• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.61-66
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• 2008

More than 70% of Korea consists of mountainous area and during the construction of roads and railroads many cut-slopes are inevitably formed. A number of environmental factors, such as the rainy season and frost heave during winter/thaw during spring, can result in rock falls and landslides. The failure of slopes is increasing every year and can cause damage to vehicles, personal injury and even fatality. In order to help protect people and property, there is a need for real-time monitoring systems to detect the early stages of slope failures. In this respect, the GMG has been using Translation Rotation Settlement (TRS) sensor units installed on slopes to monitor movement in real-time. However, the data lines of this system are vulnerable and the whole system can be damaged by a single lightning strike. In order to overcome this, GMG have proposed the use of Ubiquitous Sensor Networks (USN). The adoption of a USN system in lieu of data cables can help to minimize the risk of lightning damage and improve the reliability of slope monitoring systems.

• Journal of fish pathology
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• v.24 no.3
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• pp.205-211
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• 2011

All of the crucian carp, Carassius auratus and 50% of common carp. Cyprinus carpio examined in this study were infected with the leeches, Limnotrachelobdella sinensis. Especially, the infection of C. carpio with L. sinensis was the first report in Korea. The gill of C. auratus showed increased hydrophic degeneration of epithelial cell in the filament, blood congestion, hyperplasia of epithelial cell in the filament and lamellae. In the SEM observation, gill filament was transformed to the cylinder form by the lamellae fusion. The lamellae surface showed degeneration, fragmentation of microridges. The extracellular cartilaginous matrix of the filaments was exposed by the collapse of epidermal layer. In the 18S rRNA analysis of L. sinensis, the relationships among these groups are not clear and not concord with their morphological classification.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.384-387
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• 2009

Radial artery aneurysm is an extremely rare disease and this is usually caused by iatrogenic trauma such as arterial cannulation. Most traumatic aneurysms in the extremities are false aneurysms and most cases have occurred at the level of the wrist. Very few true aneurysms of the radial artery have been reported, with most of them being iatrogenic. A right handed 38-year-old female had a true aneurysm of the distal radial artery in the thenar groove of the palm. The patient had a history of excessive handclapping and the injury was suggestive of repetitive occupational injury due to scissoring. She underwent surgical treatment for the aneurysm of the radial artery in the thenar groove of the palm of her hand.

• Journal of Embryo Transfer
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• v.9 no.3
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• pp.255-260
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• 1994

원시생식세포(primordial germ cell; PGC)는 성성숙 이후에 기능을 갖는 생식세포의 근원이 되는 세포로서, 다능성을 갖고 있는 것으로 알려져 있다. 그러므로 chimera 및 유전자 변환동물 생산을 위해 널리 사용되어 온 배아주(embrynic stem; ES)세포를 대신할 다른 세포계라고 생각되어져 많은 연구가 진행되고 있다. 본 실험은 체외배양을 통하여 원시생식세포의 증식과 확립을 위해 배양조건을 구명하고, 또한 성장인자의 효과를 검증하기 위하여 실시되었다. 원시생식세포는 12.5일째의 ICR 생쥐태아의 원시생식선 융기조직으로부터 추출하였으며, DMEM + 20% FCS + nucleosides + antibiotics로 조성된 sDMEM 배양액을 사용하여 mitomycin C로 전처리한 되먹임세포단층(feeder layer)위에서 체외배양하였다. bFGF 및 LIF를 20, 40ng/ml농도로 각각 또는 함께 첨가하여 성장인자의 효과를 검토하였다. 원시생식세포는 성에 따라 유의적인 colony 형성율을 보였고(♂:1.9 colonies / genital ridge, ♀:1.3 colonies / genital ridge), bFGF 및 LIF의 첨가 및 첨가농도에 따라서도 유의성 있는 결과를 보였다(0.3~1.9 colonies / genital riege). 그러나 3회 이상 계대배양을 할 경우, 원시생식세포의 colony를 4% prarformaldehyde로 20분간 고정한 후, tris-maleate buffer(pH 9.0)로 10분간 3회 세정하였다. Fast Red로 염색을 실시한 결과, 대부분의 colony가 염색반응을 보여 다능성을 갖는 원시생식세포의 colony임이 입증되었다. 그러나 대부분의 colony가 3회 이상의 계대배양시 생종율이 급격히 떨어지는 것을 감안하면, 또 다른 미지의 성장인자나 보다 적절한 배양조건이 요구된다고 생각된다.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.638-645
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• 2010

This study introduces a reinforcement work case using Twin-Jet Method. The area is located behind the abutment of the bridges built on soft clay along the $\bigcirc\bigcirc$ Express Highway. Its foundation was constructed by installing EPS blocks on the original ground to reduce the embankment load under the highway. However, the ground deformation has continuously occurred due to the settlement of the foundation soft cohesive soils. The amounts of subsidences at the surface turned out to be 20~30.0mm, After the pavement patch work on April 23, 2009, a drastic subsidence occurred together with 10mm swell, For this reason, Twin-Jet grout column construction was applied by passing through the EPS banking blocks without closing traffic flows on the express highway. The outcomes of core sample tests after reinforcing the ground turned out to be TCR 92.5%, RQD 64.6% and unconfined compressive strength 2.3~8.6Mpa. The test results showed that the condition of the ground foundation had improved using Twin-Jet grouting in most layers of ground including the cobble and gravel layer.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.145-151
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• 2000

The mouthparts of the Apionidae are almost of the same structures as in the Curculionidae feeding soft plant tissues, and two subfamilies in the current system are well supported by their structures. The subfamilies Apioninae and Nanophyinae are clearly characterized as follows. In Apioninae, clypeal margin sinuate; mandibles meet anteropo-steriorly when retracted and more or less curved internally; maxillary palpi two-segmented, with large palpiger; labial palpi one-segmented; prementum parallel-sided, longer than wide. In Nanophyinae, clypeal margin with two to three notches in the middle; mandibles meet anteroposteriorly when retracted and more or less curved internally; maxillary palpi three-segmented, palpiger about as great as stipes; labial palpi two-segmented, separated to each other by the apical protrusion of prementum; prementum about as long as wide. [Insecta, Coleoptera, Comparative morphology, Mouthparts, Apionidae].

