• Toxicological Research
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• v.13 no.4
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• pp.435-447
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• 1997

l-Muscone is synthesized for use as substitutive material of musk which is the active ingredient of woohwangchungsimwon. The objective of this investigation was to evaluate the acute and subacute toxicity of l-muscone in rats. In oral acute toxicity test, SPF Sprague-Dawley male and female rats were gayaged with l-muscone of two doses(0, 5.0 g/kg). No dead animal and abnormal autopsy findings were found in control and treated group. Body weights were slightly decreased in both sexes of rats treated with 5.0 g/kg. Therefore, oral $LD_{50}$ of l-muscone was consider to be higher than 5.0 g/kg in male and female rats. In intraperitoneal acute toxicity test, rats were injected intraperitoneally with dosages of 0, 1,000, 1,316, 1,732, 2,279 and 3.000 mg/kg. Decreased body weights and motor activities were observed at high dose group. Intraperitoneal $LD_{50}$ of l-muscone were 1,920 mg/kg in male and female rats. In the subacute study, l-muscone was administrated orally to both sexes of rats for 4 weeks as several doses(0, 10, 100 and 1,000 mg/kg). There were neither dead animals nor significant changes of body weights during the experimental period. In addition, no differences were found between control and treated groups in clinical signs, urinalysis, hematology, serum biochemical analysist and other findings. Above data suggest that no observed adverse effect level of l-muscone in rats might be over 1,000 mg/kg/day in this study.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.277-280
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• 1994

This study was conducted to obtain some basic information needed for the propagational system of high quality garlic trough the culture of healthy tissues. non shoot-tips of bulbil obtained in mid May were cultured on MS medium containing 8% sucrose supplemented with 0.1 mg/L NAA, in vitro bulbli were formed, but the shoots were formed at the early to middle in June. Multiple shoots were induced by the culture of receptacles on MS medium supplemented with 0.1 mg/L NAA and 10mg/L BA..Among the flower bud, bulbil and receptacle, receptacle showed most suitable in terms of shoot formation efficiency, More than 50 shoots per single involucre were produced under the optimum condition. Results indicate that in vitro culture of involucre has a high potential for the micropropagation of high quality seed bulbs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.826-833
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• 2001

The effects of Monascus koji on the fermentation and quality of mul-kimchi (CCK) were investigated. Monascus koji at a final concentration of 1% against total amounts of saline and salted Chinese was added to MK and CCK, respectively, and fermented at 1$0^{\circ}C$. The koji of MK and CCK had a little effect on pH and acidity. Antimicrobial effect of water extracts from Monascus koji showed at the concentration of 3% for L. brevis and 5% for L. acidophilus and L. bulgaricus, respectively. Whereas no effect was founded in the strains of L. plantrum, L. GG and Leuc. mesenteroides. It was possible to control the color of kimchi by using Monascus koji instead of red pepper. Especially, color acceptability of MK added the koji was greatly improved. The content of reducing sugar and the score of sweet taste were slightly increased in the kimchi added the koji, whereas no great difference in the crispness was found. Overall acceptability of CCK was not apparent, but that of MK was greatly enhanced. It is apparent that the inhibitions of HMG-CoA reductase in MK and CCK added 1% Monascus koji were 10~20 and 7~16%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.474-481
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• 2019

This study evaluated the chronic effects of $NO_3-N$ on juvenile blackhead seabream Acanthopagrus schlegelii. The experiment used six identically configured recirculating aquaculture systems (435 L), with three tanks (70 L) each. The $NO_3-N$ concentrations studied were 0 (control), 62.5, 125, 250, 500, and 1,000 mg/L $NO_3-N/L$. Thirty juvenile blackhead seabream ($18.8{\pm}2.2g$) were stocked in each tank. Growth and hematological changes were evaluated after 120 days. At the end of the experiment, the growth, survival, and cortisol levels indicated that blackhead seabream were healthy in 500 mg $NO_3-N/L$. However, insulin-like growth factor I (IGF-1) and the IGF-1 receptor were significantly lower at 250, 500, and 1,000 mg $NO_3-N/L$ than in controls (62.5 and 125 mg $NO_3-N/L$). Juveniles were likely affected at a much lower $NO_3-N$ concentration than 250 mg/L $NO_3-N/L$ in terms of IGF-1 and the IGF-1 receptor. Therefore, for the sake of long-term fish welfare, the $NO_3-N$ should be maintained at lower than 250 mg/L for blackhead seabream in recirculating aquaculture systems.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1324-1329
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• 1999

This study was carried out to investigate the distribution and characteristics of Listeria monocytogenes isolated from frozen Mandoo and pizza in 1998. A total 72 samples were examined and USDA, FDA and modified cold enrichment methods were used for the detection of Listeria spp. Overall prevalence of L. monocytogenes in frozen foods was 9.7% and L. monocytogenes was isolated from 11.1% of frozen Mandoo and 5.6% of frozen pizza. The highest detection rate of Listeria spp. in frozen Mandoo was found at USDA method and the serotype of L. monocytogenes isolates was 4. Isolated L. monocytogenes was confirmed by PCR method with Hly 1 and 2 as primers. It would be necessary to develop more rapid and specific method to isolate and confirm L. monocytogenes from foods because USDA and PCR methods used in this study took 3-4 days. D value of L. monocytogenes isolate in tryptic soy broth was 49.2 sec at $60^{\circ}C$ and 8.8 sec $at\;65^{\circ}C$, and D value of L. monocytogenes in foods with high distribution rate of Listeria spp. would be necessary to evaluate for the safe use of frozen foods.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.733-739
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• 2004

