Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transient Nanoscopic Phase Separation in Biological Lipid Membranes
  Resolved by Planar Plasmonic Antennas   Nanoscale membrane assemblies of sphingolipids, cholesterol, and certain
proteins, also known as lipid rafts, play a crucial role in facilitating a
broad range of important cell functions. Whereas on living cell membranes lipid
rafts have been postulated to have nanoscopic dimensions and to be highly
transient, the existence of a similar type of dynamic nanodomains in
multicomponent lipid bilayers has been questioned. Here, we perform
fluorescence correlation spectroscopy on planar plasmonic antenna arrays with
different nanogap sizes to assess the dynamic nanoscale organization of mimetic
biological membranes. Our approach takes advantage of the highly enhanced and
confined excitation light provided by the nanoantennas together with their
outstanding planarity to investigate membrane regions as small as 10 nm in size
with microsecond time resolution. Our diffusion data are consistent with the
coexistence of transient nanoscopic domains in both the liquid-ordered and the
liquid-disordered microscopic phases of multicomponent lipid bilayers. These
nanodomains have characteristic residence times between 30 and 150 {\mu}s and
sizes around 10 nm, as inferred from the diffusion data. Thus, although
microscale phase separation occurs on mimetic membranes, nanoscopic domains
also coexist, suggesting that these transient assemblies might be similar to
those occurring in living cells, which in the absence of raft-stabilizing
proteins are poised to be short-lived. Importantly, our work underscores the
high potential of photonic nanoantennas to interrogate the nanoscale
heterogeneity of native biological membranes with ultrahigh spatiotemporal
resolution.

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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat