• 제목/요약/키워드: Epidemic

검색결과 891건 처리시간 0.027초

AN SIRS EPIDEMIC MODEL ON A DISPERSIVE POPULATION

  • Ghosh, Asit K.;Chattopadhyay, J.;Tapaswi, P.K.
    • Journal of applied mathematics & informatics
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    • 제7권3호
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    • pp.925-940
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    • 2000
  • The spatial spread of a disease in an SIRS epidemic model with immunity imparted by subclinical infection on a population has been considered. The incidence rate of infection and the rate of immunization are both of nonlinear type. The dynamics of the infectious disease and its endemicity in local and global sense have been investigated.

효율적인 D2D 메시지 확산을 위한 최외곽 k개의 릴레이 선택 알고리즘 (Farthest-k relay selection algorithm for efficient D2D message dissemination)

  • 한세호;이호원
    • 한국정보통신학회논문지
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    • 제21권3호
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    • pp.543-548
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    • 2017
  • Epidemic 라우팅 프로토콜 기반의 메시지 확산 방식은 메시지를 수신한 기기들이 모두 릴레이를 수행하기 때문에 기기들의 전송 커버리지 중복으로 인한 메시지 중복 수신 문제가 빈번하게 발생한다. 따라서 본 논문에서는 이러한 문제점을 완화하기 위해 전송 범위 내에 존재하는 기기들 중 최외곽에 위치한 k개의 기기들만이 메시지 릴레이를 수행하는 최외곽 k개의 릴레이 선택 알고리즘을 제안하고 기존방식과 성능 비교분석을 수행한다. 포함 확률과 총 수신 메시지의 수 그리고 전송 효율에 대한 시뮬레이션 결과를 통해 제안 방안의 우수성을 증명한다.

국내 분리 돼지 유행성설사 바이러스 Chinju99주의 생물학적 및 물리화학적 성상 (Biological and Physicochemical Properties of Porcine Epidemic Diarrhea Virus Chinju99 Strain Isolated in Korea)

  • Lee, Hee-Kyung;Yeo, Sang-Geon
    • 한국임상수의학회지
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    • 제20권2호
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    • pp.150-154
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    • 2003
  • 진주 지역에서 1000 여두의 생후 1주령 포유 자돈군에 심한 설사증이 발생하였던바 소장조직으로부터 RNA를 추출한 후 reverse transcription-polymerase chain reaction을 실시하였던 결과, porcine epidemic diarrhea (PED) virus (PEDV)의 N 유전자가 검출되어 PED로 진단되었다. Trypsin (10ug/ml)을 첨가한 배지에서 Vero 세포를 배양하면서 장조직으로부터 바이러스 분리배양을 시도하였던 결과 2회의 blind passage 후에 PEDV를 분리할 수 있었다. 따라서 이 분리주를 Chinju99로 명명하였으며, Chinju99주의 생물학적 및 물리화학적 성상을 조사하였던 결론은 다음과 같다. Chinju99주는 전자현미경 소견에서 비정형의 타원형 입자로서 표면에 spike 구조를 가지고 있었으며, Vero 세포내 배양시에 점진적으로 원형변성, 합포체형성 등의 세포변성 소견을 나타내었다. 또한 20% ether, 5% chloroform에서 불안정하였으며 pH 4-7의 산성조건에서는 안정성을 나타내었다. 동시에 $50^{\circ}C$에서 180분간 처리 후에도 감염성이 유지되었고 sucrose 용액에서의 부유밀도가 1.180g/ml으로서, coronavirus의 전형적인 생물학적 및 물리화학적 성상을 나타내었다.

돼지 유행성 설사증 (Porcine Epidemic Diarrhea) 감염 소장상피세포의 전자현미경 관찰 (Ultrastructural Changes in Enterocyte infected with Porcine Epidemic Diarrhea Virus)

  • 박남용;구경본;김승재;정치영;박영석;조경오;김용환;임형호
    • 한국수의병리학회지
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    • 제3권1호
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    • pp.35-44
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    • 1999
  • The morphologic changes of small intestinal epithelium in pigs diagnosed as porcine epidemic diarrhea(PED} by virus isolation and immunohistochemistry were studied through light microscope and transmissible electron microscope. On semi-thin section, the histologic findings showed severe villous atrophy and fusion with hyperplasia of cuboidal epithelium in the villi, inflammatory cell infiltration in lamina propria, and increased mitotic figures in the crypt. The structural changes were mostly restricted to the cytoplasm of affected absorptive epithelium of villi. 3 types of epithelial changes were found; degenerated virus-affected cells, undifferentiated cuboidal cells, and normal columnar cells. On electron microscopy, round to spherical viral particles of 50∼l00nm in diameter were found within the dilated vesicles and endoplasmic reticulums of degenerated cells, which had decreased their cytoplasmic electron density due to dilated and missing organelles(e.g. mitochondria, ERs, etc.). Microvilli were shortened and sparse, leaving denuded terminal web of the villous epithelial cells. Fat globules were often found within slightly degenerated enterocytes. On the tip of villi, severely damaged cells were exfoliated and replaced by undifferentiated cuboidal cells We found distinct ultrastructural changes in the jejunal epithelium confirming PED virus infection is involved in malabsorptive diarrhea.

