• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.224-230
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• 2013

BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

• Journal of Aquaculture
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• v.20 no.1
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• pp.19-25
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• 2007

For establishing a basal diet for the Pacific bluefin tuna Thunnus orientalis (PBT), feeding stimulants were initially identified by omission test using the synthetic extract of horse mackerel, Trachurus japonicus. Four feeding trials were conducted using juvenile PBT weighing $9.0{\pm}0.91\;g$ (trial 1, 2 and 3) and $1.6{\pm}0.23\;g$ (trial 4), which were originated from an artificial seedling production. The fish fed the casein diet with each test solution were added at the ratio of 100 g casein diet to 100 g jack mackerel muscle. A complete synthetic extract of jack mackerel containing all 3 fractions, amino acid, nucleotide and organic nitrogenous base, exhibited a comparable feeding stimulant activity compared to that of natural extract. The omission of nucleotide or amino acid fraction showed lower feeding activity, but the omission of other nitrogenous fraction maintained a similar feeding stimulant activity compared to that of the synthetic extract (trial 1). Inosine-5' monophosphate $Na_2$ (IMP) was identified as a major constituent for maintaining feeding activity. The mixture of L-alanine, L-glutamic acid, L-histidine, L-lysine, taurine and IMP induced a similar feeding activity compared to that of the synthetic extract (trial 2 and 3). In trial 4, the highest feeding activity was finally obtained in the mixture of L-histidine, L-glutamine and IMP, followed by the synthetic extract, the mixture of L-lysine, L-alanine and IMP, IMP and the mixture of L-histidine, L-glutamic acid, L-lysine and L-alanine. These results revealed that the mixture of L-histidine, L-glutamic acid and IMP for the proper feeding stimulant of PBT in this study.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.468-472
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• 1995

Substantial amount of caryophyllene oxide (CPO) is present in the essential oils of traditionally-used folk medicinal plants and herbal spices. The CPO, produced via chemical and/or enzymatic reaction of caryophyllene (CP), has largely being used as a flavoring component and exhibited a variety of biological activities. Now, we report the antimutagenic activity of CPO determined by Ames's preincubation test. S-9 fraction was prepared from the liver of rats treated with Arochor 1254. Anatoxin $B_1\;(AFB_1)$ and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) were used as mutagens. Reduction of mutagenicity of $AFB_1$ or IQ for S. typhimurium TA98 and TA100 by CPO was found to be a dose-dependant manner. CPO (500 ${\mu}g/plate$) reduced mutagenicity of AEB1 for S. typhimurium TA98 and TA100 to 89% and 71%, respectively. For IQ, similar results were observed against S. typhimurium TA98 and TA100, resulting in the inhibition percentage of 77% and 51%, respectively. CP also reduced mutagenicity of AEB1 and IQ for S. typhimurium TA98 and TA100, but the reduction rate was somewhat lowered relative to that of CPO. These results indicate that CPO could be developed as a potent antimutagenic flavoring agent.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.517-524
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• 2005

Despite the widespread use of chloral hydrate with hydroxyzine in the sedation of children, there is little agreement among pediatric dentists regarding its therapeutic dosage for the management of very uncooperative young children. Also, increasing concern has been raised with respect to its frequent failure to provide adequate levels of sedation when used according to the manufacturer's recommended dosage. Therefore, there has been many suggestions with respect to sedative effectiveness and safety of varying drug dosage, and some pediatric dental articles have advocated dosages exceeding manufacturer's recommendations. This study was performed to compare the effectiveness and safety in behavior management of the manufacturer's recommended dose of chloral hydrate(50mg/kg) with those of a higher dose(70mg/kg) used together with hydroxyzine(2mg/kg) and nitrous oxide(50%) when young children were sedated for dental treatment. The following results were obtained; 1. II group(70mg/kg) displayed higher mean score compared to I group(50mg/kg) with regard to the degree of sleep, crying, movement and overall behavior. The difference was statistically significant(p<0.05). 2. In comparison of success rates for sedation between the two groups, I group and II group showed 38.7% and 71.0% success rates respectively. An analysis of variance was statistically significant(p<0.05). 3. Comparing the occurrence rate hypoxia between the two groups, there were 22.6% and 19.4% occurrence of hypoxia in I group and II group. An analysis of variance was not statistically significant(p>0.05).

