• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.209-218
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• 1997

This study was carried out to obtain the basic data for artificial culture of Grifola umbellata. The optimal condition for the mycelial growth was obtained at $20^{\circ}C$ and pH 4, respectively. G. umbellata showed the most favorable growth on the Hoppkins media. Carbon sources such as glucose, fluctose and manitol were favorable for stimulating a mycelial growth of G. umbellata. Valine, one of nitrogen sources also appeared to be favorable to a mycelial growth. The optimum C/N ratio was about 30:1 in case that 1% glucose as carbon source was mixed with the basal media. Lactic acid as organic acid was most favorable to the mycelial growth. Also, thiamine-Hcl as vitamin source was favorable. The mineral nutrient of $FeSO_4$ or $MgSO_4$ was most favorable to G. umbellata, and its optimal concentration was about 0.01% in $FeSO_4$ and 0.1 % in $MgSO_4$ respectively. Among 4 different cereal extract media, polished rice extract medium which was mixed with silkworm pupae was most suitable for a favorable growth of G. umbellata.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.1
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• pp.1-22
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• 1999

In order to investigate various physical and biological properties of dental magnetic attachments studies on retentive characteristics, corrosion properties, cytotoxicity of different magnetic systems for dental applications were done. For the study of retentive characteristics changes of retentive force by increasing air gap, wear properties of various attachment systems and loss of magnetic force by heat treatment were measured. Forte study of corrosion property of magnet covering metal electrochemical corrosion was done in artificial saliva and 0.9% NaCl solution between $-1,000mV_{SCE}\;and\;+1,000mV_{SCE}$. Anodic polarization curves are obtained about 6 types of samples and 2 types of solution. Corroded surfaces were examined with metallurgical microscope, scanning electron microscope and surface profilometer. For the study of cytotoxicity of magnetic attachment and its field cell growth and agar overlay test were done. The results of this study were as follows. 1. In Magnetic attachments using closed circuit retentive force at zero air gap was greater than magnets using open circuit, but decrease of retentive force by increasing air gap was also greater than open systems. 2. After 40,000 cycles of wear test all mechanical attachment resulted in varing degree of retention loss but in magnetic attachments no loss of retentive force was observed. 3. The magnetic attachment using Neodymium magnet showed early loss of retentive force about $200^{\circ}C$ but attachment using Samarium magnet showed some resistance to heat treatment and complete retention loss was observed about $500^{\circ}C$. The keeper was not influenced by heat treatment in retention. 4. In electrochemical corrosion test Dyna magnetic attachment covering metal showed the highiest corrosion resistance and Shiner magnet covering metal showed the least corrosion resistance and examination of corroded surface with metallurgical microscope, scanning electron micro-scope and surface profilometer also showed same results with anodic polarization corves. 5. The result of cell culture tests on the magnet covered with metal showed least recognizable cytotoxicity.

• Journal of Aquaculture
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• v.20 no.1
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• pp.31-40
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• 2007

To find out the effect of the spat planting time and environmental factors in the arkshell, Scapharca broughtonii (Schrenck), we investigated the growth, survival rate of arkshell and habitat characteristics in Gamak Bay, Yeoja Bay and Saryang Island. We planted artificial spats of arkshell in Gamak Bay and Yeoja Bay at November 2004, and also planted domestic and Chinese natural spats in Saryang Island at March 2005. We measured growth, survival rate of arkshell, physiochemical parameters of the water mass (water temperature, salinity, dissolved oxygen, nutrients and chlorophyll a) and characteristics of the sediment (oxygen penetration depth, oxygen microprofiles, ignition loss and chemical oxygen demand) by monthly. The cumulative survival ratio of arkshell in Gamak Bay was the highest at December, whereas the ratio of arkshell in Yeoja Bay was recorded as 0% at October. The monthly growth rates of arkshell length in Gamak Bay and Yeoja Bay were the highest in May and the growth rate of the Korean arkshell in Saryang Island was higher than Chinese ones significantly. The high mortality (> 65%) of the arkshell in Yeoja Bay during summer probably caused by high water temperature, inflow of low salinity water, and low dissolved oxygen concentration in sediment. The concentrations of nutrient and sediment COD were considered to play an important role in the monthly survival ratio of arkshell in Gamak Bay and Sarayng Island. We suggest that the growth and mortality of arkshell might be influenced to the planting time of spat and the habitat characteristics.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.123-128
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• 1998

