• 제목/요약/키워드: The volume of delivery

검색결과 294건 처리시간 0.046초

Neuroradiology 연구를 위한 VX2 세포를 이용한 토끼 뇌종양 모델 제작과 MRI를 이용한 검증 (Development of Rabbit Brain Tumor Model Using VX2 Cells and Verification with the MRI in Neuroradiologic Research)

  • 김용우;최선희;김학진
    • 대한영상의학회지
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    • 제84권2호
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    • pp.441-453
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    • 2023
  • 목적 네 가지 방법으로 토끼의 뇌에 VX2 세포를 이식하여 뇌종양의 생성 유무와 위치, 체적을 분석하고자 한다. 대상과 방법 공여 토끼를 희생하여 얻은 VX2 세포 현탁액을 1) 당일 이식, 2) 냉장 보관 7일 후 이식, 3) 초저온 냉동보관 7일 후 이식, 그리고 4) 공여 토끼를 희생하지 않고 조직생검 기구를 이용하여 VX2 세포현탁액을 얻은 후 당일 이식하였다. 뇌 이식에는 정위 기구를 사용하였으며 하방 레버를 이용하여 5 mm 진입하여 VX2 세포 현탁액을 주입하였다. 10일 경과 후 MR imaging을 실시하였으며 다음 날 뇌 조직을 얻어 조직검사를 실시하여 MR 영상과 현미경 검사상 뇌종양의 생성 유무와 위치, 체적 등을 살펴보았다. 결과 VX2 세포 현탁액을 당일 이식한 토끼(n = 18)에서는 17마리(94.4%)에서 뇌종양이 생겼다(평균 체적은 106.32 mm3). 냉장 보관 후 7일에 세포 현탁액을 만들어 뇌 이식한 토끼(n = 5)에서는 1마리(20%)에서 뇌종양이 생겼으나 현미경으로만 확인되었다. 초저온 냉동 보관 후 7일에 세포 현탁액을 만들어 뇌 이식한 토끼는 5마리에서는 3마리(60%)에서 뇌종양이 생겼고 현미경으로만 확인되었다. 생검 횟수를 10회 실시한 후 이식한 3마리에서는 뇌종양이 생기지 않았고, 20회 실시한 후 이식한 2마리에서는 모두 뇌종양이 생겼으며 MR 영상과 조직검사에서 확인되었다(평균 체적 38.71 mm3). 네 가지 방법으로 발생한 종양의 위치는 superficial cortex가 대부분이었다. 결론 VX2 세포를 이식하여 토끼의 뇌종양 모델을 제작하는 기법은 쉽고 재현성은 다양했다. 이 모델은 뇌종양에 대한 영상, 치료 방법, 중재 시술 및 약물 전달 등 다양한 연구에 활용될 수 있을 것이다. 연구자의 처한 다양한 환경에 따라 다양한 방법으로 VX2 세포를 이식할 수 있을 것으로 생각된다.

간암 환자의 세기조절방사선치료 시 호흡에 의한 움직임 조건에서 측정된 조사면 별 선량결과를 기반으로 재계산한 체내 선량분포 평가 (Evaluation of Dose Distributions Recalculated with Per-field Measurement Data under the Condition of Respiratory Motion during IMRT for Liver Cancer)

