• 제목/요약/키워드: vascular system

검색결과 624건 처리시간 0.042초

산복사나무(Prunus davidiana FR.)의 성숙배와 유식물에 있어서 유관속계의 분화 (Differentiation of the Vascular System in Mature Embryo and Seedling of Prunus davidiana FR.)

  • 홍성식
    • Journal of Plant Biology
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    • 제28권4호
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    • pp.285-296
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    • 1985
  • To examine the differentiation and transition of vascular system in Prunus davidiana FR., the mature embyro and developing seedlings were embedded in paraplast and treated by clearing method. In mature embryo, the procambium was connected with the epicotyl-hypocotyl-radicle axis and cotyledons, whereas protophloem and protoxylem were restricted primarily to the mid-vein and two lateral veins of the cotyledonary base. With the onset of germination, protophloem and protoxylem were differentiated both acropetally and basipetally from the cotyledonary base. The first and second leaf traces appeared in the cotyledonary node, and then differentiated bidirectionally toward the epicotyl and the root tip. The 3rd to 6th leaf traces were connected with the cotyledonary traces in hypocotyl. At the part of the root tip, the xylem was a diarch. As the first and second leaf traces were superimposed at the middle part of the root, the diarch xylem was changed to a tetrarch. As the cotyledonary traces were diverged below the root base, the tetrarch xylem was changed to an octarch. It was suggested that the vascular system of the epicotyl might be superimposed on that of the cotyledon-hypocotyl-root during the formation of the primary vascular system of Prunus davidiana.

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Antihistamine Effects of Triprolidine from the Transdermal Administration of the TPX Matrix in Rats

  • Shin Sang-Chul;Choi Jun-Shik
    • Archives of Pharmacal Research
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    • 제28권1호
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    • pp.111-114
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    • 2005
  • The antihistamine effects of the triprolidine were studied in rats to determine the feasibility of their enhanced transdermal delivery from the poly (4-methyl-1-pentene) (TPX) matrix system containing penetration enhancer and plasticizer. The antihistamine effects were determined by the Evans blue dye procedure by comparing the changes in vascular permeability increase following the transdermal administration. The vascular permeability increase was significantly reduced by transdermal administration of the triprolidine-TPX system containing triethyl citrate (TEC) and polyoxyethylene-2-oleyl ether (POE). Both the plasticizer and penetration enhancer played an important role in the skin permeation of triprolidine and increased the antihistamine effects. These results showed that the triprolidine-TPX matrix system containing plasticizer and penetration enhancer could be a transdermal delivery system providing the increased antihistamine effects.

A Prediction Model of Blood Pressure Using Endocrine System and Autonomic Nervous System

  • Nishimura, Toshi Hiro;Saito, Masao
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 추계학술대회
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    • pp.113-118
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    • 1991
  • Hypertension is a medical problem with no permanent cure. Extended hypertension can cause various cardio vascular diseases, cerebral vascular diseases, and circulatory system trouble. Medical treatment at present does not consider circadian variation of blood pressure in patients ; therefore, the problem of over-reduction of blood pressure through drugs sometimes occurs. This paper presents a prediction model of circadian variation or moon blood pressure employing the endocrine grand and the autonomic nervous system.

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Vascular Endothelial Cadherin-mediated Cell-cell Adhesion Regulated by a Small GTPase, Rap1

  • Fukuhra, Shigetomo;Sakurai, Atsuko;Yamagishi, Akiko;Sako, Keisuke;Mochizuki, Naoki
    • BMB Reports
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    • 제39권2호
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    • pp.132-139
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    • 2006
  • Vascular endothelial cadherin (VE-cadherin), which belongs to the classical cadherin family, is localized at adherens junctions exclusively in vascular endothelial cells. Biochemical and biomechanical cues regulate the VE-cadherin adhesive potential by triggering the intracellular signals. VE-cadherin-mediated cell adhesion is required for cell survival and endothelial cell deadhesion is required for vascular development. It is therefore crucial to understand how VE-cadherin-based cell adhesion is controlled. This review summarizes the inter-endothelial cell adhesions and introduces our recent advance in Rap1-regulated VE-cadherin adhesion. A further analysis of the VE-cadherin recycling system will aid the understanding of cell adhesion/deadhesion mechanisms mediated by VE-cadherin in response to extracellular stimuli during development and angiogenesis.