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.34-45
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• 1999

Mafic granulite xenoliths are found in precambrian porphyroblastic gneiss of the Mt. Jiri area, SW Sobaegsan massif, Korea. The xenoliths are rounded to ellipsoidal in shape, 50-100 cm in length and coarse-grained with granoblastic and foliated texture. The xenoliths consist of orthopyroxene, garnet, biotite, plagioclase, quartz, ilmenite and secondary orthoamphibole. Orthopyroxene is mostly resorbed and rimmed by coronitic orthoamphiboles. Garnets occur as porphyblasts and are zoned with higher pyrope content in cores than in rims. Geothermo-barometry results yield conditions of about $800-850^{\circ}C$, 6 kb and $500^{\circ}C$, 4 kb for early and retrograde stages of equilibration, respectively. According to available geochronological data, it is suggested that the granulite facies metamorphism occurred prior to 2.1-1.9Ga and that the area was superimposed by the high-grade (over $600-700^{\circ}C$) metamorphism between 1.9-1.7Ga, followed by cooling during uplift.

• The Journal of the Petrological Society of Korea
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• v.13 no.3
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• pp.152-160
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• 2004

$^{40}Ar-^{39}39/Ar$ ages were determined from the biotites and plagioclases separated from the Precambrian gneisses of Gyeonggi Massif. Biotites yield $1,294{\pm}46,\;1,241{\pm}39\;and\;1,217{\pm}39Ma(2{\sigma}\;errors)$, and plagioclases yield $934{\pm}25,\;872{\pm}19,\;819{\pm}15(2{\sigma})Ma$. These ages are significantly different from the U-Pb zircon ages obtained from the identical samples ($1,613{\pm}51~2,168{\pm}24Ma(2{\sigma})$, Song et al., 2001). The ages of biotites and plagioclases can be interpreted to represent independent regional thermal events. The Mesoproterozoic ages recorded by the biotites can be interpreted as a consequence of regional metamorphism followed by differential uplift. We propose that plagioclases record Neoproterozoic ages which are related with igneous activities under the regional extensional regime, related with the breakup of the supercontinent Rodinia existed at that time.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.85-85
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• 1997

스트레스가 유발된 랫드의 대뇌에서 Vasopressin-catecholamine pathway의 활성도를 알아보기 위해 면역화학염색법으로 vasopressin 호르몬의 분비와 catecholamine의 생성변화를 tyrosine hydroxylase (TH) 효소의 발현변화로 규명하고, arginine vasopressin (AVP)과 V1 vasopressin receptor의 유전자 발현변화를 in situ hybridization 방법을 이용하여 살펴보았다. 수컷 SD rat를 7시간동안 stress cage에 넣어 16$\pm$1$^{\circ}C$의 물에 수침구속 스트레스를 준 후 대조군과 함께 관류고정하여 brain을 적출하였다. Brain의 hypothalamus 부위를 중심으로하여 동결절편하여 면역조직화학 염색과 in situ hybridization을 시행하였다. TH 면역조직화학 염색에서 대뇌의 줄무늬체 부위의 꼬리조가비핵에서와 시상하부 부위의 내측등쪽시상하부와 흑색질부위에서 스트레스군이 대조군에 비해 TH 면역염색성이 증가되어 관찰되었으나 시상하부 부위의 시삭위핵, 뇌실주위핵, 뇌실옆핵에서는 두 군간의 큰 면역염색성의 차이는 보이지 않았다. AVP 면역조직화학 염색에서는 시삭위핵에 많은 수의 AVP 양성 신경세포체들이 밀집되어 있으며 뇌실옆핵에서는 스트레스군에서 AVP 면역염색성이 약간 증가되어 관찰되었으나 신경섬유의 분포양상은 비슷하였다. 중간융기에서는 모두 강한 염색성의 신경섬유들이 관찰되어 두 군간에 큰 차이는 없었다. AVP 유전자에 대한 in situ hybridization 결과 시삭위핵의 신경세포에서 AVP mRNA 양성반응을 관찰할 수 있었으나 다른 시상하부핵에서는 관찰할 수 없었으며, V1 vasopressin receptor에 대한 in situ hybridization 결과는 두 군의 대뇌에서 모두 양성반응을 관찰할 수 없었으며 V1 vasopressin receptor 유전자의 조직별 발현정도와 스트레스에 의한 발현량 조절을 관찰할 필요가 있다고 사료된다.

• Elastomers and Composites
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• v.49 no.1
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• pp.73-81
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• 2014

Friction and wear behaviors of natural rubber(NR) compounds were investigated using a blade-type abrader. The effects of temperature, normal load, and rotation speed on wear rate were studied, and wear behaviors of deteriorated compounds were also evaluated. As the rotation speed of specimen and the normal load to specimen increased, the wear rate increased. However, as the experimental temperature increased, the frictional coefficient decreased and the wear rate decreased accordingly. It was found from the wear studies that a power-law relation works between the frictional work input and the wear rate. It was observed that the wear rate dramatically increased by the degradation of the rubber specimen. The wear pattern was developed and the bigger ridge space of the pattern was observed usually in the higher normal load applied. In determining the wear rate of rubber compound, the continuous measurements of wear distance using the blade-type abrader could be successfully used instead of intermittent measurements of wear-loss weight.