• Sleep Medicine and Psychophysiology
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• v.24 no.2
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• pp.106-117
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• 2017

Objectives: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder that is characterized by repetitive collapse or partial collapse of the upper airway during sleep in spite of ongoing effort to breathe. It is believed that OSA is usually worsened in REM sleep, because muscle tone is suppressed during REM sleep. However, many cases showed a higher apnea-hypopnea index (AHI) during NREM sleep than during REM sleep. We aimed here to determine the characteristics of REM sleep-dependent OSA (REM-OSA) and NREM sleep-dependent OSA (NREM-OSA). Methods: Five hundred sixty polysomnographically confirmed adult OSA subjects were studied retrospectively. All patients were classified into 3 groups based on the ratio between REM-AHI and NREM-AHI. REM-OSA was defined as REM-AHI/NREM-AHI > 2, NREM-OSA as NREM-AHI/REM-AHI > 2, and the rest as sleep stage-independent OSA (IND-OSA). In addition to polysomnography, questionnaires related to subjective sleep quality, daytime sleepiness, and emotion were completed. Chi-square test, ANOVA, and ANCOVA were performed. Results: There was no age difference among subgroups. The REM-OSA group was comprised of large proportions of mild OSA and female OSA patients. These patients experienced poor sleep and more negative emotions than other two groups. The AHI and oxygen desaturation index (ODI) were lowest in REM-OSA. Sleep efficiency and N3 percentage of REM-OSA were higher than in NREM-OSA. The percentage of patients who slept in a supine position was higher in REM-OSA than other subgroups. IND-OSA showed higher BMI and larger neck circumference and abdominal circumference than REM-OSA. The patients with IND-OSA experienced more sleepiness than the other groups. AHI and ODI were highest in IND-OSA. NREM-OSA presented the shortest total sleep time and the lowest sleep efficiency. NREM-OSA showed shorter sleep latency and REM latency and higher percentage of N1 than those of REM-OSA and the highest proportion of those who slept in a lateral position than other subgroups. NREM-OSA revealed the highest composite score on the Horne and ${\ddot{O}}stberg$ questionnaire. With increased AHI severity, the numbers of apnea and hypopnea events during REM sleep decreased, and the numbers of apnea and hypopnea events during NREM sleep increased. The results of ANCOVA after controlling age, sex, BMI, NC, AC, and AHI showed the lowest sleep efficiency, the highest AHI in the supine position, and the highest percentage of waking after sleep onset in NREM-OSA. Conclusion: REM-OSA was associated with the mild form of OSA, female sex, and negative emotions. IND-OSA was associated with the severe form of OSA. NREM-OSA was most closely related to position and showed the lowest sleep efficiency. Sleep stage-dependent characteristics could provide better understanding of OSA.

• Culinary science and hospitality research
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• v.22 no.3
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• pp.11-21
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• 2016

This study investigated the quality characteristics and retarding retrogradation of sponge cakes made with red yeast rice (RYR) flour. RYR (Monascus nuruk) is known to help digestion, smooth blood flow, and have anti-cancer, anti-microbial, and inhibitory effects against biosynthesis of cholesterol and blood pressure. This studys aim' was to find the optimal proportion of RYR flour in sponge cake. RYR sponge cakes were prepared with various levels (0, 5, 10, 15 and 20%) replacement of wheat flour and were designated as the control (without RYR), RYR5, RYR10, RYR15 and RYR20 respectively. Specific gravity was the lowest in RYR15 at 0.57, and the baking loss rate was not significantly different among the samples (p<0.05). The dough yield was the highest in RYR15 at 96.61. The moisture contents was highest in order, control, RYR5, and RYR15 at 28.67%, 28.18%, and 26.82% respectively. The L-value of crust tended to increase according to the level of RYR, but the L-value of crumb decreased in accorddance with the the content of RYR. The a-value of crust also decreased according to the level of RYR, although the a-value of crumb increased in response to higher levels of RYR. The b-value tended to decrease with increases of RYR (p<0.05). RYR5 exhibited the highest pH at 8.63, compared with RYR15 (8.57). The hardness, which was measured after cooling for 1 hour, was the lowest in RYR15 at $163.33g/cm^2$ and the springiness was not different significantly (p<0.05). Cohesiveness was the highest in RYR10 at 133.06%. The chewiness was the highest in RYR10 at $391.63g{\cdot}cm$ and lowest in RYR15 ast $169.62g{\cdot}cm$. Avrami equation showed that RYR15 and RYR20 had the lowest Avrami exponent (n) at 0.0664 and 0.4983 respectively. Time constant (1/k) was the highest in RYR15 at 200.00. Sensory evaluation revealed that RYR15 was the highest in color (5.50), flavor (4.95), sweetness (4.90), chewiness (4.75), and overall acceptability (4.60).