  • 송주영;김용협;정재욱;윤미선;안성자;정웅기;남택근
    • 한국의학물리학회지:의학물리
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    • 제25권2호
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    • pp.79-88
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    • 2014
  • 내부표적체적을 기반으로 계획된 간암 환자의 세기조절방사선치료에서 호흡에 의한 장기의 움직임 영향을 적용하여 체내 실제 종양 부피와 중요 장기 부피에서의 선량분포를 재계산하고, 호흡동조 방식의 세기조절방사선치료 계획 결과와 비교를 통한 선량적 특성을 분석하였다. 내부표적체적은 MIM 프로그램을 사용하여 형성하였고, 호흡에 의한 장기 움직임을 모사할 수 있는 구동 팬텀을 사용하였다. 체내 선량분포는 세기조절방사선치료의 품질보증 과정에서 2차원 다이오드 검출기 배열 장치인 MapCHECK2로 측정한 조사면 별 측정 결과를 기반으로 3DVH 프로그램으로 재계산 하였다. 내부표적체적 기반의 세기조절방사선치료 수행 시 계획표적체적에 충분히 처방선량이 조사되었지만, 선량의 균일도는 호흡동조 방식의 세기조절방사선치료와 비교 시 열등한 결과를 보였다. 상대적으로 더 큰 조사면을 사용하는 내부표적체적 기반의 세기조절방사선치료에서 손상위험장기체적에 더 높은 선량이 조사됨을 확인할 수 있었지만, 척수에 증가된 선량은 부작용 발생확률에 큰 영향을 주지 않는 적은 양이었고, 정상 간이나 신장 부위의 증가된 선량도 최적화 과정에서 좀 더 선량감소 조건을 강화한다면 큰 영향이 없을 것으로 평가되었다. 호흡동조 방식의 세기조절방사선치료가 치료계획에서는 더 좋은 선량분포를 보이고 있으나, 실제 구현 과정에서 다엽콜리메이터의 움직임 오류로 인한 선량의 오차와 치료시간의 증가 측면의 단점이 있으므로, 환자 호흡 상태 및 손상위험장기의 선량제한 값에 대한 사전 분석을 통해 환자 별 최적의 세기조절방사선치료 기법을 선정하여 적용하는 것이 타당하다고 생각된다.

빅데이터와 AI를 활용한 의료영상 정보 시스템 발전 방향에 대한 연구 (A Study on the Development Direction of Medical Image Information System Using Big Data and AI)

  • 유세종;한성수;전미향;한만석
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제11권9호
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    • pp.317-322
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    • 2022
  • 정보기술의 급격한 발달은 의료 환경에서도 많은 변화를 가져오고 있다. 특히 빅데이터와 인공지능(AI)을 활용한 의료영상 정보 시스템의 빠른 변화를 견인하고 있다. 전자의무기록(EMR)과 의료영상저장전송시스템(PACS)으로 구성된 처방전달시스템(OCS)은 의료 환경을 아날로그에서 디지털로 빠르게 바꾸어 놓았다. PACS는 여러 솔루션과 결합하여 호환, 보안, 효율성, 자동화 등 새로운 발전 방향을 보여주고 있다. 그 중, 영상의 질적 개선을 할 수 있는 빅데이터를 활용한 인공지능(AI)과의 결합이 활발히 진행되고 있다. 특히 딥러닝 기술을 활용하여 의료 영상 판독을 보조할 수 있는 시스템인 AI PACS가 대학과 산업체의 협력으로 개발되어 병원에서 활용되고 있다. 이처럼 의료 환경에서 의료영상 정보 시스템의 빠른 변화에 맞추어 의료시장의 구조적인 변화와 이에 대처할 수 있는 의료정책의 변화도 필요하다. 한편, 의료영상정보는 디지털 의료영상 전송 장치에서 생성되는 DICOM 방식을 기본으로 하고, 생성하는 방법의 차이에 따라 Volume 영상, 단면 영상인 2차원적 영상으로 구분된다. 또한, 최근 많은 의료기관에서는 스마트 병원 서비스를 내세우며 차세대 통합 의료정보시스템의 도입을 서두르고 있다. 차세대 통합 의료정보시스템은 EMR을 바탕으로 전자동의서, AI와 빅데이터를 활용한 정밀의료, 외부기관 등을 통합한 솔루션으로 구축하며, 이를 바탕으로 환자 정보 DB 구축과 데이터의 표준화를 통한 의료 빅데이터 기반의 의학 연구를 목적으로 한다. 우리나라의 의료영상 정보 시스템은 앞선 IT 기술력과 정부의 정책에 힘입어 세계적인 수준에 있으며, 특히 PACS 관련 프로그램은 의료 영상정보 기술에서 세계로 수출을 하고 있는 한 분야이다. 본 연구에서는 빅데이터를 활용한 의료영상 정보 시스템의 분석과 함께 의료영상 정보 시스템이 국내에 도입되게 된 역사적 배경을 바탕으로 현재의 흐름을 파악하고 나아가 미래의 발전 방향을 예측하였다. 향후, 20여 년 동안 축적된 DICOM 빅데이터를 기반으로 AI, 딥러닝 알고리즘을 활용하여 영상 판독률을 높일 수 있는 연구를 진행하고자 한다.

