resources:p2:start
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resources:p2:start [2014/01/13 17:15] – mourada | resources:p2:start [2014/01/15 18:48] – egz | ||
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====== BBB ====== | ====== BBB ====== | ||
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I. Introduction | I. Introduction | ||
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**5. Magnetohydrodynamic effect** | **5. Magnetohydrodynamic effect** | ||
+ | MICRO MAGNETOHYDRODYNAMICS | ||
- | ====== Epilepsy ====== | + | |
+ | Key words: water molecule, cyclic water molecule, superparamagnetic nanoparticles (SPMNPs), | ||
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+ | Application: | ||
+ | 1. Explaining why a static external magnetic field (from permanent magnet) will help SPMNs cross the Blood Brain Barrier (others use ultrasound to disrupt BBB, very dangerous) | ||
+ | 2. No one has explained the internalization of SPMNPs by biological cells. In our case, SPMNPs should be internalized by cells because epileptic magnetic fields are produced by intracellular component of the electric field. The extra-cellular is of no use for trapping the SPMNs. | ||
+ | Hypothesis | ||
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+ | Water molecules bond to each other and form cyclic water under the effect of weak and time varying magnetic (or strong but not both) fields. Cyclic water exhibits super-fluidity, | ||
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+ | Experimental setting | ||
+ | In microfluidic chanels where SPMNPs are positioned permannatly, | ||
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+ | Figure 1. (a) Effect of supperfluidity of water around spherical sperparamagnetic NPs.(b) fluid properties in absence of magnetic effects | ||
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+ | **Nanopore** | ||
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+ | Set-up ( which nanoseconds membrane? size of hole? monitoring? , ? (background: | ||
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+ | ====== Epilepsy ====== | ||
MRI imaging of superparamagnetic particles and rods aggregates in the brain | MRI imaging of superparamagnetic particles and rods aggregates in the brain | ||
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• Evidence of an off-resonance effect of SPMNPs on proton resonance | • Evidence of an off-resonance effect of SPMNPs on proton resonance | ||
• translation of diffusion coefficients into surgical coordinates. | • translation of diffusion coefficients into surgical coordinates. | ||
- | • Correlation with histopathological findings and intended epilepsy triggering zones | + | • Correlation with histopathological findings and intended epilepsy triggering zones |
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+ | ** Micro-coil and usu=sage of MRI + Injection of nano-particles in rat/mouse** | ||
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+ | ======III. | ||
+ | Simulation of superparamagnetic nanomaterial interacting with epileptic seizure-like driven uT magnetic fields | ||
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+ | I. Introduction | ||
+ | It is much more efficient to model the system before starting any in-vivo or in-vitro protocol. This will reduce the cost and help develop an efficient design tool, either for the imaging protols (size and morphology of the aggregates) or for the superparamagnetic materials to be used. Computer Simulation provides a means to virtually test the the interaction of the sad SPMNMs with neuronal bundles of different degrees of anisotropy (Fig. 1). It is Obvious that the isotropic configuration results in an overall magnetic | ||
+ | field that is null, hence the impossibility of measuring it at a distance, like its the case in MEG. As a mater of fact, MEG detects magnetic fiels developed by highly anisotropic configurations inherent to temporal and hypocampal regions of the brain. The aggregation of superparamagnetic | ||
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+ | {{: | ||
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+ | Figure 1. Tow different magnetic fields configurations | ||
+ | II. Time independent analysis | ||
+ | we will start with a modeling approach based on finite element modeling FEM to model SPMNMs absence of motion in presence of hydrodynamic forces and naturally occurring magnetic fields like the ones found in an epileptic seizure focus. An epileptic focus can be likened to a trap for the nanoparticles that eventually one has to asses its trapping efficiency. To do so, the neuronal network configurations will be considered independently from the particles and their motion. Using a static simulation that takes into account, magnetophoretic and hydrodinamic forces in their analytical forms, one can easily identify the spacial coordinates of regions where the forces add up to zero [1]. this simulaion work could be carried out on simulation platforms combining Matlab or ANSYS. | ||
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+ | III. Time dependent analysis | ||
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+ | Conventional simulation tools like ANSYS and COMSOL are not adapted to our application since they excel in modeling cases where applied fields are strong and thus, they consider their propagation unaffected by particles shapes and varying magnetic moments. In case of weak magnetic applied fields, the propagation of the magnetic field will be sparse and transient non uniform field are created within the particle itself, let alone at inter-sources distances. Consequently, | ||
+ | IV. Theoretical considerations | ||
+ | The paramagnetic particle (aspect ratio L/D) subjected to a magnetic field has a magnetic moment | ||
+ | where is the magnetic volume of the particle. Projecting | ||
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+ | If we replace the anisotropy of susceptibility of the rod by and if the magnetic field rotates (abruptly or at a pulsation | ||
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+ | and a viscous torque | ||
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+ | Where is the coefficient of hydrodynamic drag experienced by the rod and the instantaneous angular velocity of the rod, n, the viscosity of the fluid carrier, L the length and D the diameter of the nanoparticle respectively. | ||
+ | References | ||
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+ | [2] A. Anguelouch, R. L. Leheny, and D. H. Reich, " | ||
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+ | **Sandwich** | ||
+ | Literature? math? figures..... set-up? | ||
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This paper presents the design, optimization and optical characterization of an array electrostatic actuators based MEMS to be used as an adaptive optics component of a portable retinal imaging device. The proposed wave-front corrector is implemented in (CMC) polymump technology and features an array of cantilevers on which planar reflective gold thin films were deposited for characterization purposes. | This paper presents the design, optimization and optical characterization of an array electrostatic actuators based MEMS to be used as an adaptive optics component of a portable retinal imaging device. The proposed wave-front corrector is implemented in (CMC) polymump technology and features an array of cantilevers on which planar reflective gold thin films were deposited for characterization purposes. | ||
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+ | **Diagram and description of set-up** | ||
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Figure 1. Schematic of tumor detection unite | Figure 1. Schematic of tumor detection unite | ||
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+ | ====== Magneto-accoustic effect for breast surgery ====== | ||
+ | II. Breast surgery | ||
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+ | The therapeutic effect of focused ultrasound was known for quite a century now. Long ago, before MRI systems where made possible, there was absolutely no way to benefit from the therapeutic effect of focused | ||
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+ | 2.1 MRI free focused ultrasound surgery breast carcinoma | ||
+ | A totally acoustic imaging and ablation system as mentioned formerly is quiet impossible. Unless, one resorts to contrast agents to highlight tumors under an acoustic field, tumors will remain invisible for contemporary sonographs. Ultrasound contrast agents consist mainly of gas entrapping, polymeric micro capsules that reflect ultrasonic waves in a different way that differs from tissues. But gas bubbles are highly soluble in blood, conferring to the capsules, a very shot period of life within the body and making them unsuitable for ablation applications. The development of a new technique of visualization and ablation of tumors using acoustic field exclusively is eminent and calls for a new generation of tumor markers for ultrasound imaging and new technique of focusing acoustic energy in homogeneous media, in a way that is independent of human observation and correction. | ||
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+ | 2.2 All ultrasonic detection and ablation system | ||
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+ | Heterogeneity of propagation media has been studied by the navy in order to overcome the problem of object identification by sonars, in troubled waters. Phase conjugation, | ||
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+ | Figure. 2, All ultrasound detection and ablation of breast tumors | ||
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