• Clinical and Experimental Reproductive Medicine
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• 제31권1호
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• pp.67-74
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• 2004

Objective: This study was to examine in vitro neural cell differentiation pattern of the genetically modified human embryonic stem cells expressing tyrosine hydroxylase (TH). Materials and Methods: Human embryonic stem (hES, MB03) cell was transfected with cDNAs cording for TH. Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA, embryoid bodies (EB, for 4 days) derived from TH#2/MB03 cells were exposed to RA ($10^{-6}M$)/AA ($5{\times}10^{-2}mM$) for 4 days, and were allowed to differentiate in N2 medium for 7, 14 or 21 days. Exp. II) When b-FGF was used, neuronal precursor cells were expanded at the presence of b-FGF (10 ng/ml) for 6 days followed by a final differentiation in N2 medium for 7, 14 or 21 days. Neuron differentiation was examined by indirect immunocytochemistry using neuron markers (NF160 & NF200). Results: After 7 days in N2 medium, approximately 80% and 20% of the RA or b-FGF induced Th#2/MB03 cells were immunoreactive to anti-NF160 and anti-NF200 antibodies, respectively. As differentiation continued, NF200 in RA treated cells significantly increased to 73.0% on 14 days compared to that in b-FGF treated cells (53.0%, p<0.05), while the proportion of cells expressing NF160 was similarly decreased between two groups. However, throughout the differentiation, expression of TH was maintained ($\sim$90%). HPLC analyses indicated the increased levels of L-DOPA in RA treated genetically modified hES cells with longer differentiation time. Conclusion: These results suggested that a genetically modified hES cells (TH#2/MB03) could be efficiently differentiated in vitro into mature neurons by RA induction method.

• Imaging Science in Dentistry
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• 제50권1호
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• pp.15-22
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• 2020

Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliability of 2-dimensional(2D) photography and 3-dimensional(3D) soft tissue imaging. Materials and Methods: Facial images of 50 volunteers(25 males, 25 females) were captured with a Nikon D800 2D camera (Nikon Corporation, Tokyo, Japan), 3D stereophotogrammetry (SPG), and laser scanning (LS). All subjects were imaged in a relaxed, closed-mouth position with a normal smile. The 2D images were then exported to Mirror^® Software (Canfield Scientific, Inc, NJ, USA) and the 3D images into Proplan CMF^® software (version 2.1, Materialise HQ, Leuven, Belgium) for further evaluation. For an objective evaluation, 2 observers identified soft tissue landmarks and performed linear measurements on subjects' faces (direct measurements) and both linear and angular measurements on all images(indirect measurements). For a qualitative analysis, 10 dental observers and an expert in facial imaging (subjective gold standard) completed a questionnaire regarding facial characteristics. The reliability of the quantitative data was evaluated using intraclass correlation coefficients, whereas the Fleiss kappa was calculated for qualitative data. Results: Linear and angular measurements carried out on 2D and 3D images showed excellent inter-observer and intra-observer reliability. The 2D photographs displayed the highest combined total error for linear measurements. SPG performed better than LS, with borderline significance (P=0.052). The qualitative assessment showed no significant differences among the 2D and 3D imaging modalities. Conclusion: SPG was found to a reliable and accurate tool for the morphological evaluation of soft tissue in comparison to 2D imaging and laser scanning.

• 한국작물학회지
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• 제37권3호
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• pp.288-298
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• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

• 한국농공학회논문집
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• 제62권2호
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• pp.97-109
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• 2020

Drought is one of the most influential disasters in sustainable agriculture and food security of nations. In order to preemptively respond to agricultural droughts, vulnerability assessments were conducted to predict the possibility of drought in the region, the degree of direct or indirect damage, and the ability to cope with the damage. Information on agricultural drought vulnerability status of different regions is extremely useful for implementation of long term drought management measures. The purpose of this study is to develop and implement a quantitative approach for measuring agricultural drought vulnerability at sub-district level based on agricultural water and reservoirs. To assess the vulnerability in a quantitative manner and also to deal with different physical and socioeconomic data on the occurrence of agricultural drought, we selected the appropriate factors for the assessment of agricultural drought vulnerability through preceding studies, and analyzed the meteorological and agricultural reservoir data from 2015 to 2018. Each item was weighted using AHP (Analytic Hierarchy Process) analysis and evaluated through the agricultural drought vulnerability estimation. The entire national vulnerability assessments showed that Ganghwa, Naju, and Damyang were the most vulnerable to agricultural droughts. As a result of analyzing spatial expression, Gyeongsang-do is relatively more vulnerable to drought than Gangwon-do and Gyeonggi-do. The results revealed that the methodology and evaluation items achieved good performance in drought response. In addition, vulnerability assessments based on agricultural reservoir are expected to contribute supporting effective drought decisions in the field of agricultural water management.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.4086-4092
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• 2013

