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Bulblet Differentiation through the Formation of Friable Embryogenic Callus from Bulb Scales of Lilium longiflorum 'Nellie White' (Lilium longiflorum 'Nellie White'의 인편으로부터 Friable 배발생 캘러스를 통한 소자구 분화)

  • Han Bong-Hee;Lee Soo-Young;Shu Eun-Jung;Woo Jong-Gyu
    • Journal of Plant Biotechnology
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    • v.32 no.2
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    • pp.123-128
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    • 2005
  • A series of experiments were performed to establish regeneration system through friable embryogenic callus (FFC) of Lilium longiflorum 'Nellie White'. Only hard and regular callus was induced from bulb scales on medium containing 2.0 mg/L dicamba and $30{\sim}90$ g/L sucrose. The induced hard callus was subcultured on medium with 2.0 mg/L dicamba and 30 g/L sucrose, and used as a material for induction of FEC. In order to induce FEC, induced hard and regular callus was chopped into $1{\sim}2\;mm$ segments, and re-cultured on medium with 2.0 mg/L dicamba and 90 g/L sucrose. FEC was induced from chopped hard calli by the subcultures of two months interval. The induction rate of FEC was enhanced when hard callus was subcultured on same medium. FEC was proliferated more than 5 times on medium with $1.0{\sim}2.0\;mg/L$ dicamba and 90 g/L sucrose. Bulblet differentiation from FEC was very favorable on MS medium supplemented with 0.1 mg/L BA, 1.0 mg/L NAA and 30 g/L maltose, but many differentiated bulblets were changed to vitrificated ones. The differentiation of normal bulblets was most effective on medium containing $0.5{\sim}1.0\%$ activated charcoal and 30 g/L sucrose.

A SCANNING ELECTRON MICROSCOPIC STUDY OF END-IN-END AND END-TO-END MICROVASCULAR ANASTOMOSIS IN THE RAT FEMORAL ARTERY (백서 대퇴동맥에서의 혈관함입문합술과 혈관단단문합술의 주사전자현미경적 비교연구)

  • kim, Uk-Kyu;Chung, In-Kyo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.13 no.1
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    • pp.16-29
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    • 1991
  • The occurrence of thrombotic occlusion & endothelial injuries at the site of anastomosis have been considered as major problems in microvascular surgery. The purpose of this study was to ascertain whether a end-in-end(sleeve, telescope) anastomosis compared favorably with end-to-end anastomosis in healing procedures on the endothelium and to study the possibility of clinical application in end-in-end method. The microvascular anastomoses have been performed with end-in-end method in the femoral arteries of 20 rats group, also with end-to-end method on the same arteries of another 20 rats group, and then the four anastomosed vessels in subdivided groups on each group were taken after period of 1, 3, 7, 14, 21 days following by anastomoses for scanning electron microscope observation. The results were as following: 1. The patency rate was 90% in the end-in-end group and 85%in the end-to-end group and late thrombus occurred at 7, 14 days on both groups, which suggested -consistent monitoring of patency was required for two weeks at least. 2. Platelet aggregates at the site of anastomosis began to organize on post-operation 3 days and in the end-in-end group, the initially decreased lumen of inserted vessel was gradually increasing on 7 days due to atrophy of the medial layers. 3. Re-endothelialization was completed between 7 and 14 days in end-in-end group, whereas between 14 and 21 days in end-to-end group.

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Single-Stage AC/DC Converter with Low Conduction Loss and Power Factor Correction (저 도전 손실형 단단 역률보상 교류/직류 변환기)

  • 류명효;정종진;김흥근
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.1
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    • pp.79-87
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    • 2000
  • 본 논문은 저 도전 손실을 갖는 새로운 단단, 단일 스위치 역률보상 부스트형 교류/직류 변환기를 소개한다. 제안한 변환기는 약간의 구조적 차이점을 제외하고 기존의 변환기와 동일하게 해석될 수 있다. 먼저, 제안한 변환기와 기존의 변환기의 동작원리를 파악하여 두 변환기의 차이점을 이해하고 1단 역률 보상 교류/직류 변환기의 구조적 문제점인 에너지 저장 커패시터에서의 직류 전압 상승을 방지하기 위한 직류 부스 전압 궤환 방식을 도입하여 제안한 변환기에 적용하였다. 100W급 변환기를 제작/실험하여 본 변환기의 타당성을 검증하였다.

근섬유형태가 축육수리미의 젤 특성에 미치는 영향

  • Gang, Geun-Ho;Jeong, Jin-Yeon;Cheon, Se-Min;Ju, Seon-Tae;Park, Gu-Bu
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2005.05a
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    • pp.187-190
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    • 2005
  • 우육으로부터 제조된 수리미유사물의 낮은 pH는 가열된 수리미유사물의 젤 강도를 강하고 단단하게 하는 것과 관련이 있는 것으로 나타났다. 계육과 돈육은 근섬유가 더 굵고 직경이 큰 것으로 나타났고, 가열된 수리미유사물내 무정형 단백질의 부분적인 입자가 더 크게 형성하고 있는 것으로 나타났다. 가열된 수리미유사물의 젤 형성력과 조직감은 근원섬유단백질내 마이오신의 비율에 영향을 받는 것으로 나타났다. 마이오신의 비율은 우육으로부터 제조된 수리미유사물에서 가장 낮게 나타났고, 그 결과 수리미의 단단한 조직감과 젤 내 작은 덩어리가 많은 것으로 나타났다.

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Primary Neurofibroma of Trachea -A case Report- (기관에 발생한 원발성 신경섬유종)

  • 김준현;송태승;김동관;박승일;손광현
    • Journal of Chest Surgery
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    • v.31 no.1
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    • pp.82-85
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    • 1998
  • Benign tumors of the trachea are rare and are usually misdiagnosed as bronchial asthma because of the similarity of the symptoms and signs. Although the prognosis of neurofibroma which originats from Schwann cells is good, it may recur or undergo malignant change, so segmental resection of the trachea is recommended. Recently, we experienced a case of primary neurofibroma of the trachea treated successfully by segmental resection of the trachea and end-to-end anastomosis. We report it with a brief review of literatures.

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A Study on the Stiffness Estimation in Soft Tissue Using Speckle Brightness Variance Tracking (초음파 의료영상에서 스페클의 시간적 밝기 변화를 이용한 연조직의 stiffness를 추정하는 방법에 대한 연구)

  • 안동기;박정만;권성재;정목근
    • Journal of Biomedical Engineering Research
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    • v.24 no.3
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    • pp.141-149
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    • 2003
  • This paper proposes a method of measuring and imaging the stiffness of human soft tissue to diagnose cancers or tumors which have been difficult to detect in ultrasound B-mode imaging systems. To measure the soft tissue stiffness, sinusoidal vibrations are applied to it, and the magnitude of its mechanical vibration is determined by estimating the temporal variation of speckle pattern brightness in ultrasound B-mode images. It is verified by simulation and experiment that the proposed method can estimate the relative tissue stiffness from B-mode images with a relatively small amount of computation.