in comfortable working environment, so this is judged by enlargement of operations efficiency and rising of satisfaction ratings of the inside client.

• Journal of Aquaculture
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• v.3 no.1
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• pp.49-63
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• 1990

A population ecological study was carried out to estimate survival and growth rates, biomass, biological production and turnover ratio of cultured sea squirt, Halocynthia roretzi, by growth stages, using data from in situ culture experiment off Hansando in the southern part of Korea from February 1985 to July 1986. The squirt population followed an exponential decay function and the instantaneous coefficient of total mortality (Z) was estimated to be 0.0614 $month^{-1}$(Var (Z) = 0.000126). Growths in total weight and meat weight of squirts were expressed as linear functions during the period of culture experiment. The growth of squirts showed a negative correlation with the water temperature. The mean biomass per string ranged from 2.14 kg for March of the first year to 16.26 kg for March of the next year. The biological production per string was estimated to range from 3.28 kg for the first summer (June - July) to 6.46kg for the first late winter (February-March). The peak of turnover ratio occurred in the late winter (February-March) as 3.013 and the ratios sharply declined thereafter. Based on the results of this study, management implications for culturing sea squirts were also suggested. The optimum harvest time ($t_{mb}$) when the peak biomass in terms of total weight occurred was estimated to be late June of the second year, which corresponded to 16.7 months after the main hanging. However, the time when the peak biomass in terms of meat weight was occurred was early July of the second year. The maximum harvest biomass was 17.4 kg per string in terms of total weight and 6.3 kg per string in terms of meat weight. In conclusion, the process of culture should be conducted on the basis of the knowledge of population ecological theories as shown in this study.

• Journal of Mushroom
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• v.15 no.3
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• pp.129-133
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• 2017

Oyster mushroom is a type of mushroom that is commonly cultivated and consumed in Korea. P. ostreatus 'Suhan' is a preferred cultivar for many mushroom farmers because it has a dark pileus and thick stipe. However, as it is very sensitive to environmental conditions, farmers consistently demand an alternative cultivar. To develop a new cultivar, the parental strains KMCC01680 ('Suhan') and KMCC00478 ('Gosol') were selected from various collected P. ostreatus strains by cultivating genetic resources. P. ostreatus 'Heuksol' was developed by the method of Mon-Mon crossing between monokaryotic strains derived from 'Suhan' and 'Gosol'. Thirty strains of 174 crossed strains were initially selected by cultivation experiments. After bulk cultivation tests, 'Heuksol' was selected. The nuclear DNA profile of 'Heuksol' was similar to those of the parental strains, 'Suhan' and 'Gosol', when RAPD (random amplified polymorphic DNA) primers and UPF (Universal PCR Fingerprinting) 2, 3, and 4 were used. The optimum temperature for mycelial growth was $30^{\circ}C$ for 'Heuksol', but medium-high temperatures were also appropriate, especially $13-20^{\circ}C$. The fruiting body production per bottle (1,100 mL) was approximately 140.8 g. When compared to the control strain 'Suhan', the thickness of the stipe of 'Heuksol' was greater than that of 'Suhan' (13.5 mm vs 9.4 mm). The pileus diameter of 'Heuksol' was similar to that of 'Suhan' and the pileus thickness of 'Heuksol' and 'Suhan' was 19.7 mm and 21.8 mm, respectively. 'Heuksol' had more a productive stipe number than 'Suhan' and the pileus of 'Heuksol' was dark gray, even at high temperatures. Therefore, it was suggested that this new cultivar, 'Heuksol', could provide an alternative to 'Suhan' and contribute to the profit of oyster mushroom farms.

• Journal of Mushroom
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• v.16 no.3
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• pp.203-207
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• 2018

'Daebak', a new cultivar of Grifola frondosa, was bred by mating two monokaryotic strains isolated from 'F14309' and 'GMGF44062' at the Mushroom Research Institute, Gyonggi-Do ARES in 2017. The optimum temperature for mycelial growth of 'Daebak' was $25^{\circ}C$ on PDA medium. In bottle cultivation, the culture period of 'Daebak' was 57 days, which was 2 days shorter than that of 'Cham' (control). The pinheading rate of 'Daebak' was 98.4%, which was 24.8% higher than that of 'Cham' and its CV (Coefficient of variation) was 0.6%, 5.3% lower than that of 'Cham'. Regarding the growth characteristics of 'Daebak', the diameter and thickness of the pileus were 27.7 mm and 1.73 mm, respectively, and the diameter and height of the fruiting bodies cluster were 132 mm and 87.2 mm, respectively. The pileus was thinner but the fruiting bodies cluster was larger than that of 'Cham'. Fruiting bodies weighed 139 g per 1,100 ml bottle of 'Daebak', which was 28% higher than that for 'Cham', with a CV of 2.5%, which was 6.2% lower than that of 'Cham'. The yield per 10,000 bottles (used for cultivation) of 'Daebak' was 1,376 kg, 70% higher than that of 'Cham', with a CV of 3.0% that was 11.5% lower than that of 'Cham'. With respect to physical characteristics, the strength and brittleness of the fruiting body of 'Daebak' was less than that of 'Cham'. When considering the period available for sale, the shelf life of 'Daebak' was 42 days, which was 6 days longer than that of 'Cham'.

