• Title/Summary/Keyword: biodynamics

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Biodynamic understanding of mercury accumulation in marine and freshwater fish

  • Wang, Wen-Xiong
    • Advances in environmental research
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    • v.1 no.1
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    • pp.15-35
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    • 2012
  • Mercury (Hg) is a global environmental pollutant that has been the cause of many public concerns. One particular concern about Hg in aquatic systems is its trophic transfer and biomagnification in food chains. For example, the Hg concentration increases with the increase of food chain level. Fish at the top of food chain can accumulate high concentrations of Hg (especially the toxic form, methylmercury, MeHg), which is then transferred to humans through seafood consumption. Various biological and physiochemical conditions can significantly affect the bioaccumulation of Hg-including both its inorganic (Hg(II)) and organic (MeHg) forms-in fish. There have been numerous measurements of Hg concentrations in marine and freshwater fish worldwide. Many of these studies have attempted to identify the processes leading to variations of Hg concentrations in fish species from different habitats. The development of a biokinetic model over the past decade has helped improve our understanding of the mechanisms underlying the bioaccumulation processes of Hg in aquatic animals. In this review, I will discuss how the biokinetic modeling approach can be used to reveal the interesting biodynamics of Hg in fish, such as the trophic transfer and exposure route of Hg(II) and MeHg, as well as growth enrichment (the increases in Hg concentration with fish size) and biomass dilution (the decreases in Hg concentration with increasing phytoplankton biomass). I will also discuss the relevance of studying the subcellular fates of Hg to predict the Hg bioaccessibility and detoxification in fish. Future challenges will be to understand the inter- and intra-species differences in Hg accumulation and the management/mitigation of Hg pollution in both marine and freshwater fish based on our knowledge of Hg biodynamics.

The Neuroprotective and Neurotrophic Effects of Tremella fuciformis in PC12h Cells

  • Park, Kum-Ju;Lee, Sang-Yun;Kim, Hyun-Su;Yamazaki, Matsumi;Chiba, Kenzo;Ha, Hyo-Cheol
    • Mycobiology
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    • v.35 no.1
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    • pp.11-15
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    • 2007
  • We examined the neuroprotective and neurotrophic effects of Tremella fuciformis. The neurotrophic effects of the hot water extract of T. fuciformis was evaluated by microscopically monitoring its potency to induce neurite outgrowth in PC12h cells. The hot water extract cf T. fuciformis promoted neurite outgrowth in PC12h cells in this study, superior to other natural substances which was reported previously. When cells were treated with the hot water extract of T. fuciformis prior to ${\beta}$-amyloid peptide treatment (active domain of A peptide $35{\sim}35$ treated), toxicity was significantly diminished (p<0.01). These results suggest that T. fuciformis might potentially be used as a precautionary agent in neurodegenerative disease, such as Alzheimer's disease, etc.

차량산업에서의 인체진동

  • 장한기
    • Journal of KSNVE
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    • v.12 no.2
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    • pp.113-119
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    • 2002
  • ‘인체진동(human vibration)’은 진동에 대한 인체의 반응(human response to vibration)의 줄임말로써, 환경으로서의 진동 및 충격이 인체에 미치는 물리적, 심리적 영향을 측정, 평가하는 것을 주요 연구대상으로 한다. 인체진동 분야의 주요 연구개발은 객관적인 물리량의 산출뿐만 아니라 주관적인 느낌을 수치화하는 작업을 포함하기 때문에 기계진동, 생체역학(biodynamics)과 기본적인 역학과 심리측정학(psychometrics), 심리물리학(psychophysics), 인간공학(ergonomics) 등과 같이 다양한 종류의 학문이 요구된다.(중략)

Fuzzy Modeling and Fuzzy Control of HIV-1 Biodynamics (HIV-1 바이오 동역학 모델의 퍼지 모델링 및 제어)

  • Kim Do-Wan;Ju Yeong-Hun;Park Jin-Bae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2006.05a
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    • pp.75-78
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    • 2006
  • 본 논문에서 우리는 HIV-1 바이오 동역학모델의 퍼지 모델링 및 디지털 퍼지 제어 기법을 소개한다. 그것의 제어구조는 샘플링 점들에서 측정한 상태로부터 현재 상태를 대략적으로 예측하는 수치적 적분 구조를 사용한다. 제안된 지능형 디지털 재설계에서는 전역 상태-정합과 안정도 조건들을 동시적으로 만족하는 타당한 디지털 제어 이득들을 찾는 것이다. 우리는 보상된 블록-펄스 함수를 이용하여 새로운 전역 상태-정합 조건을 우선 제시하며 그리고 나서 안정도 조건들을 이 조건들에 추가한다. 유도된 조건들은 선형행렬 부등식으로 묘사되며, 그로인해 볼록 최적화 문제로 쉽게 해결될 수 있다. 또한, 안정도 조건으로 인한 성능 하강을 방지하기 위해 두 단계 지능형 디지털 재설계 과정이 제안된다. 첫 번째 단계에서는 전역 상태-정합만을 고려한 디지털 제어 이득을 찾는다. 두 번째 단계에서는 얻어진 디지털 제어하의 폐루프 시스템을 안정화 시키는 추가디지털 제어기를 설계한다.

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The Neuroprotective and Neurotrophic Effects of Korean Gardenia (Gardenia jasminoides Ellis) in PC12h Cells

  • Park, Kum-Ju;Ha, Hyo-Cheol;Kim, Hyun-Su;Chiba, Kenzo;Yeo, Ik-Hyun;Lee, Sang-Yun
    • Food Science and Biotechnology
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    • v.15 no.5
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    • pp.735-738
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    • 2006
  • We examined the neuroprotective and neurotrophic effects of genipin fractionated from gardenia (Gardenia jasminoides Ellis) originating from Korea. The neurotrophic effects of the genipin containing fraction was evaluated by microscopically monitoring its potency to induce neurite outgrowth in PC12h cells. The genipin containing fraction from Korean gardenia promoted neurite outgrowth in PC12h cells in this study, similar to previously reported effects by Wako Chemical, Japan. When cells were treated with the genipin containing fraction prior to ${\beta}$-amyloid peptide treatment (active domain of A peptide 25-35 treated), toxicity was significantly diminished (p<0.0l). These results suggest that genipin prepared from Korean gardenia might potentially be used as a precautionary agent in neurodegenerative disease, such as Alzheimer's disease, etc.