1,721,095 research outputs found
Gut geschüttelt, nicht gerührt
No full textIn unserem Körper bewegen sich rote Blutzellen
durch feinste Adern, deren Durchmesser wesentlich
kleiner sind als die Zellen. Dazu müssen die Zellen
ihre Form aktiv anpassen, was ihnen eine sehr weiche,
elastische Zellmembran erlaubt. Diese unterliegt
kontinuierlichen Fluktuationen, die sowohl durch rein
thermische als auch aktiv metabolische Anregung
entstehen. Wenn es gelingt, beide Anteile experimentell
zu trennen und die aktive Bewegung im Detail zu
verstehen, lässt sich damit vielleicht die Physik aktiver
biologischer Motoren verstehen und so der Weg zu
mikroskopisch kleinen Antrieben ebnen
Direct Measurement of the Cortical Tension during the Growth of Membrane Blebs
No full textAbstractMechanics is at the heart of many cellular processes and its importance has received considerable attention during the last two decades. In particular, the tension of cell membranes, and more specifically of the cell cortex, is a key parameter that determines the mechanical behavior of the cell periphery. However, the measurement of tension remains challenging due to its dynamic nature. Here we show that a noninvasive interferometric technique can reveal time-resolved effective tension measurements by a high-accuracy determination of edge fluctuations in expanding cell blebs of filamin-deficient melanoma cells. The introduced technique shows that the bleb tension is ∼10–100 pN/μm and increases during bleb growth. Our results directly confirm that the subsequent stop of bleb growth is induced by an increase of measured tension, possibly mediated by the repolymerized actin cytoskeleton
Designing a LEGO-based microscope for an educational setting
No full textHere we present the design of a high-resolution, high-magnification micro- scope using LEGO® bricks and easily-available lenses. With the provided workflow and suggested experiments, we show that 9-to-13-year old students significantly increased their understanding of microscopy
Reversible Photoresponsive Modulation of Osmotic Pressure via Macromolecular Host–Guest Interaction
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