• KSBB Journal
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• v.19 no.1
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• pp.50-56
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• 2004

The aim of this work was to investigate the purification and characterization dixoygenases isolated from Delftia sp. JK-2, which could utilize aniline, benzoate, and p-hydroxybenoate as sole carbon and energy source. Catechol 1,2-dioxygenase (C1, 2O), catechol 2,3-dioxygenase(C2, 3O), and protocatechuate 4,5-dioxygenase(4,5-PCD) were isolated by benzoate, aniline, and p-hydroxybenzoate. In initial experiments, several characteristics of C1 ,2O, C2, 3O, and 4,5-PCD separated with ammonium sulfate precipitation, DEAE-sepharose, and Q-sepharose were investigated. Specific activity of C1 ,2O, C2, 3O, and 4,5-PCD were approximately 3.3 unit/mg, 4.7 unit/mg, and 2.0 unit/mg. C1 ,2O and C2, 3O demonstrated their enzyme activities to other substrates, catechol and 4-methylcatechol. 4,5-PCD showed the specific activity to the only substrate, protocatechuate, but the substrates(e.g., catechol, 3-methylcatechol, 4-methylcatechol, 4-chlorocatechol, 4-nitrocatechol) did not show any specific activities in this work. The optimum temperature of C1, 2O, C2, 3O, and 4,5-PCD were 30$^{\circ}C$, and the optimal pHs were approximately 8, 8, and 7, respectively. Ag$\^$+/, Hg$\^$+/, Cu$\^$2+/ showed inhibitory effect on the activity of C1, 2O and C2, 3O, but Ag$\^$+/, Hg$\^$+/, Cu$\^$2+/, Fe$\^$3+/ showed inhibitory effect on the activity of 4,5-PCD. Molecular weight of the C1, 2O, C2, 3O, and 4,5-PCD were determined to approximately 60 kDa,35 kDa, and 62 kDa by SDS-PAGE.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.19-29
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• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Journal of Life Science
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• v.18 no.6
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• pp.789-795
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• 2008

To study the possible use of probiotics in fish farming, we evaluated antagonism of antibacterial strain Bacillus amyloliquefaciens H41 against the fish pathogenic bacterium Vibrio anguillarum NCMB1. The purification of growth inhibition factor produced by B. amyloliquefaciens H41 was achieved by obtaining supernatant of this bacterium. The growth inhibition factor was purified to homogeneity by 70% ammonium sulfate precipitation, DEAE-sephadex A-50 ion exchange chromatography, sephadex G-200 gel filtration column chromatography, and sephadex G-50 gel filtration column chromatography with 40.8 fold of purification and 2.9% yield. The molecular weight of the purified growth inhibition factor was 48 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH and temperature for the growth inhibition factor were pH 7.5 and $30^{\circ}C$, respectively. The activity of growth inhibition factor was enhanced slightly by some metal ions, such as $Mg^{+2}$, $Mn^{+2}$, but was inhibited by the addition of $Co^{+2}$, $Hg^{+2}$, $Zn^{+2}$ and $Ag^{+2}$. NaCl stability of the growth inhibition factor was observed with 50% residual activity at 3% NaCl concentration. Toxicity test showed that the purified B. amyloliquefaciens H41 growth inhibition factor did not affect the live of Japanese flounder (Paralichthys olivaceus) and the effectiveness was 78% of residual lethality compared to commercial antibacterial agents.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.70-75
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• 1986

