General
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Direct Observation of Emulsion Morphology, Dynamics, and Demulsification
General ·Herein, we present the direct observation and quantification of a water-in-oil (w/o) emulsion, its destabilization, and the effect of additives on such processes at the nanoscale. This is achieved via liquid phase transmission electron microscopy (LPTEM), wherein a small volume of emulsion is encapsulated against vacuum in its liquid state to allow observation of its initial morphology and its evolution…
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Biomolecular densely grafted brush polymers - Oligonucleotides, oligosaccharides and oligopeptides
General ·Due to its ability to create complex cellular geometries with extremely fine resolution, mask projection microstereolithography (MPμSL) can be useful for fabricating designed tissue scaffolds and other biological constructs for use in Tissue Engineering and Regenerative Medicine. However, few photocurable materials with low cytotoxicity, adequate cell adhesion, and degradability can be processed with MPμSL. In this work, we present the…
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Chemical and physical transformations of carbon-based nanomaterials observed by liquid phase transmission electron microscopy
General ·This article addresses recent advances in liquid phase transmission electron microscopy (LPTEM) for studying nanoscale synthetic processes of carbon-based materials that are independent of the electron beam—those driven by nonradiolytic chemical or thermal reactions. In particular, we focus on chemical/physical formations and the assembly of nanostructures composed of organic monomers/polymers, peptides/DNA, and biominerals. The synthesis of carbon-based nanomaterials generally only…
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Complex nanoparticle diffusional motion in liquid-cell transmission electron microscopy
General ·Liquid-cell transmission electron microscopy (LCTEM) is a powerful in situ videography technique that has the potential to allow us to observe solution-phase dynamic processes at the nanoscale, including imaging the diffusion and interaction of nanoparticles. Artefactual effects imposed by the irradiated and confined liquid-cell vessel alter the system from normal “bulk-like” behavior in multiple ways. These artefactual LCTEM effects will…
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Enhanced elasticity in poly (acrylic acid) gels via synthesis in the presence of high concentrations of select salts
General ·Poly(acrylic acid) (PAA) gels synthesized via free-radical polymerization of acrylic acid, N,N′-methylenebisacrylamide and high molarities of salts in water exhibit properties markedly different from PAA gels synthesized without salt, even when the latter are incubated in high-molarity salt solutions after gelation. Particularly noteworthy is unusual mechanical behaviour that includes substantially increased elongation, increased modulus, and rapid recovery after strain. The…
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Design of a Fibrin Microthread-Based Composite Layer for Use in a Cardiac Patch
General ·The ability to modulate the mechanical properties, and cell alignment within a cardiac patch without hindering cell functionality may have significant impact on developing therapies for treating myocardial infarctions. We developed fibrin-based composite layers comprising aligned microthreads distributed uniformly throughout a hydrogel. Increasing the microthread volume fraction (∼5%, 11% and 22%) significantly increased the moduli of the scaffolds (20.6 ±…
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Microstereolithography of tissue scaffolds using a biodegradable photocurable polyester
General ·Due to its ability to create complex cellular geometries with extremely fine resolution, mask projection microstereolithography (MPμSL) can be useful for fabricating designed tissue scaffolds and other biological constructs for use in Tissue Engineering and Regenerative Medicine. However, few photocurable materials with low cytotoxicity, adequate cell adhesion, and degradability can be processed with MPμSL. In this work, we present the…