1,721,314 research outputs found
Nanomechanics of vimentin intermediate filament networks
No full textIntermediate filaments are one of three classes of fibrous proteins in the cytoskeleton of eukaryotes, the others being actin filaments and microtubules. The dense filamentous networks and bundles provide important mechanical stability for the cell. Here we directly measure both the structure and mechanical properties of an in vitro model system for intermediate filaments reconstituted from purified vimentin protein at 1 mg mL(-1). We show that the mesh size is on the order of 1 mm, a value that is preserved upon addition of divalent ions. These ions act as effective cross-linkers, further stiffening the network
Improving stability in lipid vesicle formation from microfluidic double emulsions by controlling solvent evaporation rate
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Influence of Internal Capsid Pressure on Viral Infection by Phage λ
No full textAbstractEjection of the genome from the virus, phage λ, is the initial step in the infection of its host bacterium. In vitro, the ejection depends sensitively on internal pressure within the virus capsid; however, the in vivo effect of internal pressure on infection of bacteria is unknown. Here, we use microfluidics to monitor individual cells and determine the temporal distribution of lysis due to infection as the capsid pressure is varied. The lysis probability decreases markedly with decreased capsid pressure. Of interest, the average lysis times remain the same but the distribution is broadened as the pressure is lowered
A picoliter array in a microfluidic device
No full textWe present a simple microfluidic device that uses an array of well-defined chambers to immobilize thousands of femtoliter-to picoliter-scale aqueous drops suspended in inert carrier oil. This device enables timelapse studies of large numbers of individual drops, while simultaneously enabling subsequent drop recovery
Intermediate filament mechanics in vitro and in the cell: from coiled coils to filaments, fibers and networks
No full textIntermediate filament proteins form filaments, fibers and networks both in the cytoplasm and the nucleus of metazoan cells. Their general structural building plan accommodates highly varying amino acid sequences to yield extended dimeric alpha-helical coiled coils of highly conserved design. These 'rod' particles are the basic building blocks of intrinsically flexible, filamentous structures that are able to resist high mechanical stresses, that is, bending and stretching to a considerable degree, both in vitro and in the cell. Biophysical and computer modeling studies are beginning to unfold detailed structural and mechanical insights into these major supramolecular assemblies of cell architecture, not only in the 'test tube' but also in the cellular and tissue context
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