• 제목/요약/키워드: Human vessels

검색결과 325건 처리시간 0.027초

Automatic Segmentation of Retinal Blood Vessels Based on Improved Multiscale Line Detection

  • Hou, Yanli
    • Journal of Computing Science and Engineering
    • /
    • 제8권2호
    • /
    • pp.119-128
    • /
    • 2014
  • The appearance of retinal blood vessels is an important diagnostic indicator of serious disease, such as hypertension, diabetes, cardiovascular disease, and stroke. Automatic segmentation of the retinal vasculature is a primary step towards automatic assessment of the retinal blood vessel features. This paper presents an automated method for the enhancement and segmentation of blood vessels in fundus images. To decrease the influence of the optic disk, and emphasize the vessels for each retinal image, a multidirectional morphological top-hat transform with rotating structuring elements is first applied to the background homogenized retinal image. Then, an improved multiscale line detector is presented to produce a vessel response image, and yield the retinal blood vessel tree for each retinal image. Since different line detectors at varying scales have different line responses in the multiscale detector, the line detectors with longer length produce more vessel responses than the ones with shorter length; the improved multiscale detector combines all the responses at different scales by setting different weights for each scale. The methodology is evaluated on two publicly available databases, DRIVE and STARE. Experimental results demonstrate an excellent performance that approximates the average accuracy of a human observer. Moreover, the method is simple, fast, and robust to noise, so it is suitable for being integrated into a computer-assisted diagnostic system for ophthalmic disorders.

보튤리눔 톡신-A가 백서의 임의 피판 생존율에 미치는 영향 (The Effect of Botulinum Toxin-A on the Survival of Random-Pattern Cutaneous Flap in Rat)

  • 김영석;이재수;유원민;탁관철
    • Archives of Plastic Surgery
    • /
    • 제35권4호
    • /
    • pp.360-366
    • /
    • 2008
  • Purpose: Botulinum toxin type A(BoTA) can block the release of vasoconstriction cotransmitters as well as acetylcholine in nerve terminal. The authors observed that BoTA increases flap survival by preventing sympathetic collapse of peripheral vessels. Methods: 10 Sprague Dawley rats were divided into control(n=5), and BoTA group(n=5). $3{\times}10cm$ sized random pattern cutaneous flaps were elevated on the dorsal side in both groups. In BoTA group, BoTA was injected into the flap via intradermal to subdermal route, 7 days before the flap elevation. Flap survival rates (survival area/total area) were measured 7 days after the elevation. Cutaneous blood flow was measured in proximal, middle and distal compartments of the flap using laser Doppler flowmetry initially, preoperatively, at immediate postoperation, and 7 days after flap elevation, respectively. Histological examination was performed 7 days after the flap elevation. The number and shape of the vessels were evaluated under microscope. Results: Mean flap survival was $53.18{\pm}6.58%$ in control group and $93.79{\pm}6.06%$ in BoTA group, displaying statistically significant difference(p=0.0008, p<0.05). In the control group, blood flow to the middle and distal compartments of the flap decreased significantly immediately after flap elevation. In the BoTA group, blood flow to the middle compartment did not decrease(p=0.002) and slightly decreased in the distal compartment(p=0.001). Cutaneous blood flow was significantly higher in all compartments of the flap in BoTA group than in control group, 7 days after the flap elevation. In histopathologic examination, greater number of vessels were noted in the BoTA group than in the control group. Conclusion: Botulinum toxin A can increase the survival of the random pattern cutaneous flap in rats by preventing the sympathetic collapse of peripheral vessels.

함정용 Al 및 Zn 희생양극의 효율에 미치는 첨가원소 영향 (Effect of Additional Elements on Efficiency of Al and Zn Sacrificial Anode for Naval Vessels)

