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When Cells Hit the Wall: UCLA Engineers Put The Squeeze on Cells to Diagnose Disease

By Guest PostMay 6, 2012Health, Scienceaids, amander clark, balloon, cancer, cells, chemical tags, chronic inflammation, cytopathologist, daniel gossett, deformability cytometer, diagnose disease, dino di carlo, dna arrangement, elastic properties, extract information, henry tse, honey, immune disorder, immune system, infection, jian yu rao, mesothelial cells, microfluidic chip, nuclei, rubber balloon, shape, software, steven chu, Technology, ucla engineers, viscous, white blood cells

If you throw a rubber balloon filled with water against a wall, it will spread out and deform on impact, while the same balloon filled with honey, which is more viscous, will deform much less. If the balloon’s elastic rubber was stiffer, an even smaller change in shape would be observed.

By simply analyzing how much a balloon changes shape upon hitting a wall, you can uncover information about its physical properties.

Although cells are not simple sacks of fluid, they also contain viscous and elastic properties related to the membranes that surround them; their internal structural elements, such as organelles; and the packed DNA arrangement in their nuclei. Because variations in these properties can provide information about cells’ state of activity and can be indicative of diseases such as cancer, they are important to measure. (more…)

Images Capture Split Personality of Dense Suspensions

By Guest PostApril 9, 2012Sciencedna microarray, drop forms, heinrich jaeger, jeffrey morris, marc miskin, mathematical model, nozzle diameter, particle, phenomena, steve koppes, university of chicago, viscosity, viscous, viscous liquids, viscous mixture, zirconium dioxide

Stir lots of small particles into water, and the resulting thick mixture appears highly viscous. When this dense suspension slips through a nozzle and forms a droplet, however, its behavior momentarily reveals a decidedly non-viscous side. University of Chicago physicists recorded this surprising behavior in laboratory experiments using high-speed photography, which can capture action taking place in one hundred-thousandths of a second or less.

UChicago graduate student Marc Miskin and Heinrich Jaeger, the William J. Friedman and Alicia Townsend Friedman Professor in Physics, expected that the dense suspensions in their experiments would behave strictly like viscous liquids, which tend to flow less freely than non-viscous liquids. Viscosity certainly does matter as the particle-laden liquid begins to exit the nozzle, but not at the moment where the drop’s thinning neck breaks in two. (more…)

UCLA Physicists Report Nanotechnology Feat With Proteins

By Guest PostDecember 24, 2011Scienceatp, class of enzymes, elastic, enzyme, giovanni zocchi, gk, guanylate kinase, human hair, kinases, liquid, liquids flow, mechanical energy, mechanical response, nanomechanical measurements, nanometer, Nanotechnology, phosphate group, protein molecules, resolution, solid, stress, university of Illinois, visco elastic, visco elastic transition, viscoelastic behavior, viscoelastic regime, viscous, yong wang

UCLA physicists have made nanomechanical measurements of unprecedented resolution on protein molecules.

The new measurements, by UCLA physics professor Giovanni Zocchi and former UCLA physics graduate student Yong Wang, are approximately 100 times higher in resolution than previous mechanical measurements, a nanotechnology feat which reveals an isolated protein molecule, surprisingly, is neither a solid nor a liquid.

“Proteins are the molecular machines of life, the molecules we are made of,” Zocchi said. “We have found that sometimes they behave as a solid and sometimes as a liquid. (more…)

Tag Archives: viscous

When Cells Hit the Wall: UCLA Engineers Put The Squeeze on Cells to Diagnose Disease

Images Capture Split Personality of Dense Suspensions

UCLA Physicists Report Nanotechnology Feat With Proteins