Implantation rates remain low following human in vitro fertilization (IVF). Suboptimal culture conditions may limit the ability of embryos to hatch as blastocysts, and artificial opening of the zona pellucida has been proposed as a means to promote subsequent hatching (assisted hatching). In this study, assisted hatching (AH) by zona drilling using acidic Tyrode's solution was performed in 320 patients, due to their age of more than 38 years (group A), the thick zona pellucida (group Z; $ZP\geq0.18{\mu}m$), and failures in implantation more than 3 times in previous IVF-ET trial (group P). This study was designed firstly, to study the effects of AH on the outcomes of IVF-ET according to the indications and secondly, to verify the appropriate application of AH. The results were as follows; 1. There was no difference in pregnancy rate between AH group (26.6%) and non-AH group (26.5%). 2. Assisted hatching (AH) showed significantly higher pregnancy rate of the patients with thick zona pellucid a than those of the patients with age factor and with the history of repeated implantation failure. But in the patients with age factor only, AH resulted in higher pregnancy rate. 3. Interestingly, the patients with complex factors including zona factor (Z: 33.9%; ZA: 30.4%; ZP: 31.6%; ZAP: 21.4%) showed higher pregnancy rates than other complex factors excluding zona factor (A: 24.4%, P: 0%; AP: 10.8%). From these results, AH is more helpful to the patients with thick zona pellucida rather than patients with older age and/or previous repeated implantation failure.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.107-117
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• 1998

The cultivation for development of Ascaris suum from the second-stage larvae($L_2$) embryonated egg and the third-stage of rat-derived larvae($L_3$) recovered from lung of rats were performed to use the screening test of anthelmintics in vitro. The preparations of larvae for cultivation were that the artificially-hatched $L_2$ incubated the embryonated eggs of Ascaris suum in 0.1% formalin solution at $25^{\circ}C$ for 28 days and the rat-derived larvae($L_3$) recovered from the lung of rat infected with the embryonated eggs of Ascaris suum on 7 days after infection(DAI). The cultivation for development of Ascaris suum from the embryonated eggs($L_2$) and the rat-derived larvae($L_3$) for 14 days in RPMI medium 1640(with 5% bovine calf serum) were as follows : 1. The sizes of the liberated larvae($L_2$) which were artificially hatched from embryonated eggs with glass beads(diameter 5mm) were $190{\sim}250{\mu}m$ on 1 days in culture(DIC). The second-stage larvae were molted into third-stage larvae(early $L_3$; $250{\sim}300{\mu}m$) and the features of these larvae were first observed such as cephalic cuticle, esophageal lumen and anus etc. on 5 DIC and the sizes of late third-stage larvae were $250{\sim}450{\mu}m$ on 10 DIC. The sizes of early fourth-stage larvae($L_4$) were $500{\sim}700{\mu}m$ and the features of these larvae were more pronounced in internal organs on 15 DIC. 2. The sizes of third-stage larvae($L_3$) recovered from the lung of rats were $1,340{\sim}1,370{\mu}m$ and the feartures of cephalic cuticle, esophageal lumen, intestine, rectum, anus were visualized by inverted microscope on 1 DIC. The fourth-stage larva($L_4$) completed by third ecdysis were recognizable and sizes of early fourth-stage larvae were developed as $1,400{\sim}2,200{\mu}m$ on 5 DIC. The sizes of middle fourth-stage of larva were $1,900{\sim}2,300{\mu}m$ and the thickened epithelial rectum was observed on 10 DIC. The rectum and anus of late fourth-stage larva($L_4$ $2,500{\sim}3,200{\mu}m$) had developed completely in RPMI medium 1640 on 15 DIC.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.101-104
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• 2016

