• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.644-651
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• 2001

The purpose of this study is to develop the improvement method of MOV(Motor Operated Valve) operability without major modification or change of MOV which needs a great expense and manpower. We studied valve stem lubrication, stem packing thrust and actuator control switch which could give an major effect to MOV operability, and found the some consequences. First, the stem/stem-nut friction coefficient and stem factor is significantly effected by stem lubrication state. Second, the measured packing thrust value is appeared higer than the design value for tested valves and the preparation of optimal value selection criteria is needed. Finally, optimization of MOV control switch is another major factor for MOV operability and structual integrity.

• 한국동물생명공학회지
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• 제36권4호
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• pp.175-182
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• 2021

Pluripotent stem cells could self-renew and differentiate into various cells. In particular, porcine pluripotent stem cells are useful for preclinical therapy, transgenic animals, and agricultural usage. These stem cells have naïve and primed pluripotent states. Naïve pluripotent stem cells represented by mouse embryonic stem cells form chimeras after blastocyst injection. Primed pluripotent stem cells represented by mouse epiblast stem cells and human embryonic stem cells. They could not produce chimeras after blastocyst injection. Populations of embryonic stem cells are not homogenous; therefore, reporter systems are used to clarify the status of stem cells and to isolate the cells. For this reason, studies of the OCT4 reporter system have been conducted for decades. This review will discuss the naïve and primed pluripotent states and recent progress in the development of porcine OCT4 reporter systems.

• 한국CDE학회논문집
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• 제5권2호
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• pp.122-126
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• 2000

A major mechanical problem with total hip replacement is the loosening of the femoral component. The loss of proximal support, with firm fixation distally, has been thought to be a major caused of fatigue failure of femoral stems. While many causes have been proposed, the most frequently suggested cause of the calcar resorption is the disuse atrophy of the cortex of the calcar due to the stress shielding of the proximal bone by the metal femoral stem. In this research, the new-designed stem(modified collar stem) was considered which made a hole inside stem and had a 3 mm thickness. Using the 3-dimensional finite element methods, the common collar stem and the modified colla stem was modeled and analysed. Also, the two models was compared. The results showed that the modified collar stem decreased the stress-shielding and it made a effective load transfer at the entire femoral region.

• 한국식생활문화학회지
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• 제16권3호
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• pp.235-242
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• 2001

Chemical properties of the different parts of watercress(Oenanthe javanica D.C.) grown and harvested from the culture fields under different cultivating methods were studied. In proximate analyses of watercress in parts, moisture contained more in stem than in root or in leaf, but crude protein and crude lipid contents were lower in stem than in root or in leaf. Crude ash in root contained up to about double amount in leaf or stem. Major mineral elements detected in watercress were Fe, Mg, Ca, and K, and their contents in root was higher than those in stem or leaf. Especially, Fe in root was significantly higher than that in stem or in leaf. Total free sugar composed mainly with fructose and glucose, was the highest in watercress from Hwasoon and followed the watercress from Jeonju and Donggok in order. Free sugar content was highest in leaf and the lowest in root. Major water-soluble vitamins were vitamin C, thiamin and biotin and the content of vitamin C was higher than others. These vitamins contained more in leaf than in stem or root. Niacin contained 6.09 mg/100 g in leaf of watercress from Hwasoon, which was much higher than others, but it was not detected in stem of watercress from Jeonju. Organic acids detected were oxalic acid, citric acid and malic acid and other 12 organic acids were not detected. In fatty acid composition, there were significant differences among watercresses from different parts and different culture fields. Linoleic acid, linolenic acid and palmitic acid were major fatty acids contained in watercress and it took about 80% of the total content. Amino acid content in leaf was higher than that in root and in stem. Glutamic acid and proline were major amino acids in stem of watercress from Jeonju and in stem of watercresses from Hwasoon and Donggok, respectively. In leaves of all three watercresses glutamic acid content was the highest.

