• The Korean Journal of Mycology
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• v.32 no.1
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• pp.31-38
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• 2004

An endophytic bacterial strain EB215 that was isolated from cucumber (Cucumis sativus) roots displayed a potent in vivo antifungal activity against Colletotrichum species. The strain was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, and 16S rDNA gene sequence. Optimal medium and incubation period for the production of antifungal substances by B. cepacia EB215 were nutrient broth (NB) and 3 days, respectively. An antifungal substance was isolated from the NB cultures of B. cepacia EB215 strain by centrifugation, n-hexane partitioning, silica gel column chromatography, preparative TLC, and in vitro bioassay. Its chemical structure was determined to be pyrrolnitrin by mass and NMR spectral analyses. Pyrrolnitrin showed potent disease control efficacy of more than 90% against pepper anthracnose (Colletotrichum coccodes), cucumber anthracnose (Colletotrichum orbiculare), rice blast (Magnaporthe grisea) and rice sheath blight (Corticium sasaki) even at a low concentration of $11.1\;{\mu}g/ml$. In addition, it effectively controlled the development of tomato gray mold (Botrytis cinerea) and wheat leaf rust (Puccinia recondita) at concentrations over $33.3\;{\mu}g/ml$. However, it had no antifungal activity against Phytophthora infestans on tomato plants. Further studies on the development of microbial fungicide using B. cepacia EB215 are in progress.

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.65-70
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• 2010

Medium-chain fatty acids (MCFA) are composed of 8-12 carbon atoms, and are found in coconut, cuphea, and palm kernel oil. MCFA were introduced into clinical nutrition in the 1950s for dietary treatment of malabsorption syndromes because of their rapid absorption and solubility. Recently, MCFA have been applied to Gastrointestinal Permeation Enhancement Technology (GIPET), which is one of the most important parts in drug delivery system in therapeutics. Therefore, to accumulate the MCFA in seed oil of rapeseed, much effort has been conducted by classical or molecular breeding. Laurate can be successfully accumulated up to 60 mol% in the seed oil of rapeseed by the expression of bay thioesterase (Uc FatB1) alone or crossed with a line over-expressing the coconut lysophosphatidic acid acyltransferase (LPAAT) under the control of a napin seed-storage protein promoter. Also, caprylate and caprate were obtained 7 mol% and 29 mol%, respectively, from plants over-expressing of the medium-chain specific thioesterase (Ch FatB2) alone or together with the chain-length-specific condensing enzyme (Ch KASIV). Despite the success of some research in utilizing parallel classical and molecular breeding to produce MCFA, commercially available seed oils have for the most part, not been realized. Recent research in the field of developing MCFA-enriched transgenic plants has established that there is no single rate-limiting step in the production of the target fatty acids. The purpose of this article is to review some of the recent progress in understanding the mechanism and regulation of MCFA production in seed oil of rapeseed.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.16-23
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• 2005

In order to develop a new microbial fungicide using endophytic bacteria for the control of anthracnoses occurring on various crops, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth medium, their antifungal activities were tested for in vivo antifungal activity against cucumber anthracnose caused by Colletotrichum orbiculare. As the results, liquid cultures of 28 strains showed potent antifungal activities more than $90\%$ against cucumber anthracnose. At 3-fold dilutions of liquid cultures, 18 strains inhibited the development of cucumber anthracnose of more than $70\%$. They were further tested for in vivo antifungal activity against red pepper anthracnose caused by C. coccodes and in vitro antifungal activity against C. acutatum, a fungal agent causing red pepper anthracnose. Among 18 strains, a bacterial strain EB215 isolated from cucumber roots displayed the most potent antifungal activity against Colletotrichum species. It was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, Biolog test and 16S rDNA gene sequence. It also controlled effectively the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), and tomato late blight (Phytophthora infestans). Studies on the characterization of antifungal substances produced by B. cepacia EB215 are in progress.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.611-622
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• 2006

Fatty acid compositions and physicochemical properties of feta cheese made from bovine milk were studied. Nutritional compositions of feta cheese were fat 22.79%, protein 10.57% with moisture content of 59.87%. The log cfu/g of lactic acid bacteria in bovine feta cheese decreased from 10.25 to 7.95 and pH also changed from pH 6.22 to pH 5.55 during storage at 4℃ for 14 d aging. The color of feta cheese turned into more whitish (L-value, 100.1) with a red (a-value, 4.6) and gray (b-value,－4.1) color after 14day's aging. For the texture profile analysis of bovine feta cheese, resilience was increased significantly (p<0.01) throughout the aging periods and adhesiveness was rapidly increased right after progressing of aging at both temperatures, but no difference was found between the aging periods. Hardness, fracturability, gumminess and chewiness were gradually increased at 0℃, but no statistical significances were found. Springiness and cohesiveness were not changed at both temperatures. In organoleptic evaluations, organoleptic intensities in sweetness, milky taste and saltiness were significantly enhanced over those of the control cheese at the level of p<0.01, and masticatory texture at p<0.05 with the progress of aging to 14d. Organoleptic preferences were significantly (p<0.01) enhanced except smell, color, mouth feel, and masticatory texture with the aging. In the fatty acid compositions of feta cheese analyzed by gas chromatography, the content of SFA (52.61%) was slight higher than that of USFA (47.39%) composed with MUFA (28.98%) and PUFA (18.41%). Among the nutritionally important fatty acids; ω6 (9.27%) and ω3 (0.55%) fatty acids, CLA (0.12%), arachidonic acid (0.19%) and DHA (0.12%) were also found in bovine feta cheese.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.1
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• pp.43-52
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• 2017