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.216-224
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• 1998

The objective of this study was to investigate the effect of sesame monoculture and sesame in rotation (SR) with maize. soybean. barley or rye on reduction of injury by continous cropping in sesame. Field studies were conducted for 3-years (1995~1997) at the experimental field of the Crop Experiment Station. Compared to CS (continuous sesame). SR treatments turned out to keep more organic matter and higher exchangeable cation concentrations in soils. BS (barley and sesame in a 1-year rotation) and RS (rye and sesame in a 1-yea r rotation) treatments had significantly greater available $P_2O_5$ contents in soils than CS, MS (maize and sesame in a 3-year rotation) and SbS (soybean a nd sesame in a 3-year rotation). The pH of the soils under different treatments were not significantly different. SR treatments exhibited significantly lower bulk density and higher pore space than CS. Soil microbial biomass C (SMBC) and N (SMBN) were determined by the chloroform fumigation-extraction method. SMBC and SMBN were significantly higher in soils under BS and RS than those under CS, but only during the 1 year of monitoring. MS and SbS treatments resulted in higher SMBC and SMBN than CS. The occurrence of injury by disease of sesame is the important primary factor of injury by continous cropping, but the disease occurrence with rotation did not decrease in th is experiment. Under CS treatment, the growth and grain of sesame was significantly lower than those under other treatments. Compared to CS, the increments of grain yield of sesame were 68, 63, 57 and 51% for MS, RS, SbS and BS, respectively in the first harvest. In the second harvest, they were 24% for MS, 28% for RS, 20% for SbS and 19% for BS. The average increase ratios during the two years were 41, 41, 34, and 33% for MS, RS, SbS and BS, respectively.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Journal of Life Science
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• v.14 no.4
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• pp.650-656
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• 2004

Oryza grandiglumis (CCDD, 2n=48), one of the wild rice species, has been known to possess fungal-,bacterial-, and insect-resistance against sheath blight, rice blast, bacterial leaf blight and brown plant hopper (Nilaparvata lugens). To rapidly isolate differentially expressed genes responding to fungal and wounding stress, wounding and yeast extract were treated to O. grandiglumis for 24 hrs. Suppression subtractive hybridization (SSH) method was used to obtain differentially expressed genes from yeast extract and wounding treated plants. Seven hundreds and seventy six clones were obtained by subcloning PCR product, and colony array and screening were carried out using radio-isotope labeled cDNA probes prepared from the wounding and yeast extract treated plants. One hundred and fifteen colonies were confirmed as true positive ones. Average insert size of the clones were ranged from 400 bp to 700 bp and all the inserts were sequenced. To decide the identity of those clones, sequences were analyzed by sequence homology via GenBank database. The homology search result showed that 68 clones were matched to the genes with known function; 16 were related to primary metabolism, 5 to plant retrotransposons, 5 to defense related metallothionein-like genes. In addition to that, others were matched to various genes with known function in amino acid synthesis and processing, membrane transport, and signal transduction, so on. In northern blot analysis, induced expressions of ogwfi-161, ogwfi-646, ogwfi-663, and ogwfi-695 by wounding and yeast extract treatments were confirmed. The result indicates that SSH method is very efficient for rapid screening of differentially expressed genes.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.297-305
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• 2018

Purpose: This study aimed to analyze stress distribution and maximum von Mises stress generated in intracoronal restorations and in tooth structures of mandibular molars with various types of cavity designs and materials. Materials and Methods: Three-dimensional solid models of mandible molar such as O inlay cavity with composite and gold (OR-C, OG-C), MO inlay cavity with composite and gold (MR-C, MG-C), and minimal invasive cavity on occlusal and proximal surfaces (OR-M, MR-M) were designed. To simulate masticatory force, static axial load with total force of 200 N was applied on the tooth at 10 occlusal contact points. A finite element analysis was performed to predict stress distribution generated by occlusal loading. Results: Restorations with minimal cavity design generated significantly lower values of von Mises stress (OR-M model: 26.8 MPa; MR-M model: 72.7 MPa) compared to those with conventional cavity design (341.9 MPa to 397.2 MPa). In tooth structure, magnitudes of maximum von Mises stresses were similar among models with conventional design (372.8 - 412.9 MPa) and models with minimal cavity design (361.1 - 384.4 MPa). Conclusion: Minimal invasive models generated smaller maximum von Mises stresses within restorations. Within the enamel, similar maximum von Mises stresses were observed for models with minimal cavity design and those with conventional design.