흑색종에서의 I-131표지 혈관내피세포성장인자 수용체2항체를 이용한 방사면역치료 평가 (Evaluation of the Radioimmunotherapy Using I-131 labeled Vascular Endothelial Growth Factor Receptor2 Antibody in Melanoma Xenograft Murine Model)

  • 김은미;정환정;박은혜;정수진;이창문;장규윤;김동욱;임석태;손명희
    • Nuclear Medicine and Molecular Imaging
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    • 제42권4호
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    • pp.307-313
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    • 2008
  • 목적: 혈관내피성장인자(VEGF)와 그 수용체는 종양의 성장과 전이에 매우 중요한 역할을 한다 3개의 수용체가 알려져 있는데 그 중에서도 VEGFR2 (Flk-1/KDR)가 종양 angiogenesis에 매우 밀접하게 관련한 것으로 알려져 있다. 본 연구에서는 마우스 Flk-1 항체로 알려진 DC101에 I-131을 표지하여 매우 공격적인 종양으로 알려진 흑색 종의 치료 정도를 확인해 보고자 하였다. 방법: 하이브리도마 세포에서 Flk-1 항체인 DC101을 분리하여 western blot, ELISA, maldi-tof 방법을 이용하여 순도를 확인하고 항체 에 chloramin T를 이용하여 I-131을 표지하였다. 누드마우스에 B16F10세포를 주사하여 흑색종 모델을 만들고 평균 $200-250\;mm^3$으로 키워 $^{131}I$-DC101을 주사하여 영상과 시간별 장기섭취율(%ID/g)을 비교하고, 종양내 Flk-1 발현을 확인하기 위하여 면역염색 등을 시행하였다. 흑색종 동물모델을 5개 군으로 나누어 각각 치료를 시행하였다. 1군은 PBS만을, 2군은 $^{131}I$-DC101 $50\;{\mu}g(200\;{\mu}Ci)$을, 3군은 DC101 $50\;{\mu}g$을, 4군은 $^{131}I$-DC101 $30\;{\mu}g(200\;{\mu}Ci)$을, 5군은 $^{131}I$-DC101 $15\;{\mu}g(200\;{\mu}Ci)$을 각각 매 3일 ${\sim}$ 4일마다 주사하고 전체 5회를 주사하였고 종양볼륨을 측정하였다. 결과: $^{131}I$-DC101을 흑색종 모델에 정맥주사하고 78시간까지 영상을 얻은 결과 시간에 따라 종양섭취가 증가 하는 영상을 보였다. 시간대별 장기섭취를 정확히 확인하기 위하여 1시간, 6시간, 24시간, 48시간, 72시간 장기섭취율을 비교한 결과 시간에 따라 혈액내 방사능치가 서서히 감소하였고 다른 장기의 섭취도 시간에 따라 감소하였고 종양의 섭취는 48시간까지 증가하였다가 그 이후는 감소하였다. 흑색종 동물모델에 $^{131}I$-DC101 치료를 시행한 결과 3번째 주사까지는 각군간의 유의한 차이를 보이지 않다가 4번째 주사를 시행한 때부터 1군과 2군, 또는 1군과 4군간의 유의한 차이를 보이기 시작했다. 또한 5번째 주사 이후에는 5군에서도 유의한 차이를 보여 I-131 에 의한 효과가 뚜렷해짐을 확인하였다. 결론 마우스 Flk-1 항체로 알려진 DC101을 흑색종 모델에 정맥내 주사하였을 때, 종양성장억제 효과를 보이지 않는 항체양에서도 I-131을 표지하여 치료를 시행했을 경우에는 효율적인 종양성장억제 효과를 보였다.

일개 대학병원의 환자군별 진료서비스 변이와 포괄수가제 적용에 따른 진료수익 변화 (Studies on the variations of hospital use and the changes in hospital revenues of 10 KDRGs under the PPS)

  • 전기홍;송미숙
    • 보건행정학회지
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    • 제7권1호
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    • pp.100-124
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    • 1997
  • In order to suggest the strategies for participation in the PPS(Prospective Payment System), analyses were performed based on variations in utilization pattern and changes in revenues of hospitals in 10 selected KDRGs. The data was collected from the claims data of a tertiary hospital in Kyunggido from September 1, 1995 to August 31, 1996. The studies consisted of 1, 718 inpatients diagnosed for lens procedures, tonsilectomy &/or adenoidectomy, appendectomy with complicated principal diagnosis, Cesarean section, or vaginal delivery without any complications. The resources used in each KDRG were measured including average length of stay, total charges, number of orders, intensity of medical services, frequencies of medical services, the rate of non-reimbursable charges, and the rate of non-reimbursable orders. Then, the changes in hopital revenues due to the composition of medical fee schedules under the PPS were estimated as follows: 1) The variations in average lenght of stay, total charges, number of orders, the intensity of medical services, the frequency of medical services, the rate of non-reimbursable charges, and the rate of non-reimbursable orders among the 10 KDRGs were comparatively small. 2) The average lenght of stay was the longest(6.0 days) for appendectomy with complicated principal diagnosis, while it was the shortest(2.1 days) for two vaginal deliveries. Statistically differences existed in the average length of stay among physicians and among the dates of admission in several KDRGs. 3) The total charges were the highest for lens procedures(1, 716, 000 won), while the lowest charges were for two vaginal deliveries(558, 000 won). Statistically differences in the total charges were found among physicians in several KDRGs: however, there were no differences with the dates of admission. 4) The number of orders was the greatest(155) for appendectomy with complicated principal diagnosis, while it was the smallest(75) for the two vaginal deliveries. Statistical differences in the number of orders did not exist among physicians in the KDRGs. 5) Significant differences were found in the intensity of medical services, and in the frequency of medical services among physicians in the KDRGs. 6) The rate of non-reimbursable charges for each KDRG was not related to the rate of non-reimbursable orders. The rate of non-reimbursable orders was the highest(36.0%) for lens procedures, while the lowest rate(11.6%) was for appendectomy with complicated principal diagnosis. The rate of non-reimbursable charges was the highest(39.4-39.7%) for vaginal deliveries, while the lowest rate(13.1%) was for tonsillectomy &/or adenoidectomy(<17 ages). 7) If the physician's practicing style were not change under the PPS, the hospital revenuses could be increased by 10%, and the portion of patient payment could be decreased by 1.4-22.4%. However, the non-reimbursable charges for showed little change between two reimbursement systems. Based upon the above findings, this hospital could be eligible for participation in the PPS(Prospective Payment Systm). However, the process of diagnosis and treatment should be standardized, inentifying methods to reduce cost and to assure quality of medical care. Furthermore, consideration should be given to finding ways to increase patient volume.