EtOAc fractions of Magnolia obovata (M. obovata) Bark extracts were studied for the potential ingredient as a safe and effective whitening cosmetic material. The concentration of active substances honokiol was determined by HPLC. In vitro, the fractions reduced the extracellular and intracellular melanin contents in B16F10 cells in dose dependently and inhibited extracellular melanin secretion ($IC_{50}=11.05{\mu}g/mL$). The $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 60% to the amount of extracullular melanin. Also, the $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 59% to the amount of intracullular melanin ($IC_{50}=10.85{\mu}g/mL$). The $IC_{50}$ value of ${\alpha}-arbutin$ used as a positive control was $59.99{\mu}g/mL$. So, EtOAc fractions of M. obovata Bark extracts showed whitening effect when compared with the non-treatment group. In case of in vivo study, Cosmetic cream with EtOAc fractions of M. obovata Bark extracts was approved by Ethics committee of KDRI (IRB number: KDRI-IRB-1537). As a result in progress for skin sensitization as well as assessment of skin irritation through repeated patch test, skin allergens was identified as non sensitizing agents. Also, cosmetic cream with EtOAc fractions of M. obovata Bark extracts showed significant topical whitening effect and reliable skin safety when compared with the non-treatment group. In conclusion, EtOAc fractions of M. obovata Bark extracts may be a useful cosmetic ingredient for effective skin whitening.

• Progress in Medical Physics
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• v.26 no.3
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• pp.119-126
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• 2015

The purpose of this study is to analyze motion-induced dose error generated by each tumor motion parameters of irregular tumor motion in helical tomotherapy. To understand the effect of the irregular tumor motion, a simple analytical model was simulated. Moving cases that has tumor motion were divided into a slightly irregular tumor motion case, a large irregular tumor motion case and a patient case. The slightly irregular tumor motion case was simulated with a variability of 10% in the tumor motion parameters of amplitude (amplitude case), period (period case), and baseline (baseline case), while the large irregular tumor motion case was simulated with a variability of 40%. In the phase case, the initial phase of the tumor motion was divided into end inhale, mid exhale, end exhale, and mid inhale; the simulated dose profiles for each case were compared. The patient case was also investigated to verify the motion-induced dose error in 'clinical-like' conditions. According to the simulation process, the dose profile was calculated. The moving case was compared with the static case that has no tumor motion. In the amplitude, period, baseline cases, the results show that the motion-induced dose error in the large irregular tumor motion case was larger than that in the slightly irregular tumor motion case or regular tumor motion case. Because the offset effect was inversely proportion to irregularity of tumor motion, offset effect was smaller in the large irregular tumor motion case than the slightly irregular tumor motion case or regular tumor motion case. In the phase case, the larger dose discrepancy was observed in the irregular tumor motion case than regular tumor motion case. A larger motion-induced dose error was also observed in the patient case than in the regular tumor motion case. This study analyzed motion-induced dose error as a function of each tumor motion parameters of irregular tumor motion during helical tomotherapy. The analysis showed that variability control of irregular tumor motion is important. We believe that the variability of irregular tumor motion can be reduced by using abdominal compression and respiratory training.

• Progress in Medical Physics
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• v.18 no.1
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• pp.27-34
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• 2007

Respiration sating radiotherapy technique developed In consideration of the movement of body surface and Internal organs during respiration, is categorized into the method of analyzing the respiratory volume for data processing and that of keeping track of fiducial landmark or dermatologic markers based on radiography. However, since these methods require high-priced equipments for treatment and are used for the specific radiotherapy. Therefore, we should develop new essential method whilst ruling out the possible problems. This study alms to obtain body surface motion by using the couch based computer-controlled motion phantom (CBMP) and US sensor, and to develop respiration gating techniques that can adjust patients' beds by using opposite values of the data obtained. The CBMP made to measure body surface motion is composed of a BS II microprocessor, sensor, host computer and stopping motor etc. And the program to control and operate It was developed. After the CBMP was adjusted by entering random movement data, and the phantom movements were acquired using the sensors, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using a rabbit, the real-time respiration gating techniques were drawn by operating the phantom with the opposite values of the data. The result of analysing the acquisition-correction delay time for the data value shows that the data value coincided within 1% and that the acquistition-correction delay time was obtained real-time $(2.34{\times}10^{-4}sec)$. And the movement was the maximum movement was 6 mm In Z direction, In which the respiratory cycle was 2.9 seconds. This study successfully confirms the clinical application possibility of respiration gating techniques by using a CBWP and sensor.

