Generally speaking, abstraction is to avoid charts and the like. The following are the requirements of SCI for abstracts: Please provide a summary of conclusions and facts not exceeding 300 words. The purpose, main results and main conclusions of the study should be briefly explained. Footnotes, references and charts should be avoided in the abstract.

The number of words can be ignored, and the number of words in different journals is different. But the last two sentences are still of reference value.