Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrodynamic interactions in DNA thermophoresis   We theoretically study the molecular-weight dependence of DNA thermophoresis,
which arises from mutual advection of the n repeat units of the molecular
chain. As a main result we find that the dominant driving forces, i.e., the
thermally induced permittivity gradient and the electrolyte Seebeck effect,
result in characteristic hydrodynamic screening. In comparison with recent
experimental data on single-stranded DNA (2 $\le$ n $\le$ 80), our theory
quantitatively describes the increase of the drift velocity up to n = 30; the
slowing-down of longer molecules is well accounted for by a simple model for
counterion condensation. It turns out that thermophoresis may change sign as a
function of n: For an appropriate choice of the salt-specific Seebeck
coefficient, short molecules move to the cold and long ones to the hot; this
could be used for separating DNA by molecular weight.

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The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th