정맥패턴인식을 위한 고속 원형정합 (Fast Template Matching for the Recognition of Hand Vascular Pattern)

  • 최광욱;최환수;표광수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.532-535
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    • 2003
  • In this paper, we propose a new algorithm that can enhance the speed of template matching of hand vascular pattern person verification or recognition system. Various template matching algorithms have advantages in the matching accuracy, but most of the algorithms suffer from computational burden. To reduce the computational amount, with accuracy maintained, we propose following template matching scenario as follows. firstly, original hand vascular image is re-sampled in order to reduce spatial resolution. Secondly, reconstructed image is projected to vertical and horizontal direction, being converted to two one dimensional (1D) data. Thirdly, converted data is used to estimate spatial discrepancy between stored template image and target image. Finally, matching begins from where the estimated order is highest, and finishes when matching decision function is computed to be over certain threshold. We've applied the proposed algorithm to hand vascular pattern identification application for biometrics, and observed dramatic matching speed enhancement. This paper presents detailed explanation of the proposed algorithm and evaluation results.

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Angiographic PIV 기법을 이용한 혈액유동의 in-vitro 연구 (In vitro application of Angiographic PIV technique to blood flows)

  • 김국배;임남윤;정성용;이상준
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2007년도 추계학술대회
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    • pp.105-108
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    • 2007
  • To diagnose the vascular diseases from the viewpoint of hemodynamics, we need detailed quantitative hemodynamic information of related blood flows with a high spatial resolution of tens micrometer and a high temporal resolution in the order of millisecond. For investigating in-vivo hemodynamic phenomena of vascular circulatory diseases, a new diagnosing technique combining a medical radiography and PIV method was newly developed. This technique called 'Angiographic PIV system' consists of a medical X-ray tube, an X-ray CCD camera, a shutter module for generating double pulse-type X-ray, and a synchronizer. Through several preliminary tests, the feasibility of the Angiographic PIV technique was verified. For in-vivo applications to real blood flows, we developed tracer microcapsules, which were optimized to this system, made of a contrast material of iodine and a matrix material of PVA (polyvinylpyrrolidone). In near future, the Angiographic PIV technique will be used for understanding hemodynamic phenomena of vascular diseases and for their early detection.

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쥐 뇌의 고해상도 이미지에서 임계화 기법을 활용한 뇌혈관 네트워크 분석 및 3D 재현 (Analysis and 3D Reconstruction of a Cerebral Vascular Network Using Image Threshold Techniques in High-resolution Images of the Mouse Brain)

  • 이준석
    • 한국멀티미디어학회논문지
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    • 제22권9호
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    • pp.992-999
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    • 2019
  • In this paper, I lay the foundation for creating a multiscale atlas that characterizes cerebrovasculature structural changes across the entire brain of a mouse in the Knife-Edge Scanning Microscopy dataset. The geometric reconstruction of the vascular filaments embedded in the volume imaging dataset provides the ability to distinguish cerebral vessels by diameter and other morphological properties across the whole mouse brain. This paper presents a means for studying local variations in the small vascular morphology that have a significant impact on the peripheral nervous system in other cerebral areas, as well as the robust and vulnerable side of the cerebrovasculature system across the large blood vessels. I expect that this foundation will prove invaluable towards data-driven, quantitative investigations into the system-level architectural layout of the cerebrovasculature and surrounding cerebral microstructures.

Development of Construction Site Access Management Automation System based on Hand Vascular Pattern

  • Gu Taek Kim;Ji Woong Yeom;Kyong Hoon Kim;Choong Hee Han;Jae Jun Kim
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.499-505
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    • 2009
  • Along with the changing pattern that the construction project is getting complicated, large-scaled and up-to-dated, necessity of efficient management of manpower and resources of the construction site is being increased. In particular, considering that the construction site requires a lot of labor force and in terms of the construction cost, labor cost shares 30-40%, labor management has become a very important factor. In this study, in order to support a stable and successful construction project implementation and supplement the existing system being utilized at the current site, construction site access management automation system based on hand vascular pattern, a biometrics system, is intended to be developed. Relevant theory for the system development and the problem of existing RFID system were evaluated and based on this findings, a system design and DB composition chart were envisaged. In addition, by applying this developed system to a number of sites, its result was analyzed

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손혈관 인식 시스템의 경쟁기술현황과 전망 (Forecast and Present Technology of Hand Vascular Pattern Recognition System)

  • 김재우;여운동;배상진;성경모
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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    • pp.114-116
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    • 2004
  • Biometrics consist of technologies that support automatic identification or verification of identity based on behavioral or physical traits. Biometrics can authenticate identities since they measure unique individual characteristics including fingerprints, hand geometry, iris, hand vascular patterns and facial characteristics. we review the state of the hand vascular patterns identification technology and compare other competitive authentication technologies such as cryptography, electronic signature and PKI.

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