• 제목/요약/키워드: Biological systems

검색결과 2,235건 처리시간 0.031초

Antioxidant Properties of Water Extract from Acorn

  • Yin, Yu;Heo, Seong-Il;Jung, Mee-Jung;Wang, Myeong-Hyeon
    • Journal of Applied Biological Chemistry
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    • 제50권2호
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    • pp.70-73
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    • 2007
  • Antioxidant and anti-diabetic activities of acorn were evaluated by its potential for scavenging stable DPPH free radical, inhibition of lipid peroxidation, reducing power, and inhibiton of ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water extract of acorn exhibited strong antioxidant and antidiabetic related activities in the tested model systems. Solvent fractionation of the water extract revealed that the water fraction and the EtOAc fraction had strong antioxidant activity, and inhibitory activity on ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water fraction exhibited higher DPPH radical scavenging activity ($EC_{50}=7.19{\mu}g/mL$) than that of ${\alpha}-tocopherol\;(EC_{50}=7.59{\mu}g/mL)$. It is considered that water extract of acorn has the potential for natural antioxidant and anti-diabetic products.

환경 Stress에 의한 횐쥐뇨중 catecholamine의 변화 (Variations of Catecholamine Contents in Rat Urine by Environmental Stress)

  • 김형석
    • Environmental Analysis Health and Toxicology
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    • 제3권3_4호
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    • pp.9-15
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    • 1988
  • The word of stress crime from Latin language as stringere and it was used in medical fields from 1935. According to Selye, all the biological bodies reveal physilolgical changes when some stimulation exceed normal levels, and consequently the pituitary gland and adrenal systems are activated. Jacob expressed that stress is the loss of homeostasis by physical, chemical, and emotional stimulation. When biological organisms receive extreme stress the amount of catecholamine excretion are increase. Author investigated the catecholamine contents in rat urine after giving the low temperature stress, noise stress, and water immersion stress. The 24 hours rat urine was collected by adding 1 ml 6 N-HCl and the sample is passed through Bio-Rex 70 samples treatment column to extract catecholamine and detected the catecholamine with HPLC-fluorescence detetor. The highest epinephrine concentration was 67.14 ng in water immersion stress condition and the dopamine concentration of 221.37 ng was shown in the low temperature stress condition.

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길항세균 Bacillus subtilis YBL-7 건조포자체의 종자피막화에 의한 생물학적 방제 (Seed Coating for the Application of Biocontrol Agent Bacillus subtilis YBL-7 against Phytopathogens)

  • 장종원;김상달
    • 한국미생물·생명공학회지
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    • 제23권2호
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    • pp.243-248
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    • 1995
  • Agrochemicals for the plant-disease control are criticized severely for causing environmental pollution and residual problems, and consequently microbial disease control agents are expected to be safer and more economical for sustainable agriculture. Treatment of biological control agents to seed requires the use of effective delivery systems that allow full expression of the benefical qualities of the bioprotectant. For the activation and establishment of bioprotectant around the plant seed which are able protect the seeds and seedlings from pathogen attack, the optimal liquid coating formulation was obtained using 2% sodium carboxymethyl cellulose (binder), 20% sesame dregs (solid particulate material), and dried spore of Bacillus subtilis YBL-7 (bioprotectants, 10 mg/g of seed). Suppressive of root rot was demonstrated in pot trials with coated kidney bean (Phaseolus vulgaris L.) seeds. Coated seeds with B. subtilis YBL-7 spore in F. solani-infested soil reduced disease incidence by 85% to 90% after 30 days.

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Speckle Reduction in the Wavelet Domain for Image with Optical Coherence Tomography

  • Chang, Ju-Wan;Lee, Chang-Su;Na, Ji-Hoon;Paes, Stephane;Lee, Byeong-Ha
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.2459-2463
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    • 2005
  • Optical coherence tomography (OCT) is high resolution medical imaging system which is obtaining image inside biological objects with non-destructive method. OCT system is based on Michelson interferometer with a reciprocating mirror in the reference arm and a biological object in the sample arm. The obtained OCT image suffers from a granular or mottled image, called speckle. Speckle is caused by random interferences between reflected coherence waves. In this paper, we propose effective speckle reduction method that uses wavelet transform. With wavelet domain image, sub-windowing and thresholding are performed. Finally, speckle reduction experiments for Misgurnus mizolepis skin and rat eye images are shown.

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Two New Species of the Halichondriidae(Demospongiae: Halichondrida) from Korea

  • Kang, Dong-Won;Sim, Chung-Ja
    • Animal cells and systems
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    • 제12권1호
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    • pp.61-64
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    • 2008
  • Two new marine species of the family Halichondriidae, Ciocalypta sasuensis n. sp. and Epipolasis maraensis n. sp., are collected from Chujado Island and Jejudo Island, Korea during 2000-2005. Ciocalypta sasuensis n. sp. is closely related to C. penicillus(Bowerbank, 1864) in the type of shape and ectosomal skeleton. However, C. sasuensis n. sp. is larger than Ciocalypta penicillus. Epipolasis maraensis n. sp. is similar to E. suluensis(Wilson, 1925) in the type of skeleton, but is different in size of spicule and growth form. Its oxeas and raphide are smaller than E. suluensis's. The growth form of this new species is semispherical and massive, but E. suluensis is lamellated.