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Dose Verification of Intensity Modulated Radiation Therapy with Beam Intensity Scanner System

  • Vahc, Young-Woo;Park, Kwangyl;Ohyun Kwon;Park, Kyung-Ran;Lee, Yong-Ha;Yi, Byung-Yong;Kim, Sookil
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.248-251
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    • 2002
  • The intensity modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation treatment of patients. Patient dose verification is clinically one of the most important parts in the treatment delivery of the radiation therapy. The three dimensional (3D) reconstruction of dose distribution delivered to the target helps to verify patient dose and to determine the physical characteristics of beams used in IMRT. A new method is presented for the pretreatment dosimetric verification of two dimensional distributions of photon intensity by means of Beam Intensity Scanner System (BISS) as a radiation detector with a custom-made software for dose calculation of fluorescence signals from scintillator. The scintillator is used to produce fluorescence from the irradiation of 6MV photons on a Varian Clinac 21EX. The BISS reproduces 3D- relative dose distribution from the digitized fluoroscopic signals obtained by digital video camera-based scintillator(DVCS) device in the IMRT. For the intensity modulated beams (IMBs), the calculations of absorbed dose are performed in absolute beam fluence profiles which are used for calculation of the patient dose distribution. The 3D-dose profiles of the IMBs with the BISS were demonstrated by relative measurements of photon beams and shown good agreement with radiographic film. The mechanical and dosimetric properties of the collimating of dynamic and/or step MLC system alter the generated intensity. This is mostly due to leaf transmission, leaf penumbra and geometry of leaves. The variations of output according to the multileaf opening during the irradiation need to be accounted for as well. These phenomena result in a fluence distribution that can be substantially different from the initial and calculative intensity modulation and therefore, should be taken into account by the treatment planning for accurate dose calculations delivered to the target volume in IMRT.

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해외투자(海外投資)와 지속가능발전 원칙 - 적도원칙(赤道原則)(Equator Principles)을 중심으로 - (How to Reflect Sustainable Development in Overseas Investment including Equator Principles)

  • 박훤일
    • 한국무역상무학회:학술대회논문집
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    • 한국무역상무학회 2006년도 제35회 하계 정기세미나
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    • pp.45-72
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    • 2006
  • The Equator Principles are a set of voluntary environmental and social guidelines for ethical project finance. These principles commit banks and other signatories to not finance projects that fail to meet these guidelines. The principles were conceived in 2002 on an initiative of the International Finance Corporation and launched in 2003. Since then, dozens of major banks have adopted the Principles, and with these banks among them accounting for more than three quarters of all project loan market volume the Principles have become the de facto standard for all banks and investors on how to deal with potential social and environmental effects of projects to be financed. While regarding the Principles an important initiative, NGOs have criticised the Principles for not producing real changes in financing activities and for allowing projects to go through that should have been screened out by the Principles, such as the Sakhalin-II oil and gas project in Russia. In early 2006, a process of revision of the principles was begun. The Equator Principles state that endorsing banks will only provide loans directly to projects under the following circumstances: - The risk of the project is categorized in accordance with internal guidelines based upon the environmental and social screening criteria of the International Finance Corporation (IFC). - For all medium or high risk projects (Category A and B projects), sponsors complete an Environmental Assessment, the preparation of which must meet certain requirements and satisfactorily address key environmental and social issues. - The Environmental Assessment report addresses baseline environmental and social conditions, requirements under host country laws and regulations, applicable international treaties and agreements, sustainable development and use of renewable natural resources, protection of human health, cultural properties, and biodiversity, including endangered species and sensitive ecosystems, use of dangerous substances, major hazards, occupational health and safety, fire prevention and life safety, socio-economic impacts, land acquisition and land use, involuntary resettlement, impacts on indigenous peoples and communities, cumulative impacts of existing projects, the proposed project, and anticipated future projects, participation of affected parties in the design, review and implementation of the project, consideration of feasible environmentally and socially preferable alternatives, efficient production, delivery and use of energy, pollution prevention and waste minimization, pollution controls (liquid effluents and air emissions) and solid and chemical waste management. - Based on the Environmental Assessment, Equator banks then make agreements with their clients on how they mitigate, monitor and manage those risks through an 'Environmental Management Plan'. Compliance with the plan is required in the covenant. If the borrower doesn't comply with the agreed terms, the bank will take corrective action, which if unsuccessful, could ultimately result in the bank canceling the loan and demanding immediate repayment. - For risky projects, the borrower consults with stakeholders (NGO's and project affected groups) and provides them with information on the risks of the project. - If necessary, an expert is consulted. The Principles only apply to projects over 50 million US dollars, which, according to the Equator Principles website, represent 97% of the total market. In early 2006, the financial institutions behind the Principles launched stakeholder consultations and negotiations aimed at revising the principles. The draft revised principles were met with criticism from NGO stakeholders, who in a joint position paper argued that the draft fails by ignoring the most serious critiques of the principles: a lack of consistent and rigorous implementation.