• International Journal of Oral Biology
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• 제33권3호
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• pp.91-95
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• 2008

Embryonic stem cells have a pluripotency and a potential to differentiate to all type of cells. In our previous study, we have shown that embryonic stem cells (ESCs) lines can be generated from murine parthenogenetic embryos. This parthenogenetic ESCs line can be a useful stem cell source for tissue repair and regeneration. The defect in full-term development of parthenogenetic ESCs line enables researchers to avoid the ethical concerns related with ESCs research. In this study, we presented the results demonstrating that parthenogenetic ESCs can be induced into osteogenic cells by supplementing culture media with ascorbic acid and $\beta$-glycerophosphate. These cells showed morphologies of osteogenic cells and it was proven by Von Kossa staining and Alizarin Red staining. Expression of marker genes for osteogenic cells (osteopontin, osteonectin, alkaline phosphatase, osteocalcin, bone-sialoprotein, collagen type1, and Cbfa1) also confirmed osteogenic potential of these cells. These results demonstrate that osteogenic cells can be generated from parthenogenetic ESCs in vitro.

• 한국식품영양과학회지
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• 제19권2호
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• pp.133-142
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• 1990

This study was attempted to compare the nutritive value of leaf with stem of the water cress Oenanthe stolonifera DC. in order to improve the eating habits and as a part of studying on the effective curing nutrients for the damaged liver. The contents of moisture crude proteinon the effective curing nutrients for the damaged liver. The contents of moisture crude protein crude fat and crude ash were 90.40% 2.85%, 0.42% and 0.74% in leaf while the contents of moisture crude protein crude fat and crude ash were 95.15% 0.77% 0.09%, and 0.64% of moisture crude protein crude fat and crude ash were 95.15% 0.77% 0.09% and 0.64% in stem respectively. The quantitative fractionation of proteini of both leaf and stem ranked albumin the highest content followed globulin prolamin and glutelin in order. It has been sh-own by SDS-polyacrylamide gel electrophoresis that water extractable protein of leaf 11 bands but those of stem were not detected. The scope of molecular weight for the main protein of water extractable protein of leaf was between 34.700 and 45,000. The amounts of extractive-nitrogen from leaf and stem of the water cress were 241.02mg% and 271.67mg% respec-tively. The amounts of free amino acid-nitrogen from the leaf and stem were 89.02mg% and 32.02mg% respectively. In free amino acid-nitrogen from the leaf and stem were 89.02mg% and 32.02mg% respectively. In free amino acid composition of both leaf and stem the major components were aspartic acid and glutamic acid. In total amino acid composition of water cress leaf aspartic and glutamic acid were the major components. Whereas alanine and thr-eonine were the major components in stem The assessment of water cress leaf and stem with chemical score. EAAl Rl showed that the values of stem were lower tendancy than those of leaf. Limiting amino acid of leaf was tryptophan while that of stem was lysine.

• 한국식품과학회지
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• 제29권5호
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• pp.847-853
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• 1997

손바닥 선인장(Opuntia ficus-indica var. saboten)의 성분특성을 조사하여 식품으로의 이용 가능성을 검토하고자 하였다. 선인장과 알로에의 주성분은 가용성 무질소물이었다. 총무기질 함량은 선인장 줄기, 열매와 씨가 각각 9400.8, 6151.2와 1096.8 mg%이며, 주요 무기질은 Ca, P, Mg이었다. 주요 유리 아미노산은 선인장 열매인 경우 tyrosine, proline과 arginine이, 줄기는 glycine과 arginine이 씨의 경우 glutamic acid이었다. 총 아미노산중 주요 아미노산은 열매의 경우는 glutamic acid가, 줄기는 glycine과 arginine이었으며, 씨는 glutmic acid와 arginine이었다. 비타민 C는 열매와 줄기가 각각 163.8과 71.2 mg% 존재하나 씨에는 존재하지 않았으며, 비타민 A는 모든시료에서 검출되지 않았다. 총 폴리페놀 화합물과 플라보노이드 함량은 추출방법에 따라 다르며, 총 폴리페놀 화합물의 경우 선인장 열매가 줄기와 씨보다 함량이 높았으며, 총 플라보노이드 함량은 줄기와 열매에서 비슷하였다.