Mycosporine-like 아미노산(MAAs)은 UV 흡수물질이며, 다양한 해양생물들은 MAAs의 합성과 축적을 통하여 환경 자외선의 직 간접적인 영향을 감소시키는 기능을 진화시켜 왔다. 이 연구에서 우리는 radiofrequency(RF) 발생장치를 제작하였고, 이를 미세조류 배양에 적용하였다. $0.35{\pm}0.05$ mHz의 RF를 Chlamydomonas sp. 배양기에 공급하였고, 정해진 시간(0, 0.5, 1 및 2 시간)에 시료를 채취하였다. MAAs 생합성 관련 유전자인 dehydroquinate synthase homolog (DHQS-like)와 nonribosomal peptide synthetase homolog (NRPS-like) 유전자를 Chlamydomonas sp.로부터 클로닝하였고, RF 노출에 대한 유전자 발현을 qRT-PCR을 이용하여 분석하였다. 연구결과 RF에 노출된 Chlamydomonas sp.의 DHQS-like와 NRPS-like 유전자의 발현은 노출 1시간에 각각 1.46 배 및 1.19 배 증가하였다. 이러한 결과는 DHQS-like와 NRPS-like 유전자가 Chlaydomonas sp.의 MAAs 생합성을 진단할 수 있는 좋은 바이오마커 후보가 될 수 있음을 의미한다.

• 만화애니메이션 연구
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• 통권10호
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• pp.1-16
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• 2006

본 논문에서는 한국 신문네칸만화에 있어서 언어유희의 기법과 그 기능을 분석하였다. 우리나라 신문네칸만화는 생활만화로 정착한 서구의 네칸만화와 달리 시사만화로 발달하면서 정보전달의 기능이 중시되는 미디어적 특성을 갖게 되었다. 이 때문에 네칸만화는 무엇보다 정확하고 함축적인 언어의 힘을 크게 필요로 하는 장르로 자리잡게 되었다. 또한 한국 네칸만화는 그 성장과정에서 국가권력의 과도한 통제로 인해 의미전달에 있어서 직접성이 강한이미지 기법보다 우회적 표현이 가능한 언어 기법의 모색에 천착하게 되었다. 그 결과 우리나라 네칸만화텍스트는 ‘수사법의 보고(寶庫)’라고 할 만큼 다채로운 언어운용의 방법들을 보여준다. 본 논문에서는 네칸만화에 있어서 만화의 주된 효과인 재미와 감동 창출의 동력이며 창작의 원리로 작동해온 수사법들 중에서 언어운용의 방법들을 단적으로 보여주는 언어유희의 기법을 살펴고자 한다. ‘촌철살인()의 미학’으로 요약되는 우리나라 네칸만화에 나타난 언어라는 요소의 기능과 가치에 대한 고찰은 만화예술에 있어서 언어가 갖는 중요성을 환기시킨다.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.408-417
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• 2017

본 연구는 여가스포츠에 참여중인 만 60세 이상 노인들을 대상으로 신체적 자기효능감, 우울감, 자아통합감의 구조적 관계를 규명하는데 그 목적이 있다. 또한 최근 자아통합감에 영향을 미치는 변인은 다차원적으로 제시되고 있으므로 변인들의 인과관계를 통합적 관점에서 살펴보는 것이 매우 중요하다. 이상의 목적을 달성하기 위하여 노인기관에서 여가스포츠 프로그램에 참여중인 노인 427명을 연구대상으로 설정하였으며, 구조방정식 모형분석을 실시하였다. 이를 위해 각 변인을 대상으로 확인적 요인분석과 신뢰도 분석을 실시하였으며, 직접효과, 간접효과, 총효과 등을 추정하였다. 모형 적합도는 TLI, CFI, RMSEA를 참고하였으며, 측정모형의 적합도와 연구모형의 적합도 모두 그 기준을 만족하였다. 연구가설 검증결과 첫째, 설문지에 관한 타당도와 신뢰도 검증 결과 신체적 자기효능감, 우울감, 자아통합감 변인 모두 적합한 것으로 나타났다. 둘째, 인지된 신체능력은 우울감, 현재생활만족, 지혜로운 삶, 생에 대한 태도에 긍정적인 영향을 미치는 것으로 나타났으며 신체적 자기표현 자신감은 현재생활만족, 생에 대한 태도에는 긍정적인, 지나온 삶 수용에는 부정적인 영향을 미치는 것으로 나타났다. 마지막으로 우울감은 현재생활만족에 부정적인 영향을 미치는 것으로 나타났다. 이상에서 나타난 결과는 노인들의 신체적 자기효능감, 우울감, 자아통합감의 통합적 관계를 규명하였다는 것에 의미가 있다.