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신맛(酸味)이 용혈성 빈혈흰쥐의 혈액성분에 미치는 효과 - 여성빈혈의 간호중재개발을 위한 동물실험 - (Effects of Sour Tastes on Blood Components in Anemic mice - Animal Experiment for Nursing Intervention of Female Anemia -)

  • 신혜숙;김상우
    • 대한간호학회지
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    • 제31권2호
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    • pp.268-278
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    • 2001
  • Many women in the world have suffered from anemia produced by menstruation, pregnancy and delivery. In the theory of oriental medicine, a sour taste is believed to have a tonic effect on the blood. Thus this paper is to investigate the effect of sour tastes on the improvement in anemia-induced female mice, using citric acid and Fructus schizandrae(五味子). The method used in this experiment was the change of RBC, WBC, Hemoglobin, Hematocrit, Fe, and TIBC in the blood of female mice who were fed citric acid and Fructus schizandrae(五味子). The results obtained were as follows ; 1. Compared with the control group (anemia- induced group without treatment), the mean number of RBC in the blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae (五味子) 500mg/kg. 2. Compared with the control group (anemia- induced group without treatment), the mean number of WBC in the blood of mice was not significantly larger in both sample groups fed citric acid and Fructus schizandrae(五味子). 3. Compared with the control group (anemia- induced group without treatment), the mean number of Hemoglobin in the blood of mice was significantly larger only in evaluating the change of the sample group fed Fructus schizandrae(五味子). 4. Compared with the control group (anemia- induced group without treatment), the mean percentage of Hematocrit in blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 3days. 5. Compared with control group (anemia- induced group without treatment), the mean volume of Fe in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg. 6. Compared with control group (anemia- induced group without treatment), the mean TIBC in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 7days. According to these results, a sour taste is presumed to have a general tonic effect on anemia, but more study must be taken on the effects of citric acid in improving female anemia.

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고흥지역 수산물 경매시장의 특성에 관한 연구 (A Study on the Auction Schemes of Fish Commodities in the Koheung Region)