• 한국동물생명공학회지
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• 제34권3호
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• pp.139-147
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• 2019

Stem cells are progenitor cells that are capable of self-renewal and differentiation into various cells. Especially, pluripotent stem cells (PSCs) have in vivo and in vitro differentiation capacity into three germ layers and can proliferate infinitely. The differentiation ability of PSCs can be applied for regenerative medicine and tissue engineering. In domestic animals, their PSCs have a potential for preclinical therapy as well as the production of transgenic animals and agricultural usage such as cultured meat. Among several domestic animals, a pig is considered as an ideal model for biomedical and agricultural purposes mentioned above. In this reason, studies for pig PSCs including embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs) have been conducted for decades. Therefore, this review will discuss the history of PSCs derived from various origins and recent progress in pig PSC research field.

• 한국식품저장유통학회지
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• 제13권5호
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• pp.661-667
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• 2006

머위의 생리활성 기능과 이용 가능성에 관한 연구의 일환으로 머위의 잎과 줄기의 일반성분 및 영양성분을 조사하였다. 일반성분은 건물(dry basis)을 기준으로 머위 줄기는 잎보다 수분, 조지방, 조회분 및 탄수화물 함량은 높았으나, 조단백질 함량은 낮았다. 머위 잎은 D-fructose와 D-glucose의 2종의 유리당과 maltose와 lactose의 2종의 이당류가 검출되었고,줄기에서는 D-fructose와 D-glucose의 2종의 유리당과 lactose의 1종의 이당류가 검출되었다. 아미노산은 잎에서는 aspartic acid, glutamic acid, arginine, phenylalanine, leucine 순으로 검출되었으며, 줄기에서는 glutamic acid, aspartic acid, glycine, leucine 순이었다. 머위잎에는 불포화지방산인 linolenic acid를 가장 많이 함유되었고 그 다음으로 linoleic acid, palmitic acid, $\gamma$-linolenic acid순으로 검출되었다. 반면에 줄기에서는 5종의 불포화지방산이 검출되었으며 linoleic acid가 가장 많이 함유되었다. 유기산은 잎에서는 oxalic acid, succinic acid, citric acid 순으로 3종이 검출되었고, 줄기에서는 oxalic acid, malic acid, citric acid순으로 검출되었다. 머위 잎과 줄기에서 비타민 A, C와 E 3종이 검출되었다. 무기질은 머위 잎과 줄기에서 8종의 무기성분이 검출되었는데, 이 중 K이 가장 많이 함유되었다. 머위의 잎과 줄기의 일반성분 및 영양성분은 함량에서의 차이가 있을 뿐 성분은 매우 유사한 경향이었다. 이상의 결과 머위는 체내 신지대사와 생리활성을 증진시킬 수 있는 유리당, 필수아미노산 및 필수지방산을 비롯한 항산화 비타민과 무기질을 다량 함유하고 있어 머위의 식품으로서의 이용화 가치가 한 층 더 높아질 것으로 기대되어진다.

• 한국작물학회지
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• 제33권1호
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• pp.81-86
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• 1988

왕골 육종을 위한 형질상호간의 유전관계를 조기에 추정하고 효율적인 선발을 위한 기초자료를 얻고자 국내수집종 64품종을 공시하여 유전력, 표현형상관, 유전상관, 환경상관을 조사한 결과를 요약하면 다음과 같다. 1. 7개 형질에 대한 유전력 중 대부분의 형질에서는 높았으나 건피수량에서 만은 다소 낮게 평가되었다. 2. 형질상호간의 상관관계는 경장은 건수중과 건피수량에서, 경의 직경 역시 건수중과 건피수량에서 가장 높은 유의차로 정의 상관을 보였다. 3. 수량과 타형질과의 상관이 가장 높았든 형질은 경장, 경의 직경, 건수중이었으며 경로계수의 분석결과도 이들 형질의 직접효과가 가장 높았다.