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Bistability

The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform

Thomas Wilhelm – 1st expert on this subject based on the ideXlab platform

  • the smallest chemical reaction system with Bistability
    BMC Systems Biology, 2009
    Co-Authors: Thomas Wilhelm

    Abstract:

    Background
    Bistability underlies basic biological phenomena, such as cell division, differentiation, cancer onset, and apoptosis. So far biologists identified two necessary conditions for Bistability: positive feedback and ultrasensitivity.

  • The smallest chemical reaction system with Bistability
    BMC Systems Biology, 2009
    Co-Authors: Thomas Wilhelm

    Abstract:

    BACKGROUND: Bistability underlies basic biological phenomena, such as cell division, differentiation, cancer onset, and apoptosis. So far biologists identified two necessary conditions for Bistability: positive feedback and ultrasensitivity.\n\nRESULTS: Biological systems are based upon elementary mono- and bimolecular chemical reactions. In order to definitely clarify all necessary conditions for Bistability we here present the corresponding minimal system. According to our definition, it contains the minimal number of (i) reactants, (ii) reactions, and (iii) terms in the corresponding ordinary differential equations (decreasing importance from i-iii). The minimal bistable system contains two reactants and four irreversible reactions (three bimolecular, one monomolecular).We discuss the roles of the reactions with respect to the necessary conditions for Bistability: two reactions comprise the positive feedback loop, a third reaction filters out small stimuli thus enabling a stable ‘off’ state, and the fourth reaction prevents explosions. We argue that prevention of explosion is a third general necessary condition for Bistability, which is so far lacking discussion in the literature.Moreover, in addition to proving that in two-component systems three steady states are necessary for Bistability (five for tristability, etc.), we also present a simple general method to design such systems: one just needs one production and three different degradation mechanisms (one production, five degradations for tristability, etc.). This helps modelling multistable systems and it is important for corresponding synthetic biology projects.\n\nCONCLUSION: The presented minimal bistable system finally clarifies the often discussed question for the necessary conditions for Bistability. The three necessary conditions are: positive feedback, a mechanism to filter out small stimuli and a mechanism to prevent explosions. This is important for modelling Bistability with simple systems and for synthetically designing new bistable systems. Our simple model system is also well suited for corresponding teaching purposes.

Marko Loncar – 2nd expert on this subject based on the ideXlab platform

  • Mitigation of optical Bistability in Si-based mid-infrared photonic crystal cavities using surface treatments
    2012 Conference on Lasers and Electro-Optics (CLEO), 2012
    Co-Authors: Raji Shankar, Irfan Bulu, Rick Leijssen, Kogos Leonard, Marko Loncar

    Abstract:

    We present evidence of thermally-induced optical Bistability in our mid-infrared photonic crystal cavities operating at 4.5 μm. Surface treatments are used to mitigate Bistability and improve device Q-factor, with the highest measured Q ~ 45,000 at 4.48 μm.

  • study of thermally induced optical Bistability and the role of surface treatments in si based mid infrared photonic crystal cavities
    Optics Express, 2011
    Co-Authors: Raji Shankar, Irfan Bulu, Rick Leijssen, Marko Loncar

    Abstract:

    We report the observation of optical Bistability in Si-based photonic crystal cavities operating around 4.5 µm. Time domain measurements indicate that the source of this optical Bistability is thermal, with a time constant on the order of 5 µs. Quality (Q) factor improvement is shown by the use of surface treatments (wet processes and annealing), resulting in a significant increase in Q-factor, which in our best devices is on the order of ~45,000 at 4.48 µm. After annealing in a N2 environment, optical Bistability is no longer seen in our cavities.

Raji Shankar – 3rd expert on this subject based on the ideXlab platform

  • Mitigation of optical Bistability in Si-based mid-infrared photonic crystal cavities using surface treatments
    2012 Conference on Lasers and Electro-Optics (CLEO), 2012
    Co-Authors: Raji Shankar, Irfan Bulu, Rick Leijssen, Kogos Leonard, Marko Loncar

    Abstract:

    We present evidence of thermally-induced optical Bistability in our mid-infrared photonic crystal cavities operating at 4.5 μm. Surface treatments are used to mitigate Bistability and improve device Q-factor, with the highest measured Q ~ 45,000 at 4.48 μm.

  • study of thermally induced optical Bistability and the role of surface treatments in si based mid infrared photonic crystal cavities
    Optics Express, 2011
    Co-Authors: Raji Shankar, Irfan Bulu, Rick Leijssen, Marko Loncar

    Abstract:

    We report the observation of optical Bistability in Si-based photonic crystal cavities operating around 4.5 µm. Time domain measurements indicate that the source of this optical Bistability is thermal, with a time constant on the order of 5 µs. Quality (Q) factor improvement is shown by the use of surface treatments (wet processes and annealing), resulting in a significant increase in Q-factor, which in our best devices is on the order of ~45,000 at 4.48 µm. After annealing in a N2 environment, optical Bistability is no longer seen in our cavities.