• Horticultural Science & Technology
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• v.18 no.6
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• pp.834-838
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• 2000

As an endeavor to establish a micropropagation system for Epimedium koreanum Nakai., this study was carried out to define methods to disinfect its explants and media for callus induction, proliferation and plant regeneration. The lowest infection rates by fungi or bacteria on apical and axillary bud explants of rhizome were observed when they were immerged in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 30 min, but leaf explants were seldom infected with fungi or bacteria by this disinfectant method. The highest rate of plantlet formation was obtained from the explants disinfected in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 60 min for tip buds and in 0.1 % $AgNO_3$ solution for 30 min for axillary buds of rhizome. Induction rate of callus was the highest from the explants disinfectd in 0.3% NaOCl solution for 20 min after soaked in 0.2% $AgNO_3$ solution for 15 min. Callus growth was proper in a modified 1/2 MS medium including half strength of $NH_4NO_3$ with $0.02-0.2mg{\cdot}L^{-1}$ BA and $2.0mg{\cdot}L^{-1}$ NAA. Low rate of plantlet regeneration was obtained in 1/2 UM or 1/2 White medium with $2.0mg{\cdot}L^{-1}$ BA and $0.2mg{\cdot}L^{-1}$ AA.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.274-283
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• 2020

This study focused on the in vitro investigation of antioxidant and anti-diabetic activities, along with neuroprotection against high glucose-induced cytotoxicity, in order to evaluate the physiological effects of Zanthoxylum piperitum and Zanthoxylum schinifolium. The highest total phenolic content was measured in the 40% ethanolic extracts of Zanthoxylum piperitum (EZP) and Zanthoxylum schinifolium (EZS). The in vitro EZP antioxidant activity showed a relatively higher ABTS/DPPH radical scavenging activity and malondialdehyde inhibitory effect than that of EZS. The EZP inhibited carbohydrate hydrolysis (α-glucosidase and α-amylase) more efficiently than EZS in anti-diabetic tests. However, EZS showed a more efficient inhibition of advanced glycation end-products formation than EZP. In addition, both EZP and EZS effectively protected human-derived neuronal cells from high glucose-induced cytotoxicity. Finally, the physiological compounds were analyzed using UPLC IMS-QTOF/MS^E, and the main EZP (quercetin-3-O-glucoside and 3-caffeoylquinic acid) and EZS (5-caffeoylquinic acid) compounds were identified as phenolic compounds.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.301-305
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• 2012

This study was conducted to investigate the microbiological contamination levels in rice cakes and rice flour due to climate change in three areas classified to their temperature and precipitation. We investigated the contamination levels of total aerobic bacteria, coliforms, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Clostridium perfringens of rice flour and 3 rice cakes such as Garaetteok, Sirutteok and Gyeongdan. Contamination levels of total aerobic bacteria in rice flour were 4.9 log CFU/g. In a total of 70 rice flour, yeasts & molds and coliforms were detected in 42 and 52 samples at the levels of 43 CFU/g and 1.29 log CFU/g, respectively. S. aureus were detected in only 1 rice flour (1.66 log CFU/g) out of 70. In an investigation of contamination levels in rice cakes, the population of total aerobic bacteria were highest in Gyeongdan (5.18 log CFU/g) and coliforms were highest in Gareattock (2.93 log CFU/g). There was no detection of E. coli and B. cereus except for only 1 Gareattock (1.20 log CFU/g). There were no differences of contamination levels among the three areas. If constant monitoring of rice cakes and rice flour is conducted on the basis of this study, it is expected to be able to analyze the change of contamination levels in rice cakes and rice flour due to climate change.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.277-284
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• 2012

The objective of this study was to investigate and evaluate microbial contamination levels of leafy greens (perilla leaf and lettuce) and its distributing conditions at different seasons (Feb, May, Aug, and Nov of the year 2011) in order to provide insight into any potential health hazards associated with consumption of these commodities. Leafy greens were collected from a farm located in Geumsan, Chungnam and wholesale markets (WM) and traditional markets (TM) located in Suwon. At the same time, temperature and relative humidity fluctuations experienced by the leafy greens during distribution from the farm to the distribution center were measured by a data logger. The contamination levels of perilla leaf and lettuce were determined by analyzing total plate count. Coliform groups, Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were determined. The contamination levels of total aerobic bacteria, coliform groups and B. cereus in both vegetables sampled during May and August found to be higher than those sampled during February and November. E. coli O157:H7, Salmonella spp., L. monocytogenes were not detected in the vegetables analyzed in this study. There were no significant trends between samples at WM and TM in the contamination levels. Relative humidity of vegetables distributed from the farm to the distribution center showed over 90% during distribution regardless of measured seasons. In the case of background microflora on leafy greens, the density was significantly increased at 20, 30 and $37^{\circ}C$ during storage of 24h. E. coli O157:H7 and B. cereus inoculated on the leaves also showed similar increases in the storage tests. The microbial contamination levels determined in this study may be used as the fundamental data for microbial risk assessment.

