Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Effects of Counterions on Nano-confined DNA Thin Films
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat