• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.428-432
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• 1999

This study was performed to investigate the possible effect of sunlight on the reduction or degradation of mycelia and aflatoxins. The mycelia and aflatoxins were produced by Aspergillus parasiticus ATCC 15517 in a yeast-extract sucrose broth (YES) and potato-dextrose agar (PDA) and then exposed to sunlight. The weight of mycelia was decreased to 76.8% in 8 hours and to 66.7% in 168 hours(p<0.05). The total aflatoxin level was significantly decreased to below 50% (46.3% in the YES broth and 49.6% in the PDA) in 8 hours (p<0.05). After 168 hours, a 90.4％ degradation of aflatoxin in the YES broth and a 77.2% degradation of aflatoxin in the PDA was observed, respectively (p<0.01). The results showed that the degradation ratios of total aflatoxin level increased with increased exposure time to sunlight. These results indicate that sunlight could be an effective factor in aflatoxin degradation although its effect on mycelia was less pronounced.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.183-191
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• 1990

Soy milk prepared from soy protein concentrate was added with each of four types of milk products. Acid production and growth of five species of lactic acid bacteria(LAB) in soy milk and sensory property of soy yogurt were investigated. Acid production by LAB increased in proportion to concentration of milk products added to soy milk. Among the four milk products tested, whey powder or skim milk powder stimulated acid production by LAB more than whole milk powder or modified milk powder. Stimulating effect by whey powder on acid production by LAB was greater than other milk products at low concentration. Acid production by LAB in soy milk added with glucose or milk products significantly increased during fermentation. Sensory property of soy yogurt added with whole milk powder or skim milk powder was better than that of reference (soy yogurt added with glucose) while sensory property of soy yogurt added with whey powder or modified milk powder was Inferior to that of reference.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.623-630
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• 2017

The purpose of this study was to investigate the possibility of applying cosmetic material about extracted from Lycii Fructus seed supercritical fluid. This study was conducted to evaluate the anti-melanogenesis effect and antimicrobial activity about the extracts from Lycii Fructus seed. These researches studied for emulsion physical stability of pH, viscosity, particle size from emulsion containing Lycii Fructus seed extract. As a result, the supercritical fluid extract from Lycii Fructus seed significantly inhibited melanin synthesis by 81.86 % at the concentration $750{\mu}g/mL$. Antimicrobial effects of extract was determined against Staphylococcus aureus, Candida albicans, Escherichia coli. except by Staphylococcus epidermidis. The physical stability of viscosity and pH on the emulsion containing Lycii Fructus seed extract were stable for 28 days. Emulsion containing Lycii Fructus seed extract did not change particles at observation into optical microscope. These results suggest that extracts from Lycii Fructus seed may have value as the potential cosmetic formulation.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.95-100
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• 2001

In countries that consumes rice as a main staple, rice hulls are natural resources composed of a large amount of organic compounds and high uniformity in size. Rice hulls are expanded to get rid of a defect in untreated rice hulls and to be used as a hydroponic substrate. Research on rice hulls is continuing for the agricultural application. This research was conducted to stabilize rhizosphere pH of the expanded rice hull substrates because of high pH caused by repeated use in ERH(expanded ride hull) substrates and without increasing the cost of developing new substrates. Sphagnum peatmoss (pH 3.0-4.0) wee mixed with the expanded rice hull substrate in the ratio of 10% (v/v), and this ratio kept the pH range of 6.0 to 6.5 in the root area of tomato plants during growth and at the time of harvest of tomato fruits. Also absorbtion of nutrients was highly increased. The yield increased from 1,051 to 1,266 kg per tomato plant which were harvested by two clusters.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.329-336
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• 1987

Antagonistic interaction between glyphosate and some herbicides in effects of post-emergence application on cut grass and of pre-emergence application on some weed species including barnyardgrass was evaluated with pots in plastic house. By addition of oxyfluorfen to glyphosate, the weeding efficacy on cutgrass was visually evaluated as promotive in both weeding rate and efficacy. However, by alachlor, simazine, gluphosinate or quizalofop-ethyl showed delayed weeding rate, and by paraquat, the promotive in rate but lower in efficacy, respectively. Fresh weights of cutgrass at 30 days after the lower-rate application has generally indicated the lower weeding efficacy than that from glyphosate alone. Even at higher rate application, the addition of alachlor or simazine to glyphosate has still indicated the lower efficacies. As a result of interaction analysis by Colby method, no synergism was detected from any treatments, and the combinations of simazine or paraquat to glyphosate in lower mixing rate showed significant antagonism at 5% probability level of DMRT. On the annual weed species including barnyardgrass, the significant soil-residual weeding efficacies were recognized by addition of any rate of oxyfluorfen, alachlor, simazine and higher rate of quizalofop-ethyl to glyphosate, respectively.

