14 research outputs found
Stress-corrosion mechanisms in silicate glasses
The present review is intended to revisit the advances and debates in the
comprehension of the mechanisms of subcritical crack propagation in silicate
glasses almost a century after its initial developments. Glass has inspired the
initial insights of Griffith into the origin of brittleness and the ensuing
development of modern fracture mechanics. Yet, through the decades the real
nature of the fundamental mechanisms of crack propagation in glass has escaped
a clear comprehension which could gather general agreement on subtle problems
such as the role of plasticity, the role of the glass composition, the
environmental condition at the crack tip and its relation to the complex
mechanisms of corrosion and leaching. The different processes are analysed here
with a special focus on their relevant space and time scales in order to
question their domain of action and their contribution in both the kinetic laws
and the energetic aspects.Comment: Invited review article - 34 pages Accepted for publication in J.
Phys. D: Appl. Phy
Epigenetic remodelling licences adult cholangiocytes for organoid formation and liver regeneration.
Following severe or chronic liver injury, adult ductal cells (cholangiocytes) contribute to regeneration by restoring both hepatocytes and cholangiocytes. We recently showed that ductal cells clonally expand as self-renewing liver organoids that retain their differentiation capacity into both hepatocytes and ductal cells. However, the molecular mechanisms by which adult ductal-committed cells acquire cellular plasticity, initiate organoids and regenerate the damaged tissue remain largely unknown. Here, we describe that ductal cells undergo a transient, genome-wide, remodelling of their transcriptome and epigenome during organoid initiation and in vivo following tissue damage. TET1-mediated hydroxymethylation licences differentiated ductal cells to initiate organoids and activate the regenerative programme through the transcriptional regulation of stem-cell genes and regenerative pathways including the YAP-Hippo signalling. Our results argue in favour of the remodelling of genomic methylome/hydroxymethylome landscapes as a general mechanism by which differentiated cells exit a committed state in response to tissue damage.RCUK
Cancer Research UK
ERC
H2020
Wellcome Trus
The Intersection of Interfacial Forces and Electrochemical Reactions
We review recent developments in experimental techniques that simultaneously combine measurements of the interaction forces or energies between two extended surfaces immersed in electrolyte solutionsâprimarily aqueousâwith simultaneous monitoring of their (electro)chemical reactions and controlling the electrochemical surface potential of at least one of the surfaces. Combination of these complementary techniques allows for simultaneous real time monitoring of angstrom level changes in surface thickness and roughness, surfaceâsurface interaction energies, and charge and mass transferred via electrochemical reactions, dissolution, and adsorption, and/or charging of electric double layers. These techniques employ the surface forces apparatus (SFA) combined with various âelectrochemical attachmentsâ for in situ measurements of various physical and (electro)chemical properties (e.g., cyclic voltammetry), optical imaging, and electric potentials and currents generated naturally during an interaction, as well as when electric fields (potential differences) are applied between the surfaces and/or solutionâin some cases allowing for the chemical reaction equation to be unambiguously determined. We discuss how the physical interactions between two different surfaces when brought close to each other (<10 nm) can affect their chemistry, and suggest further extensions of these techniques to biological systems and simultaneous in situ spectroscopic measurements for chemical analysis