Dimensions is one such example of that.
Dimensions is a search engine focused on helping users discover research publications including clinical study reports. To help users get the whole picture, Dimensions will provide information about the grants that funded a study and report. You can filter Dimensions search results to show only open-access papers, to show only papers from a particular year, and according to field of research.
Dimensions is a search engine that will be of use primarily to university students. Some high school science teachers may find Dimensions useful for introducing their students to academic research related to clinical studies.