• 제목/요약/키워드: fibrils

검색결과 132건 처리시간 0.032초

Protein Folding, Misfolding and Refolding of Therapeutic Proteins

  • Shin, Hang-Cheol
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제6권4호
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    • pp.237-243
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    • 2001
  • Substantial progress has been made towards understanding the folding mechanisms of proteins in virto and in vivo even though the general rules governing such folding events remain unknown. This paper reviews current folding models along with experimental approaches used to elucidate the folding pathways. Protein misfolding is discussed in relation to disease states, such as amyloidosis, and the recent findings on the mechanism of converting normally soluble proteins into amyloid fibrils through the formation of intermediates provide an insight into understanding the pathogenesis of amyloid formation and possible cules for the development of therapeutic treatments. Finally, some commonly adopted refolding strategies developed over the part decade are summarized.

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NON-HYDROSTATIC SUPPORT OF PLASMA IN THE SOLAR CHROMOSPHERE AND CORONA

  • Chae, Jong-Chul
    • 천문학회지
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    • 제43권3호
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    • pp.55-64
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    • 2010
  • We investigate how plasma structures in the solar chromosphere and corona can extend to altitudes much above hydrostatic scale heights from the solar surface even under the force of gravity. Using a simple modified form of equation of motion in the vertical direction, we argue that there are two extreme ways of non-hydrostatic support: dynamical support and magnetic support. If the vertical acceleration is downward and its magnitude is a significant fraction of gravitational acceleration, non-hydrostatic support is dynamical in nature. Otherwise non-hydrostatic support is static, and magnetic support by horizontal magnetic fields is the only other possibility. We describe what kind of observations are needed in the clarification of the nature of non-hydrostatic support. Observations available so far seem to indicate that spicules in the quiet regions and dynamic fibrils in active regions are dynamically supported whereas the general chromosphere as well as prorninences is magnetically supported. Moreover, it appears that magnetic support is required for plasma in some coronal loops as well. We suspect that the identification of a coronal loop with a simple magnetic flux tube might be wrong in this regard.

Silk Spinning Apparatuses in the Cribellate Spider Nurscia albofasciata (Araneae: Titanoecidae)

  • Park, Eun-Ah;Moon, Myung-Jin
    • Animal cells and systems
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    • 제13권2호
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    • pp.153-160
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    • 2009
  • The fine structural characteristics of the silk spinning apparatus in the titanoecid spiders Nurscia albofasciata have been examined by the field emission scanning electron microscopy (FESEM). This titanoecid spiders have a pair of medially divided cribella just in front of the anterior spinnerets, and the surface of the cribellum is covered by hundred of tiny spigots which produce numerous cribellate silk fibrils. The cribellar silks are produced from the spigots of the sieve-like prate. and considered as a quite different sort of catching silk with dry-adhesive properties. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1-2 pairs of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and two kinds of the aciniform spigots feed silk into the middle (A type) and the posterior spinnerets (both of A & B types), respectively.

인삼의 잎에서 유기된 Callus의 미세구조 (The Fine Structure of Callus Derived from Panax ginseng Leaves)

  • 박홍덕
    • Journal of Plant Biology
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    • 제19권4호
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    • pp.100-106
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    • 1976
  • The fine structure of the callus induced from epidermis of Panax ginseng leaves cultured on Murashige & Skoog medium plus kinetin 0.1mg/l, NAA 0.2mg/l and 2.4-D 0.5mg/l was observed. The cells composing callus tissue are mononucleus. Three types of cells were identified; cells with abundant cytoplasm, cells with relatively differentiated vacuoles and with numerous starch grains in the plastids and ones with highly differentiated vacuoles and with unsaturated lipid granules. Prolamellar body, plastid lamellae, plastid globules, stromacenter, fine tubules, crystal-containing body and DNA-like structures were observed in the stroma of the plastids. The chromoplasts were identified in some cells believed as the mother cells of secretory cells in secretory ducts. Curved or straight micro-fibrils of 100~150A in diameter were observed in the cytoplasm. And the characteristics of cell organelles and cell inclusions and the vacuole formation in callus tissues were discussed.

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Vertically Aligned Carbon Film Synthesized from Magnetically Oriented Polyacetylene using Morphology Retaining Carbonization

  • Goh, Munju;Choi, Yong Mun
    • Carbon letters
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    • 제13권4호
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    • pp.226-229
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    • 2012
  • Polyacetylene (PA) films with vertically aligned fibril morphology were synthesized in homeotropic nematic liquid crystal (N-LC) solvent by using a magnetic field of 5 Tesla as an external perturbation. Scanning electron microscope (SEM) photographs indicated that the lengths of fibrils from the substrate were $5-35{\mu}m$, depending on polymerization time. Carbonization was carried out using iodine-doped PA film and a morphology-retaining carbonization method. From the SEM results, we confirmed that the vertical morphology of the PA remains unchanged even after carbonization at $800^{\circ}C$. The weight loss of the films due to carbonization at $800^{\circ}C$ is about 20% of the weight of the film before iodine doping. It is expected that vertically aligned carbon might be a precursor for preparing vertical graphite materials, which materials could be useful for electrochemical energy storage and cell electrodes.

