The Experts below are selected from a list of 4668600 Experts worldwide ranked by ideXlab platform

Julie A Theriot - One of the best experts on this subject based on the ideXlab platform.

  • a caulobacter mreb mutant with irregular cell shape exhibits compensatory widening to maintain a preferred surface area to volume Ratio
    Molecular Microbiology, 2014
    Co-Authors: Leigh K Harris, Natalie A Dye, Julie A Theriot
    Abstract:

    Summary Rod-shaped bacteria typically elongate at a uniform width. To investigate the genetic and physiological determinants involved in this process, we studied a mutation in the morphogenetic protein MreB in Caulobacter crescentus that gives rise to cells with a variable-width phenotype, where cells have regions that are both thinner and wider than wild-type. During growth, individual cells develop a balance of wide and thin regions, and mutant MreB dynamically localizes to poles and thin regions. Surprisingly, the surface area to volume Ratio of these irregularly shaped cells is, on average, very similar to wild-type. We propose that, while mutant MreB localizes to thin regions and promotes rod-like growth there, wide regions develop as a compensatory mechanism, allowing cells to maintain a wild-type-like surface area to volume Ratio. To support this model, we have shown that cell widening is abrogated in growth conditions that promote higher surface area to volume Ratios, and we have observed individual cells with high Ratios return to wild-type levels over several hours by developing wide regions, suggesting that compensation can take place at the level of individual cells.

G Guisbiers - One of the best experts on this subject based on the ideXlab platform.

  • Size-dependent materials properties towards a universal equation
    2013
    Co-Authors: G Guisbiers
    Abstract:

    Abstract Due to the lack of experimental values concerning some material properties at the nanoscale, it is interesting to evaluate this theoretically. Through a ‘‘top– down’ ’ approach, a universal equation is developed here which is particularly helpful when experiments are difficult to lead on a specific material property. It only requires the knowledge of the surface area to volume Ratio of the nanomaterial, its size as well as the statistic (Fermi–Dirac or Bose–Einstein) followed by the particles involved in the considered material property. Comparison between different existing theoretical models and the proposed equation is done

  • Size-Dependent Materials Properties Toward a Universal Equation
    Nanoscale Research Letters, 2010
    Co-Authors: G Guisbiers
    Abstract:

    Due to the lack of experimental values concerning some material properties at the nanoscale, it is interesting to evaluate this theoretically. Through a “top–down” approach, a universal equation is developed here which is particularly helpful when experiments are difficult to lead on a specific material property. It only requires the knowledge of the surface area to volume Ratio of the nanomaterial, its size as well as the statistic (Fermi–Dirac or Bose–Einstein) followed by the particles involved in the considered material property. Comparison between different existing theoretical models and the proposed equation is done.

Omer Nur - One of the best experts on this subject based on the ideXlab platform.

  • Zinc oxide nanowires for biomedical sensing and analysis
    Nanomedicine, 2012
    Co-Authors: Magnus Willander, Omer Nur
    Abstract:

    : Nanowires (NWs), with their high surface area to volume Ratio, constitute excellent natural signal transduction elements. The demanding need for a fast real-time selective sensor detection of ions and biological analytes has led to rapid progress in the use of nanostructures in general as elements for developing such sensors. Moreover, zinc oxide (ZnO) NWs, which are bio-safe and biocompatible materials, have been used to develop potentiometric electrochemical sensors suitable for intracellular and extracellular small volumes for selective and sensitive analysis of metallic ions and other biological analytes. The developed potentiometric sensors presented in this chapter have shown a linear response in a wide range of applications and provide a promising approach for developing sensors for physiological environments.

Philippe Connes - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Surface-Area-to-Volume Ratio, internal viscosity and membrane viscoelasticity on red blood cell deformability measured in isotonic condition
    Scientific Reports, 2019
    Co-Authors: Céline Renoux, Magalie Faivre, Amel Bessaa, Lydie Da Costa, Philippe Joly, Alexandra Gauthier, Philippe Connes
    Abstract:

    osmotic gradient ektacytometry is the gold standard to assess red blood cell (RBC) deformability. It has been proposed that, when measured in isotonic condition, RBC deformability at low shear stress would depend on membrane elasticity while it would be influenced by internal viscosity when measured at high shear stress, but this hypothesis needs to be further addressed. Healthy RBCs were rigidified by treatment with lysolecithine (LpC), diamide or nystatine associated with hyperosmolar solutions (osMo), which reduces membrane surface area, decreases membrane elasticity or promotes cell dehydRation, respectively. Diamide treatment resulted in a decrease in isotonic RBC deformability at all shear stresses tested (i.e. from 0.3 to 30 Pa). LPC and OSMO treatments caused a decrease in isotonic RBC deformability above 3 Pa only. Isotonic RBC deformability from patients with hereditary spherocytosis or sickle cell disease was mainly decreased above 1.69 Pa. Our findings indicate that decreased isotonic RBC deformability at shear stresses above 3 Pa would be related to a reduction in the Surface-Area-to-Volume Ratio and/or to a loss of membrane elasticity and/or to an increase in internal viscosity while a decrease of RBC deformability below 3 Pa would reflect a loss of membrane elasticity.

Leigh K Harris - One of the best experts on this subject based on the ideXlab platform.

  • a caulobacter mreb mutant with irregular cell shape exhibits compensatory widening to maintain a preferred surface area to volume Ratio
    Molecular Microbiology, 2014
    Co-Authors: Leigh K Harris, Natalie A Dye, Julie A Theriot
    Abstract:

    Summary Rod-shaped bacteria typically elongate at a uniform width. To investigate the genetic and physiological determinants involved in this process, we studied a mutation in the morphogenetic protein MreB in Caulobacter crescentus that gives rise to cells with a variable-width phenotype, where cells have regions that are both thinner and wider than wild-type. During growth, individual cells develop a balance of wide and thin regions, and mutant MreB dynamically localizes to poles and thin regions. Surprisingly, the surface area to volume Ratio of these irregularly shaped cells is, on average, very similar to wild-type. We propose that, while mutant MreB localizes to thin regions and promotes rod-like growth there, wide regions develop as a compensatory mechanism, allowing cells to maintain a wild-type-like surface area to volume Ratio. To support this model, we have shown that cell widening is abrogated in growth conditions that promote higher surface area to volume Ratios, and we have observed individual cells with high Ratios return to wild-type levels over several hours by developing wide regions, suggesting that compensation can take place at the level of individual cells.