Model for optimally dimensioned PE film bag was developed according to fruit size to maintain best quality of 'Fuyu' persimmon in modified atmosphere packaging (MAP) storage based on relationship between quality and oxygen and carbon dioxide in PE film bag. Harvested persimmons were graded into five sizes, and average weights were LL:261, L:217, M:188, S:168, and SS:154 g. Five fruit units of each grade were optimized in five PE film bag sizes of $150{\times}376,\;140{\times}357,\;130{\times}344,\;130{\times}333,\;and\;120{\times}3l8\;mm$. To minimize quality deterioration such as softening and discoloration, optimal oxygen and carbon dioxide concentrations in PE film bag were 0.5-1.0 and 6.0-8.0%, respectively, and optimal thickness of PE film bag according to fruit size were LL:45, L:50, M:55, S:60, and $SS:65\;{\mu}m$. For all fruit sizes, model for PE film bag area $(mm^2)$ was good quadratic simple equation by fruit weight (g): $Y=-4055.707+627.993X_1-0.701{X_1}^2$. Model far optimal oxygen and carbon dioxide (Y) concentration in PE film bag was suited to linear multiple equation by fruit weight $(X_1,\;g)$ and PE film thickness $(X_2,\;{\mu}m)$. Equations for oxygen and carbon dioxide concentrations (%) were $Y=5.798-0.0109X_l-0.0491X_2\;and\;Y=-2.427+0.01927X_l +0.09646X_2$, respectively.

• Journal of Environmental Science International
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• v.27 no.1
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• pp.47-53
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• 2018

In this study, high-purity silver nanocolloids were synthesized by an electrolytic reaction, and the effect of temperature on the nanocolloid concentration was analyzed by performing the reaction at $70^{\circ}C$ and $90^{\circ}C$. The antibacterial properties of the thus-synthesized silver nanocolloids were also studied. When the synthesis was performed at $90^{\circ}C$, the concentration of silver nanocolloid increased to 14 mg/L after 5 min, 1756 mg/L after 30 min, and 2147 mg/L after 60 min. The concentration of silver nanocolloid synthesized by electrolytic reaction at $70^{\circ}C$ and $90^{\circ}C$ for 60 min was 1,882 mg/L and 2147 mg/L, respectively. The preferred temperature at which the electrolytic synthesis is performed is $70^{\circ}C$ to obtain high concentrations of 1,000 mg/L or more. The antibacterial performance of the thus-synthesized silver nanocolloids was 99.9% for E. coli and 99.5% for Pseudomonas aeruginosa.

• Journal of the Korean Mathematical Society
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• v.56 no.4
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• pp.1131-1158
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• 2019

An ideal right-angled pentagon in hyperbolic 4-space ${\mathbb{H}}^4$ is a sequence of oriented geodesics ($L_1,{\ldots},L_5$) such that $L_i$ intersects $L_{i+1},i=1,{\ldots},4$, perpendicularly in ${\mathbb{H}}^4$ and the initial point of $L_1$ coincides with the endpoint of $L_5$ in the boundary at infinity ${\partial}{\mathbb{H}}^4$. We study the geometry of such pentagons and the various possible augmentations and prove identities for the associated quaternion half side lengths as well as other geometrically defined invariants of the configurations. As applications we look at two-generator groups ${\langle}A,B{\rangle}$ of isometries acting on hyperbolic 4-space such that A is parabolic, while B and AB are loxodromic.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.37-43
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• 2018

Optimization of the lactic acid fermentation process was carried out to produce an old antler extract fortified with ${\gamma}$-aminobutyric acid (GABA). An old antler extract (OAE; 5%, w/v) obtained using a herbal extractor showed the highest contents of solids (1.75%) and proteins ($980{\mu}g/mL$). It also showed the highest total amino acid contents of $13,659{\mu}g/mL$, with glycine, proline, and glutamine concentrations of 1,945, 3,405, and $1,641{\mu}g/mL$, respectively. For the over-production of GABA, OAE was fermented with Lactobacillus plantarum EJ2014 in the presence of 0.5%, 1.5% glucose, and 3.5% MSG at $30^{\circ}C$ for 7 days. The fermented OAE showed high viable cell count of $2.0{\times}10^8CFU/mL$, pH of 6.56 and 0.77% acidity after 7 days. In particular, the acidity was greatly decreased by fermentation for 3 days, and 1.4% GABA was produced by the efficient conversion of the substrate, mono sodium glutamate.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.475-481
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• 2005

In an effort to identify a new environment-friendly algicide, we examined the ability of extracts from the leaves and stems of nine Korean oak tree species to inhibit growth of the bloom-forming cyanobacterium, Microcystis aeruginosa. At a concentration of 100 mg $L^{-1}$, five of the oak tree extracts (QAT-L, QAT-5, QAS- L, QGI-5, and QSA- L) decreased the cell density of M. aeruginosa by over 90% for 7 days. At a concentration of 20 mg $L^{-1}$, the same five extracts inhibited the growth of M. aeruginosa by approximately 50%. The minimum concentration of oak tree extracts required for effective inhibition of M. aeruginosa (20 mg $L^{-1}$) is comparable to that of the known algicide, tannic acid (17 mg $L^{-1}$), which is thought to be one of the main active ingredients in the oak tree extract. These findings suggest that oak extracts may be useful as an environment-friendly algicide to control the bloomforming cyanobacterium, M. aeruginosa, in eutrophic waters.