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.485-510
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• 2011

This study aimed to analyze the appropriateness of chemistry teaching-learning programs for the gifted in science in middle school gifted classes and to propose improvements. For this study, 5 chemistry teaching-learning 4-6 hour programs developed for science gifted classes by Korea Education Development Institute (KEDI) and 3 chemistry teaching-learning programs developed for science gifted classes by three middle schools in K province were selected. A standard model for gifted education programs was used as tool for analyzing the program targets, program contents, teaching-learning methods, and assessment items. The results showed that all chemistry teaching-learning programs for the gifted in science presented well attainable objectives in the program targets. However, most program targets did not offer differentiated objectives from the general education. Program contents of KEDI stresses intensified education, and also presented a high ratio of sub-elements of creativity, which can enhance gifted creativity. On the other hand, program contents developed by three middle schools focused on acceleration in advancement, and presented low ratio of creativity sub-elements, which could be insufficient in enhancing gifted creativity. Differentiated and personalized, integrated science and interscience, updated research contents were hardly found in programs developed by KEDI and three middle schools. However, teaching-learning methods were composed to fit the learning objectives in the teaching process and the procedures, and were made to self-directed learning. There were no assessment for the feedback after class. Therefore, teaching-learning programs for the gifted in science should be developed further in order to fulfill the objectives of gifted education and gifted characteristics. Also, it is necessary to construct infrastructure to carry out the developed teaching-learning programs.

• Journal of The Korean Association For Science Education
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• v.19 no.1
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• pp.41-61
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• 1999

In this study I defined the direction Integrated Science Education(ISE) should take. So that I groped for the direction ISE should take in the inherent nature of science and education, analyzing their respective validity from philosophical and psychological angles. Based upon these researches, I formulated the three directions for ISE to take; knowledge-centered, social problem-centered, and individual interest-centered. The results of this thesis may be summed up as follows: 1. The knowledge-centered ISE that thinks the inherent nature of science is in the scientific knowledge is based upon Hirst's integrated logic which is built on discipline-centered educational viewpoint. Now, the focus of interdisciplinary integration consists in clarifying the meanings of knowledge and the logical relations between one knowledge and another according to the respective form of exploration. The knowledge-centered ISE, therefore, was analyzed to find its justification in the educational philosophy of idealism, realism, neo-scholasticism; in the educational theories of essentialism, behaviorism, perennial ism; in the scientific philosophy of empiricism. positivism; in the educational psychology of developmental psychology and constructivism. 2. The social problem-centered ISE that thinks the inherent nature of science is the process of social concord is based upon Dewey's integrated logic which is built on experience-centered educational viewpoint. Now, the focus of interdisciplinary integration consists in the methodological aspect facilitating the process of experience. The social problem-centered ISE, therefore, was analyzed to find its theoretical justification in the educational philosophy of pragmatism; in the educational theory of progressivism; in the scientific philosophy of relativism and rationalism; and in the educational psychology of developmental psychology and constructivism. 3. The individual interest-centered ISE is based upon Patterson's integrated logic which is built on human-centered educational viewpoint. The focus of education here is self-realization. Therefore, rather than provide in learning conditions from outside, one is made to choose them oneself and the process of satisfying one's motive is emphasized. The individual interest-centered ISE, therefore, was analyzed to find its theoretical justification in the educational philosophy of existentialism; in the educational theory of humanism; in the scientific philosophy of relativism; and in Gestalt psychology.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.272-279
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• 2015

This study was conducted to provide baseline data which could suggest a direction of role based efficient integrated clinical education by avoiding duplicate of contents through analyzing clinical courses. Among the 7 clinical courses, orthodontics and periodontology were the most published subjects which were published in 5 kinds of books and dental materials was the least published subject which was published in 2 kinds of books on investigation of overlapping contents based on titles that appeared on chapters and verses of all textbooks for clinical courses. Dental implant was covered in 4 subjects such as oral maxillofacial surgery, prosthodontics, periodontology and dental materials which was the most number. Other overlapping contents were restoration treatment, occlusion and malocclusion, temporomandibular joint diseases, anesthesia sedation, tooth trauma, systemic disease and dental treatment, dental casting, isolation techniques, tooth bleaching, pulp protection, gingivitis periodontitis, tooth development, etc. Reviews of textbooks of clinical courses should be conducted in a detailed manner by systematic, various studies in order to improve quality of the textbooks.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.93-104
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• 2015