  • 강연실
    • 수산경영론집
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    • 제29권2호
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    • pp.111-141
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    • 1998
  • Why are auctions so prevalent in fisheries fields\ulcorner One answer is, perhaps, that fisheries products have no standard value. The price of any catch of fish (at least of fish destined for the fresh fish market) depends on the demand and supply conditions at a specific moment of time, influenced by prospective market developments and prices must be remade for each transaction. There are various auction schemes including written-bid method in Korea. It is difficult to make decision the application of auction selling in market distribution. One reason is the absence of adequate data on which to base firm statements. There is very little precise information about the relative volume handled by auction scheme as compared with other sales schemes Because of the paucity reliable data, one must depend largely on qualitative in attempting to above this problem. This paper is designed to examine which auction scheme is more efficient as a economic tool by introducing the three auctions, as samples, utilized in Koheung peninsula. Koheung coast with abundant fisheries resource, locates on the Middle-South part in Korea and has three auction firm operating by fisheries cooperatives. fur selling of dry fish included sea weed, live fish and fresh fish respectively, As a result, 1 found that there are three interesting auction schemes as follow : 1. More than one winners are selected as buyers. The highest bidder can at first get fishes he wants to buy, second winner can get surplus fishes after the highest bidder employes one's privilege with the highest pay, and next winner would be a buyer if fishes would be left in sequence after being sold with higher price. Every fisherman can sell one' s fishes with equal unit price if he delivery it to the winner within one day. Therefore, all the vendors feel they are equal members of fisheries cooperation. 2. Written-bid pricing on the cover of handy book. It is easy to write and to erase the figure more than on the small black board, and is convenient also to keep in the pocket. 3. Auctioning on the fixed platform with fixed fish tank is a very fast auction scheme in spite of short displaying time. Auctioneer presides bidding at one place on the fixed platform, instead of moving, vendors should carry a container of live fishes in the fish tank into showing table in front of would-be buyers and auctioneer. Although the applicability of the auction system to a marketing problem depends in part on subjective considerations by those making decision, basically it is a matter of comparative economic efficiency. In general, if the scheme maximizes returns in relation to the effort expanded by both buyers and sellers, it will be utilized. If it does not, a more efficiency may take place over a period of time, but, even more important, those making decisions may become aware of the potentialities of new schemes. Therefore, in order to applicate the three interesting auction schemes introduced in this paper to other fisheries market, it is necessary not only to analyze many other auction schemes but also to compare the economic efficiency those schemes utilizing in other fisheries market.

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테트라싸이클린 및 테트라싸이클린-구연산 혼합젤로 처리한 치근면의 항 미생물 활성 변화에 관한 연구;In Vivo Study (Antimicrobial Activities of Root Surfaces Treated with Tetracycline-containing gel and a Mixture of tetracycline and citric acid-containing gel;in vivo study)

  • 정희선;한수부;남석우;심창구;계승범
    • Journal of Periodontal and Implant Science
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    • 제27권1호
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    • pp.79-90
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    • 1997
  • The purpose of this study was to evaluate the substantivity of experimentally developed gel type tetracycline HCl and a mixture of tetracycline-citric acid gel, and compare to those of solution type tetracycline HCl. 11 extracted anterior teeth were subjected to this study. After scaling and root planing teeth were randomly divided into 3 treatments groups : group 1; 3 teeth were irrigated with tetracycline HCl(50mg/ml) solution , group 2; tetracycline gel (5%) was inserted in the periodontal pockets of 3 teeth, group 3; a mixture of tetracycline and citric acid gel was inserted in the pockets of 3 teeth. And 2 teeth treated in 0.9 % sterile saline served as controls. After 5-minute exposure, each tooth immediately extracted and incubated at room temperature for 22 days in tris-buffered saline as a desorption media. The total volume of TBS was removed and replaced with fresh TBS, at 24-h intervals. Removed desorption media transferred to a sterile vial and stored at -70 oC. This procedure was repeated every 24 h throughout the 22-day desorption period. Using Porphyromonas gingivalis as an indicator organism, a microtiter assay was used to evaluate antimicrobial activity desorbed from the teeth. 1. 50mg/ml tetracycline HCl solution exhibited the longest antimicrobial activity. Compared to saline treated group, it showed significant difference on the day 1 and day 2 desorption period. 2. The ODs of 5% tetracycline gel and a mixture of tetracycline-citric acid gel were significantly different during the first 24 hour only. 3. There was no statistically significant difference after the day 3 between the groups.(p<0.05). Despite our expectation a mixture of tetracycline-citric acid gel did not show longer antimicrobial activities than those of tetracycline gel, and the solution type exhibited the longest activities. Because the gel type agents may stay in the subgingival environment longer than the solution, if the teeth were not extracted immediately after the delivery of the agent, the result could be different. hus this result suggests the possibilities of practical use of these kind of gel type agents.

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