• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.955-959
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• 2006

Effects of chlorine dioxide ($ClO_2$) on weight loss, polyphenol oxidase activity, and microbial change of fresh mushrooms (Agricus bisporus Sing) were investigated. Mushrooms were treated with 5, 10, and 50 ppm of $ClO_2$ solution. Mushrooms were stored at room temperature and $4^{\circ}C$. Weight loss for $ClO_2$ treated mushrooms was smaller than that of the control group. Polyphenol oxidase activity of the $ClO_2-treated$ samples stored at room temperature increased until day 2 of storage and then decreased, and the activity of the samples stored bacteria, yeast and mold counts than the control during storage. Aerobic bacterial counts for 50 ppm of $ClO_2$ treatment at $4^{\circ}C$ increased from $1.62{\times}10^2\;CFU/g\;to\;1.66{\times}10^7\;CFU/g$ at day 10 of storage, while control groups were from $1.00{\times}10^3\;CFU/g\;to\;3.72{\times}10^8\;CFU/g$. These results indicate that $ClO_2$ treatment could be useful in improving the quality and microbial safety of mushrooms.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.159-172
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• 2021

This study is an action study that plans a instructional strategy for improving experimental activities and interactions in online science classes and suggests improvement plans based on the results. To this end, from July 7 to September 9, 2020, the 'Earth and the Moon' unit class was conducted for 20 6th grade elementary school students located in G Metropolitan City. For the class, smart devices and alternative experiments were planned in the experimental activity category, and an online chat room and Q&A strategy were planned in the interaction category. Among the collected data, class activity papers, homework assignments, reflection journals, online conversation contents, and Q&A contents were input into the matrix and analyzed by writing analytical texts. As a result of the implementation, smart devices and alternative experiments provided opportunities for exploration, but there was a risk of misconception formation and hindered experimental activities. The online chat room and Q&A provided opportunities for communication and examination and feedback on scientific concepts. Through this action study, the researcher was able to reflect on the class while writing class reflection notes, and suggested the role of smart devices in terms of the effectiveness and efficiency of science classes.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.19-25
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• 2013

This study focused on the usefulness of plant extracts for a city organic farm. Insecticidal activity of 8 plant species, plants crude extracts by ethanol and water, against third instar larvae (susceptible strain) of Plutella xylostella was evaluated in this study. Ethanol(25%) extracts of plant materials had better insecticidal activity than water extracts at the room temperature. Insecticidal activity were investigated by leaf disc spray method. Five plant extracts (Capsicum annuum, Chelidoniun majus, Leonurus sibiricus, Coptis japonica, Mentha piperascens) showed over 50% insecticidal activity to P. xylostella at the concentration of $1500mg{\cdot}L^{-1}$. Extract of C. annuum showed the highest insecticidal activity (83.3%) against P. xylostella. Phytotoxicity was not observed on Raphanus sativus and Brassica campestris with spray application. Seed germination and growth of two plants were not affected. Extract of C. japonica revealed 73.3% control efficacy against P. xylostella of R. sativus and showed 70% control efficacy against those of B. campestris, respectively, in plastic house. Insecticidal activity against various insects was observed in C. japonica extract as 87.4% for R. sativus and 74.3% for B. campestris in the field. These results suggested that extracts of C. annuum, C. japonica showed the highest insecticidal activity, and could be used as city farm insecticides for organic farming.

• Korean Journal of Medicinal Crop Science
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• v.25 no.1
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• pp.37-44
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• 2017

Background: The light emitting plasma (LEP) has recently attracted attention as a novel artificial light source for plant growth and functional component enhancement. We investigated the effects of LEP on whitening and antioxidant activities of the plant parts of perilla. Methods and Results: Previously germianted seeds of perilla were cultivated under different light conditions (fluoresce lamp, LED red, blue, white, green, and LEP) in a culture room for 2 months. Parts of perilla were harvested and extracted in 70% EtOH. The extracts were used to detect total phenolic contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and tyrosinase inhibition activity as indicators of biological activity. Biological activity was highest in seedlings grown under LEP. The total phenolic content was highest in the stems and the total flavonoid content was highest in the roots of perilla exposed to LEP. The DPPH and ABTS radical activity in all the parts of perilla exposed to LEP were higher by approximately three-fold compared to that in the control (fluoresce lamp). The reducing power values of perilla significantly increased after treatment with LEP. In addition, all the extract of perilla plants exposed to LEP promoted the tyrosinase inhibitory activity. These results suggest that LEP can be an important artificial light source for enhancement of biological activity. Conclusions: LEP could promote whitening and antioxidant activity of perilla.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.1-9
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• 2014

