open_access

The PMC Open Access Subset includes more than 3.4 million journal articles and preprints that are made available under
license terms that allow reuse.

Not all articles in PMC are available for text mining and other reuse, many have copyright protection, however articles
in the PMC Open Access Subset are made available under Creative Commons or similar licenses that generally allow more
liberal redistribution and reuse than a traditional copyrighted work.

The PMC Open Access Subset is one part of the PMC Article Datasets

PMC开放获取子集囊括了超过340万篇期刊文章和预印本，这些文献在许可协议下被授权允许复用。并非PMC中的所有文章都适用于文本挖掘和其他复用，众多文章受版权保护；然而，PMC开放获取子集中的文章则在创意共享或类似许可下提供，此类许可通常比传统版权作品更为宽松，允许更广泛的分发和复用。PMC开放获取子集是PMC文章数据集的一部分。