서모트로픽 액정폴리머와 폴리아미드6으로 성형된 얇은 복합재료의 미세구조형태 (Microstructural Morphology of Molded Thin Composites of Thermotropic Liquid Crystalline Polymer and Polyamide 6)

  • 최낙삼;최기영;하성규
    • 대한기계학회논문집A
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    • 제24권7호
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    • pp.1703-1711
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    • 2000
  • Microstructural morphology of molded composites of thermotropic liquid crystalline polymer(LCP) and polyamide 6 (PA6) has been studied as a function of epoxy fraction. Injection-moulding of a thin composite plaque at a temperature below the melting point of the LCP fibrils by suing the extruded LCP/PA6 pellets produced multi-layered structures: 1) the surface skin layer with thickness of 65-120 ym exhibiting a transverse orientation, 2) the sub-skin layer with an orientation perpendicular to the surface skin, i.e. in the flow direction, 3) the core layer with arc-curved flow patterns. Similar microstructural orientations were observed in the respective layers for the composite plaques with different fractions of epoxy.

Chondroitin Sulfate가 Colagen 성숙과 노화에 미치는 영향 (Effect of Chondroitin Sulfate on Collagen Maturity and Agning)

  • 하배진;김미향
    • 한국식품위생안전성학회지
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    • 제14권1호
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    • pp.45-54
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    • 1999
  • The purpose of this study was to examine the increased bone loss caused by ovariectomy through monitoring the concentrations of the collagen and the pyridinoline crosslinks of collagen. The ovariectomized rats treated for 8 weeks, were divided at random into two or three groups of 10. Ovariectomies were carried out from the saline-treated group (Ovx), the estrogentreated group (Ovx+ES) and chondroitin sulfate-treated group (Ovx+CS). Sham operations were performed on the sham-operated group (Sham). Ovx+ES and Ovx+CS groups showed the remarkably increased collagen and pyridinoline amount in the bone and cartilage compared to Ovx group. And as the result of the measurement of SOD, Catalase and GPx which are antioxidant enzyme, SOD and Catalase activities in Ovx group were much higher than in Sham group. But they were significantly decreased in Ovx+CS group. Based on these results, it is supposed that estrogen and condroitin sulfate can enhance collagen synthesis and affect the pyridinoline formation in collagen fibrils through stimulating lysyl oxidase activity. And it is also thought that chondroitin sulfate can inhibit aging by reducing antioxidant enzyme.

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셀룰라아제 처리에 의한 텐셀직물의 가수분해 (Hydrolysis of Tencel Fabrics by Cellulase Treatment)

  • 손경희;신윤숙
    • 한국가정과학회지
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    • 제2권1호
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    • pp.142-148
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    • 1999
  • Tencel fabrics were treated with cellulase after mechanical prefibrillation treatment. SEM analysis was carried out to study morphological change of the treated fabric. The cellulase-treated Tencel fabrics were evaluated for weight loss and tensile strength. X-ray diffraction method, moisture regain, and K/S value were used to elucidate crystalline structural changes occurred by cellulase treatment. Degree of polymerization and copper number of the cellulase-treated fabrics were also measured to estimate effect of hydrolysis. SEM analysis indicated that with treatment of prefibrillation and cellulase, fibrils were produced and damage occurred deep into the fiber. Increases in concentration and time of cellulase treatment increased weight loss and decreased tensile strength retention of the treated fabrics. As cellulase hydrolysis progressed, degree of crystallinity, moisture regain and K/S value were not much changed. (Korean J Human Ecology 2(1) : 142∼148, 1999)

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Analysis of Dissociation Pathway of HET-s Prion Using Steered Pulling Simulation

  • Kim, Minwoo;Cho, Tony;Shin, Seokmin
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.32-38
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    • 2017
  • Prion is a group of the proteins known for its infection mechanisms of Creutzfeldt-Jakob disease (CJD) and other diseases. Solved structures and proven biological roles of fungal prions add tremendous potential to conducting computational simulations. Our research focuses on the binding dynamics of HET-s(218-289), one of the heterokaryon fungal prion originated from Podospora anserina, by calculating the binding free energy using umbrella sampling at 300 K. The binding free energy calculated was $-54.5kcal\;mol^{-1}$, relatively similar to the binding energy of other amyloid fibrils. The simulation result suggests the thermodynamic properties of ${\beta}$-solenoid of HET-s prion and its similarity in dissociation pathways compared to amyloids.

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Pblyaniline의 전해중합특성 및 전기화학적 특성 (Characteristics of Electropolymerization and Electrochemical Properties of Polyaniline)

  • Moon, Seong-In;Yun, Mun-Soo
    • 대한전기학회논문지
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    • 제40권9호
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    • pp.883-892
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    • 1991
  • This paper presnets the characteristics of electropolymerization and electrochemicla propoerties of polyaniline(PAn). From the morphology study on the PAn surface, it seems that coagulation of the fibrils on the surface proceeds as the PAn grows, resulting in fibril clusters with new branches and more extensive voids. While PAn/Li cell is cycled at potential range between 2.9V and 3.7V in which the first strong reduction peak of 2.75V does not appear, its oxidation reduction capacities were increased up to about tenth cycle. Electricity efficiency of stable charge-discharge to deep discharge in PAn/Li cell was 42.9%. Average charge potential, avergae discharge potential, energy density, and charge-discharge energy efficiency of the PAn/Li cell were 3.4V, 3.25V, 132.9Wh/kg, and 95.6%, respectively.