In this paper, we study inquiry tendency in informatics textbooks for middle school students. These textbooks were written in accordance with 2009 revised national curriculum, and were adopted in schools starting from 2013. Romey analysis was implemented to analyze inquiry tendency in six textbooks using four different criteria-text, data, activity, evaluation. The results showed that some textbooks displayed a low level of inquiry tendency, lacking participation from students and employing an authoritative tone. Among four factors, the 'activity' displayed the highest degree of inquiry tendency while the 'text' retained the lowest level of inquiry tendency. The Romey measures in some sections were zero, thereby indicating room for improvement.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2741-2746
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• 2013

The immobilization of enzyme is one of the key issues both in the field of enzymatic research and industrialization. In this work, we reported a facile method to immobilize Candida Antarctica lipase B (CALB) in alginate carrier. In the presence of calcium cation, the enzyme-alginate suspension could be cross-linked to form beads with porous structure at room temperature, and the enzyme CALB was dispersed in the beads. Activity of the enzyme-alginate composite was verified by enzymatic hydrolysis reaction of p-nitrophenol butyrate in aqueous phase. The effects of reaction parameters such as temperature, pH, embedding and lyophilized time on the reactive behavior were discussed. Reuse cycle experiments for the hydrolysis of p-nitrophenol butyrate demonstrated that activity of the enzyme-alginate composite was maintained without marked deactivation up to 6 repeated cycles.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.301-305
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• 2014

The Antioxidant activity screening identification of five kind compounds in Artemisiae annuae herba with the on-line screening high performance liquid chromatography (HPLC) $ABTS^+$ assay. The various experimental variables such as the extraction time (h) and extraction solvent composition (%) of dipping method were investigated efficiently extraction at the room temperature $25^{\circ}C$. The results, the highest yield of total extract amount (0.458 g, 15.250%) was obtained by dipping method with 100% water and extraction time to 3 h. And the on-line screening HPLC-$ABTS^+$ assay method was rapid and efficient to search for bioactivity from natural products.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.249-256
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• 2001

Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.600-606
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• 2010

The objective of this study was to develop functional rice coated with yacon roots extracts and to evaluate the antioxidant properties and physiological activity of rice coated with yacon extract. The washed rice was coated by spraying yacon extract at 10, 20, 30, and $40^{\circ}Brix$ and dried at room temperature. The moisture contents, color changes, antioxidant properties as total polyphenolics and DPPH radical scavenging activity and instrumental texture property and sensory evaluation change in the yacon root extracts coated rice and uncoated cooked rice were observed during 3 days of storage. Increasing the coating concentration was associated with lower color values(L value) and moisture contents. Total phenolics and DPPH radical scavenging properties generally increased in the cooked rice coated with yacon root extract more than the control (non-coated rice). However, D-20($20^{\circ}Brix$ of the yacon root concentration) resulted in better textural properties and sensory overall acceptability in cooked rice on 0 and 3 storage days. It was concluded that the optimum coating ration of rice and added functional yacon rice were $20^{\circ}Brix$ and 7% respectively, in proportion to the total weight of raw rice.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.55-65
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• 2007

This paper sought to investigate pupil size variability, pupil size parameters in terms of time domain and frequency domain, the autonomic activity change induced by posture change, degree of sleepiness and cognitive task (math task). With a specially designed pupil image acquisition system in the dark room, these three kinds of experiments were performed to induce a dominant state of sympathetic or parasympathetic activation. Electrocardiogram and pupil size were measured in all the experiments. Based on three experiments, we calculated heart rate variability. In the pupil size analysis, we calculated the mean and standard deviation of pupil size (in time domain), and proposed several frequency bands that exhibit different autonomic activation between different sessions. The results indicate that in terms of heart rate variability, posture change exhibited significant differences but not between sleepiness level, or between cognitive task. Pupil sizes differed only during the postures. And we found some frequency bands that correlated with autonomic activation in each experiment. While heart rate variability reflects posture change that need cardiac control, pupil size variability reflects not only posture induced autonomic activation but sleepiness and cognitive load, which is processed in the brain, in time and frequency domain parameter.