Purpose: This study aimed to analyze the research trends of Ophthalmic Optic by targeting the papers published in the Journal of Korean Ophthalmic Optics Society and serve it as a basis for future researches. Methods: This study was conducted through a statistical analysis of the general characteristics, researcher characteristics, research characteristics and the research trends from total 990 papers, from the first issue to the last issue in 2014, published in the Journal of Korean Ophthalmic Optics Society. Results: Most common number of the authors of the published papers were two or three, respectively 26.8%. Most of the lead authors belong to the schools in Jeolla-do province (31.3%). Most of the educational system of which lead authors belong to is four-year-course system (43.0%). Most common research methods were optometric tests (40.9%). The most common subjects of researches are about the field of optometry (29.8%). The study shows that there were significant differences in the research methods depending on the school systems of the universities to which the lead authors belong (p=0.000). There also were significant differences in the school systems of the universities to which the lead authors belong, and research methods depending on the research subjects (p=0.000). There were meaningful differences according to the period divisions (1996 to 2004 and 2005 to 2014), i.e. the number of authors has been growing, and it is the same case for the number of the authors who belong to four-year-course universities (p=0.000). The number of papers on optometry and contact lenses have increase. The benefits of the research funds have also increased (p<0.005). In addition, the number of the lead authors in the Seoul and Chungcheong province have increased (p=0.000). Conclusions: For the development of the Ophthalmic Optics, it is necessary to broaden the stratum of researchers and deal with various research topics, And joint efforts between eyewear industry and academia and international cooperations are needed.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.31-37
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• 2000

This study was designed to identify the ultrastructural changes of mouse endometrium during peri-implantation period and obtain the fundamental information for the establishment of 3-dimensional culture system of mouse endometrial cells in vitro. The used female ICR mice ($6{\sim}8$ wks) were conducted on pregnant. The biopsies were obtained from whole uterus at cycle day 1 (D1) and day 5 (D5) after hCG injection and mating. The biopsies materials were fixed 2.5% glutaraldehyde and 1% osmium tetroxide. Subsequently, for observation using light and transmission electron microscopy (LM and TEM), they were dehydrated and embedded in Epon and the embedded biopsies were sectioned and stained. For scanning electron microscopy (SEM), the fixed specimens were dehydrated, dried and coated with gold. 1) For LM, the biopsied materials at D5 (late secretory phase) were appeared the extended stromal layer by increased connective tissues and the fully developed endometrial glands and vessels compared with D1 (early secretory phase). 2) For TEM, the mouse endometrium was consisted of 3-layers, a simple polarized columnar epithelial cells, basement membrane and stromal cells. At D5, the distribution of microvilli, endoplasmic reticulum, Golgi body, lipid and glycogen deposits, secretory granules and surface area of basement membrane were increased. 3) For SEM, the degree of folding and microvilli of surface of mouse epithelial cells was became more and more according to the process of secretory phase, and at D5, implantation time of mouse, the appearance of pinopodes as a specific marker of uterine receptivity was found. The uterine pinopodes of mouse were found in narrow sites at the luminal surface, irregularity and appeared the different stages in the same sample. Therefore, these results indicated that the mouse endometrium was experienced dramatic morphological changes during peri-implantation period.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.67-74
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• 2000

Objective: This study was conducted to investigate the effect of vitrification on the implantation and the pregnancy of human blastocysts. Method: The transfer of the frozen-thawed blastocysts by the slow freezing or vitrification was performed between January 1998 and July 1999. The zygotes derives from IVF were cocultured with cumulus cells in YS medium containing 20% hFF for 5days. Two or three of the best balstocysts produced on day 5 were transferred into the uterus, and then supernumerary blastocysts were randomly divided into two groups. One was frozen by slow freezing and the other was frozen by vitrification method. The slow freezing procedure was performed in two steps (5% glycerol and 9% glycerol + 0.2 M sucrose for 10 min, respectively) using programmed freezer ($-2^{\circ}C$/min to $-7^{\circ}C$, manual seeding at $-7^{\circ}C$, $-0.3^{\circ}C$/min to $-38^{\circ}C$ and plunged into $LN_{2}$). The blastocysts frozen by slow freezing were thawed at $36^{\circ}C$ then removed glycerol in 7 steps. The vitrification procedure was performed in three steps (10% glycerol for 5 min, 10% glycerol + 20% ethylene glycol for 5 min, 25% glycerol + 25% ethylene glycol and directly $LN_{2}$ within 1 min). The blastocysts frozen by vitrification were thawed at $20^{\circ}C$ water then removed cryoprotectant in 3 steps. In each group, thawed blastocysts were cocultured with cumulus cells in YS medium containing 20% hFF for 18h and transferred into the uterus. The implantation rate was evaluated per transferred blastocysts and the pregnancy rate was evaluated per transfers. Results: The survival rate of vitrified group (74.5%) was higher than slow freezing group (68.0%), but not significant. When 98 thawed blastocysts of vitrification were transferred in 40 cycles, 19 pregnancies (clinical pregnancy rate; 47.5%) were established. One miscarriage occurred in the eighth week of pregnancy (ongoing pregnancy rate; 45.0%). 7 pregnancies were ongoing, 11 pregnancies went to term, and 16 healthy infants were born. The Implantation rate was 31.6%. These results were higher than those obtained by the slow freezing (clinical pregnancy rate; 40.3%, ongoing pregnancy rate; 32.5% and implantation rate; 25.3%), but not significant. Conclusion: Vitrification is a simple, quick and economical method when compared to slow freezing. It will be chosen as a good method of human embryo freezing in IVF-ET programs.