Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 59 (1988), S. 1399-1404 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new rheometer has been designed to measure the rheological properties at low Reynolds number of microliter quantities of opaque suspensions. The rheometer uses a falling-ball technique to measure steady-state viscosity and a vertically oscillating, magnetically driven ball for viscoelastic measurements. The motion of the ball is tracked by ultrasound echo location, in which sound waves are transmitted and received by an ultrasound transducer mounted at the base of the tube. Concentrated suspensions of red blood cells are used as opaque test samples. The results obtained are in good agreement with those reported in the literature. The data confirm the fact that a concentrated suspension of red blood cells behaves as a shear thinning material and that the energy stored by the suspension during an oscillatory cycle increases with frequency. Testing of the rheometer is also made by using a Newtonian silicone oil. Viscosity measurements obtained with both the falling- and oscillating-ball methods are consistent and are within 2% of the value of 47.3±0.5 cP given by the Cannon-Fenske viscometer. However, it is found that the oscillating-ball technique gives the largest standard deviation, 6%, as opposed to 2% for the falling-ball technique.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 855 (1986), S. 105-114 
    ISSN: 0005-2736
    Keywords: Elastic modulus ; Erythrocyte membrane ; Ghost preparation ; Membrane viscosity ; Osmolality ; Rheology ; Viscoelasticity
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 838-852 
    ISSN: 0006-3592
    Keywords: hybridoma cells ; cell cycle ; morphology ; geometry ; mechanical properties ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Morphological, geometrical, and rheological properties of the GAP A3 hybridoma cell line have been evaluated as a function of the cell cycle. Interference contrast video microscopy and scanning electron microscopy (SEM) showed that a sample of cells taken from the middle of the exponential growht phase displayed a range of cell morphologies, consistent with a heterogeneous growing culture. Micropipet manipulation was used to measure the geometrical (cell volume) and mechanical (cortical tension and apparent cell viscosity) properties of single cells selected at random from a sample in the middle of the exponential growth phase. Consistent with the range of morphologies, cell volumes (1400 to 5700 μm3) and apparent viscosities (430 to 1.2 × 104 P) showed a wide range of values at 37°C, demonstrating that a hybridoma cell line cannot be characterized by a single value for any one property, and that properties must be related to their cycle dependence when considering proliferating cells. Direct, video-microscopic observation of synchronized cells, and of individual cells that were followed throughout their cell cycle, allowed us to correlated distinct morphologies with phases of the cell cycle. As the cell cycle progresses, an increase in cell volume by a factor of 3 to 4is accompanied by an overall increase in apparent cell viscosity by approximately the same ratio, consistent with an accumulation of more cytoplasmic material in the older cells. Also, a decrease in average apparent viscosity by a factor of 10. These results are important in order to evaluate the possible role of certain structural, cell-cycle dependent features in shear and abrasion sensitivity. This is a problem of current concern in the bioreactor culture of mammalian cells.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...