• 디지털융복합연구
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• 제15권10호
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• pp.429-436
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• 2017

유가공산업 순환생태계 내의 다양한 이해관계자들이 참여한 디자인 사고 기반의 협력적 워크숍(Design Thinking Workshop)은 '창의기제'로서 디자인 작업 방식을 바탕으로 직면 문제에 대한 구성원 간 공감대와 집단지성의 발현, 협업과 소통방식의 전환, 조직의 업무처리에 있어 실천적 프로토타이핑 문화 확산을 독려하는 새로운 문제 혁신 패러다임을 보여준다. '문제에 대한 접근', '문제의 재정의', '경험기반 미래비전 설계'의 3단계로 추진된 이 워크숍은 참여자들 스스로 사료공급업체와 축산농가주 간 사료주문의 정확도, 사료의 정시주문, 사료공급의 비용절감 측면에서 진짜 문제를 재정의 하고 새로운 대안과 확장된 비즈니스 영역을 제시한다. 이 워크숍에서 제안된 결과는 축산사료의 수급율과 품질 향상뿐만 아니라 산업의 직 간접적 이해관계자들에게 문제에 접근하는 방식과 그 해결점을 모색하는 창의적인 사고체계를 제시했다는 점에서 비즈니스 혁신에 있어 디자인 사고의 유용성을 시사한다.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.497-517
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• 1995

The cells associated with normal defense mechanism in inflammation release free oxygen radicals, hydroxy radicals, and various protease, all of which can damage the surrounding cells(fibroblasts) and matrix molecules(collagen). The objective of this study was to evaluate the effects of "scavenger" enzyme, superoxide dismutase(SOD). to periodontal ligament (PDL) cells. Human PDL cells were cultured from the teeth extracted for non-periodontal reason. Cultured PDL cells in vitro were treated with SOD and LPS according to dosage and culture times. Cellular activity was exaimed by Microtitration(MTT) assay. The quantitative expression of cellular proliferation by proliferating cell nuclear antigen(PCNA), collagen type I and fibronectin by indirect immunocytochemically stain in PDL cells were done. The results were as follows: 1. As only SOD treated group at 2 and 3 days, PDL cell activity was significantly increased at more than 150U(P<0.05). 2. When LPS(0.5, $5{\mu}g/m{\ell}$) and SOD(more than 150U) were added together, it was significantly increased than LPS only treated and control groups at 2 days(P<0.05). 3. When LPS($5{\mu}g/m{\ell}$) and SOD(150, 300U) were added together, PCNA index was significantly increased than LPS only treated and control groups at 2 and 3 days(P<0.05). 4. When LPS($5{\mu}g/m{\ell}$) and SOD(150U) were added together, collagen type I was significantly increased than LPS only treated and control groups at 3 days(P<0.05). 5.When LPS($5{\mu}g/m{\ell}$) and SOD(300U) were added together, fibronectin was significantly increased than LPS only treated and control groups at 3 days(P<0.05). On the above the results, the SOD in association with collagen type I, fibonectin, and PCNA may afford biological protection to oxy-radicals that were typically liberated during normal inflammatory response. Thus, the exogenous application of SOD may be effective in sthe treatment of the localized breakdown associated with chronic periodontal disease.

• 한국학교수학회논문집
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• 제17권4호
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• pp.717-746
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• 2014

21세기 지식 기반 사회에 적합한 인재는 자기주도적으로 지적 가치를 창출할 수 있는 자율적이고 창의적인 사고력을 갖춘 사람으로, 수학교육 현장에서는 학생들의 창의사고력이 강조되고 있다. 이러한 창의사고력은 자신의 사고과정을 모니터하고 조절 통제하는 메타인지능력과 밀접한 관련이 있다. 이에 본고에서는 메타인지와 관련된 여러 연구결과들의 통합을 통해 '메타인지능력과 수학적 사고력과의 상관관계, 메타인지 전략을 활용한 교수 학습 방법 및 그 효과, 메타인지 능력 향상을 통한 수학적 사고력 신장 방안'을 고찰하고자 하였다.