Monte Carlo simulations of synchrotron X-ray dose affecting root growth during in vivo tomographic imaging.

Synchrotron X-ray computed tomography (XCT) has been increasingly applied to study the in vivo dynamics of root growth and rhizosphere processes. However, minimizing radiation-induced damage to root growth warrants further investigation. Our objective was to develop a robust approach for modeling and evaluating ways to reduce synchrotron X-ray dose effects on root growth during in vivo imaging.

A pore-scale investigation of the effect of nanoparticle injection on properties of sandy porous media.

Nanoremediation is a new groundwater remediation technology in which nanoparticles (NPs) are injected into the sub-surface to promote in-situ degradation of aquifer contaminants. Although nanoremediation is an effective process to eliminate contaminants in-situ, its success relies on sufficiently mobile NPs that can reach the contaminated zones and remain there to facilitate chemical degradation of contaminants. Therefore, understanding the main parameters that control the mobility and retention of NPs in saturated porous media is a key component of designing a successful nanoremediation process.

Trabecular architecture during the healing process of a tibial diaphysis defect.

The adaptation of trabecular bone microstructure to mechanical loads has been intensively investigated. However, loading-unrelated aspects of trabecular architecture remain unclear. We used synchrotron radiation-based X-ray microtomography to study the 3D microarchitecture of newly formed trabecular tissue in a defect produced in the cortical region of the rat tibia diaphysis, in the absence (7, 14, and 21 days) or the presence (21 days) of carbonated hydroxyapatite/alginate (cHA) microspheres.

Pore-scale investigation of the use of reactive nanoparticles for in situ remediation of contaminated groundwater source.

Nanoscale zero-valent iron (nZVI) particles have excellent capacity for in situ remediation of groundwater resources contaminated by a range of organic and inorganic contaminants. Chlorinated solvents are by far the most treated compounds. Studies at column, pilot, and field scales have reported successful decrease in contaminant concentration upon injection of nZVI suspensions in the contaminated zones.

An X-ray computed micro-tomography dataset for oil removal from carbonate porous media.

This study reveals the pore-scale details of oil mobilisation and recovery from a carbonate rock upon injection of aqueous nanoparticle (NP) suspensions. X-ray computed micro-tomography (μCT), which is a non-destructive imaging technique, was used to acquire a dataset which includes: (i) 3D images of the sample collected at the end of fluid injection steps, and (ii) 2D radiogram series collected during fluid injections. The latter allows monitoring fluid flow dynamics at time resolutions down to a few seconds using a laboratory-based μCT scanner.

Location of water in fresh sugarcane bagasse observed by synchrotron X-ray microtomography.

Sugarcane bagasse is a vast lignocellulosic byproduct generated in the industry with ~50% humidity (1 kg dry matter associated with 1 kg water). Although the presence of water brings deleterious consequences for combustion, storage and sugar extraction, the location of water in fresh bagasse remains unknown. In this work, we use synchrotron X-ray microtomography for non-invasive 3D imaging of fresh bagasse particles, which allows the visualization of intraparticle water.

High-resolution synchrotron-based X-ray microtomography as a tool to unveil the three-dimensional neuronal architecture of the brain.

The assessment of neuronal number, spatial organization and connectivity is fundamental for a complete understanding of brain function. However, the evaluation of the three-dimensional (3D) brain cytoarchitecture at cellular resolution persists as a great challenge in the field of neuroscience. In this context, X-ray microtomography has shown to be a valuable non-destructive tool for imaging a broad range of samples, from dense materials to soft biological specimens, arisen as a new method for deciphering the cytoarchitecture and connectivity of the brain.

The Dynamics of Nanoparticle-enhanced Fluid Displacement in Porous Media - A Pore-scale Study.

This work provides new insights into the dynamics of silica nanoparticle-based removal of organic fluids (here oil) from naturally occurring porous media. We have used 4D (time-resolved 3D) imaging at pore-scale using X-ray computed micro-tomography (μCT) technique. The captured 3D tomographic time-series data reveal the dynamics of immiscible oil displacement from a carbonate rock upon injection of nanoparticle (NP) suspensions (0.

Observing the solubilization of lipid bilayers by detergents with optical microscopy of GUVs.

The solubilization of lipid bilayers by detergents was studied with optical microscopy of giant unilamellar vesicles (GUVs) composed of palmitoyl oleoyl phosphatidylcholine (POPC). A solution of the detergents Triton X-100 (TX-100) and sodium dodecyl sulfate (SDS) was injected with a micropipette close to single GUVs. The solubilization process was observed with phase contrast and fluorescence microscopy and found to be dependent on the detergent nature.

Giant vesicles under oxidative stress induced by a membrane-anchored photosensitizer.

We have synthesized the amphiphile photosensitizer PE-porph consisting of a porphyrin bound to a lipid headgroup. We studied by optical microscopy the response to light irradiation of giant unilamellar vesicles of mixtures of unsaturated phosphatidylcholine lipids and PE-porph. In this configuration, singlet oxygen is produced at the bilayer surface by the anchored porphyrin.