  • 최우석;박경철;김병호
    • 한국항해항만학회지
    • /
    • 제39권4호
    • /
    • pp.277-283
    • /
    • 2015
  • 함정에 사용되는 선체재료로는 연강, 고장력강, 고강도강, 알루미늄 합금 및 복합재료 등이 있다. 그 중 함정의 선체는 수밀과 강도의 유지 및 탑재장비의 지지 등 기본적인 기능을 위하여 철강 재료를 주로 사용하고 있다. 함정의 주 임무는 해양에서 작전을 수행하는 것이므로 해수에 의한 선체 부식이 필연적으로 발생하게 된다. 선체의 부식을 방지하기 위하여 도장 방법, 희생양극법 및 강제 전류 방식이 사용되고 있다. 특히 Al 및 Zn을 활용한 희생양극법의 경우 부식특성 개선을 위하여 인듐(In), 카드뮴(Cd) 및 납(Pb) 등의 중금속이 첨가되어 있다. 하지만 이러한 중금속은 인체 및 환경에 매우 유해하므로 전 세계적으로 사용이 점차 규제되고 있다. 이에 본 논문에서는 인체 및 환경에 무해한 미세원소(Ma, Ca, Ce 및 Sn)를 첨가하여 Al 및 Zn 합금을 제조하였다. 제조된 함정용 Al 및 Zn 희생양극의 효율 특성 측정을 위하여 SEM, XRD, 동전위 분극실험 및 전류효율 평가를 실시하였으며, 실험결과 Al-3Zn-0.6Sn 및 Zn-3Sn 합금의 양극 성능이 다른 합금 보다 효율성이 우수하였다.

Relaxin을 분비하는 아데노바이러스가 피판의 생존에 미치는 영향 (Effect of Relaxin Expressing Adenovirus for Rat Skin Flap Viability)

  • 윤인식;박용순;전영우;전여름;이원재;윤채옥;나동균
    • Archives of Plastic Surgery
    • /
    • 제37권5호
    • /
    • pp.519-525
    • /
    • 2010
  • Purpose: Of various effects of relaxin, we assumed that anti-fibrotic effects, neovascularization effects and vasodilatation effects of relaxin might enhance the survival rate of skin flap. In the current study, we used adenovirus expressing relaxin genes to examine whether these genes could enhance the survival rate of a skin flap. Methods: A total of 30 Sprangue-Dawley rats were divided into three groups: RLX group (10; relaxin virus injected group), CTR group (10; no gene coded virus injection group), and PBS group (10; PBS injected group). Each group was intradermally injected with the virus ($10^7$ PFU) and PBS 48 hours before and immediately before the flap elevation. A distally based flap $3{\times}9\;cm$ in size was elevated on the dorsal aspect of each rat. Following this, a flap was placed in the original location and then sutured using a #4-0 Nylon. A surviving area of the flap was measured and then compared on postoperative days 3, 7 and 10. Using a laser Doppler, the amount of blood flow was measured. On postoperative day 10, tissues were harvested for histologic examination and the number of blood vessels was counted. Results: There was a significant increase in the area of the flap survival in the RLX group on postoperative days 3 and 7. The Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of blood vessels was significantly greater in the RLX group in the tissue harvested on postoperative day 10. The VEGF concentration was significantly higher in the RLX group than others in the tissues harvested on postoperative day 10. Conclusion: Following an analysis of the effects of relaxin-secreting adenovirus on the survival of a flap, the surviving area of the flap and the blood flow also increased. A histopathology also showed an increase in the number of blood vessels and the concentration of VEGF.

해상에서의 선박 음주운항 단속 강화를 위한 법 제도 분석 (An Analysis of Legal System for Strengthening Actions against Operating Vessels Under the Influence of Alcohol at Sea)

  • 한재진;정봉훈;국승기;윤준호
    • 한국항해항만학회지
    • /
    • 제45권1호
    • /
    • pp.33-41
    • /
    • 2021
  • 최근 5년간 해상에서 음주운항으로 적발된 건수는 총 567건으로 대부분 어선에서 발생하고 있으며, 음주운항으로 인한 사고건수는 69건으로 5명이 사망하고, 1명이 실종되는 등 해상에서는 음주운항으로 인한 사고로 인적 물적 피해를 주고하고 있다. 그러나 음주운항으로 사회적 피해가 증가하고 있으나, 현행 법령상 처벌은 위반행위의 중대성에 비해 가볍게 처리되고 있는 실정이다. 이에 음주운항으로 인한 사고의 재발방지를 위해 우리나라의 음주운항 사례를 분석하고, 외국의 음주운항 단속 규정을 비교 검토하였다. 또한 선박 종사자를 대상으로 음주운항의 위험성을 계도 홍보하는 한편, 관련 법률 및 제도를 개선해야 한다. 그리고 해상에서 선박에 대한 해양경찰에서의 단속을 강화하여 음주운항 사고를 줄이기 위해 노력을 지속해야 하며, 향후 선박에서의 음주로 인한 안전사고가 사전에 예방될 것으로 기대된다.