• Food Science and Preservation
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• v.18 no.1
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• pp.1-6
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• 2011

Kochujang-gulbi, a Korean traditional food, was prepared with kochujang and freeze-dried gulbi slices. Kochujang-gulbi was treated with high hydrostatic pressure (200, 400 and 600 MPa) and gamma-irradiation (7, 10, 20 and 30 KGy) to improve its quality and shelf-life. The pH of high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples did not significantly different compared to that of control. However, Hunter L value slightly increased, and Hunter a and b values decreased by high hydrostatic pressure and gamma-irradiation treatment. During storage, the pH and color of high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples did not significantly changed. The VBN and TBA level decreased by the increase treatment of high hydrostatic pressure and then slowely increased during storage. The VBN and TBA level of kochujang-gulbi samples treated by the strong gamma ray emission slowely increased during storage. In particular, gamma-irradiation treatment was very effective to sterilize microorganisms when compared to that of high hydrostatic pressure in kochujang-gulbi products. In addition, the high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples shown significantly lower total viable cell number than control for the 20 days of storage at room temperature with retort pouch packaging.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.301-301
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• 2009

겨울철 농경지 이용율 제고 및 자연경관 조성을 위하여 녹비작물을 재배하는 면적이 지속적으로 증가하고 있는 추세이다. 그 동안 녹비작물에 대한 연구는 주로 파종적기, 작물에 대한 양분공급효과 및 타감 효과 등에 집중되어왔다. 본 연구에서는 토양 중 양분공급 및 미생물활성의 경시적 변화, 잡초억제 및 작물생육에 대한 녹비작물의 투입효과를 알아보기 위하여 수행하였다. 국립농업과학원 구내포장에서 2007년 9월 하순에 헤어리베치(8kg/10a)와 호밀(10kg/10a) 종자를 파종한 후, 이듬해 4월 하순에 수확하여 토양에 환원하였다. 질소공급량은 화학비료(15.2kgN/10a) 대비 헤어리베치(32.2kg/10a, 212%), 호밀(9.2kg/10a, 60%) 및 헤어리베치+호밀(15.5kg/10a, 102%)로 헤어리베치의 질소공급효과가 매우 높았다. 토양 무기태질소 함량은 녹비 처리 후 30일경에 최대에 도달하였으나, 호밀 처리구는 조사기간 동안 큰 변화가 없었다. 토양 유기물 함량의 변화는 시험 전(10DBI)과 비교하여 큰 차이를 보이지 않았으나, 녹비환원 후 10일경에 일시적으로 감소하는 경향을 보였는데 이는 녹비환원 후 토양경운에 의한 영향으로 판단되며, 무기태질소와는 달리 호밀처리구의 유기물함량이 지속적으로 증가하는 경향을 보였다. 토양 탄수화물(수용성 당)은 시험 전에 가장 높았으며, 시간의 경과와 함께 서서히 감소되는 양상을 보였으며 토양 미생물탄소 및 미생물질소의 양은 녹비처리구가 화학비료 처리구에 비해 높았으며 녹비환원 후 50일 까지는 증가하다가 그 이후에 감소하는 경향을 보였는데 이는 토양의 무기태질소 및 탄수화물과 밀접한 관계가 있는 것으로 판단되었다. 녹비처리 후 85일경에 잡초발생량을 조사한 결과, 화학비료 처리구에 비하여 헤어리베치 처리구는 40%, 호밀 처리구는 68%, 헤어리베치+호밀 처리구는 40%의 잡초억제효과가 있었다. 고추과의 수량은 화학비료 처리구(702kg/10a)>헤어리베치(694kg>10a)>헤어리베치+호밀(361kg/10a)>호밀(179kg/10a)의 순으로 나타났다.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.19-28
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• 2014

Research was initiated in greenhouse to investigate effects of polymer, calcium, perlite and chitosan on the growth of Kentucky bluegrass (KB). A total of 24 treatment combinations were used in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite, and chitosan in soil organic amendment (SOA). Significant differences were observed in germination rate, turfgrass coverage, turfgrass density and top growth among treatments. Germination rate, density and plant height varied with time after seeding. A proper mix of WSP is considered to be lower than 3% for turfgrass coverage and density. Regarding survival capability and top growth, however, it was good under 6%. Overall KB growth was more influenced by calcium and perlite than chitosan. Calcium and perlite were the most effective elements for early survival capacity and turfgrass density, respectively. But no effect was found by chitosan. Top growth increased with three elements, being perlite > calcium > chitosan. The chitosan was effective in early germination, but there was no effect on top growth until 3 weeks, when compared with others. A further study is needed for investigating the effect of these materials on the growth characteristics in mixtures of sand and SOA before a field application.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.111-117
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• 1998

Objectives : 'First-night effect' has been a well-known concept since 1960's. It is important because it is one of the major factors to be considered in assessing the reliability of polysomnographic data. However, 'reverse first-night effect' has also been described, resulting in the inconsistency of conceptualization. We attempted to investigate on the first-night effect in adults by having each of them take two nights of polysomnography in a controlled environment. Young healthy adult volunteers were chosen as subjects in order to rule out age- or health-related confounders. Methods : Polysomnography was performed on eight male medical students (mean $age=23.5\;{\pm}\;0.9$) for two nights with Grass model 78 polysomnograph. We scored manually under the standard protocol each epoch of the sleep records. Sleep variables were obtained and compared between the two nights. Results : Sleep period time(SPT) and total sleep time(TST) of the third fraction of night were significantly longer on the first night than on the second night (p<0.05). However, other sleep variables such as percentage of each sleep stage, sleep latency, REM sleep latency, number of waking, and sleep efficiency were not different between the two nights. Conclusion : We could not confirm the existence of first-night effect in this study. In healthy young male adults, it may not happen at all or may happen to a very negligible degree. Young healthy adults may have more adaptability to a new sleep environment. Also, the provision of a reasonably comfortable sleep environment could have helped them with abolition of first-night effect.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.106-115
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• 1998

This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.