• Progress in Medical Physics
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• v.20 no.1
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• pp.21-29
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• 2009

Breast cancer is the most common form of cancer among korean woman. Therefore, the early detection activities of breast cancer such as breast self-examinations, clinical breast examinations, mammography are important. A yearly mammography examination has been recommended for women aged 40 and older for the early detection of breast cancer in asymptomatic periods. However, the glandular tissue of breast is the most radiation-sensitive tissue, and the determination of average glandular dose (AGD) forms an important part of the quality control of the mammographic systems. Because of the difficulty of estimating AGD directly, it is often estimated from the measurements of the incident air kerma and by applying the appropriate conversion factors. The primary objective of this study was to standardize the method of measuring AGD. The secondary objective was to evaluate the relationships between AGD per various composition and thickness of the breast using Monte Carlo simulations. As a result, we standardized the method of measuring AGD according to International Atomic Energy Agency (IAEA) guidelines (CoP: an international code of practice). Overall, AGD for mammographic practice in Korea was less than 3.0 mGy recommended by the Korea Food and Drug Adminstration (KFDA) protocol, and Korean Institute for Accreditation of Medical Image (KIAMI). The measured and simulated AGD for a given condition were calculated as 1.7 and 1.6 mGy, respectively. For the AGDs obtained, there was no significant difference between them. The simulated AGD was dependent on the fraction of glandular tissue of the breast. The AGD increases with increasing of the breast glandularity due to increasing absorption of low energy photons. The AGD also increases as a function of breast thickness. In conclusion, the results of this study could be used as a baseline to establish a reference level of radiation dose in mammography.

• Journal of The Korean Association For Science Education
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• v.32 no.5
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• pp.903-927
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• 2012

The study aimed to analyze middle school students construction of physics inquiry problems for open inquiry from the viewpoint of variable isolation and clarification, and investigate students' difficulties during the processes of variable isolation and clarification to get implications for teaching and learning strategies for small group open inquiry activities which have been included in the 2007 national curriculum. The participants were 4 students who had attended an outreach program for the science gifted run by a university institution located in Seoul area. They performed an open inquiry on egg drop for 13 lessons for 30 hours. Level descriptions for variable isolation and clarification have been developed and applied to analyze students' inquiry problems and variables included by the problems. Students iterated inquiry processed 5 times and the inquiry problem showed progress gradually. Dependent variables have been isolated ahead and the levels of variable isolation and clarification showed higher than the independent variables. Many kinds of independent variables isolated extensively and the independent variables and control variables have been mingled. One of the reasons why students had some difficulties in isolation of independent variables could be the absence of theoretical models. The realities of school lab could restrict the variable isolation and clarification as well as topic selections. Some sensory or extensive variables such as broken eggs and drop height seem to be salient to be focused on as core variables. Lack of background knowledges could be one of the reasons for students' difficulties in variable clarification, such as theoretical definitions and operational definitions. As a result of lacking background knowledges, students could not construct theoretical models even though they could isolate and clarify variables as scientific lexical definitions. Some perceptions of inquiry as trial and error or reckless establishment of causal relations between variables could be accounted as one reason.

• The Korean Journal of Elementary Counseling
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• v.8 no.1
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• pp.33-50
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• 2009

The purpose of this study was to develop a PBL-based career education program and to examine its effectiveness on school children's career maturity. It's specifically meant to prepare a career education program to assist students to get an accurate grip on their aptitude, interest and personality and explore various sorts of occupations in the course of solving authentic and contextual career-related problems. After children's developmental characteristics and needs were analyzed, task analysis was implemented, and the objectives were defined. And then the core of the program, PBL problems were developed, and the validity of the problems were verified Evaluation plans and tools were prepared to assess children's problem-solving process and presentation, and an online learning space was designed. The program that consisted of 10-minute 21 sessions was provided to fifth-grade elementary schoolers for eight weeks. The findings of the study were as follows: The experimental group that participated in the PBL-based career education program showed a more significant improvement than the control group that didn't in career attitude and three career attitude subfactors involving planness, disposition and compromise. And the former made a more significant progress than the latter in career ability and its subfactors including vocational comprehension, self-understanding and decision-making skills as well. As a result of making a content analysis to make up for the survey, the students reported that they were able to get an objective understanding of themselves and acquire diverse and profound knowledge on work and the business world in the middle of solving the given PBL problems related to different areas in group and giving a presentation. In conclusion, a PBL based career education program developed by this researcher encouraged the students to have an objective self-understanding, to have a dynamic interactive discussion with their group members. Therefore the program had a positive impact on boosting the career attitude and career ability of the elementary schoolers. The findings suggested that in the field of elementary career education, autonomous learning attitude and subjecthood are the crucial factors to stimulate school children to explore and create their own future.