무인화 선박에 대한 한국 선원들의 인식에 관한 연구 (A Study on Korean Seafarer's Perceptions Towards Unmanned Ships)

  • ;류동근;조소현
    • 한국항해항만학회지
    • /
    • 제41권6호
    • /
    • pp.381-388
    • /
    • 2017
  • 최근 무인화 선박과 관련하여 해양 산업 분야에서의 기술적인 응용에 대한 관심이 일어나고 있다. 특히 기술, 안전 및 보안 문제와 관련하여 무인 선박의 운영 가능성을 시험하고 개발하는 것을 목표로 하는 많은 연구에 대한 관심이 모아지고 있다. 이처럼 선박은 매우 빠르게 기술 개발이 이루어지고 있으며 결국에 선원이 승선하지 않아도 되는 무인화 및 지능형 선박의 개발까지 이어지게 되었다. 하지만 현재까지 선원들의 관점에서 선박의 기술적 변화와 앞으로 도입될 무인화 선박에 대한 그들의 인식에 관한 연구는 없었다. 4차 산업 혁신 중에 하나일 선박의 자율운항기술은 선원의 일자리, 선원의 노동과 윤리적 분야, 교육과 훈련 등 영향을 미칠 것이며 이는 선원의 선상 근무가 필요 없는 무인 선박의 개발에 앞서서 논의되어야 할 사항이다. 이러한 논의의 시작으로 본 연구는 무인화 선박에 대한 선원의 지식과 인식이 어떠한지 조사하고 분석하는 것을 목적으로 한다. 이를 위해 응답자를 대상으로 조사 설문지를 통해 데이터를 수집했으며 변수들 간의 상관 관계를 테스트하는 데 피어슨 상관 계수를 사용하였다.

합성수지주입법(合成樹脂注入法)에 의한 개내장(內臟)의 준조대해부학적(準粗大解剖學的) 연구(硏究) 제(第)1보(報) 폐(肺)의 기관분지(氣管分枝) 및 혈관분포(血管分布)에 관(關)하여 (Studies on the Subgross Anatomy of the Conine Viscera by the Vinylite-Corrosion Technique 1. The Distribution of Bronchial Branches and BloodVessels in the Lung)

  • 모기철
    • 대한수의학회지
    • /
    • 제6권1호
    • /
    • pp.57-75
    • /
    • 1966
  • This study was conducted to observe the condition of the ramifications of the bronchus and pulmonary blood vascular system by injecting the vinylite into the bronchial tree and pulmonary blood vessels in 100 normal adult dogs. The results obtained were summarized as follows: 1. Lungs of dog were composed of the same pulmonary territories as in lungs of human. 2. Cardiac lobe corresponding to R.medio-bassalis of human lungs was well developed and situated as a independent cardiac lobe, in ventral side of right lung. 3. Bronchial tree were in the patterns of axial divergency and blood vascular systems were (in general) branched along the bronchial tree, arteries lying near the bronchial tree but veins apart from it. 4. Among the branching patterns of bronchus pulmonary artery and pulmonary vein in each lobe, the type presented most frequently were noted, which were designated basic type by the author. 5. Pulmonary blood vessels were not always branched in accordance with bronchial tree, diverged inmore complex patterns, especially in venous vascular system. 6. Ramus anterior (lobe apicalis) was always observed in all casting specimen. 7. There was a case of peculiar variation patterns of the ramification in the bronchi directing into the left apical and cardiac lobe, arose respectivelly, at independent origin of bifurcation in the left bronchial stem, and a case of peculiar variation pattern of the artery entering left apical lobe and cardiac lobe, had a same origin of the bifurcation at rami pulmonary artery, and then divided respectivelly into the rami medi artery and rami left apical lobe artery. 8. In the classification based on the patterns of bronchial and blood vasculor divergencys, there were a lot of significant combination cases in their patterns.

  • PDF

국제사회의 대북제재와 남북수산협력 (International Sanction on North Korea and Inter-Korea Fisheries Cooperation)

