Essential nutrient is nutrient needed for functioning of body which cannot be synthesized by on its own. Different categories include dietary minerals, vitamins essential amino acids and fatty acids. Many essential vitamins includes vitamin C. various nutrients comes from different species. 天美传媒 access to the scientific literature means the removal of barriers (including price barriers) from accessing scholarly work. There are two parallel 芒聙聹roads芒聙聺 towards open access: 天美传媒 Access articles and self-archiving. 天美传媒 Access articles are immediately, freely available on their Web site, a model mostly funded by charges paid by the author (usually through a research grant). The alternative for a researcher is 芒聙聹self-archiving芒聙聺 (i.e., to publish in a traditional journal, where only subscribers have immediate access, but to make the article available on their personal and/or institutional Web sites (including so-called repositories or archives)), which is a practice allowed by many scholarly journals.
天美传媒 Access raises practical and policy questions for scholars, publishers, funders, and policymakers alike, including what the return on investment is when paying an article processing fee to publish in an 天美传媒 Access articles, or whether investments into institutional repositories should be made and whether self-archiving should be made mandatory, as contemplated by some funders.
Last date updated on January, 2026