Curvularia leaf blight of creeping bentgrass (Agrostis stolonifera) putting green by caused Curvularia trifolii was observed in Hapcheon, Korea. In July to September 2014, curvularia leaf blight developed on leaf blades of creeping bentgrass as small water-soaked lesions that subsequently turned into dark-colored, necrotic spots. The spots were expanded and became gray, grayish-brown, or light brown, circular to oblong lesions with purple to dark brown borders that often were surrounded by a yellow halo. The necrotic lesions coalesced, became irregular in shape and caused tip or complete blighting of the leaves. Blighted leaf blades appeared grayish-white to tan. The fungus was identified by morphological characters and 16S rDNA sequencing as C. trifolii. Conidia of the pathogen were short, with predominantly 3-septa, straight or often curved, with end cells frequently paler than intermediate cells. Size of the 3-septate conidia in culture are $26{\sim}28{\times}11{\sim}12{\mu}m$. Pathogenicity of the fungus was proved by artificial inoculation on the host. This is the first report of C. trifolii causing leaf blight on creeping bentgrass in Korea.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.3
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• pp.50-57
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• 2015

A traditional garden in Korea has diverse cultural, historical values, such as the then phases of the times, life phase, culture and art, etc. because it was developed on the basis of the harmony between nature and artificial structures. However, in reality, it's urgent to do efficient, continuous maintenance of traditional gardens which are being damaged and lost due to the problems like an owner's aging, inheritance, and lack of management, etc., especially in case of private property which was designated as a cultural property among such traditional gardens under the Cultural Properties Protection Law. Accordingly, this study conducted this research in a bid to use these research results as basic evidentiary materials for suggesting directivity in introduction of park planning of traditional gardens in folk houses in the near future by implementing the case investigation of transformation into public parks from traditional private gardens in Japan, which is putting the newly introduced park planning to efficient use, together with its systematic management, and the survey on domestic traditional gardens in folk houses status, as well as the hearing-based survey on a traditional gardens in folk houses owner's level of willingness to accept the introduction of parking planning. As a result, this study could confirm that in case of traditional gardens in Japan, they are mobilizing the revenue from admission fees for traditional gardens maintenance by incorporating the main entity of possession, and Japan is promoting transformation of traditional gardens into parks on the basis of use and preservation through the connection with local governments and research institutes. In addition, as a result of surveying domestic traditional gardens in folk houses, it was found that most of the garden owners had hardships in its management, and they were positive about systematic maintenance of gardens through park planning.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.185-192
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• 1999

The present study was performed to investigate the efficacy and safety of laser assisted hatching (AH) on mouse embryos. Non-contact $1.48{\mu}m$ diode laser system used to create a precise hole on zona pellucida. 2-cell embryos were collected from the mice (ICR) that had the coitus vaginal plug confirmed at 48 hours after hCG injection. Collected 2-cell embryos were cultured in the HTF medium supplemented with 0.4% BSA. For experiments, embryos at 8-cell stage were used after 18-22 hours in culture. After assisted hatching, the embryos were further cultured in HTF medium containing 0.1% PVP (anti-hatching system) for 3 days. For evaluate efficiency of laser on mouse embryo hatching, the effect of AH methods (acidic tyrode, pronase and laser), the number of artificial holes (1, 2 and 3 hole) and the irradiation time of laser (2, 4, 6, 8 and 10 ms) were examined. Hatching rates of laser AH group (95.2%) was significantly higher than that of control group (50.8%), but there was no differences among the laser (95.2%), acidic tyrode (100%) and pronase (98.5%) groups. Hatching rates of the number of zona pellucida opening by laser, there were no differences among the 1 hole (87.5%),2 hole (92.1%) and 3 hole (85.9%) groups. Developmental and hatching rates of embryos according to laser irradiation time were similar in the treatment groups. Therefore, these results suggest that laser AH using non-contact $1.48{\mu}m$ diode laser is a simple and accurate and effective procedure for AH. Based on these results, laser AH could be use safely for human ART program.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.153-159
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• 2006

The pine mushroom fruit body have a harvest only from natural pine forest instead of artificial culture like other edible mushrooms until now on. We investigated the interrelationship between pine mushroom colonies and insect/invertebrates fauna, and changes of their seasonal populations. Two famous pine mushroom producing district were selected on Bong-wha and Gan-sung Eup, and were surveyed on the ground and in the soil with/without pine mushroom hyphae per month from June to November, 2005. There was some difference in collected Insects and invertebrates between two producing districts. Total number of collected species and individuals were 73 and 22, and 63 individuals with 19 species in Bon-wha and Gan-sung area, respectively. Otherwise, there were many mites and nematodes were living in soil with mushroom hyphae. The population densities of mites were Increased to November from June, however, the population of nematodes were fluctuated with low in hot weather and high in cool.