  • 박준모
    • 수산경영론집
    • /
    • 제50권4호
    • /
    • pp.11-28
    • /
    • 2019
  • In this study, the Inter-Korea Fisheries Cooperation Project was divided into four categories: North Korea's Fisheries Infrastructure Development Project, Fisheries Cooperation Project, Human Exchange Project, and North Korea Fisheries Investment Project. First, North Korea's fisheries infrastructure development projects include North Korea's fisheries resource research project, it's fisheries resource development project, and joint enforcement on illegal operation of Chinese ships. Second, fisheries cooperation projects include the operation of the North-South common fish area in the West Sea, the fishing project in North Korea's East sea, and the import of North Korean seafood. Third, human exchange projects include training of aquaculture technicians in North Korea, technology transfer and training of fishing vessels, and boarding of North Korea's fisherman in Korean fishing vessels. Fourth, North Korea's fisheries investment projects include aquaculture facilities and aquaculture feed support, aquatic product processing facilities and technology transfer, and fishery equipment support. However, as international sanctions are maintained in the international community to North Korea, Inter-Korea Fisheries cooperation, however, should be promoted according to the level of easing of international sanctions as international sanctions are maintained in the international community to North Korea. First, North Korea's fisheries resource research project, North Korea's fisheries resource creation project, joint enforcement on illegal operation of Chinese ships, and operation of the common fish area in the West Sea can be promoted if international sanctions are maintained at present, promote North Korea's fisheries resource research project. Second, boarding of North Korean's fisherman in Korean fishing vessels, conducting the fishing project in North Korea's East sea, and importing North Korean seafood can be aided if commercial transactions are possible with North Korea. Third, South Korea will support aquaculture facilities and aquatic feed, fisheries processing facilities and technology transfer, fishery equipment support, training of fisheries and aquaculture technicians, fishery fishing technology transfer, and training of fisherman when a comprehensive economic cooperation project is possible with North Korea.

Perforating patterns of cutaneous perforator vessels in anterolateral thigh flaps for head and neck reconstruction and clinical outcomes

  • Lee, Sang Soo;Hong, Jong Won;Lee, Won Jae;Yun, In-Sik
    • 대한두개안면성형외과학회지
    • /
    • 제23권2호
    • /
    • pp.64-70
    • /
    • 2022
  • Background: Anterolateral thigh (ALT) flaps are versatile soft tissue flaps that have become the standard soft-tissue flaps used for head and neck reconstruction. They provide a long vascular pedicle, constant vessel diameter, abundant soft tissue coverage, and minimal donor site morbidity. The ALT flap was initially designed on the basis of a septocutaneous (SC) perforator. However, more recent research has shown that a substantial number of ALT flaps are now based on musculocutaneous (MC) perforators, and the ratio between MC and SC perforators varies among studies. In this study, we analyzed the perforating pattern of ALT flaps along with their clinical outcomes during head and neck reconstruction in the Korean population. Methods: From October 2016 to July 2020, 68 patients who had undergone an ALT flap procedure for head and neck reconstruction were enrolled retrospectively. The perforating pattern of the cutaneous perforator vessel (MC perforator/SC perforator/oblique branch), pedicle length, and flap size were analyzed intraoperatively. Patient demographics and flap necrosis rates were also calculated. Results: The highest number of cutaneous perforator vessels supplying the ALT flap were the MC perforators (87%). The proportion of MC perforators was significantly higher than that of the SC perforators and oblique branches. Flap necrosis occurred in seven cases (11.86%); sex, hypertension, diabetes mellitus, coronary artery disease, perforator course, and history of radiotherapy did not significantly affect flap necrosis. Conclusion: The ALT free flap procedure remains popular for reconstruction of the head and neck. In this study, we observed that the majority of cutaneous vessels supplying the flaps were MC perforators (87%). When using the MC perforator during flap elevation, careful dissection of the perforator is required to achieve successful ALT flaps because intramuscular dissection is difficult. Perforator pattern and history of radiotherapy did not affect flap necrosis.

해외 JIT에 수록된 운전경험 분석 (An Analysis of Operating Experience Reports on the Foreign JIT)

  • 이상훈;김제헌;송태영
    • 한국압력기기공학회 논문집
    • /
    • 제10권1호
    • /
    • pp.70-74
    • /
    • 2014
  • An Operating Experience Report(OER) has written about events and accidents happened at a Nuclear Power Plant(NPP). The purpose of publishing the OER is to prevent the similar event or accident repeatedly by spreading the experience of a single plant to other plants personnel. In this paper, it is analyses that the foreign NPPs' OERs on JIT published by the International Nuclear Agency(WANO, INPO, COG, BE). The analysis introduced in this paper is performed along with the various factors such as type of work, root-cause, and equipment. The root-cause analysis about the OERs shows that the Human-error is the major factor in foreign NPPs, but on the other hand equipment problem is the main part of the Domestic NPPs. The ratio of the foreign NPP's OERs on JIT according to the type of work was applied to KHNP-JIT developed nowadays for the first time in KOREA.