Two New Sponges of the Genus Halichondria(Halichondrida: Halichondriidae) from Korea

  • Kang, Dong-Won;Sim, Chung-Ja
    • Animal cells and systems
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    • 제12권1호
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    • pp.65-68
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    • 2008
  • Two new marine sponges in the family Halichondriidae, Halichondria gageoenesis n. sp. and Halichondria muanensis n. sp. are collected from Gageodo Island and Yongjeong-ri, Hyeongyeong-myeon, Muan-gun, Korea during 2006-2007. H. gageoenesis n. sp. is similar to H. oshoro(Tanita, 1961) in type of spicule, but is different from the latter in growth form and size of spicule. The oxea of the new species is larger than H. oshoro's. The growth form of H. gageoenesis n. sp. is thick and consists of encrusting with numerous erect hollow cylindrical tubes, but H. oshoro is of massive form. H. muanensis n. sp is similar to H. retiderma(Dendy, 1921) in type of spicule and choanosomal skeleton, but it is different from the latter in growth form and size of spicule. The oxea is smaller than that of H. retiderma. The growth form is thick and consists of encrusting, with numerous erect hollow cylindrical tubes, compared with the massive lobose of H. retiderma.

Copying and Manipulating Nature: Innovation for Textile Materials

  • Rossbach, Volker;Patanathabutr, Pajaera;Wichitwechkarn, Jesdawan
    • Fibers and Polymers
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    • 제4권1호
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    • pp.8-14
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    • 2003
  • This paper considers the potential impact of biological approaches such as bio-copying (biomimetics) and biomanipulating (e.g. genetic engineering) on future developments in the field of textiles and, in particular, fibres. If analytical tools for studying biological systems combined with those of materials science are further developed, and higher efficiency and reproducibility of genetic engineering technology can be achieved, the potential for the copying and manipulation of nature for textile innovations will be immense. The present state for both fields is described with examples such as touch and close fastener, structurally coloured fibres, the Lotus of lect (for bio-copying), as well as herbicide tolerant cotton, insecticide resistant cotton (Bt cotton), cotton polyester bicomponent fibres, genetically engineered silkworm and silk protein, and spider fibres. (for genetic engineering).

Island ecology on biological-cultural diversities and human adaptation in seascapes

  • Hong, Sun-Kee
    • Journal of Ecology and Environment
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    • 제33권2호
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    • pp.115-120
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    • 2010
  • The Asian cultural landscape is a mirrored ecosystem of great complexity, formed by the interaction of man and nature, coupled with a host of ecological processes. The human dependencies on and environmental adaptation of the bio-organisms and the surrounding landscape constitute the typical cultural landscape. Islands are a good example of a cultural landscape, and each mosaic pattern of marine and coastal ecosystems reflects bio-cultural diversity. Along with land-use patterns, wise use of biological organisms and indigenous knowledge has expanded to islands in the Asia-Pacific region in several ways (sea current and human impact, etc.). Loss in biodiversity and landscape diversity as well as cultural diversity owing to global warming and rapid urbanization are emerging issues for island ecosystems all over the world. In order to sustain the historical coexistence between man and natural systems, we ecologists must continue to search for a holistic solution for academic consilience. In this paper, I present the vision and practical characteristics of island ecology with a view toward the conservation of the traditional landscape and bio-cultural diversities in the seascape.

A Self-Recognition Algorithm based Biological Immune System

  • Sim, Kwee-Bo;Lee, Dong-Wook;Sun, Sang-Joon;Shim, Jae-Yoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.115.1-115
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    • 2001
  • According as many people use a computer newly, damage of computer virus and hacking is rapidly increasing by the crucial users. A computer virus is one of program on computer and has abilities of self reproduction and destruction like a virus of biology. And hacking is to rob a person´s data in a intruded computer and to delete data in a person´s computer from the outside. To block hacking that is intrusion of a person´s computer and the computer virus that destroys data, a study for intrusion-detection of system and virus detection using a biological immune system is in progress. In this paper, we make a mood of positive selection and negative selection of self-recognition process that is ability of ...

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A Molecular Approach to Mitophagy and Mitochondrial Dynamics

  • Yoo, Seung-Min;Jung, Yong-Keun
    • Molecules and Cells
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    • 제41권1호
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    • pp.18-26
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    • 2018
  • Mitochondrial quality control systems are essential for the maintenance of functional mitochondria. At the organelle level, they include mitochondrial biogenesis, fusion and fission, to compensate for mitochondrial function, and mitophagy, for degrading damaged mitochondria. Specifically, in mitophagy, the target mitochondria are recognized by the autophagosomes and delivered to the lysosome for degradation. In this review, we describe the mechanisms of mitophagy and the factors that play an important role in this process. In particular, we focus on the roles of mitophagy adapters and receptors in the recognition of damaged mitochondria by autophagosomes. In addition, we also address a functional association of mitophagy with mitochondrial dynamics through the interaction of mitophagy adaptor and receptor proteins with mitochondrial fusion and fission proteins.