The population and kinds of algae causing the waterbloom on the rice seedling bed and the damage of young rice plant by the nuisance green phytoplanktonic algae in rice field were studied to find out the efficiency of fertilizers and the effect of methods of fertilizers application in the rice field, laboratory, pot and green house. pot and green house. The results obtained were summarized as follows; 1. In the rice seedling bed, the kinds of algae causing waterblooms were identified mainly photosynthetic bluegreen algae as the Anabaena, Ulothrix and Oscillatoria spp. in reclaimed saline soil. Micromonospora, Oscillatoria, and Chlamydomonas spp. were habitated mainly in plain. Whereas, Spyrogyra, Oscillatoria and Navicula spp. were identified mainly in mauntainous area. 2. In the rice field, the nuisance phytoplanktonic green algae were identified mainly Scenedesmus, Chlamidospora, and Micromonospora spp. in Gimjae plain, in Namweon mountainous area and Gangjin costal plain, respectively. 3. The algal biomass has been havily habitated in which rice field were constituted with high pH value and high concentration of $NH^+_4-N$ and $NO^-_3-N$ in surface water and in soil with the optimum temperature for the algal growth ($22-30^{\circ}C$). 4. In the laboratory experiment, maximum algal biomass were obtained at levels of 80 ppm for the nitrogen and 20 ppm for the phosphorus. And were obtained of the levels of 40 ppm in the case of joint application of N and $P_2O_5$. 5. From the pot experiment, compare of the control plot, an addition of nitrogen alone or nitrogen+phosphorus enhanced algal biomass while the phosphorus alone did not. 6. Surface application of fertilizer was remarkably increased of algal biomass than did the whole layer or deep layer application.

• Journal of Mushroom
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• v.9 no.2
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• pp.59-62
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• 2011

To develop a new cultivar of King oyster mushroom(Pleurotus eryngii), G09-21 as parental strain was selected by the method of Di-mon crossing between monokaryotic strains derived from ASI 2824(Keunneutari No.2) and dikaryotic strain ASI 2887(Aeryni 3). The Pe21-51($G09-21-10{\times}2844-11$) was shown the best cultural characteristics, selected to be a new cultivar and named as 'Song-A'. The 'Song-A' was formed incompatibility line distinctly in the confrontation growth of parental strains Keunneutari No.2, Aeryni 3 and ASI 2844. The optimum temperature for mycelial growth, fruiting body development and pH arrange were $25{\sim}30^{\circ}C$, $14{\sim}16^{\circ}C$ and pH5~8, respectively. Fruiting body production per bottle was about $94.7{\pm}29.5$ g which is almost 106% quantity compared to that of other cultuvar Keunneutari No.2. And also the stip is thick and long but the number of available stipe is few. Analysis of the genetic characteristics of the new cultivar 'Song-A' showed a different DNA profile as that of the control strains, Keunneutari No.2, Aeryni 3 and ASI 2844, when RAPD(Random Amplified Polymorphic DNA) primers URP4 and 7 were used. This new cultivar 'Song-A' of Pleurotus eryngii is characterized by a small number of primordia formation and the stip is thick and long. Therefore, we expect that this new strain will save of labor and cost by without culling work.

• The Korean Journal of Mycology
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• v.13 no.3
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• pp.157-168
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• 1985

To investigate nutritive values of a feed fermented with basidiomycetes, among the isolated strains, Lyophyllum decastes (Fr.) Sing. was found with the greatest enzyme productivity and rapid mycelial growth in rice straw medium. Optimum temperature, pH and moisture content for mycelial growth and enzyme production of the strain were $25{\sim}30^{\circ}C,\;pH\;4.0{\sim}7.0\;and\;70{\sim}75\;%$, respectively. Fifteen days of culture were required for the highest enzyme productivity. Among the sub-materials added, $30{\sim}40\;%$ of rice bran and $10{\sim}20\;%$ of defatted perilla seeds were effective for the enzyme production, but caused a reduced mycelial growth. The greatest effect of an addition of inorganic salts was obtained with $0.36{\sim}0.72\;%\;of\;(NH_4)_2HPO_4$. When 40 mesh or smaller rice straw and steam treatment at $0.5\;kg/cm^2$ were used, the mycelial growth decreased, whereas the enzyme production increased. The mycelial growth and enzyme production increased when $Ca(OH)_2$ was used as the alkali treatment, but decreased with increasing concentration of NaOH. As the fermentation proceeded, the amounts of ash, reducing sugar and total nitrogen increased, but cellulose, lignin and pentosan decreased. When the rice straw was treated with alkali, the amounts of ash, total nitrogen and lignin decreased, but reducing sugar and cellulose increased. At higher NaOH concentration, the variation become greater. The in vitro dry matter digestibility of the products increased from 55.03 % at the beginning of the fermentation to 62.72 % at 45 days after fermentation. The most effective alkali treatment on the digestibility of rice straw was KOH followed by NaOH. However, the digestibility increased with increasing concentration of NaOH. The digestibility of pretreated with alkali increased after fermentation as well.