Mechanistic Observation of Interactions between Macrophages and Inorganic Particles with Different Densities

Many different types of inorganic materials are processed into nano/microparticles for medical utilization. The impact of selected key characteristics of these particles, including size, shape, and surface chemistries, on biological systems, is frequently studied in clinical contexts. However, one of the most important basic characteristics of these particles, their density, is yet to be investigated. When the particles are designed for drug delivery, highly mobile macrophages are the major participants in cellular levels that process them in vivo. As such, it is essential to understand the impact of particles’ densities on the mobility of macrophages. Here, inorganic particles with different densities are applied, and their interactions with macrophages studied. A set of these particles are incubated with the macrophages and the outcomes are explored by optical microscopy. This microscopic view provides the understanding of the mechanistic interactions between particles of different densities and macrophages to conclude that the particles’ density can affect the migratory behaviors of macrophages: the higher the density of particles engulfed inside the macrophages, the less mobile the macrophages become. This work is a strong reminder that the density of particles cannot be neglected when they are designed to be utilized in biological applications

Simulation study of Solar Wind interaction with Mercury's magnetosphere

International audienceThe interaction of the Hermean magnetosphere and the Solar Wind is investigated using a 3-dimensional parallel multi-species hybrid model. In the simulation, it is assumed that Mercury is at its Aphelion and the IMF orientation is the orientation reported by MESSENGER during its first flyby. The principal regions of this interaction are reproduced by the hybrid model and the electromagnetic field spatial variations are described as well. This model represents a strong tool to study Mercury's plasma environment

Hybrid simulation of the interactions between Ganymede's magnetosphere and the jovian plasma

International audienceGanymede is the only magnetized moon in the solar system embedded in its large parent's planet magnetosphere. Its internal magnetic field interacts strongly with the Jovian magnetospheric plasma and makes unique this interaction. Thermal magnetospheric ions co-rotate at about 180km/s and are mainly composed of oxygen ions and protons. Few MHD models succeeded in describing accurately the global shape of the magnetosphere and reproduce most of the signatures observed by Galileo but they are unable to take in consideration high gyroradius effects or multiple ions dynamic. Therefore we developed a 3D parallel multi-species hybrid model based on a CAM-CL algorithm which has been largely used for other magnetized or unmagnetized body such as Mars, Titan or Mercury

Simulated Interaction of Ganymede's Magnetosphere with the Jovian Plasma

International audienceGanymede is the only magnetized moon in the solar system embedded in its large parent's planet magnetosphere. Its internal magnetic field interacts strongly with the Jovian magnetospheric plasma and makes unique this interaction. Thermal magnetospheric ions co-rotate at about 180km/s and are mainly composed of oxygen ions and protons. Few MHD models [1],[2] succeeded in describing accurately the global shape of the magnetosphere and reproduce most of the signatures observed by Galileo but they are unable to take in consideration high gyroradius effects or multiple ions dynamic. Therefore we developed a 3D parallel multi-species hybrid model based on a CAM-CL algorithm [3] which has been largely used for other magnetized or unmagnetized body such as Mars, Titan or Mercury

Simulated Interaction of Ganymede's Magnetosphere with the Jovian Plasma

International audienceGanymede is the only magnetized moon in the solar system embedded in its large parent's planet magnetosphere. Its internal magnetic field interacts strongly with the Jovian magnetospheric plasma and makes unique this interaction. Thermal magnetospheric ions co-rotate at about 180km/s and are mainly composed of oxygen ions and protons. Few MHD models [1],[2] succeeded in describing accurately the global shape of the magnetosphere and reproduce most of the signatures observed by Galileo but they are unable to take in consideration high gyroradius effects or multiple ions dynamic. Therefore we developed a 3D parallel multi-species hybrid model based on a CAM-CL algorithm [3] which has been largely used for other magnetized or unmagnetized body such as Mars, Titan or Mercury

A new 3D parallel multi-species hybrid model for Solar Wind - Mars interaction

International audienceIn the frame of the HELIOSARES project (PI F. Leblanc) dedicated to the modeling of Mars environment (neutral and charged species) from the lower atmosphere to the solar wind, a modeling effort of parallelization has been conducted. Such model allows having a kinetic description of the ions with a rather improved spatial resolution (smaller than the ion inertial less). The latest progresses are reported and simulations results with a uniform spatial resolution of 75 km are presented

Qualitative spectroscopic characterization of the matrix-silane coupling agent interface across metal fibre reinforced ion exchange resin composite membranes

The characterization of novel metal reinforced electro-dialysis ion exchange membranes, for water desalination, by attenuated total reflectance Fourier transform infrared spectroscopy mapping is presented in this paper. The surface of the porous stainless steel fibre meshes was treated in order to enhance the amount of surface oxide groups and increase the material hydrophilicity. Then, the metal membranes were functionalized through a sol-gel reaction with silane coupling agents to enhance the affinity with the ion exchange resins and avoid premature metal oxidation due to redox reactions at the metal-polymer interface. Polished cross sections of the composite membranes embedded into an epoxy resin revealed interfaces between metallic frameworks and the silane layer at the interface with the ion exchange material. The morphology of the metal-polymer interface was investigated with scanning electron microscopy and Fourier transform infrared micro-spectroscopy. Fourier transform infrared mapping of the interfaces was performed using the attenuated total reflectance mode on the polished cross-sections at the Australian Synchrotron. The nature of the interface between the metal framework and the ion exchange resin was shown to be homogeneous and the coating thickness was found to be around 1 μm determined by Fourier transform infrared micro-spectroscopy mapping. The impact of the coating on the properties of the membranes and their potential for water desalination by electro-dialysis are also discussed

Toward mid-infrared nonlinear optics applications of silicon carbide microdisks engineered by lateral under-etching [invited]

We report the fabrication and characterization of silicon carbide microdisks on top of silicon pillars suited for applications from near-to mid-infrared. We probe 10 ?m diameter disks with different under-etching depths, from 4 ?m down to 1.4 ?m, fabricated by isotropic plasma etching and extract quality factors up to 8400 at telecom wavelength. Our geometry is suited to present high Q single-mode operation. We experimentally demonstrate high-order whispering-gallery mode suppression while preserving the fundamental gallery mode and investigate some requirements for nonlinear optics applications on this platform, specifically in terms of quality factor and dispersion for Kerr frequency comb generation

Mid-infrared nonlinear optical response of Si-Ge waveguides with ultra-short optical pulses

We characterize the nonlinear optical response of low loss Si0.6Ge0.4 / Si waveguides in the mid-infrared between 3.3 μm and 4 μm using femtosecond optical pulses. We estimate the three and four-photon absorption coefficients as well as the Kerr nonlinear refractive index from the experimental measurements. The effect of multiphoton absorption on the optical nonlinear Kerr response is evaluated and the nonlinear figure of merit estimated providing some guidelines for designing nonlinear optical devices in the mid-IR. Finally, we compare the impact of free-carrier absorption at mid-infrared wavelengths versus near-infrared wavelengths for these ultra-short pulses