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Beyond SARS-CoV-2: Lessons That African Governments Can Apply in Preparation for Possible Future Epidemics

  • Oboh, Mary Aigbiremo;Omoleke, Semeeh Akinwale;Imafidon, Christian Eseigbe;Ajibola, Olumide;Oriero, Eniyou Cheryll;Amambua-Ngwa, Alfred
    • Journal of Preventive Medicine and Public Health
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    • 제53권5호
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    • pp.307-310
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    • 2020
  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed unprecedented pressure on healthcare systems, even in advanced economies. While the number of cases of SARS-CoV-2 in Africa compared to other continents has so far been low, there are concerns about under-reporting, inadequate diagnostic tools, and insufficient treatment facilities. Moreover, proactiveness on the part of African governments has been under scrutiny. For instance, issues have emerged regarding the responsiveness of African countries in closing international borders to limit trans-continental transmission of the virus. Overdependence on imported products and outsourced services could have contributed to African governments' hesitation to shut down international air and seaports. In this era of emerging and re-emerging pathogens, we recommend that African nations should consider self-sufficiency in the health sector as an urgent priority, as this will not be the last outbreak to occur. In addition to the Regional Disease Surveillance Systems Enhancement fund (US$600 million) provided by the World Bank for strengthening health systems and disease surveillance, each country should further establish an epidemic emergency fund for epidemic preparedness and response. We also recommend that epidemic surveillance units should create a secure database of previous and ongoing pandemics in terms of aetiology, spread, and treatment, as well as financial management records. Strategic collection and analysis of data should also be a central focus of these units to facilitate studies of disease trends and to estimate the scale of requirements in preparation and response to any future pandemic or epidemic.

돼지 유행성 설사 바이러스 (porcine epidemic diarrhea virus)의 국내 분리주 작성에 관한 연구 (Isolation of porcine epidemic diarrhea virus (PEDV) in Korea)

  • 권창희;권병준;정태성;기영진;허동호;황의경;이재진;안수환
    • 대한수의학회지
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    • 제33권2호
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    • pp.249-254
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    • 1993
  • 설사로 폐사한 자돈의 장 절편을 이용하여 돼지 유행성 설사바이러스(PEDV), 돼지 전염성 위장염 바이러스(TGEV), 돼지 로타 바이러스(PRV)에 대한 병인학적 검사를 형광항체반응을 통하여 조사하였던 바 돼지 유행성 설사 바이러스의 감염에 의한 자돈의 폐사를 확인하였다. 간접형광항체검사시 돼지 유행성 설사 바이러스에 대한 양성반응을 보인 가검재료를 이용 Vero세포에 연속 계대한 후 plaque assay를 통하여 크로닝된 돼지 유행성 설사 바이러스 KPEDV-9주를 작성하였다. 돼지 유행성 설사 바이러스에 대한 면역혈청과 바이러스가 분리된 농장에서 채취된 돼지 혈청을 이용 돼지 유행성 설사 바이러스에 대한 구조단백성분을 분석하였던 바 88K(M.W.), 74K, 70K, 58~54K, 54~46K, 44~40K 및 33~32K에 상당하는 단백성분을 검출할 수 있었다.

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『피역신방(辟疫神方)』의 독역(毒疫)에 대한 고찰 (A Study on 'Dokyeok(毒疫)' of Byeokyeoksinbang(辟疫神方))

  • 김상현;장우창;백유상;유정아;정창현
    • 대한한의학원전학회지
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    • 제28권2호
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    • pp.33-45
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    • 2015
  • Objectives : Through the study on Byeokyeoksinbang(辟疫神方), it would be expected to analyze Dokyeok(毒疫)'s characteristic and to comprehend how the changes in viewpoints of epidemic febrile disease were made. Methods : It has been done to analyze the original text of Byeokyeoksinbang(辟疫神方), and to compare the theory of Onbyeongjobyeon(溫病條辨) associated with the signature symptom of Dokyeok(毒疫). Results : Heo Jun(許浚) experienced a specific epidemic disease called 'Dokyeok(毒疫)', on which he made observations and analyzed its features and wrote Byeokyeoksinbang(辟疫神方). In Byeokyeoksinbang(辟疫神方), 'Dokyeok(毒疫)' is characterized by rash[疹], its pathogenesis is warm temperature, thus its treatment principle is removing interior and exterior heat. The book's pragmatic perspective is highly appreciated, as HeoJun improved and solidified existing medical knowledge up to date. In addition, Byeokyeoksinbang(辟疫神方) is significant in that it differentiated between macula[癍疹] and rash[疹], much earlier than the febrile disease school of the Qing dynasty. Conclusions : Between Byeokyeoksinbang(辟疫神方) and Onbyeongjobyeon(溫病條辨), there are differences in treatments and patterns of rash[疹]. Based on this, it will be able to compare each disease that is written in two books. And a study on comparing the development between epidemic febrile disease[瘟疫學] of the Joseon dynasty and febrile disease[溫病學] of the Qing dynasty will be carried out with a follow-up study.