Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Opioids for pain treatment of cancer: a knowledge maturity mapping   The conceptual structure of opioids, based on the bibliometric analysis of
4,935 articles of the Web of Science was constructed. The results were
processed identifying the most cited articles to extract the main connections
and frequencies of key words, authors, journals, countries, institutions, and
their tendencies and their connection and degree of collaboration. The temporal
tendencies, the word cloud, the keyword network, the evolution of words, author
production and the scientific production by country are analyzed in terms of
the increasing frequency in which opioids are employed to treat both cancerous
and non-cancerous pain.

25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess